From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dario Faggioli <dario.faggioli@citrix.com>
Subject: Re: schedulers and topology exposing questions
Date: Thu, 28 Jan 2016 09:55:45 +0000
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To: George Dunlap <george.dunlap@citrix.com>, Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Elena Ufimtseva <elena.ufimtseva@oracle.com>, george.dunlap@eu.citrix.com, joao.m.martins@oracle.com, boris.ostrovsky@oracle.com, xen-devel@lists.xen.org
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On Wed, 2016-01-27 at 15:53 +0000, George Dunlap wrote:
> On 27/01/16 15:27, Konrad Rzeszutek Wilk wrote:
> >=C2=A0
> > So Elena started looking at the CPU bound and seeing how Xen
> > behaves then
> > and if we can improve the floating situation as she saw some
> > abnormal
> > behavious.
>=20
> OK -- if the focus was on the two cases where the Xen credit1
> scheduler
> (apparently) co-located two cpu-burning vcpus on sibling threads,
> then
> yeah, that's behavior we should probably try to get to the bottom of.
>=20
Well, let's see the trace.=C2=A0

In any case, I'm up to trying hooking the SMT load balancer in
runq_tickle (which would mean doing it upon every vcpus wakeup).

My gut feeling is that the overhead my outwieght the benefit, and that
it will actually reveal useful only in a minority of the
cases/workloads, but it's maybe worth a try.

Regards,
Dario
--=20
<<This happens because I choose it to happen!>> (Raistlin Majere)
-----------------------------------------------------------------
Dario Faggioli, Ph.D, http://about.me/dario.faggioli
Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK)


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