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Date: Wed, 13 Nov 2013 16:38:06 +0900
From: Tejun Heo <tj@kernel.org>
To: Hugh Dickins <hughd@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>,
	Li Zefan <lizefan@huawei.com>,
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	Yinghai Lu <yinghai@kernel.org>,
	"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>
Subject: Re: Possible regression with cgroups in 3.11
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Sender: linux-pci-owner@vger.kernel.org
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Hey, guys.

cc'ing people from "workqueue, pci: INFO: possible recursive locking
detected" thread.

  http://thread.gmane.org/gmane.linux.kernel/1525779

So, to resolve that issue, we ripped out lockdep annotation from
work_on_cpu() and cgroup is now experiencing deadlock involving
work_on_cpu().  It *could* be that workqueue is actually broken or
memcg is looping but it doesn't seem like a very good idea to not have
lockdep annotation around work_on_cpu().

IIRC, there was one pci code path which called work_on_cpu()
recursively.  Would it be possible for that path to use something like
work_on_cpu_nested(XXX, depth) so that we can retain lockdep
annotation on work_on_cpu()?

Thanks.

-- 
tejun