Re: I/O problems in 2.4.19/2.4.20/2.4.21-rc3

From: William Lee Irwin III (wli@holomorphy.com)
Date: Sat May 24 2003 - 23:32:29 EST


On Sun, May 25, 2003 at 11:27:20AM +1000, Con Kolivas wrote:
> Even though you're not Marc I do agree with you. The problem is well
> described as either poor interactivity (the window wiggle test) or
> starvation in the presence of certain scheduler hogs (for whatever
> reason) since the interactivity patch from mingo. Dropping the max
> timeslice is a bandaid but destroys priority based timeslice
> scheduling. Dropping the min timeslice will bring this back, but at
> some point the timeslice will be so low that low priority cpu
> intensive tasks will spend most of their time cache trashing.

The fact that it's a "bandaid" and that it "destroys priority-based
timeslice scheduling" makes it a shenanigan. If you're having problems
solved by capping timeslices, you have someone's timeslice and/or
priority growing too large for some reason.

It'd be far better to help figure out what went wrong.


-- wli
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