Re: [sched-devel, patch-rfc] rework of "prioritizenon-migratabletasks over migratable ones"

From: Ingo Molnar
Date: Wed Jun 18 2008 - 06:39:50 EST



* Gregory Haskins <ghaskins@xxxxxxxxxx> wrote:

> >>> On Mon, Jun 16, 2008 at 3:17 PM, in message
> <1213643862.16944.142.camel@twins>, Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> wrote:
> > On Mon, 2008-06-16 at 19:59 +0200, Dmitry Adamushko wrote:
> >
> >> One way or another, we have different aritifacts (and mine have likely
> >> more) but conceptually, both "violates" POSIX if a strict round-robin
> >> scheduling is required.
> >
> > http://www.opengroup.org/onlinepubs/009695399/functions/xsh_chap02_08.html#t
> > ag_02_08_04_01
> >
> > Is quite strict on what FIFO should do, and I know of two points where
> > we deviate and should work to match.
>
> Thanks for the link, Peter. When you read that, its pretty clear that
> this whole concept violates the standard. Its probably best to just
> revert the patch and be done with it.

no, there's no spec violation here - the spec is silent on SMP issues.

the spec should not be read to force a global runqueue for RT tasks.
That would be silly beyond imagination.

so ... lets apply Dmitry's nice simplification, hm?

Ingo
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