Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932559AbaFCOCl (ORCPT ); Tue, 3 Jun 2014 10:02:41 -0400 Received: from mail-ob0-f177.google.com ([209.85.214.177]:33916 "EHLO mail-ob0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754425AbaFCOCj (ORCPT ); Tue, 3 Jun 2014 10:02:39 -0400 MIME-Version: 1.0 In-Reply-To: <20140603132217.GD29593@e103034-lin> References: <1400860385-14555-1-git-send-email-vincent.guittot@linaro.org> <1400860385-14555-5-git-send-email-vincent.guittot@linaro.org> <20140603132217.GD29593@e103034-lin> From: Vincent Guittot Date: Tue, 3 Jun 2014 16:02:18 +0200 Message-ID: Subject: Re: [PATCH v2 04/11] sched: Allow all archs to set the power_orig To: Morten Rasmussen Cc: "peterz@infradead.org" , "mingo@kernel.org" , "linux-kernel@vger.kernel.org" , "linux@arm.linux.org.uk" , "linux-arm-kernel@lists.infradead.org" , "preeti@linux.vnet.ibm.com" , "efault@gmx.de" , "nicolas.pitre@linaro.org" , "linaro-kernel@lists.linaro.org" , "daniel.lezcano@linaro.org" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3 June 2014 15:22, Morten Rasmussen wrote: > On Fri, May 23, 2014 at 04:52:58PM +0100, Vincent Guittot wrote: >> power_orig is only changed for system with a SMT sched_domain level in order to >> reflect the lower capacity of CPUs. Heterogenous system also have to reflect an >> original capacity that is different from the default value. >> >> Create a more generic function arch_scale_cpu_power that can be also used by >> non SMT platform to set power_orig. > > I did a quick test of the patch set with adjusting cpu_power on > big.LITTLE (ARM TC2) to reflect the different compute capacities of the > A15s and A7s. I ran the sysbench cpu benchmark with 5 threads with and > without the patches applied, but with non-default cpu_powers. > > I didn't see any difference in the load-balance. Three tasks ended up on > the two A15s and two tasks ended up on two of the three A7s leaving one > unused in both cases. > > Using default cpu_power I get one task on each of the five cpus (best > throughput). Unless I messed something up, it seems that setting > cpu_power doesn't give me the best throughput with these patches > applied. That's normal this patchset is necessary but not enough to solve the issue you mention. We also need to fix the way the imbalance is calculated for such situation. I have planned to push that in another patchset in order to not mix too much thing together Vincent > > Have you done any tests on big.LITTLE? > > Morten -- 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/