Re: SD scheduler testing hitch

From: Al Boldi
Date: Sun Apr 08 2007 - 14:31:41 EST


Mike Galbraith wrote:
> On Sat, 2007-04-07 at 19:17 +0200, Mike Galbraith wrote:
> > I lowered the time to 500us, and ran at nice -10.. it starves tenpercent
> > here every time. (ran as taskset -c 1 nice -n -10 ./fairtest) The
> > starving 10% duty cycle task has trouble getting 1% CPU.
>
> Hmm. Playing with it some more today, it still happens, but it's not
> very repeatable. Something is odd. I wonder if any SD using readers
> will try it.

Tried it on mainline 2.6.20.3.
It's not easily repeatable, but it's got the same problem.

top - 21:21:45 up 27 min, 0 users, load average: 0.80, 0.43, 0.20
Tasks: 45 total, 3 running, 42 sleeping, 0 stopped, 0 zombie
Cpu(s): 24.3% user, 0.5% system, 0.0% nice, 75.0% idle, 0.2% IO-wait
Mem: 499488k total, 27352k used, 472136k free, 1996k buffers
Swap: 1020088k total, 0k used, 1020088k free, 9160k cached

PID PR NI VIRT RES SHR SWAP nFLT nDRT WCHAN S %CPU TIME+ Command
688 25 0 1804 412 352 1392 0 0 rest_init R 94.7 2:37.01 fairtest
689 15 0 1804 264 204 1540 0 0 rest_init R 0.0 0:00.79 fairtest
1 15 0 1440 500 444 940 15 0 rest_init S 0.0 0:00.73 init


Thanks!

--
Al

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