Re: [PATCH v4] sched: automated per session task groups

Peter Zijlstra
2010-11-29T11:53:04Z

On Sun, 2010-11-28 at 21:18 +0100, Ingo Molnar wrote:
> * Linus Torvalds <torvalds@linux-foundation.org> wrote:
>
> > On Sun, Nov 28, 2010 at 6:24 AM, Mike Galbraith <efault@gmx.de> wrote:
> > >
> > > Something else is seriously wrong though. 36.1 with attached (plus
> > > sched, cgroup: Fixup broken cgroup movement) works a treat, whereas
> > > 37.git and tip with fixlet below both suck rocks. With a make -j40
> > > running, wakeup-latency is showing latencies of >100ms, amarok skips,
> > > mouse lurches badly.. generally horrid. Something went south.
> >
> > Can you test -rc3? Is that still ok? And are you perhaps using
> > Nouveau? There's a report of some graphics (?) regression since -rc3
> > about bad desktop performance:
> >
> > https://bugzilla.kernel.org/show_bug.cgi?id=23912
> >
> > but it doesn't have any more information yet (so if -rc3 _is_ good for
> > you, and you can add anything to that report, it would be good. The
> > original reporter is hopefully bisecting it now)
>
> Mike, the last pure -rc3 -tip commit is 92c883adf03b - you could try to check that
> out too: it has most of the current sched/core commits, but has none of the post-rc3
> DRM changes.

Well we totally re-wrote the cgroup load-balancer in -tip. The thing
currently in -linus is a utter crap because its very strongly serialized
across all cores (some people spend like 25% of their time in there).