Re: SMP Scheduling

Andreas Bombe (andreas.bombe@munich.netsurf.de)
Mon, 9 Aug 1999 19:34:20 +0200

On Mon, Aug 09, 1999 at 08:59:30AM +1000, Peter Waltenberg wrote:
> I also have a dual CPU machine.
>
> Under 2.0 if you ran a CPU hog it'd pretty well stick to one CPU.
>
> I.e. if you had xosview running you'd see one CPU at 100%, the other mostly
> idle. If there was a load burst, it might move to the other CPU, but that was
> pretty unusual.
>
> Under 2.2 you see that one CPU hog hopping CPU's and at regular intervals.
> Using xosview to track load what you see is a picket fence effect.
> And there are more than "3 processes" running, more like 80 on my machine,
> so running xosview alone shouldn't be enough to force this to happen and if
> it were, the other processes should be introducing enough noise to make the
> CPU swapping more erratic.

This is a misunderstanding. When I said "running", I meant running as
opposed to sleeping. The dozens of sleeping processes everyone has on
their machine won't affect scheduling at all.

> This does seem to be "wrong", not so much that the process is changing CPU's,
> thats reasonable, but the fact that it's doing it with such regularity now.

Xosview runs with regularity and therefore makes X run with regularity.
There you are. Try changing the refresh rate of xosview and see what
happens. Try not to use X (eliminates one running task).

-- 
    Andreas E. Bombe <andreas.bombe@munich.netsurf.de>
    http://home.pages.de/~andreas.bombe/
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