From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752347AbeDOL5D (ORCPT ); Sun, 15 Apr 2018 07:57:03 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:52012 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751190AbeDOL5C (ORCPT ); Sun, 15 Apr 2018 07:57:02 -0400 Subject: Re: [PATCH 0/4 v4] sched/rt: track rt rq utilization To: Vincent Guittot , peterz@infradead.org, mingo@kernel.org, linux-kernel@vger.kernel.org, rjw@rjwysocki.net Cc: juri.lelli@redhat.com, Morten.Rasmussen@arm.com, viresh.kumar@linaro.org, valentin.schneider@arm.com References: <1521199541-15308-1-git-send-email-vincent.guittot@linaro.org> From: Dietmar Eggemann Message-ID: <08e478a1-e1ff-4547-b95b-2975bc5c5b5d@arm.com> Date: Sun, 15 Apr 2018 13:56:53 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <1521199541-15308-1-git-send-email-vincent.guittot@linaro.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/16/2018 12:25 PM, Vincent Guittot wrote: [...] > For a 15 seconds long test on a hikey 6220 (octo core cortex A53 platfrom), > the cpufreq statistics outputs (stats are reset just before the test) : > $ cat /sys/devices/system/cpu/cpufreq/policy0/stats/total_trans > without patchset : 1230 > with patchset : 14 > > If we replace the cfs thread of rt-app by a sysbench cpu test, we can see > performance improvements: > > - Without patchset : > Test execution summary: > total time: 15.0009s > total number of events: 4903 > total time taken by event execution: 14.9972 > per-request statistics: > min: 1.23ms > avg: 3.06ms > max: 13.16ms > approx. 95 percentile: 12.73ms > > Threads fairness: > events (avg/stddev): 4903.0000/0.00 > execution time (avg/stddev): 14.9972/0.00 > > - With patchset: > Test execution summary: > total time: 15.0014s > total number of events: 7694 > total time taken by event execution: 14.9979 > per-request statistics: > min: 1.23ms > avg: 1.95ms > max: 10.49ms > approx. 95 percentile: 10.39ms > > Threads fairness: > events (avg/stddev): 7694.0000/0.00 > execution time (avg/stddev): 14.9979/0.00 > > The performance improvement is 56% for this use case. How do you get this number? Normally we use the 'total time' value. [...]