Re: Bad interactive behaviour in 2.5.65-66 (sched.c)

[Mike Galbraith]

At 08:35 AM 3/31/2003 +0200, Jens Axboe wrote:
>On Mon, Mar 31 2003, Mike Galbraith wrote:
> > At 07:06 AM 3/31/2003 +1000, Con Kolivas wrote:
> > >On Mon, 31 Mar 2003 00:14, Jens Axboe wrote:
> > >> On Sat, Mar 29 2003, Robert Love wrote:
> > >> > On Sat, 2003-03-29 at 21:33, Con Kolivas wrote:
> > >> > > Are you sure this should be called a bug? Basically X is an
> > >interactive
> > >> > > process. If it now is "interactive for a priority -10 process" then
> > >it
> > >> > > should be hogging the cpu time no? The priority -10 was a workaround
> > >> > > for lack of interactivity estimation on the old scheduler.
> > >> >
> > >> > Well, I do not necessarily think that renicing X is the problem.  Just
> > >> > an idea.
> > >>
> > >> I see the exact same behaviour here (systems appears fine, cpu intensive
> > >> app running, attempting to start anything _new_ stalls for ages), and I
> > >> definitely don't play X renice tricks.
> > >>
> > >> It basically made 2.5 unusable here, waiting minutes for an ls to even
> > >> start displaying _anything_ is totally unacceptable.
> > >
> > >I guess I should have trusted my own benchmark that was showing this was
> > >worse
> > >for system responsiveness.
> >
> > I don't think it's really bad for system responsiveness.  I think the
>
>What drugs are you on? 2.5.65/66 is the worst interactive kernel I've
>ever used, it would be _embarassing_ to release a 2.6-test with such a
>rudimentary flaw in it. IOW, a big show stopper.

It's only horrible when you trigger the problems, otherwise it's wonderful.

> > problem is just that the sample is too small.  The proof is that simply
> > doing sleep_time %= HZ cures most of my woes.  WRT contest and it's
>
>Irk, that sounds like a really ugly bandaid.

Nope, it's a really ugly _tourniquet_ ;-)

>I'm wondering why the scheduler guys aren't all over this problem,
>getting it fixed.

I think they are.

         -Mike