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Subject: Re: Regression - locking (all from 2.6.28)
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>,
       Andrew Morton <akpm@linux-foundation.org>,
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Date: Thu, 05 Mar 2009 19:29:17 +0100
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On Thu, 2009-03-05 at 18:04 +0000, Catalin Marinas wrote:
> 
> BTW, is there a way to know whether the page is in use or on the free
> list? Is page_count(page) feasible?

page_count() == 0, means that the page is not used.
PageBuddy() means its on the freelist.