All of lore.kernel.org
 help / color / mirror / Atom feed
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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20160212093501.16002.32635.stgit@Solace.station \
    --to=dario.faggioli@citrix.com \
    --cc=Andrew.Cooper3@citrix.com \
    --cc=JBeulich@suse.com \
    --cc=Marcus.Granado@eu.citrix.com \
    --cc=george.dunlap@eu.citrix.com \
    --cc=malcolm.crossley@citrix.com \
    --cc=xen-devel@lists.xenproject.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.