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* [patch 00/10] memcg naturalization -rc5
@ 2011-11-08 21:23 ` Johannes Weiner
  0 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-11-08 21:23 UTC (permalink / raw)
  To: Andrew Morton
  Cc: KAMEZAWA Hiroyuki, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel

This is version 5 of the memcg naturalization patches.

They enable traditional page reclaim to find pages from the per-memcg
LRU lists, thereby getting rid of the double-LRU scheme (per global
zone in addition to per memcg-zone) and the required extra list head
per each page in the system.

The only change from version 4 is using the name `memcg' instead of
`mem' for memcg pointers in code added in the series.

This series is based on v3.2-rc1.

memcg users and distributions are waiting for this because of the
memory savings.  The changes for regular users that do not create
memcgs in addition to the root memcg are minimal, and even smaller for
users that disable the memcg feature at compile time.  Lastly, ongoing
memcg development, like the breaking up of zone->lru_lock, fixing the
soft limit implementation/memory guarantees and per-memcg reclaim
statistics, is already based on this.

Thanks!

 include/linux/memcontrol.h  |   73 +++--
 include/linux/mm_inline.h   |   21 +-
 include/linux/mmzone.h      |   10 +-
 include/linux/page_cgroup.h |   34 ---
 mm/memcontrol.c             |  693 ++++++++++++++++++++-----------------------
 mm/page_alloc.c             |    2 +-
 mm/page_cgroup.c            |   58 +----
 mm/swap.c                   |   24 +-
 mm/vmscan.c                 |  389 +++++++++++++++----------
 9 files changed, 643 insertions(+), 661 deletions(-)


^ permalink raw reply	[flat|nested] 32+ messages in thread
* [patch 00/10] memcg naturalization -rc5
@ 2011-11-08 21:23 ` Johannes Weiner
  0 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-11-08 21:23 UTC (permalink / raw)
  To: Andrew Morton
  Cc: KAMEZAWA Hiroyuki, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel

This is version 5 of the memcg naturalization patches.

They enable traditional page reclaim to find pages from the per-memcg
LRU lists, thereby getting rid of the double-LRU scheme (per global
zone in addition to per memcg-zone) and the required extra list head
per each page in the system.

The only change from version 4 is using the name `memcg' instead of
`mem' for memcg pointers in code added in the series.

This series is based on v3.2-rc1.

memcg users and distributions are waiting for this because of the
memory savings.  The changes for regular users that do not create
memcgs in addition to the root memcg are minimal, and even smaller for
users that disable the memcg feature at compile time.  Lastly, ongoing
memcg development, like the breaking up of zone->lru_lock, fixing the
soft limit implementation/memory guarantees and per-memcg reclaim
statistics, is already based on this.

Thanks!

 include/linux/memcontrol.h  |   73 +++--
 include/linux/mm_inline.h   |   21 +-
 include/linux/mmzone.h      |   10 +-
 include/linux/page_cgroup.h |   34 ---
 mm/memcontrol.c             |  693 ++++++++++++++++++++-----------------------
 mm/page_alloc.c             |    2 +-
 mm/page_cgroup.c            |   58 +----
 mm/swap.c                   |   24 +-
 mm/vmscan.c                 |  389 +++++++++++++++----------
 9 files changed, 643 insertions(+), 661 deletions(-)

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^ permalink raw reply	[flat|nested] 32+ messages in thread
* [patch 01/10] mm: memcg: consolidate hierarchy iteration primitives
  2011-11-08 21:23 ` Johannes Weiner
@ 2011-11-08 21:23   ` Johannes Weiner
  -1 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-11-08 21:23 UTC (permalink / raw)
  To: Andrew Morton
  Cc: KAMEZAWA Hiroyuki, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel

The memcg naturalization series:

Memory control groups are currently bolted onto the side of
traditional memory management in places where better integration would
be preferrable.  To reclaim memory, for example, memory control groups
maintain their own LRU list and reclaim strategy aside from the global
per-zone LRU list reclaim.  But an extra list head for each existing
page frame is expensive and maintaining it requires additional code.

This patchset disables the global per-zone LRU lists on memory cgroup
configurations and converts all its users to operate on the per-memory
cgroup lists instead.  As LRU pages are then exclusively on one list,
this saves two list pointers for each page frame in the system:

page_cgroup array size with 4G physical memory

  vanilla: [    0.000000] allocated 31457280 bytes of page_cgroup
  patched: [    0.000000] allocated 15728640 bytes of page_cgroup

At the same time, system performance for various workloads is
unaffected:

100G sparse file cat, 4G physical memory, 10 runs, to test for code
bloat in the traditional LRU handling and kswapd & direct reclaim
paths, without/with the memory controller configured in

  vanilla: 71.603(0.207) seconds
  patched: 71.640(0.156) seconds

  vanilla: 79.558(0.288) seconds
  patched: 77.233(0.147) seconds

100G sparse file cat in 1G memory cgroup, 10 runs, to test for code
bloat in the traditional memory cgroup LRU handling and reclaim path

  vanilla: 96.844(0.281) seconds
  patched: 94.454(0.311) seconds

4 unlimited memcgs running kbuild -j32 each, 4G physical memory, 500M
swap on SSD, 10 runs, to test for regressions in kswapd & direct
reclaim using per-memcg LRU lists with multiple memcgs and multiple
allocators within each memcg

  vanilla: 717.722(1.440) seconds [ 69720.100(11600.835) majfaults ]
  patched: 714.106(2.313) seconds [ 71109.300(14886.186) majfaults ]

16 unlimited memcgs running kbuild, 1900M hierarchical limit, 500M
swap on SSD, 10 runs, to test for regressions in hierarchical memcg
setups

  vanilla: 2742.058(1.992) seconds [ 26479.600(1736.737) majfaults ]
  patched: 2743.267(1.214) seconds [ 27240.700(1076.063) majfaults ]

This patch:

There are currently two different implementations of iterating over a
memory cgroup hierarchy tree.

Consolidate them into one worker function and base the convenience
looping-macros on top of it.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
---
 mm/memcontrol.c |  199 +++++++++++++++++++++----------------------------------
 1 files changed, 75 insertions(+), 124 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6aff93c..77049f7 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -787,83 +787,76 @@ struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
 	return memcg;
 }
 
-/* The caller has to guarantee "mem" exists before calling this */
-static struct mem_cgroup *mem_cgroup_start_loop(struct mem_cgroup *memcg)
+static struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
+					  struct mem_cgroup *prev,
+					  bool reclaim)
 {
-	struct cgroup_subsys_state *css;
-	int found;
+	struct mem_cgroup *memcg = NULL;
+	int id = 0;
 
-	if (!memcg) /* ROOT cgroup has the smallest ID */
-		return root_mem_cgroup; /*css_put/get against root is ignored*/
-	if (!memcg->use_hierarchy) {
-		if (css_tryget(&memcg->css))
-			return memcg;
-		return NULL;
-	}
-	rcu_read_lock();
-	/*
-	 * searching a memory cgroup which has the smallest ID under given
-	 * ROOT cgroup. (ID >= 1)
-	 */
-	css = css_get_next(&mem_cgroup_subsys, 1, &memcg->css, &found);
-	if (css && css_tryget(css))
-		memcg = container_of(css, struct mem_cgroup, css);
-	else
-		memcg = NULL;
-	rcu_read_unlock();
-	return memcg;
-}
+	if (!root)
+		root = root_mem_cgroup;
 
-static struct mem_cgroup *mem_cgroup_get_next(struct mem_cgroup *iter,
-					struct mem_cgroup *root,
-					bool cond)
-{
-	int nextid = css_id(&iter->css) + 1;
-	int found;
-	int hierarchy_used;
-	struct cgroup_subsys_state *css;
+	if (prev && !reclaim)
+		id = css_id(&prev->css);
 
-	hierarchy_used = iter->use_hierarchy;
+	if (prev && prev != root)
+		css_put(&prev->css);
 
-	css_put(&iter->css);
-	/* If no ROOT, walk all, ignore hierarchy */
-	if (!cond || (root && !hierarchy_used))
-		return NULL;
+	if (!root->use_hierarchy && root != root_mem_cgroup) {
+		if (prev)
+			return NULL;
+		return root;
+	}
 
-	if (!root)
-		root = root_mem_cgroup;
+	while (!memcg) {
+		struct cgroup_subsys_state *css;
 
-	do {
-		iter = NULL;
-		rcu_read_lock();
+		if (reclaim)
+			id = root->last_scanned_child;
 
-		css = css_get_next(&mem_cgroup_subsys, nextid,
-				&root->css, &found);
-		if (css && css_tryget(css))
-			iter = container_of(css, struct mem_cgroup, css);
+		rcu_read_lock();
+		css = css_get_next(&mem_cgroup_subsys, id + 1, &root->css, &id);
+		if (css) {
+			if (css == &root->css || css_tryget(css))
+				memcg = container_of(css,
+						     struct mem_cgroup, css);
+		} else
+			id = 0;
 		rcu_read_unlock();
-		/* If css is NULL, no more cgroups will be found */
-		nextid = found + 1;
-	} while (css && !iter);
 
-	return iter;
+		if (reclaim)
+			root->last_scanned_child = id;
+
+		if (prev && !css)
+			return NULL;
+	}
+	return memcg;
 }
-/*
- * for_eacn_mem_cgroup_tree() for visiting all cgroup under tree. Please
- * be careful that "break" loop is not allowed. We have reference count.
- * Instead of that modify "cond" to be false and "continue" to exit the loop.
- */
-#define for_each_mem_cgroup_tree_cond(iter, root, cond)	\
-	for (iter = mem_cgroup_start_loop(root);\
-	     iter != NULL;\
-	     iter = mem_cgroup_get_next(iter, root, cond))
 
-#define for_each_mem_cgroup_tree(iter, root) \
-	for_each_mem_cgroup_tree_cond(iter, root, true)
+static void mem_cgroup_iter_break(struct mem_cgroup *root,
+				  struct mem_cgroup *prev)
+{
+	if (!root)
+		root = root_mem_cgroup;
+	if (prev && prev != root)
+		css_put(&prev->css);
+}
 
-#define for_each_mem_cgroup_all(iter) \
-	for_each_mem_cgroup_tree_cond(iter, NULL, true)
+/*
+ * Iteration constructs for visiting all cgroups (under a tree).  If
+ * loops are exited prematurely (break), mem_cgroup_iter_break() must
+ * be used for reference counting.
+ */
+#define for_each_mem_cgroup_tree(iter, root)		\
+	for (iter = mem_cgroup_iter(root, NULL, false);	\
+	     iter != NULL;				\
+	     iter = mem_cgroup_iter(root, iter, false))
 
+#define for_each_mem_cgroup(iter)			\
+	for (iter = mem_cgroup_iter(NULL, NULL, false);	\
+	     iter != NULL;				\
+	     iter = mem_cgroup_iter(NULL, iter, false))
 
 static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
 {
@@ -1470,43 +1463,6 @@ u64 mem_cgroup_get_limit(struct mem_cgroup *memcg)
 	return min(limit, memsw);
 }
 
-/*
- * Visit the first child (need not be the first child as per the ordering
- * of the cgroup list, since we track last_scanned_child) of @mem and use
- * that to reclaim free pages from.
- */
-static struct mem_cgroup *
-mem_cgroup_select_victim(struct mem_cgroup *root_memcg)
-{
-	struct mem_cgroup *ret = NULL;
-	struct cgroup_subsys_state *css;
-	int nextid, found;
-
-	if (!root_memcg->use_hierarchy) {
-		css_get(&root_memcg->css);
-		ret = root_memcg;
-	}
-
-	while (!ret) {
-		rcu_read_lock();
-		nextid = root_memcg->last_scanned_child + 1;
-		css = css_get_next(&mem_cgroup_subsys, nextid, &root_memcg->css,
-				   &found);
-		if (css && css_tryget(css))
-			ret = container_of(css, struct mem_cgroup, css);
-
-		rcu_read_unlock();
-		/* Updates scanning parameter */
-		if (!css) {
-			/* this means start scan from ID:1 */
-			root_memcg->last_scanned_child = 0;
-		} else
-			root_memcg->last_scanned_child = found;
-	}
-
-	return ret;
-}
-
 /**
  * test_mem_cgroup_node_reclaimable
  * @mem: the target memcg
@@ -1662,7 +1618,7 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
 						unsigned long reclaim_options,
 						unsigned long *total_scanned)
 {
-	struct mem_cgroup *victim;
+	struct mem_cgroup *victim = NULL;
 	int ret, total = 0;
 	int loop = 0;
 	bool noswap = reclaim_options & MEM_CGROUP_RECLAIM_NOSWAP;
@@ -1678,8 +1634,8 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
 		noswap = true;
 
 	while (1) {
-		victim = mem_cgroup_select_victim(root_memcg);
-		if (victim == root_memcg) {
+		victim = mem_cgroup_iter(root_memcg, victim, true);
+		if (!victim) {
 			loop++;
 			/*
 			 * We are not draining per cpu cached charges during
@@ -1695,10 +1651,8 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
 				 * anything, it might because there are
 				 * no reclaimable pages under this hierarchy
 				 */
-				if (!check_soft || !total) {
-					css_put(&victim->css);
+				if (!check_soft || !total)
 					break;
-				}
 				/*
 				 * We want to do more targeted reclaim.
 				 * excess >> 2 is not to excessive so as to
@@ -1706,15 +1660,13 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
 				 * coming back to reclaim from this cgroup
 				 */
 				if (total >= (excess >> 2) ||
-					(loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) {
-					css_put(&victim->css);
+					(loop > MEM_CGROUP_MAX_RECLAIM_LOOPS))
 					break;
-				}
 			}
+			continue;
 		}
 		if (!mem_cgroup_reclaimable(victim, noswap)) {
 			/* this cgroup's local usage == 0 */
-			css_put(&victim->css);
 			continue;
 		}
 		/* we use swappiness of local cgroup */
@@ -1725,21 +1677,21 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
 		} else
 			ret = try_to_free_mem_cgroup_pages(victim, gfp_mask,
 						noswap);
-		css_put(&victim->css);
+		total += ret;
 		/*
 		 * At shrinking usage, we can't check we should stop here or
 		 * reclaim more. It's depends on callers. last_scanned_child
 		 * will work enough for keeping fairness under tree.
 		 */
 		if (shrink)
-			return ret;
-		total += ret;
+			break;
 		if (check_soft) {
 			if (!res_counter_soft_limit_excess(&root_memcg->res))
-				return total;
+				break;
 		} else if (mem_cgroup_margin(root_memcg))
-			return total;
+			break;
 	}
+	mem_cgroup_iter_break(root_memcg, victim);
 	return total;
 }
 
@@ -1751,16 +1703,16 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
 static bool mem_cgroup_oom_lock(struct mem_cgroup *memcg)
 {
 	struct mem_cgroup *iter, *failed = NULL;
-	bool cond = true;
 
-	for_each_mem_cgroup_tree_cond(iter, memcg, cond) {
+	for_each_mem_cgroup_tree(iter, memcg) {
 		if (iter->oom_lock) {
 			/*
 			 * this subtree of our hierarchy is already locked
 			 * so we cannot give a lock.
 			 */
 			failed = iter;
-			cond = false;
+			mem_cgroup_iter_break(memcg, iter);
+			break;
 		} else
 			iter->oom_lock = true;
 	}
@@ -1772,11 +1724,10 @@ static bool mem_cgroup_oom_lock(struct mem_cgroup *memcg)
 	 * OK, we failed to lock the whole subtree so we have to clean up
 	 * what we set up to the failing subtree
 	 */
-	cond = true;
-	for_each_mem_cgroup_tree_cond(iter, memcg, cond) {
+	for_each_mem_cgroup_tree(iter, memcg) {
 		if (iter == failed) {
-			cond = false;
-			continue;
+			mem_cgroup_iter_break(memcg, iter);
+			break;
 		}
 		iter->oom_lock = false;
 	}
@@ -2172,7 +2123,7 @@ static int __cpuinit memcg_cpu_hotplug_callback(struct notifier_block *nb,
 	struct mem_cgroup *iter;
 
 	if ((action == CPU_ONLINE)) {
-		for_each_mem_cgroup_all(iter)
+		for_each_mem_cgroup(iter)
 			synchronize_mem_cgroup_on_move(iter, cpu);
 		return NOTIFY_OK;
 	}
@@ -2180,7 +2131,7 @@ static int __cpuinit memcg_cpu_hotplug_callback(struct notifier_block *nb,
 	if ((action != CPU_DEAD) || action != CPU_DEAD_FROZEN)
 		return NOTIFY_OK;
 
-	for_each_mem_cgroup_all(iter)
+	for_each_mem_cgroup(iter)
 		mem_cgroup_drain_pcp_counter(iter, cpu);
 
 	stock = &per_cpu(memcg_stock, cpu);
-- 
1.7.6.4


^ permalink raw reply related	[flat|nested] 32+ messages in thread
* [patch 01/10] mm: memcg: consolidate hierarchy iteration primitives
@ 2011-11-08 21:23   ` Johannes Weiner
  0 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-11-08 21:23 UTC (permalink / raw)
  To: Andrew Morton
  Cc: KAMEZAWA Hiroyuki, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel

The memcg naturalization series:

Memory control groups are currently bolted onto the side of
traditional memory management in places where better integration would
be preferrable.  To reclaim memory, for example, memory control groups
maintain their own LRU list and reclaim strategy aside from the global
per-zone LRU list reclaim.  But an extra list head for each existing
page frame is expensive and maintaining it requires additional code.

This patchset disables the global per-zone LRU lists on memory cgroup
configurations and converts all its users to operate on the per-memory
cgroup lists instead.  As LRU pages are then exclusively on one list,
this saves two list pointers for each page frame in the system:

page_cgroup array size with 4G physical memory

  vanilla: [    0.000000] allocated 31457280 bytes of page_cgroup
  patched: [    0.000000] allocated 15728640 bytes of page_cgroup

At the same time, system performance for various workloads is
unaffected:

100G sparse file cat, 4G physical memory, 10 runs, to test for code
bloat in the traditional LRU handling and kswapd & direct reclaim
paths, without/with the memory controller configured in

  vanilla: 71.603(0.207) seconds
  patched: 71.640(0.156) seconds

  vanilla: 79.558(0.288) seconds
  patched: 77.233(0.147) seconds

100G sparse file cat in 1G memory cgroup, 10 runs, to test for code
bloat in the traditional memory cgroup LRU handling and reclaim path

  vanilla: 96.844(0.281) seconds
  patched: 94.454(0.311) seconds

4 unlimited memcgs running kbuild -j32 each, 4G physical memory, 500M
swap on SSD, 10 runs, to test for regressions in kswapd & direct
reclaim using per-memcg LRU lists with multiple memcgs and multiple
allocators within each memcg

  vanilla: 717.722(1.440) seconds [ 69720.100(11600.835) majfaults ]
  patched: 714.106(2.313) seconds [ 71109.300(14886.186) majfaults ]

16 unlimited memcgs running kbuild, 1900M hierarchical limit, 500M
swap on SSD, 10 runs, to test for regressions in hierarchical memcg
setups

  vanilla: 2742.058(1.992) seconds [ 26479.600(1736.737) majfaults ]
  patched: 2743.267(1.214) seconds [ 27240.700(1076.063) majfaults ]

This patch:

There are currently two different implementations of iterating over a
memory cgroup hierarchy tree.

Consolidate them into one worker function and base the convenience
looping-macros on top of it.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
---
 mm/memcontrol.c |  199 +++++++++++++++++++++----------------------------------
 1 files changed, 75 insertions(+), 124 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6aff93c..77049f7 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -787,83 +787,76 @@ struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
 	return memcg;
 }
 
-/* The caller has to guarantee "mem" exists before calling this */
-static struct mem_cgroup *mem_cgroup_start_loop(struct mem_cgroup *memcg)
+static struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
+					  struct mem_cgroup *prev,
+					  bool reclaim)
 {
-	struct cgroup_subsys_state *css;
-	int found;
+	struct mem_cgroup *memcg = NULL;
+	int id = 0;
 
-	if (!memcg) /* ROOT cgroup has the smallest ID */
-		return root_mem_cgroup; /*css_put/get against root is ignored*/
-	if (!memcg->use_hierarchy) {
-		if (css_tryget(&memcg->css))
-			return memcg;
-		return NULL;
-	}
-	rcu_read_lock();
-	/*
-	 * searching a memory cgroup which has the smallest ID under given
-	 * ROOT cgroup. (ID >= 1)
-	 */
-	css = css_get_next(&mem_cgroup_subsys, 1, &memcg->css, &found);
-	if (css && css_tryget(css))
-		memcg = container_of(css, struct mem_cgroup, css);
-	else
-		memcg = NULL;
-	rcu_read_unlock();
-	return memcg;
-}
+	if (!root)
+		root = root_mem_cgroup;
 
-static struct mem_cgroup *mem_cgroup_get_next(struct mem_cgroup *iter,
-					struct mem_cgroup *root,
-					bool cond)
-{
-	int nextid = css_id(&iter->css) + 1;
-	int found;
-	int hierarchy_used;
-	struct cgroup_subsys_state *css;
+	if (prev && !reclaim)
+		id = css_id(&prev->css);
 
-	hierarchy_used = iter->use_hierarchy;
+	if (prev && prev != root)
+		css_put(&prev->css);
 
-	css_put(&iter->css);
-	/* If no ROOT, walk all, ignore hierarchy */
-	if (!cond || (root && !hierarchy_used))
-		return NULL;
+	if (!root->use_hierarchy && root != root_mem_cgroup) {
+		if (prev)
+			return NULL;
+		return root;
+	}
 
-	if (!root)
-		root = root_mem_cgroup;
+	while (!memcg) {
+		struct cgroup_subsys_state *css;
 
-	do {
-		iter = NULL;
-		rcu_read_lock();
+		if (reclaim)
+			id = root->last_scanned_child;
 
-		css = css_get_next(&mem_cgroup_subsys, nextid,
-				&root->css, &found);
-		if (css && css_tryget(css))
-			iter = container_of(css, struct mem_cgroup, css);
+		rcu_read_lock();
+		css = css_get_next(&mem_cgroup_subsys, id + 1, &root->css, &id);
+		if (css) {
+			if (css == &root->css || css_tryget(css))
+				memcg = container_of(css,
+						     struct mem_cgroup, css);
+		} else
+			id = 0;
 		rcu_read_unlock();
-		/* If css is NULL, no more cgroups will be found */
-		nextid = found + 1;
-	} while (css && !iter);
 
-	return iter;
+		if (reclaim)
+			root->last_scanned_child = id;
+
+		if (prev && !css)
+			return NULL;
+	}
+	return memcg;
 }
-/*
- * for_eacn_mem_cgroup_tree() for visiting all cgroup under tree. Please
- * be careful that "break" loop is not allowed. We have reference count.
- * Instead of that modify "cond" to be false and "continue" to exit the loop.
- */
-#define for_each_mem_cgroup_tree_cond(iter, root, cond)	\
-	for (iter = mem_cgroup_start_loop(root);\
-	     iter != NULL;\
-	     iter = mem_cgroup_get_next(iter, root, cond))
 
-#define for_each_mem_cgroup_tree(iter, root) \
-	for_each_mem_cgroup_tree_cond(iter, root, true)
+static void mem_cgroup_iter_break(struct mem_cgroup *root,
+				  struct mem_cgroup *prev)
+{
+	if (!root)
+		root = root_mem_cgroup;
+	if (prev && prev != root)
+		css_put(&prev->css);
+}
 
-#define for_each_mem_cgroup_all(iter) \
-	for_each_mem_cgroup_tree_cond(iter, NULL, true)
+/*
+ * Iteration constructs for visiting all cgroups (under a tree).  If
+ * loops are exited prematurely (break), mem_cgroup_iter_break() must
+ * be used for reference counting.
+ */
+#define for_each_mem_cgroup_tree(iter, root)		\
+	for (iter = mem_cgroup_iter(root, NULL, false);	\
+	     iter != NULL;				\
+	     iter = mem_cgroup_iter(root, iter, false))
 
+#define for_each_mem_cgroup(iter)			\
+	for (iter = mem_cgroup_iter(NULL, NULL, false);	\
+	     iter != NULL;				\
+	     iter = mem_cgroup_iter(NULL, iter, false))
 
 static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
 {
@@ -1470,43 +1463,6 @@ u64 mem_cgroup_get_limit(struct mem_cgroup *memcg)
 	return min(limit, memsw);
 }
 
-/*
- * Visit the first child (need not be the first child as per the ordering
- * of the cgroup list, since we track last_scanned_child) of @mem and use
- * that to reclaim free pages from.
- */
-static struct mem_cgroup *
-mem_cgroup_select_victim(struct mem_cgroup *root_memcg)
-{
-	struct mem_cgroup *ret = NULL;
-	struct cgroup_subsys_state *css;
-	int nextid, found;
-
-	if (!root_memcg->use_hierarchy) {
-		css_get(&root_memcg->css);
-		ret = root_memcg;
-	}
-
-	while (!ret) {
-		rcu_read_lock();
-		nextid = root_memcg->last_scanned_child + 1;
-		css = css_get_next(&mem_cgroup_subsys, nextid, &root_memcg->css,
-				   &found);
-		if (css && css_tryget(css))
-			ret = container_of(css, struct mem_cgroup, css);
-
-		rcu_read_unlock();
-		/* Updates scanning parameter */
-		if (!css) {
-			/* this means start scan from ID:1 */
-			root_memcg->last_scanned_child = 0;
-		} else
-			root_memcg->last_scanned_child = found;
-	}
-
-	return ret;
-}
-
 /**
  * test_mem_cgroup_node_reclaimable
  * @mem: the target memcg
@@ -1662,7 +1618,7 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
 						unsigned long reclaim_options,
 						unsigned long *total_scanned)
 {
-	struct mem_cgroup *victim;
+	struct mem_cgroup *victim = NULL;
 	int ret, total = 0;
 	int loop = 0;
 	bool noswap = reclaim_options & MEM_CGROUP_RECLAIM_NOSWAP;
@@ -1678,8 +1634,8 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
 		noswap = true;
 
 	while (1) {
-		victim = mem_cgroup_select_victim(root_memcg);
-		if (victim == root_memcg) {
+		victim = mem_cgroup_iter(root_memcg, victim, true);
+		if (!victim) {
 			loop++;
 			/*
 			 * We are not draining per cpu cached charges during
@@ -1695,10 +1651,8 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
 				 * anything, it might because there are
 				 * no reclaimable pages under this hierarchy
 				 */
-				if (!check_soft || !total) {
-					css_put(&victim->css);
+				if (!check_soft || !total)
 					break;
-				}
 				/*
 				 * We want to do more targeted reclaim.
 				 * excess >> 2 is not to excessive so as to
@@ -1706,15 +1660,13 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
 				 * coming back to reclaim from this cgroup
 				 */
 				if (total >= (excess >> 2) ||
-					(loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) {
-					css_put(&victim->css);
+					(loop > MEM_CGROUP_MAX_RECLAIM_LOOPS))
 					break;
-				}
 			}
+			continue;
 		}
 		if (!mem_cgroup_reclaimable(victim, noswap)) {
 			/* this cgroup's local usage == 0 */
-			css_put(&victim->css);
 			continue;
 		}
 		/* we use swappiness of local cgroup */
@@ -1725,21 +1677,21 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
 		} else
 			ret = try_to_free_mem_cgroup_pages(victim, gfp_mask,
 						noswap);
-		css_put(&victim->css);
+		total += ret;
 		/*
 		 * At shrinking usage, we can't check we should stop here or
 		 * reclaim more. It's depends on callers. last_scanned_child
 		 * will work enough for keeping fairness under tree.
 		 */
 		if (shrink)
-			return ret;
-		total += ret;
+			break;
 		if (check_soft) {
 			if (!res_counter_soft_limit_excess(&root_memcg->res))
-				return total;
+				break;
 		} else if (mem_cgroup_margin(root_memcg))
-			return total;
+			break;
 	}
+	mem_cgroup_iter_break(root_memcg, victim);
 	return total;
 }
 
@@ -1751,16 +1703,16 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
 static bool mem_cgroup_oom_lock(struct mem_cgroup *memcg)
 {
 	struct mem_cgroup *iter, *failed = NULL;
-	bool cond = true;
 
-	for_each_mem_cgroup_tree_cond(iter, memcg, cond) {
+	for_each_mem_cgroup_tree(iter, memcg) {
 		if (iter->oom_lock) {
 			/*
 			 * this subtree of our hierarchy is already locked
 			 * so we cannot give a lock.
 			 */
 			failed = iter;
-			cond = false;
+			mem_cgroup_iter_break(memcg, iter);
+			break;
 		} else
 			iter->oom_lock = true;
 	}
@@ -1772,11 +1724,10 @@ static bool mem_cgroup_oom_lock(struct mem_cgroup *memcg)
 	 * OK, we failed to lock the whole subtree so we have to clean up
 	 * what we set up to the failing subtree
 	 */
-	cond = true;
-	for_each_mem_cgroup_tree_cond(iter, memcg, cond) {
+	for_each_mem_cgroup_tree(iter, memcg) {
 		if (iter == failed) {
-			cond = false;
-			continue;
+			mem_cgroup_iter_break(memcg, iter);
+			break;
 		}
 		iter->oom_lock = false;
 	}
@@ -2172,7 +2123,7 @@ static int __cpuinit memcg_cpu_hotplug_callback(struct notifier_block *nb,
 	struct mem_cgroup *iter;
 
 	if ((action == CPU_ONLINE)) {
-		for_each_mem_cgroup_all(iter)
+		for_each_mem_cgroup(iter)
 			synchronize_mem_cgroup_on_move(iter, cpu);
 		return NOTIFY_OK;
 	}
@@ -2180,7 +2131,7 @@ static int __cpuinit memcg_cpu_hotplug_callback(struct notifier_block *nb,
 	if ((action != CPU_DEAD) || action != CPU_DEAD_FROZEN)
 		return NOTIFY_OK;
 
-	for_each_mem_cgroup_all(iter)
+	for_each_mem_cgroup(iter)
 		mem_cgroup_drain_pcp_counter(iter, cpu);
 
 	stock = &per_cpu(memcg_stock, cpu);
-- 
1.7.6.4

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^ permalink raw reply related	[flat|nested] 32+ messages in thread
* [patch 02/10] mm: vmscan: distinguish global reclaim from global LRU scanning
  2011-11-08 21:23 ` Johannes Weiner
@ 2011-11-08 21:23   ` Johannes Weiner
  -1 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-11-08 21:23 UTC (permalink / raw)
  To: Andrew Morton
  Cc: KAMEZAWA Hiroyuki, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel

The traditional zone reclaim code is scanning the per-zone LRU lists
during direct reclaim and kswapd, and the per-zone per-memory cgroup
LRU lists when reclaiming on behalf of a memory cgroup limit.

Subsequent patches will convert the traditional reclaim code to
reclaim exclusively from the per-memory cgroup LRU lists.  As a
result, using the predicate for which LRU list is scanned will no
longer be appropriate to tell global reclaim from limit reclaim.

This patch adds a global_reclaim() predicate to tell direct/kswapd
reclaim from memory cgroup limit reclaim and substitutes it in all
places where currently scanning_global_lru() is used for that.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
---
 mm/vmscan.c |   62 +++++++++++++++++++++++++++++++++++-----------------------
 1 files changed, 37 insertions(+), 25 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index a1893c0..189597e 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -153,9 +153,25 @@ static LIST_HEAD(shrinker_list);
 static DECLARE_RWSEM(shrinker_rwsem);
 
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR
-#define scanning_global_lru(sc)	(!(sc)->mem_cgroup)
+static bool global_reclaim(struct scan_control *sc)
+{
+	return !sc->mem_cgroup;
+}
+
+static bool scanning_global_lru(struct scan_control *sc)
+{
+	return !sc->mem_cgroup;
+}
 #else
-#define scanning_global_lru(sc)	(1)
+static bool global_reclaim(struct scan_control *sc)
+{
+	return true;
+}
+
+static bool scanning_global_lru(struct scan_control *sc)
+{
+	return true;
+}
 #endif
 
 static struct zone_reclaim_stat *get_reclaim_stat(struct zone *zone,
@@ -1006,7 +1022,7 @@ keep_lumpy:
 	 * back off and wait for congestion to clear because further reclaim
 	 * will encounter the same problem
 	 */
-	if (nr_dirty && nr_dirty == nr_congested && scanning_global_lru(sc))
+	if (nr_dirty && nr_dirty == nr_congested && global_reclaim(sc))
 		zone_set_flag(zone, ZONE_CONGESTED);
 
 	free_page_list(&free_pages);
@@ -1325,7 +1341,7 @@ static int too_many_isolated(struct zone *zone, int file,
 	if (current_is_kswapd())
 		return 0;
 
-	if (!scanning_global_lru(sc))
+	if (!global_reclaim(sc))
 		return 0;
 
 	if (file) {
@@ -1503,6 +1519,12 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
 	if (scanning_global_lru(sc)) {
 		nr_taken = isolate_pages_global(nr_to_scan, &page_list,
 			&nr_scanned, sc->order, reclaim_mode, zone, 0, file);
+	} else {
+		nr_taken = mem_cgroup_isolate_pages(nr_to_scan, &page_list,
+			&nr_scanned, sc->order, reclaim_mode, zone,
+			sc->mem_cgroup, 0, file);
+	}
+	if (global_reclaim(sc)) {
 		zone->pages_scanned += nr_scanned;
 		if (current_is_kswapd())
 			__count_zone_vm_events(PGSCAN_KSWAPD, zone,
@@ -1510,14 +1532,6 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
 		else
 			__count_zone_vm_events(PGSCAN_DIRECT, zone,
 					       nr_scanned);
-	} else {
-		nr_taken = mem_cgroup_isolate_pages(nr_to_scan, &page_list,
-			&nr_scanned, sc->order, reclaim_mode, zone,
-			sc->mem_cgroup, 0, file);
-		/*
-		 * mem_cgroup_isolate_pages() keeps track of
-		 * scanned pages on its own.
-		 */
 	}
 
 	if (nr_taken == 0) {
@@ -1658,18 +1672,16 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 						&pgscanned, sc->order,
 						reclaim_mode, zone,
 						1, file);
-		zone->pages_scanned += pgscanned;
 	} else {
 		nr_taken = mem_cgroup_isolate_pages(nr_pages, &l_hold,
 						&pgscanned, sc->order,
 						reclaim_mode, zone,
 						sc->mem_cgroup, 1, file);
-		/*
-		 * mem_cgroup_isolate_pages() keeps track of
-		 * scanned pages on its own.
-		 */
 	}
 
+	if (global_reclaim(sc))
+		zone->pages_scanned += pgscanned;
+
 	reclaim_stat->recent_scanned[file] += nr_taken;
 
 	__count_zone_vm_events(PGREFILL, zone, pgscanned);
@@ -1839,7 +1851,7 @@ static unsigned long shrink_list(enum lru_list lru, unsigned long nr_to_scan,
 
 static int vmscan_swappiness(struct scan_control *sc)
 {
-	if (scanning_global_lru(sc))
+	if (global_reclaim(sc))
 		return vm_swappiness;
 	return mem_cgroup_swappiness(sc->mem_cgroup);
 }
@@ -1874,9 +1886,9 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
 	 * latencies, so it's better to scan a minimum amount there as
 	 * well.
 	 */
-	if (scanning_global_lru(sc) && current_is_kswapd())
+	if (current_is_kswapd())
 		force_scan = true;
-	if (!scanning_global_lru(sc))
+	if (!global_reclaim(sc))
 		force_scan = true;
 
 	/* If we have no swap space, do not bother scanning anon pages. */
@@ -1893,7 +1905,7 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
 	file  = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_FILE) +
 		zone_nr_lru_pages(zone, sc, LRU_INACTIVE_FILE);
 
-	if (scanning_global_lru(sc)) {
+	if (global_reclaim(sc)) {
 		free  = zone_page_state(zone, NR_FREE_PAGES);
 		/* If we have very few page cache pages,
 		   force-scan anon pages. */
@@ -2125,7 +2137,7 @@ static bool shrink_zones(int priority, struct zonelist *zonelist,
 		 * Take care memory controller reclaiming has small influence
 		 * to global LRU.
 		 */
-		if (scanning_global_lru(sc)) {
+		if (global_reclaim(sc)) {
 			if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
 				continue;
 			if (zone->all_unreclaimable && priority != DEF_PRIORITY)
@@ -2223,7 +2235,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
 	get_mems_allowed();
 	delayacct_freepages_start();
 
-	if (scanning_global_lru(sc))
+	if (global_reclaim(sc))
 		count_vm_event(ALLOCSTALL);
 
 	for (priority = DEF_PRIORITY; priority >= 0; priority--) {
@@ -2237,7 +2249,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
 		 * Don't shrink slabs when reclaiming memory from
 		 * over limit cgroups
 		 */
-		if (scanning_global_lru(sc)) {
+		if (global_reclaim(sc)) {
 			unsigned long lru_pages = 0;
 			for_each_zone_zonelist(zone, z, zonelist,
 					gfp_zone(sc->gfp_mask)) {
@@ -2299,7 +2311,7 @@ out:
 		return 0;
 
 	/* top priority shrink_zones still had more to do? don't OOM, then */
-	if (scanning_global_lru(sc) && !all_unreclaimable(zonelist, sc))
+	if (global_reclaim(sc) && !all_unreclaimable(zonelist, sc))
 		return 1;
 
 	return 0;
-- 
1.7.6.4


^ permalink raw reply related	[flat|nested] 32+ messages in thread
* [patch 02/10] mm: vmscan: distinguish global reclaim from global LRU scanning
@ 2011-11-08 21:23   ` Johannes Weiner
  0 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-11-08 21:23 UTC (permalink / raw)
  To: Andrew Morton
  Cc: KAMEZAWA Hiroyuki, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel

The traditional zone reclaim code is scanning the per-zone LRU lists
during direct reclaim and kswapd, and the per-zone per-memory cgroup
LRU lists when reclaiming on behalf of a memory cgroup limit.

Subsequent patches will convert the traditional reclaim code to
reclaim exclusively from the per-memory cgroup LRU lists.  As a
result, using the predicate for which LRU list is scanned will no
longer be appropriate to tell global reclaim from limit reclaim.

This patch adds a global_reclaim() predicate to tell direct/kswapd
reclaim from memory cgroup limit reclaim and substitutes it in all
places where currently scanning_global_lru() is used for that.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
---
 mm/vmscan.c |   62 +++++++++++++++++++++++++++++++++++-----------------------
 1 files changed, 37 insertions(+), 25 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index a1893c0..189597e 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -153,9 +153,25 @@ static LIST_HEAD(shrinker_list);
 static DECLARE_RWSEM(shrinker_rwsem);
 
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR
-#define scanning_global_lru(sc)	(!(sc)->mem_cgroup)
+static bool global_reclaim(struct scan_control *sc)
+{
+	return !sc->mem_cgroup;
+}
+
+static bool scanning_global_lru(struct scan_control *sc)
+{
+	return !sc->mem_cgroup;
+}
 #else
-#define scanning_global_lru(sc)	(1)
+static bool global_reclaim(struct scan_control *sc)
+{
+	return true;
+}
+
+static bool scanning_global_lru(struct scan_control *sc)
+{
+	return true;
+}
 #endif
 
 static struct zone_reclaim_stat *get_reclaim_stat(struct zone *zone,
@@ -1006,7 +1022,7 @@ keep_lumpy:
 	 * back off and wait for congestion to clear because further reclaim
 	 * will encounter the same problem
 	 */
-	if (nr_dirty && nr_dirty == nr_congested && scanning_global_lru(sc))
+	if (nr_dirty && nr_dirty == nr_congested && global_reclaim(sc))
 		zone_set_flag(zone, ZONE_CONGESTED);
 
 	free_page_list(&free_pages);
@@ -1325,7 +1341,7 @@ static int too_many_isolated(struct zone *zone, int file,
 	if (current_is_kswapd())
 		return 0;
 
-	if (!scanning_global_lru(sc))
+	if (!global_reclaim(sc))
 		return 0;
 
 	if (file) {
@@ -1503,6 +1519,12 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
 	if (scanning_global_lru(sc)) {
 		nr_taken = isolate_pages_global(nr_to_scan, &page_list,
 			&nr_scanned, sc->order, reclaim_mode, zone, 0, file);
+	} else {
+		nr_taken = mem_cgroup_isolate_pages(nr_to_scan, &page_list,
+			&nr_scanned, sc->order, reclaim_mode, zone,
+			sc->mem_cgroup, 0, file);
+	}
+	if (global_reclaim(sc)) {
 		zone->pages_scanned += nr_scanned;
 		if (current_is_kswapd())
 			__count_zone_vm_events(PGSCAN_KSWAPD, zone,
@@ -1510,14 +1532,6 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
 		else
 			__count_zone_vm_events(PGSCAN_DIRECT, zone,
 					       nr_scanned);
-	} else {
-		nr_taken = mem_cgroup_isolate_pages(nr_to_scan, &page_list,
-			&nr_scanned, sc->order, reclaim_mode, zone,
-			sc->mem_cgroup, 0, file);
-		/*
-		 * mem_cgroup_isolate_pages() keeps track of
-		 * scanned pages on its own.
-		 */
 	}
 
 	if (nr_taken == 0) {
@@ -1658,18 +1672,16 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 						&pgscanned, sc->order,
 						reclaim_mode, zone,
 						1, file);
-		zone->pages_scanned += pgscanned;
 	} else {
 		nr_taken = mem_cgroup_isolate_pages(nr_pages, &l_hold,
 						&pgscanned, sc->order,
 						reclaim_mode, zone,
 						sc->mem_cgroup, 1, file);
-		/*
-		 * mem_cgroup_isolate_pages() keeps track of
-		 * scanned pages on its own.
-		 */
 	}
 
+	if (global_reclaim(sc))
+		zone->pages_scanned += pgscanned;
+
 	reclaim_stat->recent_scanned[file] += nr_taken;
 
 	__count_zone_vm_events(PGREFILL, zone, pgscanned);
@@ -1839,7 +1851,7 @@ static unsigned long shrink_list(enum lru_list lru, unsigned long nr_to_scan,
 
 static int vmscan_swappiness(struct scan_control *sc)
 {
-	if (scanning_global_lru(sc))
+	if (global_reclaim(sc))
 		return vm_swappiness;
 	return mem_cgroup_swappiness(sc->mem_cgroup);
 }
@@ -1874,9 +1886,9 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
 	 * latencies, so it's better to scan a minimum amount there as
 	 * well.
 	 */
-	if (scanning_global_lru(sc) && current_is_kswapd())
+	if (current_is_kswapd())
 		force_scan = true;
-	if (!scanning_global_lru(sc))
+	if (!global_reclaim(sc))
 		force_scan = true;
 
 	/* If we have no swap space, do not bother scanning anon pages. */
@@ -1893,7 +1905,7 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
 	file  = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_FILE) +
 		zone_nr_lru_pages(zone, sc, LRU_INACTIVE_FILE);
 
-	if (scanning_global_lru(sc)) {
+	if (global_reclaim(sc)) {
 		free  = zone_page_state(zone, NR_FREE_PAGES);
 		/* If we have very few page cache pages,
 		   force-scan anon pages. */
@@ -2125,7 +2137,7 @@ static bool shrink_zones(int priority, struct zonelist *zonelist,
 		 * Take care memory controller reclaiming has small influence
 		 * to global LRU.
 		 */
-		if (scanning_global_lru(sc)) {
+		if (global_reclaim(sc)) {
 			if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
 				continue;
 			if (zone->all_unreclaimable && priority != DEF_PRIORITY)
@@ -2223,7 +2235,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
 	get_mems_allowed();
 	delayacct_freepages_start();
 
-	if (scanning_global_lru(sc))
+	if (global_reclaim(sc))
 		count_vm_event(ALLOCSTALL);
 
 	for (priority = DEF_PRIORITY; priority >= 0; priority--) {
@@ -2237,7 +2249,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
 		 * Don't shrink slabs when reclaiming memory from
 		 * over limit cgroups
 		 */
-		if (scanning_global_lru(sc)) {
+		if (global_reclaim(sc)) {
 			unsigned long lru_pages = 0;
 			for_each_zone_zonelist(zone, z, zonelist,
 					gfp_zone(sc->gfp_mask)) {
@@ -2299,7 +2311,7 @@ out:
 		return 0;
 
 	/* top priority shrink_zones still had more to do? don't OOM, then */
-	if (scanning_global_lru(sc) && !all_unreclaimable(zonelist, sc))
+	if (global_reclaim(sc) && !all_unreclaimable(zonelist, sc))
 		return 1;
 
 	return 0;
-- 
1.7.6.4

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^ permalink raw reply related	[flat|nested] 32+ messages in thread
* [patch 03/10] mm: vmscan: distinguish between memcg triggering reclaim and memcg being scanned
  2011-11-08 21:23 ` Johannes Weiner
@ 2011-11-08 21:23   ` Johannes Weiner
  -1 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-11-08 21:23 UTC (permalink / raw)
  To: Andrew Morton
  Cc: KAMEZAWA Hiroyuki, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel

Memory cgroup hierarchies are currently handled completely outside of
the traditional reclaim code, which is invoked with a single memory
cgroup as an argument for the whole call stack.

Subsequent patches will switch this code to do hierarchical reclaim,
so there needs to be a distinction between a) the memory cgroup that
is triggering reclaim due to hitting its limit and b) the memory
cgroup that is being scanned as a child of a).

This patch introduces a struct mem_cgroup_zone that contains the
combination of the memory cgroup and the zone being scanned, which is
then passed down the stack instead of the zone argument.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
---
 mm/vmscan.c |  249 +++++++++++++++++++++++++++++++++--------------------------
 1 files changed, 141 insertions(+), 108 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 189597e..b8e22a9 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -103,8 +103,11 @@ struct scan_control {
 	 */
 	reclaim_mode_t reclaim_mode;
 
-	/* Which cgroup do we reclaim from */
-	struct mem_cgroup *mem_cgroup;
+	/*
+	 * The memory cgroup that hit its limit and as a result is the
+	 * primary target of this reclaim invocation.
+	 */
+	struct mem_cgroup *target_mem_cgroup;
 
 	/*
 	 * Nodemask of nodes allowed by the caller. If NULL, all nodes
@@ -113,6 +116,11 @@ struct scan_control {
 	nodemask_t	*nodemask;
 };
 
+struct mem_cgroup_zone {
+	struct mem_cgroup *mem_cgroup;
+	struct zone *zone;
+};
+
 #define lru_to_page(_head) (list_entry((_head)->prev, struct page, lru))
 
 #ifdef ARCH_HAS_PREFETCH
@@ -155,12 +163,12 @@ static DECLARE_RWSEM(shrinker_rwsem);
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR
 static bool global_reclaim(struct scan_control *sc)
 {
-	return !sc->mem_cgroup;
+	return !sc->target_mem_cgroup;
 }
 
-static bool scanning_global_lru(struct scan_control *sc)
+static bool scanning_global_lru(struct mem_cgroup_zone *mz)
 {
-	return !sc->mem_cgroup;
+	return !mz->mem_cgroup;
 }
 #else
 static bool global_reclaim(struct scan_control *sc)
@@ -168,29 +176,30 @@ static bool global_reclaim(struct scan_control *sc)
 	return true;
 }
 
-static bool scanning_global_lru(struct scan_control *sc)
+static bool scanning_global_lru(struct mem_cgroup_zone *mz)
 {
 	return true;
 }
 #endif
 
-static struct zone_reclaim_stat *get_reclaim_stat(struct zone *zone,
-						  struct scan_control *sc)
+static struct zone_reclaim_stat *get_reclaim_stat(struct mem_cgroup_zone *mz)
 {
-	if (!scanning_global_lru(sc))
-		return mem_cgroup_get_reclaim_stat(sc->mem_cgroup, zone);
+	if (!scanning_global_lru(mz))
+		return mem_cgroup_get_reclaim_stat(mz->mem_cgroup, mz->zone);
 
-	return &zone->reclaim_stat;
+	return &mz->zone->reclaim_stat;
 }
 
-static unsigned long zone_nr_lru_pages(struct zone *zone,
-				struct scan_control *sc, enum lru_list lru)
+static unsigned long zone_nr_lru_pages(struct mem_cgroup_zone *mz,
+				       enum lru_list lru)
 {
-	if (!scanning_global_lru(sc))
-		return mem_cgroup_zone_nr_lru_pages(sc->mem_cgroup,
-				zone_to_nid(zone), zone_idx(zone), BIT(lru));
+	if (!scanning_global_lru(mz))
+		return mem_cgroup_zone_nr_lru_pages(mz->mem_cgroup,
+						    zone_to_nid(mz->zone),
+						    zone_idx(mz->zone),
+						    BIT(lru));
 
-	return zone_page_state(zone, NR_LRU_BASE + lru);
+	return zone_page_state(mz->zone, NR_LRU_BASE + lru);
 }
 
 
@@ -693,12 +702,13 @@ enum page_references {
 };
 
 static enum page_references page_check_references(struct page *page,
+						  struct mem_cgroup_zone *mz,
 						  struct scan_control *sc)
 {
 	int referenced_ptes, referenced_page;
 	unsigned long vm_flags;
 
-	referenced_ptes = page_referenced(page, 1, sc->mem_cgroup, &vm_flags);
+	referenced_ptes = page_referenced(page, 1, mz->mem_cgroup, &vm_flags);
 	referenced_page = TestClearPageReferenced(page);
 
 	/* Lumpy reclaim - ignore references */
@@ -766,7 +776,7 @@ static noinline_for_stack void free_page_list(struct list_head *free_pages)
  * shrink_page_list() returns the number of reclaimed pages
  */
 static unsigned long shrink_page_list(struct list_head *page_list,
-				      struct zone *zone,
+				      struct mem_cgroup_zone *mz,
 				      struct scan_control *sc,
 				      int priority,
 				      unsigned long *ret_nr_dirty,
@@ -797,7 +807,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 			goto keep;
 
 		VM_BUG_ON(PageActive(page));
-		VM_BUG_ON(page_zone(page) != zone);
+		VM_BUG_ON(page_zone(page) != mz->zone);
 
 		sc->nr_scanned++;
 
@@ -831,7 +841,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 			}
 		}
 
-		references = page_check_references(page, sc);
+		references = page_check_references(page, mz, sc);
 		switch (references) {
 		case PAGEREF_ACTIVATE:
 			goto activate_locked;
@@ -1023,7 +1033,7 @@ keep_lumpy:
 	 * will encounter the same problem
 	 */
 	if (nr_dirty && nr_dirty == nr_congested && global_reclaim(sc))
-		zone_set_flag(zone, ZONE_CONGESTED);
+		zone_set_flag(mz->zone, ZONE_CONGESTED);
 
 	free_page_list(&free_pages);
 
@@ -1359,13 +1369,14 @@ static int too_many_isolated(struct zone *zone, int file,
  * TODO: Try merging with migrations version of putback_lru_pages
  */
 static noinline_for_stack void
-putback_lru_pages(struct zone *zone, struct scan_control *sc,
-				unsigned long nr_anon, unsigned long nr_file,
-				struct list_head *page_list)
+putback_lru_pages(struct mem_cgroup_zone *mz, struct scan_control *sc,
+		  unsigned long nr_anon, unsigned long nr_file,
+		  struct list_head *page_list)
 {
 	struct page *page;
 	struct pagevec pvec;
-	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
+	struct zone *zone = mz->zone;
+	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(mz);
 
 	pagevec_init(&pvec, 1);
 
@@ -1405,15 +1416,17 @@ putback_lru_pages(struct zone *zone, struct scan_control *sc,
 	pagevec_release(&pvec);
 }
 
-static noinline_for_stack void update_isolated_counts(struct zone *zone,
-					struct scan_control *sc,
-					unsigned long *nr_anon,
-					unsigned long *nr_file,
-					struct list_head *isolated_list)
+static noinline_for_stack void
+update_isolated_counts(struct mem_cgroup_zone *mz,
+		       struct scan_control *sc,
+		       unsigned long *nr_anon,
+		       unsigned long *nr_file,
+		       struct list_head *isolated_list)
 {
 	unsigned long nr_active;
+	struct zone *zone = mz->zone;
 	unsigned int count[NR_LRU_LISTS] = { 0, };
-	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
+	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(mz);
 
 	nr_active = clear_active_flags(isolated_list, count);
 	__count_vm_events(PGDEACTIVATE, nr_active);
@@ -1482,8 +1495,8 @@ static inline bool should_reclaim_stall(unsigned long nr_taken,
  * of reclaimed pages
  */
 static noinline_for_stack unsigned long
-shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
-			struct scan_control *sc, int priority, int file)
+shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz,
+		     struct scan_control *sc, int priority, int file)
 {
 	LIST_HEAD(page_list);
 	unsigned long nr_scanned;
@@ -1494,6 +1507,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
 	unsigned long nr_dirty = 0;
 	unsigned long nr_writeback = 0;
 	isolate_mode_t reclaim_mode = ISOLATE_INACTIVE;
+	struct zone *zone = mz->zone;
 
 	while (unlikely(too_many_isolated(zone, file, sc))) {
 		congestion_wait(BLK_RW_ASYNC, HZ/10);
@@ -1516,13 +1530,13 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
 
 	spin_lock_irq(&zone->lru_lock);
 
-	if (scanning_global_lru(sc)) {
+	if (scanning_global_lru(mz)) {
 		nr_taken = isolate_pages_global(nr_to_scan, &page_list,
 			&nr_scanned, sc->order, reclaim_mode, zone, 0, file);
 	} else {
 		nr_taken = mem_cgroup_isolate_pages(nr_to_scan, &page_list,
 			&nr_scanned, sc->order, reclaim_mode, zone,
-			sc->mem_cgroup, 0, file);
+			mz->mem_cgroup, 0, file);
 	}
 	if (global_reclaim(sc)) {
 		zone->pages_scanned += nr_scanned;
@@ -1539,17 +1553,17 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
 		return 0;
 	}
 
-	update_isolated_counts(zone, sc, &nr_anon, &nr_file, &page_list);
+	update_isolated_counts(mz, sc, &nr_anon, &nr_file, &page_list);
 
 	spin_unlock_irq(&zone->lru_lock);
 
-	nr_reclaimed = shrink_page_list(&page_list, zone, sc, priority,
+	nr_reclaimed = shrink_page_list(&page_list, mz, sc, priority,
 						&nr_dirty, &nr_writeback);
 
 	/* Check if we should syncronously wait for writeback */
 	if (should_reclaim_stall(nr_taken, nr_reclaimed, priority, sc)) {
 		set_reclaim_mode(priority, sc, true);
-		nr_reclaimed += shrink_page_list(&page_list, zone, sc,
+		nr_reclaimed += shrink_page_list(&page_list, mz, sc,
 					priority, &nr_dirty, &nr_writeback);
 	}
 
@@ -1558,7 +1572,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
 		__count_vm_events(KSWAPD_STEAL, nr_reclaimed);
 	__count_zone_vm_events(PGSTEAL, zone, nr_reclaimed);
 
-	putback_lru_pages(zone, sc, nr_anon, nr_file, &page_list);
+	putback_lru_pages(mz, sc, nr_anon, nr_file, &page_list);
 
 	/*
 	 * If reclaim is isolating dirty pages under writeback, it implies
@@ -1645,8 +1659,10 @@ static void move_active_pages_to_lru(struct zone *zone,
 		__count_vm_events(PGDEACTIVATE, pgmoved);
 }
 
-static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
-			struct scan_control *sc, int priority, int file)
+static void shrink_active_list(unsigned long nr_pages,
+			       struct mem_cgroup_zone *mz,
+			       struct scan_control *sc,
+			       int priority, int file)
 {
 	unsigned long nr_taken;
 	unsigned long pgscanned;
@@ -1655,9 +1671,10 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 	LIST_HEAD(l_active);
 	LIST_HEAD(l_inactive);
 	struct page *page;
-	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
+	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(mz);
 	unsigned long nr_rotated = 0;
 	isolate_mode_t reclaim_mode = ISOLATE_ACTIVE;
+	struct zone *zone = mz->zone;
 
 	lru_add_drain();
 
@@ -1667,7 +1684,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 		reclaim_mode |= ISOLATE_CLEAN;
 
 	spin_lock_irq(&zone->lru_lock);
-	if (scanning_global_lru(sc)) {
+	if (scanning_global_lru(mz)) {
 		nr_taken = isolate_pages_global(nr_pages, &l_hold,
 						&pgscanned, sc->order,
 						reclaim_mode, zone,
@@ -1676,7 +1693,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 		nr_taken = mem_cgroup_isolate_pages(nr_pages, &l_hold,
 						&pgscanned, sc->order,
 						reclaim_mode, zone,
-						sc->mem_cgroup, 1, file);
+						mz->mem_cgroup, 1, file);
 	}
 
 	if (global_reclaim(sc))
@@ -1702,7 +1719,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 			continue;
 		}
 
-		if (page_referenced(page, 0, sc->mem_cgroup, &vm_flags)) {
+		if (page_referenced(page, 0, mz->mem_cgroup, &vm_flags)) {
 			nr_rotated += hpage_nr_pages(page);
 			/*
 			 * Identify referenced, file-backed active pages and
@@ -1765,10 +1782,8 @@ static int inactive_anon_is_low_global(struct zone *zone)
  * Returns true if the zone does not have enough inactive anon pages,
  * meaning some active anon pages need to be deactivated.
  */
-static int inactive_anon_is_low(struct zone *zone, struct scan_control *sc)
+static int inactive_anon_is_low(struct mem_cgroup_zone *mz)
 {
-	int low;
-
 	/*
 	 * If we don't have swap space, anonymous page deactivation
 	 * is pointless.
@@ -1776,15 +1791,14 @@ static int inactive_anon_is_low(struct zone *zone, struct scan_control *sc)
 	if (!total_swap_pages)
 		return 0;
 
-	if (scanning_global_lru(sc))
-		low = inactive_anon_is_low_global(zone);
-	else
-		low = mem_cgroup_inactive_anon_is_low(sc->mem_cgroup, zone);
-	return low;
+	if (!scanning_global_lru(mz))
+		return mem_cgroup_inactive_anon_is_low(mz->mem_cgroup,
+						       mz->zone);
+
+	return inactive_anon_is_low_global(mz->zone);
 }
 #else
-static inline int inactive_anon_is_low(struct zone *zone,
-					struct scan_control *sc)
+static inline int inactive_anon_is_low(struct mem_cgroup_zone *mz)
 {
 	return 0;
 }
@@ -1802,8 +1816,7 @@ static int inactive_file_is_low_global(struct zone *zone)
 
 /**
  * inactive_file_is_low - check if file pages need to be deactivated
- * @zone: zone to check
- * @sc:   scan control of this context
+ * @mz: memory cgroup and zone to check
  *
  * When the system is doing streaming IO, memory pressure here
  * ensures that active file pages get deactivated, until more
@@ -1815,45 +1828,44 @@ static int inactive_file_is_low_global(struct zone *zone)
  * This uses a different ratio than the anonymous pages, because
  * the page cache uses a use-once replacement algorithm.
  */
-static int inactive_file_is_low(struct zone *zone, struct scan_control *sc)
+static int inactive_file_is_low(struct mem_cgroup_zone *mz)
 {
-	int low;
+	if (!scanning_global_lru(mz))
+		return mem_cgroup_inactive_file_is_low(mz->mem_cgroup,
+						       mz->zone);
 
-	if (scanning_global_lru(sc))
-		low = inactive_file_is_low_global(zone);
-	else
-		low = mem_cgroup_inactive_file_is_low(sc->mem_cgroup, zone);
-	return low;
+	return inactive_file_is_low_global(mz->zone);
 }
 
-static int inactive_list_is_low(struct zone *zone, struct scan_control *sc,
-				int file)
+static int inactive_list_is_low(struct mem_cgroup_zone *mz, int file)
 {
 	if (file)
-		return inactive_file_is_low(zone, sc);
+		return inactive_file_is_low(mz);
 	else
-		return inactive_anon_is_low(zone, sc);
+		return inactive_anon_is_low(mz);
 }
 
 static unsigned long shrink_list(enum lru_list lru, unsigned long nr_to_scan,
-	struct zone *zone, struct scan_control *sc, int priority)
+				 struct mem_cgroup_zone *mz,
+				 struct scan_control *sc, int priority)
 {
 	int file = is_file_lru(lru);
 
 	if (is_active_lru(lru)) {
-		if (inactive_list_is_low(zone, sc, file))
-		    shrink_active_list(nr_to_scan, zone, sc, priority, file);
+		if (inactive_list_is_low(mz, file))
+		    shrink_active_list(nr_to_scan, mz, sc, priority, file);
 		return 0;
 	}
 
-	return shrink_inactive_list(nr_to_scan, zone, sc, priority, file);
+	return shrink_inactive_list(nr_to_scan, mz, sc, priority, file);
 }
 
-static int vmscan_swappiness(struct scan_control *sc)
+static int vmscan_swappiness(struct mem_cgroup_zone *mz,
+			     struct scan_control *sc)
 {
 	if (global_reclaim(sc))
 		return vm_swappiness;
-	return mem_cgroup_swappiness(sc->mem_cgroup);
+	return mem_cgroup_swappiness(mz->mem_cgroup);
 }
 
 /*
@@ -1864,13 +1876,13 @@ static int vmscan_swappiness(struct scan_control *sc)
  *
  * nr[0] = anon pages to scan; nr[1] = file pages to scan
  */
-static void get_scan_count(struct zone *zone, struct scan_control *sc,
-					unsigned long *nr, int priority)
+static void get_scan_count(struct mem_cgroup_zone *mz, struct scan_control *sc,
+			   unsigned long *nr, int priority)
 {
 	unsigned long anon, file, free;
 	unsigned long anon_prio, file_prio;
 	unsigned long ap, fp;
-	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
+	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(mz);
 	u64 fraction[2], denominator;
 	enum lru_list l;
 	int noswap = 0;
@@ -1900,16 +1912,16 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
 		goto out;
 	}
 
-	anon  = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_ANON) +
-		zone_nr_lru_pages(zone, sc, LRU_INACTIVE_ANON);
-	file  = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_FILE) +
-		zone_nr_lru_pages(zone, sc, LRU_INACTIVE_FILE);
+	anon  = zone_nr_lru_pages(mz, LRU_ACTIVE_ANON) +
+		zone_nr_lru_pages(mz, LRU_INACTIVE_ANON);
+	file  = zone_nr_lru_pages(mz, LRU_ACTIVE_FILE) +
+		zone_nr_lru_pages(mz, LRU_INACTIVE_FILE);
 
 	if (global_reclaim(sc)) {
-		free  = zone_page_state(zone, NR_FREE_PAGES);
+		free  = zone_page_state(mz->zone, NR_FREE_PAGES);
 		/* If we have very few page cache pages,
 		   force-scan anon pages. */
-		if (unlikely(file + free <= high_wmark_pages(zone))) {
+		if (unlikely(file + free <= high_wmark_pages(mz->zone))) {
 			fraction[0] = 1;
 			fraction[1] = 0;
 			denominator = 1;
@@ -1921,8 +1933,8 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
 	 * With swappiness at 100, anonymous and file have the same priority.
 	 * This scanning priority is essentially the inverse of IO cost.
 	 */
-	anon_prio = vmscan_swappiness(sc);
-	file_prio = 200 - vmscan_swappiness(sc);
+	anon_prio = vmscan_swappiness(mz, sc);
+	file_prio = 200 - vmscan_swappiness(mz, sc);
 
 	/*
 	 * OK, so we have swap space and a fair amount of page cache
@@ -1935,7 +1947,7 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
 	 *
 	 * anon in [0], file in [1]
 	 */
-	spin_lock_irq(&zone->lru_lock);
+	spin_lock_irq(&mz->zone->lru_lock);
 	if (unlikely(reclaim_stat->recent_scanned[0] > anon / 4)) {
 		reclaim_stat->recent_scanned[0] /= 2;
 		reclaim_stat->recent_rotated[0] /= 2;
@@ -1956,7 +1968,7 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
 
 	fp = (file_prio + 1) * (reclaim_stat->recent_scanned[1] + 1);
 	fp /= reclaim_stat->recent_rotated[1] + 1;
-	spin_unlock_irq(&zone->lru_lock);
+	spin_unlock_irq(&mz->zone->lru_lock);
 
 	fraction[0] = ap;
 	fraction[1] = fp;
@@ -1966,7 +1978,7 @@ out:
 		int file = is_file_lru(l);
 		unsigned long scan;
 
-		scan = zone_nr_lru_pages(zone, sc, l);
+		scan = zone_nr_lru_pages(mz, l);
 		if (priority || noswap) {
 			scan >>= priority;
 			if (!scan && force_scan)
@@ -1984,7 +1996,7 @@ out:
  * back to the allocator and call try_to_compact_zone(), we ensure that
  * there are enough free pages for it to be likely successful
  */
-static inline bool should_continue_reclaim(struct zone *zone,
+static inline bool should_continue_reclaim(struct mem_cgroup_zone *mz,
 					unsigned long nr_reclaimed,
 					unsigned long nr_scanned,
 					struct scan_control *sc)
@@ -2024,14 +2036,14 @@ static inline bool should_continue_reclaim(struct zone *zone,
 	 * inactive lists are large enough, continue reclaiming
 	 */
 	pages_for_compaction = (2UL << sc->order);
-	inactive_lru_pages = zone_nr_lru_pages(zone, sc, LRU_INACTIVE_ANON) +
-				zone_nr_lru_pages(zone, sc, LRU_INACTIVE_FILE);
+	inactive_lru_pages = zone_nr_lru_pages(mz, LRU_INACTIVE_ANON) +
+				zone_nr_lru_pages(mz, LRU_INACTIVE_FILE);
 	if (sc->nr_reclaimed < pages_for_compaction &&
 			inactive_lru_pages > pages_for_compaction)
 		return true;
 
 	/* If compaction would go ahead or the allocation would succeed, stop */
-	switch (compaction_suitable(zone, sc->order)) {
+	switch (compaction_suitable(mz->zone, sc->order)) {
 	case COMPACT_PARTIAL:
 	case COMPACT_CONTINUE:
 		return false;
@@ -2043,8 +2055,8 @@ static inline bool should_continue_reclaim(struct zone *zone,
 /*
  * This is a basic per-zone page freer.  Used by both kswapd and direct reclaim.
  */
-static void shrink_zone(int priority, struct zone *zone,
-				struct scan_control *sc)
+static void shrink_mem_cgroup_zone(int priority, struct mem_cgroup_zone *mz,
+				   struct scan_control *sc)
 {
 	unsigned long nr[NR_LRU_LISTS];
 	unsigned long nr_to_scan;
@@ -2056,7 +2068,7 @@ static void shrink_zone(int priority, struct zone *zone,
 restart:
 	nr_reclaimed = 0;
 	nr_scanned = sc->nr_scanned;
-	get_scan_count(zone, sc, nr, priority);
+	get_scan_count(mz, sc, nr, priority);
 
 	blk_start_plug(&plug);
 	while (nr[LRU_INACTIVE_ANON] || nr[LRU_ACTIVE_FILE] ||
@@ -2068,7 +2080,7 @@ restart:
 				nr[l] -= nr_to_scan;
 
 				nr_reclaimed += shrink_list(l, nr_to_scan,
-							    zone, sc, priority);
+							    mz, sc, priority);
 			}
 		}
 		/*
@@ -2089,17 +2101,28 @@ restart:
 	 * Even if we did not try to evict anon pages at all, we want to
 	 * rebalance the anon lru active/inactive ratio.
 	 */
-	if (inactive_anon_is_low(zone, sc))
-		shrink_active_list(SWAP_CLUSTER_MAX, zone, sc, priority, 0);
+	if (inactive_anon_is_low(mz))
+		shrink_active_list(SWAP_CLUSTER_MAX, mz, sc, priority, 0);
 
 	/* reclaim/compaction might need reclaim to continue */
-	if (should_continue_reclaim(zone, nr_reclaimed,
+	if (should_continue_reclaim(mz, nr_reclaimed,
 					sc->nr_scanned - nr_scanned, sc))
 		goto restart;
 
 	throttle_vm_writeout(sc->gfp_mask);
 }
 
+static void shrink_zone(int priority, struct zone *zone,
+			struct scan_control *sc)
+{
+	struct mem_cgroup_zone mz = {
+		.mem_cgroup = sc->target_mem_cgroup,
+		.zone = zone,
+	};
+
+	shrink_mem_cgroup_zone(priority, &mz, sc);
+}
+
 /*
  * This is the direct reclaim path, for page-allocating processes.  We only
  * try to reclaim pages from zones which will satisfy the caller's allocation
@@ -2241,7 +2264,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
 	for (priority = DEF_PRIORITY; priority >= 0; priority--) {
 		sc->nr_scanned = 0;
 		if (!priority)
-			disable_swap_token(sc->mem_cgroup);
+			disable_swap_token(sc->target_mem_cgroup);
 		if (shrink_zones(priority, zonelist, sc))
 			break;
 
@@ -2328,7 +2351,7 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
 		.may_unmap = 1,
 		.may_swap = 1,
 		.order = order,
-		.mem_cgroup = NULL,
+		.target_mem_cgroup = NULL,
 		.nodemask = nodemask,
 	};
 	struct shrink_control shrink = {
@@ -2360,7 +2383,7 @@ unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
 		.may_unmap = 1,
 		.may_swap = !noswap,
 		.order = 0,
-		.mem_cgroup = mem,
+		.target_mem_cgroup = mem,
 	};
 
 	sc.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) |
@@ -2398,7 +2421,7 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
 		.may_swap = !noswap,
 		.nr_to_reclaim = SWAP_CLUSTER_MAX,
 		.order = 0,
-		.mem_cgroup = mem_cont,
+		.target_mem_cgroup = mem_cont,
 		.nodemask = NULL, /* we don't care the placement */
 		.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) |
 				(GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK),
@@ -2428,6 +2451,18 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
 }
 #endif
 
+static void age_active_anon(struct zone *zone, struct scan_control *sc,
+			    int priority)
+{
+	struct mem_cgroup_zone mz = {
+		.mem_cgroup = NULL,
+		.zone = zone,
+	};
+
+	if (inactive_anon_is_low(&mz))
+		shrink_active_list(SWAP_CLUSTER_MAX, &mz, sc, priority, 0);
+}
+
 /*
  * pgdat_balanced is used when checking if a node is balanced for high-order
  * allocations. Only zones that meet watermarks and are in a zone allowed
@@ -2548,7 +2583,7 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
 		 */
 		.nr_to_reclaim = ULONG_MAX,
 		.order = order,
-		.mem_cgroup = NULL,
+		.target_mem_cgroup = NULL,
 	};
 	struct shrink_control shrink = {
 		.gfp_mask = sc.gfp_mask,
@@ -2587,9 +2622,7 @@ loop_again:
 			 * Do some background aging of the anon list, to give
 			 * pages a chance to be referenced before reclaiming.
 			 */
-			if (inactive_anon_is_low(zone, &sc))
-				shrink_active_list(SWAP_CLUSTER_MAX, zone,
-							&sc, priority, 0);
+			age_active_anon(zone, &sc, priority);
 
 			if (!zone_watermark_ok_safe(zone, order,
 					high_wmark_pages(zone), 0, 0)) {
-- 
1.7.6.4


^ permalink raw reply related	[flat|nested] 32+ messages in thread
* [patch 03/10] mm: vmscan: distinguish between memcg triggering reclaim and memcg being scanned
@ 2011-11-08 21:23   ` Johannes Weiner
  0 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-11-08 21:23 UTC (permalink / raw)
  To: Andrew Morton
  Cc: KAMEZAWA Hiroyuki, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel

Memory cgroup hierarchies are currently handled completely outside of
the traditional reclaim code, which is invoked with a single memory
cgroup as an argument for the whole call stack.

Subsequent patches will switch this code to do hierarchical reclaim,
so there needs to be a distinction between a) the memory cgroup that
is triggering reclaim due to hitting its limit and b) the memory
cgroup that is being scanned as a child of a).

This patch introduces a struct mem_cgroup_zone that contains the
combination of the memory cgroup and the zone being scanned, which is
then passed down the stack instead of the zone argument.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
---
 mm/vmscan.c |  249 +++++++++++++++++++++++++++++++++--------------------------
 1 files changed, 141 insertions(+), 108 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 189597e..b8e22a9 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -103,8 +103,11 @@ struct scan_control {
 	 */
 	reclaim_mode_t reclaim_mode;
 
-	/* Which cgroup do we reclaim from */
-	struct mem_cgroup *mem_cgroup;
+	/*
+	 * The memory cgroup that hit its limit and as a result is the
+	 * primary target of this reclaim invocation.
+	 */
+	struct mem_cgroup *target_mem_cgroup;
 
 	/*
 	 * Nodemask of nodes allowed by the caller. If NULL, all nodes
@@ -113,6 +116,11 @@ struct scan_control {
 	nodemask_t	*nodemask;
 };
 
+struct mem_cgroup_zone {
+	struct mem_cgroup *mem_cgroup;
+	struct zone *zone;
+};
+
 #define lru_to_page(_head) (list_entry((_head)->prev, struct page, lru))
 
 #ifdef ARCH_HAS_PREFETCH
@@ -155,12 +163,12 @@ static DECLARE_RWSEM(shrinker_rwsem);
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR
 static bool global_reclaim(struct scan_control *sc)
 {
-	return !sc->mem_cgroup;
+	return !sc->target_mem_cgroup;
 }
 
-static bool scanning_global_lru(struct scan_control *sc)
+static bool scanning_global_lru(struct mem_cgroup_zone *mz)
 {
-	return !sc->mem_cgroup;
+	return !mz->mem_cgroup;
 }
 #else
 static bool global_reclaim(struct scan_control *sc)
@@ -168,29 +176,30 @@ static bool global_reclaim(struct scan_control *sc)
 	return true;
 }
 
-static bool scanning_global_lru(struct scan_control *sc)
+static bool scanning_global_lru(struct mem_cgroup_zone *mz)
 {
 	return true;
 }
 #endif
 
-static struct zone_reclaim_stat *get_reclaim_stat(struct zone *zone,
-						  struct scan_control *sc)
+static struct zone_reclaim_stat *get_reclaim_stat(struct mem_cgroup_zone *mz)
 {
-	if (!scanning_global_lru(sc))
-		return mem_cgroup_get_reclaim_stat(sc->mem_cgroup, zone);
+	if (!scanning_global_lru(mz))
+		return mem_cgroup_get_reclaim_stat(mz->mem_cgroup, mz->zone);
 
-	return &zone->reclaim_stat;
+	return &mz->zone->reclaim_stat;
 }
 
-static unsigned long zone_nr_lru_pages(struct zone *zone,
-				struct scan_control *sc, enum lru_list lru)
+static unsigned long zone_nr_lru_pages(struct mem_cgroup_zone *mz,
+				       enum lru_list lru)
 {
-	if (!scanning_global_lru(sc))
-		return mem_cgroup_zone_nr_lru_pages(sc->mem_cgroup,
-				zone_to_nid(zone), zone_idx(zone), BIT(lru));
+	if (!scanning_global_lru(mz))
+		return mem_cgroup_zone_nr_lru_pages(mz->mem_cgroup,
+						    zone_to_nid(mz->zone),
+						    zone_idx(mz->zone),
+						    BIT(lru));
 
-	return zone_page_state(zone, NR_LRU_BASE + lru);
+	return zone_page_state(mz->zone, NR_LRU_BASE + lru);
 }
 
 
@@ -693,12 +702,13 @@ enum page_references {
 };
 
 static enum page_references page_check_references(struct page *page,
+						  struct mem_cgroup_zone *mz,
 						  struct scan_control *sc)
 {
 	int referenced_ptes, referenced_page;
 	unsigned long vm_flags;
 
-	referenced_ptes = page_referenced(page, 1, sc->mem_cgroup, &vm_flags);
+	referenced_ptes = page_referenced(page, 1, mz->mem_cgroup, &vm_flags);
 	referenced_page = TestClearPageReferenced(page);
 
 	/* Lumpy reclaim - ignore references */
@@ -766,7 +776,7 @@ static noinline_for_stack void free_page_list(struct list_head *free_pages)
  * shrink_page_list() returns the number of reclaimed pages
  */
 static unsigned long shrink_page_list(struct list_head *page_list,
-				      struct zone *zone,
+				      struct mem_cgroup_zone *mz,
 				      struct scan_control *sc,
 				      int priority,
 				      unsigned long *ret_nr_dirty,
@@ -797,7 +807,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 			goto keep;
 
 		VM_BUG_ON(PageActive(page));
-		VM_BUG_ON(page_zone(page) != zone);
+		VM_BUG_ON(page_zone(page) != mz->zone);
 
 		sc->nr_scanned++;
 
@@ -831,7 +841,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 			}
 		}
 
-		references = page_check_references(page, sc);
+		references = page_check_references(page, mz, sc);
 		switch (references) {
 		case PAGEREF_ACTIVATE:
 			goto activate_locked;
@@ -1023,7 +1033,7 @@ keep_lumpy:
 	 * will encounter the same problem
 	 */
 	if (nr_dirty && nr_dirty == nr_congested && global_reclaim(sc))
-		zone_set_flag(zone, ZONE_CONGESTED);
+		zone_set_flag(mz->zone, ZONE_CONGESTED);
 
 	free_page_list(&free_pages);
 
@@ -1359,13 +1369,14 @@ static int too_many_isolated(struct zone *zone, int file,
  * TODO: Try merging with migrations version of putback_lru_pages
  */
 static noinline_for_stack void
-putback_lru_pages(struct zone *zone, struct scan_control *sc,
-				unsigned long nr_anon, unsigned long nr_file,
-				struct list_head *page_list)
+putback_lru_pages(struct mem_cgroup_zone *mz, struct scan_control *sc,
+		  unsigned long nr_anon, unsigned long nr_file,
+		  struct list_head *page_list)
 {
 	struct page *page;
 	struct pagevec pvec;
-	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
+	struct zone *zone = mz->zone;
+	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(mz);
 
 	pagevec_init(&pvec, 1);
 
@@ -1405,15 +1416,17 @@ putback_lru_pages(struct zone *zone, struct scan_control *sc,
 	pagevec_release(&pvec);
 }
 
-static noinline_for_stack void update_isolated_counts(struct zone *zone,
-					struct scan_control *sc,
-					unsigned long *nr_anon,
-					unsigned long *nr_file,
-					struct list_head *isolated_list)
+static noinline_for_stack void
+update_isolated_counts(struct mem_cgroup_zone *mz,
+		       struct scan_control *sc,
+		       unsigned long *nr_anon,
+		       unsigned long *nr_file,
+		       struct list_head *isolated_list)
 {
 	unsigned long nr_active;
+	struct zone *zone = mz->zone;
 	unsigned int count[NR_LRU_LISTS] = { 0, };
-	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
+	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(mz);
 
 	nr_active = clear_active_flags(isolated_list, count);
 	__count_vm_events(PGDEACTIVATE, nr_active);
@@ -1482,8 +1495,8 @@ static inline bool should_reclaim_stall(unsigned long nr_taken,
  * of reclaimed pages
  */
 static noinline_for_stack unsigned long
-shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
-			struct scan_control *sc, int priority, int file)
+shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz,
+		     struct scan_control *sc, int priority, int file)
 {
 	LIST_HEAD(page_list);
 	unsigned long nr_scanned;
@@ -1494,6 +1507,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
 	unsigned long nr_dirty = 0;
 	unsigned long nr_writeback = 0;
 	isolate_mode_t reclaim_mode = ISOLATE_INACTIVE;
+	struct zone *zone = mz->zone;
 
 	while (unlikely(too_many_isolated(zone, file, sc))) {
 		congestion_wait(BLK_RW_ASYNC, HZ/10);
@@ -1516,13 +1530,13 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
 
 	spin_lock_irq(&zone->lru_lock);
 
-	if (scanning_global_lru(sc)) {
+	if (scanning_global_lru(mz)) {
 		nr_taken = isolate_pages_global(nr_to_scan, &page_list,
 			&nr_scanned, sc->order, reclaim_mode, zone, 0, file);
 	} else {
 		nr_taken = mem_cgroup_isolate_pages(nr_to_scan, &page_list,
 			&nr_scanned, sc->order, reclaim_mode, zone,
-			sc->mem_cgroup, 0, file);
+			mz->mem_cgroup, 0, file);
 	}
 	if (global_reclaim(sc)) {
 		zone->pages_scanned += nr_scanned;
@@ -1539,17 +1553,17 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
 		return 0;
 	}
 
-	update_isolated_counts(zone, sc, &nr_anon, &nr_file, &page_list);
+	update_isolated_counts(mz, sc, &nr_anon, &nr_file, &page_list);
 
 	spin_unlock_irq(&zone->lru_lock);
 
-	nr_reclaimed = shrink_page_list(&page_list, zone, sc, priority,
+	nr_reclaimed = shrink_page_list(&page_list, mz, sc, priority,
 						&nr_dirty, &nr_writeback);
 
 	/* Check if we should syncronously wait for writeback */
 	if (should_reclaim_stall(nr_taken, nr_reclaimed, priority, sc)) {
 		set_reclaim_mode(priority, sc, true);
-		nr_reclaimed += shrink_page_list(&page_list, zone, sc,
+		nr_reclaimed += shrink_page_list(&page_list, mz, sc,
 					priority, &nr_dirty, &nr_writeback);
 	}
 
@@ -1558,7 +1572,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
 		__count_vm_events(KSWAPD_STEAL, nr_reclaimed);
 	__count_zone_vm_events(PGSTEAL, zone, nr_reclaimed);
 
-	putback_lru_pages(zone, sc, nr_anon, nr_file, &page_list);
+	putback_lru_pages(mz, sc, nr_anon, nr_file, &page_list);
 
 	/*
 	 * If reclaim is isolating dirty pages under writeback, it implies
@@ -1645,8 +1659,10 @@ static void move_active_pages_to_lru(struct zone *zone,
 		__count_vm_events(PGDEACTIVATE, pgmoved);
 }
 
-static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
-			struct scan_control *sc, int priority, int file)
+static void shrink_active_list(unsigned long nr_pages,
+			       struct mem_cgroup_zone *mz,
+			       struct scan_control *sc,
+			       int priority, int file)
 {
 	unsigned long nr_taken;
 	unsigned long pgscanned;
@@ -1655,9 +1671,10 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 	LIST_HEAD(l_active);
 	LIST_HEAD(l_inactive);
 	struct page *page;
-	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
+	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(mz);
 	unsigned long nr_rotated = 0;
 	isolate_mode_t reclaim_mode = ISOLATE_ACTIVE;
+	struct zone *zone = mz->zone;
 
 	lru_add_drain();
 
@@ -1667,7 +1684,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 		reclaim_mode |= ISOLATE_CLEAN;
 
 	spin_lock_irq(&zone->lru_lock);
-	if (scanning_global_lru(sc)) {
+	if (scanning_global_lru(mz)) {
 		nr_taken = isolate_pages_global(nr_pages, &l_hold,
 						&pgscanned, sc->order,
 						reclaim_mode, zone,
@@ -1676,7 +1693,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 		nr_taken = mem_cgroup_isolate_pages(nr_pages, &l_hold,
 						&pgscanned, sc->order,
 						reclaim_mode, zone,
-						sc->mem_cgroup, 1, file);
+						mz->mem_cgroup, 1, file);
 	}
 
 	if (global_reclaim(sc))
@@ -1702,7 +1719,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 			continue;
 		}
 
-		if (page_referenced(page, 0, sc->mem_cgroup, &vm_flags)) {
+		if (page_referenced(page, 0, mz->mem_cgroup, &vm_flags)) {
 			nr_rotated += hpage_nr_pages(page);
 			/*
 			 * Identify referenced, file-backed active pages and
@@ -1765,10 +1782,8 @@ static int inactive_anon_is_low_global(struct zone *zone)
  * Returns true if the zone does not have enough inactive anon pages,
  * meaning some active anon pages need to be deactivated.
  */
-static int inactive_anon_is_low(struct zone *zone, struct scan_control *sc)
+static int inactive_anon_is_low(struct mem_cgroup_zone *mz)
 {
-	int low;
-
 	/*
 	 * If we don't have swap space, anonymous page deactivation
 	 * is pointless.
@@ -1776,15 +1791,14 @@ static int inactive_anon_is_low(struct zone *zone, struct scan_control *sc)
 	if (!total_swap_pages)
 		return 0;
 
-	if (scanning_global_lru(sc))
-		low = inactive_anon_is_low_global(zone);
-	else
-		low = mem_cgroup_inactive_anon_is_low(sc->mem_cgroup, zone);
-	return low;
+	if (!scanning_global_lru(mz))
+		return mem_cgroup_inactive_anon_is_low(mz->mem_cgroup,
+						       mz->zone);
+
+	return inactive_anon_is_low_global(mz->zone);
 }
 #else
-static inline int inactive_anon_is_low(struct zone *zone,
-					struct scan_control *sc)
+static inline int inactive_anon_is_low(struct mem_cgroup_zone *mz)
 {
 	return 0;
 }
@@ -1802,8 +1816,7 @@ static int inactive_file_is_low_global(struct zone *zone)
 
 /**
  * inactive_file_is_low - check if file pages need to be deactivated
- * @zone: zone to check
- * @sc:   scan control of this context
+ * @mz: memory cgroup and zone to check
  *
  * When the system is doing streaming IO, memory pressure here
  * ensures that active file pages get deactivated, until more
@@ -1815,45 +1828,44 @@ static int inactive_file_is_low_global(struct zone *zone)
  * This uses a different ratio than the anonymous pages, because
  * the page cache uses a use-once replacement algorithm.
  */
-static int inactive_file_is_low(struct zone *zone, struct scan_control *sc)
+static int inactive_file_is_low(struct mem_cgroup_zone *mz)
 {
-	int low;
+	if (!scanning_global_lru(mz))
+		return mem_cgroup_inactive_file_is_low(mz->mem_cgroup,
+						       mz->zone);
 
-	if (scanning_global_lru(sc))
-		low = inactive_file_is_low_global(zone);
-	else
-		low = mem_cgroup_inactive_file_is_low(sc->mem_cgroup, zone);
-	return low;
+	return inactive_file_is_low_global(mz->zone);
 }
 
-static int inactive_list_is_low(struct zone *zone, struct scan_control *sc,
-				int file)
+static int inactive_list_is_low(struct mem_cgroup_zone *mz, int file)
 {
 	if (file)
-		return inactive_file_is_low(zone, sc);
+		return inactive_file_is_low(mz);
 	else
-		return inactive_anon_is_low(zone, sc);
+		return inactive_anon_is_low(mz);
 }
 
 static unsigned long shrink_list(enum lru_list lru, unsigned long nr_to_scan,
-	struct zone *zone, struct scan_control *sc, int priority)
+				 struct mem_cgroup_zone *mz,
+				 struct scan_control *sc, int priority)
 {
 	int file = is_file_lru(lru);
 
 	if (is_active_lru(lru)) {
-		if (inactive_list_is_low(zone, sc, file))
-		    shrink_active_list(nr_to_scan, zone, sc, priority, file);
+		if (inactive_list_is_low(mz, file))
+		    shrink_active_list(nr_to_scan, mz, sc, priority, file);
 		return 0;
 	}
 
-	return shrink_inactive_list(nr_to_scan, zone, sc, priority, file);
+	return shrink_inactive_list(nr_to_scan, mz, sc, priority, file);
 }
 
-static int vmscan_swappiness(struct scan_control *sc)
+static int vmscan_swappiness(struct mem_cgroup_zone *mz,
+			     struct scan_control *sc)
 {
 	if (global_reclaim(sc))
 		return vm_swappiness;
-	return mem_cgroup_swappiness(sc->mem_cgroup);
+	return mem_cgroup_swappiness(mz->mem_cgroup);
 }
 
 /*
@@ -1864,13 +1876,13 @@ static int vmscan_swappiness(struct scan_control *sc)
  *
  * nr[0] = anon pages to scan; nr[1] = file pages to scan
  */
-static void get_scan_count(struct zone *zone, struct scan_control *sc,
-					unsigned long *nr, int priority)
+static void get_scan_count(struct mem_cgroup_zone *mz, struct scan_control *sc,
+			   unsigned long *nr, int priority)
 {
 	unsigned long anon, file, free;
 	unsigned long anon_prio, file_prio;
 	unsigned long ap, fp;
-	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
+	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(mz);
 	u64 fraction[2], denominator;
 	enum lru_list l;
 	int noswap = 0;
@@ -1900,16 +1912,16 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
 		goto out;
 	}
 
-	anon  = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_ANON) +
-		zone_nr_lru_pages(zone, sc, LRU_INACTIVE_ANON);
-	file  = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_FILE) +
-		zone_nr_lru_pages(zone, sc, LRU_INACTIVE_FILE);
+	anon  = zone_nr_lru_pages(mz, LRU_ACTIVE_ANON) +
+		zone_nr_lru_pages(mz, LRU_INACTIVE_ANON);
+	file  = zone_nr_lru_pages(mz, LRU_ACTIVE_FILE) +
+		zone_nr_lru_pages(mz, LRU_INACTIVE_FILE);
 
 	if (global_reclaim(sc)) {
-		free  = zone_page_state(zone, NR_FREE_PAGES);
+		free  = zone_page_state(mz->zone, NR_FREE_PAGES);
 		/* If we have very few page cache pages,
 		   force-scan anon pages. */
-		if (unlikely(file + free <= high_wmark_pages(zone))) {
+		if (unlikely(file + free <= high_wmark_pages(mz->zone))) {
 			fraction[0] = 1;
 			fraction[1] = 0;
 			denominator = 1;
@@ -1921,8 +1933,8 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
 	 * With swappiness at 100, anonymous and file have the same priority.
 	 * This scanning priority is essentially the inverse of IO cost.
 	 */
-	anon_prio = vmscan_swappiness(sc);
-	file_prio = 200 - vmscan_swappiness(sc);
+	anon_prio = vmscan_swappiness(mz, sc);
+	file_prio = 200 - vmscan_swappiness(mz, sc);
 
 	/*
 	 * OK, so we have swap space and a fair amount of page cache
@@ -1935,7 +1947,7 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
 	 *
 	 * anon in [0], file in [1]
 	 */
-	spin_lock_irq(&zone->lru_lock);
+	spin_lock_irq(&mz->zone->lru_lock);
 	if (unlikely(reclaim_stat->recent_scanned[0] > anon / 4)) {
 		reclaim_stat->recent_scanned[0] /= 2;
 		reclaim_stat->recent_rotated[0] /= 2;
@@ -1956,7 +1968,7 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
 
 	fp = (file_prio + 1) * (reclaim_stat->recent_scanned[1] + 1);
 	fp /= reclaim_stat->recent_rotated[1] + 1;
-	spin_unlock_irq(&zone->lru_lock);
+	spin_unlock_irq(&mz->zone->lru_lock);
 
 	fraction[0] = ap;
 	fraction[1] = fp;
@@ -1966,7 +1978,7 @@ out:
 		int file = is_file_lru(l);
 		unsigned long scan;
 
-		scan = zone_nr_lru_pages(zone, sc, l);
+		scan = zone_nr_lru_pages(mz, l);
 		if (priority || noswap) {
 			scan >>= priority;
 			if (!scan && force_scan)
@@ -1984,7 +1996,7 @@ out:
  * back to the allocator and call try_to_compact_zone(), we ensure that
  * there are enough free pages for it to be likely successful
  */
-static inline bool should_continue_reclaim(struct zone *zone,
+static inline bool should_continue_reclaim(struct mem_cgroup_zone *mz,
 					unsigned long nr_reclaimed,
 					unsigned long nr_scanned,
 					struct scan_control *sc)
@@ -2024,14 +2036,14 @@ static inline bool should_continue_reclaim(struct zone *zone,
 	 * inactive lists are large enough, continue reclaiming
 	 */
 	pages_for_compaction = (2UL << sc->order);
-	inactive_lru_pages = zone_nr_lru_pages(zone, sc, LRU_INACTIVE_ANON) +
-				zone_nr_lru_pages(zone, sc, LRU_INACTIVE_FILE);
+	inactive_lru_pages = zone_nr_lru_pages(mz, LRU_INACTIVE_ANON) +
+				zone_nr_lru_pages(mz, LRU_INACTIVE_FILE);
 	if (sc->nr_reclaimed < pages_for_compaction &&
 			inactive_lru_pages > pages_for_compaction)
 		return true;
 
 	/* If compaction would go ahead or the allocation would succeed, stop */
-	switch (compaction_suitable(zone, sc->order)) {
+	switch (compaction_suitable(mz->zone, sc->order)) {
 	case COMPACT_PARTIAL:
 	case COMPACT_CONTINUE:
 		return false;
@@ -2043,8 +2055,8 @@ static inline bool should_continue_reclaim(struct zone *zone,
 /*
  * This is a basic per-zone page freer.  Used by both kswapd and direct reclaim.
  */
-static void shrink_zone(int priority, struct zone *zone,
-				struct scan_control *sc)
+static void shrink_mem_cgroup_zone(int priority, struct mem_cgroup_zone *mz,
+				   struct scan_control *sc)
 {
 	unsigned long nr[NR_LRU_LISTS];
 	unsigned long nr_to_scan;
@@ -2056,7 +2068,7 @@ static void shrink_zone(int priority, struct zone *zone,
 restart:
 	nr_reclaimed = 0;
 	nr_scanned = sc->nr_scanned;
-	get_scan_count(zone, sc, nr, priority);
+	get_scan_count(mz, sc, nr, priority);
 
 	blk_start_plug(&plug);
 	while (nr[LRU_INACTIVE_ANON] || nr[LRU_ACTIVE_FILE] ||
@@ -2068,7 +2080,7 @@ restart:
 				nr[l] -= nr_to_scan;
 
 				nr_reclaimed += shrink_list(l, nr_to_scan,
-							    zone, sc, priority);
+							    mz, sc, priority);
 			}
 		}
 		/*
@@ -2089,17 +2101,28 @@ restart:
 	 * Even if we did not try to evict anon pages at all, we want to
 	 * rebalance the anon lru active/inactive ratio.
 	 */
-	if (inactive_anon_is_low(zone, sc))
-		shrink_active_list(SWAP_CLUSTER_MAX, zone, sc, priority, 0);
+	if (inactive_anon_is_low(mz))
+		shrink_active_list(SWAP_CLUSTER_MAX, mz, sc, priority, 0);
 
 	/* reclaim/compaction might need reclaim to continue */
-	if (should_continue_reclaim(zone, nr_reclaimed,
+	if (should_continue_reclaim(mz, nr_reclaimed,
 					sc->nr_scanned - nr_scanned, sc))
 		goto restart;
 
 	throttle_vm_writeout(sc->gfp_mask);
 }
 
+static void shrink_zone(int priority, struct zone *zone,
+			struct scan_control *sc)
+{
+	struct mem_cgroup_zone mz = {
+		.mem_cgroup = sc->target_mem_cgroup,
+		.zone = zone,
+	};
+
+	shrink_mem_cgroup_zone(priority, &mz, sc);
+}
+
 /*
  * This is the direct reclaim path, for page-allocating processes.  We only
  * try to reclaim pages from zones which will satisfy the caller's allocation
@@ -2241,7 +2264,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
 	for (priority = DEF_PRIORITY; priority >= 0; priority--) {
 		sc->nr_scanned = 0;
 		if (!priority)
-			disable_swap_token(sc->mem_cgroup);
+			disable_swap_token(sc->target_mem_cgroup);
 		if (shrink_zones(priority, zonelist, sc))
 			break;
 
@@ -2328,7 +2351,7 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
 		.may_unmap = 1,
 		.may_swap = 1,
 		.order = order,
-		.mem_cgroup = NULL,
+		.target_mem_cgroup = NULL,
 		.nodemask = nodemask,
 	};
 	struct shrink_control shrink = {
@@ -2360,7 +2383,7 @@ unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
 		.may_unmap = 1,
 		.may_swap = !noswap,
 		.order = 0,
-		.mem_cgroup = mem,
+		.target_mem_cgroup = mem,
 	};
 
 	sc.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) |
@@ -2398,7 +2421,7 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
 		.may_swap = !noswap,
 		.nr_to_reclaim = SWAP_CLUSTER_MAX,
 		.order = 0,
-		.mem_cgroup = mem_cont,
+		.target_mem_cgroup = mem_cont,
 		.nodemask = NULL, /* we don't care the placement */
 		.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) |
 				(GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK),
@@ -2428,6 +2451,18 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
 }
 #endif
 
+static void age_active_anon(struct zone *zone, struct scan_control *sc,
+			    int priority)
+{
+	struct mem_cgroup_zone mz = {
+		.mem_cgroup = NULL,
+		.zone = zone,
+	};
+
+	if (inactive_anon_is_low(&mz))
+		shrink_active_list(SWAP_CLUSTER_MAX, &mz, sc, priority, 0);
+}
+
 /*
  * pgdat_balanced is used when checking if a node is balanced for high-order
  * allocations. Only zones that meet watermarks and are in a zone allowed
@@ -2548,7 +2583,7 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
 		 */
 		.nr_to_reclaim = ULONG_MAX,
 		.order = order,
-		.mem_cgroup = NULL,
+		.target_mem_cgroup = NULL,
 	};
 	struct shrink_control shrink = {
 		.gfp_mask = sc.gfp_mask,
@@ -2587,9 +2622,7 @@ loop_again:
 			 * Do some background aging of the anon list, to give
 			 * pages a chance to be referenced before reclaiming.
 			 */
-			if (inactive_anon_is_low(zone, &sc))
-				shrink_active_list(SWAP_CLUSTER_MAX, zone,
-							&sc, priority, 0);
+			age_active_anon(zone, &sc, priority);
 
 			if (!zone_watermark_ok_safe(zone, order,
 					high_wmark_pages(zone), 0, 0)) {
-- 
1.7.6.4

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^ permalink raw reply related	[flat|nested] 32+ messages in thread
* [patch 04/10] mm: memcg: per-priority per-zone hierarchy scan generations
  2011-11-08 21:23 ` Johannes Weiner
@ 2011-11-08 21:23   ` Johannes Weiner
  -1 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-11-08 21:23 UTC (permalink / raw)
  To: Andrew Morton
  Cc: KAMEZAWA Hiroyuki, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel

Memory cgroup limit reclaim currently picks one memory cgroup out of
the target hierarchy, remembers it as the last scanned child, and
reclaims all zones in it with decreasing priority levels.

The new hierarchy reclaim code will pick memory cgroups from the same
hierarchy concurrently from different zones and priority levels, it
becomes necessary that hierarchy roots not only remember the last
scanned child, but do so for each zone and priority level.

Until now, we reclaimed memcgs like this:

    mem = mem_cgroup_iter(root)
    for each priority level:
      for each zone in zonelist:
        reclaim(mem, zone)

But subsequent patches will move the memcg iteration inside the loop
over the zones:

    for each priority level:
      for each zone in zonelist:
        mem = mem_cgroup_iter(root)
        reclaim(mem, zone)

And to keep with the original scan order - memcg -> priority -> zone -
the last scanned memcg has to be remembered per zone and per priority
level.

Furthermore, global reclaim will be switched to the hierarchy walk as
well.  Different from limit reclaim, which can just recheck the limit
after some reclaim progress, its target is to scan all memcgs for the
desired zone pages, proportional to the memcg size, and so reliably
detecting a full hierarchy round-trip will become crucial.

Currently, the code relies on one reclaimer encountering the same
memcg twice, but that is error-prone with concurrent reclaimers.
Instead, use a generation counter that is increased every time the
child with the highest ID has been visited, so that reclaimers can
stop when the generation changes.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
---
 mm/memcontrol.c |   65 +++++++++++++++++++++++++++++++++++++++---------------
 1 files changed, 47 insertions(+), 18 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 77049f7..100595b 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -121,6 +121,13 @@ struct mem_cgroup_stat_cpu {
 	unsigned long targets[MEM_CGROUP_NTARGETS];
 };
 
+struct mem_cgroup_reclaim_iter {
+	/* css_id of the last scanned hierarchy member */
+	int position;
+	/* scan generation, increased every round-trip */
+	unsigned int generation;
+};
+
 /*
  * per-zone information in memory controller.
  */
@@ -131,6 +138,8 @@ struct mem_cgroup_per_zone {
 	struct list_head	lists[NR_LRU_LISTS];
 	unsigned long		count[NR_LRU_LISTS];
 
+	struct mem_cgroup_reclaim_iter reclaim_iter[DEF_PRIORITY + 1];
+
 	struct zone_reclaim_stat reclaim_stat;
 	struct rb_node		tree_node;	/* RB tree node */
 	unsigned long long	usage_in_excess;/* Set to the value by which */
@@ -231,11 +240,6 @@ struct mem_cgroup {
 	 * per zone LRU lists.
 	 */
 	struct mem_cgroup_lru_info info;
-	/*
-	 * While reclaiming in a hierarchy, we cache the last child we
-	 * reclaimed from.
-	 */
-	int last_scanned_child;
 	int last_scanned_node;
 #if MAX_NUMNODES > 1
 	nodemask_t	scan_nodes;
@@ -787,9 +791,16 @@ struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
 	return memcg;
 }
 
-static struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
-					  struct mem_cgroup *prev,
-					  bool reclaim)
+struct mem_cgroup_reclaim_cookie {
+	struct zone *zone;
+	int priority;
+	unsigned int generation;
+};
+
+static struct mem_cgroup *
+mem_cgroup_iter(struct mem_cgroup *root,
+		struct mem_cgroup *prev,
+		struct mem_cgroup_reclaim_cookie *reclaim)
 {
 	struct mem_cgroup *memcg = NULL;
 	int id = 0;
@@ -810,10 +821,20 @@ static struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
 	}
 
 	while (!memcg) {
+		struct mem_cgroup_reclaim_iter *uninitialized_var(iter);
 		struct cgroup_subsys_state *css;
 
-		if (reclaim)
-			id = root->last_scanned_child;
+		if (reclaim) {
+			int nid = zone_to_nid(reclaim->zone);
+			int zid = zone_idx(reclaim->zone);
+			struct mem_cgroup_per_zone *mz;
+
+			mz = mem_cgroup_zoneinfo(root, nid, zid);
+			iter = &mz->reclaim_iter[reclaim->priority];
+			if (prev && reclaim->generation != iter->generation)
+				return NULL;
+			id = iter->position;
+		}
 
 		rcu_read_lock();
 		css = css_get_next(&mem_cgroup_subsys, id + 1, &root->css, &id);
@@ -825,8 +846,13 @@ static struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
 			id = 0;
 		rcu_read_unlock();
 
-		if (reclaim)
-			root->last_scanned_child = id;
+		if (reclaim) {
+			iter->position = id;
+			if (!css)
+				iter->generation++;
+			else if (!prev && memcg)
+				reclaim->generation = iter->generation;
+		}
 
 		if (prev && !css)
 			return NULL;
@@ -849,14 +875,14 @@ static void mem_cgroup_iter_break(struct mem_cgroup *root,
  * be used for reference counting.
  */
 #define for_each_mem_cgroup_tree(iter, root)		\
-	for (iter = mem_cgroup_iter(root, NULL, false);	\
+	for (iter = mem_cgroup_iter(root, NULL, NULL);	\
 	     iter != NULL;				\
-	     iter = mem_cgroup_iter(root, iter, false))
+	     iter = mem_cgroup_iter(root, iter, NULL))
 
 #define for_each_mem_cgroup(iter)			\
-	for (iter = mem_cgroup_iter(NULL, NULL, false);	\
+	for (iter = mem_cgroup_iter(NULL, NULL, NULL);	\
 	     iter != NULL;				\
-	     iter = mem_cgroup_iter(NULL, iter, false))
+	     iter = mem_cgroup_iter(NULL, iter, NULL))
 
 static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
 {
@@ -1626,6 +1652,10 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
 	bool check_soft = reclaim_options & MEM_CGROUP_RECLAIM_SOFT;
 	unsigned long excess;
 	unsigned long nr_scanned;
+	struct mem_cgroup_reclaim_cookie reclaim = {
+		.zone = zone,
+		.priority = 0,
+	};
 
 	excess = res_counter_soft_limit_excess(&root_memcg->res) >> PAGE_SHIFT;
 
@@ -1634,7 +1664,7 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
 		noswap = true;
 
 	while (1) {
-		victim = mem_cgroup_iter(root_memcg, victim, true);
+		victim = mem_cgroup_iter(root_memcg, victim, &reclaim);
 		if (!victim) {
 			loop++;
 			/*
@@ -4887,7 +4917,6 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
 		res_counter_init(&memcg->res, NULL);
 		res_counter_init(&memcg->memsw, NULL);
 	}
-	memcg->last_scanned_child = 0;
 	memcg->last_scanned_node = MAX_NUMNODES;
 	INIT_LIST_HEAD(&memcg->oom_notify);
 
-- 
1.7.6.4


^ permalink raw reply related	[flat|nested] 32+ messages in thread
* [patch 04/10] mm: memcg: per-priority per-zone hierarchy scan generations
@ 2011-11-08 21:23   ` Johannes Weiner
  0 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-11-08 21:23 UTC (permalink / raw)
  To: Andrew Morton
  Cc: KAMEZAWA Hiroyuki, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel

Memory cgroup limit reclaim currently picks one memory cgroup out of
the target hierarchy, remembers it as the last scanned child, and
reclaims all zones in it with decreasing priority levels.

The new hierarchy reclaim code will pick memory cgroups from the same
hierarchy concurrently from different zones and priority levels, it
becomes necessary that hierarchy roots not only remember the last
scanned child, but do so for each zone and priority level.

Until now, we reclaimed memcgs like this:

    mem = mem_cgroup_iter(root)
    for each priority level:
      for each zone in zonelist:
        reclaim(mem, zone)

But subsequent patches will move the memcg iteration inside the loop
over the zones:

    for each priority level:
      for each zone in zonelist:
        mem = mem_cgroup_iter(root)
        reclaim(mem, zone)

And to keep with the original scan order - memcg -> priority -> zone -
the last scanned memcg has to be remembered per zone and per priority
level.

Furthermore, global reclaim will be switched to the hierarchy walk as
well.  Different from limit reclaim, which can just recheck the limit
after some reclaim progress, its target is to scan all memcgs for the
desired zone pages, proportional to the memcg size, and so reliably
detecting a full hierarchy round-trip will become crucial.

Currently, the code relies on one reclaimer encountering the same
memcg twice, but that is error-prone with concurrent reclaimers.
Instead, use a generation counter that is increased every time the
child with the highest ID has been visited, so that reclaimers can
stop when the generation changes.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
---
 mm/memcontrol.c |   65 +++++++++++++++++++++++++++++++++++++++---------------
 1 files changed, 47 insertions(+), 18 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 77049f7..100595b 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -121,6 +121,13 @@ struct mem_cgroup_stat_cpu {
 	unsigned long targets[MEM_CGROUP_NTARGETS];
 };
 
+struct mem_cgroup_reclaim_iter {
+	/* css_id of the last scanned hierarchy member */
+	int position;
+	/* scan generation, increased every round-trip */
+	unsigned int generation;
+};
+
 /*
  * per-zone information in memory controller.
  */
@@ -131,6 +138,8 @@ struct mem_cgroup_per_zone {
 	struct list_head	lists[NR_LRU_LISTS];
 	unsigned long		count[NR_LRU_LISTS];
 
+	struct mem_cgroup_reclaim_iter reclaim_iter[DEF_PRIORITY + 1];
+
 	struct zone_reclaim_stat reclaim_stat;
 	struct rb_node		tree_node;	/* RB tree node */
 	unsigned long long	usage_in_excess;/* Set to the value by which */
@@ -231,11 +240,6 @@ struct mem_cgroup {
 	 * per zone LRU lists.
 	 */
 	struct mem_cgroup_lru_info info;
-	/*
-	 * While reclaiming in a hierarchy, we cache the last child we
-	 * reclaimed from.
-	 */
-	int last_scanned_child;
 	int last_scanned_node;
 #if MAX_NUMNODES > 1
 	nodemask_t	scan_nodes;
@@ -787,9 +791,16 @@ struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
 	return memcg;
 }
 
-static struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
-					  struct mem_cgroup *prev,
-					  bool reclaim)
+struct mem_cgroup_reclaim_cookie {
+	struct zone *zone;
+	int priority;
+	unsigned int generation;
+};
+
+static struct mem_cgroup *
+mem_cgroup_iter(struct mem_cgroup *root,
+		struct mem_cgroup *prev,
+		struct mem_cgroup_reclaim_cookie *reclaim)
 {
 	struct mem_cgroup *memcg = NULL;
 	int id = 0;
@@ -810,10 +821,20 @@ static struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
 	}
 
 	while (!memcg) {
+		struct mem_cgroup_reclaim_iter *uninitialized_var(iter);
 		struct cgroup_subsys_state *css;
 
-		if (reclaim)
-			id = root->last_scanned_child;
+		if (reclaim) {
+			int nid = zone_to_nid(reclaim->zone);
+			int zid = zone_idx(reclaim->zone);
+			struct mem_cgroup_per_zone *mz;
+
+			mz = mem_cgroup_zoneinfo(root, nid, zid);
+			iter = &mz->reclaim_iter[reclaim->priority];
+			if (prev && reclaim->generation != iter->generation)
+				return NULL;
+			id = iter->position;
+		}
 
 		rcu_read_lock();
 		css = css_get_next(&mem_cgroup_subsys, id + 1, &root->css, &id);
@@ -825,8 +846,13 @@ static struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
 			id = 0;
 		rcu_read_unlock();
 
-		if (reclaim)
-			root->last_scanned_child = id;
+		if (reclaim) {
+			iter->position = id;
+			if (!css)
+				iter->generation++;
+			else if (!prev && memcg)
+				reclaim->generation = iter->generation;
+		}
 
 		if (prev && !css)
 			return NULL;
@@ -849,14 +875,14 @@ static void mem_cgroup_iter_break(struct mem_cgroup *root,
  * be used for reference counting.
  */
 #define for_each_mem_cgroup_tree(iter, root)		\
-	for (iter = mem_cgroup_iter(root, NULL, false);	\
+	for (iter = mem_cgroup_iter(root, NULL, NULL);	\
 	     iter != NULL;				\
-	     iter = mem_cgroup_iter(root, iter, false))
+	     iter = mem_cgroup_iter(root, iter, NULL))
 
 #define for_each_mem_cgroup(iter)			\
-	for (iter = mem_cgroup_iter(NULL, NULL, false);	\
+	for (iter = mem_cgroup_iter(NULL, NULL, NULL);	\
 	     iter != NULL;				\
-	     iter = mem_cgroup_iter(NULL, iter, false))
+	     iter = mem_cgroup_iter(NULL, iter, NULL))
 
 static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
 {
@@ -1626,6 +1652,10 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
 	bool check_soft = reclaim_options & MEM_CGROUP_RECLAIM_SOFT;
 	unsigned long excess;
 	unsigned long nr_scanned;
+	struct mem_cgroup_reclaim_cookie reclaim = {
+		.zone = zone,
+		.priority = 0,
+	};
 
 	excess = res_counter_soft_limit_excess(&root_memcg->res) >> PAGE_SHIFT;
 
@@ -1634,7 +1664,7 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
 		noswap = true;
 
 	while (1) {
-		victim = mem_cgroup_iter(root_memcg, victim, true);
+		victim = mem_cgroup_iter(root_memcg, victim, &reclaim);
 		if (!victim) {
 			loop++;
 			/*
@@ -4887,7 +4917,6 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
 		res_counter_init(&memcg->res, NULL);
 		res_counter_init(&memcg->memsw, NULL);
 	}
-	memcg->last_scanned_child = 0;
 	memcg->last_scanned_node = MAX_NUMNODES;
 	INIT_LIST_HEAD(&memcg->oom_notify);
 
-- 
1.7.6.4

--
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^ permalink raw reply related	[flat|nested] 32+ messages in thread
* [patch 05/10] mm: move memcg hierarchy reclaim to generic reclaim code
  2011-11-08 21:23 ` Johannes Weiner
@ 2011-11-08 21:23   ` Johannes Weiner
  -1 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-11-08 21:23 UTC (permalink / raw)
  To: Andrew Morton
  Cc: KAMEZAWA Hiroyuki, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel

Memory cgroup limit reclaim and traditional global pressure reclaim
will soon share the same code to reclaim from a hierarchical tree of
memory cgroups.

In preparation of this, move the two right next to each other in
shrink_zone().

The mem_cgroup_hierarchical_reclaim() polymath is split into a soft
limit reclaim function, which still does hierarchy walking on its own,
and a limit (shrinking) reclaim function, which relies on generic
reclaim code to walk the hierarchy.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
---
 include/linux/memcontrol.h |   24 ++++++
 mm/memcontrol.c            |  169 ++++++++++++++++++++++----------------------
 mm/vmscan.c                |   43 ++++++++++-
 3 files changed, 148 insertions(+), 88 deletions(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index b87068a..6952016 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -40,6 +40,12 @@ extern unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
 					struct mem_cgroup *mem_cont,
 					int active, int file);
 
+struct mem_cgroup_reclaim_cookie {
+	struct zone *zone;
+	int priority;
+	unsigned int generation;
+};
+
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR
 /*
  * All "charge" functions with gfp_mask should use GFP_KERNEL or
@@ -103,6 +109,11 @@ mem_cgroup_prepare_migration(struct page *page,
 extern void mem_cgroup_end_migration(struct mem_cgroup *memcg,
 	struct page *oldpage, struct page *newpage, bool migration_ok);
 
+struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *,
+				   struct mem_cgroup *,
+				   struct mem_cgroup_reclaim_cookie *);
+void mem_cgroup_iter_break(struct mem_cgroup *, struct mem_cgroup *);
+
 /*
  * For memory reclaim.
  */
@@ -276,6 +287,19 @@ static inline void mem_cgroup_end_migration(struct mem_cgroup *memcg,
 {
 }
 
+static inline struct mem_cgroup *
+mem_cgroup_iter(struct mem_cgroup *root,
+		struct mem_cgroup *prev,
+		struct mem_cgroup_reclaim_cookie *reclaim)
+{
+	return NULL;
+}
+
+static inline void mem_cgroup_iter_break(struct mem_cgroup *root,
+					 struct mem_cgroup *prev)
+{
+}
+
 static inline int mem_cgroup_get_reclaim_priority(struct mem_cgroup *memcg)
 {
 	return 0;
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 100595b..4305686 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -364,8 +364,6 @@ enum charge_type {
 #define MEM_CGROUP_RECLAIM_NOSWAP	(1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
 #define MEM_CGROUP_RECLAIM_SHRINK_BIT	0x1
 #define MEM_CGROUP_RECLAIM_SHRINK	(1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
-#define MEM_CGROUP_RECLAIM_SOFT_BIT	0x2
-#define MEM_CGROUP_RECLAIM_SOFT		(1 << MEM_CGROUP_RECLAIM_SOFT_BIT)
 
 static void mem_cgroup_get(struct mem_cgroup *memcg);
 static void mem_cgroup_put(struct mem_cgroup *memcg);
@@ -791,20 +789,33 @@ struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
 	return memcg;
 }
 
-struct mem_cgroup_reclaim_cookie {
-	struct zone *zone;
-	int priority;
-	unsigned int generation;
-};
-
-static struct mem_cgroup *
-mem_cgroup_iter(struct mem_cgroup *root,
-		struct mem_cgroup *prev,
-		struct mem_cgroup_reclaim_cookie *reclaim)
+/**
+ * mem_cgroup_iter - iterate over memory cgroup hierarchy
+ * @root: hierarchy root
+ * @prev: previously returned memcg, NULL on first invocation
+ * @reclaim: cookie for shared reclaim walks, NULL for full walks
+ *
+ * Returns references to children of the hierarchy below @root, or
+ * @root itself, or %NULL after a full round-trip.
+ *
+ * Caller must pass the return value in @prev on subsequent
+ * invocations for reference counting, or use mem_cgroup_iter_break()
+ * to cancel a hierarchy walk before the round-trip is complete.
+ *
+ * Reclaimers can specify a zone and a priority level in @reclaim to
+ * divide up the memcgs in the hierarchy among all concurrent
+ * reclaimers operating on the same zone and priority.
+ */
+struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
+				   struct mem_cgroup *prev,
+				   struct mem_cgroup_reclaim_cookie *reclaim)
 {
 	struct mem_cgroup *memcg = NULL;
 	int id = 0;
 
+	if (mem_cgroup_disabled())
+		return NULL;
+
 	if (!root)
 		root = root_mem_cgroup;
 
@@ -860,8 +871,13 @@ mem_cgroup_iter(struct mem_cgroup *root,
 	return memcg;
 }
 
-static void mem_cgroup_iter_break(struct mem_cgroup *root,
-				  struct mem_cgroup *prev)
+/**
+ * mem_cgroup_iter_break - abort a hierarchy walk prematurely
+ * @root: hierarchy root
+ * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
+ */
+void mem_cgroup_iter_break(struct mem_cgroup *root,
+			   struct mem_cgroup *prev)
 {
 	if (!root)
 		root = root_mem_cgroup;
@@ -1489,6 +1505,42 @@ u64 mem_cgroup_get_limit(struct mem_cgroup *memcg)
 	return min(limit, memsw);
 }
 
+static unsigned long mem_cgroup_reclaim(struct mem_cgroup *memcg,
+					gfp_t gfp_mask,
+					unsigned long flags)
+{
+	unsigned long total = 0;
+	bool noswap = false;
+	int loop;
+
+	if (flags & MEM_CGROUP_RECLAIM_NOSWAP)
+		noswap = true;
+	if (!(flags & MEM_CGROUP_RECLAIM_SHRINK) && memcg->memsw_is_minimum)
+		noswap = true;
+
+	for (loop = 0; loop < MEM_CGROUP_MAX_RECLAIM_LOOPS; loop++) {
+		if (loop)
+			drain_all_stock_async(memcg);
+		total += try_to_free_mem_cgroup_pages(memcg, gfp_mask, noswap);
+		/*
+		 * Allow limit shrinkers, which are triggered directly
+		 * by userspace, to catch signals and stop reclaim
+		 * after minimal progress, regardless of the margin.
+		 */
+		if (total && (flags & MEM_CGROUP_RECLAIM_SHRINK))
+			break;
+		if (mem_cgroup_margin(memcg))
+			break;
+		/*
+		 * If nothing was reclaimed after two attempts, there
+		 * may be no reclaimable pages in this hierarchy.
+		 */
+		if (loop && !total)
+			break;
+	}
+	return total;
+}
+
 /**
  * test_mem_cgroup_node_reclaimable
  * @mem: the target memcg
@@ -1626,30 +1678,14 @@ bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap)
 }
 #endif
 
-/*
- * Scan the hierarchy if needed to reclaim memory. We remember the last child
- * we reclaimed from, so that we don't end up penalizing one child extensively
- * based on its position in the children list.
- *
- * root_memcg is the original ancestor that we've been reclaim from.
- *
- * We give up and return to the caller when we visit root_memcg twice.
- * (other groups can be removed while we're walking....)
- *
- * If shrink==true, for avoiding to free too much, this returns immedieately.
- */
-static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
-						struct zone *zone,
-						gfp_t gfp_mask,
-						unsigned long reclaim_options,
-						unsigned long *total_scanned)
+static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg,
+				   struct zone *zone,
+				   gfp_t gfp_mask,
+				   unsigned long *total_scanned)
 {
 	struct mem_cgroup *victim = NULL;
-	int ret, total = 0;
+	int total = 0;
 	int loop = 0;
-	bool noswap = reclaim_options & MEM_CGROUP_RECLAIM_NOSWAP;
-	bool shrink = reclaim_options & MEM_CGROUP_RECLAIM_SHRINK;
-	bool check_soft = reclaim_options & MEM_CGROUP_RECLAIM_SOFT;
 	unsigned long excess;
 	unsigned long nr_scanned;
 	struct mem_cgroup_reclaim_cookie reclaim = {
@@ -1659,29 +1695,17 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
 
 	excess = res_counter_soft_limit_excess(&root_memcg->res) >> PAGE_SHIFT;
 
-	/* If memsw_is_minimum==1, swap-out is of-no-use. */
-	if (!check_soft && !shrink && root_memcg->memsw_is_minimum)
-		noswap = true;
-
 	while (1) {
 		victim = mem_cgroup_iter(root_memcg, victim, &reclaim);
 		if (!victim) {
 			loop++;
-			/*
-			 * We are not draining per cpu cached charges during
-			 * soft limit reclaim  because global reclaim doesn't
-			 * care about charges. It tries to free some memory and
-			 * charges will not give any.
-			 */
-			if (!check_soft && loop >= 1)
-				drain_all_stock_async(root_memcg);
 			if (loop >= 2) {
 				/*
 				 * If we have not been able to reclaim
 				 * anything, it might because there are
 				 * no reclaimable pages under this hierarchy
 				 */
-				if (!check_soft || !total)
+				if (!total)
 					break;
 				/*
 				 * We want to do more targeted reclaim.
@@ -1695,30 +1719,12 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
 			}
 			continue;
 		}
-		if (!mem_cgroup_reclaimable(victim, noswap)) {
-			/* this cgroup's local usage == 0 */
+		if (!mem_cgroup_reclaimable(victim, false))
 			continue;
-		}
-		/* we use swappiness of local cgroup */
-		if (check_soft) {
-			ret = mem_cgroup_shrink_node_zone(victim, gfp_mask,
-				noswap, zone, &nr_scanned);
-			*total_scanned += nr_scanned;
-		} else
-			ret = try_to_free_mem_cgroup_pages(victim, gfp_mask,
-						noswap);
-		total += ret;
-		/*
-		 * At shrinking usage, we can't check we should stop here or
-		 * reclaim more. It's depends on callers. last_scanned_child
-		 * will work enough for keeping fairness under tree.
-		 */
-		if (shrink)
-			break;
-		if (check_soft) {
-			if (!res_counter_soft_limit_excess(&root_memcg->res))
-				break;
-		} else if (mem_cgroup_margin(root_memcg))
+		total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false,
+						     zone, &nr_scanned);
+		*total_scanned += nr_scanned;
+		if (!res_counter_soft_limit_excess(&root_memcg->res))
 			break;
 	}
 	mem_cgroup_iter_break(root_memcg, victim);
@@ -2215,8 +2221,7 @@ static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
 	if (!(gfp_mask & __GFP_WAIT))
 		return CHARGE_WOULDBLOCK;
 
-	ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, NULL,
-					      gfp_mask, flags, NULL);
+	ret = mem_cgroup_reclaim(mem_over_limit, gfp_mask, flags);
 	if (mem_cgroup_margin(mem_over_limit) >= nr_pages)
 		return CHARGE_RETRY;
 	/*
@@ -3449,9 +3454,8 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
 		if (!ret)
 			break;
 
-		mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL,
-						MEM_CGROUP_RECLAIM_SHRINK,
-						NULL);
+		mem_cgroup_reclaim(memcg, GFP_KERNEL,
+				   MEM_CGROUP_RECLAIM_SHRINK);
 		curusage = res_counter_read_u64(&memcg->res, RES_USAGE);
 		/* Usage is reduced ? */
   		if (curusage >= oldusage)
@@ -3509,10 +3513,9 @@ static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
 		if (!ret)
 			break;
 
-		mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL,
-						MEM_CGROUP_RECLAIM_NOSWAP |
-						MEM_CGROUP_RECLAIM_SHRINK,
-						NULL);
+		mem_cgroup_reclaim(memcg, GFP_KERNEL,
+				   MEM_CGROUP_RECLAIM_NOSWAP |
+				   MEM_CGROUP_RECLAIM_SHRINK);
 		curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
 		/* Usage is reduced ? */
 		if (curusage >= oldusage)
@@ -3555,10 +3558,8 @@ unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
 			break;
 
 		nr_scanned = 0;
-		reclaimed = mem_cgroup_hierarchical_reclaim(mz->mem, zone,
-						gfp_mask,
-						MEM_CGROUP_RECLAIM_SOFT,
-						&nr_scanned);
+		reclaimed = mem_cgroup_soft_reclaim(mz->mem, zone,
+						    gfp_mask, &nr_scanned);
 		nr_reclaimed += reclaimed;
 		*total_scanned += nr_scanned;
 		spin_lock(&mctz->lock);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index b8e22a9..10f8ca0 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2115,12 +2115,43 @@ restart:
 static void shrink_zone(int priority, struct zone *zone,
 			struct scan_control *sc)
 {
-	struct mem_cgroup_zone mz = {
-		.mem_cgroup = sc->target_mem_cgroup,
+	struct mem_cgroup *root = sc->target_mem_cgroup;
+	struct mem_cgroup_reclaim_cookie reclaim = {
 		.zone = zone,
+		.priority = priority,
 	};
+	struct mem_cgroup *memcg;
+
+	if (global_reclaim(sc)) {
+		struct mem_cgroup_zone mz = {
+			.mem_cgroup = NULL,
+			.zone = zone,
+		};
+
+		shrink_mem_cgroup_zone(priority, &mz, sc);
+		return;
+	}
+
+	memcg = mem_cgroup_iter(root, NULL, &reclaim);
+	do {
+		struct mem_cgroup_zone mz = {
+			.mem_cgroup = memcg,
+			.zone = zone,
+		};
 
-	shrink_mem_cgroup_zone(priority, &mz, sc);
+		shrink_mem_cgroup_zone(priority, &mz, sc);
+		/*
+		 * Limit reclaim has historically picked one memcg and
+		 * scanned it with decreasing priority levels until
+		 * nr_to_reclaim had been reclaimed.  This priority
+		 * cycle is thus over after a single memcg.
+		 */
+		if (!global_reclaim(sc)) {
+			mem_cgroup_iter_break(root, memcg);
+			break;
+		}
+		memcg = mem_cgroup_iter(root, memcg, &reclaim);
+	} while (memcg);
 }
 
 /*
@@ -2385,6 +2416,10 @@ unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
 		.order = 0,
 		.target_mem_cgroup = mem,
 	};
+	struct mem_cgroup_zone mz = {
+		.mem_cgroup = mem,
+		.zone = zone,
+	};
 
 	sc.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) |
 			(GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK);
@@ -2400,7 +2435,7 @@ unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
 	 * will pick up pages from other mem cgroup's as well. We hack
 	 * the priority and make it zero.
 	 */
-	shrink_zone(0, zone, &sc);
+	shrink_mem_cgroup_zone(0, &mz, &sc);
 
 	trace_mm_vmscan_memcg_softlimit_reclaim_end(sc.nr_reclaimed);
 
-- 
1.7.6.4


^ permalink raw reply related	[flat|nested] 32+ messages in thread
* [patch 05/10] mm: move memcg hierarchy reclaim to generic reclaim code
@ 2011-11-08 21:23   ` Johannes Weiner
  0 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-11-08 21:23 UTC (permalink / raw)
  To: Andrew Morton
  Cc: KAMEZAWA Hiroyuki, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel

Memory cgroup limit reclaim and traditional global pressure reclaim
will soon share the same code to reclaim from a hierarchical tree of
memory cgroups.

In preparation of this, move the two right next to each other in
shrink_zone().

The mem_cgroup_hierarchical_reclaim() polymath is split into a soft
limit reclaim function, which still does hierarchy walking on its own,
and a limit (shrinking) reclaim function, which relies on generic
reclaim code to walk the hierarchy.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
---
 include/linux/memcontrol.h |   24 ++++++
 mm/memcontrol.c            |  169 ++++++++++++++++++++++----------------------
 mm/vmscan.c                |   43 ++++++++++-
 3 files changed, 148 insertions(+), 88 deletions(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index b87068a..6952016 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -40,6 +40,12 @@ extern unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
 					struct mem_cgroup *mem_cont,
 					int active, int file);
 
+struct mem_cgroup_reclaim_cookie {
+	struct zone *zone;
+	int priority;
+	unsigned int generation;
+};
+
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR
 /*
  * All "charge" functions with gfp_mask should use GFP_KERNEL or
@@ -103,6 +109,11 @@ mem_cgroup_prepare_migration(struct page *page,
 extern void mem_cgroup_end_migration(struct mem_cgroup *memcg,
 	struct page *oldpage, struct page *newpage, bool migration_ok);
 
+struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *,
+				   struct mem_cgroup *,
+				   struct mem_cgroup_reclaim_cookie *);
+void mem_cgroup_iter_break(struct mem_cgroup *, struct mem_cgroup *);
+
 /*
  * For memory reclaim.
  */
@@ -276,6 +287,19 @@ static inline void mem_cgroup_end_migration(struct mem_cgroup *memcg,
 {
 }
 
+static inline struct mem_cgroup *
+mem_cgroup_iter(struct mem_cgroup *root,
+		struct mem_cgroup *prev,
+		struct mem_cgroup_reclaim_cookie *reclaim)
+{
+	return NULL;
+}
+
+static inline void mem_cgroup_iter_break(struct mem_cgroup *root,
+					 struct mem_cgroup *prev)
+{
+}
+
 static inline int mem_cgroup_get_reclaim_priority(struct mem_cgroup *memcg)
 {
 	return 0;
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 100595b..4305686 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -364,8 +364,6 @@ enum charge_type {
 #define MEM_CGROUP_RECLAIM_NOSWAP	(1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
 #define MEM_CGROUP_RECLAIM_SHRINK_BIT	0x1
 #define MEM_CGROUP_RECLAIM_SHRINK	(1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
-#define MEM_CGROUP_RECLAIM_SOFT_BIT	0x2
-#define MEM_CGROUP_RECLAIM_SOFT		(1 << MEM_CGROUP_RECLAIM_SOFT_BIT)
 
 static void mem_cgroup_get(struct mem_cgroup *memcg);
 static void mem_cgroup_put(struct mem_cgroup *memcg);
@@ -791,20 +789,33 @@ struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
 	return memcg;
 }
 
-struct mem_cgroup_reclaim_cookie {
-	struct zone *zone;
-	int priority;
-	unsigned int generation;
-};
-
-static struct mem_cgroup *
-mem_cgroup_iter(struct mem_cgroup *root,
-		struct mem_cgroup *prev,
-		struct mem_cgroup_reclaim_cookie *reclaim)
+/**
+ * mem_cgroup_iter - iterate over memory cgroup hierarchy
+ * @root: hierarchy root
+ * @prev: previously returned memcg, NULL on first invocation
+ * @reclaim: cookie for shared reclaim walks, NULL for full walks
+ *
+ * Returns references to children of the hierarchy below @root, or
+ * @root itself, or %NULL after a full round-trip.
+ *
+ * Caller must pass the return value in @prev on subsequent
+ * invocations for reference counting, or use mem_cgroup_iter_break()
+ * to cancel a hierarchy walk before the round-trip is complete.
+ *
+ * Reclaimers can specify a zone and a priority level in @reclaim to
+ * divide up the memcgs in the hierarchy among all concurrent
+ * reclaimers operating on the same zone and priority.
+ */
+struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
+				   struct mem_cgroup *prev,
+				   struct mem_cgroup_reclaim_cookie *reclaim)
 {
 	struct mem_cgroup *memcg = NULL;
 	int id = 0;
 
+	if (mem_cgroup_disabled())
+		return NULL;
+
 	if (!root)
 		root = root_mem_cgroup;
 
@@ -860,8 +871,13 @@ mem_cgroup_iter(struct mem_cgroup *root,
 	return memcg;
 }
 
-static void mem_cgroup_iter_break(struct mem_cgroup *root,
-				  struct mem_cgroup *prev)
+/**
+ * mem_cgroup_iter_break - abort a hierarchy walk prematurely
+ * @root: hierarchy root
+ * @prev: last visited hierarchy member as returned by mem_cgroup_iter()
+ */
+void mem_cgroup_iter_break(struct mem_cgroup *root,
+			   struct mem_cgroup *prev)
 {
 	if (!root)
 		root = root_mem_cgroup;
@@ -1489,6 +1505,42 @@ u64 mem_cgroup_get_limit(struct mem_cgroup *memcg)
 	return min(limit, memsw);
 }
 
+static unsigned long mem_cgroup_reclaim(struct mem_cgroup *memcg,
+					gfp_t gfp_mask,
+					unsigned long flags)
+{
+	unsigned long total = 0;
+	bool noswap = false;
+	int loop;
+
+	if (flags & MEM_CGROUP_RECLAIM_NOSWAP)
+		noswap = true;
+	if (!(flags & MEM_CGROUP_RECLAIM_SHRINK) && memcg->memsw_is_minimum)
+		noswap = true;
+
+	for (loop = 0; loop < MEM_CGROUP_MAX_RECLAIM_LOOPS; loop++) {
+		if (loop)
+			drain_all_stock_async(memcg);
+		total += try_to_free_mem_cgroup_pages(memcg, gfp_mask, noswap);
+		/*
+		 * Allow limit shrinkers, which are triggered directly
+		 * by userspace, to catch signals and stop reclaim
+		 * after minimal progress, regardless of the margin.
+		 */
+		if (total && (flags & MEM_CGROUP_RECLAIM_SHRINK))
+			break;
+		if (mem_cgroup_margin(memcg))
+			break;
+		/*
+		 * If nothing was reclaimed after two attempts, there
+		 * may be no reclaimable pages in this hierarchy.
+		 */
+		if (loop && !total)
+			break;
+	}
+	return total;
+}
+
 /**
  * test_mem_cgroup_node_reclaimable
  * @mem: the target memcg
@@ -1626,30 +1678,14 @@ bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap)
 }
 #endif
 
-/*
- * Scan the hierarchy if needed to reclaim memory. We remember the last child
- * we reclaimed from, so that we don't end up penalizing one child extensively
- * based on its position in the children list.
- *
- * root_memcg is the original ancestor that we've been reclaim from.
- *
- * We give up and return to the caller when we visit root_memcg twice.
- * (other groups can be removed while we're walking....)
- *
- * If shrink==true, for avoiding to free too much, this returns immedieately.
- */
-static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
-						struct zone *zone,
-						gfp_t gfp_mask,
-						unsigned long reclaim_options,
-						unsigned long *total_scanned)
+static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg,
+				   struct zone *zone,
+				   gfp_t gfp_mask,
+				   unsigned long *total_scanned)
 {
 	struct mem_cgroup *victim = NULL;
-	int ret, total = 0;
+	int total = 0;
 	int loop = 0;
-	bool noswap = reclaim_options & MEM_CGROUP_RECLAIM_NOSWAP;
-	bool shrink = reclaim_options & MEM_CGROUP_RECLAIM_SHRINK;
-	bool check_soft = reclaim_options & MEM_CGROUP_RECLAIM_SOFT;
 	unsigned long excess;
 	unsigned long nr_scanned;
 	struct mem_cgroup_reclaim_cookie reclaim = {
@@ -1659,29 +1695,17 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
 
 	excess = res_counter_soft_limit_excess(&root_memcg->res) >> PAGE_SHIFT;
 
-	/* If memsw_is_minimum==1, swap-out is of-no-use. */
-	if (!check_soft && !shrink && root_memcg->memsw_is_minimum)
-		noswap = true;
-
 	while (1) {
 		victim = mem_cgroup_iter(root_memcg, victim, &reclaim);
 		if (!victim) {
 			loop++;
-			/*
-			 * We are not draining per cpu cached charges during
-			 * soft limit reclaim  because global reclaim doesn't
-			 * care about charges. It tries to free some memory and
-			 * charges will not give any.
-			 */
-			if (!check_soft && loop >= 1)
-				drain_all_stock_async(root_memcg);
 			if (loop >= 2) {
 				/*
 				 * If we have not been able to reclaim
 				 * anything, it might because there are
 				 * no reclaimable pages under this hierarchy
 				 */
-				if (!check_soft || !total)
+				if (!total)
 					break;
 				/*
 				 * We want to do more targeted reclaim.
@@ -1695,30 +1719,12 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_memcg,
 			}
 			continue;
 		}
-		if (!mem_cgroup_reclaimable(victim, noswap)) {
-			/* this cgroup's local usage == 0 */
+		if (!mem_cgroup_reclaimable(victim, false))
 			continue;
-		}
-		/* we use swappiness of local cgroup */
-		if (check_soft) {
-			ret = mem_cgroup_shrink_node_zone(victim, gfp_mask,
-				noswap, zone, &nr_scanned);
-			*total_scanned += nr_scanned;
-		} else
-			ret = try_to_free_mem_cgroup_pages(victim, gfp_mask,
-						noswap);
-		total += ret;
-		/*
-		 * At shrinking usage, we can't check we should stop here or
-		 * reclaim more. It's depends on callers. last_scanned_child
-		 * will work enough for keeping fairness under tree.
-		 */
-		if (shrink)
-			break;
-		if (check_soft) {
-			if (!res_counter_soft_limit_excess(&root_memcg->res))
-				break;
-		} else if (mem_cgroup_margin(root_memcg))
+		total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false,
+						     zone, &nr_scanned);
+		*total_scanned += nr_scanned;
+		if (!res_counter_soft_limit_excess(&root_memcg->res))
 			break;
 	}
 	mem_cgroup_iter_break(root_memcg, victim);
@@ -2215,8 +2221,7 @@ static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
 	if (!(gfp_mask & __GFP_WAIT))
 		return CHARGE_WOULDBLOCK;
 
-	ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, NULL,
-					      gfp_mask, flags, NULL);
+	ret = mem_cgroup_reclaim(mem_over_limit, gfp_mask, flags);
 	if (mem_cgroup_margin(mem_over_limit) >= nr_pages)
 		return CHARGE_RETRY;
 	/*
@@ -3449,9 +3454,8 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
 		if (!ret)
 			break;
 
-		mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL,
-						MEM_CGROUP_RECLAIM_SHRINK,
-						NULL);
+		mem_cgroup_reclaim(memcg, GFP_KERNEL,
+				   MEM_CGROUP_RECLAIM_SHRINK);
 		curusage = res_counter_read_u64(&memcg->res, RES_USAGE);
 		/* Usage is reduced ? */
   		if (curusage >= oldusage)
@@ -3509,10 +3513,9 @@ static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
 		if (!ret)
 			break;
 
-		mem_cgroup_hierarchical_reclaim(memcg, NULL, GFP_KERNEL,
-						MEM_CGROUP_RECLAIM_NOSWAP |
-						MEM_CGROUP_RECLAIM_SHRINK,
-						NULL);
+		mem_cgroup_reclaim(memcg, GFP_KERNEL,
+				   MEM_CGROUP_RECLAIM_NOSWAP |
+				   MEM_CGROUP_RECLAIM_SHRINK);
 		curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
 		/* Usage is reduced ? */
 		if (curusage >= oldusage)
@@ -3555,10 +3558,8 @@ unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
 			break;
 
 		nr_scanned = 0;
-		reclaimed = mem_cgroup_hierarchical_reclaim(mz->mem, zone,
-						gfp_mask,
-						MEM_CGROUP_RECLAIM_SOFT,
-						&nr_scanned);
+		reclaimed = mem_cgroup_soft_reclaim(mz->mem, zone,
+						    gfp_mask, &nr_scanned);
 		nr_reclaimed += reclaimed;
 		*total_scanned += nr_scanned;
 		spin_lock(&mctz->lock);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index b8e22a9..10f8ca0 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2115,12 +2115,43 @@ restart:
 static void shrink_zone(int priority, struct zone *zone,
 			struct scan_control *sc)
 {
-	struct mem_cgroup_zone mz = {
-		.mem_cgroup = sc->target_mem_cgroup,
+	struct mem_cgroup *root = sc->target_mem_cgroup;
+	struct mem_cgroup_reclaim_cookie reclaim = {
 		.zone = zone,
+		.priority = priority,
 	};
+	struct mem_cgroup *memcg;
+
+	if (global_reclaim(sc)) {
+		struct mem_cgroup_zone mz = {
+			.mem_cgroup = NULL,
+			.zone = zone,
+		};
+
+		shrink_mem_cgroup_zone(priority, &mz, sc);
+		return;
+	}
+
+	memcg = mem_cgroup_iter(root, NULL, &reclaim);
+	do {
+		struct mem_cgroup_zone mz = {
+			.mem_cgroup = memcg,
+			.zone = zone,
+		};
 
-	shrink_mem_cgroup_zone(priority, &mz, sc);
+		shrink_mem_cgroup_zone(priority, &mz, sc);
+		/*
+		 * Limit reclaim has historically picked one memcg and
+		 * scanned it with decreasing priority levels until
+		 * nr_to_reclaim had been reclaimed.  This priority
+		 * cycle is thus over after a single memcg.
+		 */
+		if (!global_reclaim(sc)) {
+			mem_cgroup_iter_break(root, memcg);
+			break;
+		}
+		memcg = mem_cgroup_iter(root, memcg, &reclaim);
+	} while (memcg);
 }
 
 /*
@@ -2385,6 +2416,10 @@ unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
 		.order = 0,
 		.target_mem_cgroup = mem,
 	};
+	struct mem_cgroup_zone mz = {
+		.mem_cgroup = mem,
+		.zone = zone,
+	};
 
 	sc.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) |
 			(GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK);
@@ -2400,7 +2435,7 @@ unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
 	 * will pick up pages from other mem cgroup's as well. We hack
 	 * the priority and make it zero.
 	 */
-	shrink_zone(0, zone, &sc);
+	shrink_mem_cgroup_zone(0, &mz, &sc);
 
 	trace_mm_vmscan_memcg_softlimit_reclaim_end(sc.nr_reclaimed);
 
-- 
1.7.6.4

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
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^ permalink raw reply related	[flat|nested] 32+ messages in thread
* [patch 06/10] mm: memcg: remove optimization of keeping the root_mem_cgroup LRU lists empty
  2011-11-08 21:23 ` Johannes Weiner
@ 2011-11-08 21:23   ` Johannes Weiner
  -1 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-11-08 21:23 UTC (permalink / raw)
  To: Andrew Morton
  Cc: KAMEZAWA Hiroyuki, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel

root_mem_cgroup, lacking a configurable limit, was never subject to
limit reclaim, so the pages charged to it could be kept off its LRU
lists.  They would be found on the global per-zone LRU lists upon
physical memory pressure and it made sense to avoid uselessly linking
them to both lists.

The global per-zone LRU lists are about to go away on memcg-enabled
kernels, with all pages being exclusively linked to their respective
per-memcg LRU lists.  As a result, pages of the root_mem_cgroup must
also be linked to its LRU lists again.  This is purely about the LRU
list, root_mem_cgroup is still not charged.

The overhead is temporary until the double-LRU scheme is going away
completely.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
---
 mm/memcontrol.c |   12 ++----------
 1 files changed, 2 insertions(+), 10 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 4305686..bf84e2b 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -965,8 +965,6 @@ void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru)
 	mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
 	/* huge page split is done under lru_lock. so, we have no races. */
 	MEM_CGROUP_ZSTAT(mz, lru) -= 1 << compound_order(page);
-	if (mem_cgroup_is_root(pc->mem_cgroup))
-		return;
 	VM_BUG_ON(list_empty(&pc->lru));
 	list_del_init(&pc->lru);
 }
@@ -991,13 +989,11 @@ void mem_cgroup_rotate_reclaimable_page(struct page *page)
 		return;
 
 	pc = lookup_page_cgroup(page);
-	/* unused or root page is not rotated. */
+	/* unused page is not rotated. */
 	if (!PageCgroupUsed(pc))
 		return;
 	/* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
 	smp_rmb();
-	if (mem_cgroup_is_root(pc->mem_cgroup))
-		return;
 	mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
 	list_move_tail(&pc->lru, &mz->lists[lru]);
 }
@@ -1011,13 +1007,11 @@ void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
 		return;
 
 	pc = lookup_page_cgroup(page);
-	/* unused or root page is not rotated. */
+	/* unused page is not rotated. */
 	if (!PageCgroupUsed(pc))
 		return;
 	/* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
 	smp_rmb();
-	if (mem_cgroup_is_root(pc->mem_cgroup))
-		return;
 	mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
 	list_move(&pc->lru, &mz->lists[lru]);
 }
@@ -1049,8 +1043,6 @@ void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
 	/* huge page split is done under lru_lock. so, we have no races. */
 	MEM_CGROUP_ZSTAT(mz, lru) += 1 << compound_order(page);
 	SetPageCgroupAcctLRU(pc);
-	if (mem_cgroup_is_root(pc->mem_cgroup))
-		return;
 	list_add(&pc->lru, &mz->lists[lru]);
 }
 
-- 
1.7.6.4


^ permalink raw reply related	[flat|nested] 32+ messages in thread
* [patch 06/10] mm: memcg: remove optimization of keeping the root_mem_cgroup LRU lists empty
@ 2011-11-08 21:23   ` Johannes Weiner
  0 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-11-08 21:23 UTC (permalink / raw)
  To: Andrew Morton
  Cc: KAMEZAWA Hiroyuki, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel

root_mem_cgroup, lacking a configurable limit, was never subject to
limit reclaim, so the pages charged to it could be kept off its LRU
lists.  They would be found on the global per-zone LRU lists upon
physical memory pressure and it made sense to avoid uselessly linking
them to both lists.

The global per-zone LRU lists are about to go away on memcg-enabled
kernels, with all pages being exclusively linked to their respective
per-memcg LRU lists.  As a result, pages of the root_mem_cgroup must
also be linked to its LRU lists again.  This is purely about the LRU
list, root_mem_cgroup is still not charged.

The overhead is temporary until the double-LRU scheme is going away
completely.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
---
 mm/memcontrol.c |   12 ++----------
 1 files changed, 2 insertions(+), 10 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 4305686..bf84e2b 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -965,8 +965,6 @@ void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru)
 	mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
 	/* huge page split is done under lru_lock. so, we have no races. */
 	MEM_CGROUP_ZSTAT(mz, lru) -= 1 << compound_order(page);
-	if (mem_cgroup_is_root(pc->mem_cgroup))
-		return;
 	VM_BUG_ON(list_empty(&pc->lru));
 	list_del_init(&pc->lru);
 }
@@ -991,13 +989,11 @@ void mem_cgroup_rotate_reclaimable_page(struct page *page)
 		return;
 
 	pc = lookup_page_cgroup(page);
-	/* unused or root page is not rotated. */
+	/* unused page is not rotated. */
 	if (!PageCgroupUsed(pc))
 		return;
 	/* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
 	smp_rmb();
-	if (mem_cgroup_is_root(pc->mem_cgroup))
-		return;
 	mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
 	list_move_tail(&pc->lru, &mz->lists[lru]);
 }
@@ -1011,13 +1007,11 @@ void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
 		return;
 
 	pc = lookup_page_cgroup(page);
-	/* unused or root page is not rotated. */
+	/* unused page is not rotated. */
 	if (!PageCgroupUsed(pc))
 		return;
 	/* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
 	smp_rmb();
-	if (mem_cgroup_is_root(pc->mem_cgroup))
-		return;
 	mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
 	list_move(&pc->lru, &mz->lists[lru]);
 }
@@ -1049,8 +1043,6 @@ void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
 	/* huge page split is done under lru_lock. so, we have no races. */
 	MEM_CGROUP_ZSTAT(mz, lru) += 1 << compound_order(page);
 	SetPageCgroupAcctLRU(pc);
-	if (mem_cgroup_is_root(pc->mem_cgroup))
-		return;
 	list_add(&pc->lru, &mz->lists[lru]);
 }
 
-- 
1.7.6.4

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply related	[flat|nested] 32+ messages in thread
* [patch 07/10] mm: vmscan: convert global reclaim to per-memcg LRU lists
  2011-11-08 21:23 ` Johannes Weiner
@ 2011-11-08 21:23   ` Johannes Weiner
  -1 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-11-08 21:23 UTC (permalink / raw)
  To: Andrew Morton
  Cc: KAMEZAWA Hiroyuki, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel

The global per-zone LRU lists are about to go away on memcg-enabled
kernels, global reclaim must be able to find its pages on the
per-memcg LRU lists.

Since the LRU pages of a zone are distributed over all existing memory
cgroups, a scan target for a zone is complete when all memory cgroups
are scanned for their proportional share of a zone's memory.

The forced scanning of small scan targets from kswapd is limited to
zones marked unreclaimable, otherwise kswapd can quickly overreclaim
by force-scanning the LRU lists of multiple memory cgroups.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
---
 mm/vmscan.c |   39 ++++++++++++++++++++++-----------------
 1 files changed, 22 insertions(+), 17 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 10f8ca0..e214e02 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1898,7 +1898,7 @@ static void get_scan_count(struct mem_cgroup_zone *mz, struct scan_control *sc,
 	 * latencies, so it's better to scan a minimum amount there as
 	 * well.
 	 */
-	if (current_is_kswapd())
+	if (current_is_kswapd() && mz->zone->all_unreclaimable)
 		force_scan = true;
 	if (!global_reclaim(sc))
 		force_scan = true;
@@ -2122,16 +2122,6 @@ static void shrink_zone(int priority, struct zone *zone,
 	};
 	struct mem_cgroup *memcg;
 
-	if (global_reclaim(sc)) {
-		struct mem_cgroup_zone mz = {
-			.mem_cgroup = NULL,
-			.zone = zone,
-		};
-
-		shrink_mem_cgroup_zone(priority, &mz, sc);
-		return;
-	}
-
 	memcg = mem_cgroup_iter(root, NULL, &reclaim);
 	do {
 		struct mem_cgroup_zone mz = {
@@ -2145,6 +2135,10 @@ static void shrink_zone(int priority, struct zone *zone,
 		 * scanned it with decreasing priority levels until
 		 * nr_to_reclaim had been reclaimed.  This priority
 		 * cycle is thus over after a single memcg.
+		 *
+		 * Direct reclaim and kswapd, on the other hand, have
+		 * to scan all memory cgroups to fulfill the overall
+		 * scan target for the zone.
 		 */
 		if (!global_reclaim(sc)) {
 			mem_cgroup_iter_break(root, memcg);
@@ -2489,13 +2483,24 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
 static void age_active_anon(struct zone *zone, struct scan_control *sc,
 			    int priority)
 {
-	struct mem_cgroup_zone mz = {
-		.mem_cgroup = NULL,
-		.zone = zone,
-	};
+	struct mem_cgroup *memcg;
 
-	if (inactive_anon_is_low(&mz))
-		shrink_active_list(SWAP_CLUSTER_MAX, &mz, sc, priority, 0);
+	if (!total_swap_pages)
+		return;
+
+	memcg = mem_cgroup_iter(NULL, NULL, NULL);
+	do {
+		struct mem_cgroup_zone mz = {
+			.mem_cgroup = memcg,
+			.zone = zone,
+		};
+
+		if (inactive_anon_is_low(&mz))
+			shrink_active_list(SWAP_CLUSTER_MAX, &mz,
+					   sc, priority, 0);
+
+		memcg = mem_cgroup_iter(NULL, memcg, NULL);
+	} while (memcg);
 }
 
 /*
-- 
1.7.6.4


^ permalink raw reply related	[flat|nested] 32+ messages in thread
* [patch 07/10] mm: vmscan: convert global reclaim to per-memcg LRU lists
@ 2011-11-08 21:23   ` Johannes Weiner
  0 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-11-08 21:23 UTC (permalink / raw)
  To: Andrew Morton
  Cc: KAMEZAWA Hiroyuki, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel

The global per-zone LRU lists are about to go away on memcg-enabled
kernels, global reclaim must be able to find its pages on the
per-memcg LRU lists.

Since the LRU pages of a zone are distributed over all existing memory
cgroups, a scan target for a zone is complete when all memory cgroups
are scanned for their proportional share of a zone's memory.

The forced scanning of small scan targets from kswapd is limited to
zones marked unreclaimable, otherwise kswapd can quickly overreclaim
by force-scanning the LRU lists of multiple memory cgroups.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
---
 mm/vmscan.c |   39 ++++++++++++++++++++++-----------------
 1 files changed, 22 insertions(+), 17 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 10f8ca0..e214e02 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1898,7 +1898,7 @@ static void get_scan_count(struct mem_cgroup_zone *mz, struct scan_control *sc,
 	 * latencies, so it's better to scan a minimum amount there as
 	 * well.
 	 */
-	if (current_is_kswapd())
+	if (current_is_kswapd() && mz->zone->all_unreclaimable)
 		force_scan = true;
 	if (!global_reclaim(sc))
 		force_scan = true;
@@ -2122,16 +2122,6 @@ static void shrink_zone(int priority, struct zone *zone,
 	};
 	struct mem_cgroup *memcg;
 
-	if (global_reclaim(sc)) {
-		struct mem_cgroup_zone mz = {
-			.mem_cgroup = NULL,
-			.zone = zone,
-		};
-
-		shrink_mem_cgroup_zone(priority, &mz, sc);
-		return;
-	}
-
 	memcg = mem_cgroup_iter(root, NULL, &reclaim);
 	do {
 		struct mem_cgroup_zone mz = {
@@ -2145,6 +2135,10 @@ static void shrink_zone(int priority, struct zone *zone,
 		 * scanned it with decreasing priority levels until
 		 * nr_to_reclaim had been reclaimed.  This priority
 		 * cycle is thus over after a single memcg.
+		 *
+		 * Direct reclaim and kswapd, on the other hand, have
+		 * to scan all memory cgroups to fulfill the overall
+		 * scan target for the zone.
 		 */
 		if (!global_reclaim(sc)) {
 			mem_cgroup_iter_break(root, memcg);
@@ -2489,13 +2483,24 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
 static void age_active_anon(struct zone *zone, struct scan_control *sc,
 			    int priority)
 {
-	struct mem_cgroup_zone mz = {
-		.mem_cgroup = NULL,
-		.zone = zone,
-	};
+	struct mem_cgroup *memcg;
 
-	if (inactive_anon_is_low(&mz))
-		shrink_active_list(SWAP_CLUSTER_MAX, &mz, sc, priority, 0);
+	if (!total_swap_pages)
+		return;
+
+	memcg = mem_cgroup_iter(NULL, NULL, NULL);
+	do {
+		struct mem_cgroup_zone mz = {
+			.mem_cgroup = memcg,
+			.zone = zone,
+		};
+
+		if (inactive_anon_is_low(&mz))
+			shrink_active_list(SWAP_CLUSTER_MAX, &mz,
+					   sc, priority, 0);
+
+		memcg = mem_cgroup_iter(NULL, memcg, NULL);
+	} while (memcg);
 }
 
 /*
-- 
1.7.6.4

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^ permalink raw reply related	[flat|nested] 32+ messages in thread
* [patch 08/10] mm: collect LRU list heads into struct lruvec
  2011-11-08 21:23 ` Johannes Weiner
@ 2011-11-08 21:23   ` Johannes Weiner
  -1 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-11-08 21:23 UTC (permalink / raw)
  To: Andrew Morton
  Cc: KAMEZAWA Hiroyuki, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel

Having a unified structure with a LRU list set for both global zones
and per-memcg zones allows to keep that code simple which deals with
LRU lists and does not care about the container itself.

Once the per-memcg LRU lists directly link struct pages, the isolation
function and all other list manipulations are shared between the memcg
case and the global LRU case.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
---
 include/linux/mm_inline.h |    2 +-
 include/linux/mmzone.h    |   10 ++++++----
 mm/memcontrol.c           |   17 +++++++----------
 mm/page_alloc.c           |    2 +-
 mm/swap.c                 |   11 +++++------
 mm/vmscan.c               |   10 +++++-----
 6 files changed, 25 insertions(+), 27 deletions(-)

diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
index 8f7d247..e6a7ffe 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -33,7 +33,7 @@ __add_page_to_lru_list(struct zone *zone, struct page *page, enum lru_list l,
 static inline void
 add_page_to_lru_list(struct zone *zone, struct page *page, enum lru_list l)
 {
-	__add_page_to_lru_list(zone, page, l, &zone->lru[l].list);
+	__add_page_to_lru_list(zone, page, l, &zone->lruvec.lists[l]);
 }
 
 static inline void
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 188cb2f..9b97bed 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -159,6 +159,10 @@ static inline int is_unevictable_lru(enum lru_list l)
 	return (l == LRU_UNEVICTABLE);
 }
 
+struct lruvec {
+	struct list_head lists[NR_LRU_LISTS];
+};
+
 /* Mask used at gathering information at once (see memcontrol.c) */
 #define LRU_ALL_FILE (BIT(LRU_INACTIVE_FILE) | BIT(LRU_ACTIVE_FILE))
 #define LRU_ALL_ANON (BIT(LRU_INACTIVE_ANON) | BIT(LRU_ACTIVE_ANON))
@@ -358,10 +362,8 @@ struct zone {
 	ZONE_PADDING(_pad1_)
 
 	/* Fields commonly accessed by the page reclaim scanner */
-	spinlock_t		lru_lock;	
-	struct zone_lru {
-		struct list_head list;
-	} lru[NR_LRU_LISTS];
+	spinlock_t		lru_lock;
+	struct lruvec		lruvec;
 
 	struct zone_reclaim_stat reclaim_stat;
 
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index bf84e2b..22f25b0 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -132,10 +132,7 @@ struct mem_cgroup_reclaim_iter {
  * per-zone information in memory controller.
  */
 struct mem_cgroup_per_zone {
-	/*
-	 * spin_lock to protect the per cgroup LRU
-	 */
-	struct list_head	lists[NR_LRU_LISTS];
+	struct lruvec		lruvec;
 	unsigned long		count[NR_LRU_LISTS];
 
 	struct mem_cgroup_reclaim_iter reclaim_iter[DEF_PRIORITY + 1];
@@ -995,7 +992,7 @@ void mem_cgroup_rotate_reclaimable_page(struct page *page)
 	/* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
 	smp_rmb();
 	mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
-	list_move_tail(&pc->lru, &mz->lists[lru]);
+	list_move_tail(&pc->lru, &mz->lruvec.lists[lru]);
 }
 
 void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
@@ -1013,7 +1010,7 @@ void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
 	/* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
 	smp_rmb();
 	mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
-	list_move(&pc->lru, &mz->lists[lru]);
+	list_move(&pc->lru, &mz->lruvec.lists[lru]);
 }
 
 void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
@@ -1043,7 +1040,7 @@ void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
 	/* huge page split is done under lru_lock. so, we have no races. */
 	MEM_CGROUP_ZSTAT(mz, lru) += 1 << compound_order(page);
 	SetPageCgroupAcctLRU(pc);
-	list_add(&pc->lru, &mz->lists[lru]);
+	list_add(&pc->lru, &mz->lruvec.lists[lru]);
 }
 
 /*
@@ -1241,7 +1238,7 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
 
 	BUG_ON(!mem_cont);
 	mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
-	src = &mz->lists[lru];
+	src = &mz->lruvec.lists[lru];
 
 	scan = 0;
 	list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
@@ -3628,7 +3625,7 @@ static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg,
 
 	zone = &NODE_DATA(node)->node_zones[zid];
 	mz = mem_cgroup_zoneinfo(memcg, node, zid);
-	list = &mz->lists[lru];
+	list = &mz->lruvec.lists[lru];
 
 	loop = MEM_CGROUP_ZSTAT(mz, lru);
 	/* give some margin against EBUSY etc...*/
@@ -4724,7 +4721,7 @@ static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
 	for (zone = 0; zone < MAX_NR_ZONES; zone++) {
 		mz = &pn->zoneinfo[zone];
 		for_each_lru(l)
-			INIT_LIST_HEAD(&mz->lists[l]);
+			INIT_LIST_HEAD(&mz->lruvec.lists[l]);
 		mz->usage_in_excess = 0;
 		mz->on_tree = false;
 		mz->mem = memcg;
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 9dd443d..9310f31 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4341,7 +4341,7 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat,
 
 		zone_pcp_init(zone);
 		for_each_lru(l)
-			INIT_LIST_HEAD(&zone->lru[l].list);
+			INIT_LIST_HEAD(&zone->lruvec.lists[l]);
 		zone->reclaim_stat.recent_rotated[0] = 0;
 		zone->reclaim_stat.recent_rotated[1] = 0;
 		zone->reclaim_stat.recent_scanned[0] = 0;
diff --git a/mm/swap.c b/mm/swap.c
index a91caf7..5de4443 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -236,7 +236,7 @@ static void pagevec_move_tail_fn(struct page *page, void *arg)
 
 	if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
 		enum lru_list lru = page_lru_base_type(page);
-		list_move_tail(&page->lru, &zone->lru[lru].list);
+		list_move_tail(&page->lru, &zone->lruvec.lists[lru]);
 		mem_cgroup_rotate_reclaimable_page(page);
 		(*pgmoved)++;
 	}
@@ -480,7 +480,7 @@ static void lru_deactivate_fn(struct page *page, void *arg)
 		 * The page's writeback ends up during pagevec
 		 * We moves tha page into tail of inactive.
 		 */
-		list_move_tail(&page->lru, &zone->lru[lru].list);
+		list_move_tail(&page->lru, &zone->lruvec.lists[lru]);
 		mem_cgroup_rotate_reclaimable_page(page);
 		__count_vm_event(PGROTATED);
 	}
@@ -662,7 +662,6 @@ void lru_add_page_tail(struct zone* zone,
 	int active;
 	enum lru_list lru;
 	const int file = 0;
-	struct list_head *head;
 
 	VM_BUG_ON(!PageHead(page));
 	VM_BUG_ON(PageCompound(page_tail));
@@ -682,10 +681,10 @@ void lru_add_page_tail(struct zone* zone,
 		}
 		update_page_reclaim_stat(zone, page_tail, file, active);
 		if (likely(PageLRU(page)))
-			head = page->lru.prev;
+			__add_page_to_lru_list(zone, page_tail, lru,
+					       page->lru.prev);
 		else
-			head = &zone->lru[lru].list;
-		__add_page_to_lru_list(zone, page_tail, lru, head);
+			add_page_to_lru_list(zone, page_tail, lru);
 	} else {
 		SetPageUnevictable(page_tail);
 		add_page_to_lru_list(zone, page_tail, LRU_UNEVICTABLE);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index e214e02..174deff 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1262,8 +1262,8 @@ static unsigned long isolate_pages_global(unsigned long nr,
 		lru += LRU_ACTIVE;
 	if (file)
 		lru += LRU_FILE;
-	return isolate_lru_pages(nr, &z->lru[lru].list, dst, scanned, order,
-								mode, file);
+	return isolate_lru_pages(nr, &z->lruvec.lists[lru], dst,
+				 scanned, order, mode, file);
 }
 
 /*
@@ -1642,7 +1642,7 @@ static void move_active_pages_to_lru(struct zone *zone,
 		VM_BUG_ON(PageLRU(page));
 		SetPageLRU(page);
 
-		list_move(&page->lru, &zone->lru[lru].list);
+		list_move(&page->lru, &zone->lruvec.lists[lru]);
 		mem_cgroup_add_lru_list(page, lru);
 		pgmoved += hpage_nr_pages(page);
 
@@ -3459,7 +3459,7 @@ retry:
 		enum lru_list l = page_lru_base_type(page);
 
 		__dec_zone_state(zone, NR_UNEVICTABLE);
-		list_move(&page->lru, &zone->lru[l].list);
+		list_move(&page->lru, &zone->lruvec.lists[l]);
 		mem_cgroup_move_lists(page, LRU_UNEVICTABLE, l);
 		__inc_zone_state(zone, NR_INACTIVE_ANON + l);
 		__count_vm_event(UNEVICTABLE_PGRESCUED);
@@ -3468,7 +3468,7 @@ retry:
 		 * rotate unevictable list
 		 */
 		SetPageUnevictable(page);
-		list_move(&page->lru, &zone->lru[LRU_UNEVICTABLE].list);
+		list_move(&page->lru, &zone->lruvec.lists[LRU_UNEVICTABLE]);
 		mem_cgroup_rotate_lru_list(page, LRU_UNEVICTABLE);
 		if (page_evictable(page, NULL))
 			goto retry;
-- 
1.7.6.4


^ permalink raw reply related	[flat|nested] 32+ messages in thread
* [patch 08/10] mm: collect LRU list heads into struct lruvec
@ 2011-11-08 21:23   ` Johannes Weiner
  0 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-11-08 21:23 UTC (permalink / raw)
  To: Andrew Morton
  Cc: KAMEZAWA Hiroyuki, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel

Having a unified structure with a LRU list set for both global zones
and per-memcg zones allows to keep that code simple which deals with
LRU lists and does not care about the container itself.

Once the per-memcg LRU lists directly link struct pages, the isolation
function and all other list manipulations are shared between the memcg
case and the global LRU case.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
---
 include/linux/mm_inline.h |    2 +-
 include/linux/mmzone.h    |   10 ++++++----
 mm/memcontrol.c           |   17 +++++++----------
 mm/page_alloc.c           |    2 +-
 mm/swap.c                 |   11 +++++------
 mm/vmscan.c               |   10 +++++-----
 6 files changed, 25 insertions(+), 27 deletions(-)

diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
index 8f7d247..e6a7ffe 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -33,7 +33,7 @@ __add_page_to_lru_list(struct zone *zone, struct page *page, enum lru_list l,
 static inline void
 add_page_to_lru_list(struct zone *zone, struct page *page, enum lru_list l)
 {
-	__add_page_to_lru_list(zone, page, l, &zone->lru[l].list);
+	__add_page_to_lru_list(zone, page, l, &zone->lruvec.lists[l]);
 }
 
 static inline void
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 188cb2f..9b97bed 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -159,6 +159,10 @@ static inline int is_unevictable_lru(enum lru_list l)
 	return (l == LRU_UNEVICTABLE);
 }
 
+struct lruvec {
+	struct list_head lists[NR_LRU_LISTS];
+};
+
 /* Mask used at gathering information at once (see memcontrol.c) */
 #define LRU_ALL_FILE (BIT(LRU_INACTIVE_FILE) | BIT(LRU_ACTIVE_FILE))
 #define LRU_ALL_ANON (BIT(LRU_INACTIVE_ANON) | BIT(LRU_ACTIVE_ANON))
@@ -358,10 +362,8 @@ struct zone {
 	ZONE_PADDING(_pad1_)
 
 	/* Fields commonly accessed by the page reclaim scanner */
-	spinlock_t		lru_lock;	
-	struct zone_lru {
-		struct list_head list;
-	} lru[NR_LRU_LISTS];
+	spinlock_t		lru_lock;
+	struct lruvec		lruvec;
 
 	struct zone_reclaim_stat reclaim_stat;
 
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index bf84e2b..22f25b0 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -132,10 +132,7 @@ struct mem_cgroup_reclaim_iter {
  * per-zone information in memory controller.
  */
 struct mem_cgroup_per_zone {
-	/*
-	 * spin_lock to protect the per cgroup LRU
-	 */
-	struct list_head	lists[NR_LRU_LISTS];
+	struct lruvec		lruvec;
 	unsigned long		count[NR_LRU_LISTS];
 
 	struct mem_cgroup_reclaim_iter reclaim_iter[DEF_PRIORITY + 1];
@@ -995,7 +992,7 @@ void mem_cgroup_rotate_reclaimable_page(struct page *page)
 	/* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
 	smp_rmb();
 	mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
-	list_move_tail(&pc->lru, &mz->lists[lru]);
+	list_move_tail(&pc->lru, &mz->lruvec.lists[lru]);
 }
 
 void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
@@ -1013,7 +1010,7 @@ void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
 	/* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
 	smp_rmb();
 	mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
-	list_move(&pc->lru, &mz->lists[lru]);
+	list_move(&pc->lru, &mz->lruvec.lists[lru]);
 }
 
 void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
@@ -1043,7 +1040,7 @@ void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
 	/* huge page split is done under lru_lock. so, we have no races. */
 	MEM_CGROUP_ZSTAT(mz, lru) += 1 << compound_order(page);
 	SetPageCgroupAcctLRU(pc);
-	list_add(&pc->lru, &mz->lists[lru]);
+	list_add(&pc->lru, &mz->lruvec.lists[lru]);
 }
 
 /*
@@ -1241,7 +1238,7 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
 
 	BUG_ON(!mem_cont);
 	mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
-	src = &mz->lists[lru];
+	src = &mz->lruvec.lists[lru];
 
 	scan = 0;
 	list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
@@ -3628,7 +3625,7 @@ static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg,
 
 	zone = &NODE_DATA(node)->node_zones[zid];
 	mz = mem_cgroup_zoneinfo(memcg, node, zid);
-	list = &mz->lists[lru];
+	list = &mz->lruvec.lists[lru];
 
 	loop = MEM_CGROUP_ZSTAT(mz, lru);
 	/* give some margin against EBUSY etc...*/
@@ -4724,7 +4721,7 @@ static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
 	for (zone = 0; zone < MAX_NR_ZONES; zone++) {
 		mz = &pn->zoneinfo[zone];
 		for_each_lru(l)
-			INIT_LIST_HEAD(&mz->lists[l]);
+			INIT_LIST_HEAD(&mz->lruvec.lists[l]);
 		mz->usage_in_excess = 0;
 		mz->on_tree = false;
 		mz->mem = memcg;
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 9dd443d..9310f31 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4341,7 +4341,7 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat,
 
 		zone_pcp_init(zone);
 		for_each_lru(l)
-			INIT_LIST_HEAD(&zone->lru[l].list);
+			INIT_LIST_HEAD(&zone->lruvec.lists[l]);
 		zone->reclaim_stat.recent_rotated[0] = 0;
 		zone->reclaim_stat.recent_rotated[1] = 0;
 		zone->reclaim_stat.recent_scanned[0] = 0;
diff --git a/mm/swap.c b/mm/swap.c
index a91caf7..5de4443 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -236,7 +236,7 @@ static void pagevec_move_tail_fn(struct page *page, void *arg)
 
 	if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
 		enum lru_list lru = page_lru_base_type(page);
-		list_move_tail(&page->lru, &zone->lru[lru].list);
+		list_move_tail(&page->lru, &zone->lruvec.lists[lru]);
 		mem_cgroup_rotate_reclaimable_page(page);
 		(*pgmoved)++;
 	}
@@ -480,7 +480,7 @@ static void lru_deactivate_fn(struct page *page, void *arg)
 		 * The page's writeback ends up during pagevec
 		 * We moves tha page into tail of inactive.
 		 */
-		list_move_tail(&page->lru, &zone->lru[lru].list);
+		list_move_tail(&page->lru, &zone->lruvec.lists[lru]);
 		mem_cgroup_rotate_reclaimable_page(page);
 		__count_vm_event(PGROTATED);
 	}
@@ -662,7 +662,6 @@ void lru_add_page_tail(struct zone* zone,
 	int active;
 	enum lru_list lru;
 	const int file = 0;
-	struct list_head *head;
 
 	VM_BUG_ON(!PageHead(page));
 	VM_BUG_ON(PageCompound(page_tail));
@@ -682,10 +681,10 @@ void lru_add_page_tail(struct zone* zone,
 		}
 		update_page_reclaim_stat(zone, page_tail, file, active);
 		if (likely(PageLRU(page)))
-			head = page->lru.prev;
+			__add_page_to_lru_list(zone, page_tail, lru,
+					       page->lru.prev);
 		else
-			head = &zone->lru[lru].list;
-		__add_page_to_lru_list(zone, page_tail, lru, head);
+			add_page_to_lru_list(zone, page_tail, lru);
 	} else {
 		SetPageUnevictable(page_tail);
 		add_page_to_lru_list(zone, page_tail, LRU_UNEVICTABLE);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index e214e02..174deff 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1262,8 +1262,8 @@ static unsigned long isolate_pages_global(unsigned long nr,
 		lru += LRU_ACTIVE;
 	if (file)
 		lru += LRU_FILE;
-	return isolate_lru_pages(nr, &z->lru[lru].list, dst, scanned, order,
-								mode, file);
+	return isolate_lru_pages(nr, &z->lruvec.lists[lru], dst,
+				 scanned, order, mode, file);
 }
 
 /*
@@ -1642,7 +1642,7 @@ static void move_active_pages_to_lru(struct zone *zone,
 		VM_BUG_ON(PageLRU(page));
 		SetPageLRU(page);
 
-		list_move(&page->lru, &zone->lru[lru].list);
+		list_move(&page->lru, &zone->lruvec.lists[lru]);
 		mem_cgroup_add_lru_list(page, lru);
 		pgmoved += hpage_nr_pages(page);
 
@@ -3459,7 +3459,7 @@ retry:
 		enum lru_list l = page_lru_base_type(page);
 
 		__dec_zone_state(zone, NR_UNEVICTABLE);
-		list_move(&page->lru, &zone->lru[l].list);
+		list_move(&page->lru, &zone->lruvec.lists[l]);
 		mem_cgroup_move_lists(page, LRU_UNEVICTABLE, l);
 		__inc_zone_state(zone, NR_INACTIVE_ANON + l);
 		__count_vm_event(UNEVICTABLE_PGRESCUED);
@@ -3468,7 +3468,7 @@ retry:
 		 * rotate unevictable list
 		 */
 		SetPageUnevictable(page);
-		list_move(&page->lru, &zone->lru[LRU_UNEVICTABLE].list);
+		list_move(&page->lru, &zone->lruvec.lists[LRU_UNEVICTABLE]);
 		mem_cgroup_rotate_lru_list(page, LRU_UNEVICTABLE);
 		if (page_evictable(page, NULL))
 			goto retry;
-- 
1.7.6.4

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^ permalink raw reply related	[flat|nested] 32+ messages in thread
* [patch 09/10] mm: make per-memcg LRU lists exclusive
  2011-11-08 21:23 ` Johannes Weiner
@ 2011-11-08 21:23   ` Johannes Weiner
  -1 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-11-08 21:23 UTC (permalink / raw)
  To: Andrew Morton
  Cc: KAMEZAWA Hiroyuki, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel

Now that all code that operated on global per-zone LRU lists is
converted to operate on per-memory cgroup LRU lists instead, there is
no reason to keep the double-LRU scheme around any longer.

The pc->lru member is removed and page->lru is linked directly to the
per-memory cgroup LRU lists, which removes two pointers from a
descriptor that exists for every page frame in the system.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Ying Han <yinghan@google.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
---
 include/linux/memcontrol.h  |   51 +++----
 include/linux/mm_inline.h   |   21 +--
 include/linux/page_cgroup.h |    1 -
 mm/memcontrol.c             |  311 +++++++++++++++++++++----------------------
 mm/page_cgroup.c            |    1 -
 mm/swap.c                   |   23 ++-
 mm/vmscan.c                 |   64 ++++-----
 7 files changed, 225 insertions(+), 247 deletions(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 6952016..2bf7698 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -32,14 +32,6 @@ enum mem_cgroup_page_stat_item {
 	MEMCG_NR_FILE_MAPPED, /* # of pages charged as file rss */
 };
 
-extern unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
-					struct list_head *dst,
-					unsigned long *scanned, int order,
-					isolate_mode_t mode,
-					struct zone *z,
-					struct mem_cgroup *mem_cont,
-					int active, int file);
-
 struct mem_cgroup_reclaim_cookie {
 	struct zone *zone;
 	int priority;
@@ -69,13 +61,14 @@ extern void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *ptr);
 
 extern int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
 					gfp_t gfp_mask);
-extern void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru);
-extern void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru);
-extern void mem_cgroup_rotate_reclaimable_page(struct page *page);
-extern void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru);
-extern void mem_cgroup_del_lru(struct page *page);
-extern void mem_cgroup_move_lists(struct page *page,
-				  enum lru_list from, enum lru_list to);
+
+struct lruvec *mem_cgroup_zone_lruvec(struct zone *, struct mem_cgroup *);
+struct lruvec *mem_cgroup_lru_add_list(struct zone *, struct page *,
+				       enum lru_list);
+void mem_cgroup_lru_del_list(struct page *, enum lru_list);
+void mem_cgroup_lru_del(struct page *);
+struct lruvec *mem_cgroup_lru_move_lists(struct zone *, struct page *,
+					 enum lru_list, enum lru_list);
 
 /* For coalescing uncharge for reducing memcg' overhead*/
 extern void mem_cgroup_uncharge_start(void);
@@ -218,33 +211,33 @@ static inline void mem_cgroup_uncharge_cache_page(struct page *page)
 {
 }
 
-static inline void mem_cgroup_add_lru_list(struct page *page, int lru)
-{
-}
-
-static inline void mem_cgroup_del_lru_list(struct page *page, int lru)
+static inline struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
+						    struct mem_cgroup *memcg)
 {
-	return ;
+	return &zone->lruvec;
 }
 
-static inline void mem_cgroup_rotate_reclaimable_page(struct page *page)
+static inline struct lruvec *mem_cgroup_lru_add_list(struct zone *zone,
+						     struct page *page,
+						     enum lru_list lru)
 {
-	return ;
+	return &zone->lruvec;
 }
 
-static inline void mem_cgroup_rotate_lru_list(struct page *page, int lru)
+static inline void mem_cgroup_lru_del_list(struct page *page, enum lru_list lru)
 {
-	return ;
 }
 
-static inline void mem_cgroup_del_lru(struct page *page)
+static inline void mem_cgroup_lru_del(struct page *page)
 {
-	return ;
 }
 
-static inline void
-mem_cgroup_move_lists(struct page *page, enum lru_list from, enum lru_list to)
+static inline struct lruvec *mem_cgroup_lru_move_lists(struct zone *zone,
+						       struct page *page,
+						       enum lru_list from,
+						       enum lru_list to)
 {
+	return &zone->lruvec;
 }
 
 static inline struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
index e6a7ffe..4e3478e 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -22,26 +22,21 @@ static inline int page_is_file_cache(struct page *page)
 }
 
 static inline void
-__add_page_to_lru_list(struct zone *zone, struct page *page, enum lru_list l,
-		       struct list_head *head)
-{
-	list_add(&page->lru, head);
-	__mod_zone_page_state(zone, NR_LRU_BASE + l, hpage_nr_pages(page));
-	mem_cgroup_add_lru_list(page, l);
-}
-
-static inline void
 add_page_to_lru_list(struct zone *zone, struct page *page, enum lru_list l)
 {
-	__add_page_to_lru_list(zone, page, l, &zone->lruvec.lists[l]);
+	struct lruvec *lruvec;
+
+	lruvec = mem_cgroup_lru_add_list(zone, page, l);
+	list_add(&page->lru, &lruvec->lists[l]);
+	__mod_zone_page_state(zone, NR_LRU_BASE + l, hpage_nr_pages(page));
 }
 
 static inline void
 del_page_from_lru_list(struct zone *zone, struct page *page, enum lru_list l)
 {
+	mem_cgroup_lru_del_list(page, l);
 	list_del(&page->lru);
 	__mod_zone_page_state(zone, NR_LRU_BASE + l, -hpage_nr_pages(page));
-	mem_cgroup_del_lru_list(page, l);
 }
 
 /**
@@ -64,7 +59,6 @@ del_page_from_lru(struct zone *zone, struct page *page)
 {
 	enum lru_list l;
 
-	list_del(&page->lru);
 	if (PageUnevictable(page)) {
 		__ClearPageUnevictable(page);
 		l = LRU_UNEVICTABLE;
@@ -75,8 +69,9 @@ del_page_from_lru(struct zone *zone, struct page *page)
 			l += LRU_ACTIVE;
 		}
 	}
+	mem_cgroup_lru_del_list(page, l);
+	list_del(&page->lru);
 	__mod_zone_page_state(zone, NR_LRU_BASE + l, -hpage_nr_pages(page));
-	mem_cgroup_del_lru_list(page, l);
 }
 
 /**
diff --git a/include/linux/page_cgroup.h b/include/linux/page_cgroup.h
index 961ecc7..5bae753 100644
--- a/include/linux/page_cgroup.h
+++ b/include/linux/page_cgroup.h
@@ -31,7 +31,6 @@ enum {
 struct page_cgroup {
 	unsigned long flags;
 	struct mem_cgroup *mem_cgroup;
-	struct list_head lru;		/* per cgroup LRU list */
 };
 
 void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 22f25b0..02c36ee 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -929,6 +929,27 @@ out:
 }
 EXPORT_SYMBOL(mem_cgroup_count_vm_event);
 
+/**
+ * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
+ * @zone: zone of the wanted lruvec
+ * @mem: memcg of the wanted lruvec
+ *
+ * Returns the lru list vector holding pages for the given @zone and
+ * @mem.  This can be the global zone lruvec, if the memory controller
+ * is disabled.
+ */
+struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
+				      struct mem_cgroup *memcg)
+{
+	struct mem_cgroup_per_zone *mz;
+
+	if (mem_cgroup_disabled())
+		return &zone->lruvec;
+
+	mz = mem_cgroup_zoneinfo(memcg, zone_to_nid(zone), zone_idx(zone));
+	return &mz->lruvec;
+}
+
 /*
  * Following LRU functions are allowed to be used without PCG_LOCK.
  * Operations are called by routine of global LRU independently from memcg.
@@ -943,104 +964,123 @@ EXPORT_SYMBOL(mem_cgroup_count_vm_event);
  * When moving account, the page is not on LRU. It's isolated.
  */
 
-void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru)
+/**
+ * mem_cgroup_lru_add_list - account for adding an lru page and return lruvec
+ * @zone: zone of the page
+ * @page: the page
+ * @lru: current lru
+ *
+ * This function accounts for @page being added to @lru, and returns
+ * the lruvec for the given @zone and the memcg @page is charged to.
+ *
+ * The callsite is then responsible for physically linking the page to
+ * the returned lruvec->lists[@lru].
+ */
+struct lruvec *mem_cgroup_lru_add_list(struct zone *zone, struct page *page,
+				       enum lru_list lru)
 {
-	struct page_cgroup *pc;
 	struct mem_cgroup_per_zone *mz;
+	struct mem_cgroup *memcg;
+	struct page_cgroup *pc;
 
 	if (mem_cgroup_disabled())
-		return;
+		return &zone->lruvec;
+
 	pc = lookup_page_cgroup(page);
-	/* can happen while we handle swapcache. */
-	if (!TestClearPageCgroupAcctLRU(pc))
-		return;
-	VM_BUG_ON(!pc->mem_cgroup);
+	VM_BUG_ON(PageCgroupAcctLRU(pc));
 	/*
-	 * We don't check PCG_USED bit. It's cleared when the "page" is finally
-	 * removed from global LRU.
+	 * putback:				charge:
+	 * SetPageLRU				SetPageCgroupUsed
+	 * smp_mb				smp_mb
+	 * PageCgroupUsed && add to memcg LRU	PageLRU && add to memcg LRU
+	 *
+	 * Ensure that one of the two sides adds the page to the memcg
+	 * LRU during a race.
 	 */
-	mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
-	/* huge page split is done under lru_lock. so, we have no races. */
-	MEM_CGROUP_ZSTAT(mz, lru) -= 1 << compound_order(page);
-	VM_BUG_ON(list_empty(&pc->lru));
-	list_del_init(&pc->lru);
-}
-
-void mem_cgroup_del_lru(struct page *page)
-{
-	mem_cgroup_del_lru_list(page, page_lru(page));
+	smp_mb();
+	/*
+	 * If the page is uncharged, it may be freed soon, but it
+	 * could also be swap cache (readahead, swapoff) that needs to
+	 * be reclaimable in the future.  root_mem_cgroup will babysit
+	 * it for the time being.
+	 */
+	if (PageCgroupUsed(pc)) {
+		/* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
+		smp_rmb();
+		memcg = pc->mem_cgroup;
+		SetPageCgroupAcctLRU(pc);
+	} else
+		memcg = root_mem_cgroup;
+	mz = page_cgroup_zoneinfo(memcg, page);
+	/* compound_order() is stabilized through lru_lock */
+	MEM_CGROUP_ZSTAT(mz, lru) += 1 << compound_order(page);
+	return &mz->lruvec;
 }
 
-/*
- * Writeback is about to end against a page which has been marked for immediate
- * reclaim.  If it still appears to be reclaimable, move it to the tail of the
- * inactive list.
+/**
+ * mem_cgroup_lru_del_list - account for removing an lru page
+ * @page: the page
+ * @lru: target lru
+ *
+ * This function accounts for @page being removed from @lru.
+ *
+ * The callsite is then responsible for physically unlinking
+ * @page->lru.
  */
-void mem_cgroup_rotate_reclaimable_page(struct page *page)
+void mem_cgroup_lru_del_list(struct page *page, enum lru_list lru)
 {
 	struct mem_cgroup_per_zone *mz;
+	struct mem_cgroup *memcg;
 	struct page_cgroup *pc;
-	enum lru_list lru = page_lru(page);
 
 	if (mem_cgroup_disabled())
 		return;
 
 	pc = lookup_page_cgroup(page);
-	/* unused page is not rotated. */
-	if (!PageCgroupUsed(pc))
-		return;
-	/* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
-	smp_rmb();
-	mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
-	list_move_tail(&pc->lru, &mz->lruvec.lists[lru]);
+	/*
+	 * root_mem_cgroup babysits uncharged LRU pages, but
+	 * PageCgroupUsed is cleared when the page is about to get
+	 * freed.  PageCgroupAcctLRU remembers whether the
+	 * LRU-accounting happened against pc->mem_cgroup or
+	 * root_mem_cgroup.
+	 */
+	if (TestClearPageCgroupAcctLRU(pc)) {
+		VM_BUG_ON(!pc->mem_cgroup);
+		memcg = pc->mem_cgroup;
+	} else
+		memcg = root_mem_cgroup;
+	mz = page_cgroup_zoneinfo(memcg, page);
+	/* huge page split is done under lru_lock. so, we have no races. */
+	MEM_CGROUP_ZSTAT(mz, lru) -= 1 << compound_order(page);
 }
 
-void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
+void mem_cgroup_lru_del(struct page *page)
 {
-	struct mem_cgroup_per_zone *mz;
-	struct page_cgroup *pc;
-
-	if (mem_cgroup_disabled())
-		return;
-
-	pc = lookup_page_cgroup(page);
-	/* unused page is not rotated. */
-	if (!PageCgroupUsed(pc))
-		return;
-	/* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
-	smp_rmb();
-	mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
-	list_move(&pc->lru, &mz->lruvec.lists[lru]);
+	mem_cgroup_lru_del_list(page, page_lru(page));
 }
 
-void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
+/**
+ * mem_cgroup_lru_move_lists - account for moving a page between lrus
+ * @zone: zone of the page
+ * @page: the page
+ * @from: current lru
+ * @to: target lru
+ *
+ * This function accounts for @page being moved between the lrus @from
+ * and @to, and returns the lruvec for the given @zone and the memcg
+ * @page is charged to.
+ *
+ * The callsite is then responsible for physically relinking
+ * @page->lru to the returned lruvec->lists[@to].
+ */
+struct lruvec *mem_cgroup_lru_move_lists(struct zone *zone,
+					 struct page *page,
+					 enum lru_list from,
+					 enum lru_list to)
 {
-	struct page_cgroup *pc;
-	struct mem_cgroup_per_zone *mz;
-
-	if (mem_cgroup_disabled())
-		return;
-	pc = lookup_page_cgroup(page);
-	VM_BUG_ON(PageCgroupAcctLRU(pc));
-	/*
-	 * putback:				charge:
-	 * SetPageLRU				SetPageCgroupUsed
-	 * smp_mb				smp_mb
-	 * PageCgroupUsed && add to memcg LRU	PageLRU && add to memcg LRU
-	 *
-	 * Ensure that one of the two sides adds the page to the memcg
-	 * LRU during a race.
-	 */
-	smp_mb();
-	if (!PageCgroupUsed(pc))
-		return;
-	/* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
-	smp_rmb();
-	mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
-	/* huge page split is done under lru_lock. so, we have no races. */
-	MEM_CGROUP_ZSTAT(mz, lru) += 1 << compound_order(page);
-	SetPageCgroupAcctLRU(pc);
-	list_add(&pc->lru, &mz->lruvec.lists[lru]);
+	/* XXX: Optimize this, especially for @from == @to */
+	mem_cgroup_lru_del_list(page, from);
+	return mem_cgroup_lru_add_list(zone, page, to);
 }
 
 /*
@@ -1051,6 +1091,7 @@ void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
  */
 static void mem_cgroup_lru_del_before_commit(struct page *page)
 {
+	enum lru_list lru;
 	unsigned long flags;
 	struct zone *zone = page_zone(page);
 	struct page_cgroup *pc = lookup_page_cgroup(page);
@@ -1067,17 +1108,28 @@ static void mem_cgroup_lru_del_before_commit(struct page *page)
 		return;
 
 	spin_lock_irqsave(&zone->lru_lock, flags);
+	lru = page_lru(page);
 	/*
-	 * Forget old LRU when this page_cgroup is *not* used. This Used bit
-	 * is guarded by lock_page() because the page is SwapCache.
+	 * The uncharged page could still be registered to the LRU of
+	 * the stale pc->mem_cgroup.
+	 *
+	 * As pc->mem_cgroup is about to get overwritten, the old LRU
+	 * accounting needs to be taken care of.  Let root_mem_cgroup
+	 * babysit the page until the new memcg is responsible for it.
+	 *
+	 * The PCG_USED bit is guarded by lock_page() as the page is
+	 * swapcache/pagecache.
 	 */
-	if (!PageCgroupUsed(pc))
-		mem_cgroup_del_lru_list(page, page_lru(page));
+	if (PageLRU(page) && PageCgroupAcctLRU(pc) && !PageCgroupUsed(pc)) {
+		del_page_from_lru_list(zone, page, lru);
+		add_page_to_lru_list(zone, page, lru);
+	}
 	spin_unlock_irqrestore(&zone->lru_lock, flags);
 }
 
 static void mem_cgroup_lru_add_after_commit(struct page *page)
 {
+	enum lru_list lru;
 	unsigned long flags;
 	struct zone *zone = page_zone(page);
 	struct page_cgroup *pc = lookup_page_cgroup(page);
@@ -1095,22 +1147,22 @@ static void mem_cgroup_lru_add_after_commit(struct page *page)
 	if (likely(!PageLRU(page)))
 		return;
 	spin_lock_irqsave(&zone->lru_lock, flags);
-	/* link when the page is linked to LRU but page_cgroup isn't */
-	if (PageLRU(page) && !PageCgroupAcctLRU(pc))
-		mem_cgroup_add_lru_list(page, page_lru(page));
+	lru = page_lru(page);
+	/*
+	 * If the page is not on the LRU, someone will soon put it
+	 * there.  If it is, and also already accounted for on the
+	 * memcg-side, it must be on the right lruvec as setting
+	 * pc->mem_cgroup and PageCgroupUsed is properly ordered.
+	 * Otherwise, root_mem_cgroup has been babysitting the page
+	 * during the charge.  Move it to the new memcg now.
+	 */
+	if (PageLRU(page) && !PageCgroupAcctLRU(pc)) {
+		del_page_from_lru_list(zone, page, lru);
+		add_page_to_lru_list(zone, page, lru);
+	}
 	spin_unlock_irqrestore(&zone->lru_lock, flags);
 }
 
-
-void mem_cgroup_move_lists(struct page *page,
-			   enum lru_list from, enum lru_list to)
-{
-	if (mem_cgroup_disabled())
-		return;
-	mem_cgroup_del_lru_list(page, from);
-	mem_cgroup_add_lru_list(page, to);
-}
-
 /*
  * Checks whether given mem is same or in the root_mem_cgroup's
  * hierarchy subtree
@@ -1216,68 +1268,6 @@ mem_cgroup_get_reclaim_stat_from_page(struct page *page)
 	return &mz->reclaim_stat;
 }
 
-unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
-					struct list_head *dst,
-					unsigned long *scanned, int order,
-					isolate_mode_t mode,
-					struct zone *z,
-					struct mem_cgroup *mem_cont,
-					int active, int file)
-{
-	unsigned long nr_taken = 0;
-	struct page *page;
-	unsigned long scan;
-	LIST_HEAD(pc_list);
-	struct list_head *src;
-	struct page_cgroup *pc, *tmp;
-	int nid = zone_to_nid(z);
-	int zid = zone_idx(z);
-	struct mem_cgroup_per_zone *mz;
-	int lru = LRU_FILE * file + active;
-	int ret;
-
-	BUG_ON(!mem_cont);
-	mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
-	src = &mz->lruvec.lists[lru];
-
-	scan = 0;
-	list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
-		if (scan >= nr_to_scan)
-			break;
-
-		if (unlikely(!PageCgroupUsed(pc)))
-			continue;
-
-		page = lookup_cgroup_page(pc);
-
-		if (unlikely(!PageLRU(page)))
-			continue;
-
-		scan++;
-		ret = __isolate_lru_page(page, mode, file);
-		switch (ret) {
-		case 0:
-			list_move(&page->lru, dst);
-			mem_cgroup_del_lru(page);
-			nr_taken += hpage_nr_pages(page);
-			break;
-		case -EBUSY:
-			/* we don't affect global LRU but rotate in our LRU */
-			mem_cgroup_rotate_lru_list(page, page_lru(page));
-			break;
-		default:
-			break;
-		}
-	}
-
-	*scanned = scan;
-
-	trace_mm_vmscan_memcg_isolate(0, nr_to_scan, scan, nr_taken,
-				      0, 0, 0, mode);
-
-	return nr_taken;
-}
-
 #define mem_cgroup_from_res_counter(counter, member)	\
 	container_of(counter, struct mem_cgroup, member)
 
@@ -3616,11 +3606,11 @@ unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
 static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg,
 				int node, int zid, enum lru_list lru)
 {
-	struct zone *zone;
 	struct mem_cgroup_per_zone *mz;
-	struct page_cgroup *pc, *busy;
 	unsigned long flags, loop;
 	struct list_head *list;
+	struct page *busy;
+	struct zone *zone;
 	int ret = 0;
 
 	zone = &NODE_DATA(node)->node_zones[zid];
@@ -3632,6 +3622,7 @@ static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg,
 	loop += 256;
 	busy = NULL;
 	while (loop--) {
+		struct page_cgroup *pc;
 		struct page *page;
 
 		ret = 0;
@@ -3640,16 +3631,16 @@ static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg,
 			spin_unlock_irqrestore(&zone->lru_lock, flags);
 			break;
 		}
-		pc = list_entry(list->prev, struct page_cgroup, lru);
-		if (busy == pc) {
-			list_move(&pc->lru, list);
+		page = list_entry(list->prev, struct page, lru);
+		if (busy == page) {
+			list_move(&page->lru, list);
 			busy = NULL;
 			spin_unlock_irqrestore(&zone->lru_lock, flags);
 			continue;
 		}
 		spin_unlock_irqrestore(&zone->lru_lock, flags);
 
-		page = lookup_cgroup_page(pc);
+		pc = lookup_page_cgroup(page);
 
 		ret = mem_cgroup_move_parent(page, pc, memcg, GFP_KERNEL);
 		if (ret == -ENOMEM)
@@ -3657,7 +3648,7 @@ static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg,
 
 		if (ret == -EBUSY || ret == -EINVAL) {
 			/* found lock contention or "pc" is obsolete. */
-			busy = pc;
+			busy = page;
 			cond_resched();
 		} else
 			busy = NULL;
diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index 2d123f9..f59405a 100644
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -16,7 +16,6 @@ static void __meminit init_page_cgroup(struct page_cgroup *pc, unsigned long id)
 	pc->flags = 0;
 	set_page_cgroup_array_id(pc, id);
 	pc->mem_cgroup = NULL;
-	INIT_LIST_HEAD(&pc->lru);
 }
 static unsigned long total_usage;
 
diff --git a/mm/swap.c b/mm/swap.c
index 5de4443..5fb3b94 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -232,12 +232,14 @@ static void pagevec_lru_move_fn(struct pagevec *pvec,
 static void pagevec_move_tail_fn(struct page *page, void *arg)
 {
 	int *pgmoved = arg;
-	struct zone *zone = page_zone(page);
 
 	if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
 		enum lru_list lru = page_lru_base_type(page);
-		list_move_tail(&page->lru, &zone->lruvec.lists[lru]);
-		mem_cgroup_rotate_reclaimable_page(page);
+		struct lruvec *lruvec;
+
+		lruvec = mem_cgroup_lru_move_lists(page_zone(page),
+						   page, lru, lru);
+		list_move_tail(&page->lru, &lruvec->lists[lru]);
 		(*pgmoved)++;
 	}
 }
@@ -476,12 +478,13 @@ static void lru_deactivate_fn(struct page *page, void *arg)
 		 */
 		SetPageReclaim(page);
 	} else {
+		struct lruvec *lruvec;
 		/*
 		 * The page's writeback ends up during pagevec
 		 * We moves tha page into tail of inactive.
 		 */
-		list_move_tail(&page->lru, &zone->lruvec.lists[lru]);
-		mem_cgroup_rotate_reclaimable_page(page);
+		lruvec = mem_cgroup_lru_move_lists(zone, page, lru, lru);
+		list_move_tail(&page->lru, &lruvec->lists[lru]);
 		__count_vm_event(PGROTATED);
 	}
 
@@ -671,6 +674,8 @@ void lru_add_page_tail(struct zone* zone,
 	SetPageLRU(page_tail);
 
 	if (page_evictable(page_tail, NULL)) {
+		struct lruvec *lruvec;
+
 		if (PageActive(page)) {
 			SetPageActive(page_tail);
 			active = 1;
@@ -680,11 +685,13 @@ void lru_add_page_tail(struct zone* zone,
 			lru = LRU_INACTIVE_ANON;
 		}
 		update_page_reclaim_stat(zone, page_tail, file, active);
+		lruvec = mem_cgroup_lru_add_list(zone, page_tail, lru);
 		if (likely(PageLRU(page)))
-			__add_page_to_lru_list(zone, page_tail, lru,
-					       page->lru.prev);
+			list_add(&page_tail->lru, page->lru.prev);
 		else
-			add_page_to_lru_list(zone, page_tail, lru);
+			list_add(&page_tail->lru, &lruvec->lists[lru]);
+		__mod_zone_page_state(zone, NR_LRU_BASE + lru,
+				      hpage_nr_pages(page_tail));
 	} else {
 		SetPageUnevictable(page_tail);
 		add_page_to_lru_list(zone, page_tail, LRU_UNEVICTABLE);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 174deff..21ce3cb 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1151,15 +1151,14 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
 
 		switch (__isolate_lru_page(page, mode, file)) {
 		case 0:
+			mem_cgroup_lru_del(page);
 			list_move(&page->lru, dst);
-			mem_cgroup_del_lru(page);
 			nr_taken += hpage_nr_pages(page);
 			break;
 
 		case -EBUSY:
 			/* else it is being freed elsewhere */
 			list_move(&page->lru, src);
-			mem_cgroup_rotate_lru_list(page, page_lru(page));
 			continue;
 
 		default:
@@ -1209,8 +1208,8 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
 				break;
 
 			if (__isolate_lru_page(cursor_page, mode, file) == 0) {
+				mem_cgroup_lru_del(cursor_page);
 				list_move(&cursor_page->lru, dst);
-				mem_cgroup_del_lru(cursor_page);
 				nr_taken += hpage_nr_pages(page);
 				nr_lumpy_taken++;
 				if (PageDirty(cursor_page))
@@ -1251,18 +1250,20 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
 	return nr_taken;
 }
 
-static unsigned long isolate_pages_global(unsigned long nr,
-					struct list_head *dst,
-					unsigned long *scanned, int order,
-					isolate_mode_t mode,
-					struct zone *z,	int active, int file)
+static unsigned long isolate_pages(unsigned long nr, struct mem_cgroup_zone *mz,
+				   struct list_head *dst,
+				   unsigned long *scanned, int order,
+				   isolate_mode_t mode, int active, int file)
 {
+	struct lruvec *lruvec;
 	int lru = LRU_BASE;
+
+	lruvec = mem_cgroup_zone_lruvec(mz->zone, mz->mem_cgroup);
 	if (active)
 		lru += LRU_ACTIVE;
 	if (file)
 		lru += LRU_FILE;
-	return isolate_lru_pages(nr, &z->lruvec.lists[lru], dst,
+	return isolate_lru_pages(nr, &lruvec->lists[lru], dst,
 				 scanned, order, mode, file);
 }
 
@@ -1530,14 +1531,9 @@ shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz,
 
 	spin_lock_irq(&zone->lru_lock);
 
-	if (scanning_global_lru(mz)) {
-		nr_taken = isolate_pages_global(nr_to_scan, &page_list,
-			&nr_scanned, sc->order, reclaim_mode, zone, 0, file);
-	} else {
-		nr_taken = mem_cgroup_isolate_pages(nr_to_scan, &page_list,
-			&nr_scanned, sc->order, reclaim_mode, zone,
-			mz->mem_cgroup, 0, file);
-	}
+	nr_taken = isolate_pages(nr_to_scan, mz, &page_list,
+				 &nr_scanned, sc->order,
+				 reclaim_mode, 0, file);
 	if (global_reclaim(sc)) {
 		zone->pages_scanned += nr_scanned;
 		if (current_is_kswapd())
@@ -1637,13 +1633,15 @@ static void move_active_pages_to_lru(struct zone *zone,
 	pagevec_init(&pvec, 1);
 
 	while (!list_empty(list)) {
+		struct lruvec *lruvec;
+
 		page = lru_to_page(list);
 
 		VM_BUG_ON(PageLRU(page));
 		SetPageLRU(page);
 
-		list_move(&page->lru, &zone->lruvec.lists[lru]);
-		mem_cgroup_add_lru_list(page, lru);
+		lruvec = mem_cgroup_lru_add_list(zone, page, lru);
+		list_move(&page->lru, &lruvec->lists[lru]);
 		pgmoved += hpage_nr_pages(page);
 
 		if (!pagevec_add(&pvec, page) || list_empty(list)) {
@@ -1684,17 +1682,10 @@ static void shrink_active_list(unsigned long nr_pages,
 		reclaim_mode |= ISOLATE_CLEAN;
 
 	spin_lock_irq(&zone->lru_lock);
-	if (scanning_global_lru(mz)) {
-		nr_taken = isolate_pages_global(nr_pages, &l_hold,
-						&pgscanned, sc->order,
-						reclaim_mode, zone,
-						1, file);
-	} else {
-		nr_taken = mem_cgroup_isolate_pages(nr_pages, &l_hold,
-						&pgscanned, sc->order,
-						reclaim_mode, zone,
-						mz->mem_cgroup, 1, file);
-	}
+
+	nr_taken = isolate_pages(nr_pages, mz, &l_hold,
+				 &pgscanned, sc->order,
+				 reclaim_mode, 1, file);
 
 	if (global_reclaim(sc))
 		zone->pages_scanned += pgscanned;
@@ -3451,16 +3442,18 @@ int page_evictable(struct page *page, struct vm_area_struct *vma)
  */
 static void check_move_unevictable_page(struct page *page, struct zone *zone)
 {
-	VM_BUG_ON(PageActive(page));
+	struct lruvec *lruvec;
 
+	VM_BUG_ON(PageActive(page));
 retry:
 	ClearPageUnevictable(page);
 	if (page_evictable(page, NULL)) {
 		enum lru_list l = page_lru_base_type(page);
 
 		__dec_zone_state(zone, NR_UNEVICTABLE);
-		list_move(&page->lru, &zone->lruvec.lists[l]);
-		mem_cgroup_move_lists(page, LRU_UNEVICTABLE, l);
+		lruvec = mem_cgroup_lru_move_lists(zone, page,
+						   LRU_UNEVICTABLE, l);
+		list_move(&page->lru, &lruvec->lists[l]);
 		__inc_zone_state(zone, NR_INACTIVE_ANON + l);
 		__count_vm_event(UNEVICTABLE_PGRESCUED);
 	} else {
@@ -3468,8 +3461,9 @@ retry:
 		 * rotate unevictable list
 		 */
 		SetPageUnevictable(page);
-		list_move(&page->lru, &zone->lruvec.lists[LRU_UNEVICTABLE]);
-		mem_cgroup_rotate_lru_list(page, LRU_UNEVICTABLE);
+		lruvec = mem_cgroup_lru_move_lists(zone, page, LRU_UNEVICTABLE,
+						   LRU_UNEVICTABLE);
+		list_move(&page->lru, &lruvec->lists[LRU_UNEVICTABLE]);
 		if (page_evictable(page, NULL))
 			goto retry;
 	}
-- 
1.7.6.4


^ permalink raw reply related	[flat|nested] 32+ messages in thread
* [patch 09/10] mm: make per-memcg LRU lists exclusive
@ 2011-11-08 21:23   ` Johannes Weiner
  0 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-11-08 21:23 UTC (permalink / raw)
  To: Andrew Morton
  Cc: KAMEZAWA Hiroyuki, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel

Now that all code that operated on global per-zone LRU lists is
converted to operate on per-memory cgroup LRU lists instead, there is
no reason to keep the double-LRU scheme around any longer.

The pc->lru member is removed and page->lru is linked directly to the
per-memory cgroup LRU lists, which removes two pointers from a
descriptor that exists for every page frame in the system.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Ying Han <yinghan@google.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
---
 include/linux/memcontrol.h  |   51 +++----
 include/linux/mm_inline.h   |   21 +--
 include/linux/page_cgroup.h |    1 -
 mm/memcontrol.c             |  311 +++++++++++++++++++++----------------------
 mm/page_cgroup.c            |    1 -
 mm/swap.c                   |   23 ++-
 mm/vmscan.c                 |   64 ++++-----
 7 files changed, 225 insertions(+), 247 deletions(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 6952016..2bf7698 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -32,14 +32,6 @@ enum mem_cgroup_page_stat_item {
 	MEMCG_NR_FILE_MAPPED, /* # of pages charged as file rss */
 };
 
-extern unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
-					struct list_head *dst,
-					unsigned long *scanned, int order,
-					isolate_mode_t mode,
-					struct zone *z,
-					struct mem_cgroup *mem_cont,
-					int active, int file);
-
 struct mem_cgroup_reclaim_cookie {
 	struct zone *zone;
 	int priority;
@@ -69,13 +61,14 @@ extern void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *ptr);
 
 extern int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
 					gfp_t gfp_mask);
-extern void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru);
-extern void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru);
-extern void mem_cgroup_rotate_reclaimable_page(struct page *page);
-extern void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru);
-extern void mem_cgroup_del_lru(struct page *page);
-extern void mem_cgroup_move_lists(struct page *page,
-				  enum lru_list from, enum lru_list to);
+
+struct lruvec *mem_cgroup_zone_lruvec(struct zone *, struct mem_cgroup *);
+struct lruvec *mem_cgroup_lru_add_list(struct zone *, struct page *,
+				       enum lru_list);
+void mem_cgroup_lru_del_list(struct page *, enum lru_list);
+void mem_cgroup_lru_del(struct page *);
+struct lruvec *mem_cgroup_lru_move_lists(struct zone *, struct page *,
+					 enum lru_list, enum lru_list);
 
 /* For coalescing uncharge for reducing memcg' overhead*/
 extern void mem_cgroup_uncharge_start(void);
@@ -218,33 +211,33 @@ static inline void mem_cgroup_uncharge_cache_page(struct page *page)
 {
 }
 
-static inline void mem_cgroup_add_lru_list(struct page *page, int lru)
-{
-}
-
-static inline void mem_cgroup_del_lru_list(struct page *page, int lru)
+static inline struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
+						    struct mem_cgroup *memcg)
 {
-	return ;
+	return &zone->lruvec;
 }
 
-static inline void mem_cgroup_rotate_reclaimable_page(struct page *page)
+static inline struct lruvec *mem_cgroup_lru_add_list(struct zone *zone,
+						     struct page *page,
+						     enum lru_list lru)
 {
-	return ;
+	return &zone->lruvec;
 }
 
-static inline void mem_cgroup_rotate_lru_list(struct page *page, int lru)
+static inline void mem_cgroup_lru_del_list(struct page *page, enum lru_list lru)
 {
-	return ;
 }
 
-static inline void mem_cgroup_del_lru(struct page *page)
+static inline void mem_cgroup_lru_del(struct page *page)
 {
-	return ;
 }
 
-static inline void
-mem_cgroup_move_lists(struct page *page, enum lru_list from, enum lru_list to)
+static inline struct lruvec *mem_cgroup_lru_move_lists(struct zone *zone,
+						       struct page *page,
+						       enum lru_list from,
+						       enum lru_list to)
 {
+	return &zone->lruvec;
 }
 
 static inline struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
index e6a7ffe..4e3478e 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -22,26 +22,21 @@ static inline int page_is_file_cache(struct page *page)
 }
 
 static inline void
-__add_page_to_lru_list(struct zone *zone, struct page *page, enum lru_list l,
-		       struct list_head *head)
-{
-	list_add(&page->lru, head);
-	__mod_zone_page_state(zone, NR_LRU_BASE + l, hpage_nr_pages(page));
-	mem_cgroup_add_lru_list(page, l);
-}
-
-static inline void
 add_page_to_lru_list(struct zone *zone, struct page *page, enum lru_list l)
 {
-	__add_page_to_lru_list(zone, page, l, &zone->lruvec.lists[l]);
+	struct lruvec *lruvec;
+
+	lruvec = mem_cgroup_lru_add_list(zone, page, l);
+	list_add(&page->lru, &lruvec->lists[l]);
+	__mod_zone_page_state(zone, NR_LRU_BASE + l, hpage_nr_pages(page));
 }
 
 static inline void
 del_page_from_lru_list(struct zone *zone, struct page *page, enum lru_list l)
 {
+	mem_cgroup_lru_del_list(page, l);
 	list_del(&page->lru);
 	__mod_zone_page_state(zone, NR_LRU_BASE + l, -hpage_nr_pages(page));
-	mem_cgroup_del_lru_list(page, l);
 }
 
 /**
@@ -64,7 +59,6 @@ del_page_from_lru(struct zone *zone, struct page *page)
 {
 	enum lru_list l;
 
-	list_del(&page->lru);
 	if (PageUnevictable(page)) {
 		__ClearPageUnevictable(page);
 		l = LRU_UNEVICTABLE;
@@ -75,8 +69,9 @@ del_page_from_lru(struct zone *zone, struct page *page)
 			l += LRU_ACTIVE;
 		}
 	}
+	mem_cgroup_lru_del_list(page, l);
+	list_del(&page->lru);
 	__mod_zone_page_state(zone, NR_LRU_BASE + l, -hpage_nr_pages(page));
-	mem_cgroup_del_lru_list(page, l);
 }
 
 /**
diff --git a/include/linux/page_cgroup.h b/include/linux/page_cgroup.h
index 961ecc7..5bae753 100644
--- a/include/linux/page_cgroup.h
+++ b/include/linux/page_cgroup.h
@@ -31,7 +31,6 @@ enum {
 struct page_cgroup {
 	unsigned long flags;
 	struct mem_cgroup *mem_cgroup;
-	struct list_head lru;		/* per cgroup LRU list */
 };
 
 void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 22f25b0..02c36ee 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -929,6 +929,27 @@ out:
 }
 EXPORT_SYMBOL(mem_cgroup_count_vm_event);
 
+/**
+ * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
+ * @zone: zone of the wanted lruvec
+ * @mem: memcg of the wanted lruvec
+ *
+ * Returns the lru list vector holding pages for the given @zone and
+ * @mem.  This can be the global zone lruvec, if the memory controller
+ * is disabled.
+ */
+struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
+				      struct mem_cgroup *memcg)
+{
+	struct mem_cgroup_per_zone *mz;
+
+	if (mem_cgroup_disabled())
+		return &zone->lruvec;
+
+	mz = mem_cgroup_zoneinfo(memcg, zone_to_nid(zone), zone_idx(zone));
+	return &mz->lruvec;
+}
+
 /*
  * Following LRU functions are allowed to be used without PCG_LOCK.
  * Operations are called by routine of global LRU independently from memcg.
@@ -943,104 +964,123 @@ EXPORT_SYMBOL(mem_cgroup_count_vm_event);
  * When moving account, the page is not on LRU. It's isolated.
  */
 
-void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru)
+/**
+ * mem_cgroup_lru_add_list - account for adding an lru page and return lruvec
+ * @zone: zone of the page
+ * @page: the page
+ * @lru: current lru
+ *
+ * This function accounts for @page being added to @lru, and returns
+ * the lruvec for the given @zone and the memcg @page is charged to.
+ *
+ * The callsite is then responsible for physically linking the page to
+ * the returned lruvec->lists[@lru].
+ */
+struct lruvec *mem_cgroup_lru_add_list(struct zone *zone, struct page *page,
+				       enum lru_list lru)
 {
-	struct page_cgroup *pc;
 	struct mem_cgroup_per_zone *mz;
+	struct mem_cgroup *memcg;
+	struct page_cgroup *pc;
 
 	if (mem_cgroup_disabled())
-		return;
+		return &zone->lruvec;
+
 	pc = lookup_page_cgroup(page);
-	/* can happen while we handle swapcache. */
-	if (!TestClearPageCgroupAcctLRU(pc))
-		return;
-	VM_BUG_ON(!pc->mem_cgroup);
+	VM_BUG_ON(PageCgroupAcctLRU(pc));
 	/*
-	 * We don't check PCG_USED bit. It's cleared when the "page" is finally
-	 * removed from global LRU.
+	 * putback:				charge:
+	 * SetPageLRU				SetPageCgroupUsed
+	 * smp_mb				smp_mb
+	 * PageCgroupUsed && add to memcg LRU	PageLRU && add to memcg LRU
+	 *
+	 * Ensure that one of the two sides adds the page to the memcg
+	 * LRU during a race.
 	 */
-	mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
-	/* huge page split is done under lru_lock. so, we have no races. */
-	MEM_CGROUP_ZSTAT(mz, lru) -= 1 << compound_order(page);
-	VM_BUG_ON(list_empty(&pc->lru));
-	list_del_init(&pc->lru);
-}
-
-void mem_cgroup_del_lru(struct page *page)
-{
-	mem_cgroup_del_lru_list(page, page_lru(page));
+	smp_mb();
+	/*
+	 * If the page is uncharged, it may be freed soon, but it
+	 * could also be swap cache (readahead, swapoff) that needs to
+	 * be reclaimable in the future.  root_mem_cgroup will babysit
+	 * it for the time being.
+	 */
+	if (PageCgroupUsed(pc)) {
+		/* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
+		smp_rmb();
+		memcg = pc->mem_cgroup;
+		SetPageCgroupAcctLRU(pc);
+	} else
+		memcg = root_mem_cgroup;
+	mz = page_cgroup_zoneinfo(memcg, page);
+	/* compound_order() is stabilized through lru_lock */
+	MEM_CGROUP_ZSTAT(mz, lru) += 1 << compound_order(page);
+	return &mz->lruvec;
 }
 
-/*
- * Writeback is about to end against a page which has been marked for immediate
- * reclaim.  If it still appears to be reclaimable, move it to the tail of the
- * inactive list.
+/**
+ * mem_cgroup_lru_del_list - account for removing an lru page
+ * @page: the page
+ * @lru: target lru
+ *
+ * This function accounts for @page being removed from @lru.
+ *
+ * The callsite is then responsible for physically unlinking
+ * @page->lru.
  */
-void mem_cgroup_rotate_reclaimable_page(struct page *page)
+void mem_cgroup_lru_del_list(struct page *page, enum lru_list lru)
 {
 	struct mem_cgroup_per_zone *mz;
+	struct mem_cgroup *memcg;
 	struct page_cgroup *pc;
-	enum lru_list lru = page_lru(page);
 
 	if (mem_cgroup_disabled())
 		return;
 
 	pc = lookup_page_cgroup(page);
-	/* unused page is not rotated. */
-	if (!PageCgroupUsed(pc))
-		return;
-	/* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
-	smp_rmb();
-	mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
-	list_move_tail(&pc->lru, &mz->lruvec.lists[lru]);
+	/*
+	 * root_mem_cgroup babysits uncharged LRU pages, but
+	 * PageCgroupUsed is cleared when the page is about to get
+	 * freed.  PageCgroupAcctLRU remembers whether the
+	 * LRU-accounting happened against pc->mem_cgroup or
+	 * root_mem_cgroup.
+	 */
+	if (TestClearPageCgroupAcctLRU(pc)) {
+		VM_BUG_ON(!pc->mem_cgroup);
+		memcg = pc->mem_cgroup;
+	} else
+		memcg = root_mem_cgroup;
+	mz = page_cgroup_zoneinfo(memcg, page);
+	/* huge page split is done under lru_lock. so, we have no races. */
+	MEM_CGROUP_ZSTAT(mz, lru) -= 1 << compound_order(page);
 }
 
-void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
+void mem_cgroup_lru_del(struct page *page)
 {
-	struct mem_cgroup_per_zone *mz;
-	struct page_cgroup *pc;
-
-	if (mem_cgroup_disabled())
-		return;
-
-	pc = lookup_page_cgroup(page);
-	/* unused page is not rotated. */
-	if (!PageCgroupUsed(pc))
-		return;
-	/* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
-	smp_rmb();
-	mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
-	list_move(&pc->lru, &mz->lruvec.lists[lru]);
+	mem_cgroup_lru_del_list(page, page_lru(page));
 }
 
-void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
+/**
+ * mem_cgroup_lru_move_lists - account for moving a page between lrus
+ * @zone: zone of the page
+ * @page: the page
+ * @from: current lru
+ * @to: target lru
+ *
+ * This function accounts for @page being moved between the lrus @from
+ * and @to, and returns the lruvec for the given @zone and the memcg
+ * @page is charged to.
+ *
+ * The callsite is then responsible for physically relinking
+ * @page->lru to the returned lruvec->lists[@to].
+ */
+struct lruvec *mem_cgroup_lru_move_lists(struct zone *zone,
+					 struct page *page,
+					 enum lru_list from,
+					 enum lru_list to)
 {
-	struct page_cgroup *pc;
-	struct mem_cgroup_per_zone *mz;
-
-	if (mem_cgroup_disabled())
-		return;
-	pc = lookup_page_cgroup(page);
-	VM_BUG_ON(PageCgroupAcctLRU(pc));
-	/*
-	 * putback:				charge:
-	 * SetPageLRU				SetPageCgroupUsed
-	 * smp_mb				smp_mb
-	 * PageCgroupUsed && add to memcg LRU	PageLRU && add to memcg LRU
-	 *
-	 * Ensure that one of the two sides adds the page to the memcg
-	 * LRU during a race.
-	 */
-	smp_mb();
-	if (!PageCgroupUsed(pc))
-		return;
-	/* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
-	smp_rmb();
-	mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
-	/* huge page split is done under lru_lock. so, we have no races. */
-	MEM_CGROUP_ZSTAT(mz, lru) += 1 << compound_order(page);
-	SetPageCgroupAcctLRU(pc);
-	list_add(&pc->lru, &mz->lruvec.lists[lru]);
+	/* XXX: Optimize this, especially for @from == @to */
+	mem_cgroup_lru_del_list(page, from);
+	return mem_cgroup_lru_add_list(zone, page, to);
 }
 
 /*
@@ -1051,6 +1091,7 @@ void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
  */
 static void mem_cgroup_lru_del_before_commit(struct page *page)
 {
+	enum lru_list lru;
 	unsigned long flags;
 	struct zone *zone = page_zone(page);
 	struct page_cgroup *pc = lookup_page_cgroup(page);
@@ -1067,17 +1108,28 @@ static void mem_cgroup_lru_del_before_commit(struct page *page)
 		return;
 
 	spin_lock_irqsave(&zone->lru_lock, flags);
+	lru = page_lru(page);
 	/*
-	 * Forget old LRU when this page_cgroup is *not* used. This Used bit
-	 * is guarded by lock_page() because the page is SwapCache.
+	 * The uncharged page could still be registered to the LRU of
+	 * the stale pc->mem_cgroup.
+	 *
+	 * As pc->mem_cgroup is about to get overwritten, the old LRU
+	 * accounting needs to be taken care of.  Let root_mem_cgroup
+	 * babysit the page until the new memcg is responsible for it.
+	 *
+	 * The PCG_USED bit is guarded by lock_page() as the page is
+	 * swapcache/pagecache.
 	 */
-	if (!PageCgroupUsed(pc))
-		mem_cgroup_del_lru_list(page, page_lru(page));
+	if (PageLRU(page) && PageCgroupAcctLRU(pc) && !PageCgroupUsed(pc)) {
+		del_page_from_lru_list(zone, page, lru);
+		add_page_to_lru_list(zone, page, lru);
+	}
 	spin_unlock_irqrestore(&zone->lru_lock, flags);
 }
 
 static void mem_cgroup_lru_add_after_commit(struct page *page)
 {
+	enum lru_list lru;
 	unsigned long flags;
 	struct zone *zone = page_zone(page);
 	struct page_cgroup *pc = lookup_page_cgroup(page);
@@ -1095,22 +1147,22 @@ static void mem_cgroup_lru_add_after_commit(struct page *page)
 	if (likely(!PageLRU(page)))
 		return;
 	spin_lock_irqsave(&zone->lru_lock, flags);
-	/* link when the page is linked to LRU but page_cgroup isn't */
-	if (PageLRU(page) && !PageCgroupAcctLRU(pc))
-		mem_cgroup_add_lru_list(page, page_lru(page));
+	lru = page_lru(page);
+	/*
+	 * If the page is not on the LRU, someone will soon put it
+	 * there.  If it is, and also already accounted for on the
+	 * memcg-side, it must be on the right lruvec as setting
+	 * pc->mem_cgroup and PageCgroupUsed is properly ordered.
+	 * Otherwise, root_mem_cgroup has been babysitting the page
+	 * during the charge.  Move it to the new memcg now.
+	 */
+	if (PageLRU(page) && !PageCgroupAcctLRU(pc)) {
+		del_page_from_lru_list(zone, page, lru);
+		add_page_to_lru_list(zone, page, lru);
+	}
 	spin_unlock_irqrestore(&zone->lru_lock, flags);
 }
 
-
-void mem_cgroup_move_lists(struct page *page,
-			   enum lru_list from, enum lru_list to)
-{
-	if (mem_cgroup_disabled())
-		return;
-	mem_cgroup_del_lru_list(page, from);
-	mem_cgroup_add_lru_list(page, to);
-}
-
 /*
  * Checks whether given mem is same or in the root_mem_cgroup's
  * hierarchy subtree
@@ -1216,68 +1268,6 @@ mem_cgroup_get_reclaim_stat_from_page(struct page *page)
 	return &mz->reclaim_stat;
 }
 
-unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
-					struct list_head *dst,
-					unsigned long *scanned, int order,
-					isolate_mode_t mode,
-					struct zone *z,
-					struct mem_cgroup *mem_cont,
-					int active, int file)
-{
-	unsigned long nr_taken = 0;
-	struct page *page;
-	unsigned long scan;
-	LIST_HEAD(pc_list);
-	struct list_head *src;
-	struct page_cgroup *pc, *tmp;
-	int nid = zone_to_nid(z);
-	int zid = zone_idx(z);
-	struct mem_cgroup_per_zone *mz;
-	int lru = LRU_FILE * file + active;
-	int ret;
-
-	BUG_ON(!mem_cont);
-	mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
-	src = &mz->lruvec.lists[lru];
-
-	scan = 0;
-	list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
-		if (scan >= nr_to_scan)
-			break;
-
-		if (unlikely(!PageCgroupUsed(pc)))
-			continue;
-
-		page = lookup_cgroup_page(pc);
-
-		if (unlikely(!PageLRU(page)))
-			continue;
-
-		scan++;
-		ret = __isolate_lru_page(page, mode, file);
-		switch (ret) {
-		case 0:
-			list_move(&page->lru, dst);
-			mem_cgroup_del_lru(page);
-			nr_taken += hpage_nr_pages(page);
-			break;
-		case -EBUSY:
-			/* we don't affect global LRU but rotate in our LRU */
-			mem_cgroup_rotate_lru_list(page, page_lru(page));
-			break;
-		default:
-			break;
-		}
-	}
-
-	*scanned = scan;
-
-	trace_mm_vmscan_memcg_isolate(0, nr_to_scan, scan, nr_taken,
-				      0, 0, 0, mode);
-
-	return nr_taken;
-}
-
 #define mem_cgroup_from_res_counter(counter, member)	\
 	container_of(counter, struct mem_cgroup, member)
 
@@ -3616,11 +3606,11 @@ unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
 static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg,
 				int node, int zid, enum lru_list lru)
 {
-	struct zone *zone;
 	struct mem_cgroup_per_zone *mz;
-	struct page_cgroup *pc, *busy;
 	unsigned long flags, loop;
 	struct list_head *list;
+	struct page *busy;
+	struct zone *zone;
 	int ret = 0;
 
 	zone = &NODE_DATA(node)->node_zones[zid];
@@ -3632,6 +3622,7 @@ static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg,
 	loop += 256;
 	busy = NULL;
 	while (loop--) {
+		struct page_cgroup *pc;
 		struct page *page;
 
 		ret = 0;
@@ -3640,16 +3631,16 @@ static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg,
 			spin_unlock_irqrestore(&zone->lru_lock, flags);
 			break;
 		}
-		pc = list_entry(list->prev, struct page_cgroup, lru);
-		if (busy == pc) {
-			list_move(&pc->lru, list);
+		page = list_entry(list->prev, struct page, lru);
+		if (busy == page) {
+			list_move(&page->lru, list);
 			busy = NULL;
 			spin_unlock_irqrestore(&zone->lru_lock, flags);
 			continue;
 		}
 		spin_unlock_irqrestore(&zone->lru_lock, flags);
 
-		page = lookup_cgroup_page(pc);
+		pc = lookup_page_cgroup(page);
 
 		ret = mem_cgroup_move_parent(page, pc, memcg, GFP_KERNEL);
 		if (ret == -ENOMEM)
@@ -3657,7 +3648,7 @@ static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg,
 
 		if (ret == -EBUSY || ret == -EINVAL) {
 			/* found lock contention or "pc" is obsolete. */
-			busy = pc;
+			busy = page;
 			cond_resched();
 		} else
 			busy = NULL;
diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index 2d123f9..f59405a 100644
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -16,7 +16,6 @@ static void __meminit init_page_cgroup(struct page_cgroup *pc, unsigned long id)
 	pc->flags = 0;
 	set_page_cgroup_array_id(pc, id);
 	pc->mem_cgroup = NULL;
-	INIT_LIST_HEAD(&pc->lru);
 }
 static unsigned long total_usage;
 
diff --git a/mm/swap.c b/mm/swap.c
index 5de4443..5fb3b94 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -232,12 +232,14 @@ static void pagevec_lru_move_fn(struct pagevec *pvec,
 static void pagevec_move_tail_fn(struct page *page, void *arg)
 {
 	int *pgmoved = arg;
-	struct zone *zone = page_zone(page);
 
 	if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
 		enum lru_list lru = page_lru_base_type(page);
-		list_move_tail(&page->lru, &zone->lruvec.lists[lru]);
-		mem_cgroup_rotate_reclaimable_page(page);
+		struct lruvec *lruvec;
+
+		lruvec = mem_cgroup_lru_move_lists(page_zone(page),
+						   page, lru, lru);
+		list_move_tail(&page->lru, &lruvec->lists[lru]);
 		(*pgmoved)++;
 	}
 }
@@ -476,12 +478,13 @@ static void lru_deactivate_fn(struct page *page, void *arg)
 		 */
 		SetPageReclaim(page);
 	} else {
+		struct lruvec *lruvec;
 		/*
 		 * The page's writeback ends up during pagevec
 		 * We moves tha page into tail of inactive.
 		 */
-		list_move_tail(&page->lru, &zone->lruvec.lists[lru]);
-		mem_cgroup_rotate_reclaimable_page(page);
+		lruvec = mem_cgroup_lru_move_lists(zone, page, lru, lru);
+		list_move_tail(&page->lru, &lruvec->lists[lru]);
 		__count_vm_event(PGROTATED);
 	}
 
@@ -671,6 +674,8 @@ void lru_add_page_tail(struct zone* zone,
 	SetPageLRU(page_tail);
 
 	if (page_evictable(page_tail, NULL)) {
+		struct lruvec *lruvec;
+
 		if (PageActive(page)) {
 			SetPageActive(page_tail);
 			active = 1;
@@ -680,11 +685,13 @@ void lru_add_page_tail(struct zone* zone,
 			lru = LRU_INACTIVE_ANON;
 		}
 		update_page_reclaim_stat(zone, page_tail, file, active);
+		lruvec = mem_cgroup_lru_add_list(zone, page_tail, lru);
 		if (likely(PageLRU(page)))
-			__add_page_to_lru_list(zone, page_tail, lru,
-					       page->lru.prev);
+			list_add(&page_tail->lru, page->lru.prev);
 		else
-			add_page_to_lru_list(zone, page_tail, lru);
+			list_add(&page_tail->lru, &lruvec->lists[lru]);
+		__mod_zone_page_state(zone, NR_LRU_BASE + lru,
+				      hpage_nr_pages(page_tail));
 	} else {
 		SetPageUnevictable(page_tail);
 		add_page_to_lru_list(zone, page_tail, LRU_UNEVICTABLE);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 174deff..21ce3cb 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1151,15 +1151,14 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
 
 		switch (__isolate_lru_page(page, mode, file)) {
 		case 0:
+			mem_cgroup_lru_del(page);
 			list_move(&page->lru, dst);
-			mem_cgroup_del_lru(page);
 			nr_taken += hpage_nr_pages(page);
 			break;
 
 		case -EBUSY:
 			/* else it is being freed elsewhere */
 			list_move(&page->lru, src);
-			mem_cgroup_rotate_lru_list(page, page_lru(page));
 			continue;
 
 		default:
@@ -1209,8 +1208,8 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
 				break;
 
 			if (__isolate_lru_page(cursor_page, mode, file) == 0) {
+				mem_cgroup_lru_del(cursor_page);
 				list_move(&cursor_page->lru, dst);
-				mem_cgroup_del_lru(cursor_page);
 				nr_taken += hpage_nr_pages(page);
 				nr_lumpy_taken++;
 				if (PageDirty(cursor_page))
@@ -1251,18 +1250,20 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
 	return nr_taken;
 }
 
-static unsigned long isolate_pages_global(unsigned long nr,
-					struct list_head *dst,
-					unsigned long *scanned, int order,
-					isolate_mode_t mode,
-					struct zone *z,	int active, int file)
+static unsigned long isolate_pages(unsigned long nr, struct mem_cgroup_zone *mz,
+				   struct list_head *dst,
+				   unsigned long *scanned, int order,
+				   isolate_mode_t mode, int active, int file)
 {
+	struct lruvec *lruvec;
 	int lru = LRU_BASE;
+
+	lruvec = mem_cgroup_zone_lruvec(mz->zone, mz->mem_cgroup);
 	if (active)
 		lru += LRU_ACTIVE;
 	if (file)
 		lru += LRU_FILE;
-	return isolate_lru_pages(nr, &z->lruvec.lists[lru], dst,
+	return isolate_lru_pages(nr, &lruvec->lists[lru], dst,
 				 scanned, order, mode, file);
 }
 
@@ -1530,14 +1531,9 @@ shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz,
 
 	spin_lock_irq(&zone->lru_lock);
 
-	if (scanning_global_lru(mz)) {
-		nr_taken = isolate_pages_global(nr_to_scan, &page_list,
-			&nr_scanned, sc->order, reclaim_mode, zone, 0, file);
-	} else {
-		nr_taken = mem_cgroup_isolate_pages(nr_to_scan, &page_list,
-			&nr_scanned, sc->order, reclaim_mode, zone,
-			mz->mem_cgroup, 0, file);
-	}
+	nr_taken = isolate_pages(nr_to_scan, mz, &page_list,
+				 &nr_scanned, sc->order,
+				 reclaim_mode, 0, file);
 	if (global_reclaim(sc)) {
 		zone->pages_scanned += nr_scanned;
 		if (current_is_kswapd())
@@ -1637,13 +1633,15 @@ static void move_active_pages_to_lru(struct zone *zone,
 	pagevec_init(&pvec, 1);
 
 	while (!list_empty(list)) {
+		struct lruvec *lruvec;
+
 		page = lru_to_page(list);
 
 		VM_BUG_ON(PageLRU(page));
 		SetPageLRU(page);
 
-		list_move(&page->lru, &zone->lruvec.lists[lru]);
-		mem_cgroup_add_lru_list(page, lru);
+		lruvec = mem_cgroup_lru_add_list(zone, page, lru);
+		list_move(&page->lru, &lruvec->lists[lru]);
 		pgmoved += hpage_nr_pages(page);
 
 		if (!pagevec_add(&pvec, page) || list_empty(list)) {
@@ -1684,17 +1682,10 @@ static void shrink_active_list(unsigned long nr_pages,
 		reclaim_mode |= ISOLATE_CLEAN;
 
 	spin_lock_irq(&zone->lru_lock);
-	if (scanning_global_lru(mz)) {
-		nr_taken = isolate_pages_global(nr_pages, &l_hold,
-						&pgscanned, sc->order,
-						reclaim_mode, zone,
-						1, file);
-	} else {
-		nr_taken = mem_cgroup_isolate_pages(nr_pages, &l_hold,
-						&pgscanned, sc->order,
-						reclaim_mode, zone,
-						mz->mem_cgroup, 1, file);
-	}
+
+	nr_taken = isolate_pages(nr_pages, mz, &l_hold,
+				 &pgscanned, sc->order,
+				 reclaim_mode, 1, file);
 
 	if (global_reclaim(sc))
 		zone->pages_scanned += pgscanned;
@@ -3451,16 +3442,18 @@ int page_evictable(struct page *page, struct vm_area_struct *vma)
  */
 static void check_move_unevictable_page(struct page *page, struct zone *zone)
 {
-	VM_BUG_ON(PageActive(page));
+	struct lruvec *lruvec;
 
+	VM_BUG_ON(PageActive(page));
 retry:
 	ClearPageUnevictable(page);
 	if (page_evictable(page, NULL)) {
 		enum lru_list l = page_lru_base_type(page);
 
 		__dec_zone_state(zone, NR_UNEVICTABLE);
-		list_move(&page->lru, &zone->lruvec.lists[l]);
-		mem_cgroup_move_lists(page, LRU_UNEVICTABLE, l);
+		lruvec = mem_cgroup_lru_move_lists(zone, page,
+						   LRU_UNEVICTABLE, l);
+		list_move(&page->lru, &lruvec->lists[l]);
 		__inc_zone_state(zone, NR_INACTIVE_ANON + l);
 		__count_vm_event(UNEVICTABLE_PGRESCUED);
 	} else {
@@ -3468,8 +3461,9 @@ retry:
 		 * rotate unevictable list
 		 */
 		SetPageUnevictable(page);
-		list_move(&page->lru, &zone->lruvec.lists[LRU_UNEVICTABLE]);
-		mem_cgroup_rotate_lru_list(page, LRU_UNEVICTABLE);
+		lruvec = mem_cgroup_lru_move_lists(zone, page, LRU_UNEVICTABLE,
+						   LRU_UNEVICTABLE);
+		list_move(&page->lru, &lruvec->lists[LRU_UNEVICTABLE]);
 		if (page_evictable(page, NULL))
 			goto retry;
 	}
-- 
1.7.6.4

--
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^ permalink raw reply related	[flat|nested] 32+ messages in thread
* [patch 10/10] mm: memcg: remove unused node/section info from pc->flags
  2011-11-08 21:23 ` Johannes Weiner
@ 2011-11-08 21:23   ` Johannes Weiner
  -1 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-11-08 21:23 UTC (permalink / raw)
  To: Andrew Morton
  Cc: KAMEZAWA Hiroyuki, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel

To find the page corresponding to a certain page_cgroup, the pc->flags
encoded the node or section ID with the base array to compare the pc
pointer to.

Now that the per-memory cgroup LRU lists link page descriptors
directly, there is no longer any code that knows the struct
page_cgroup of a PFN but not the struct page.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
---
 include/linux/page_cgroup.h |   33 -------------------------
 mm/page_cgroup.c            |   57 +++++-------------------------------------
 2 files changed, 7 insertions(+), 83 deletions(-)

diff --git a/include/linux/page_cgroup.h b/include/linux/page_cgroup.h
index 5bae753..aaa60da 100644
--- a/include/linux/page_cgroup.h
+++ b/include/linux/page_cgroup.h
@@ -121,39 +121,6 @@ static inline void move_unlock_page_cgroup(struct page_cgroup *pc,
 	local_irq_restore(*flags);
 }
 
-#ifdef CONFIG_SPARSEMEM
-#define PCG_ARRAYID_WIDTH	SECTIONS_SHIFT
-#else
-#define PCG_ARRAYID_WIDTH	NODES_SHIFT
-#endif
-
-#if (PCG_ARRAYID_WIDTH > BITS_PER_LONG - NR_PCG_FLAGS)
-#error Not enough space left in pc->flags to store page_cgroup array IDs
-#endif
-
-/* pc->flags: ARRAY-ID | FLAGS */
-
-#define PCG_ARRAYID_MASK	((1UL << PCG_ARRAYID_WIDTH) - 1)
-
-#define PCG_ARRAYID_OFFSET	(BITS_PER_LONG - PCG_ARRAYID_WIDTH)
-/*
- * Zero the shift count for non-existent fields, to prevent compiler
- * warnings and ensure references are optimized away.
- */
-#define PCG_ARRAYID_SHIFT	(PCG_ARRAYID_OFFSET * (PCG_ARRAYID_WIDTH != 0))
-
-static inline void set_page_cgroup_array_id(struct page_cgroup *pc,
-					    unsigned long id)
-{
-	pc->flags &= ~(PCG_ARRAYID_MASK << PCG_ARRAYID_SHIFT);
-	pc->flags |= (id & PCG_ARRAYID_MASK) << PCG_ARRAYID_SHIFT;
-}
-
-static inline unsigned long page_cgroup_array_id(struct page_cgroup *pc)
-{
-	return (pc->flags >> PCG_ARRAYID_SHIFT) & PCG_ARRAYID_MASK;
-}
-
 #else /* CONFIG_CGROUP_MEM_RES_CTLR */
 struct page_cgroup;
 
diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index f59405a..a14655d 100644
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -11,12 +11,6 @@
 #include <linux/swapops.h>
 #include <linux/kmemleak.h>
 
-static void __meminit init_page_cgroup(struct page_cgroup *pc, unsigned long id)
-{
-	pc->flags = 0;
-	set_page_cgroup_array_id(pc, id);
-	pc->mem_cgroup = NULL;
-}
 static unsigned long total_usage;
 
 #if !defined(CONFIG_SPARSEMEM)
@@ -41,24 +35,11 @@ struct page_cgroup *lookup_page_cgroup(struct page *page)
 	return base + offset;
 }
 
-struct page *lookup_cgroup_page(struct page_cgroup *pc)
-{
-	unsigned long pfn;
-	struct page *page;
-	pg_data_t *pgdat;
-
-	pgdat = NODE_DATA(page_cgroup_array_id(pc));
-	pfn = pc - pgdat->node_page_cgroup + pgdat->node_start_pfn;
-	page = pfn_to_page(pfn);
-	VM_BUG_ON(pc != lookup_page_cgroup(page));
-	return page;
-}
-
 static int __init alloc_node_page_cgroup(int nid)
 {
-	struct page_cgroup *base, *pc;
+	struct page_cgroup *base;
 	unsigned long table_size;
-	unsigned long start_pfn, nr_pages, index;
+	unsigned long nr_pages;
 
 	start_pfn = NODE_DATA(nid)->node_start_pfn;
 	nr_pages = NODE_DATA(nid)->node_spanned_pages;
@@ -72,10 +53,6 @@ static int __init alloc_node_page_cgroup(int nid)
 			table_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
 	if (!base)
 		return -ENOMEM;
-	for (index = 0; index < nr_pages; index++) {
-		pc = base + index;
-		init_page_cgroup(pc, nid);
-	}
 	NODE_DATA(nid)->node_page_cgroup = base;
 	total_usage += table_size;
 	return 0;
@@ -116,23 +93,10 @@ struct page_cgroup *lookup_page_cgroup(struct page *page)
 	return section->page_cgroup + pfn;
 }
 
-struct page *lookup_cgroup_page(struct page_cgroup *pc)
-{
-	struct mem_section *section;
-	struct page *page;
-	unsigned long nr;
-
-	nr = page_cgroup_array_id(pc);
-	section = __nr_to_section(nr);
-	page = pfn_to_page(pc - section->page_cgroup);
-	VM_BUG_ON(pc != lookup_page_cgroup(page));
-	return page;
-}
-
 static void *__meminit alloc_page_cgroup(size_t size, int nid)
 {
+	gfp_t flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN;
 	void *addr = NULL;
-	gfp_t flags = GFP_KERNEL | __GFP_NOWARN;
 
 	addr = alloc_pages_exact_nid(nid, size, flags);
 	if (addr) {
@@ -141,9 +105,9 @@ static void *__meminit alloc_page_cgroup(size_t size, int nid)
 	}
 
 	if (node_state(nid, N_HIGH_MEMORY))
-		addr = vmalloc_node(size, nid);
+		addr = vzalloc_node(size, nid);
 	else
-		addr = vmalloc(size);
+		addr = vzalloc(size);
 
 	return addr;
 }
@@ -166,14 +130,11 @@ static void free_page_cgroup(void *addr)
 
 static int __meminit init_section_page_cgroup(unsigned long pfn, int nid)
 {
-	struct page_cgroup *base, *pc;
 	struct mem_section *section;
+	struct page_cgroup *base;
 	unsigned long table_size;
-	unsigned long nr;
-	int index;
 
-	nr = pfn_to_section_nr(pfn);
-	section = __nr_to_section(nr);
+	section = __pfn_to_section(pfn);
 
 	if (section->page_cgroup)
 		return 0;
@@ -193,10 +154,6 @@ static int __meminit init_section_page_cgroup(unsigned long pfn, int nid)
 		return -ENOMEM;
 	}
 
-	for (index = 0; index < PAGES_PER_SECTION; index++) {
-		pc = base + index;
-		init_page_cgroup(pc, nr);
-	}
 	/*
 	 * The passed "pfn" may not be aligned to SECTION.  For the calculation
 	 * we need to apply a mask.
-- 
1.7.6.4


^ permalink raw reply related	[flat|nested] 32+ messages in thread
* [patch 10/10] mm: memcg: remove unused node/section info from pc->flags
@ 2011-11-08 21:23   ` Johannes Weiner
  0 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-11-08 21:23 UTC (permalink / raw)
  To: Andrew Morton
  Cc: KAMEZAWA Hiroyuki, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel

To find the page corresponding to a certain page_cgroup, the pc->flags
encoded the node or section ID with the base array to compare the pc
pointer to.

Now that the per-memory cgroup LRU lists link page descriptors
directly, there is no longer any code that knows the struct
page_cgroup of a PFN but not the struct page.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
---
 include/linux/page_cgroup.h |   33 -------------------------
 mm/page_cgroup.c            |   57 +++++-------------------------------------
 2 files changed, 7 insertions(+), 83 deletions(-)

diff --git a/include/linux/page_cgroup.h b/include/linux/page_cgroup.h
index 5bae753..aaa60da 100644
--- a/include/linux/page_cgroup.h
+++ b/include/linux/page_cgroup.h
@@ -121,39 +121,6 @@ static inline void move_unlock_page_cgroup(struct page_cgroup *pc,
 	local_irq_restore(*flags);
 }
 
-#ifdef CONFIG_SPARSEMEM
-#define PCG_ARRAYID_WIDTH	SECTIONS_SHIFT
-#else
-#define PCG_ARRAYID_WIDTH	NODES_SHIFT
-#endif
-
-#if (PCG_ARRAYID_WIDTH > BITS_PER_LONG - NR_PCG_FLAGS)
-#error Not enough space left in pc->flags to store page_cgroup array IDs
-#endif
-
-/* pc->flags: ARRAY-ID | FLAGS */
-
-#define PCG_ARRAYID_MASK	((1UL << PCG_ARRAYID_WIDTH) - 1)
-
-#define PCG_ARRAYID_OFFSET	(BITS_PER_LONG - PCG_ARRAYID_WIDTH)
-/*
- * Zero the shift count for non-existent fields, to prevent compiler
- * warnings and ensure references are optimized away.
- */
-#define PCG_ARRAYID_SHIFT	(PCG_ARRAYID_OFFSET * (PCG_ARRAYID_WIDTH != 0))
-
-static inline void set_page_cgroup_array_id(struct page_cgroup *pc,
-					    unsigned long id)
-{
-	pc->flags &= ~(PCG_ARRAYID_MASK << PCG_ARRAYID_SHIFT);
-	pc->flags |= (id & PCG_ARRAYID_MASK) << PCG_ARRAYID_SHIFT;
-}
-
-static inline unsigned long page_cgroup_array_id(struct page_cgroup *pc)
-{
-	return (pc->flags >> PCG_ARRAYID_SHIFT) & PCG_ARRAYID_MASK;
-}
-
 #else /* CONFIG_CGROUP_MEM_RES_CTLR */
 struct page_cgroup;
 
diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index f59405a..a14655d 100644
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -11,12 +11,6 @@
 #include <linux/swapops.h>
 #include <linux/kmemleak.h>
 
-static void __meminit init_page_cgroup(struct page_cgroup *pc, unsigned long id)
-{
-	pc->flags = 0;
-	set_page_cgroup_array_id(pc, id);
-	pc->mem_cgroup = NULL;
-}
 static unsigned long total_usage;
 
 #if !defined(CONFIG_SPARSEMEM)
@@ -41,24 +35,11 @@ struct page_cgroup *lookup_page_cgroup(struct page *page)
 	return base + offset;
 }
 
-struct page *lookup_cgroup_page(struct page_cgroup *pc)
-{
-	unsigned long pfn;
-	struct page *page;
-	pg_data_t *pgdat;
-
-	pgdat = NODE_DATA(page_cgroup_array_id(pc));
-	pfn = pc - pgdat->node_page_cgroup + pgdat->node_start_pfn;
-	page = pfn_to_page(pfn);
-	VM_BUG_ON(pc != lookup_page_cgroup(page));
-	return page;
-}
-
 static int __init alloc_node_page_cgroup(int nid)
 {
-	struct page_cgroup *base, *pc;
+	struct page_cgroup *base;
 	unsigned long table_size;
-	unsigned long start_pfn, nr_pages, index;
+	unsigned long nr_pages;
 
 	start_pfn = NODE_DATA(nid)->node_start_pfn;
 	nr_pages = NODE_DATA(nid)->node_spanned_pages;
@@ -72,10 +53,6 @@ static int __init alloc_node_page_cgroup(int nid)
 			table_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
 	if (!base)
 		return -ENOMEM;
-	for (index = 0; index < nr_pages; index++) {
-		pc = base + index;
-		init_page_cgroup(pc, nid);
-	}
 	NODE_DATA(nid)->node_page_cgroup = base;
 	total_usage += table_size;
 	return 0;
@@ -116,23 +93,10 @@ struct page_cgroup *lookup_page_cgroup(struct page *page)
 	return section->page_cgroup + pfn;
 }
 
-struct page *lookup_cgroup_page(struct page_cgroup *pc)
-{
-	struct mem_section *section;
-	struct page *page;
-	unsigned long nr;
-
-	nr = page_cgroup_array_id(pc);
-	section = __nr_to_section(nr);
-	page = pfn_to_page(pc - section->page_cgroup);
-	VM_BUG_ON(pc != lookup_page_cgroup(page));
-	return page;
-}
-
 static void *__meminit alloc_page_cgroup(size_t size, int nid)
 {
+	gfp_t flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN;
 	void *addr = NULL;
-	gfp_t flags = GFP_KERNEL | __GFP_NOWARN;
 
 	addr = alloc_pages_exact_nid(nid, size, flags);
 	if (addr) {
@@ -141,9 +105,9 @@ static void *__meminit alloc_page_cgroup(size_t size, int nid)
 	}
 
 	if (node_state(nid, N_HIGH_MEMORY))
-		addr = vmalloc_node(size, nid);
+		addr = vzalloc_node(size, nid);
 	else
-		addr = vmalloc(size);
+		addr = vzalloc(size);
 
 	return addr;
 }
@@ -166,14 +130,11 @@ static void free_page_cgroup(void *addr)
 
 static int __meminit init_section_page_cgroup(unsigned long pfn, int nid)
 {
-	struct page_cgroup *base, *pc;
 	struct mem_section *section;
+	struct page_cgroup *base;
 	unsigned long table_size;
-	unsigned long nr;
-	int index;
 
-	nr = pfn_to_section_nr(pfn);
-	section = __nr_to_section(nr);
+	section = __pfn_to_section(pfn);
 
 	if (section->page_cgroup)
 		return 0;
@@ -193,10 +154,6 @@ static int __meminit init_section_page_cgroup(unsigned long pfn, int nid)
 		return -ENOMEM;
 	}
 
-	for (index = 0; index < PAGES_PER_SECTION; index++) {
-		pc = base + index;
-		init_page_cgroup(pc, nr);
-	}
 	/*
 	 * The passed "pfn" may not be aligned to SECTION.  For the calculation
 	 * we need to apply a mask.
-- 
1.7.6.4

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply related	[flat|nested] 32+ messages in thread
* Re: [patch 00/10] memcg naturalization -rc5
  2011-11-08 21:23 ` Johannes Weiner
@ 2011-11-09  0:05   ` KAMEZAWA Hiroyuki
  -1 siblings, 0 replies; 32+ messages in thread
From: KAMEZAWA Hiroyuki @ 2011-11-09  0:05 UTC (permalink / raw)
  To: Johannes Weiner
  Cc: Andrew Morton, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel, cgroups

On Tue,  8 Nov 2011 22:23:18 +0100
Johannes Weiner <jweiner@redhat.com> wrote:

> This is version 5 of the memcg naturalization patches.
> 
> They enable traditional page reclaim to find pages from the per-memcg
> LRU lists, thereby getting rid of the double-LRU scheme (per global
> zone in addition to per memcg-zone) and the required extra list head
> per each page in the system.
> 
> The only change from version 4 is using the name `memcg' instead of
> `mem' for memcg pointers in code added in the series.
> 
> This series is based on v3.2-rc1.
> 
> memcg users and distributions are waiting for this because of the
> memory savings.  The changes for regular users that do not create
> memcgs in addition to the root memcg are minimal, and even smaller for
> users that disable the memcg feature at compile time.  Lastly, ongoing
> memcg development, like the breaking up of zone->lru_lock, fixing the
> soft limit implementation/memory guarantees and per-memcg reclaim
> statistics, is already based on this.
> 
> Thanks!

Thank you !.

It seems this series is in -mm now and all memcg patches should be based
on this work.

Note: Everyone, please CC cgroups@vger.kernel.org about cgroup related
changes.

Thanks,
-Kame


^ permalink raw reply	[flat|nested] 32+ messages in thread
* Re: [patch 00/10] memcg naturalization -rc5
@ 2011-11-09  0:05   ` KAMEZAWA Hiroyuki
  0 siblings, 0 replies; 32+ messages in thread
From: KAMEZAWA Hiroyuki @ 2011-11-09  0:05 UTC (permalink / raw)
  To: Johannes Weiner
  Cc: Andrew Morton, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel, cgroups

On Tue,  8 Nov 2011 22:23:18 +0100
Johannes Weiner <jweiner@redhat.com> wrote:

> This is version 5 of the memcg naturalization patches.
> 
> They enable traditional page reclaim to find pages from the per-memcg
> LRU lists, thereby getting rid of the double-LRU scheme (per global
> zone in addition to per memcg-zone) and the required extra list head
> per each page in the system.
> 
> The only change from version 4 is using the name `memcg' instead of
> `mem' for memcg pointers in code added in the series.
> 
> This series is based on v3.2-rc1.
> 
> memcg users and distributions are waiting for this because of the
> memory savings.  The changes for regular users that do not create
> memcgs in addition to the root memcg are minimal, and even smaller for
> users that disable the memcg feature at compile time.  Lastly, ongoing
> memcg development, like the breaking up of zone->lru_lock, fixing the
> soft limit implementation/memory guarantees and per-memcg reclaim
> statistics, is already based on this.
> 
> Thanks!

Thank you !.

It seems this series is in -mm now and all memcg patches should be based
on this work.

Note: Everyone, please CC cgroups@vger.kernel.org about cgroup related
changes.

Thanks,
-Kame

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^ permalink raw reply	[flat|nested] 32+ messages in thread
* [PATCH mm] mm: memcg: remove unused node/section info from pc->flags fix
  2011-11-08 21:23   ` Johannes Weiner
@ 2011-11-09  5:18     ` Hugh Dickins
  -1 siblings, 0 replies; 32+ messages in thread
From: Hugh Dickins @ 2011-11-09  5:18 UTC (permalink / raw)
  To: Andrew Morton
  Cc: Johannes Weiner, KAMEZAWA Hiroyuki, Michal Hocko,
	Kirill A. Shutemov, Daisuke Nishimura, Balbir Singh, Ying Han,
	Greg Thelen, Michel Lespinasse, Rik van Riel, Minchan Kim,
	Christoph Hellwig, Stephen Rothwell, linux-mm, linux-kernel

Fix non-CONFIG_SPARSEMEM build, which failed with
mm/page_cgroup.c: In function `alloc_node_page_cgroup':
mm/page_cgroup.c:44: error: `start_pfn' undeclared (first use in this function)

Signed-off-by: Hugh Dickins <hughd@google.com>
---
For folding into mm-memcg-remove-unused-node-section-info-from-pc-flags.patch

 mm/page_cgroup.c |    2 --
 1 file changed, 2 deletions(-)

Hannes: heartfelt thanks to you for this great work - Hugh

--- 3.2-rc1-jw/mm/page_cgroup.c	2011-11-08 20:25:24.678395000 -0800
+++ linux/mm/page_cgroup.c	2011-11-08 20:42:05.687358464 -0800
@@ -41,9 +41,7 @@ static int __init alloc_node_page_cgroup
 	unsigned long table_size;
 	unsigned long nr_pages;
 
-	start_pfn = NODE_DATA(nid)->node_start_pfn;
 	nr_pages = NODE_DATA(nid)->node_spanned_pages;
-
 	if (!nr_pages)
 		return 0;
 

^ permalink raw reply	[flat|nested] 32+ messages in thread
* [PATCH mm] mm: memcg: remove unused node/section info from pc->flags fix
@ 2011-11-09  5:18     ` Hugh Dickins
  0 siblings, 0 replies; 32+ messages in thread
From: Hugh Dickins @ 2011-11-09  5:18 UTC (permalink / raw)
  To: Andrew Morton
  Cc: Johannes Weiner, KAMEZAWA Hiroyuki, Michal Hocko,
	Kirill A. Shutemov, Daisuke Nishimura, Balbir Singh, Ying Han,
	Greg Thelen, Michel Lespinasse, Rik van Riel, Minchan Kim,
	Christoph Hellwig, Stephen Rothwell, linux-mm, linux-kernel

Fix non-CONFIG_SPARSEMEM build, which failed with
mm/page_cgroup.c: In function `alloc_node_page_cgroup':
mm/page_cgroup.c:44: error: `start_pfn' undeclared (first use in this function)

Signed-off-by: Hugh Dickins <hughd@google.com>
---
For folding into mm-memcg-remove-unused-node-section-info-from-pc-flags.patch

 mm/page_cgroup.c |    2 --
 1 file changed, 2 deletions(-)

Hannes: heartfelt thanks to you for this great work - Hugh

--- 3.2-rc1-jw/mm/page_cgroup.c	2011-11-08 20:25:24.678395000 -0800
+++ linux/mm/page_cgroup.c	2011-11-08 20:42:05.687358464 -0800
@@ -41,9 +41,7 @@ static int __init alloc_node_page_cgroup
 	unsigned long table_size;
 	unsigned long nr_pages;
 
-	start_pfn = NODE_DATA(nid)->node_start_pfn;
 	nr_pages = NODE_DATA(nid)->node_spanned_pages;
-
 	if (!nr_pages)
 		return 0;
 

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^ permalink raw reply	[flat|nested] 32+ messages in thread
* Re: [PATCH mm] mm: memcg: remove unused node/section info from pc->flags fix
  2011-11-09  5:18     ` Hugh Dickins
@ 2011-11-09  5:27       ` KAMEZAWA Hiroyuki
  -1 siblings, 0 replies; 32+ messages in thread
From: KAMEZAWA Hiroyuki @ 2011-11-09  5:27 UTC (permalink / raw)
  To: Hugh Dickins
  Cc: Andrew Morton, Johannes Weiner, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Stephen Rothwell, linux-mm, linux-kernel

On Tue, 8 Nov 2011 21:18:10 -0800 (PST)
Hugh Dickins <hughd@google.com> wrote:

> Fix non-CONFIG_SPARSEMEM build, which failed with
> mm/page_cgroup.c: In function `alloc_node_page_cgroup':
> mm/page_cgroup.c:44: error: `start_pfn' undeclared (first use in this function)
> 
> Signed-off-by: Hugh Dickins <hughd@google.com>

Thank you.
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>


^ permalink raw reply	[flat|nested] 32+ messages in thread
* Re: [PATCH mm] mm: memcg: remove unused node/section info from pc->flags fix
@ 2011-11-09  5:27       ` KAMEZAWA Hiroyuki
  0 siblings, 0 replies; 32+ messages in thread
From: KAMEZAWA Hiroyuki @ 2011-11-09  5:27 UTC (permalink / raw)
  To: Hugh Dickins
  Cc: Andrew Morton, Johannes Weiner, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Stephen Rothwell, linux-mm, linux-kernel

On Tue, 8 Nov 2011 21:18:10 -0800 (PST)
Hugh Dickins <hughd@google.com> wrote:

> Fix non-CONFIG_SPARSEMEM build, which failed with
> mm/page_cgroup.c: In function `alloc_node_page_cgroup':
> mm/page_cgroup.c:44: error: `start_pfn' undeclared (first use in this function)
> 
> Signed-off-by: Hugh Dickins <hughd@google.com>

Thank you.
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>

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^ permalink raw reply	[flat|nested] 32+ messages in thread
* Re: [PATCH mm] mm: memcg: remove unused node/section info from pc->flags fix
  2011-11-09  5:18     ` Hugh Dickins
@ 2011-11-09 13:14       ` Johannes Weiner
  -1 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-11-09 13:14 UTC (permalink / raw)
  To: Hugh Dickins
  Cc: Andrew Morton, KAMEZAWA Hiroyuki, Michal Hocko,
	Kirill A. Shutemov, Daisuke Nishimura, Balbir Singh, Ying Han,
	Greg Thelen, Michel Lespinasse, Rik van Riel, Minchan Kim,
	Christoph Hellwig, Stephen Rothwell, linux-mm, linux-kernel

On Tue, Nov 08, 2011 at 09:18:10PM -0800, Hugh Dickins wrote:
> Fix non-CONFIG_SPARSEMEM build, which failed with
> mm/page_cgroup.c: In function `alloc_node_page_cgroup':
> mm/page_cgroup.c:44: error: `start_pfn' undeclared (first use in this function)
> 
> Signed-off-by: Hugh Dickins <hughd@google.com>
> ---
> For folding into mm-memcg-remove-unused-node-section-info-from-pc-flags.patch
> 
>  mm/page_cgroup.c |    2 --
>  1 file changed, 2 deletions(-)
> 
> Hannes: heartfelt thanks to you for this great work - Hugh

Thanks, I appreciate it.  Sorry for the trouble, the patch is
obviously correct.

^ permalink raw reply	[flat|nested] 32+ messages in thread
* Re: [PATCH mm] mm: memcg: remove unused node/section info from pc->flags fix
@ 2011-11-09 13:14       ` Johannes Weiner
  0 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-11-09 13:14 UTC (permalink / raw)
  To: Hugh Dickins
  Cc: Andrew Morton, KAMEZAWA Hiroyuki, Michal Hocko,
	Kirill A. Shutemov, Daisuke Nishimura, Balbir Singh, Ying Han,
	Greg Thelen, Michel Lespinasse, Rik van Riel, Minchan Kim,
	Christoph Hellwig, Stephen Rothwell, linux-mm, linux-kernel

On Tue, Nov 08, 2011 at 09:18:10PM -0800, Hugh Dickins wrote:
> Fix non-CONFIG_SPARSEMEM build, which failed with
> mm/page_cgroup.c: In function `alloc_node_page_cgroup':
> mm/page_cgroup.c:44: error: `start_pfn' undeclared (first use in this function)
> 
> Signed-off-by: Hugh Dickins <hughd@google.com>
> ---
> For folding into mm-memcg-remove-unused-node-section-info-from-pc-flags.patch
> 
>  mm/page_cgroup.c |    2 --
>  1 file changed, 2 deletions(-)
> 
> Hannes: heartfelt thanks to you for this great work - Hugh

Thanks, I appreciate it.  Sorry for the trouble, the patch is
obviously correct.

--
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^ permalink raw reply	[flat|nested] 32+ messages in thread
* [patch 03/10] mm: vmscan: distinguish between memcg triggering reclaim and memcg being scanned
  2011-09-29 21:00 [patch 00/10] memcg naturalization -rc4 Johannes Weiner
@ 2011-09-29 21:00   ` Johannes Weiner
  0 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-09-29 21:00 UTC (permalink / raw)
  To: Andrew Morton
  Cc: KAMEZAWA Hiroyuki, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel

Memory cgroup hierarchies are currently handled completely outside of
the traditional reclaim code, which is invoked with a single memory
cgroup as an argument for the whole call stack.

Subsequent patches will switch this code to do hierarchical reclaim,
so there needs to be a distinction between a) the memory cgroup that
is triggering reclaim due to hitting its limit and b) the memory
cgroup that is being scanned as a child of a).

This patch introduces a struct mem_cgroup_zone that contains the
combination of the memory cgroup and the zone being scanned, which is
then passed down the stack instead of the zone argument.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
---
 mm/vmscan.c |  249 +++++++++++++++++++++++++++++++++--------------------------
 1 files changed, 141 insertions(+), 108 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 4bb7f78..88ccdd8 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -103,8 +103,11 @@ struct scan_control {
 	 */
 	reclaim_mode_t reclaim_mode;
 
-	/* Which cgroup do we reclaim from */
-	struct mem_cgroup *mem_cgroup;
+	/*
+	 * The memory cgroup that hit its limit and as a result is the
+	 * primary target of this reclaim invocation.
+	 */
+	struct mem_cgroup *target_mem_cgroup;
 
 	/*
 	 * Nodemask of nodes allowed by the caller. If NULL, all nodes
@@ -113,6 +116,11 @@ struct scan_control {
 	nodemask_t	*nodemask;
 };
 
+struct mem_cgroup_zone {
+	struct mem_cgroup *mem_cgroup;
+	struct zone *zone;
+};
+
 #define lru_to_page(_head) (list_entry((_head)->prev, struct page, lru))
 
 #ifdef ARCH_HAS_PREFETCH
@@ -155,12 +163,12 @@ static DECLARE_RWSEM(shrinker_rwsem);
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR
 static bool global_reclaim(struct scan_control *sc)
 {
-	return !sc->mem_cgroup;
+	return !sc->target_mem_cgroup;
 }
 
-static bool scanning_global_lru(struct scan_control *sc)
+static bool scanning_global_lru(struct mem_cgroup_zone *mz)
 {
-	return !sc->mem_cgroup;
+	return !mz->mem_cgroup;
 }
 #else
 static bool global_reclaim(struct scan_control *sc)
@@ -168,29 +176,30 @@ static bool global_reclaim(struct scan_control *sc)
 	return true;
 }
 
-static bool scanning_global_lru(struct scan_control *sc)
+static bool scanning_global_lru(struct mem_cgroup_zone *mz)
 {
 	return true;
 }
 #endif
 
-static struct zone_reclaim_stat *get_reclaim_stat(struct zone *zone,
-						  struct scan_control *sc)
+static struct zone_reclaim_stat *get_reclaim_stat(struct mem_cgroup_zone *mz)
 {
-	if (!scanning_global_lru(sc))
-		return mem_cgroup_get_reclaim_stat(sc->mem_cgroup, zone);
+	if (!scanning_global_lru(mz))
+		return mem_cgroup_get_reclaim_stat(mz->mem_cgroup, mz->zone);
 
-	return &zone->reclaim_stat;
+	return &mz->zone->reclaim_stat;
 }
 
-static unsigned long zone_nr_lru_pages(struct zone *zone,
-				struct scan_control *sc, enum lru_list lru)
+static unsigned long zone_nr_lru_pages(struct mem_cgroup_zone *mz,
+				       enum lru_list lru)
 {
-	if (!scanning_global_lru(sc))
-		return mem_cgroup_zone_nr_lru_pages(sc->mem_cgroup,
-				zone_to_nid(zone), zone_idx(zone), BIT(lru));
+	if (!scanning_global_lru(mz))
+		return mem_cgroup_zone_nr_lru_pages(mz->mem_cgroup,
+						    zone_to_nid(mz->zone),
+						    zone_idx(mz->zone),
+						    BIT(lru));
 
-	return zone_page_state(zone, NR_LRU_BASE + lru);
+	return zone_page_state(mz->zone, NR_LRU_BASE + lru);
 }
 
 
@@ -692,12 +701,13 @@ enum page_references {
 };
 
 static enum page_references page_check_references(struct page *page,
+						  struct mem_cgroup_zone *mz,
 						  struct scan_control *sc)
 {
 	int referenced_ptes, referenced_page;
 	unsigned long vm_flags;
 
-	referenced_ptes = page_referenced(page, 1, sc->mem_cgroup, &vm_flags);
+	referenced_ptes = page_referenced(page, 1, mz->mem_cgroup, &vm_flags);
 	referenced_page = TestClearPageReferenced(page);
 
 	/* Lumpy reclaim - ignore references */
@@ -771,7 +781,7 @@ static noinline_for_stack void free_page_list(struct list_head *free_pages)
  * shrink_page_list() returns the number of reclaimed pages
  */
 static unsigned long shrink_page_list(struct list_head *page_list,
-				      struct zone *zone,
+				      struct mem_cgroup_zone *mz,
 				      struct scan_control *sc,
 				      int priority,
 				      unsigned long *ret_nr_dirty,
@@ -802,7 +812,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 			goto keep;
 
 		VM_BUG_ON(PageActive(page));
-		VM_BUG_ON(page_zone(page) != zone);
+		VM_BUG_ON(page_zone(page) != mz->zone);
 
 		sc->nr_scanned++;
 
@@ -836,7 +846,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 			}
 		}
 
-		references = page_check_references(page, sc);
+		references = page_check_references(page, mz, sc);
 		switch (references) {
 		case PAGEREF_ACTIVATE:
 			goto activate_locked;
@@ -1028,7 +1038,7 @@ keep_lumpy:
 	 * will encounter the same problem
 	 */
 	if (nr_dirty && nr_dirty == nr_congested && global_reclaim(sc))
-		zone_set_flag(zone, ZONE_CONGESTED);
+		zone_set_flag(mz->zone, ZONE_CONGESTED);
 
 	free_page_list(&free_pages);
 
@@ -1364,13 +1374,14 @@ static int too_many_isolated(struct zone *zone, int file,
  * TODO: Try merging with migrations version of putback_lru_pages
  */
 static noinline_for_stack void
-putback_lru_pages(struct zone *zone, struct scan_control *sc,
-				unsigned long nr_anon, unsigned long nr_file,
-				struct list_head *page_list)
+putback_lru_pages(struct mem_cgroup_zone *mz, struct scan_control *sc,
+		  unsigned long nr_anon, unsigned long nr_file,
+		  struct list_head *page_list)
 {
 	struct page *page;
 	struct pagevec pvec;
-	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
+	struct zone *zone = mz->zone;
+	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(mz);
 
 	pagevec_init(&pvec, 1);
 
@@ -1410,15 +1421,17 @@ putback_lru_pages(struct zone *zone, struct scan_control *sc,
 	pagevec_release(&pvec);
 }
 
-static noinline_for_stack void update_isolated_counts(struct zone *zone,
-					struct scan_control *sc,
-					unsigned long *nr_anon,
-					unsigned long *nr_file,
-					struct list_head *isolated_list)
+static noinline_for_stack void
+update_isolated_counts(struct mem_cgroup_zone *mz,
+		       struct scan_control *sc,
+		       unsigned long *nr_anon,
+		       unsigned long *nr_file,
+		       struct list_head *isolated_list)
 {
 	unsigned long nr_active;
+	struct zone *zone = mz->zone;
 	unsigned int count[NR_LRU_LISTS] = { 0, };
-	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
+	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(mz);
 
 	nr_active = clear_active_flags(isolated_list, count);
 	__count_vm_events(PGDEACTIVATE, nr_active);
@@ -1487,8 +1500,8 @@ static inline bool should_reclaim_stall(unsigned long nr_taken,
  * of reclaimed pages
  */
 static noinline_for_stack unsigned long
-shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
-			struct scan_control *sc, int priority, int file)
+shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz,
+		     struct scan_control *sc, int priority, int file)
 {
 	LIST_HEAD(page_list);
 	unsigned long nr_scanned;
@@ -1499,6 +1512,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
 	unsigned long nr_dirty = 0;
 	unsigned long nr_writeback = 0;
 	isolate_mode_t reclaim_mode = ISOLATE_INACTIVE;
+	struct zone *zone = mz->zone;
 
 	while (unlikely(too_many_isolated(zone, file, sc))) {
 		congestion_wait(BLK_RW_ASYNC, HZ/10);
@@ -1521,13 +1535,13 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
 
 	spin_lock_irq(&zone->lru_lock);
 
-	if (scanning_global_lru(sc)) {
+	if (scanning_global_lru(mz)) {
 		nr_taken = isolate_pages_global(nr_to_scan, &page_list,
 			&nr_scanned, sc->order, reclaim_mode, zone, 0, file);
 	} else {
 		nr_taken = mem_cgroup_isolate_pages(nr_to_scan, &page_list,
 			&nr_scanned, sc->order, reclaim_mode, zone,
-			sc->mem_cgroup, 0, file);
+			mz->mem_cgroup, 0, file);
 	}
 	if (global_reclaim(sc)) {
 		zone->pages_scanned += nr_scanned;
@@ -1544,17 +1558,17 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
 		return 0;
 	}
 
-	update_isolated_counts(zone, sc, &nr_anon, &nr_file, &page_list);
+	update_isolated_counts(mz, sc, &nr_anon, &nr_file, &page_list);
 
 	spin_unlock_irq(&zone->lru_lock);
 
-	nr_reclaimed = shrink_page_list(&page_list, zone, sc, priority,
+	nr_reclaimed = shrink_page_list(&page_list, mz, sc, priority,
 						&nr_dirty, &nr_writeback);
 
 	/* Check if we should syncronously wait for writeback */
 	if (should_reclaim_stall(nr_taken, nr_reclaimed, priority, sc)) {
 		set_reclaim_mode(priority, sc, true);
-		nr_reclaimed += shrink_page_list(&page_list, zone, sc,
+		nr_reclaimed += shrink_page_list(&page_list, mz, sc,
 					priority, &nr_dirty, &nr_writeback);
 	}
 
@@ -1563,7 +1577,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
 		__count_vm_events(KSWAPD_STEAL, nr_reclaimed);
 	__count_zone_vm_events(PGSTEAL, zone, nr_reclaimed);
 
-	putback_lru_pages(zone, sc, nr_anon, nr_file, &page_list);
+	putback_lru_pages(mz, sc, nr_anon, nr_file, &page_list);
 
 	/*
 	 * If we have encountered a high number of dirty pages under writeback
@@ -1634,8 +1648,10 @@ static void move_active_pages_to_lru(struct zone *zone,
 		__count_vm_events(PGDEACTIVATE, pgmoved);
 }
 
-static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
-			struct scan_control *sc, int priority, int file)
+static void shrink_active_list(unsigned long nr_pages,
+			       struct mem_cgroup_zone *mz,
+			       struct scan_control *sc,
+			       int priority, int file)
 {
 	unsigned long nr_taken;
 	unsigned long pgscanned;
@@ -1644,9 +1660,10 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 	LIST_HEAD(l_active);
 	LIST_HEAD(l_inactive);
 	struct page *page;
-	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
+	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(mz);
 	unsigned long nr_rotated = 0;
 	isolate_mode_t reclaim_mode = ISOLATE_ACTIVE;
+	struct zone *zone = mz->zone;
 
 	lru_add_drain();
 
@@ -1656,7 +1673,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 		reclaim_mode |= ISOLATE_CLEAN;
 
 	spin_lock_irq(&zone->lru_lock);
-	if (scanning_global_lru(sc)) {
+	if (scanning_global_lru(mz)) {
 		nr_taken = isolate_pages_global(nr_pages, &l_hold,
 						&pgscanned, sc->order,
 						reclaim_mode, zone,
@@ -1665,7 +1682,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 		nr_taken = mem_cgroup_isolate_pages(nr_pages, &l_hold,
 						&pgscanned, sc->order,
 						reclaim_mode, zone,
-						sc->mem_cgroup, 1, file);
+						mz->mem_cgroup, 1, file);
 	}
 
 	if (global_reclaim(sc))
@@ -1691,7 +1708,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 			continue;
 		}
 
-		if (page_referenced(page, 0, sc->mem_cgroup, &vm_flags)) {
+		if (page_referenced(page, 0, mz->mem_cgroup, &vm_flags)) {
 			nr_rotated += hpage_nr_pages(page);
 			/*
 			 * Identify referenced, file-backed active pages and
@@ -1754,10 +1771,8 @@ static int inactive_anon_is_low_global(struct zone *zone)
  * Returns true if the zone does not have enough inactive anon pages,
  * meaning some active anon pages need to be deactivated.
  */
-static int inactive_anon_is_low(struct zone *zone, struct scan_control *sc)
+static int inactive_anon_is_low(struct mem_cgroup_zone *mz)
 {
-	int low;
-
 	/*
 	 * If we don't have swap space, anonymous page deactivation
 	 * is pointless.
@@ -1765,15 +1780,14 @@ static int inactive_anon_is_low(struct zone *zone, struct scan_control *sc)
 	if (!total_swap_pages)
 		return 0;
 
-	if (scanning_global_lru(sc))
-		low = inactive_anon_is_low_global(zone);
-	else
-		low = mem_cgroup_inactive_anon_is_low(sc->mem_cgroup, zone);
-	return low;
+	if (!scanning_global_lru(mz))
+		return mem_cgroup_inactive_anon_is_low(mz->mem_cgroup,
+						       mz->zone);
+
+	return inactive_anon_is_low_global(mz->zone);
 }
 #else
-static inline int inactive_anon_is_low(struct zone *zone,
-					struct scan_control *sc)
+static inline int inactive_anon_is_low(struct mem_cgroup_zone *mz)
 {
 	return 0;
 }
@@ -1791,8 +1805,7 @@ static int inactive_file_is_low_global(struct zone *zone)
 
 /**
  * inactive_file_is_low - check if file pages need to be deactivated
- * @zone: zone to check
- * @sc:   scan control of this context
+ * @mz: memory cgroup and zone to check
  *
  * When the system is doing streaming IO, memory pressure here
  * ensures that active file pages get deactivated, until more
@@ -1804,45 +1817,44 @@ static int inactive_file_is_low_global(struct zone *zone)
  * This uses a different ratio than the anonymous pages, because
  * the page cache uses a use-once replacement algorithm.
  */
-static int inactive_file_is_low(struct zone *zone, struct scan_control *sc)
+static int inactive_file_is_low(struct mem_cgroup_zone *mz)
 {
-	int low;
+	if (!scanning_global_lru(mz))
+		return mem_cgroup_inactive_file_is_low(mz->mem_cgroup,
+						       mz->zone);
 
-	if (scanning_global_lru(sc))
-		low = inactive_file_is_low_global(zone);
-	else
-		low = mem_cgroup_inactive_file_is_low(sc->mem_cgroup, zone);
-	return low;
+	return inactive_file_is_low_global(mz->zone);
 }
 
-static int inactive_list_is_low(struct zone *zone, struct scan_control *sc,
-				int file)
+static int inactive_list_is_low(struct mem_cgroup_zone *mz, int file)
 {
 	if (file)
-		return inactive_file_is_low(zone, sc);
+		return inactive_file_is_low(mz);
 	else
-		return inactive_anon_is_low(zone, sc);
+		return inactive_anon_is_low(mz);
 }
 
 static unsigned long shrink_list(enum lru_list lru, unsigned long nr_to_scan,
-	struct zone *zone, struct scan_control *sc, int priority)
+				 struct mem_cgroup_zone *mz,
+				 struct scan_control *sc, int priority)
 {
 	int file = is_file_lru(lru);
 
 	if (is_active_lru(lru)) {
-		if (inactive_list_is_low(zone, sc, file))
-		    shrink_active_list(nr_to_scan, zone, sc, priority, file);
+		if (inactive_list_is_low(mz, file))
+		    shrink_active_list(nr_to_scan, mz, sc, priority, file);
 		return 0;
 	}
 
-	return shrink_inactive_list(nr_to_scan, zone, sc, priority, file);
+	return shrink_inactive_list(nr_to_scan, mz, sc, priority, file);
 }
 
-static int vmscan_swappiness(struct scan_control *sc)
+static int vmscan_swappiness(struct mem_cgroup_zone *mz,
+			     struct scan_control *sc)
 {
 	if (global_reclaim(sc))
 		return vm_swappiness;
-	return mem_cgroup_swappiness(sc->mem_cgroup);
+	return mem_cgroup_swappiness(mz->mem_cgroup);
 }
 
 /*
@@ -1853,13 +1865,13 @@ static int vmscan_swappiness(struct scan_control *sc)
  *
  * nr[0] = anon pages to scan; nr[1] = file pages to scan
  */
-static void get_scan_count(struct zone *zone, struct scan_control *sc,
-					unsigned long *nr, int priority)
+static void get_scan_count(struct mem_cgroup_zone *mz, struct scan_control *sc,
+			   unsigned long *nr, int priority)
 {
 	unsigned long anon, file, free;
 	unsigned long anon_prio, file_prio;
 	unsigned long ap, fp;
-	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
+	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(mz);
 	u64 fraction[2], denominator;
 	enum lru_list l;
 	int noswap = 0;
@@ -1889,16 +1901,16 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
 		goto out;
 	}
 
-	anon  = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_ANON) +
-		zone_nr_lru_pages(zone, sc, LRU_INACTIVE_ANON);
-	file  = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_FILE) +
-		zone_nr_lru_pages(zone, sc, LRU_INACTIVE_FILE);
+	anon  = zone_nr_lru_pages(mz, LRU_ACTIVE_ANON) +
+		zone_nr_lru_pages(mz, LRU_INACTIVE_ANON);
+	file  = zone_nr_lru_pages(mz, LRU_ACTIVE_FILE) +
+		zone_nr_lru_pages(mz, LRU_INACTIVE_FILE);
 
 	if (global_reclaim(sc)) {
-		free  = zone_page_state(zone, NR_FREE_PAGES);
+		free  = zone_page_state(mz->zone, NR_FREE_PAGES);
 		/* If we have very few page cache pages,
 		   force-scan anon pages. */
-		if (unlikely(file + free <= high_wmark_pages(zone))) {
+		if (unlikely(file + free <= high_wmark_pages(mz->zone))) {
 			fraction[0] = 1;
 			fraction[1] = 0;
 			denominator = 1;
@@ -1910,8 +1922,8 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
 	 * With swappiness at 100, anonymous and file have the same priority.
 	 * This scanning priority is essentially the inverse of IO cost.
 	 */
-	anon_prio = vmscan_swappiness(sc);
-	file_prio = 200 - vmscan_swappiness(sc);
+	anon_prio = vmscan_swappiness(mz, sc);
+	file_prio = 200 - vmscan_swappiness(mz, sc);
 
 	/*
 	 * OK, so we have swap space and a fair amount of page cache
@@ -1924,7 +1936,7 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
 	 *
 	 * anon in [0], file in [1]
 	 */
-	spin_lock_irq(&zone->lru_lock);
+	spin_lock_irq(&mz->zone->lru_lock);
 	if (unlikely(reclaim_stat->recent_scanned[0] > anon / 4)) {
 		reclaim_stat->recent_scanned[0] /= 2;
 		reclaim_stat->recent_rotated[0] /= 2;
@@ -1945,7 +1957,7 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
 
 	fp = (file_prio + 1) * (reclaim_stat->recent_scanned[1] + 1);
 	fp /= reclaim_stat->recent_rotated[1] + 1;
-	spin_unlock_irq(&zone->lru_lock);
+	spin_unlock_irq(&mz->zone->lru_lock);
 
 	fraction[0] = ap;
 	fraction[1] = fp;
@@ -1955,7 +1967,7 @@ out:
 		int file = is_file_lru(l);
 		unsigned long scan;
 
-		scan = zone_nr_lru_pages(zone, sc, l);
+		scan = zone_nr_lru_pages(mz, l);
 		if (priority || noswap) {
 			scan >>= priority;
 			if (!scan && force_scan)
@@ -1973,7 +1985,7 @@ out:
  * back to the allocator and call try_to_compact_zone(), we ensure that
  * there are enough free pages for it to be likely successful
  */
-static inline bool should_continue_reclaim(struct zone *zone,
+static inline bool should_continue_reclaim(struct mem_cgroup_zone *mz,
 					unsigned long nr_reclaimed,
 					unsigned long nr_scanned,
 					struct scan_control *sc)
@@ -2013,14 +2025,14 @@ static inline bool should_continue_reclaim(struct zone *zone,
 	 * inactive lists are large enough, continue reclaiming
 	 */
 	pages_for_compaction = (2UL << sc->order);
-	inactive_lru_pages = zone_nr_lru_pages(zone, sc, LRU_INACTIVE_ANON) +
-				zone_nr_lru_pages(zone, sc, LRU_INACTIVE_FILE);
+	inactive_lru_pages = zone_nr_lru_pages(mz, LRU_INACTIVE_ANON) +
+				zone_nr_lru_pages(mz, LRU_INACTIVE_FILE);
 	if (sc->nr_reclaimed < pages_for_compaction &&
 			inactive_lru_pages > pages_for_compaction)
 		return true;
 
 	/* If compaction would go ahead or the allocation would succeed, stop */
-	switch (compaction_suitable(zone, sc->order)) {
+	switch (compaction_suitable(mz->zone, sc->order)) {
 	case COMPACT_PARTIAL:
 	case COMPACT_CONTINUE:
 		return false;
@@ -2032,8 +2044,8 @@ static inline bool should_continue_reclaim(struct zone *zone,
 /*
  * This is a basic per-zone page freer.  Used by both kswapd and direct reclaim.
  */
-static void shrink_zone(int priority, struct zone *zone,
-				struct scan_control *sc)
+static void shrink_mem_cgroup_zone(int priority, struct mem_cgroup_zone *mz,
+				   struct scan_control *sc)
 {
 	unsigned long nr[NR_LRU_LISTS];
 	unsigned long nr_to_scan;
@@ -2045,7 +2057,7 @@ static void shrink_zone(int priority, struct zone *zone,
 restart:
 	nr_reclaimed = 0;
 	nr_scanned = sc->nr_scanned;
-	get_scan_count(zone, sc, nr, priority);
+	get_scan_count(mz, sc, nr, priority);
 
 	blk_start_plug(&plug);
 	while (nr[LRU_INACTIVE_ANON] || nr[LRU_ACTIVE_FILE] ||
@@ -2057,7 +2069,7 @@ restart:
 				nr[l] -= nr_to_scan;
 
 				nr_reclaimed += shrink_list(l, nr_to_scan,
-							    zone, sc, priority);
+							    mz, sc, priority);
 			}
 		}
 		/*
@@ -2078,17 +2090,28 @@ restart:
 	 * Even if we did not try to evict anon pages at all, we want to
 	 * rebalance the anon lru active/inactive ratio.
 	 */
-	if (inactive_anon_is_low(zone, sc))
-		shrink_active_list(SWAP_CLUSTER_MAX, zone, sc, priority, 0);
+	if (inactive_anon_is_low(mz))
+		shrink_active_list(SWAP_CLUSTER_MAX, mz, sc, priority, 0);
 
 	/* reclaim/compaction might need reclaim to continue */
-	if (should_continue_reclaim(zone, nr_reclaimed,
+	if (should_continue_reclaim(mz, nr_reclaimed,
 					sc->nr_scanned - nr_scanned, sc))
 		goto restart;
 
 	throttle_vm_writeout(sc->gfp_mask);
 }
 
+static void shrink_zone(int priority, struct zone *zone,
+			struct scan_control *sc)
+{
+	struct mem_cgroup_zone mz = {
+		.mem_cgroup = sc->target_mem_cgroup,
+		.zone = zone,
+	};
+
+	shrink_mem_cgroup_zone(priority, &mz, sc);
+}
+
 /*
  * This is the direct reclaim path, for page-allocating processes.  We only
  * try to reclaim pages from zones which will satisfy the caller's allocation
@@ -2206,7 +2229,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
 	for (priority = DEF_PRIORITY; priority >= 0; priority--) {
 		sc->nr_scanned = 0;
 		if (!priority)
-			disable_swap_token(sc->mem_cgroup);
+			disable_swap_token(sc->target_mem_cgroup);
 		shrink_zones(priority, zonelist, sc);
 		/*
 		 * Don't shrink slabs when reclaiming memory from
@@ -2290,7 +2313,7 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
 		.may_unmap = 1,
 		.may_swap = 1,
 		.order = order,
-		.mem_cgroup = NULL,
+		.target_mem_cgroup = NULL,
 		.nodemask = nodemask,
 	};
 	struct shrink_control shrink = {
@@ -2322,7 +2345,7 @@ unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
 		.may_unmap = 1,
 		.may_swap = !noswap,
 		.order = 0,
-		.mem_cgroup = mem,
+		.target_mem_cgroup = mem,
 	};
 
 	sc.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) |
@@ -2360,7 +2383,7 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
 		.may_swap = !noswap,
 		.nr_to_reclaim = SWAP_CLUSTER_MAX,
 		.order = 0,
-		.mem_cgroup = mem_cont,
+		.target_mem_cgroup = mem_cont,
 		.nodemask = NULL, /* we don't care the placement */
 		.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) |
 				(GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK),
@@ -2390,6 +2413,18 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
 }
 #endif
 
+static void age_active_anon(struct zone *zone, struct scan_control *sc,
+			    int priority)
+{
+	struct mem_cgroup_zone mz = {
+		.mem_cgroup = NULL,
+		.zone = zone,
+	};
+
+	if (inactive_anon_is_low(&mz))
+		shrink_active_list(SWAP_CLUSTER_MAX, &mz, sc, priority, 0);
+}
+
 /*
  * pgdat_balanced is used when checking if a node is balanced for high-order
  * allocations. Only zones that meet watermarks and are in a zone allowed
@@ -2510,7 +2545,7 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
 		 */
 		.nr_to_reclaim = ULONG_MAX,
 		.order = order,
-		.mem_cgroup = NULL,
+		.target_mem_cgroup = NULL,
 	};
 	struct shrink_control shrink = {
 		.gfp_mask = sc.gfp_mask,
@@ -2549,9 +2584,7 @@ loop_again:
 			 * Do some background aging of the anon list, to give
 			 * pages a chance to be referenced before reclaiming.
 			 */
-			if (inactive_anon_is_low(zone, &sc))
-				shrink_active_list(SWAP_CLUSTER_MAX, zone,
-							&sc, priority, 0);
+			age_active_anon(zone, &sc, priority);
 
 			if (!zone_watermark_ok_safe(zone, order,
 					high_wmark_pages(zone), 0, 0)) {
-- 
1.7.6.2


^ permalink raw reply related	[flat|nested] 32+ messages in thread
* [patch 03/10] mm: vmscan: distinguish between memcg triggering reclaim and memcg being scanned
@ 2011-09-29 21:00   ` Johannes Weiner
  0 siblings, 0 replies; 32+ messages in thread
From: Johannes Weiner @ 2011-09-29 21:00 UTC (permalink / raw)
  To: Andrew Morton
  Cc: KAMEZAWA Hiroyuki, Michal Hocko, Kirill A. Shutemov,
	Daisuke Nishimura, Balbir Singh, Ying Han, Greg Thelen,
	Michel Lespinasse, Rik van Riel, Minchan Kim, Christoph Hellwig,
	Hugh Dickins, linux-mm, linux-kernel

Memory cgroup hierarchies are currently handled completely outside of
the traditional reclaim code, which is invoked with a single memory
cgroup as an argument for the whole call stack.

Subsequent patches will switch this code to do hierarchical reclaim,
so there needs to be a distinction between a) the memory cgroup that
is triggering reclaim due to hitting its limit and b) the memory
cgroup that is being scanned as a child of a).

This patch introduces a struct mem_cgroup_zone that contains the
combination of the memory cgroup and the zone being scanned, which is
then passed down the stack instead of the zone argument.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
---
 mm/vmscan.c |  249 +++++++++++++++++++++++++++++++++--------------------------
 1 files changed, 141 insertions(+), 108 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 4bb7f78..88ccdd8 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -103,8 +103,11 @@ struct scan_control {
 	 */
 	reclaim_mode_t reclaim_mode;
 
-	/* Which cgroup do we reclaim from */
-	struct mem_cgroup *mem_cgroup;
+	/*
+	 * The memory cgroup that hit its limit and as a result is the
+	 * primary target of this reclaim invocation.
+	 */
+	struct mem_cgroup *target_mem_cgroup;
 
 	/*
 	 * Nodemask of nodes allowed by the caller. If NULL, all nodes
@@ -113,6 +116,11 @@ struct scan_control {
 	nodemask_t	*nodemask;
 };
 
+struct mem_cgroup_zone {
+	struct mem_cgroup *mem_cgroup;
+	struct zone *zone;
+};
+
 #define lru_to_page(_head) (list_entry((_head)->prev, struct page, lru))
 
 #ifdef ARCH_HAS_PREFETCH
@@ -155,12 +163,12 @@ static DECLARE_RWSEM(shrinker_rwsem);
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR
 static bool global_reclaim(struct scan_control *sc)
 {
-	return !sc->mem_cgroup;
+	return !sc->target_mem_cgroup;
 }
 
-static bool scanning_global_lru(struct scan_control *sc)
+static bool scanning_global_lru(struct mem_cgroup_zone *mz)
 {
-	return !sc->mem_cgroup;
+	return !mz->mem_cgroup;
 }
 #else
 static bool global_reclaim(struct scan_control *sc)
@@ -168,29 +176,30 @@ static bool global_reclaim(struct scan_control *sc)
 	return true;
 }
 
-static bool scanning_global_lru(struct scan_control *sc)
+static bool scanning_global_lru(struct mem_cgroup_zone *mz)
 {
 	return true;
 }
 #endif
 
-static struct zone_reclaim_stat *get_reclaim_stat(struct zone *zone,
-						  struct scan_control *sc)
+static struct zone_reclaim_stat *get_reclaim_stat(struct mem_cgroup_zone *mz)
 {
-	if (!scanning_global_lru(sc))
-		return mem_cgroup_get_reclaim_stat(sc->mem_cgroup, zone);
+	if (!scanning_global_lru(mz))
+		return mem_cgroup_get_reclaim_stat(mz->mem_cgroup, mz->zone);
 
-	return &zone->reclaim_stat;
+	return &mz->zone->reclaim_stat;
 }
 
-static unsigned long zone_nr_lru_pages(struct zone *zone,
-				struct scan_control *sc, enum lru_list lru)
+static unsigned long zone_nr_lru_pages(struct mem_cgroup_zone *mz,
+				       enum lru_list lru)
 {
-	if (!scanning_global_lru(sc))
-		return mem_cgroup_zone_nr_lru_pages(sc->mem_cgroup,
-				zone_to_nid(zone), zone_idx(zone), BIT(lru));
+	if (!scanning_global_lru(mz))
+		return mem_cgroup_zone_nr_lru_pages(mz->mem_cgroup,
+						    zone_to_nid(mz->zone),
+						    zone_idx(mz->zone),
+						    BIT(lru));
 
-	return zone_page_state(zone, NR_LRU_BASE + lru);
+	return zone_page_state(mz->zone, NR_LRU_BASE + lru);
 }
 
 
@@ -692,12 +701,13 @@ enum page_references {
 };
 
 static enum page_references page_check_references(struct page *page,
+						  struct mem_cgroup_zone *mz,
 						  struct scan_control *sc)
 {
 	int referenced_ptes, referenced_page;
 	unsigned long vm_flags;
 
-	referenced_ptes = page_referenced(page, 1, sc->mem_cgroup, &vm_flags);
+	referenced_ptes = page_referenced(page, 1, mz->mem_cgroup, &vm_flags);
 	referenced_page = TestClearPageReferenced(page);
 
 	/* Lumpy reclaim - ignore references */
@@ -771,7 +781,7 @@ static noinline_for_stack void free_page_list(struct list_head *free_pages)
  * shrink_page_list() returns the number of reclaimed pages
  */
 static unsigned long shrink_page_list(struct list_head *page_list,
-				      struct zone *zone,
+				      struct mem_cgroup_zone *mz,
 				      struct scan_control *sc,
 				      int priority,
 				      unsigned long *ret_nr_dirty,
@@ -802,7 +812,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 			goto keep;
 
 		VM_BUG_ON(PageActive(page));
-		VM_BUG_ON(page_zone(page) != zone);
+		VM_BUG_ON(page_zone(page) != mz->zone);
 
 		sc->nr_scanned++;
 
@@ -836,7 +846,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 			}
 		}
 
-		references = page_check_references(page, sc);
+		references = page_check_references(page, mz, sc);
 		switch (references) {
 		case PAGEREF_ACTIVATE:
 			goto activate_locked;
@@ -1028,7 +1038,7 @@ keep_lumpy:
 	 * will encounter the same problem
 	 */
 	if (nr_dirty && nr_dirty == nr_congested && global_reclaim(sc))
-		zone_set_flag(zone, ZONE_CONGESTED);
+		zone_set_flag(mz->zone, ZONE_CONGESTED);
 
 	free_page_list(&free_pages);
 
@@ -1364,13 +1374,14 @@ static int too_many_isolated(struct zone *zone, int file,
  * TODO: Try merging with migrations version of putback_lru_pages
  */
 static noinline_for_stack void
-putback_lru_pages(struct zone *zone, struct scan_control *sc,
-				unsigned long nr_anon, unsigned long nr_file,
-				struct list_head *page_list)
+putback_lru_pages(struct mem_cgroup_zone *mz, struct scan_control *sc,
+		  unsigned long nr_anon, unsigned long nr_file,
+		  struct list_head *page_list)
 {
 	struct page *page;
 	struct pagevec pvec;
-	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
+	struct zone *zone = mz->zone;
+	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(mz);
 
 	pagevec_init(&pvec, 1);
 
@@ -1410,15 +1421,17 @@ putback_lru_pages(struct zone *zone, struct scan_control *sc,
 	pagevec_release(&pvec);
 }
 
-static noinline_for_stack void update_isolated_counts(struct zone *zone,
-					struct scan_control *sc,
-					unsigned long *nr_anon,
-					unsigned long *nr_file,
-					struct list_head *isolated_list)
+static noinline_for_stack void
+update_isolated_counts(struct mem_cgroup_zone *mz,
+		       struct scan_control *sc,
+		       unsigned long *nr_anon,
+		       unsigned long *nr_file,
+		       struct list_head *isolated_list)
 {
 	unsigned long nr_active;
+	struct zone *zone = mz->zone;
 	unsigned int count[NR_LRU_LISTS] = { 0, };
-	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
+	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(mz);
 
 	nr_active = clear_active_flags(isolated_list, count);
 	__count_vm_events(PGDEACTIVATE, nr_active);
@@ -1487,8 +1500,8 @@ static inline bool should_reclaim_stall(unsigned long nr_taken,
  * of reclaimed pages
  */
 static noinline_for_stack unsigned long
-shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
-			struct scan_control *sc, int priority, int file)
+shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz,
+		     struct scan_control *sc, int priority, int file)
 {
 	LIST_HEAD(page_list);
 	unsigned long nr_scanned;
@@ -1499,6 +1512,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
 	unsigned long nr_dirty = 0;
 	unsigned long nr_writeback = 0;
 	isolate_mode_t reclaim_mode = ISOLATE_INACTIVE;
+	struct zone *zone = mz->zone;
 
 	while (unlikely(too_many_isolated(zone, file, sc))) {
 		congestion_wait(BLK_RW_ASYNC, HZ/10);
@@ -1521,13 +1535,13 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
 
 	spin_lock_irq(&zone->lru_lock);
 
-	if (scanning_global_lru(sc)) {
+	if (scanning_global_lru(mz)) {
 		nr_taken = isolate_pages_global(nr_to_scan, &page_list,
 			&nr_scanned, sc->order, reclaim_mode, zone, 0, file);
 	} else {
 		nr_taken = mem_cgroup_isolate_pages(nr_to_scan, &page_list,
 			&nr_scanned, sc->order, reclaim_mode, zone,
-			sc->mem_cgroup, 0, file);
+			mz->mem_cgroup, 0, file);
 	}
 	if (global_reclaim(sc)) {
 		zone->pages_scanned += nr_scanned;
@@ -1544,17 +1558,17 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
 		return 0;
 	}
 
-	update_isolated_counts(zone, sc, &nr_anon, &nr_file, &page_list);
+	update_isolated_counts(mz, sc, &nr_anon, &nr_file, &page_list);
 
 	spin_unlock_irq(&zone->lru_lock);
 
-	nr_reclaimed = shrink_page_list(&page_list, zone, sc, priority,
+	nr_reclaimed = shrink_page_list(&page_list, mz, sc, priority,
 						&nr_dirty, &nr_writeback);
 
 	/* Check if we should syncronously wait for writeback */
 	if (should_reclaim_stall(nr_taken, nr_reclaimed, priority, sc)) {
 		set_reclaim_mode(priority, sc, true);
-		nr_reclaimed += shrink_page_list(&page_list, zone, sc,
+		nr_reclaimed += shrink_page_list(&page_list, mz, sc,
 					priority, &nr_dirty, &nr_writeback);
 	}
 
@@ -1563,7 +1577,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
 		__count_vm_events(KSWAPD_STEAL, nr_reclaimed);
 	__count_zone_vm_events(PGSTEAL, zone, nr_reclaimed);
 
-	putback_lru_pages(zone, sc, nr_anon, nr_file, &page_list);
+	putback_lru_pages(mz, sc, nr_anon, nr_file, &page_list);
 
 	/*
 	 * If we have encountered a high number of dirty pages under writeback
@@ -1634,8 +1648,10 @@ static void move_active_pages_to_lru(struct zone *zone,
 		__count_vm_events(PGDEACTIVATE, pgmoved);
 }
 
-static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
-			struct scan_control *sc, int priority, int file)
+static void shrink_active_list(unsigned long nr_pages,
+			       struct mem_cgroup_zone *mz,
+			       struct scan_control *sc,
+			       int priority, int file)
 {
 	unsigned long nr_taken;
 	unsigned long pgscanned;
@@ -1644,9 +1660,10 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 	LIST_HEAD(l_active);
 	LIST_HEAD(l_inactive);
 	struct page *page;
-	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
+	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(mz);
 	unsigned long nr_rotated = 0;
 	isolate_mode_t reclaim_mode = ISOLATE_ACTIVE;
+	struct zone *zone = mz->zone;
 
 	lru_add_drain();
 
@@ -1656,7 +1673,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 		reclaim_mode |= ISOLATE_CLEAN;
 
 	spin_lock_irq(&zone->lru_lock);
-	if (scanning_global_lru(sc)) {
+	if (scanning_global_lru(mz)) {
 		nr_taken = isolate_pages_global(nr_pages, &l_hold,
 						&pgscanned, sc->order,
 						reclaim_mode, zone,
@@ -1665,7 +1682,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 		nr_taken = mem_cgroup_isolate_pages(nr_pages, &l_hold,
 						&pgscanned, sc->order,
 						reclaim_mode, zone,
-						sc->mem_cgroup, 1, file);
+						mz->mem_cgroup, 1, file);
 	}
 
 	if (global_reclaim(sc))
@@ -1691,7 +1708,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 			continue;
 		}
 
-		if (page_referenced(page, 0, sc->mem_cgroup, &vm_flags)) {
+		if (page_referenced(page, 0, mz->mem_cgroup, &vm_flags)) {
 			nr_rotated += hpage_nr_pages(page);
 			/*
 			 * Identify referenced, file-backed active pages and
@@ -1754,10 +1771,8 @@ static int inactive_anon_is_low_global(struct zone *zone)
  * Returns true if the zone does not have enough inactive anon pages,
  * meaning some active anon pages need to be deactivated.
  */
-static int inactive_anon_is_low(struct zone *zone, struct scan_control *sc)
+static int inactive_anon_is_low(struct mem_cgroup_zone *mz)
 {
-	int low;
-
 	/*
 	 * If we don't have swap space, anonymous page deactivation
 	 * is pointless.
@@ -1765,15 +1780,14 @@ static int inactive_anon_is_low(struct zone *zone, struct scan_control *sc)
 	if (!total_swap_pages)
 		return 0;
 
-	if (scanning_global_lru(sc))
-		low = inactive_anon_is_low_global(zone);
-	else
-		low = mem_cgroup_inactive_anon_is_low(sc->mem_cgroup, zone);
-	return low;
+	if (!scanning_global_lru(mz))
+		return mem_cgroup_inactive_anon_is_low(mz->mem_cgroup,
+						       mz->zone);
+
+	return inactive_anon_is_low_global(mz->zone);
 }
 #else
-static inline int inactive_anon_is_low(struct zone *zone,
-					struct scan_control *sc)
+static inline int inactive_anon_is_low(struct mem_cgroup_zone *mz)
 {
 	return 0;
 }
@@ -1791,8 +1805,7 @@ static int inactive_file_is_low_global(struct zone *zone)
 
 /**
  * inactive_file_is_low - check if file pages need to be deactivated
- * @zone: zone to check
- * @sc:   scan control of this context
+ * @mz: memory cgroup and zone to check
  *
  * When the system is doing streaming IO, memory pressure here
  * ensures that active file pages get deactivated, until more
@@ -1804,45 +1817,44 @@ static int inactive_file_is_low_global(struct zone *zone)
  * This uses a different ratio than the anonymous pages, because
  * the page cache uses a use-once replacement algorithm.
  */
-static int inactive_file_is_low(struct zone *zone, struct scan_control *sc)
+static int inactive_file_is_low(struct mem_cgroup_zone *mz)
 {
-	int low;
+	if (!scanning_global_lru(mz))
+		return mem_cgroup_inactive_file_is_low(mz->mem_cgroup,
+						       mz->zone);
 
-	if (scanning_global_lru(sc))
-		low = inactive_file_is_low_global(zone);
-	else
-		low = mem_cgroup_inactive_file_is_low(sc->mem_cgroup, zone);
-	return low;
+	return inactive_file_is_low_global(mz->zone);
 }
 
-static int inactive_list_is_low(struct zone *zone, struct scan_control *sc,
-				int file)
+static int inactive_list_is_low(struct mem_cgroup_zone *mz, int file)
 {
 	if (file)
-		return inactive_file_is_low(zone, sc);
+		return inactive_file_is_low(mz);
 	else
-		return inactive_anon_is_low(zone, sc);
+		return inactive_anon_is_low(mz);
 }
 
 static unsigned long shrink_list(enum lru_list lru, unsigned long nr_to_scan,
-	struct zone *zone, struct scan_control *sc, int priority)
+				 struct mem_cgroup_zone *mz,
+				 struct scan_control *sc, int priority)
 {
 	int file = is_file_lru(lru);
 
 	if (is_active_lru(lru)) {
-		if (inactive_list_is_low(zone, sc, file))
-		    shrink_active_list(nr_to_scan, zone, sc, priority, file);
+		if (inactive_list_is_low(mz, file))
+		    shrink_active_list(nr_to_scan, mz, sc, priority, file);
 		return 0;
 	}
 
-	return shrink_inactive_list(nr_to_scan, zone, sc, priority, file);
+	return shrink_inactive_list(nr_to_scan, mz, sc, priority, file);
 }
 
-static int vmscan_swappiness(struct scan_control *sc)
+static int vmscan_swappiness(struct mem_cgroup_zone *mz,
+			     struct scan_control *sc)
 {
 	if (global_reclaim(sc))
 		return vm_swappiness;
-	return mem_cgroup_swappiness(sc->mem_cgroup);
+	return mem_cgroup_swappiness(mz->mem_cgroup);
 }
 
 /*
@@ -1853,13 +1865,13 @@ static int vmscan_swappiness(struct scan_control *sc)
  *
  * nr[0] = anon pages to scan; nr[1] = file pages to scan
  */
-static void get_scan_count(struct zone *zone, struct scan_control *sc,
-					unsigned long *nr, int priority)
+static void get_scan_count(struct mem_cgroup_zone *mz, struct scan_control *sc,
+			   unsigned long *nr, int priority)
 {
 	unsigned long anon, file, free;
 	unsigned long anon_prio, file_prio;
 	unsigned long ap, fp;
-	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
+	struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(mz);
 	u64 fraction[2], denominator;
 	enum lru_list l;
 	int noswap = 0;
@@ -1889,16 +1901,16 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
 		goto out;
 	}
 
-	anon  = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_ANON) +
-		zone_nr_lru_pages(zone, sc, LRU_INACTIVE_ANON);
-	file  = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_FILE) +
-		zone_nr_lru_pages(zone, sc, LRU_INACTIVE_FILE);
+	anon  = zone_nr_lru_pages(mz, LRU_ACTIVE_ANON) +
+		zone_nr_lru_pages(mz, LRU_INACTIVE_ANON);
+	file  = zone_nr_lru_pages(mz, LRU_ACTIVE_FILE) +
+		zone_nr_lru_pages(mz, LRU_INACTIVE_FILE);
 
 	if (global_reclaim(sc)) {
-		free  = zone_page_state(zone, NR_FREE_PAGES);
+		free  = zone_page_state(mz->zone, NR_FREE_PAGES);
 		/* If we have very few page cache pages,
 		   force-scan anon pages. */
-		if (unlikely(file + free <= high_wmark_pages(zone))) {
+		if (unlikely(file + free <= high_wmark_pages(mz->zone))) {
 			fraction[0] = 1;
 			fraction[1] = 0;
 			denominator = 1;
@@ -1910,8 +1922,8 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
 	 * With swappiness at 100, anonymous and file have the same priority.
 	 * This scanning priority is essentially the inverse of IO cost.
 	 */
-	anon_prio = vmscan_swappiness(sc);
-	file_prio = 200 - vmscan_swappiness(sc);
+	anon_prio = vmscan_swappiness(mz, sc);
+	file_prio = 200 - vmscan_swappiness(mz, sc);
 
 	/*
 	 * OK, so we have swap space and a fair amount of page cache
@@ -1924,7 +1936,7 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
 	 *
 	 * anon in [0], file in [1]
 	 */
-	spin_lock_irq(&zone->lru_lock);
+	spin_lock_irq(&mz->zone->lru_lock);
 	if (unlikely(reclaim_stat->recent_scanned[0] > anon / 4)) {
 		reclaim_stat->recent_scanned[0] /= 2;
 		reclaim_stat->recent_rotated[0] /= 2;
@@ -1945,7 +1957,7 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
 
 	fp = (file_prio + 1) * (reclaim_stat->recent_scanned[1] + 1);
 	fp /= reclaim_stat->recent_rotated[1] + 1;
-	spin_unlock_irq(&zone->lru_lock);
+	spin_unlock_irq(&mz->zone->lru_lock);
 
 	fraction[0] = ap;
 	fraction[1] = fp;
@@ -1955,7 +1967,7 @@ out:
 		int file = is_file_lru(l);
 		unsigned long scan;
 
-		scan = zone_nr_lru_pages(zone, sc, l);
+		scan = zone_nr_lru_pages(mz, l);
 		if (priority || noswap) {
 			scan >>= priority;
 			if (!scan && force_scan)
@@ -1973,7 +1985,7 @@ out:
  * back to the allocator and call try_to_compact_zone(), we ensure that
  * there are enough free pages for it to be likely successful
  */
-static inline bool should_continue_reclaim(struct zone *zone,
+static inline bool should_continue_reclaim(struct mem_cgroup_zone *mz,
 					unsigned long nr_reclaimed,
 					unsigned long nr_scanned,
 					struct scan_control *sc)
@@ -2013,14 +2025,14 @@ static inline bool should_continue_reclaim(struct zone *zone,
 	 * inactive lists are large enough, continue reclaiming
 	 */
 	pages_for_compaction = (2UL << sc->order);
-	inactive_lru_pages = zone_nr_lru_pages(zone, sc, LRU_INACTIVE_ANON) +
-				zone_nr_lru_pages(zone, sc, LRU_INACTIVE_FILE);
+	inactive_lru_pages = zone_nr_lru_pages(mz, LRU_INACTIVE_ANON) +
+				zone_nr_lru_pages(mz, LRU_INACTIVE_FILE);
 	if (sc->nr_reclaimed < pages_for_compaction &&
 			inactive_lru_pages > pages_for_compaction)
 		return true;
 
 	/* If compaction would go ahead or the allocation would succeed, stop */
-	switch (compaction_suitable(zone, sc->order)) {
+	switch (compaction_suitable(mz->zone, sc->order)) {
 	case COMPACT_PARTIAL:
 	case COMPACT_CONTINUE:
 		return false;
@@ -2032,8 +2044,8 @@ static inline bool should_continue_reclaim(struct zone *zone,
 /*
  * This is a basic per-zone page freer.  Used by both kswapd and direct reclaim.
  */
-static void shrink_zone(int priority, struct zone *zone,
-				struct scan_control *sc)
+static void shrink_mem_cgroup_zone(int priority, struct mem_cgroup_zone *mz,
+				   struct scan_control *sc)
 {
 	unsigned long nr[NR_LRU_LISTS];
 	unsigned long nr_to_scan;
@@ -2045,7 +2057,7 @@ static void shrink_zone(int priority, struct zone *zone,
 restart:
 	nr_reclaimed = 0;
 	nr_scanned = sc->nr_scanned;
-	get_scan_count(zone, sc, nr, priority);
+	get_scan_count(mz, sc, nr, priority);
 
 	blk_start_plug(&plug);
 	while (nr[LRU_INACTIVE_ANON] || nr[LRU_ACTIVE_FILE] ||
@@ -2057,7 +2069,7 @@ restart:
 				nr[l] -= nr_to_scan;
 
 				nr_reclaimed += shrink_list(l, nr_to_scan,
-							    zone, sc, priority);
+							    mz, sc, priority);
 			}
 		}
 		/*
@@ -2078,17 +2090,28 @@ restart:
 	 * Even if we did not try to evict anon pages at all, we want to
 	 * rebalance the anon lru active/inactive ratio.
 	 */
-	if (inactive_anon_is_low(zone, sc))
-		shrink_active_list(SWAP_CLUSTER_MAX, zone, sc, priority, 0);
+	if (inactive_anon_is_low(mz))
+		shrink_active_list(SWAP_CLUSTER_MAX, mz, sc, priority, 0);
 
 	/* reclaim/compaction might need reclaim to continue */
-	if (should_continue_reclaim(zone, nr_reclaimed,
+	if (should_continue_reclaim(mz, nr_reclaimed,
 					sc->nr_scanned - nr_scanned, sc))
 		goto restart;
 
 	throttle_vm_writeout(sc->gfp_mask);
 }
 
+static void shrink_zone(int priority, struct zone *zone,
+			struct scan_control *sc)
+{
+	struct mem_cgroup_zone mz = {
+		.mem_cgroup = sc->target_mem_cgroup,
+		.zone = zone,
+	};
+
+	shrink_mem_cgroup_zone(priority, &mz, sc);
+}
+
 /*
  * This is the direct reclaim path, for page-allocating processes.  We only
  * try to reclaim pages from zones which will satisfy the caller's allocation
@@ -2206,7 +2229,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
 	for (priority = DEF_PRIORITY; priority >= 0; priority--) {
 		sc->nr_scanned = 0;
 		if (!priority)
-			disable_swap_token(sc->mem_cgroup);
+			disable_swap_token(sc->target_mem_cgroup);
 		shrink_zones(priority, zonelist, sc);
 		/*
 		 * Don't shrink slabs when reclaiming memory from
@@ -2290,7 +2313,7 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
 		.may_unmap = 1,
 		.may_swap = 1,
 		.order = order,
-		.mem_cgroup = NULL,
+		.target_mem_cgroup = NULL,
 		.nodemask = nodemask,
 	};
 	struct shrink_control shrink = {
@@ -2322,7 +2345,7 @@ unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
 		.may_unmap = 1,
 		.may_swap = !noswap,
 		.order = 0,
-		.mem_cgroup = mem,
+		.target_mem_cgroup = mem,
 	};
 
 	sc.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) |
@@ -2360,7 +2383,7 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
 		.may_swap = !noswap,
 		.nr_to_reclaim = SWAP_CLUSTER_MAX,
 		.order = 0,
-		.mem_cgroup = mem_cont,
+		.target_mem_cgroup = mem_cont,
 		.nodemask = NULL, /* we don't care the placement */
 		.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) |
 				(GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK),
@@ -2390,6 +2413,18 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
 }
 #endif
 
+static void age_active_anon(struct zone *zone, struct scan_control *sc,
+			    int priority)
+{
+	struct mem_cgroup_zone mz = {
+		.mem_cgroup = NULL,
+		.zone = zone,
+	};
+
+	if (inactive_anon_is_low(&mz))
+		shrink_active_list(SWAP_CLUSTER_MAX, &mz, sc, priority, 0);
+}
+
 /*
  * pgdat_balanced is used when checking if a node is balanced for high-order
  * allocations. Only zones that meet watermarks and are in a zone allowed
@@ -2510,7 +2545,7 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
 		 */
 		.nr_to_reclaim = ULONG_MAX,
 		.order = order,
-		.mem_cgroup = NULL,
+		.target_mem_cgroup = NULL,
 	};
 	struct shrink_control shrink = {
 		.gfp_mask = sc.gfp_mask,
@@ -2549,9 +2584,7 @@ loop_again:
 			 * Do some background aging of the anon list, to give
 			 * pages a chance to be referenced before reclaiming.
 			 */
-			if (inactive_anon_is_low(zone, &sc))
-				shrink_active_list(SWAP_CLUSTER_MAX, zone,
-							&sc, priority, 0);
+			age_active_anon(zone, &sc, priority);
 
 			if (!zone_watermark_ok_safe(zone, order,
 					high_wmark_pages(zone), 0, 0)) {
-- 
1.7.6.2

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^ permalink raw reply related	[flat|nested] 32+ messages in thread
end of thread, other threads:[~2011-11-09 13:16 UTC | newest]

Thread overview: 32+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2011-11-08 21:23 [patch 00/10] memcg naturalization -rc5 Johannes Weiner
2011-11-08 21:23 ` Johannes Weiner
2011-11-08 21:23 ` [patch 01/10] mm: memcg: consolidate hierarchy iteration primitives Johannes Weiner
2011-11-08 21:23   ` Johannes Weiner
2011-11-08 21:23 ` [patch 02/10] mm: vmscan: distinguish global reclaim from global LRU scanning Johannes Weiner
2011-11-08 21:23   ` Johannes Weiner
2011-11-08 21:23 ` [patch 03/10] mm: vmscan: distinguish between memcg triggering reclaim and memcg being scanned Johannes Weiner
2011-11-08 21:23   ` Johannes Weiner
2011-11-08 21:23 ` [patch 04/10] mm: memcg: per-priority per-zone hierarchy scan generations Johannes Weiner
2011-11-08 21:23   ` Johannes Weiner
2011-11-08 21:23 ` [patch 05/10] mm: move memcg hierarchy reclaim to generic reclaim code Johannes Weiner
2011-11-08 21:23   ` Johannes Weiner
2011-11-08 21:23 ` [patch 06/10] mm: memcg: remove optimization of keeping the root_mem_cgroup LRU lists empty Johannes Weiner
2011-11-08 21:23   ` Johannes Weiner
2011-11-08 21:23 ` [patch 07/10] mm: vmscan: convert global reclaim to per-memcg LRU lists Johannes Weiner
2011-11-08 21:23   ` Johannes Weiner
2011-11-08 21:23 ` [patch 08/10] mm: collect LRU list heads into struct lruvec Johannes Weiner
2011-11-08 21:23   ` Johannes Weiner
2011-11-08 21:23 ` [patch 09/10] mm: make per-memcg LRU lists exclusive Johannes Weiner
2011-11-08 21:23   ` Johannes Weiner
2011-11-08 21:23 ` [patch 10/10] mm: memcg: remove unused node/section info from pc->flags Johannes Weiner
2011-11-08 21:23   ` Johannes Weiner
2011-11-09  5:18   ` [PATCH mm] mm: memcg: remove unused node/section info from pc->flags fix Hugh Dickins
2011-11-09  5:18     ` Hugh Dickins
2011-11-09  5:27     ` KAMEZAWA Hiroyuki
2011-11-09  5:27       ` KAMEZAWA Hiroyuki
2011-11-09 13:14     ` Johannes Weiner
2011-11-09 13:14       ` Johannes Weiner
2011-11-09  0:05 ` [patch 00/10] memcg naturalization -rc5 KAMEZAWA Hiroyuki
2011-11-09  0:05   ` KAMEZAWA Hiroyuki
  -- strict thread matches above, loose matches on Subject: below --
2011-09-29 21:00 [patch 00/10] memcg naturalization -rc4 Johannes Weiner
2011-09-29 21:00 ` [patch 03/10] mm: vmscan: distinguish between memcg triggering reclaim and memcg being scanned Johannes Weiner
2011-09-29 21:00   ` Johannes Weiner

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