From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753738AbbFVQaN (ORCPT ); Mon, 22 Jun 2015 12:30:13 -0400 Received: from e28smtp01.in.ibm.com ([122.248.162.1]:56544 "EHLO e28smtp01.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751172AbbFVQaF (ORCPT ); Mon, 22 Jun 2015 12:30:05 -0400 X-Helo: d28dlp02.in.ibm.com X-MailFrom: srikar@linux.vnet.ibm.com X-RcptTo: linux-kernel@vger.kernel.org Date: Mon, 22 Jun 2015 21:59:58 +0530 From: Srikar Dronamraju To: Rik van Riel Cc: Ingo Molnar , Peter Zijlstra , linux-kernel@vger.kernel.org, Mel Gorman Subject: Re: [PATCH v2 2/4] sched:Consider imbalance_pct when comparing loads in numa_has_capacity Message-ID: <20150622162958.GB32412@linux.vnet.ibm.com> Reply-To: Srikar Dronamraju References: <1434455762-30857-1-git-send-email-srikar@linux.vnet.ibm.com> <1434455762-30857-3-git-send-email-srikar@linux.vnet.ibm.com> <55803511.1060601@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <55803511.1060601@redhat.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15062216-4790-0000-0000-000008D54CFE Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Rik van Riel [2015-06-16 10:39:13]: > On 06/16/2015 07:56 AM, Srikar Dronamraju wrote: > > This is consistent with all other load balancing instances where we > > absorb unfairness upto env->imbalance_pct. Absorbing unfairness upto > > env->imbalance_pct allows to pull and retain task to their preferred > > nodes. > > > > Signed-off-by: Srikar Dronamraju > > How does this work with other workloads, eg. > single instance SPECjbb2005, or two SPECjbb2005 > instances on a four node system? > > Is the load still balanced evenly between nodes > with this patch? > Yes, I have looked at mpstat logs while running SPECjbb2005 for 1JVMper System, 2 JVMs per System and 4 JVMs per System and observed that the load spreading was similar with and without this patch. Also I have visualized using htop when running 0.5X (i.e 48 threads on 96 cpu system) cpu stress workloads to see that the spread is similar before and after the patch. Please let me know if there are any better ways to observe the spread. In a slightly loaded or less loaded system, the chance of migrating threads to their home node by way of calling migrate_task_to and migrate_swap might be curtailed without this patch. i.e 2 process each having N/2 threads may converge slower without this change. -- Thanks and Regards Srikar Dronamraju -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in Please read the FAQ at http://www.tux.org/lkml/