Re: bug in sched.c:activate_task()

[Peter Williams]

Con Kolivas wrote:
> Chen, Kenneth W writes:
>
> > Update p->timestamp to "now" in activate_task() doesn't look right
> > to me at all.  p->timestamp records last time it was running on a
> > cpu.  activate_task shouldn't update that variable when it queues
> > a task on the runqueue.
> >
> > This bug (and combined with others) triggers improper load balancing.
>
>
> The updated timestamp was placed there by Ingo to detect on-runqueue 
> time. If it is being used for load balancing then it is being used in 
> error.

The ZAPHOD scheduler (being trialled in 2.6.9-rc3-mm2) uses its own time 
stamp so as not to interfere with the use of timestamp by load balancing 
code so it should be OK to delete this line form activate_task() in 
2.6.9-rc3-mm2 without effecting ZAPHOD.

Peter
--
Peter Williams                                   pwil3058@xxxxxxxxxxxxxx

"Learning, n. The kind of ignorance distinguishing the studious."
 -- Ambrose Bierce
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