Messages in this thread Patch in this message |  | | Date | Fri, 7 Dec 2012 09:12:25 -0800 | Subject | Re: [patch v2 3/6] memcg: rework mem_cgroup_iter to use cgroup iterators | From | Ying Han <> |
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On Fri, Dec 7, 2012 at 12:58 AM, Michal Hocko <mhocko@suse.cz> wrote: > On Thu 06-12-12 19:43:52, Ying Han wrote: > [...] >> Forgot to mention, I was testing 3.7-rc6 with the two cgroup changes : > > Could you give a try to -mm tree as well. There are some changes for > memcgs removal in that tree which are not in Linus's tree.
I will give a try, which patchset you have in mind so i can double check?
I didn't find the place where the css pins the memcg, which either something i missed or not in place in my tree. I twisted the patch a bit to make it closer to your v2 version, but instead keep the mem_cgroup_put() as well as using css_tryget(). Again, my test is happy with it:
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index f2eeee6..acec05a 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1004,6 +1004,7 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, if (prev && reclaim->generation != iter->generation) { if (last_visited) { css_put(&last_visited->css); + mem_cgroup_put(last_visited); iter->last_visited = NULL; } spin_unlock(&iter->iter_lock); @@ -1041,15 +1042,22 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, if (reclaim) { struct mem_cgroup *curr = memcg;
- if (last_visited) + if (last_visited) { css_put(&last_visited->css); + mem_cgroup_put(last_visited); + }
if (css && !memcg) curr = container_of(css, struct mem_cgroup, css);
/* make sure that the cached memcg is not removed */ - if (curr) - css_get(&curr->css); + if (curr) { + mem_cgroup_get(curr); + if (!css_tryget(&curr->css)) { + mem_cgroup_put(curr); + curr = NULL; + } + } iter->last_visited = curr;
if (!css)
--Ying
> -- > Michal Hocko > SUSE Labs
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