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Date: Tue, 28 Aug 2001 12:46:43 +0400
From: Hans Reiser <reiser@namesys.com>
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To: Mike Galbraith <mikeg@wen-online.de>
CC: Dieter N|tzel <Dieter.Nuetzel@hamburg.de>,
        Linux Kernel List <linux-kernel@vger.kernel.org>,
        Daniel Phillips <phillips@bonn-fries.net>,
        ReiserFS List <reiserfs-list@namesys.com>,
        "Gryaznova E." <grev@namesys.botik.ru>
Subject: Re: [reiserfs-list] Re: [resent PATCH] Re: very slow parallel read 
 performance
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Mike Galbraith wrote:
> 
> On Tue, 28 Aug 2001, Dieter N|tzel wrote:
> 
> > * readahead do not show dramatic differences
> > * killall -STOP kupdated DO
> >
> > Yes, I know it is dangerous to stop kupdated but my disk show heavy thrashing
> > (seeks like mad) since 2.4.7ac4. killall -STOP kupdated make it smooth and
> > fast, again.
> 
> Interesting.
> 
> A while back, I twiddled the flush logic in buffer.c a little and made
> kupdated only handle light flushing.. stay out of the way when bdflush
> is running.  This and some dynamic adjustment of bdflush flushsize and
> not stopping flushing right _at_ (biggie) the trigger level produced
> very interesting improvements.  (very marked reduction in system time
> for heavy IO jobs, and large improvement in file rewrite throughput)
> 
>         -Mike


Can you send us the patch, and Elena will run some tests on it?

Hans