Re: [PATCH] cgroup: Fix deadlock in cpu hotplug path

From: Tejun Heo
Date: Tue Dec 19 2017 - 08:40:08 EST


On Tue, Dec 19, 2017 at 12:56:57PM +0530, Prateek Sood wrote:
> Deadlock during cgroup migration from cpu hotplug path when a task T is
> being moved from source to destination cgroup.
...
> Task T inserted a work item in the worklist of cpu0 low priority
> worker pool. It is waiting for expedited grace period work item
> to execute. This work item will only be executed once kworker/0:0
> complete execution of cpuset_hotplug_workfn().
>
> kworker/0:0 ==> Task T ==>kworker/0:0
>
> In case of PF_EXITING task being migrated from source to destination
> cgroup, migrate next available task in source cgroup.
>
> Change-Id: I8874fb04479c136cae4dabd5c168c7749df66664
> Signed-off-by: Prateek Sood <prsood@xxxxxxxxxxxxxx>

Applied to cgroup/for-4.15-fixes.

Thanks a lot, Prateek.

--
tejun