Re: [announce] [patch] ultra-scalable O(1) SMP and UP scheduler

Andrea Arcangeli
2002-01-04T13:39:31Z

On Fri, Jan 04, 2002 at 03:33:19AM -0800, David Lang wrote:
> On Fri, 4 Jan 2002, Ingo Molnar wrote:
>
> > On Fri, 4 Jan 2002, David Lang wrote:
> >
> > > Ingo,
> > > back in the 2.4.4-2.4.5 days when we experimented with the
> > > child-runs-first scheduling patch we ran into quite a few programs that
> > > died or locked up due to this. (I had a couple myself and heard of others)
> >
> > hm, Andrea said that the only serious issue was in the sysvinit code,
> > which should be fixed in any recent distro. Andrea?
> >
>
> I remember running into problems with some user apps (not lockups, but the
> apps failed) on my 2x400MHz pentium box. I specificly remember the Citrix
> client hanging, but I think there were others as well.

those are broken apps that have to be fixed, they will eventually lockup
even without the patch. userspace can be preempted anytime.

> I'll try and get a chance to try your patch in the next couple days.
>
> David Lang
>
>
> > > try switching this back to the current behaviour and
> see if the > > lockups still happen.
> >
> > there must be some other bug as well, the child-runs-first scheduling can
> > cause lockups, but it shouldnt cause oopes.
> >
> > Ingo
> >

Andrea