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From: Mike Fedyk <mfedyk@matchmail.com>
To: Jamie Lokier <jamie@shareable.org>
Cc: Denis Vlasenko <vda@port.imtp.ilyichevsk.odessa.ua>,
	Sergey Spiridonov <spiridonov@gamic.com>,
	linux-kernel@vger.kernel.org
Subject: Re: how to turn off, or to clear read cache?
Date: Wed, 20 Aug 2003 15:52:00 -0700	[thread overview]
Message-ID: <20030820225200.GB1040@matchmail.com> (raw)
In-Reply-To: <20030820224628.GA24639@mail.jlokier.co.uk>

On Wed, Aug 20, 2003 at 11:46:28PM +0100, Jamie Lokier wrote:
> Denis Vlasenko wrote:
> > On 20 August 2003 14:52, Sergey Spiridonov wrote:
> > > I need to make some performance tests. I need to switch off or to clear 
> > > read cache, so that consequent reading of the same file will take the 
> > > same amount of time.
> > 
> > umount/mount cycle will do it, as well as intentional OOMing the box
> > (from non-root account please;)
> 
> umount/mount is impractical when you're testing performance on a big
> filesystem, which is always being used (e.g. /home).
> 
> I'm fairly sure that -o remount used to have this side effect, in fact
> I used it quite a lot for that purpose, so it should be possible to
> make it work again, or add a -o flushcache option.

Won't that hold a lot of locks, and possibly pause the system until the
flushing is complete?  Hopefully, in 2.6 this doesn't call lock_kernel...

  reply	other threads:[~2003-08-20 22:52 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-08-20 11:52 how to turn off, or to clear read cache? Sergey Spiridonov
2003-08-20 12:30 ` Måns Rullgård
2003-08-20 13:11 ` Denis Vlasenko
2003-08-20 14:30   ` Sergey Spiridonov
2003-08-20 22:46   ` Jamie Lokier
2003-08-20 22:52     ` Mike Fedyk [this message]
  -- strict thread matches above, loose matches on Subject: below --
2003-08-20 13:22 John Bradford
2003-08-20 13:23 ` Sergey Spiridonov
2003-08-20 13:31   ` Måns Rullgård
2003-08-20 16:49     ` Luciano Miguel Ferreira Rocha
2003-08-20 16:57       ` Måns Rullgård
2003-08-20 17:17         ` Jeff Garzik
2003-08-20 17:28           ` Måns Rullgård
     [not found] <mzNF.3z3.47@gated-at.bofh.it>
     [not found] ` <mB2M.4Jv.35@gated-at.bofh.it>
     [not found]   ` <mCi4.5Kq.3@gated-at.bofh.it>
2003-08-21 10:01     ` Ihar 'Philips' Filipau

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