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Date: Thu, 06 May 2010 11:33:59 -0400
From: Rik van Riel <riel@redhat.com>
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To: Mel Gorman <mel@csn.ul.ie>
CC: Andrew Morton <akpm@linux-foundation.org>,
       Andrea Arcangeli <aarcange@redhat.com>,
       Christoph Lameter <cl@linux-foundation.org>,
       Adam Litke <agl@us.ibm.com>, Avi Kivity <avi@redhat.com>,
       David Rientjes <rientjes@google.com>,
       Minchan Kim <minchan.kim@gmail.com>,
       KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
       KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
       linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH] mm,compaction: Do not schedule work on other CPUs for
 compaction
References: <20100506150808.GC8704@csn.ul.ie>
In-Reply-To: <20100506150808.GC8704@csn.ul.ie>
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On 05/06/2010 11:08 AM, Mel Gorman wrote:
> Migration normally requires a call to migrate_prep() as a preparation
> step. This schedules work on all CPUs for pagevecs to be drained. This
> makes sense for move_pages and memory hot-remove but is unnecessary
> for memory compaction.
>
> To avoid queueing work on multiple CPUs, this patch introduces
> migrate_prep_local() which drains just local pagevecs.
>
> This patch can be either merged with mmcompaction-memory-compaction-core.patch
> or placed immediately after it to clarify why migrate_prep_local() was
> introduced.
>
> Signed-off-by: Mel Gorman<mel@csn.ul.ie>

Reviewed-by: Rik van Riel <riel@redhat.com>