On Fri, 10 Jun 2005 22:03, Con Kolivas wrote:
> On Fri, 10 Jun 2005 17:02, Ingo Molnar wrote:
> > * Martin J. Bligh <mbligh@mbligh.org> wrote:
> > > > I'm assuming it was the CPU scheduler patches.  There are 36 of them
> > > > ;)

> > So the 
> > candidates for the regression are:
> >
> >  sched-implement-nice-support-across-physical-cpus-on-smp.patch
> >  sched-change_prio_bias_only_if_queued.patch
> >  sched-account_rt_tasks_in_prio_bias.patch
> >  consolidate-preempt-options-into-kernel-kconfigpreempt.patch
> >  enable-preempt_bkl-on-preemptsmp-too.patch
> >  sched-tweak-idle-thread-setup-semantics.patch
> >  sched-voluntary-kernel-preemption.patch
> >  sched-smp-nice-bias-busy-queues-on-idle-rebalance.patch
> >  sched-task_noninteractive.patch
> >  sched-run-sched_normal-tasks-with-real-time-tasks-on-smt-siblings.patch

> These tend to run together so just try adding my four patches together. In
> retrospect I guess they're likely candidates because they also change the
> _ratio_ of balance which they should not so they are buggy as a group
> currently. Easy enough to fix but it will make it easy to pinpoint the
> problem if they're responsible.
>
> sched-implement-nice-support-across-physical-cpus-on-smp.patch
> sched-change_prio_bias_only_if_queued.patch
> sched-account_rt_tasks_in_prio_bias.patch
> sched-smp-nice-bias-busy-queues-on-idle-rebalance.patch

By the way it has already been decided to remove these patches from -mm 
pending the completion of current scheduler work. If they turn out to be 
responsible for this regression I apologise profusely :-|. 

It is clearer to me now that I have made a mistake with the priority biasing, 
and the following patch corrects it to the planned behaviour. This is 
academic at this stage as we won't be looking at this particular feature 
again in earnest until the other 32 scheduler patches (and any followups) go 
upstream. 

It's already known that schedstats data will be off without further code to 
understand smp nice as well (thanks Nick for pointing out the data)... more 
academic stuff but obviously something to consider when/if we get there.

Cheers,
Con