From: Robert Hancock <hancockr@shaw.ca>
To: Marr <marr@flex.com>, linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: Drastic Slowdown of 'fseek()' Calls From 2.4 to 2.6 -- VMM Change?
Date: Fri, 24 Feb 2006 17:31:20 -0600 [thread overview]
Message-ID: <43FF9748.9010603@shaw.ca> (raw)
In-Reply-To: <5JRJO-6Al-7@gated-at.bofh.it>
Marr wrote:
> Clearly, the 2.4.31 results are speedy because the whole 4MB file has been
> cached.
I don't think this is clear at all. The entire file should always be
cached, not doing this would be insane.
> What I cannot figure out is this: what has changed in 2.6.x kernels to cause
> the performance to degrade so drastically?!?
fseek() is a C library call, not a system call itself - there may be
something that glibc is doing differently. Are you using the same glibc
version with both kernels?
Just from this program it could be something else entirely that explains
the difference in speed, like the random number generator..
--
Robert Hancock Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@nospamshaw.ca
Home Page: http://www.roberthancock.com/
next parent reply other threads:[~2006-02-24 23:32 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <5JRJO-6Al-7@gated-at.bofh.it>
2006-02-24 23:31 ` Robert Hancock [this message]
2006-02-24 20:22 Drastic Slowdown of 'fseek()' Calls From 2.4 to 2.6 -- VMM Change? Marr
2006-02-25 5:16 ` Andrew Morton
2006-02-26 13:07 ` Ingo Oeser
2006-02-26 13:50 ` Nick Piggin
2006-02-26 14:11 ` Arjan van de Ven
2006-02-27 20:52 ` Hans Reiser
2006-02-28 0:34 ` Nick Piggin
2006-02-28 18:42 ` Hans Reiser
2006-02-28 18:51 ` Hans Reiser
2006-02-27 20:24 ` Marr
2006-02-27 21:53 ` Hans Reiser
2006-02-28 0:03 ` Bill Davidsen
2006-02-28 18:38 ` Hans Reiser
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