mm/memcg: set memcg after css verified and got reference

Patch series "mm/memcg: some cleanup for mem_cgroup_iter()", v2.

No functional change, try to make it more readable.


This patch (of 3):

Instead of resetting memcg when css is either not verified or not got
reference, we can set it after these process.

No functional change, just simplified the code a little.

Link: https://lkml.kernel.org/r/20220330234719.18340-1-richard.weiyang@gmail.com
Link: https://lkml.kernel.org/r/20220330234719.18340-2-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Wei Yang 2022-04-28 23:15:58 -07:00 committed by akpm
parent 391e0efc15
commit 41555dadbf

View file

@ -1065,15 +1065,10 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
* is provided by the caller, so we know it's alive
* and kicking, and don't take an extra reference.
*/
memcg = mem_cgroup_from_css(css);
if (css == &root->css)
if (css == &root->css || css_tryget(css)) {
memcg = mem_cgroup_from_css(css);
break;
if (css_tryget(css))
break;
memcg = NULL;
}
}
if (reclaim) {