Re: [PATCH] migration: only migrate_prep() once per move_pages()

[Brice Goglin <Brice.Goglin@inria.fr>]

KAMEZAWA Hiroyuki wrote:
> On Wed, 15 Apr 2009 09:32:10 +0200
> Brice Goglin <Brice.Goglin@ens-lyon.org> wrote:
>
>   
>> migrate_prep() is fairly expensive (72us on 16-core barcelona 1.9GHz).
>> Commit 3140a2273009c01c27d316f35ab76a37e105fdd8 improved move_pages()
>> throughput by breaking it into chunks, but it also made migrate_prep()
>> be called once per chunk (every 128pages or so) instead of once per
>> move_pages().
>>
>> This patch reverts to calling migrate_prep() only once per chunk
>> as we did before 2.6.29.
>> It is also a followup to commit 0aedadf91a70a11c4a3e7c7d99b21e5528af8d5d
>>     mm: move migrate_prep out from under mmap_sem
>>
>> This improves migration throughput on the above machine from 600MB/s
>> to 750MB/s.
>>
>> Signed-off-by: Brice Goglin <Brice.Goglin@inria.fr>
>>
>>     
> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
>
> I think this patch is good. page migration is best-effort syscall ;)
>   

Since nobody complained about this patch, may I get a Ack and get the
patch merged for 2.6.31?

thanks,
Brice

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