Re: [PATCH] [request for inclusion] Realtime LSM

Chris Wright
2005-01-11T20:50:31Z

* Matt Mackall (mpm@selenic.com) wrote:
> On Tue, Jan 11, 2005 at 08:05:08AM -0500, Paul Davis wrote:
> > I am not sure what you mean here. I think we've established that
> > SCHED_OTHER cannot be made adequate for realtime audio work. Its
> > intended purpose (timesharing the machine in ways that should
> > generally benefit tasks that don't do a lot and/or are dominated by
> > user interaction, thus rendering the machine apparently responsive) is
> > really at odds with what we need.
>
> We have not established that at all. In principle, because SCHED_OTHER
> tasks running at full priority lie on the boundary between SCHED_OTHER
> and SCHED_FIFO, they can be made to run arbitrarily close to the
> performance of tasks in SCHED_FIFO. With the upside that they won't be
> able to deadlock the machine.

I don't think they lie quite so neatly on this boundary. There's one
fundamental difference which is how the dynamic priority is adjusted
which alters the basic preemptibility rules.

thanks,
-chris
--
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