Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755703Ab3DZPLr (ORCPT ); Fri, 26 Apr 2013 11:11:47 -0400 Received: from mout.gmx.net ([212.227.17.22]:58589 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751396Ab3DZPLo (ORCPT ); Fri, 26 Apr 2013 11:11:44 -0400 X-Authenticated: #14349625 X-Provags-ID: V01U2FsdGVkX1+mmjk3ZT2mFkBLvD5V4oqaS6uUNwtd/1GgcggoSD I3yerEo5WIdnj2 Message-ID: <1366989087.30242.11.camel@marge.simpson.net> Subject: Re: [patch v7 0/21] sched: power aware scheduling From: Mike Galbraith To: Len Brown Cc: Borislav Petkov , Alex Shi , mingo@redhat.com, peterz@infradead.org, tglx@linutronix.de, akpm@linux-foundation.org, arjan@linux.intel.com, pjt@google.com, namhyung@kernel.org, morten.rasmussen@arm.com, vincent.guittot@linaro.org, gregkh@linuxfoundation.org, preeti@linux.vnet.ibm.com, viresh.kumar@linaro.org, linux-kernel@vger.kernel.org, len.brown@intel.com, rafael.j.wysocki@intel.com, jkosina@suse.cz, clark.williams@gmail.com, tony.luck@intel.com, keescook@chromium.org, mgorman@suse.de, riel@redhat.com, Linux PM list Date: Fri, 26 Apr 2013 17:11:27 +0200 In-Reply-To: <516F19EE.5060309@kernel.org> References: <1365040862-8390-1-git-send-email-alex.shi@intel.com> <516724F5.20504@kernel.org> <5167C9FA.8050406@intel.com> <20130412162348.GE2368@pd.tnic> <1365785311.5814.36.camel@marge.simpson.net> <516F19EE.5060309@kernel.org> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1825 Lines: 42 On Wed, 2013-04-17 at 17:53 -0400, Len Brown wrote: > On 04/12/2013 12:48 PM, Mike Galbraith wrote: > > On Fri, 2013-04-12 at 18:23 +0200, Borislav Petkov wrote: > >> On Fri, Apr 12, 2013 at 04:46:50PM +0800, Alex Shi wrote: > >>> Thanks a lot for comments, Len! > >> > >> AFAICT, you kinda forgot to answer his most important question: > >> > >>> These numbers suggest that this patch series simultaneously > >>> has a negative impact on performance and energy required > >>> to retire the workload. Why do it? > > > > Hm. When I tested AIM7 compute on a NUMA box, there was a marked > > throughput increase at the low to moderate load end of the test spectrum > > IIRC. Fully repeatable. There were also other benefits unrelated to > > power, ie mitigation of the evil face of select_idle_sibling(). I > > rather liked what I saw during ~big box test-drive. > > > > (just saying there are other aspects besides joules in there) > > Mike, > > Can you re-run your AIM7 measurement with turbo-mode and HT-mode disabled, > and then independently re-enable them? > > If you still see the performance benefit, then that proves > that the scheduler hacks are not about tricking into > turbo mode, but something else. I did that today, neither turbo nor HT affected the performance gain. I used the same box and patch set as tested before (v4), but plugged into linus HEAD. "powersaving" AIM7 numbers are ~identical to those I posted before, "performance" is lower at the low end of AIM7 test spectrum, but as before, delta goes away once the load becomes hefty. -Mike -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/