From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752819AbcGMNtW (ORCPT ); Wed, 13 Jul 2016 09:49:22 -0400 Received: from foss.arm.com ([217.140.101.70]:37008 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751074AbcGMNtO (ORCPT ); Wed, 13 Jul 2016 09:49:14 -0400 Subject: Re: [PATCH v2 06/13] sched: Store maximum per-cpu capacity in root domain To: Vincent Guittot , Morten Rasmussen References: <1466615004-3503-1-git-send-email-morten.rasmussen@arm.com> <1466615004-3503-7-git-send-email-morten.rasmussen@arm.com> Cc: Peter Zijlstra , "mingo@redhat.com" , Yuyang Du , mgalbraith@suse.de, linux-kernel From: Dietmar Eggemann Message-ID: <578646A8.1070607@arm.com> Date: Wed, 13 Jul 2016 14:48:24 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 13/07/16 13:40, Vincent Guittot wrote: > On 22 June 2016 at 19:03, Morten Rasmussen wrote: >> From: Dietmar Eggemann >> >> To be able to compare the capacity of the target cpu with the highest >> available cpu capacity, store the maximum per-cpu capacity in the root >> domain. > > I thought that the capacity of all CPUS were built so the highest > capacity of the CPU of the system is 1024 for big LITTLE system . So > this patch doesn't seem necessary for big.LITTLE system The asymmetric cpu capacity support currently only has an effect on arm big.LITTLE (32bit) using the existing 'struct cpu_efficiency table_efficiency[]' based approach. So e.g. on TC2 we have 1441 for highest capacity. [ 0.041007] SMP: Total of 5 processors activated (240.00 BogoMIPS). [ 0.041024] CPU: All CPU(s) started in SVC mode. [ 0.041103] CPU0 attaching sched-domain: [ 0.041119] domain 0: span 0-1 level MC [ 0.041141] groups: 0 (cpu_capacity = 1441) 1 (cpu_capacity = 1441) [ 0.041179] domain 1: span 0-4 level DIE [ 0.041199] groups: 0-1 (cpu_capacity = 2882) 2-4 (cpu_capacity = 1818) [ 0.041245] CPU1 attaching sched-domain: [ 0.041260] domain 0: span 0-1 level MC [ 0.041279] groups: 1 (cpu_capacity = 1441) 0 (cpu_capacity = 1441) [ 0.041315] domain 1: span 0-4 level DIE [ 0.041334] groups: 0-1 (cpu_capacity = 2882) 2-4 (cpu_capacity = 1818) [ 0.041376] CPU2 attaching sched-domain: [ 0.041391] domain 0: span 2-4 level MC [ 0.041409] groups: 2 (cpu_capacity = 606) 3 (cpu_capacity = 606) 4 (cpu_capacity = 606) [ 0.041460] domain 1: span 0-4 level DIE [ 0.041479] groups: 2-4 (cpu_capacity = 1818) 0-1 (cpu_capacity = 2882) .. [...]