Re: 2.5.74-mm1 and Con Kolivas' CPU scheduler work

Con Kolivas (kernel@kolivas.org)
Fri, 4 Jul 2003 12:29:06 +1000


On Fri, 4 Jul 2003 12:09, Tom Sightler wrote:
> On Thu, 2003-07-03 at 19:49, Con Kolivas wrote:
> > On Fri, 4 Jul 2003 02:36, ismail (cartman) donmez wrote:
> > > Hi,
> > >
> > > With Con Kolivas' cpu patch I got many slow downs. When I try to run
> > > CodeWeaver's CrossOver office box gets unresponsive at least for a one
> > > minute. While starting KDE ( when splash screen is running ) mouse gets
> > > too sluggish.
> >
> > While your wm starting if your mouse is sluggish it is probably not a big
> > problem, and it is part of something I'm already working on. The
> > codeweavers problem is impressive though; I don't have codeweavers and
> > have not seen anything like it. To get a full picture it would be helpful
> > if you could run top as root say reniced to -13 just so it doesn't miss
> > anything, and then start codeweavers, watch top and tell me what is
> > spinning away hogging the cpu.
>
> My guess is that he's seeing the same issue that I reported a few weeks
> ago with Crossover plugin. That report generated a fairly long thread
> and a lot of patches and testing, but little actual progress. Basically
> wine seems to have multiple threads and a client/server architecture and
> seems constantly spin on a pipe passing info back and forth to each
> other. It seems one thread gets all the attention and starves the
> others although the others are critical for the main process to actually
> make progress.
>
> I've been wanting to do some testing with your patches so I'll give them
> a spin tonight and see how this acts.

Ah yes I believe I know this issue. The problem is the parent spinning madly
waiting for the child and it is the parent that starves the child. While this
is not a fix, if you can reproduce the problem can you try changing
CHILD_PENALTY in kernel/sched.c from 50 to 100 and see if that makes the
problem go away? I mentioned this hidden in a thread a while ago, and am
trying to get a reasonable fix.

Con

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