From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752737AbbCZMD5 (ORCPT ); Thu, 26 Mar 2015 08:03:57 -0400 Received: from e33.co.us.ibm.com ([32.97.110.151]:60425 "EHLO e33.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752435AbbCZMDw (ORCPT ); Thu, 26 Mar 2015 08:03:52 -0400 Message-ID: <5513F596.8010406@linux.vnet.ibm.com> Date: Thu, 26 Mar 2015 17:33:34 +0530 From: Preeti U Murthy User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Peter Zijlstra , Vincent Guittot CC: mingo@kernel.org, linux-kernel@vger.kernel.org, Morten.Rasmussen@arm.com, kamalesh@linux.vnet.ibm.com, riel@redhat.com, efault@gmx.de, nicolas.pitre@linaro.org, dietmar.eggemann@arm.com, linaro-kernel@lists.linaro.org Subject: Re: [PATCH v10 10/11] sched: add SD_PREFER_SIBLING for SMT level References: <1425052454-25797-1-git-send-email-vincent.guittot@linaro.org> <1425052454-25797-11-git-send-email-vincent.guittot@linaro.org> <20150326105534.GX21418@twins.programming.kicks-ass.net> In-Reply-To: <20150326105534.GX21418@twins.programming.kicks-ass.net> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15032612-0009-0000-0000-000009B4CE59 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/26/2015 04:25 PM, Peter Zijlstra wrote: > On Fri, Feb 27, 2015 at 04:54:13PM +0100, Vincent Guittot wrote: >> Add the SD_PREFER_SIBLING flag for SMT level in order to ensure that >> the scheduler will put at least 1 task per core. >> >> Signed-off-by: Vincent Guittot >> Reviewed-by: Preeti U. Murthy > > Preeti, what benchmarks did you use on power8 smt to verify performance? > > I'm seeing a slight but statistically significant regression on my > ivb-ep kernel build when I match the build concurrency to my core count. > > /me goes run (and install, its a fairly new box) more benches. I use ebizzy benchmark to test performance regressions. But for this particular patch, I recollect that I did a code walk through to verify the correctness of the patch and not a performance test. Let me run ebizzy against this patch and verify. Regards Preeti U Murthy >