[PATCH v2 0/5] A few cleanup patches for hugetlb_cgroup

[PATCH v2 0/5] A few cleanup patches for hugetlb_cgroup

[Miaohe Lin]

Hi everyone,
This series contains a few cleaup patches to remove unneeded check,
use helper macro, remove unneeded return value and so on. More details
can be found in the respective changelogs.
Thanks!
---
v2:
 drop patch 2/6 per Mina
 collect Reviewed-by tag per Mina and Mike. Thanks for review!
---
Miaohe Lin (5):
  hugetlb_cgroup: remove unneeded nr_pages > 0 check
  hugetlb_cgroup: hugetlbfs: use helper macro SZ_1{K,M,G}
  hugetlb_cgroup: remove unneeded return value
  hugetlb_cgroup: use helper macro NUMA_NO_NODE
  hugetlb_cgroup: use helper for_each_hstate and hstate_index

 include/linux/hugetlb_cgroup.h | 19 ++++++++-----------
 mm/hugetlb_cgroup.c            | 27 ++++++++++++---------------
 2 files changed, 20 insertions(+), 26 deletions(-)

-- 
2.23.0

[PATCH v2 1/5] hugetlb_cgroup: remove unneeded nr_pages > 0 check

[Miaohe Lin]

When code reaches here, nr_pages must be > 0. Remove unneeded nr_pages > 0
check to simplify the code.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mina Almasry <almasrymina@google.com>
---
 mm/hugetlb_cgroup.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
index c86691c431fd..d16eb00c947d 100644
--- a/mm/hugetlb_cgroup.c
+++ b/mm/hugetlb_cgroup.c
@@ -442,7 +442,7 @@ void hugetlb_cgroup_uncharge_file_region(struct resv_map *resv,
 	if (hugetlb_cgroup_disabled() || !resv || !rg || !nr_pages)
 		return;
 
-	if (rg->reservation_counter && resv->pages_per_hpage && nr_pages > 0 &&
+	if (rg->reservation_counter && resv->pages_per_hpage &&
 	    !resv->reservation_counter) {
 		page_counter_uncharge(rg->reservation_counter,
 				      nr_pages * resv->pages_per_hpage);
-- 
2.23.0

[PATCH v2 2/5] hugetlb_cgroup: hugetlbfs: use helper macro SZ_1{K,M,G}

[Miaohe Lin]

Use helper macro SZ_1K, SZ_1M and SZ_1G to do the size conversion. Minor
readability improvement.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mina Almasry <almasrymina@google.com>
---
 mm/hugetlb_cgroup.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
index d16eb00c947d..01a709468937 100644
--- a/mm/hugetlb_cgroup.c
+++ b/mm/hugetlb_cgroup.c
@@ -675,12 +675,12 @@ static ssize_t hugetlb_cgroup_reset(struct kernfs_open_file *of,
 
 static char *mem_fmt(char *buf, int size, unsigned long hsize)
 {
-	if (hsize >= (1UL << 30))
-		snprintf(buf, size, "%luGB", hsize >> 30);
-	else if (hsize >= (1UL << 20))
-		snprintf(buf, size, "%luMB", hsize >> 20);
+	if (hsize >= SZ_1G)
+		snprintf(buf, size, "%luGB", hsize / SZ_1G);
+	else if (hsize >= SZ_1M)
+		snprintf(buf, size, "%luMB", hsize / SZ_1M);
 	else
-		snprintf(buf, size, "%luKB", hsize >> 10);
+		snprintf(buf, size, "%luKB", hsize / SZ_1K);
 	return buf;
 }
 
-- 
2.23.0

[PATCH v2 3/5] hugetlb_cgroup: remove unneeded return value

[Miaohe Lin]

The return value of set_hugetlb_cgroup and set_hugetlb_cgroup_rsvd are
always ignored. Remove them to clean up the code.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
---
 include/linux/hugetlb_cgroup.h | 19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)

diff --git a/include/linux/hugetlb_cgroup.h b/include/linux/hugetlb_cgroup.h
index 379344828e78..630cd255d0cf 100644
--- a/include/linux/hugetlb_cgroup.h
+++ b/include/linux/hugetlb_cgroup.h
@@ -90,32 +90,31 @@ hugetlb_cgroup_from_page_rsvd(struct page *page)
 	return __hugetlb_cgroup_from_page(page, true);
 }
 
-static inline int __set_hugetlb_cgroup(struct page *page,
+static inline void __set_hugetlb_cgroup(struct page *page,
 				       struct hugetlb_cgroup *h_cg, bool rsvd)
 {
 	VM_BUG_ON_PAGE(!PageHuge(page), page);
 
 	if (compound_order(page) < HUGETLB_CGROUP_MIN_ORDER)
-		return -1;
+		return;
 	if (rsvd)
 		set_page_private(page + SUBPAGE_INDEX_CGROUP_RSVD,
 				 (unsigned long)h_cg);
 	else
 		set_page_private(page + SUBPAGE_INDEX_CGROUP,
 				 (unsigned long)h_cg);
-	return 0;
 }
 
-static inline int set_hugetlb_cgroup(struct page *page,
+static inline void set_hugetlb_cgroup(struct page *page,
 				     struct hugetlb_cgroup *h_cg)
 {
-	return __set_hugetlb_cgroup(page, h_cg, false);
+	__set_hugetlb_cgroup(page, h_cg, false);
 }
 
-static inline int set_hugetlb_cgroup_rsvd(struct page *page,
+static inline void set_hugetlb_cgroup_rsvd(struct page *page,
 					  struct hugetlb_cgroup *h_cg)
 {
-	return __set_hugetlb_cgroup(page, h_cg, true);
+	__set_hugetlb_cgroup(page, h_cg, true);
 }
 
 static inline bool hugetlb_cgroup_disabled(void)
@@ -199,16 +198,14 @@ hugetlb_cgroup_from_page_rsvd(struct page *page)
 	return NULL;
 }
 
-static inline int set_hugetlb_cgroup(struct page *page,
+static inline void set_hugetlb_cgroup(struct page *page,
 				     struct hugetlb_cgroup *h_cg)
 {
-	return 0;
 }
 
-static inline int set_hugetlb_cgroup_rsvd(struct page *page,
+static inline void set_hugetlb_cgroup_rsvd(struct page *page,
 					  struct hugetlb_cgroup *h_cg)
 {
-	return 0;
 }
 
 static inline bool hugetlb_cgroup_disabled(void)
-- 
2.23.0

[PATCH v2 4/5] hugetlb_cgroup: use helper macro NUMA_NO_NODE

[Miaohe Lin]

It's better to use NUMA_NO_NODE instead of magic number -1. Minor
readability improvement.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mina Almasry <almasrymina@google.com>
---
 mm/hugetlb_cgroup.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
index 01a709468937..2affccfe59f1 100644
--- a/mm/hugetlb_cgroup.c
+++ b/mm/hugetlb_cgroup.c
@@ -154,9 +154,9 @@ hugetlb_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
 	 * function.
 	 */
 	for_each_node(node) {
-		/* Set node_to_alloc to -1 for offline nodes. */
+		/* Set node_to_alloc to NUMA_NO_NODE for offline nodes. */
 		int node_to_alloc =
-			node_state(node, N_NORMAL_MEMORY) ? node : -1;
+			node_state(node, N_NORMAL_MEMORY) ? node : NUMA_NO_NODE;
 		h_cgroup->nodeinfo[node] =
 			kzalloc_node(sizeof(struct hugetlb_cgroup_per_node),
 				     GFP_KERNEL, node_to_alloc);
-- 
2.23.0

[PATCH v2 5/5] hugetlb_cgroup: use helper for_each_hstate and hstate_index

[Miaohe Lin]

Use helper for_each_hstate and hstate_index to iterate the hstate and get
the hstate index. Minor readability improvement.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mina Almasry <almasrymina@google.com>
---
 mm/hugetlb_cgroup.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
index 2affccfe59f1..f61d132df52b 100644
--- a/mm/hugetlb_cgroup.c
+++ b/mm/hugetlb_cgroup.c
@@ -75,11 +75,11 @@ parent_hugetlb_cgroup(struct hugetlb_cgroup *h_cg)
 
 static inline bool hugetlb_cgroup_have_usage(struct hugetlb_cgroup *h_cg)
 {
-	int idx;
+	struct hstate *h;
 
-	for (idx = 0; idx < hugetlb_max_hstate; idx++) {
+	for_each_hstate(h) {
 		if (page_counter_read(
-				hugetlb_cgroup_counter_from_cgroup(h_cg, idx)))
+		    hugetlb_cgroup_counter_from_cgroup(h_cg, hstate_index(h))))
 			return true;
 	}
 	return false;
@@ -225,17 +225,14 @@ static void hugetlb_cgroup_css_offline(struct cgroup_subsys_state *css)
 	struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(css);
 	struct hstate *h;
 	struct page *page;
-	int idx;
 
 	do {
-		idx = 0;
 		for_each_hstate(h) {
 			spin_lock_irq(&hugetlb_lock);
 			list_for_each_entry(page, &h->hugepage_activelist, lru)
-				hugetlb_cgroup_move_parent(idx, h_cg, page);
+				hugetlb_cgroup_move_parent(hstate_index(h), h_cg, page);
 
 			spin_unlock_irq(&hugetlb_lock);
-			idx++;
 		}
 		cond_resched();
 	} while (hugetlb_cgroup_have_usage(h_cg));
-- 
2.23.0