Re: BFS vs. mainline scheduler benchmarks and measurements

From: Jens Axboe
Date: Thu Sep 10 2009 - 07:09:42 EST


On Thu, Sep 10 2009, Mike Galbraith wrote:
> On Thu, 2009-09-10 at 12:28 +0200, Jens Axboe wrote:
>
> > No difference. Then I tried switching NO_NEW_FAIR_SLEEPERS on, and then
> > I get:
> >
> > Performance counter stats for 'xmodmap .xmodmap-carl':
> >
> > 9.009137 task-clock-msecs # 0.447 CPUs
> > 18 context-switches # 0.002 M/sec
> > 1 CPU-migrations # 0.000 M/sec
> > 315 page-faults # 0.035 M/sec
> > <not counted> cycles
> > <not counted> instructions
> > <not counted> cache-references
> > <not counted> cache-misses
> >
> > 0.020167093 seconds time elapsed
> >
> > Woot!
>
> Something is very seriously hosed on that box... clock?

model name : Genuine Intel(R) CPU T2400 @ 1.83GHz

Throttles down to 1.00GHz when idle.

> Can you turn it back on, and do..

I guess you mean turn NEW_FAIR_SLEEPERS back on, correct?

> while sleep .1; do cat /proc/sched_debug >> foo; done
> ..on one core, and (quickly;) xmodmap .xmodmap-carl, then send me a few
> seconds worth (gzipped up) to eyeball?

Attached.

--
Jens Axboe

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