From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756058Ab2FTJiH (ORCPT ); Wed, 20 Jun 2012 05:38:07 -0400 Received: from e28smtp03.in.ibm.com ([122.248.162.3]:37571 "EHLO e28smtp03.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752150Ab2FTJiB (ORCPT ); Wed, 20 Jun 2012 05:38:01 -0400 Message-ID: <4FE199B6.2050803@linux.vnet.ibm.com> Date: Wed, 20 Jun 2012 15:06:54 +0530 From: "Srivatsa S. Bhat" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120424 Thunderbird/12.0 MIME-Version: 1.0 To: Peter Zijlstra CC: "Srivatsa S. Bhat" , mingo@kernel.org, pjt@google.com, paul@paulmenage.org, akpm@linux-foundation.org, rjw@sisk.pl, nacc@us.ibm.com, rientjes@google.com, paulmck@linux.vnet.ibm.com, tglx@linutronix.de, seto.hidetoshi@jp.fujitsu.com, tj@kernel.org, mschmidt@redhat.com, berrange@redhat.com, nikunj@linux.vnet.ibm.com, vatsa@linux.vnet.ibm.com, liuj97@gmail.com, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Subject: Re: [PATCH v6 0/4] CPU hotplug, cpusets, suspend/resume: Fixes, cleanups and optimizations References: <20120524141510.3692.64549.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20120524141510.3692.64549.stgit@srivatsabhat.in.ibm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit x-cbid: 12062009-3864-0000-0000-0000036996B1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/24/2012 07:46 PM, Srivatsa S. Bhat wrote: > Currently the kernel doesn't handle cpusets properly during suspend/resume. > After a resume, all non-root cpusets end up having only 1 cpu (the boot cpu), > causing massive performance degradation of workloads. One major user of cpusets > is libvirt, which means that after a suspend/hibernation cycle, all VMs > suddenly end up running terribly slow! > > Also, the kernel moves the tasks from one cpuset to another during CPU hotplug > in the suspend/resume path, leading to a task-management nightmare after > resume. > > Patch 1 fixes this by keeping cpusets unmodified in the suspend/resume path. > But to ensure we don't trip over, it keeps the sched domains updated during > every CPU hotplug in the s/r path. > This is a long standing issue and we need to fix up stable kernels too. > > The rest of the patches in the series are mostly cleanups/optimizations. > Hi Peter, Would you be taking these patches through -tip for 3.6? Regards, Srivatsa S. Bhat