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Date: Thu, 20 May 2010 10:30:21 +0200
From: Tejun Heo <tj@kernel.org>
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To: Oleg Nesterov <oleg@redhat.com>
CC: "Rafael J. Wysocki" <rjw@sisk.pl>,
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       Alan Stern <stern@rowland.harvard.edu>, Len Brown <len.brown@intel.com>,
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       Andrew Morton <akpm@linux-foundation.org>,
       Maxim Levitsky <maximlevitsky@gmail.com>, linux-doc@vger.kernel.org
Subject: Re: [PATCH 1/8] PM: Add suspend block api.
References: <1272429119-12103-1-git-send-email-arve@android.com> <201004282250.44200.rjw@sisk.pl> <l2yd6200be21004282037rc063266by91db7f732ceaa529@mail.gmail.com> <201004292316.14524.rjw@sisk.pl> <4BDA5B8B.50004@kernel.org> <20100430172618.GA9043@redhat.com>
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Hello,

(sorry about late reply)

On 04/30/2010 07:26 PM, Oleg Nesterov wrote:
> Currently _cpu_down() can't flush and/or stop the frozen cwq->thread.
> 
> IIRC this is fixable, but needs the nasty complications. We should
> thaw + stop the frozen cwq->thread, then move the pending works to
> another CPU.

Oh, this isn't an issue w/ cmwq.  While frozen all new works are
collected into per-cpu delayed worklist and while frozen trustee in
charge of the cpu will keep waiting.  Once thawed, trustee will
execute all works including the delayed ones unbound to any cpu.

Thanks.

-- 
tejun