From mboxrd@z Thu Jan  1 00:00:00 1970
From: Tejun Heo <tj@kernel.org>
Subject: Re: [RFC PATCH] cgroup, netclassid: add a preemption point to
 write_classid
Date: Tue, 23 Oct 2018 12:58:48 -0700
Message-ID: <20181023195848.GC4182586@devbig004.ftw2.facebook.com>
References: <20181018085617.28456-1-mhocko@kernel.org>
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To: Michal Hocko <mhocko@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>, Johannes Weiner <hannes@cmpxchg.org>, cgroups@vger.kernel.org, netdev@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>, Michal Hocko <mhocko@suse.com>

On Thu, Oct 18, 2018 at 10:56:17AM +0200, Michal Hocko wrote:
> From: Michal Hocko <mhocko@suse.com>
> 
> We have seen a customer complaining about soft lockups on !PREEMPT
> kernel config with 4.4 based kernel
...
> If a cgroup has many tasks with many open file descriptors then we would
> end up in a large loop without any rescheduling point throught the
> operation. Add cond_resched once per task.
> 
> Signed-off-by: Michal Hocko <mhocko@suse.com>

Applied to cgroup/for-4.20.

Thanks.

-- 
tejun