On Thu, Feb 06, 2014 at 03:56:01PM -0800, Hugh Dickins wrote:
> 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.
>
> Fixes: e5fca243abae ("cgroup: use a dedicated workqueue for cgroup
> destruction")
> Suggested-by: Filipe Brandenburger <filbran...@google.com>
> Signed-off-by: Hugh Dickins <hu...@google.com>
> Cc: sta...@vger.kernel.org # 3.10+
Applied to cgroup/for-3.14-fixes with comment updated to indicate that
this is temporary.
Thanks.
--
tejun
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
