From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4173EC10F0E for ; Mon, 15 Apr 2019 10:27:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1A5DC20883 for ; Mon, 15 Apr 2019 10:27:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726095AbfDOK1h (ORCPT ); Mon, 15 Apr 2019 06:27:37 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:60164 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726034AbfDOK1g (ORCPT ); Mon, 15 Apr 2019 06:27:36 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 58A7E80D; Mon, 15 Apr 2019 03:27:36 -0700 (PDT) Received: from [0.0.0.0] (e107985-lin.cambridge.arm.com [10.1.194.38]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B7F783F557; Mon, 15 Apr 2019 03:27:35 -0700 (PDT) Subject: Re: [RFC 5/6] Improvise cgroup interface for classifying jitter from WOF tasks To: Parth Shah , linux-pm@vger.kernel.org References: <20190322060621.27021-1-parth015@linux.vnet.ibm.com> <20190322060621.27021-6-parth015@linux.vnet.ibm.com> <8de36526-806a-810f-9f5e-393dddb523be@arm.com> <9aeb5767-82b3-77c1-5334-193236e8a786@linux.vnet.ibm.com> From: Dietmar Eggemann Message-ID: <35addb7c-1ed9-3115-4e44-bfb3b55c7575@arm.com> Date: Mon, 15 Apr 2019 12:27:33 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <9aeb5767-82b3-77c1-5334-193236e8a786@linux.vnet.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On 4/12/19 5:48 PM, Parth Shah wrote: > > > On 4/12/19 6:38 PM, Dietmar Eggemann wrote: >> On 3/22/19 7:06 AM, Parth Shah wrote: [...] > Maybe the comment is not self-explainable. Please follow a below one, > > Here we have two cpumask to iterate through > 1. wof_tasks_cpu_mask which contains CPU occupied by user classified task and is hence easier to track > 2. highutil_task_cpu_mask which contains CPU which are non-idle (not core_underutilized) > > So, the selection of "cpus" can be either from the above two masks. > Selecting "wof_tasks_cpu_mask" leads to quicker and better selection of non idle CPU, > whereas "highutil_task_cpu_mask" will contain more CPUs (inclusive of wof_tasks_cpu_mask) and hence finding perfect CPU may require more iterations. > > Hence, selecting "highutil_task_cpu_mask" is relatively exhaustive (which I termed "longer code path") in general cases. > > Hope this helps. Ah, OK, that helped to understand it. [...]