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From: Dario Faggioli <dario.faggioli@citrix.com>
To: xen-devel@lists.xenproject.org
Cc: George Dunlap <george.dunlap@eu.citrix.com>,
	Marcus Granado <Marcus.Granado@eu.citrix.com>,
	Malcolm Crossley <malcolm.crossley@citrix.com>,
	Jan Beulich <JBeulich@suse.com>,
	Andrew Cooper <Andrew.Cooper3@citrix.com>
Subject: [PATCH 0/2] xen: sched: Credit1 shouldn't boost vcpus being migrated.
Date: Fri, 12 Feb 2016 10:36:48 +0100	[thread overview]
Message-ID: <20160212093501.16002.32635.stgit@Solace.station> (raw)

Hi again,

Here it comes v2, redone following Jan's suggestion, which allowed to get rid
of patch 2, and do everything in sched_credit.c.

So, in summary, because of the fact that vcpu_migrate() forces the vcpus into a
sleep+wakeup cycle, vcpus being migrated to a new pcpu, were also being granted
BOOST priority, inside Credit1, and that is not correct.

More info on v1's cover letter, which is here:

  http://lists.xenproject.org/archives/html/xen-devel/2016-02/msg01620.html

I re-run the same set of benchmarks described in v1, and the result for this
rework of the series are basically the same as there.

Thanks and Regards,
Dario
---
Dario Faggioli (2):
      xen: credit1: trace vCPU boost/unboost
      xen: credit1: avoid boosting vCPUs being "just" migrated

 xen/common/sched_credit.c    |   34 ++++++++++++++++++++++++++++++----
 xen/include/xen/perfc_defn.h |    1 +
 2 files changed, 31 insertions(+), 4 deletions(-)
--
<<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)

             reply	other threads:[~2016-02-12  9:36 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-12  9:36 Dario Faggioli [this message]
2016-02-12  9:36 ` [PATCH v2 1/2] xen: credit1: trace vCPU boost/unboost Dario Faggioli
2016-02-12  9:37 ` [PATCH v2 2/2] xen: credit1: avoid boosting vCPUs being "just" migrated Dario Faggioli
2016-02-12  9:50   ` Jan Beulich
2016-02-12 10:50     ` Dario Faggioli
2016-02-12 14:16       ` Dario Faggioli

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