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authorLi Zefan <lizefan@huawei.com>2013-07-08 19:00:31 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2013-07-09 13:33:24 -0400
commit20f05310ba62d5816fb339d08effe78683137197 (patch)
tree2909c3e1ef2091dfd45fc674ab48d21871555aca /mm
parent5347e5ae13710420eebbbd0b22c045685704da80 (diff)
memcg: don't use mem_cgroup_get() when creating a kmemcg cache
Use css_get()/css_put() instead of mem_cgroup_get()/mem_cgroup_put(). There are two things being done in the current code: First, we acquired a css_ref to make sure that the underlying cgroup would not go away. That is a short lived reference, and it is put as soon as the cache is created. At this point, we acquire a long-lived per-cache memcg reference count to guarantee that the memcg will still be alive. so it is: enqueue: css_get create : memcg_get, css_put destroy: memcg_put So we only need to get rid of the memcg_get, change the memcg_put to css_put, and get rid of the now extra css_put. (This changelog is mostly written by Glauber) Signed-off-by: Li Zefan <lizefan@huawei.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Glauber Costa <glommer@openvz.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/memcontrol.c10
1 files changed, 5 insertions, 5 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 4c31a21a55be..80175ded718d 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3242,7 +3242,7 @@ void memcg_release_cache(struct kmem_cache *s)
3242 list_del(&s->memcg_params->list); 3242 list_del(&s->memcg_params->list);
3243 mutex_unlock(&memcg->slab_caches_mutex); 3243 mutex_unlock(&memcg->slab_caches_mutex);
3244 3244
3245 mem_cgroup_put(memcg); 3245 css_put(&memcg->css);
3246out: 3246out:
3247 kfree(s->memcg_params); 3247 kfree(s->memcg_params);
3248} 3248}
@@ -3402,16 +3402,18 @@ static struct kmem_cache *memcg_create_kmem_cache(struct mem_cgroup *memcg,
3402 3402
3403 mutex_lock(&memcg_cache_mutex); 3403 mutex_lock(&memcg_cache_mutex);
3404 new_cachep = cachep->memcg_params->memcg_caches[idx]; 3404 new_cachep = cachep->memcg_params->memcg_caches[idx];
3405 if (new_cachep) 3405 if (new_cachep) {
3406 css_put(&memcg->css);
3406 goto out; 3407 goto out;
3408 }
3407 3409
3408 new_cachep = kmem_cache_dup(memcg, cachep); 3410 new_cachep = kmem_cache_dup(memcg, cachep);
3409 if (new_cachep == NULL) { 3411 if (new_cachep == NULL) {
3410 new_cachep = cachep; 3412 new_cachep = cachep;
3413 css_put(&memcg->css);
3411 goto out; 3414 goto out;
3412 } 3415 }
3413 3416
3414 mem_cgroup_get(memcg);
3415 atomic_set(&new_cachep->memcg_params->nr_pages , 0); 3417 atomic_set(&new_cachep->memcg_params->nr_pages , 0);
3416 3418
3417 cachep->memcg_params->memcg_caches[idx] = new_cachep; 3419 cachep->memcg_params->memcg_caches[idx] = new_cachep;
@@ -3499,8 +3501,6 @@ static void memcg_create_cache_work_func(struct work_struct *w)
3499 3501
3500 cw = container_of(w, struct create_work, work); 3502 cw = container_of(w, struct create_work, work);
3501 memcg_create_kmem_cache(cw->memcg, cw->cachep); 3503 memcg_create_kmem_cache(cw->memcg, cw->cachep);
3502 /* Drop the reference gotten when we enqueued. */
3503 css_put(&cw->memcg->css);
3504 kfree(cw); 3504 kfree(cw);
3505} 3505}
3506 3506