Messages in this thread | | | Subject | Re: [sched-devel, patch-rfc] rework of "prioritize non-migratabletasks over migratable ones" | From | Peter Zijlstra <> | Date | Wed, 18 Jun 2008 12:47:44 +0200 |
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On Wed, 2008-06-18 at 12:39 +0200, Ingo Molnar wrote: > * Gregory Haskins <ghaskins@novell.com> wrote: > > > >>> On Mon, Jun 16, 2008 at 3:17 PM, in message > > <1213643862.16944.142.camel@twins>, Peter Zijlstra <a.p.zijlstra@chello.nl> > > 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.
Sadly, some people do read it like that.
> so ... lets apply Dmitry's nice simplification, hm?
As long as it doesn't wreck the per RQ queue model and only affects the SMP interaction that would be acceptable I guess.
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