Re: Strange load issues with 2.5.69/70 in both -mm and -bk trees.

From: William Lee Irwin III (
Date: Mon Jun 02 2003 - 10:53:45 EST

On Mon, Jun 02, 2003 at 11:47:56AM -0400, Tom Sightler wrote:
> In trying to figure out why this might be worse under 2.5 I took some
> simple vmstat numbers under 2.4 and 2.5, this biggest difference is the
> number of context switches. Under 2.4, with the page loaded, but
> otherwise idle, the system averages around 700/sec, and when I mouse
> around the page I get 2000-3000/sec.
> However, under 2.5, as I reported previously, I get 2000/sec all the
> time, and 3000-4000 as I mouse around the page.
> Would this be expected behavior? Does 2.5 do something that would cause
> more context switches that 2.4? I have no idea if this would have any
> impact at all, but it was the only difference I could observe in my
> fairly simple testing of the two kernels.

A quick patch to register profile hit counts for codepaths calling
schedule() and/or yield() appears to be in order for such occasions.

-- wli
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