From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: [PATCH 0/2] xen: sched: Credit1 shouldn't boost vcpus being migrated. Date: Fri, 12 Feb 2016 10:36:48 +0100 Message-ID: <20160212093501.16002.32635.stgit@Solace.station> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta14.messagelabs.com ([193.109.254.103]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1aUA9m-0002je-8y for xen-devel@lists.xenproject.org; Fri, 12 Feb 2016 09:36:54 +0000 Received: by mail-wm0-f67.google.com with SMTP id c200so1679166wme.0 for ; Fri, 12 Feb 2016 01:36:52 -0800 (PST) List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xenproject.org Cc: George Dunlap , Marcus Granado , Malcolm Crossley , Jan Beulich , Andrew Cooper List-Id: xen-devel@lists.xenproject.org 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(-) -- <> (Raistlin Majere) ------------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK)