From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755919Ab2DXRIJ (ORCPT ); Tue, 24 Apr 2012 13:08:09 -0400 Received: from e28smtp02.in.ibm.com ([122.248.162.2]:58883 "EHLO e28smtp02.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755481Ab2DXRIG (ORCPT ); Tue, 24 Apr 2012 13:08:06 -0400 Date: Tue, 24 Apr 2012 22:37:43 +0530 From: Srivatsa Vaddagiri To: Peter Zijlstra Cc: Ingo Molnar , Mike Galbraith , Suresh Siddha , Paul Turner , linux-kernel@vger.kernel.org Subject: Re: [PATCH v1] sched: steer waking task to empty cfs_rq for better latencies Message-ID: <20120424170743.GA18799@linux.vnet.ibm.com> Reply-To: Srivatsa Vaddagiri References: <20120424165619.GA28701@linux.vnet.ibm.com> <1335286696.28150.206.camel@twins> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <1335286696.28150.206.camel@twins> User-Agent: Mutt/1.5.21 (2010-09-15) x-cbid: 12042417-5816-0000-0000-00000246D00A Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Peter Zijlstra [2012-04-24 18:58:16]: > On Tue, 2012-04-24 at 22:26 +0530, Srivatsa Vaddagiri wrote: > > Steer a waking task towards a cpu where its cgroup has zero tasks (in > > order to provide it better sleeper credits and hence reduce its wakeup > > latency). > > That's just vile.. pjt could you post your global vruntime stuff so > vatsa can have a go at that? The workload I am up against does experience tons of wakeup (after very short (microsecond range) bursts of sleeps) and so am skeptical how the global vruntime would keep up with this kind of workload. I'd be happy to test patches and give feedback! - vatsa