From mboxrd@z Thu Jan  1 00:00:00 1970
From: Wu Fengguang <fengguang.wu@intel.com>
Subject: Re: [PATCH 05/10] vmscan: Synchrounous lumpy reclaim use
 lock_page() instead trylock_page()
Date: Thu, 9 Sep 2010 11:25:24 +0800
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Cc: Mel Gorman <mel@csn.ul.ie>,
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	Andrea Arcangeli <aarcange@redhat.com>,
	KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
	Dave Chinner <david@fromorbit.com>,
	Chris Mason <chris.mason@oracle.com>,
	Christoph Hellwig <hch@lst.de>,
	Andrew Morton <akpm@linux-foundation.org>
To: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
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On Thu, Sep 09, 2010 at 11:15:47AM +0800, KAMEZAWA Hiroyuki wrote:
> On Thu, 9 Sep 2010 12:04:48 +0900
> KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote:
> 
> > On Mon,  6 Sep 2010 11:47:28 +0100
> > Mel Gorman <mel@csn.ul.ie> wrote:
> > 
> > > From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
> > > 
> > > With synchrounous lumpy reclaim, there is no reason to give up to reclaim
> > > pages even if page is locked. This patch uses lock_page() instead of
> > > trylock_page() in this case.
> > > 
> > > Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
> > > Signed-off-by: Mel Gorman <mel@csn.ul.ie>
> > 
> > Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> > 
> Ah......but can't this change cause dead lock ??

You mean the task goes for page allocation while holding some page
lock? Seems possible.

Thanks,
Fengguang