From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760469AbZFQTV5 (ORCPT ); Wed, 17 Jun 2009 15:21:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753303AbZFQTVu (ORCPT ); Wed, 17 Jun 2009 15:21:50 -0400 Received: from e23smtp02.au.ibm.com ([202.81.31.144]:37805 "EHLO e23smtp02.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752945AbZFQTVt (ORCPT ); Wed, 17 Jun 2009 15:21:49 -0400 Date: Thu, 18 Jun 2009 00:51:16 +0530 From: Vaidyanathan Srinivasan To: venkatesh.pallipadi@intel.com Cc: Peter Zijlstra , Gautham R Shenoy , Ingo Molnar , Thomas Gleixner , Arjan van de Ven , linux-kernel@vger.kernel.org, Suresh Siddha Subject: Re: [patch 2/2] RFC sched: Scale the nohz_tracker logic by making it per NUMA node Message-ID: <20090617192116.GI7961@dirshya.in.ibm.com> Reply-To: svaidy@linux.vnet.ibm.com References: <20090617182649.604970000@intel.com> <20090617182741.107659000@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20090617182741.107659000@intel.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * venkatesh.pallipadi@intel.com [2009-06-17 11:26:51]: > Having one idle CPU doing the rebalancing for all the idle CPUs in > nohz mode does not scale well with increasing number of cores and > sockets. Make the nohz_tracker per NUMA node. This results in multiple > idle load balancing happening at NUMA node level and idle load balancer > only does the rebalance domain among all the other nohz CPUs in that > NUMA node. This is a good optimisations but maybe an overkill for single chip NUMA node machines like a two socket Nehalems or Optrons. Some method to create load balancer group based on the scale of the machine will be good. --Vaidy