Re: 2.5.74-mm1

From: Daniel Phillips (phillips@arcor.de)
Date: Sun Jul 06 2003 - 08:54:48 EST


On Sunday 06 July 2003 04:21, Davide Libenzi wrote:
> On Sun, 6 Jul 2003, Daniel Phillips wrote:
> > On Sunday 06 July 2003 03:28, Jamie Lokier wrote:
> > > Your last point is most important. At the moment, a SCHED_RR process
> > > with a bug will basically lock up the machine, which is totally
> > > inappropriate for a user app.
> >
> > How does the lockup come about? As defined, a single SCHED_RR process
> > could lock up only its own slice of CPU, as far as I can see.
>
> They're de-queued and re-queue in the active array w/out having dynamic
> priority adjustment (like POSIX states). This means that any task with
> lower priority will starve if the RR task will not release the CPU.

OK, I see, I didn't pay close enough attention to the "it will be put at the
end of the list _for its priority_" part.

So SCHED_RR is broken by design, too bad. Now, how would SCHED_RR_NOTBROKEN
work?

Regards,

Daniel

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