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Date: Thu, 3 Apr 2003 12:56:34 -0800
From: Andrew Morton <akpm@digeo.com>
To: dmccr@us.ibm.com
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2.5.66-mm2] Fix page_convert_anon locking issues
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Andrew Morton <akpm@digeo.com> wrote:
>
> page_referenced() has the same problem, so refill_inactive_zone() will need
> to lock pages too.

Complete bollocks.  As long as the pte chains are consistent while
refill_inactive_zone holds pte_chain_lock (they darn well should be),
concurrent page_referenced() and page_convert_anon() is fine.

It could be that page_referenced() returns an inappropriate answer, but it's
so rare we don't care.

Which is good.  We really don't want to lock pages in refill_inactive_zone()
to keep the extremely rare page_convert_anon() away.  refill_inactive_zone()
is more a bath-temperature path than a hotpath, but still...