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author | Hugh Dickins | 2014-02-07 00:56:01 +0100 |
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committer | Tejun Heo | 2014-02-07 16:21:12 +0100 |
commit | ab3f5faa6255a0eb4f832675507d9e295ca7e9ba (patch) | |
tree | 1f9a906214d8f20bf9f58ccb202d2eb8dade8db4 /kernel/rcu/tiny.c | |
parent | nfs: include xattr.h from fs/nfs/nfs3proc.c (diff) | |
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cgroup: use an ordered workqueue for cgroup destruction
Sometimes the cleanup after memcg hierarchy testing gets stuck in
mem_cgroup_reparent_charges(), unable to bring non-kmem usage down to 0.
There may turn out to be several causes, but a major cause is this: the
workitem to offline parent can get run before workitem to offline child;
parent's mem_cgroup_reparent_charges() circles around waiting for the
child's pages to be reparented to its lrus, but it's holding cgroup_mutex
which prevents the child from reaching its mem_cgroup_reparent_charges().
Just use an ordered workqueue for cgroup_destroy_wq.
tj: Committing as the temporary fix until the reverse dependency can
be removed from memcg. Comment updated accordingly.
Fixes: e5fca243abae ("cgroup: use a dedicated workqueue for cgroup destruction")
Suggested-by: Filipe Brandenburger <filbranden@google.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel/rcu/tiny.c')
0 files changed, 0 insertions, 0 deletions