From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751247AbbCIDh7 (ORCPT ); Sun, 8 Mar 2015 23:37:59 -0400 Received: from mail-qg0-f46.google.com ([209.85.192.46]:39707 "EHLO mail-qg0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750830AbbCIDh6 (ORCPT ); Sun, 8 Mar 2015 23:37:58 -0400 Date: Sun, 8 Mar 2015 23:37:54 -0400 From: Tejun Heo To: riel@redhat.com Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 0/4] cpusets,isolcpus: exclude isolcpus from load balancing in cpusets Message-ID: <20150309033754.GF13283@htj.duckdns.org> References: <1425423623-31316-1-git-send-email-riel@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1425423623-31316-1-git-send-email-riel@redhat.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 03, 2015 at 06:00:19PM -0500, riel@redhat.com wrote: > Ensure that cpus specified with the isolcpus= boot commandline > option stay outside of the load balancing in the kernel scheduler. > > Operations like load balancing can introduce unwanted latencies, > which is exactly what the isolcpus= commandline is there to prevent. > > Previously, simply creating a new cpuset, without even touching the > cpuset.cpus field inside the new cpuset, would undo the effects of > isolcpus=, by creating a scheduler domain spanning the whole system, > and setting up load balancing inside that domain. The cpuset root > cpuset.cpus file is read-only, so there was not even a way to undo > that effect. > > This does not impact the majority of cpusets users, since isolcpus= > is a fairly specialized feature used for realtime purposes. > > This version fixes the UP compilation issue, in the same way done > for the other cpumasks. Can you please repost with Li Zefan and cgroups@vger.kernel.org cc'd? Thanks. -- tejun