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From: Andrew Morton <akpm@linux-foundation.org>
To: Jacobo Giralt <jacobo.giralt@gmail.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	mgorman@suse.de, minchan.kim@gmail.com, hughd@google.com,
	hannes@cmpxchg.org, Nick Piggin <npiggin@kernel.dk>
Subject: Re: [PATCH] mm: migrate: One less atomic operation
Date: Tue, 8 Nov 2011 14:57:06 -0800	[thread overview]
Message-ID: <20111108145706.11da104e.akpm@linux-foundation.org> (raw)
In-Reply-To: <1320503897.2428.8.camel@discretia>

On Sat, 05 Nov 2011 15:38:17 +0100
Jacobo Giralt <jacobo.giralt@gmail.com> wrote:

> >From 3754c8617ef4377ce2ca2e3b28bdc28f8de1aa0d Mon Sep 17 00:00:00 2001
> From: Jacobo Giralt <jacobo.giralt@gmail.com>
> Date: Sat, 5 Nov 2011 13:12:50 +0100
> Subject: [PATCH] mm: migrate: One less atomic operation
> 
> migrate_page_move_mapping drops a reference from the
> old page after unfreezing its counter. Both operations
> can be merged into a single atomic operation by
> directly unfreezing to one less reference.
> 
> The same applies to migrate_huge_page_move_mapping.
> 

Fair enough.

urgh, you made me look at stuff :(

page_unfreeze_refs() and set_page_refcounted() are fishily similar.

page_unfreeze_refs() should use set_page_count().

set_page_count() is defined in the wrong file.

set_page_refcounted() should use page_count().

iow, a bit of a mess.

WARNING: multiple messages have this Message-ID (diff)
From: Andrew Morton <akpm@linux-foundation.org>
To: Jacobo Giralt <jacobo.giralt@gmail.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	mgorman@suse.de, minchan.kim@gmail.com, hughd@google.com,
	hannes@cmpxchg.org, Nick Piggin <npiggin@kernel.dk>
Subject: Re: [PATCH] mm: migrate: One less atomic operation
Date: Tue, 8 Nov 2011 14:57:06 -0800	[thread overview]
Message-ID: <20111108145706.11da104e.akpm@linux-foundation.org> (raw)
In-Reply-To: <1320503897.2428.8.camel@discretia>

On Sat, 05 Nov 2011 15:38:17 +0100
Jacobo Giralt <jacobo.giralt@gmail.com> wrote:

> >From 3754c8617ef4377ce2ca2e3b28bdc28f8de1aa0d Mon Sep 17 00:00:00 2001
> From: Jacobo Giralt <jacobo.giralt@gmail.com>
> Date: Sat, 5 Nov 2011 13:12:50 +0100
> Subject: [PATCH] mm: migrate: One less atomic operation
> 
> migrate_page_move_mapping drops a reference from the
> old page after unfreezing its counter. Both operations
> can be merged into a single atomic operation by
> directly unfreezing to one less reference.
> 
> The same applies to migrate_huge_page_move_mapping.
> 

Fair enough.

urgh, you made me look at stuff :(

page_unfreeze_refs() and set_page_refcounted() are fishily similar.

page_unfreeze_refs() should use set_page_count().

set_page_count() is defined in the wrong file.

set_page_refcounted() should use page_count().

iow, a bit of a mess.

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  parent reply	other threads:[~2011-11-08 22:57 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-11-05 14:38 [PATCH] mm: migrate: One less atomic operation Jacobo Giralt
2011-11-05 14:38 ` Jacobo Giralt
2011-11-05 14:48 ` Jacobo Giralt
2011-11-05 14:48   ` Jacobo Giralt
2011-11-08 22:57 ` Andrew Morton [this message]
2011-11-08 22:57   ` Andrew Morton

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