Re: Deadlock due to "cpuset: Make cpuset hotplug synchronous"

From: Qais Yousef
Date: Thu Mar 26 2020 - 06:15:37 EST


On 03/25/20 15:19, Tejun Heo wrote:
> On Wed, Mar 25, 2020 at 03:16:56PM -0400, Qian Cai wrote:
> > The linux-next commit a49e4629b5ed (âcpuset: Make cpuset hotplug synchronousâ)
> > introduced real deadlocks with CPU hotplug as showed in the lockdep splat, since it is
> > now making a relation from cpu_hotplug_lock â> cgroup_mutex.
>
> Prateek, can you please take a look? Given that the merge window is just around
> the corner, we might have to revert and retry later if it can't be resolved
> quickly.

I've ran cpuset_hotplug and cpuhotplug LTP tests using next-20200325 but
couldn't reproduce it.

Hopefully that can be fixed, but if you had to revert it, do you mind picking
this instead to fix the LTP issue I encountered before?

https://lore.kernel.org/lkml/20200211141554.24181-1-qais.yousef@xxxxxxx/

Thanks!

--
Qais Yousef