From: Arjan van de Ven <arjan@infradead.org>
To: Martin Lucina <mato@kotelna.sk>
Cc: Chris Mason <chris.mason@oracle.com>,
Andrew Morton <akpm@linux-foundation.org>,
Martin Sustrik <sustrik@fastmq.com>,
linux-kernel@vger.kernel.org, linux-aio@kvack.org
Subject: Re: Higher than expected disk write(2) latency
Date: Thu, 10 Jul 2008 07:01:51 -0700 [thread overview]
Message-ID: <20080710070151.5fccbbcf@infradead.org> (raw)
In-Reply-To: <20080710134144.GA31461@dezo.moloch.sk>
On Thu, 10 Jul 2008 15:41:46 +0200
Martin Lucina <mato@kotelna.sk> wrote:
> chris.mason@oracle.com said:
> > Is NCQ enabled on the drive? The basic way to fix this is to have
> > multiple requests in flight, which isn't going to happen on sata
> > with the cache off and with ncq off.
>
> ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
> ata1.00: ATA-7: Hitachi HDS721616PLA380, P22OAB3A, max UDMA/133
> ata1.00: 321672960 sectors, multi 0: LBA48 NCQ (depth 31/32)
> ata1.00: configured for UDMA/133
>
> I'm assuming the above indicates NCQ is enabled.
>
> We'll try running the tests tomorrow with different i/o schedulers and
> report back.
another thing to try is using AHCI mode instead; AHCI tends to be
higher performance
(and.. for fun try to run latencytop during a run, to see if maybe
there are unsuspected delay causes)
--
If you want to reach me at my work email, use arjan@linux.intel.com
For development, discussion and tips for power savings,
visit http://www.lesswatts.org
next prev parent reply other threads:[~2008-07-10 14:02 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-06-28 12:11 Higher than expected disk write(2) latency Martin Lucina
2008-06-28 13:11 ` Roger Heflin
2008-06-30 18:10 ` Martin Sustrik
2008-06-30 19:02 ` Roger Heflin
2008-06-30 22:20 ` Martin Sustrik
2008-07-01 0:11 ` Bernd Eckenfels
2008-07-02 16:48 ` Martin Sustrik
2008-07-02 18:15 ` Jeff Moyer
2008-07-02 18:20 ` Martin Sustrik
2008-07-04 3:16 ` David Dillow
2008-07-02 21:33 ` Roger Heflin
2008-06-28 14:47 ` David Newall
2008-06-29 11:34 ` Martin Sustrik
2008-07-10 5:27 ` Andrew Morton
2008-07-10 8:12 ` Martin Sustrik
2008-07-10 8:14 ` Andrew Morton
2008-07-10 13:29 ` Chris Mason
2008-07-10 13:41 ` Martin Lucina
2008-07-10 14:01 ` Arjan van de Ven [this message]
2008-07-10 14:18 ` Chris Mason
2008-07-10 8:31 ` Alan Cox
2008-07-10 13:17 ` Martin Sustrik
2008-07-10 13:18 ` Andrew Morton
2008-07-11 15:17 ` Martin Sustrik
[not found] <fa.OZMA74BZPX46rhnjz1am4hB786M@ifi.uio.no>
2008-06-30 6:41 ` Robert Hancock
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