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From: Jens Axboe <jens.axboe@oracle.com>
To: "Vitaly V. Bursov" <vitalyb@telenet.dn.ua>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Slow file transfer speeds with CFQ IO scheduler in some cases
Date: Mon, 10 Nov 2008 11:44:24 +0100	[thread overview]
Message-ID: <20081110104423.GA26778@kernel.dk> (raw)
In-Reply-To: <4917263D.2090904@telenet.dn.ua>

On Sun, Nov 09 2008, Vitaly V. Bursov wrote:
> Hello,
> 
> I'm building small server system with openvz kernel and have ran into
> some IO performance problems. Reading a single file via NFS delivers
> around 9 MB/s over gigabit network, but while reading, say, 2 different
> or same file 2 times at the same time I get >60MB/s.
> 
> Changing IO scheduler to deadline or anticipatory fixes problem.
> 
> Tested kernels:
>   OpenVZ RHEL5 028stab059.3 (9 MB/s with HZ=100, 20MB/s with HZ=1000
>                  fast local reads)
>   Vanilla 2.6.27.5 (40 MB/s with HZ=100, slow local reads)
> 
> Vanilla performs better in worst case but I believe 40 is still low
> concerning test results below.

Can you check with this patch applied?

http://bugzilla.kernel.org/attachment.cgi?id=18473&action=view

-- 
Jens Axboe


  parent reply	other threads:[~2008-11-10 10:46 UTC|newest]

Thread overview: 70+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-11-09 18:04 Slow file transfer speeds with CFQ IO scheduler in some cases Vitaly V. Bursov
2008-11-09 18:30 ` Alexey Dobriyan
2008-11-09 18:32   ` Vitaly V. Bursov
2008-11-10 10:44 ` Jens Axboe [this message]
2008-11-10 13:51   ` Jeff Moyer
2008-11-10 13:56     ` Jens Axboe
2008-11-10 17:16       ` Vitaly V. Bursov
2008-11-10 17:35         ` Jens Axboe
2008-11-10 18:27           ` Vitaly V. Bursov
2008-11-10 18:29             ` Jens Axboe
2008-11-10 18:39               ` Jeff Moyer
2008-11-10 18:42               ` Jens Axboe
2008-11-10 21:51             ` Jeff Moyer
2008-11-11  9:34               ` Jens Axboe
2008-11-11  9:35                 ` Jens Axboe
2008-11-11 11:52                   ` Jens Axboe
2008-11-11 16:48                     ` Jeff Moyer
2008-11-11 18:08                       ` Jens Axboe
2008-11-11 16:53                     ` Vitaly V. Bursov
2008-11-11 18:06                       ` Jens Axboe
2008-11-11 19:36                         ` Jeff Moyer
2008-11-11 21:41                           ` Jeff Layton
2008-11-11 21:59                             ` Jeff Layton
2008-11-12 12:20                               ` Jens Axboe
2008-11-12 12:45                                 ` Jeff Layton
2008-11-12 12:54                                   ` Christoph Hellwig
2008-11-11 19:42                         ` Vitaly V. Bursov
2008-11-12 18:32       ` Jeff Moyer
2008-11-12 19:02         ` Jens Axboe
2008-11-13  8:51           ` Wu Fengguang
2008-11-13  8:54             ` Jens Axboe
2008-11-14  1:36               ` Wu Fengguang
2008-11-25 11:02                 ` Vladislav Bolkhovitin
2008-11-25 11:25                   ` Wu Fengguang
2008-11-25 15:21                   ` Jeff Moyer
2008-11-25 16:17                     ` Vladislav Bolkhovitin
2008-11-13 18:46             ` Vitaly V. Bursov
2008-11-25 10:59             ` Vladislav Bolkhovitin
2008-11-25 11:30               ` Wu Fengguang
2008-11-25 11:41                 ` Vladislav Bolkhovitin
2008-11-25 11:49                   ` Wu Fengguang
2008-11-25 12:03                     ` Vladislav Bolkhovitin
2008-11-25 12:09                       ` Vladislav Bolkhovitin
2008-11-25 12:15                         ` Wu Fengguang
2008-11-27 17:46                           ` Vladislav Bolkhovitin
2008-11-28  0:48                             ` Wu Fengguang
2009-02-12 18:35                               ` Vladislav Bolkhovitin
2009-02-13  1:57                                 ` Wu Fengguang
2009-02-13 20:08                                   ` Vladislav Bolkhovitin
2009-02-16  2:34                                     ` Wu Fengguang
2009-02-17 19:03                                       ` Vladislav Bolkhovitin
2009-02-18 18:14                                         ` Vladislav Bolkhovitin
2009-02-19  1:35                                         ` Wu Fengguang
2009-02-17 19:01                                   ` Vladislav Bolkhovitin
2009-02-19  2:05                                     ` Wu Fengguang
2009-03-19 17:44                                       ` Vladislav Bolkhovitin
2009-03-20  8:53                                         ` Vladislav Bolkhovitin
2009-03-23  1:42                                         ` Wu Fengguang
2009-04-21 18:18                                           ` Vladislav Bolkhovitin
2009-04-24  8:43                                             ` Wu Fengguang
2009-05-12 18:13                                               ` Vladislav Bolkhovitin
2009-02-17 19:01                                 ` Vladislav Bolkhovitin
2009-02-19  1:38                                   ` Wu Fengguang
2008-11-24 15:33           ` Jeff Moyer
2008-11-24 18:13             ` Jens Axboe
2008-11-24 18:50               ` Jeff Moyer
2008-11-24 18:51                 ` Jens Axboe
2008-11-13  6:54         ` Vitaly V. Bursov
2008-11-13 14:32           ` Jeff Moyer
2008-11-13 18:33             ` Vitaly V. Bursov

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