Re: Overscheduling DOES happen with high web server load.

Andrea Arcangeli (andrea@e-mind.com)
Fri, 7 May 1999 00:08:10 +0200 (CEST)


On Thu, 6 May 1999, Kurt Garloff wrote:

>On Thu, May 06, 1999 at 05:39:35PM +0200, Andrea Arcangeli wrote:
>> On Wed, 5 May 1999, Phillip Ezolt wrote:
>> >
>> >In doing some performance work with SPECWeb96 on ALpha/Linux with apache,
>> >it looks like "schedule" is the main bottleneck.
>>
>> Alt. Alpha uses HZ at 1024 so you get a scheduling rate by default 10
>> times higher than in all other archs.
>
>From what I understand, the scheduling is not caused by the timer but by
>blocking and woken processes.

Yes: reschedule_idle() is the culprit. I think we should simply use
goodness() in reschedule_idle() (instead of checking `->counter + 3 ...
->counter') to avoid overscheduling (or better "what I call
overscheduling" ;).

Andrea Arcangeli

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