From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754489AbcHWHVk (ORCPT ); Tue, 23 Aug 2016 03:21:40 -0400 Received: from mga06.intel.com ([134.134.136.31]:20038 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751847AbcHWHVj (ORCPT ); Tue, 23 Aug 2016 03:21:39 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.28,564,1464678000"; d="scan'208";a="1029879675" Date: Tue, 23 Aug 2016 07:26:37 +0800 From: Yuyang Du To: peterz@infradead.org, mingo@kernel.org, linux-kernel@vger.kernel.org Cc: bsegall@google.com, pjt@google.com, morten.rasmussen@arm.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, matt@codeblueprint.co.uk, umgwanakikbuti@gmail.com Subject: Re: [PATCH v1 00/10] Optimize sched avgs computation and implement flat util hierarchy Message-ID: <20160822232637.GC3273@intel.com> References: <1470788095-2125-1-git-send-email-yuyang.du@intel.com> <20160810002352.GB3273@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160810002352.GB3273@intel.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Peter and others, Could you give this patchset a look? Thanks, Yuyang On Wed, Aug 10, 2016 at 08:23:52AM +0800, Yuyang Du wrote: > On Wed, Aug 10, 2016 at 08:14:45AM +0800, Yuyang Du wrote: > > Hi Peter, > > > > I should have sent out my flat util hierarchy implementation long time ago, > > actually code was there but not rebased. I finally have time to do this, > > so here it is. There are also other proposals to solve migrated tasks' util > > mobility problem, such as the ones from Dietmar and Vincent. > > > > The sched avgs computation optimization was initiated for the flat util thing, > > so I send them out together. > > > > According to Morten and Ben's feedback, I removed 32-bit as a period's upper > > bound limit. So, thanks a lot to them. > > > > To compare the effectiveness of the flat util hierarchy, a simple experiment > was done: rt-app to generate a 50% duty-cycling workload (100us/200us), and > in the meantime a script to set the CPU affinity of the task, alternating > to taskset the task to run on CPU x and CPU y every 0.3 sec, so forcing the > task to ping-pong migrate. By auto-group and ssh itself, the task under test > is at the third level task group. > > So compare the top cfs_rq's util_avg (group_hierarchy.jpg) vs. the rq's util_avg > (flat_hierarchy.jpg) > > Thanks, > Yuyang