Re: [patch] Re: scheduler oddity [bug?]

From: Mike Galbraith
Date: Mon Mar 09 2009 - 09:38:19 EST


On Mon, 2009-03-09 at 14:16 +0100, Mike Galbraith wrote:
> On Mon, 2009-03-09 at 12:04 +0100, Peter Zijlstra wrote:
>
> > OK, talked a bit with Ingo, the reason you're doing is that avg_overlap
> > can easily grow stale.. I can see that happen indeed.
> >
> > So the 'perfect' thing would be a task-runtime decay, barring that the
> > preemption thing seems a sane enough hart-beat of a task.
> >
> > How does the below look to you?
>
> Other than the fact that the test for sync reject is currently
> avg_overlap > sysctl_sched_migration_cost, looks fine to me. Having it
> capped at the boundary is probably the better way to go.

Heh, doesn't _quite_ work though. The little bugger now hovers just
under :-/

pipetest (5976, #threads: 1)
---------------------------------------------------------
se.exec_start : 150672.502691
se.vruntime : 94882.186606
se.sum_exec_runtime : 34875.797932
se.avg_overlap : 0.499993
nr_switches : 3680
nr_voluntary_switches : 0
nr_involuntary_switches : 3680
se.load.weight : 1024
policy : 0
prio : 120
clock-delta : 112

pipetest (5977, #threads: 1)
---------------------------------------------------------
se.exec_start : 150665.016951
se.vruntime : 94817.157909
se.sum_exec_runtime : 7069.323019
se.avg_overlap : 0.012718
nr_switches : 2931
nr_voluntary_switches : 2930
nr_involuntary_switches : 1
se.load.weight : 1024
policy : 0
prio : 120
clock-delta : 117


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