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Date:   Fri, 3 Apr 2020 10:54:18 -0400
From:   Tejun Heo <tj@kernel.org>
To:     Qian Cai <cai@lca.pw>
Cc:     Prateek Sood <prsood@codeaurora.org>,
        Li Zefan <lizefan@huawei.com>, cgroups@vger.kernel.org,
        LKML <linux-kernel@vger.kernel.org>,
        Peter Zijlstra <peterz@infradead.org>
Subject: Re: Deadlock due to "cpuset: Make cpuset hotplug synchronous"
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On Wed, Apr 01, 2020 at 10:00:31PM -0400, Qian Cai wrote:
> 
> 
> > On Mar 25, 2020, at 3:19 PM, Tejun Heo <tj@kernel.org> wrote:
> > 
> > On Wed, Mar 25, 2020 at 03:16:56PM -0400, Qian Cai wrote:
> >> The linux-next commit a49e4629b5ed (“cpuset: Make cpuset hotplug synchronous”)
> >> introduced real deadlocks with CPU hotplug as showed in the lockdep splat, since it is
> >> now making a relation from cpu_hotplug_lock —> 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.
> 
> Tejun, can you back off this commit now given it seems nobody is trying to rescue it?

Yeah, gonna revert it before sending out the pull request.

Thanks.

-- 
tejun