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From: Martin Knoblauch <spamtrap@knobisoft.de>
To: Jesper Juhl <jesper.juhl@gmail.com>, Robert Hancock <hancockr@shaw.ca>
Cc: knobi@knobisoft.de, linux-kernel@vger.kernel.org
Subject: Re: Understanding I/O behaviour
Date: Fri, 6 Jul 2007 00:54:13 -0700 (PDT)	[thread overview]
Message-ID: <684951.37870.qm@web32606.mail.mud.yahoo.com> (raw)
In-Reply-To: <9a8748490707051653q6e1b6bf3g9a3d6edf213867d9@mail.gmail.com>


--- Jesper Juhl <jesper.juhl@gmail.com> wrote:

> On 06/07/07, Robert Hancock <hancockr@shaw.ca> wrote:
> [snip]
> >
> > Try playing with reducing /proc/sys/vm/dirty_ratio and see how that
> > helps. This workload will fill up memory with dirty data very
> quickly,
> > and it seems like system responsiveness often goes down the toilet
> when
> > this happens and the system is going crazy trying to write it all
> out.
> >
> 
> Perhaps trying out a different elevator would also be worthwhile.
> 

 AS seems to be the best one (NOOP and DeadLine seem to be equally OK).
CFQ gives less (about 10-15%) throughput except for the kernel with the
cfs cpu scheduler, where CFQ is on par with the other IO schedulers.

Thanks
Martin

------------------------------------------------------
Martin Knoblauch
email: k n o b i AT knobisoft DOT de
www:   http://www.knobisoft.de

  reply	other threads:[~2007-07-06  7:54 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <fa.gAvf+r9fiPwNwNVqahYy5u1/Is0@ifi.uio.no>
2007-07-05 23:47 ` Understanding I/O behaviour Robert Hancock
2007-07-05 23:53   ` Jesper Juhl
2007-07-06  7:54     ` Martin Knoblauch [this message]
2007-07-06 10:15       ` Brice Figureau
2007-07-06 10:11   ` Martin Knoblauch
2007-07-07 13:23     ` Leroy van Logchem
2007-07-06 14:25 Daniel J Blueman
2007-07-06 15:17 ` Martin Knoblauch
2007-07-06 15:44   ` Daniel J Blueman
  -- strict thread matches above, loose matches on Subject: below --
2007-07-06 12:44 Martin Knoblauch
2007-07-06 11:03 Martin Knoblauch
2007-07-06 10:18 Martin Knoblauch
2007-07-05 15:40 Martin Knoblauch
2007-07-05 18:15 ` Andrew Lyon
2007-07-05 20:22 ` Jesper Juhl
2007-07-08 21:28   ` Jesper Juhl
2007-07-09  8:47     ` Martin Knoblauch

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