SMP Scheduling

Peter Waltenberg (peterw@dascom.com)
Mon, 09 Aug 1999 08:59:30 +1000 (EST)


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 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.

I know this has been reported before, and plausible explanations have been
offered. However plausible isn't the same as "correct" and this does seem to
be a symptom of a real problem, or at least a real change in behaviour.

Peter

----------------------------------
E-Mail: Peter Waltenberg <peterw@surf.dascom.com>
Date: 09-Aug-99
Time: 08:45:38

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