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Commit 230e9fc2 authored by Vladimir Davydov's avatar Vladimir Davydov Committed by Linus Torvalds
Browse files

slab: add SLAB_ACCOUNT flag 



Currently, if we want to account all objects of a particular kmem cache,
we have to pass __GFP_ACCOUNT to each kmem_cache_alloc call, which is
inconvenient.  This patch introduces SLAB_ACCOUNT flag which if passed
to kmem_cache_create will force accounting for every allocation from
this cache even if __GFP_ACCOUNT is not passed.

This patch does not make any of the existing caches use this flag - it
will be done later in the series.

Note, a cache with SLAB_ACCOUNT cannot be merged with a cache w/o
SLAB_ACCOUNT, because merged caches share the same kmem_cache struct and
hence cannot have different sets of SLAB_* flags.  Thus using this flag
will probably reduce the number of merged slabs even if kmem accounting
is not used (only compiled in).

Signed-off-by: default avatarVladimir Davydov <vdavydov@virtuozzo.com>
Suggested-by: default avatarTejun Heo <tj@kernel.org>
Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent a9bb7e62

include/linux/memcontrol.h

+7 −8
Original line number Diff line number Diff line
@@ -766,15 +766,13 @@ static inline int memcg_cache_id(struct mem_cgroup *memcg) 
	return memcg ? memcg->kmemcg_id : -1;

}



struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep);

struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp);

void __memcg_kmem_put_cache(struct kmem_cache *cachep);



static inline bool __memcg_kmem_bypass(gfp_t gfp)

static inline bool __memcg_kmem_bypass(void)

{

	if (!memcg_kmem_enabled())

		return true;

	if (!(gfp & __GFP_ACCOUNT))

		return true;

	if (in_interrupt() || (!current->mm) || (current->flags & PF_KTHREAD))

		return true;

	return false;
@@ -791,7 +789,9 @@ static inline bool __memcg_kmem_bypass(gfp_t gfp) 
static __always_inline int memcg_kmem_charge(struct page *page,

					     gfp_t gfp, int order)

{

	if (__memcg_kmem_bypass(gfp))

	if (__memcg_kmem_bypass())

		return 0;

	if (!(gfp & __GFP_ACCOUNT))

		return 0;

	return __memcg_kmem_charge(page, gfp, order);

}
@@ -810,16 +810,15 @@ static __always_inline void memcg_kmem_uncharge(struct page *page, int order) 
/**

 * memcg_kmem_get_cache: selects the correct per-memcg cache for allocation

 * @cachep: the original global kmem cache

 * @gfp: allocation flags.

 *

 * All memory allocated from a per-memcg cache is charged to the owner memcg.

 */

static __always_inline struct kmem_cache *

memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)

{

	if (__memcg_kmem_bypass(gfp))

	if (__memcg_kmem_bypass())

		return cachep;

	return __memcg_kmem_get_cache(cachep);

	return __memcg_kmem_get_cache(cachep, gfp);

}



static __always_inline void memcg_kmem_put_cache(struct kmem_cache *cachep)

include/linux/slab.h

+5 −0
Original line number Diff line number Diff line
@@ -86,6 +86,11 @@ 
#else

# define SLAB_FAILSLAB		0x00000000UL

#endif

#ifdef CONFIG_MEMCG_KMEM

# define SLAB_ACCOUNT		0x04000000UL	/* Account to memcg */

#else

# define SLAB_ACCOUNT		0x00000000UL

#endif



/* The following flags affect the page allocator grouping pages by mobility */

#define SLAB_RECLAIM_ACCOUNT	0x00020000UL		/* Objects are reclaimable */

mm/memcontrol.c

+7 −1
Original line number Diff line number Diff line
@@ -2356,7 +2356,7 @@ static void memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg, 
 * Can't be called in interrupt context or from kernel threads.

 * This function needs to be called with rcu_read_lock() held.

 */

struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep)

struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)

{

	struct mem_cgroup *memcg;

	struct kmem_cache *memcg_cachep;
@@ -2364,6 +2364,12 @@ struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep) 


	VM_BUG_ON(!is_root_cache(cachep));



	if (cachep->flags & SLAB_ACCOUNT)

		gfp |= __GFP_ACCOUNT;



	if (!(gfp & __GFP_ACCOUNT))

		return cachep;



	if (current->memcg_kmem_skip_account)

		return cachep;

mm/slab.h

+3 −2
Original line number Diff line number Diff line
@@ -128,10 +128,11 @@ static inline unsigned long kmem_cache_flags(unsigned long object_size, 


#if defined(CONFIG_SLAB)

#define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \

			  SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | SLAB_NOTRACK)

			  SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | \

			  SLAB_NOTRACK | SLAB_ACCOUNT)

#elif defined(CONFIG_SLUB)

#define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \

			  SLAB_TEMPORARY | SLAB_NOTRACK)

			  SLAB_TEMPORARY | SLAB_NOTRACK | SLAB_ACCOUNT)

#else

#define SLAB_CACHE_FLAGS (0)

#endif

mm/slab_common.c

+2 −1
Original line number Diff line number Diff line
@@ -37,7 +37,8 @@ struct kmem_cache *kmem_cache; 
		SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE | \

		SLAB_FAILSLAB)



#define SLAB_MERGE_SAME (SLAB_RECLAIM_ACCOUNT | SLAB_CACHE_DMA | SLAB_NOTRACK)

#define SLAB_MERGE_SAME (SLAB_RECLAIM_ACCOUNT | SLAB_CACHE_DMA | \

			 SLAB_NOTRACK | SLAB_ACCOUNT)



/*

 * Merge control. If this is set then no merging of slab caches will occur.