Commit 33a690c4 authored by Vladimir Davydov's avatar Vladimir Davydov Committed by Linus Torvalds
Browse files

memcg: move memcg_{alloc,free}_cache_params to slab_common.c 



The only reason why they live in memcontrol.c is that we get/put css
reference to the owner memory cgroup in them.  However, we can do that in
memcg_{un,}register_cache.  OTOH, there are several reasons to move them
to slab_common.c.

First, I think that the less public interface functions we have in
memcontrol.h the better.  Since the functions I move don't depend on
memcontrol, I think it's worth making them private to slab, especially
taking into account that the arrays are defined on the slab's side too.

Second, the way how per-memcg arrays are updated looks rather awkward: it
proceeds from memcontrol.c (__memcg_activate_kmem) to slab_common.c
(memcg_update_all_caches) and back to memcontrol.c again
(memcg_update_array_size).  In the following patches I move the function
relocating the arrays (memcg_update_array_size) to slab_common.c and
therefore get rid this circular call path.  I think we should have the
cache allocation stuff in the same place where we have relocation, because
it's easier to follow the code then.  So I move arrays alloc/free
functions to slab_common.c too.

The third point isn't obvious.  I'm going to make the list_lru structure
per-memcg to allow targeted kmem reclaim.  That means we will have
per-memcg arrays in list_lrus too.  It turns out that it's much easier to
update these arrays in list_lru.c rather than in memcontrol.c, because all
the stuff we need is defined there.  This patch makes memcg caches arrays
allocation path conform that of the upcoming list_lru.

So let's move these functions to slab_common.c and make them static.

Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Acked-by: default avatarMichal Hocko <mhocko@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7a82ca0d

include/linux/memcontrol.h

+0 −14
Original line number Diff line number Diff line
@@ -440,10 +440,6 @@ void __memcg_kmem_uncharge_pages(struct page *page, int order); 


int memcg_cache_id(struct mem_cgroup *memcg);



int memcg_alloc_cache_params(struct mem_cgroup *memcg, struct kmem_cache *s,

			     struct kmem_cache *root_cache);

void memcg_free_cache_params(struct kmem_cache *s);



int memcg_update_cache_size(struct kmem_cache *s, int num_groups);

void memcg_update_array_size(int num_groups);
@@ -574,16 +570,6 @@ static inline int memcg_cache_id(struct mem_cgroup *memcg) 
	return -1;

}



static inline int memcg_alloc_cache_params(struct mem_cgroup *memcg,

		struct kmem_cache *s, struct kmem_cache *root_cache)

{

	return 0;

}



static inline void memcg_free_cache_params(struct kmem_cache *s)

{

}



static inline struct kmem_cache *

memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)

{

mm/memcontrol.c

+4 −37
Original line number Diff line number Diff line
@@ -2984,43 +2984,6 @@ int memcg_update_cache_size(struct kmem_cache *s, int num_groups) 
	return 0;

}



int memcg_alloc_cache_params(struct mem_cgroup *memcg, struct kmem_cache *s,

			     struct kmem_cache *root_cache)

{

	size_t size;



	if (!memcg_kmem_enabled())

		return 0;



	if (!memcg) {

		size = offsetof(struct memcg_cache_params, memcg_caches);

		size += memcg_limited_groups_array_size * sizeof(void *);

	} else

		size = sizeof(struct memcg_cache_params);



	s->memcg_params = kzalloc(size, GFP_KERNEL);

	if (!s->memcg_params)

		return -ENOMEM;



	if (memcg) {

		s->memcg_params->memcg = memcg;

		s->memcg_params->root_cache = root_cache;

		css_get(&memcg->css);

	} else

		s->memcg_params->is_root_cache = true;



	return 0;

}



void memcg_free_cache_params(struct kmem_cache *s)

{

	if (!s->memcg_params)

		return;

	if (!s->memcg_params->is_root_cache)

		css_put(&s->memcg_params->memcg->css);

	kfree(s->memcg_params);

}



static void memcg_register_cache(struct mem_cgroup *memcg,

				 struct kmem_cache *root_cache)

{
@@ -3051,6 +3014,7 @@ static void memcg_register_cache(struct mem_cgroup *memcg, 
	if (!cachep)

		return;



	css_get(&memcg->css);

	list_add(&cachep->memcg_params->list, &memcg->memcg_slab_caches);



	/*
@@ -3084,6 +3048,9 @@ static void memcg_unregister_cache(struct kmem_cache *cachep) 
	list_del(&cachep->memcg_params->list);



	kmem_cache_destroy(cachep);



	/* drop the reference taken in memcg_register_cache */

	css_put(&memcg->css);

}



/*

mm/slab_common.c

+43 −1
Original line number Diff line number Diff line
@@ -116,6 +116,38 @@ static inline int kmem_cache_sanity_check(const char *name, size_t size) 
#endif



#ifdef CONFIG_MEMCG_KMEM

static int memcg_alloc_cache_params(struct mem_cgroup *memcg,

		struct kmem_cache *s, struct kmem_cache *root_cache)

{

	size_t size;



	if (!memcg_kmem_enabled())

		return 0;



	if (!memcg) {

		size = offsetof(struct memcg_cache_params, memcg_caches);

		size += memcg_limited_groups_array_size * sizeof(void *);

	} else

		size = sizeof(struct memcg_cache_params);



	s->memcg_params = kzalloc(size, GFP_KERNEL);

	if (!s->memcg_params)

		return -ENOMEM;



	if (memcg) {

		s->memcg_params->memcg = memcg;

		s->memcg_params->root_cache = root_cache;

	} else

		s->memcg_params->is_root_cache = true;



	return 0;

}



static void memcg_free_cache_params(struct kmem_cache *s)

{

	kfree(s->memcg_params);

}



int memcg_update_all_caches(int num_memcgs)

{

	struct kmem_cache *s;
@@ -141,7 +173,17 @@ out: 
	mutex_unlock(&slab_mutex);

	return ret;

}

#endif

#else

static inline int memcg_alloc_cache_params(struct mem_cgroup *memcg,

		struct kmem_cache *s, struct kmem_cache *root_cache)

{

	return 0;

}



static inline void memcg_free_cache_params(struct kmem_cache *s)

{

}

#endif /* CONFIG_MEMCG_KMEM */



/*

 * Find a mergeable slab cache

CRA Git | Maintained and supported by SUSTech CRA and CCSE