Subject: + memcg-dont-use-mem_cgroup_get-when-creating-a-kmemcg-cache.patch added to -mm tree
To: lizefan@xxxxxxxxxx,glommer@xxxxxxxxxx,hannes@xxxxxxxxxxx,hughd@xxxxxxxxxx,kamezawa.hiroyu@xxxxxxxxxxxxxx,mhocko@xxxxxxx,tj@xxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Fri, 28 Jun 2013 16:00:28 -0700
The patch titled
Subject: memcg: don't use mem_cgroup_get() when creating a kmemcg cache
has been added to the -mm tree. Its filename is
memcg-dont-use-mem_cgroup_get-when-creating-a-kmemcg-cache.patch
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------------------------------------------------------
From: Li Zefan <lizefan@xxxxxxxxxx>
Subject: 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@xxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxx>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Glauber Costa <glommer@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memcontrol.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff -puN mm/memcontrol.c~memcg-dont-use-mem_cgroup_get-when-creating-a-kmemcg-cache mm/memcontrol.c
--- a/mm/memcontrol.c~memcg-dont-use-mem_cgroup_get-when-creating-a-kmemcg-cache
+++ a/mm/memcontrol.c
@@ -3242,7 +3242,7 @@ void memcg_release_cache(struct kmem_cac
list_del(&s->memcg_params->list);
mutex_unlock(&memcg->slab_caches_mutex);
- mem_cgroup_put(memcg);
+ css_put(&memcg->css);
out:
kfree(s->memcg_params);
}
@@ -3402,16 +3402,18 @@ static struct kmem_cache *memcg_create_k
mutex_lock(&memcg_cache_mutex);
new_cachep = cachep->memcg_params->memcg_caches[idx];
- if (new_cachep)
+ if (new_cachep) {
+ css_put(&memcg->css);
goto out;
+ }
new_cachep = kmem_cache_dup(memcg, cachep);
if (new_cachep == NULL) {
new_cachep = cachep;
+ css_put(&memcg->css);
goto out;
}
- mem_cgroup_get(memcg);
atomic_set(&new_cachep->memcg_params->nr_pages , 0);
cachep->memcg_params->memcg_caches[idx] = new_cachep;
@@ -3499,8 +3501,6 @@ static void memcg_create_cache_work_func
cw = container_of(w, struct create_work, work);
memcg_create_kmem_cache(cw->memcg, cw->cachep);
- /* Drop the reference gotten when we enqueued. */
- css_put(&cw->memcg->css);
kfree(cw);
}
_
Patches currently in -mm which might be from lizefan@xxxxxxxxxx are
origin.patch
linux-next.patch
memcg-update-todo-list-in-documentation.patch
revert-memcg-avoid-dangling-reference-count-in-creation-failure.patch
memcg-kmem-fix-reference-count-handling-on-the-error-path.patch
memcg-use-css_get-in-sock_update_memcg.patch
memcg-dont-use-mem_cgroup_get-when-creating-a-kmemcg-cache.patch
memcg-use-css_get-put-when-charging-uncharging-kmem.patch
memcg-use-css_get-put-when-charging-uncharging-kmem-fix.patch
memcg-use-css_get-put-for-swap-memcg.patch
memcg-dont-need-to-get-a-reference-to-the-parent.patch
memcg-kill-memcg-refcnt.patch
memcg-dont-need-to-free-memcg-via-rcu-or-workqueue.patch
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