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authorVladimir Davydov <vdavydov@virtuozzo.com>2016-03-01 19:56:30 +0300
committerMichael Bestas <mkbestas@lineageos.org>2022-04-19 00:50:54 +0300
commit97d8ea8e7771b56dac2f7620b79aa04d932c529b (patch)
treec55aa1bd597819c421d8e6ba457a0245c333309f
parent90c1aa475b3ae87aad48a6e076bce824e78ee060 (diff)
cgroup: reset css on destruction
An associated css can be around for quite a while after a cgroup directory has been removed. In general, it makes sense to reset it to defaults so as not to worry about any remnants. For instance, memory cgroup needs to reset memory.low, otherwise pages charged to a dead cgroup might never get reclaimed. There's ->css_reset callback, which would fit perfectly for the purpose. Currently, it's only called when a subsystem is disabled in the unified hierarchy and there are other subsystems dependant on it. Let's call it on css destruction as well. Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Chatur27 <jasonbright2709@gmail.com>
-rw-r--r--kernel/cgroup.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index e51c5ef3fe27..a6d788b95002 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -4911,6 +4911,9 @@ static void offline_css(struct cgroup_subsys_state *css)
if (!(css->flags & CSS_ONLINE))
return;
+ if (ss->css_reset)
+ ss->css_reset(css);
+
if (ss->css_offline)
ss->css_offline(css);