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Date: Sat, 8 May 2004 23:22:39 +0100
From: Christoph Hellwig <hch@infradead.org>
To: Hugh Dickins <hugh@veritas.com>
Cc: Andrew Morton <akpm@osdl.org>, Andrea Arcangeli <andrea@suse.de>,
       linux-kernel@vger.kernel.org
Subject: Re: [PATCH] rmap 24 pte_young first
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	Hugh Dickins <hugh@veritas.com>, Andrew Morton <akpm@osdl.org>,
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In-Reply-To: <Pine.LNX.4.44.0405082255430.26569-100000@localhost.localdomain>; from hugh@veritas.com on Sat, May 08, 2004 at 10:56:26PM +0100
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On Sat, May 08, 2004 at 10:56:26PM +0100, Hugh Dickins wrote:
> From: Andrea Arcangeli <andrea@suse.de>
> 
> rmap test pte_young before doing the costlier ptep_test_and_clear_young.
> 
>  rmap.c |    6 +++---
>  1 files changed, 3 insertions(+), 3 deletions(-)
> 
> --- rmap24/mm/rmap.c	2004-05-08 20:54:32.421571016 +0100
> +++ rmap25/mm/rmap.c	2004-05-08 20:54:43.358908288 +0100
> @@ -198,7 +198,7 @@ static int page_referenced_one(struct pa
>  	if (page_to_pfn(page) != pte_pfn(*pte))
>  		goto out_unmap;
>  
> -	if (ptep_test_and_clear_young(pte))
> +	if (pte_young(*pte) && ptep_test_and_clear_young(pte))

stupid question - shouldn't the pte_young check simply move to
the beginning of ptep_test_and_clear_young?