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Subject: Re: 2.4.17 absurd number of context switches
To: jwb@saturn5.com (Jeffrey W. Baker)
Date: Fri, 28 Dec 2001 17:02:09 +0000 (GMT)
Cc: linux-kernel@vger.kernel.org
In-Reply-To: <Pine.LNX.4.33.0112280824550.23655-100000@windmill.gghcwest.com> from "Jeffrey W. Baker" at Dec 28, 2001 08:35:50 AM
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From: Alan Cox <alan@lxorguk.ukuu.org.uk>
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> Check out those figures for context switches!  30,000 switches per second
> with only three runnable processes and practically no block I/O seems
> quite high to me.  You can also see that the system is spending half its
..
> Is this a scheduler worst-case, something to be expected, or something I
> can work around?

The scheduler is _good_ at the three process case. Run some straces it looks
more like postgres is doing wacky yield based locks.

Alan
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