From: Zan Lynx <zlynx@acm.org>
To: Prakash Punnoor <prakash@punnoor.de>
Cc: Jan Engelhardt <jengelh@computergmbh.de>,
Lukas Hejtmanek <xhejtman@ics.muni.cz>,
linux-kernel@vger.kernel.org
Subject: Re: Disk schedulers
Date: Fri, 15 Feb 2008 10:11:26 -0700 [thread overview]
Message-ID: <1203095486.6663.12.camel@localhost> (raw)
In-Reply-To: <200802151557.59082.prakash@punnoor.de>
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On Fri, 2008-02-15 at 15:57 +0100, Prakash Punnoor wrote:
> On the day of Friday 15 February 2008 Jan Engelhardt hast written:
> > On Feb 14 2008 17:21, Lukas Hejtmanek wrote:
> > >Hello,
> > >
> > >whom should I blame about disk schedulers?
> >
> > Also consider
> > - DMA (e.g. only UDMA2 selected)
> > - aging disk
>
> Nope, I also reported this problem _years_ ago, but till now much hasn't
> changed. Large writes lead to read starvation.
Yes, I see this often myself. It's like the disk IO queue (I set mine
to 1024) fills up, and pdflush and friends can stuff write requests into
it much more quickly than any other programs can provide read requests.
CFQ and ionice work very well up until iostat shows average IO queuing
above 1024 (where I set the queue number).
--
Zan Lynx <zlynx@acm.org>
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next prev parent reply other threads:[~2008-02-15 17:11 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-02-14 16:21 Disk schedulers Lukas Hejtmanek
2008-02-15 0:02 ` Tejun Heo
2008-02-15 10:09 ` Lukas Hejtmanek
2008-02-15 14:42 ` Jan Engelhardt
2008-02-15 14:57 ` Prakash Punnoor
2008-02-15 17:11 ` Zan Lynx [this message]
2008-02-15 21:32 ` FD Cami
2008-02-16 16:13 ` Lukas Hejtmanek
2008-02-20 17:04 ` Zdenek Kabelac
2008-02-15 15:59 ` Lukas Hejtmanek
2008-02-15 16:22 ` Jeffrey E. Hundstad
2008-02-15 17:36 ` Roger Heflin
2008-02-15 17:24 ` Paulo Marques
2008-02-16 16:15 ` Lukas Hejtmanek
2008-02-16 17:20 ` Pavel Machek
2008-02-20 18:48 ` Lukas Hejtmanek
2008-02-21 23:50 ` Giuliano Pochini
2008-02-17 19:38 ` Linda Walsh
2008-02-28 17:14 ` Bill Davidsen
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