From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965192AbaDKRYb (ORCPT ); Fri, 11 Apr 2014 13:24:31 -0400 Received: from shelob.surriel.com ([74.92.59.67]:48410 "EHLO shelob.surriel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754451AbaDKRY2 (ORCPT ); Fri, 11 Apr 2014 13:24:28 -0400 From: riel@redhat.com To: linux-kernel@vger.kernel.org Cc: mingo@kernel.org, peterz@infradead.org, chegu_vinod@hp.com, mgorman@suse.de Subject: [PATCH 0/3] sched,numa: reduce page migrations with pseudo-interleaving Date: Fri, 11 Apr 2014 13:00:26 -0400 Message-Id: <1397235629-16328-1-git-send-email-riel@redhat.com> X-Mailer: git-send-email 1.8.5.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The pseudo-interleaving code deals fairly well with the placement of tasks that are part of workloads that span multiple NUMA nodes, but the code has a number of corner cases left that can result in higher than desired overhead. This patch series reduces the overhead slightly, mostly visible through a lower number of page migrations, while leaving the throughput of the workload essentially unchanged. On smaller NUMA systems, these patches should have little or no effect. On a 4 node test system, I did see a reduction in the number of page migrations running SPECjbb2005; autonuma-benchmark appears to be unaffected. NUMA page migrations on an 8 node system running SPECjbb2005, courtesy of Vinod: vanilla with patch 8 - 1 socket wide: 9138324 8918971 4 - 2 socket wide: 8239914 7315148 2 - 4 socket wide: 5732744 3849624 1 - 8 socket wide: 3348475 2660347