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From: Jens Axboe <jens.axboe@oracle.com>
To: Richard Kennedy <richard@rsk.demon.co.uk>
Cc: fio <fio@vger.kernel.org>
Subject: Re: fio mmap writes much slower than default writes
Date: Sat, 18 Jul 2009 16:39:55 +0200	[thread overview]
Message-ID: <20090718143955.GJ4148@kernel.dk> (raw)
In-Reply-To: <1247925507.2712.11.camel@localhost.localdomain>

On Sat, Jul 18 2009, Richard Kennedy wrote:
> Disk stats (read/write):
>   dm-0: ios=3571/9894, merge=0/0, ticks=25884/31650, in_queue=511733, util=96.46%, aggrios=0/0, aggrmerge=0/0, aggrticks=0/0, aggrin_queue=0, aggrutil=0.00%

If you look at the disk stats, it also shows a considerable amount of
reads. So I'm guessing that you need pre_read=1 to get the same sort of
results.

-- 
Jens Axboe


  parent reply	other threads:[~2009-07-18 14:39 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-07-16 13:40 fio mmap writes much slower than default writes Richard Kennedy
2009-07-18  6:18 ` Jens Axboe
2009-07-18 13:58   ` Richard Kennedy
2009-07-18 14:20     ` Jens Axboe
2009-07-18 14:39     ` Jens Axboe [this message]
2009-07-18 14:50       ` Richard Kennedy

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