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Subject: Re: 2.4.17 absurd number of context switches
To: davidel@xmailserver.org (Davide Libenzi)
Date: Fri, 28 Dec 2001 17:37:01 +0000 (GMT)
Cc: alan@lxorguk.ukuu.org.uk (Alan Cox), jwb@saturn5.com (Jeffrey W. Baker),
        linux-kernel@vger.kernel.org
In-Reply-To: <Pine.LNX.4.40.0112280907060.1466-100000@blue1.dev.mcafeelabs.com> from "Davide Libenzi" at Dec 28, 2001 09:07:48 AM
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From: Alan Cox <alan@lxorguk.ukuu.org.uk>
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> > The scheduler is _good_ at the three process case. Run some straces it looks
> > more like postgres is doing wacky yield based locks.
> 
> The scheduler that Linus merged in 2.5.2-pre3 will solve the problem.

Looking at the postgres traces here it wont make any difference at all. Not
one iota. If I am reading it right I have processes each going
yield, yield, yield... so the kernel does just that (and indeed posix
semantics require that behaviour).

Alan
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