From mboxrd@z Thu Jan  1 00:00:00 1970
From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Subject: Re: Why PAGEOUT_IO_SYNC stalls for a long time
Date: Sun,  1 Aug 2010 17:47:08 +0900 (JST)
Message-ID: <20100801174229.4B08.A69D9226@jp.fujitsu.com>
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Cc: kosaki.motohiro@jp.fujitsu.com,
	Wu Fengguang <fengguang.wu@intel.com>,
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	KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
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To: Mel Gorman <mel@csn.ul.ie>
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> > side note: page lock contention is very common case.
> > 
> > For case (8), I don't think sleeping is right way. get_page() is used in really various place of
> > our kernel. so we can't assume it's only temporary reference count increasing.
> 
> In what case is a munlocked pages reference count permanently increased and
> why is this not a memory leak?

V4L, audio, GEM and/or other multimedia driver?