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* [PATCH 0/2] remove CONFIG_MOVABLE_NODE
@ 2017-05-29 11:41 ` Michal Hocko
  0 siblings, 0 replies; 14+ messages in thread
From: Michal Hocko @ 2017-05-29 11:41 UTC (permalink / raw)
  To: Andrew Morton
  Cc: linux-mm, Mel Gorman, Vlastimil Babka, Andrea Arcangeli,
	Jerome Glisse, Reza Arbab, Yasuaki Ishimatsu, qiuxishi,
	Kani Toshimitsu, slaoub, Joonsoo Kim, Andi Kleen, David Rientjes,
	Daniel Kiper, Igor Mammedov, Vitaly Kuznetsov, LKML

Hi,
this has been previously posted as an RFC [1]. As it hasn't met any
disagreement, I have integrated the feedback and resending it without
RFC and hope for a soon merging (ideally along with other memory hotplug
pile).

I am continuing to cleanup the memory hotplug code and
CONFIG_MOVABLE_NODE seems dubious at best. The following two patches
simply removes the flag and make it de-facto always enabled.

The current semantic of the config option is twofold 1) it automatically
binds hotplugable nodes to have memory in zone_movable by default when
movable_node is enabled 2) forbids memory hotplug to online all the memory
as movable when !CONFIG_MOVABLE_NODE.

The later restriction is quite dubious because there is no clear cut of
how much normal memory do we need for a reasonable system operation. A
single memory block which is sufficient to allow further movable
onlines is far from sufficient (e.g a node with >2GB and memblocks
128MB will fill up this zone with struct pages leaving nothing for
other allocations). Removing the config option will not only reduce the
configuration space it also removes quite some code.

The semantic of the movable_node command line parameter is preserved.

The first patch removes the restriction mentioned above and the second
one simply removes all the CONFIG_MOVABLE_NODE related stuff. The last
patch moves movable_node flag handling to memory_hotplug proper where
it belongs.

[1] http://lkml.kernel.org/r/20170524122411.25212-1-mhocko@kernel.org

Shortlog
Michal Hocko (3):
      mm, memory_hotplug: drop artificial restriction on online/offline
      mm, memory_hotplug: drop CONFIG_MOVABLE_NODE
      mm, memory_hotplug: move movable_node to the hotplug proper

Diffstat:
 Documentation/admin-guide/kernel-parameters.txt |  7 ++-
 drivers/base/node.c                             |  4 --
 include/linux/memblock.h                        | 25 ----------
 include/linux/memory_hotplug.h                  | 10 ++++
 include/linux/nodemask.h                        |  4 --
 mm/Kconfig                                      | 26 ----------
 mm/memblock.c                                   |  3 --
 mm/memory_hotplug.c                             | 64 ++-----------------------
 mm/page_alloc.c                                 |  2 -
 9 files changed, 19 insertions(+), 126 deletions(-)

^ permalink raw reply	[flat|nested] 14+ messages in thread

* [PATCH 0/2] remove CONFIG_MOVABLE_NODE
@ 2017-05-29 11:41 ` Michal Hocko
  0 siblings, 0 replies; 14+ messages in thread
From: Michal Hocko @ 2017-05-29 11:41 UTC (permalink / raw)
  To: Andrew Morton
  Cc: linux-mm, Mel Gorman, Vlastimil Babka, Andrea Arcangeli,
	Jerome Glisse, Reza Arbab, Yasuaki Ishimatsu, qiuxishi,
	Kani Toshimitsu, slaoub, Joonsoo Kim, Andi Kleen, David Rientjes,
	Daniel Kiper, Igor Mammedov, Vitaly Kuznetsov, LKML

Hi,
this has been previously posted as an RFC [1]. As it hasn't met any
disagreement, I have integrated the feedback and resending it without
RFC and hope for a soon merging (ideally along with other memory hotplug
pile).

I am continuing to cleanup the memory hotplug code and
CONFIG_MOVABLE_NODE seems dubious at best. The following two patches
simply removes the flag and make it de-facto always enabled.

The current semantic of the config option is twofold 1) it automatically
binds hotplugable nodes to have memory in zone_movable by default when
movable_node is enabled 2) forbids memory hotplug to online all the memory
as movable when !CONFIG_MOVABLE_NODE.

The later restriction is quite dubious because there is no clear cut of
how much normal memory do we need for a reasonable system operation. A
single memory block which is sufficient to allow further movable
onlines is far from sufficient (e.g a node with >2GB and memblocks
128MB will fill up this zone with struct pages leaving nothing for
other allocations). Removing the config option will not only reduce the
configuration space it also removes quite some code.

The semantic of the movable_node command line parameter is preserved.

The first patch removes the restriction mentioned above and the second
one simply removes all the CONFIG_MOVABLE_NODE related stuff. The last
patch moves movable_node flag handling to memory_hotplug proper where
it belongs.

[1] http://lkml.kernel.org/r/20170524122411.25212-1-mhocko@kernel.org

Shortlog
Michal Hocko (3):
      mm, memory_hotplug: drop artificial restriction on online/offline
      mm, memory_hotplug: drop CONFIG_MOVABLE_NODE
      mm, memory_hotplug: move movable_node to the hotplug proper

Diffstat:
 Documentation/admin-guide/kernel-parameters.txt |  7 ++-
 drivers/base/node.c                             |  4 --
 include/linux/memblock.h                        | 25 ----------
 include/linux/memory_hotplug.h                  | 10 ++++
 include/linux/nodemask.h                        |  4 --
 mm/Kconfig                                      | 26 ----------
 mm/memblock.c                                   |  3 --
 mm/memory_hotplug.c                             | 64 ++-----------------------
 mm/page_alloc.c                                 |  2 -
 9 files changed, 19 insertions(+), 126 deletions(-)

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
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^ permalink raw reply	[flat|nested] 14+ messages in thread

* [PATCH 1/3] mm, memory_hotplug: drop artificial restriction on online/offline
  2017-05-29 11:41 ` Michal Hocko
@ 2017-05-29 11:41   ` Michal Hocko
  -1 siblings, 0 replies; 14+ messages in thread
From: Michal Hocko @ 2017-05-29 11:41 UTC (permalink / raw)
  To: Andrew Morton
  Cc: linux-mm, Mel Gorman, Vlastimil Babka, Andrea Arcangeli,
	Jerome Glisse, Reza Arbab, Yasuaki Ishimatsu, qiuxishi,
	Kani Toshimitsu, slaoub, Joonsoo Kim, Andi Kleen, David Rientjes,
	Daniel Kiper, Igor Mammedov, Vitaly Kuznetsov, LKML,
	Michal Hocko

From: Michal Hocko <mhocko@suse.com>

74d42d8fe146 ("memory_hotplug: ensure every online node has NORMAL
memory") has introduced a restriction that every numa node has to have
at least some memory in !movable zones before a first movable memory can
be onlined if !CONFIG_MOVABLE_NODE. Likewise_offline_normal checks the
amount of normal memory in !movable zones and it disallows to offline
memory if there is no normal memory left with a justification that
"memory-management acts bad when we have nodes which is online but don't
have any normal memory".

While it is true that not having _any_ memory for kernel allocations on
a NUMA node is far from great and such a node would be quite subotimal
because all kernel allocations will have to fallback to another NUMA
node but there is no reason to disallow such a configuration in
principle.

Besides that there is not really a big difference to have one memblock
for ZONE_NORMAL available or none. With 128MB size memblocks the system
might trash on the kernel allocations requests anyway. It is really
hard to draw a line on how much normal memory is really sufficient so
we have to rely on administrator to configure system sanely therefore
drop the artificial restriction and remove can_offline_normal and
can_online_high_movable altogether.

Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Signed-off-by: Michal Hocko <mhocko@suse.com>
---
 mm/memory_hotplug.c | 58 -----------------------------------------------------
 1 file changed, 58 deletions(-)

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 599c675ad538..10052c2fd400 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -763,23 +763,6 @@ static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
 	return 0;
 }
 
-#ifdef CONFIG_MOVABLE_NODE
-/*
- * When CONFIG_MOVABLE_NODE, we permit onlining of a node which doesn't have
- * normal memory.
- */
-static bool can_online_high_movable(int nid)
-{
-	return true;
-}
-#else /* CONFIG_MOVABLE_NODE */
-/* ensure every online node has NORMAL memory */
-static bool can_online_high_movable(int nid)
-{
-	return node_state(nid, N_NORMAL_MEMORY);
-}
-#endif /* CONFIG_MOVABLE_NODE */
-
 /* check which state of node_states will be changed when online memory */
 static void node_states_check_changes_online(unsigned long nr_pages,
 	struct zone *zone, struct memory_notify *arg)
@@ -979,9 +962,6 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ
 	if (!allow_online_pfn_range(nid, pfn, nr_pages, online_type))
 		return -EINVAL;
 
-	if (online_type == MMOP_ONLINE_MOVABLE && !can_online_high_movable(nid))
-		return -EINVAL;
-
 	/* associate pfn range with the zone */
 	zone = move_pfn_range(online_type, nid, pfn, nr_pages);
 
@@ -1579,41 +1559,6 @@ check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
 	return offlined;
 }
 
-#ifdef CONFIG_MOVABLE_NODE
-/*
- * When CONFIG_MOVABLE_NODE, we permit offlining of a node which doesn't have
- * normal memory.
- */
-static bool can_offline_normal(struct zone *zone, unsigned long nr_pages)
-{
-	return true;
-}
-#else /* CONFIG_MOVABLE_NODE */
-/* ensure the node has NORMAL memory if it is still online */
-static bool can_offline_normal(struct zone *zone, unsigned long nr_pages)
-{
-	struct pglist_data *pgdat = zone->zone_pgdat;
-	unsigned long present_pages = 0;
-	enum zone_type zt;
-
-	for (zt = 0; zt <= ZONE_NORMAL; zt++)
-		present_pages += pgdat->node_zones[zt].present_pages;
-
-	if (present_pages > nr_pages)
-		return true;
-
-	present_pages = 0;
-	for (; zt <= ZONE_MOVABLE; zt++)
-		present_pages += pgdat->node_zones[zt].present_pages;
-
-	/*
-	 * we can't offline the last normal memory until all
-	 * higher memory is offlined.
-	 */
-	return present_pages == 0;
-}
-#endif /* CONFIG_MOVABLE_NODE */
-
 static int __init cmdline_parse_movable_node(char *p)
 {
 #ifdef CONFIG_MOVABLE_NODE
@@ -1741,9 +1686,6 @@ static int __ref __offline_pages(unsigned long start_pfn,
 	node = zone_to_nid(zone);
 	nr_pages = end_pfn - start_pfn;
 
-	if (zone_idx(zone) <= ZONE_NORMAL && !can_offline_normal(zone, nr_pages))
-		return -EINVAL;
-
 	/* set above range as isolated */
 	ret = start_isolate_page_range(start_pfn, end_pfn,
 				       MIGRATE_MOVABLE, true);
-- 
2.11.0

^ permalink raw reply	[flat|nested] 14+ messages in thread

* [PATCH 1/3] mm, memory_hotplug: drop artificial restriction on online/offline
@ 2017-05-29 11:41   ` Michal Hocko
  0 siblings, 0 replies; 14+ messages in thread
From: Michal Hocko @ 2017-05-29 11:41 UTC (permalink / raw)
  To: Andrew Morton
  Cc: linux-mm, Mel Gorman, Vlastimil Babka, Andrea Arcangeli,
	Jerome Glisse, Reza Arbab, Yasuaki Ishimatsu, qiuxishi,
	Kani Toshimitsu, slaoub, Joonsoo Kim, Andi Kleen, David Rientjes,
	Daniel Kiper, Igor Mammedov, Vitaly Kuznetsov, LKML,
	Michal Hocko

From: Michal Hocko <mhocko@suse.com>

74d42d8fe146 ("memory_hotplug: ensure every online node has NORMAL
memory") has introduced a restriction that every numa node has to have
at least some memory in !movable zones before a first movable memory can
be onlined if !CONFIG_MOVABLE_NODE. Likewise_offline_normal checks the
amount of normal memory in !movable zones and it disallows to offline
memory if there is no normal memory left with a justification that
"memory-management acts bad when we have nodes which is online but don't
have any normal memory".

While it is true that not having _any_ memory for kernel allocations on
a NUMA node is far from great and such a node would be quite subotimal
because all kernel allocations will have to fallback to another NUMA
node but there is no reason to disallow such a configuration in
principle.

Besides that there is not really a big difference to have one memblock
for ZONE_NORMAL available or none. With 128MB size memblocks the system
might trash on the kernel allocations requests anyway. It is really
hard to draw a line on how much normal memory is really sufficient so
we have to rely on administrator to configure system sanely therefore
drop the artificial restriction and remove can_offline_normal and
can_online_high_movable altogether.

Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Signed-off-by: Michal Hocko <mhocko@suse.com>
---
 mm/memory_hotplug.c | 58 -----------------------------------------------------
 1 file changed, 58 deletions(-)

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 599c675ad538..10052c2fd400 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -763,23 +763,6 @@ static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
 	return 0;
 }
 
-#ifdef CONFIG_MOVABLE_NODE
-/*
- * When CONFIG_MOVABLE_NODE, we permit onlining of a node which doesn't have
- * normal memory.
- */
-static bool can_online_high_movable(int nid)
-{
-	return true;
-}
-#else /* CONFIG_MOVABLE_NODE */
-/* ensure every online node has NORMAL memory */
-static bool can_online_high_movable(int nid)
-{
-	return node_state(nid, N_NORMAL_MEMORY);
-}
-#endif /* CONFIG_MOVABLE_NODE */
-
 /* check which state of node_states will be changed when online memory */
 static void node_states_check_changes_online(unsigned long nr_pages,
 	struct zone *zone, struct memory_notify *arg)
@@ -979,9 +962,6 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ
 	if (!allow_online_pfn_range(nid, pfn, nr_pages, online_type))
 		return -EINVAL;
 
-	if (online_type == MMOP_ONLINE_MOVABLE && !can_online_high_movable(nid))
-		return -EINVAL;
-
 	/* associate pfn range with the zone */
 	zone = move_pfn_range(online_type, nid, pfn, nr_pages);
 
@@ -1579,41 +1559,6 @@ check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
 	return offlined;
 }
 
-#ifdef CONFIG_MOVABLE_NODE
-/*
- * When CONFIG_MOVABLE_NODE, we permit offlining of a node which doesn't have
- * normal memory.
- */
-static bool can_offline_normal(struct zone *zone, unsigned long nr_pages)
-{
-	return true;
-}
-#else /* CONFIG_MOVABLE_NODE */
-/* ensure the node has NORMAL memory if it is still online */
-static bool can_offline_normal(struct zone *zone, unsigned long nr_pages)
-{
-	struct pglist_data *pgdat = zone->zone_pgdat;
-	unsigned long present_pages = 0;
-	enum zone_type zt;
-
-	for (zt = 0; zt <= ZONE_NORMAL; zt++)
-		present_pages += pgdat->node_zones[zt].present_pages;
-
-	if (present_pages > nr_pages)
-		return true;
-
-	present_pages = 0;
-	for (; zt <= ZONE_MOVABLE; zt++)
-		present_pages += pgdat->node_zones[zt].present_pages;
-
-	/*
-	 * we can't offline the last normal memory until all
-	 * higher memory is offlined.
-	 */
-	return present_pages == 0;
-}
-#endif /* CONFIG_MOVABLE_NODE */
-
 static int __init cmdline_parse_movable_node(char *p)
 {
 #ifdef CONFIG_MOVABLE_NODE
@@ -1741,9 +1686,6 @@ static int __ref __offline_pages(unsigned long start_pfn,
 	node = zone_to_nid(zone);
 	nr_pages = end_pfn - start_pfn;
 
-	if (zone_idx(zone) <= ZONE_NORMAL && !can_offline_normal(zone, nr_pages))
-		return -EINVAL;
-
 	/* set above range as isolated */
 	ret = start_isolate_page_range(start_pfn, end_pfn,
 				       MIGRATE_MOVABLE, true);
-- 
2.11.0

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
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^ permalink raw reply	[flat|nested] 14+ messages in thread

* [PATCH 2/3] mm, memory_hotplug: drop CONFIG_MOVABLE_NODE
  2017-05-29 11:41 ` Michal Hocko
@ 2017-05-29 11:41   ` Michal Hocko
  -1 siblings, 0 replies; 14+ messages in thread
From: Michal Hocko @ 2017-05-29 11:41 UTC (permalink / raw)
  To: Andrew Morton
  Cc: linux-mm, Mel Gorman, Vlastimil Babka, Andrea Arcangeli,
	Jerome Glisse, Reza Arbab, Yasuaki Ishimatsu, qiuxishi,
	Kani Toshimitsu, slaoub, Joonsoo Kim, Andi Kleen, David Rientjes,
	Daniel Kiper, Igor Mammedov, Vitaly Kuznetsov, LKML,
	Michal Hocko

From: Michal Hocko <mhocko@suse.com>

20b2f52b73fe ("numa: add CONFIG_MOVABLE_NODE for movable-dedicated
node") has introduced CONFIG_MOVABLE_NODE without a good explanation on
why it is actually useful. It makes a lot of sense to make movable node
semantic opt in but we already have that because the feature has to be
explicitly enabled on the kernel command line. A config option on top
only makes the configuration space larger without a good reason. It also
adds an additional ifdefery that pollutes the code. Just drop the config
option and make it de-facto always enabled. This shouldn't introduce any
change to the semantic.

Acked-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Signed-off-by: Michal Hocko <mhocko@suse.com>
---
 Documentation/admin-guide/kernel-parameters.txt |  7 +++++--
 drivers/base/node.c                             |  4 ----
 include/linux/memblock.h                        | 18 -----------------
 include/linux/nodemask.h                        |  4 ----
 mm/Kconfig                                      | 26 -------------------------
 mm/memblock.c                                   |  2 --
 mm/memory_hotplug.c                             |  4 ----
 mm/page_alloc.c                                 |  2 --
 8 files changed, 5 insertions(+), 62 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index facc20a3f962..64aed7386fe4 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2246,8 +2246,11 @@
 			that the amount of memory usable for all allocations
 			is not too small.
 
-	movable_node	[KNL] Boot-time switch to enable the effects
-			of CONFIG_MOVABLE_NODE=y. See mm/Kconfig for details.
+	movable_node	[KNL] Boot-time switch to make hotplugable memory
+			NUMA nodes to be movable. This means that the memory
+			of such nodes will be usable only for movable
+			allocations which rules out almost all kernel
+			allocations. Use with caution!
 
 	MTD_Partition=	[MTD]
 			Format: <name>,<region-number>,<size>,<offset>
diff --git a/drivers/base/node.c b/drivers/base/node.c
index dff5b53f7905..26f4b9c02f2c 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -639,9 +639,7 @@ static struct node_attr node_state_attr[] = {
 #ifdef CONFIG_HIGHMEM
 	[N_HIGH_MEMORY] = _NODE_ATTR(has_high_memory, N_HIGH_MEMORY),
 #endif
-#ifdef CONFIG_MOVABLE_NODE
 	[N_MEMORY] = _NODE_ATTR(has_memory, N_MEMORY),
-#endif
 	[N_CPU] = _NODE_ATTR(has_cpu, N_CPU),
 };
 
@@ -652,9 +650,7 @@ static struct attribute *node_state_attrs[] = {
 #ifdef CONFIG_HIGHMEM
 	&node_state_attr[N_HIGH_MEMORY].attr.attr,
 #endif
-#ifdef CONFIG_MOVABLE_NODE
 	&node_state_attr[N_MEMORY].attr.attr,
-#endif
 	&node_state_attr[N_CPU].attr.attr,
 	NULL
 };
diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index bdfc65af4152..9622fb8c101b 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -57,10 +57,8 @@ struct memblock {
 
 extern struct memblock memblock;
 extern int memblock_debug;
-#ifdef CONFIG_MOVABLE_NODE
 /* If movable_node boot option specified */
 extern bool movable_node_enabled;
-#endif /* CONFIG_MOVABLE_NODE */
 
 #ifdef CONFIG_ARCH_DISCARD_MEMBLOCK
 #define __init_memblock __meminit
@@ -168,7 +166,6 @@ void __next_reserved_mem_region(u64 *idx, phys_addr_t *out_start,
 	     i != (u64)ULLONG_MAX;					\
 	     __next_reserved_mem_region(&i, p_start, p_end))
 
-#ifdef CONFIG_MOVABLE_NODE
 static inline bool memblock_is_hotpluggable(struct memblock_region *m)
 {
 	return m->flags & MEMBLOCK_HOTPLUG;
@@ -178,16 +175,6 @@ static inline bool __init_memblock movable_node_is_enabled(void)
 {
 	return movable_node_enabled;
 }
-#else
-static inline bool memblock_is_hotpluggable(struct memblock_region *m)
-{
-	return false;
-}
-static inline bool movable_node_is_enabled(void)
-{
-	return false;
-}
-#endif
 
 static inline bool memblock_is_mirror(struct memblock_region *m)
 {
@@ -295,7 +282,6 @@ phys_addr_t memblock_alloc_try_nid(phys_addr_t size, phys_addr_t align, int nid)
 
 phys_addr_t memblock_alloc(phys_addr_t size, phys_addr_t align);
 
-#ifdef CONFIG_MOVABLE_NODE
 /*
  * Set the allocation direction to bottom-up or top-down.
  */
@@ -313,10 +299,6 @@ static inline bool memblock_bottom_up(void)
 {
 	return memblock.bottom_up;
 }
-#else
-static inline void __init memblock_set_bottom_up(bool enable) {}
-static inline bool memblock_bottom_up(void) { return false; }
-#endif
 
 /* Flags for memblock_alloc_base() amd __memblock_alloc_base() */
 #define MEMBLOCK_ALLOC_ANYWHERE	(~(phys_addr_t)0)
diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
index f746e44d4046..cf0b91c3ec12 100644
--- a/include/linux/nodemask.h
+++ b/include/linux/nodemask.h
@@ -387,11 +387,7 @@ enum node_states {
 #else
 	N_HIGH_MEMORY = N_NORMAL_MEMORY,
 #endif
-#ifdef CONFIG_MOVABLE_NODE
 	N_MEMORY,		/* The node has memory(regular, high, movable) */
-#else
-	N_MEMORY = N_HIGH_MEMORY,
-#endif
 	N_CPU,		/* The node has one or more cpus */
 	NR_NODE_STATES
 };
diff --git a/mm/Kconfig b/mm/Kconfig
index 0354a4be5a55..99645f42dc62 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -149,32 +149,6 @@ config NO_BOOTMEM
 config MEMORY_ISOLATION
 	bool
 
-config MOVABLE_NODE
-	bool "Enable to assign a node which has only movable memory"
-	depends on HAVE_MEMBLOCK
-	depends on NO_BOOTMEM
-	depends on X86_64 || OF_EARLY_FLATTREE || MEMORY_HOTPLUG
-	depends on NUMA
-	default n
-	help
-	  Allow a node to have only movable memory.  Pages used by the kernel,
-	  such as direct mapping pages cannot be migrated.  So the corresponding
-	  memory device cannot be hotplugged.  This option allows the following
-	  two things:
-	  - When the system is booting, node full of hotpluggable memory can
-	  be arranged to have only movable memory so that the whole node can
-	  be hot-removed. (need movable_node boot option specified).
-	  - After the system is up, the option allows users to online all the
-	  memory of a node as movable memory so that the whole node can be
-	  hot-removed.
-
-	  Users who don't use the memory hotplug feature are fine with this
-	  option on since they don't specify movable_node boot option or they
-	  don't online memory as movable.
-
-	  Say Y here if you want to hotplug a whole node.
-	  Say N here if you want kernel to use memory on all nodes evenly.
-
 #
 # Only be set on architectures that have completely implemented memory hotplug
 # feature. If you are not sure, don't touch it.
diff --git a/mm/memblock.c b/mm/memblock.c
index 696f06d17c4e..4895f5a6cf7e 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -54,9 +54,7 @@ struct memblock memblock __initdata_memblock = {
 };
 
 int memblock_debug __initdata_memblock;
-#ifdef CONFIG_MOVABLE_NODE
 bool movable_node_enabled __initdata_memblock = false;
-#endif
 static bool system_has_some_mirror __initdata_memblock = false;
 static int memblock_can_resize __initdata_memblock;
 static int memblock_memory_in_slab __initdata_memblock = 0;
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 10052c2fd400..2a14f8c18a22 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1561,11 +1561,7 @@ check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
 
 static int __init cmdline_parse_movable_node(char *p)
 {
-#ifdef CONFIG_MOVABLE_NODE
 	movable_node_enabled = true;
-#else
-	pr_warn("movable_node option not supported\n");
-#endif
 	return 0;
 }
 early_param("movable_node", cmdline_parse_movable_node);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index a26e19c3e1ff..02f5757bf253 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -112,9 +112,7 @@ nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
 #ifdef CONFIG_HIGHMEM
 	[N_HIGH_MEMORY] = { { [0] = 1UL } },
 #endif
-#ifdef CONFIG_MOVABLE_NODE
 	[N_MEMORY] = { { [0] = 1UL } },
-#endif
 	[N_CPU] = { { [0] = 1UL } },
 #endif	/* NUMA */
 };
-- 
2.11.0

^ permalink raw reply	[flat|nested] 14+ messages in thread

* [PATCH 2/3] mm, memory_hotplug: drop CONFIG_MOVABLE_NODE
@ 2017-05-29 11:41   ` Michal Hocko
  0 siblings, 0 replies; 14+ messages in thread
From: Michal Hocko @ 2017-05-29 11:41 UTC (permalink / raw)
  To: Andrew Morton
  Cc: linux-mm, Mel Gorman, Vlastimil Babka, Andrea Arcangeli,
	Jerome Glisse, Reza Arbab, Yasuaki Ishimatsu, qiuxishi,
	Kani Toshimitsu, slaoub, Joonsoo Kim, Andi Kleen, David Rientjes,
	Daniel Kiper, Igor Mammedov, Vitaly Kuznetsov, LKML,
	Michal Hocko

From: Michal Hocko <mhocko@suse.com>

20b2f52b73fe ("numa: add CONFIG_MOVABLE_NODE for movable-dedicated
node") has introduced CONFIG_MOVABLE_NODE without a good explanation on
why it is actually useful. It makes a lot of sense to make movable node
semantic opt in but we already have that because the feature has to be
explicitly enabled on the kernel command line. A config option on top
only makes the configuration space larger without a good reason. It also
adds an additional ifdefery that pollutes the code. Just drop the config
option and make it de-facto always enabled. This shouldn't introduce any
change to the semantic.

Acked-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Signed-off-by: Michal Hocko <mhocko@suse.com>
---
 Documentation/admin-guide/kernel-parameters.txt |  7 +++++--
 drivers/base/node.c                             |  4 ----
 include/linux/memblock.h                        | 18 -----------------
 include/linux/nodemask.h                        |  4 ----
 mm/Kconfig                                      | 26 -------------------------
 mm/memblock.c                                   |  2 --
 mm/memory_hotplug.c                             |  4 ----
 mm/page_alloc.c                                 |  2 --
 8 files changed, 5 insertions(+), 62 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index facc20a3f962..64aed7386fe4 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2246,8 +2246,11 @@
 			that the amount of memory usable for all allocations
 			is not too small.
 
-	movable_node	[KNL] Boot-time switch to enable the effects
-			of CONFIG_MOVABLE_NODE=y. See mm/Kconfig for details.
+	movable_node	[KNL] Boot-time switch to make hotplugable memory
+			NUMA nodes to be movable. This means that the memory
+			of such nodes will be usable only for movable
+			allocations which rules out almost all kernel
+			allocations. Use with caution!
 
 	MTD_Partition=	[MTD]
 			Format: <name>,<region-number>,<size>,<offset>
diff --git a/drivers/base/node.c b/drivers/base/node.c
index dff5b53f7905..26f4b9c02f2c 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -639,9 +639,7 @@ static struct node_attr node_state_attr[] = {
 #ifdef CONFIG_HIGHMEM
 	[N_HIGH_MEMORY] = _NODE_ATTR(has_high_memory, N_HIGH_MEMORY),
 #endif
-#ifdef CONFIG_MOVABLE_NODE
 	[N_MEMORY] = _NODE_ATTR(has_memory, N_MEMORY),
-#endif
 	[N_CPU] = _NODE_ATTR(has_cpu, N_CPU),
 };
 
@@ -652,9 +650,7 @@ static struct attribute *node_state_attrs[] = {
 #ifdef CONFIG_HIGHMEM
 	&node_state_attr[N_HIGH_MEMORY].attr.attr,
 #endif
-#ifdef CONFIG_MOVABLE_NODE
 	&node_state_attr[N_MEMORY].attr.attr,
-#endif
 	&node_state_attr[N_CPU].attr.attr,
 	NULL
 };
diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index bdfc65af4152..9622fb8c101b 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -57,10 +57,8 @@ struct memblock {
 
 extern struct memblock memblock;
 extern int memblock_debug;
-#ifdef CONFIG_MOVABLE_NODE
 /* If movable_node boot option specified */
 extern bool movable_node_enabled;
-#endif /* CONFIG_MOVABLE_NODE */
 
 #ifdef CONFIG_ARCH_DISCARD_MEMBLOCK
 #define __init_memblock __meminit
@@ -168,7 +166,6 @@ void __next_reserved_mem_region(u64 *idx, phys_addr_t *out_start,
 	     i != (u64)ULLONG_MAX;					\
 	     __next_reserved_mem_region(&i, p_start, p_end))
 
-#ifdef CONFIG_MOVABLE_NODE
 static inline bool memblock_is_hotpluggable(struct memblock_region *m)
 {
 	return m->flags & MEMBLOCK_HOTPLUG;
@@ -178,16 +175,6 @@ static inline bool __init_memblock movable_node_is_enabled(void)
 {
 	return movable_node_enabled;
 }
-#else
-static inline bool memblock_is_hotpluggable(struct memblock_region *m)
-{
-	return false;
-}
-static inline bool movable_node_is_enabled(void)
-{
-	return false;
-}
-#endif
 
 static inline bool memblock_is_mirror(struct memblock_region *m)
 {
@@ -295,7 +282,6 @@ phys_addr_t memblock_alloc_try_nid(phys_addr_t size, phys_addr_t align, int nid)
 
 phys_addr_t memblock_alloc(phys_addr_t size, phys_addr_t align);
 
-#ifdef CONFIG_MOVABLE_NODE
 /*
  * Set the allocation direction to bottom-up or top-down.
  */
@@ -313,10 +299,6 @@ static inline bool memblock_bottom_up(void)
 {
 	return memblock.bottom_up;
 }
-#else
-static inline void __init memblock_set_bottom_up(bool enable) {}
-static inline bool memblock_bottom_up(void) { return false; }
-#endif
 
 /* Flags for memblock_alloc_base() amd __memblock_alloc_base() */
 #define MEMBLOCK_ALLOC_ANYWHERE	(~(phys_addr_t)0)
diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
index f746e44d4046..cf0b91c3ec12 100644
--- a/include/linux/nodemask.h
+++ b/include/linux/nodemask.h
@@ -387,11 +387,7 @@ enum node_states {
 #else
 	N_HIGH_MEMORY = N_NORMAL_MEMORY,
 #endif
-#ifdef CONFIG_MOVABLE_NODE
 	N_MEMORY,		/* The node has memory(regular, high, movable) */
-#else
-	N_MEMORY = N_HIGH_MEMORY,
-#endif
 	N_CPU,		/* The node has one or more cpus */
 	NR_NODE_STATES
 };
diff --git a/mm/Kconfig b/mm/Kconfig
index 0354a4be5a55..99645f42dc62 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -149,32 +149,6 @@ config NO_BOOTMEM
 config MEMORY_ISOLATION
 	bool
 
-config MOVABLE_NODE
-	bool "Enable to assign a node which has only movable memory"
-	depends on HAVE_MEMBLOCK
-	depends on NO_BOOTMEM
-	depends on X86_64 || OF_EARLY_FLATTREE || MEMORY_HOTPLUG
-	depends on NUMA
-	default n
-	help
-	  Allow a node to have only movable memory.  Pages used by the kernel,
-	  such as direct mapping pages cannot be migrated.  So the corresponding
-	  memory device cannot be hotplugged.  This option allows the following
-	  two things:
-	  - When the system is booting, node full of hotpluggable memory can
-	  be arranged to have only movable memory so that the whole node can
-	  be hot-removed. (need movable_node boot option specified).
-	  - After the system is up, the option allows users to online all the
-	  memory of a node as movable memory so that the whole node can be
-	  hot-removed.
-
-	  Users who don't use the memory hotplug feature are fine with this
-	  option on since they don't specify movable_node boot option or they
-	  don't online memory as movable.
-
-	  Say Y here if you want to hotplug a whole node.
-	  Say N here if you want kernel to use memory on all nodes evenly.
-
 #
 # Only be set on architectures that have completely implemented memory hotplug
 # feature. If you are not sure, don't touch it.
diff --git a/mm/memblock.c b/mm/memblock.c
index 696f06d17c4e..4895f5a6cf7e 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -54,9 +54,7 @@ struct memblock memblock __initdata_memblock = {
 };
 
 int memblock_debug __initdata_memblock;
-#ifdef CONFIG_MOVABLE_NODE
 bool movable_node_enabled __initdata_memblock = false;
-#endif
 static bool system_has_some_mirror __initdata_memblock = false;
 static int memblock_can_resize __initdata_memblock;
 static int memblock_memory_in_slab __initdata_memblock = 0;
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 10052c2fd400..2a14f8c18a22 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1561,11 +1561,7 @@ check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
 
 static int __init cmdline_parse_movable_node(char *p)
 {
-#ifdef CONFIG_MOVABLE_NODE
 	movable_node_enabled = true;
-#else
-	pr_warn("movable_node option not supported\n");
-#endif
 	return 0;
 }
 early_param("movable_node", cmdline_parse_movable_node);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index a26e19c3e1ff..02f5757bf253 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -112,9 +112,7 @@ nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
 #ifdef CONFIG_HIGHMEM
 	[N_HIGH_MEMORY] = { { [0] = 1UL } },
 #endif
-#ifdef CONFIG_MOVABLE_NODE
 	[N_MEMORY] = { { [0] = 1UL } },
-#endif
 	[N_CPU] = { { [0] = 1UL } },
 #endif	/* NUMA */
 };
-- 
2.11.0

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
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^ permalink raw reply	[flat|nested] 14+ messages in thread

* [PATCH 3/3] mm, memory_hotplug: move movable_node to the hotplug proper
  2017-05-29 11:41 ` Michal Hocko
@ 2017-05-29 11:41   ` Michal Hocko
  -1 siblings, 0 replies; 14+ messages in thread
From: Michal Hocko @ 2017-05-29 11:41 UTC (permalink / raw)
  To: Andrew Morton
  Cc: linux-mm, Mel Gorman, Vlastimil Babka, Andrea Arcangeli,
	Jerome Glisse, Reza Arbab, Yasuaki Ishimatsu, qiuxishi,
	Kani Toshimitsu, slaoub, Joonsoo Kim, Andi Kleen, David Rientjes,
	Daniel Kiper, Igor Mammedov, Vitaly Kuznetsov, LKML,
	Michal Hocko

From: Michal Hocko <mhocko@suse.com>

movable_node_is_enabled is defined in memblock proper while it
is initialized from the memory hotplug proper. This is quite messy
and it makes a dependency between the two so move movable_node along
with the helper functions to memory_hotplug.

To make it more entertaining the kernel parameter is ignored unless
CONFIG_HAVE_MEMBLOCK_NODE_MAP=y because we do not have the node
information for each memblock otherwise. So let's warn when the option
is disabled.

Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Michal Hocko <mhocko@suse.com>
---
 include/linux/memblock.h       |  7 -------
 include/linux/memory_hotplug.h | 10 ++++++++++
 mm/memblock.c                  |  1 -
 mm/memory_hotplug.c            |  6 ++++++
 4 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 9622fb8c101b..071692894254 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -57,8 +57,6 @@ struct memblock {
 
 extern struct memblock memblock;
 extern int memblock_debug;
-/* If movable_node boot option specified */
-extern bool movable_node_enabled;
 
 #ifdef CONFIG_ARCH_DISCARD_MEMBLOCK
 #define __init_memblock __meminit
@@ -171,11 +169,6 @@ static inline bool memblock_is_hotpluggable(struct memblock_region *m)
 	return m->flags & MEMBLOCK_HOTPLUG;
 }
 
-static inline bool __init_memblock movable_node_is_enabled(void)
-{
-	return movable_node_enabled;
-}
-
 static inline bool memblock_is_mirror(struct memblock_region *m)
 {
 	return m->flags & MEMBLOCK_MIRROR;
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 9e0249d0f5e4..d6e5e63b31d5 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -115,6 +115,12 @@ extern void __online_page_free(struct page *page);
 extern int try_online_node(int nid);
 
 extern bool memhp_auto_online;
+/* If movable_node boot option specified */
+extern bool movable_node_enabled;
+static inline bool movable_node_is_enabled(void)
+{
+	return movable_node_enabled;
+}
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
 extern bool is_pageblock_removable_nolock(struct page *page);
@@ -266,6 +272,10 @@ static inline void put_online_mems(void) {}
 static inline void mem_hotplug_begin(void) {}
 static inline void mem_hotplug_done(void) {}
 
+static inline bool movable_node_is_enabled(void)
+{
+	return false;
+}
 #endif /* ! CONFIG_MEMORY_HOTPLUG */
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
diff --git a/mm/memblock.c b/mm/memblock.c
index 4895f5a6cf7e..8c52fb11510c 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -54,7 +54,6 @@ struct memblock memblock __initdata_memblock = {
 };
 
 int memblock_debug __initdata_memblock;
-bool movable_node_enabled __initdata_memblock = false;
 static bool system_has_some_mirror __initdata_memblock = false;
 static int memblock_can_resize __initdata_memblock;
 static int memblock_memory_in_slab __initdata_memblock = 0;
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 2a14f8c18a22..1a148b35e8a3 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -79,6 +79,8 @@ static struct {
 #define memhp_lock_acquire()      lock_map_acquire(&mem_hotplug.dep_map)
 #define memhp_lock_release()      lock_map_release(&mem_hotplug.dep_map)
 
+bool movable_node_enabled = false;
+
 #ifndef CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE
 bool memhp_auto_online;
 #else
@@ -1561,7 +1563,11 @@ check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
 
 static int __init cmdline_parse_movable_node(char *p)
 {
+#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
 	movable_node_enabled = true;
+#else
+	pr_warn("movable_node parameter depends on CONFIG_HAVE_MEMBLOCK_NODE_MAP to work properly\n");
+#endif
 	return 0;
 }
 early_param("movable_node", cmdline_parse_movable_node);
-- 
2.11.0

^ permalink raw reply	[flat|nested] 14+ messages in thread

* [PATCH 3/3] mm, memory_hotplug: move movable_node to the hotplug proper
@ 2017-05-29 11:41   ` Michal Hocko
  0 siblings, 0 replies; 14+ messages in thread
From: Michal Hocko @ 2017-05-29 11:41 UTC (permalink / raw)
  To: Andrew Morton
  Cc: linux-mm, Mel Gorman, Vlastimil Babka, Andrea Arcangeli,
	Jerome Glisse, Reza Arbab, Yasuaki Ishimatsu, qiuxishi,
	Kani Toshimitsu, slaoub, Joonsoo Kim, Andi Kleen, David Rientjes,
	Daniel Kiper, Igor Mammedov, Vitaly Kuznetsov, LKML,
	Michal Hocko

From: Michal Hocko <mhocko@suse.com>

movable_node_is_enabled is defined in memblock proper while it
is initialized from the memory hotplug proper. This is quite messy
and it makes a dependency between the two so move movable_node along
with the helper functions to memory_hotplug.

To make it more entertaining the kernel parameter is ignored unless
CONFIG_HAVE_MEMBLOCK_NODE_MAP=y because we do not have the node
information for each memblock otherwise. So let's warn when the option
is disabled.

Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Michal Hocko <mhocko@suse.com>
---
 include/linux/memblock.h       |  7 -------
 include/linux/memory_hotplug.h | 10 ++++++++++
 mm/memblock.c                  |  1 -
 mm/memory_hotplug.c            |  6 ++++++
 4 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 9622fb8c101b..071692894254 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -57,8 +57,6 @@ struct memblock {
 
 extern struct memblock memblock;
 extern int memblock_debug;
-/* If movable_node boot option specified */
-extern bool movable_node_enabled;
 
 #ifdef CONFIG_ARCH_DISCARD_MEMBLOCK
 #define __init_memblock __meminit
@@ -171,11 +169,6 @@ static inline bool memblock_is_hotpluggable(struct memblock_region *m)
 	return m->flags & MEMBLOCK_HOTPLUG;
 }
 
-static inline bool __init_memblock movable_node_is_enabled(void)
-{
-	return movable_node_enabled;
-}
-
 static inline bool memblock_is_mirror(struct memblock_region *m)
 {
 	return m->flags & MEMBLOCK_MIRROR;
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 9e0249d0f5e4..d6e5e63b31d5 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -115,6 +115,12 @@ extern void __online_page_free(struct page *page);
 extern int try_online_node(int nid);
 
 extern bool memhp_auto_online;
+/* If movable_node boot option specified */
+extern bool movable_node_enabled;
+static inline bool movable_node_is_enabled(void)
+{
+	return movable_node_enabled;
+}
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
 extern bool is_pageblock_removable_nolock(struct page *page);
@@ -266,6 +272,10 @@ static inline void put_online_mems(void) {}
 static inline void mem_hotplug_begin(void) {}
 static inline void mem_hotplug_done(void) {}
 
+static inline bool movable_node_is_enabled(void)
+{
+	return false;
+}
 #endif /* ! CONFIG_MEMORY_HOTPLUG */
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
diff --git a/mm/memblock.c b/mm/memblock.c
index 4895f5a6cf7e..8c52fb11510c 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -54,7 +54,6 @@ struct memblock memblock __initdata_memblock = {
 };
 
 int memblock_debug __initdata_memblock;
-bool movable_node_enabled __initdata_memblock = false;
 static bool system_has_some_mirror __initdata_memblock = false;
 static int memblock_can_resize __initdata_memblock;
 static int memblock_memory_in_slab __initdata_memblock = 0;
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 2a14f8c18a22..1a148b35e8a3 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -79,6 +79,8 @@ static struct {
 #define memhp_lock_acquire()      lock_map_acquire(&mem_hotplug.dep_map)
 #define memhp_lock_release()      lock_map_release(&mem_hotplug.dep_map)
 
+bool movable_node_enabled = false;
+
 #ifndef CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE
 bool memhp_auto_online;
 #else
@@ -1561,7 +1563,11 @@ check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
 
 static int __init cmdline_parse_movable_node(char *p)
 {
+#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
 	movable_node_enabled = true;
+#else
+	pr_warn("movable_node parameter depends on CONFIG_HAVE_MEMBLOCK_NODE_MAP to work properly\n");
+#endif
 	return 0;
 }
 early_param("movable_node", cmdline_parse_movable_node);
-- 
2.11.0

--
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	[flat|nested] 14+ messages in thread

* Re: [PATCH 2/3] mm, memory_hotplug: drop CONFIG_MOVABLE_NODE
  2017-05-29 11:41   ` Michal Hocko
@ 2017-05-29 12:08     ` Vlastimil Babka
  -1 siblings, 0 replies; 14+ messages in thread
From: Vlastimil Babka @ 2017-05-29 12:08 UTC (permalink / raw)
  To: Michal Hocko, Andrew Morton
  Cc: linux-mm, Mel Gorman, Andrea Arcangeli, Jerome Glisse,
	Reza Arbab, Yasuaki Ishimatsu, qiuxishi, Kani Toshimitsu, slaoub,
	Joonsoo Kim, Andi Kleen, David Rientjes, Daniel Kiper,
	Igor Mammedov, Vitaly Kuznetsov, LKML, Michal Hocko

On 05/29/2017 01:41 PM, Michal Hocko wrote:
> From: Michal Hocko <mhocko@suse.com>
> 
> 20b2f52b73fe ("numa: add CONFIG_MOVABLE_NODE for movable-dedicated
> node") has introduced CONFIG_MOVABLE_NODE without a good explanation on
> why it is actually useful. It makes a lot of sense to make movable node
> semantic opt in but we already have that because the feature has to be
> explicitly enabled on the kernel command line. A config option on top
> only makes the configuration space larger without a good reason. It also
> adds an additional ifdefery that pollutes the code. Just drop the config
> option and make it de-facto always enabled. This shouldn't introduce any
> change to the semantic.
> 
> Acked-by: Reza Arbab <arbab@linux.vnet.ibm.com>
> Signed-off-by: Michal Hocko <mhocko@suse.com>

Acked-by: Vlastimil Babka <vbabka@suse.cz>

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH 2/3] mm, memory_hotplug: drop CONFIG_MOVABLE_NODE
@ 2017-05-29 12:08     ` Vlastimil Babka
  0 siblings, 0 replies; 14+ messages in thread
From: Vlastimil Babka @ 2017-05-29 12:08 UTC (permalink / raw)
  To: Michal Hocko, Andrew Morton
  Cc: linux-mm, Mel Gorman, Andrea Arcangeli, Jerome Glisse,
	Reza Arbab, Yasuaki Ishimatsu, qiuxishi, Kani Toshimitsu, slaoub,
	Joonsoo Kim, Andi Kleen, David Rientjes, Daniel Kiper,
	Igor Mammedov, Vitaly Kuznetsov, LKML, Michal Hocko

On 05/29/2017 01:41 PM, Michal Hocko wrote:
> From: Michal Hocko <mhocko@suse.com>
> 
> 20b2f52b73fe ("numa: add CONFIG_MOVABLE_NODE for movable-dedicated
> node") has introduced CONFIG_MOVABLE_NODE without a good explanation on
> why it is actually useful. It makes a lot of sense to make movable node
> semantic opt in but we already have that because the feature has to be
> explicitly enabled on the kernel command line. A config option on top
> only makes the configuration space larger without a good reason. It also
> adds an additional ifdefery that pollutes the code. Just drop the config
> option and make it de-facto always enabled. This shouldn't introduce any
> change to the semantic.
> 
> Acked-by: Reza Arbab <arbab@linux.vnet.ibm.com>
> Signed-off-by: Michal Hocko <mhocko@suse.com>

Acked-by: Vlastimil Babka <vbabka@suse.cz>

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^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH 3/3] mm, memory_hotplug: move movable_node to the hotplug proper
  2017-05-29 11:41   ` Michal Hocko
@ 2017-05-29 12:08     ` Vlastimil Babka
  -1 siblings, 0 replies; 14+ messages in thread
From: Vlastimil Babka @ 2017-05-29 12:08 UTC (permalink / raw)
  To: Michal Hocko, Andrew Morton
  Cc: linux-mm, Mel Gorman, Andrea Arcangeli, Jerome Glisse,
	Reza Arbab, Yasuaki Ishimatsu, qiuxishi, Kani Toshimitsu, slaoub,
	Joonsoo Kim, Andi Kleen, David Rientjes, Daniel Kiper,
	Igor Mammedov, Vitaly Kuznetsov, LKML, Michal Hocko

On 05/29/2017 01:41 PM, Michal Hocko wrote:
> From: Michal Hocko <mhocko@suse.com>
> 
> movable_node_is_enabled is defined in memblock proper while it
> is initialized from the memory hotplug proper. This is quite messy
> and it makes a dependency between the two so move movable_node along
> with the helper functions to memory_hotplug.
> 
> To make it more entertaining the kernel parameter is ignored unless
> CONFIG_HAVE_MEMBLOCK_NODE_MAP=y because we do not have the node
> information for each memblock otherwise. So let's warn when the option
> is disabled.
> 
> Acked-by: Vlastimil Babka <vbabka@suse.cz>
> Signed-off-by: Michal Hocko <mhocko@suse.com>

Acked-by: Vlastimil Babka <vbabka@suse.cz>

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH 3/3] mm, memory_hotplug: move movable_node to the hotplug proper
@ 2017-05-29 12:08     ` Vlastimil Babka
  0 siblings, 0 replies; 14+ messages in thread
From: Vlastimil Babka @ 2017-05-29 12:08 UTC (permalink / raw)
  To: Michal Hocko, Andrew Morton
  Cc: linux-mm, Mel Gorman, Andrea Arcangeli, Jerome Glisse,
	Reza Arbab, Yasuaki Ishimatsu, qiuxishi, Kani Toshimitsu, slaoub,
	Joonsoo Kim, Andi Kleen, David Rientjes, Daniel Kiper,
	Igor Mammedov, Vitaly Kuznetsov, LKML, Michal Hocko

On 05/29/2017 01:41 PM, Michal Hocko wrote:
> From: Michal Hocko <mhocko@suse.com>
> 
> movable_node_is_enabled is defined in memblock proper while it
> is initialized from the memory hotplug proper. This is quite messy
> and it makes a dependency between the two so move movable_node along
> with the helper functions to memory_hotplug.
> 
> To make it more entertaining the kernel parameter is ignored unless
> CONFIG_HAVE_MEMBLOCK_NODE_MAP=y because we do not have the node
> information for each memblock otherwise. So let's warn when the option
> is disabled.
> 
> Acked-by: Vlastimil Babka <vbabka@suse.cz>
> Signed-off-by: Michal Hocko <mhocko@suse.com>

Acked-by: Vlastimil Babka <vbabka@suse.cz>

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
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^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH 3/3] mm, memory_hotplug: move movable_node to the hotplug proper
  2017-05-29 11:41   ` Michal Hocko
@ 2017-05-30 15:05     ` Reza Arbab
  -1 siblings, 0 replies; 14+ messages in thread
From: Reza Arbab @ 2017-05-30 15:05 UTC (permalink / raw)
  To: Michal Hocko
  Cc: Andrew Morton, linux-mm, Mel Gorman, Vlastimil Babka,
	Andrea Arcangeli, Jerome Glisse, Yasuaki Ishimatsu, qiuxishi,
	Kani Toshimitsu, slaoub, Joonsoo Kim, Andi Kleen, David Rientjes,
	Daniel Kiper, Igor Mammedov, Vitaly Kuznetsov, LKML,
	Michal Hocko

On Mon, May 29, 2017 at 01:41:41PM +0200, Michal Hocko wrote:
>movable_node_is_enabled is defined in memblock proper while it
>is initialized from the memory hotplug proper. This is quite messy
>and it makes a dependency between the two so move movable_node along
>with the helper functions to memory_hotplug.
>
>To make it more entertaining the kernel parameter is ignored unless
>CONFIG_HAVE_MEMBLOCK_NODE_MAP=y because we do not have the node
>information for each memblock otherwise. So let's warn when the option
>is disabled.

Acked-by: Reza Arbab <arbab@linux.vnet.ibm.com>

-- 
Reza Arbab

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH 3/3] mm, memory_hotplug: move movable_node to the hotplug proper
@ 2017-05-30 15:05     ` Reza Arbab
  0 siblings, 0 replies; 14+ messages in thread
From: Reza Arbab @ 2017-05-30 15:05 UTC (permalink / raw)
  To: Michal Hocko
  Cc: Andrew Morton, linux-mm, Mel Gorman, Vlastimil Babka,
	Andrea Arcangeli, Jerome Glisse, Yasuaki Ishimatsu, qiuxishi,
	Kani Toshimitsu, slaoub, Joonsoo Kim, Andi Kleen, David Rientjes,
	Daniel Kiper, Igor Mammedov, Vitaly Kuznetsov, LKML,
	Michal Hocko

On Mon, May 29, 2017 at 01:41:41PM +0200, Michal Hocko wrote:
>movable_node_is_enabled is defined in memblock proper while it
>is initialized from the memory hotplug proper. This is quite messy
>and it makes a dependency between the two so move movable_node along
>with the helper functions to memory_hotplug.
>
>To make it more entertaining the kernel parameter is ignored unless
>CONFIG_HAVE_MEMBLOCK_NODE_MAP=y because we do not have the node
>information for each memblock otherwise. So let's warn when the option
>is disabled.

Acked-by: Reza Arbab <arbab@linux.vnet.ibm.com>

-- 
Reza Arbab

--
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	[flat|nested] 14+ messages in thread

end of thread, other threads:[~2017-05-30 15:05 UTC | newest]

Thread overview: 14+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-05-29 11:41 [PATCH 0/2] remove CONFIG_MOVABLE_NODE Michal Hocko
2017-05-29 11:41 ` Michal Hocko
2017-05-29 11:41 ` [PATCH 1/3] mm, memory_hotplug: drop artificial restriction on online/offline Michal Hocko
2017-05-29 11:41   ` Michal Hocko
2017-05-29 11:41 ` [PATCH 2/3] mm, memory_hotplug: drop CONFIG_MOVABLE_NODE Michal Hocko
2017-05-29 11:41   ` Michal Hocko
2017-05-29 12:08   ` Vlastimil Babka
2017-05-29 12:08     ` Vlastimil Babka
2017-05-29 11:41 ` [PATCH 3/3] mm, memory_hotplug: move movable_node to the hotplug proper Michal Hocko
2017-05-29 11:41   ` Michal Hocko
2017-05-29 12:08   ` Vlastimil Babka
2017-05-29 12:08     ` Vlastimil Babka
2017-05-30 15:05   ` Reza Arbab
2017-05-30 15:05     ` Reza Arbab

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