From: Al Boldi <a1426z@gawab.com>
To: Ingo Molnar <mingo@elte.hu>
Subject: Re: [patch] CFS scheduler, -v7
Date: Thu, 3 May 2007 14:16:50 +0300
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References: <200704300820.49078.a1426z@gawab.com> <20070503074552.GA14960@elte.hu> <20070503080706.GA18427@elte.hu>
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Ingo Molnar wrote:
> * Ingo Molnar <mingo@elte.hu> wrote:
> > > [...] but there are still some nice issues.
> > >
> > > Try running 3 chew.c's, then renicing one to -10, starves others for
> > > some seconds while switching prio-level.  Now renice it back to 10,
> > > it starves for up to 45sec.
> >
> > ok - to make sure i understood you correctly: does this starvation
> > only occur right when you renice it (when switching prio levels), and
> > it gets rectified quickly once they get over a few reschedules?
>
> meanwhile i managed to reproduce it by following the exact steps you
> described, and i've fixed the bug in my tree. Can you confirm that the
> patch below fixes it for you too?

Seems like this fixed it.  But I can still see these awful latency blips in 
the presence of negatively niced chew.c at -10 and two chew.c's at nice 0.  
This gets really bad when sched_granularity_ns >= 5,000,000.


Thanks!

--
Al

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