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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9BCECC433F5 for ; Mon, 28 Mar 2022 09:23:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239773AbiC1JZd (ORCPT ); Mon, 28 Mar 2022 05:25:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58848 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239768AbiC1JZb (ORCPT ); Mon, 28 Mar 2022 05:25:31 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 8CAFF1408C for ; Mon, 28 Mar 2022 02:23:51 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3200FD6E; Mon, 28 Mar 2022 02:23:51 -0700 (PDT) Received: from [192.168.178.6] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0D9EF3F66F; Mon, 28 Mar 2022 02:23:47 -0700 (PDT) Message-ID: <6bee2e39-34a8-905f-084f-379b8476ea98@arm.com> Date: Mon, 28 Mar 2022 11:23:46 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH 3/6] sched: Allow sched_{get,set}attr to change latency_nice of the task Content-Language: en-US To: Vincent Guittot , mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, linux-kernel@vger.kernel.org, parth@linux.ibm.com Cc: qais.yousef@arm.com, chris.hyser@oracle.com, pkondeti@codeaurora.org, valentin.schneider@arm.com, patrick.bellasi@matbug.net, David.Laight@aculab.com, pjt@google.com, pavel@ucw.cz, tj@kernel.org, dhaval.giani@oracle.com, qperret@google.com, tim.c.chen@linux.intel.com References: <20220311161406.23497-1-vincent.guittot@linaro.org> <20220311161406.23497-4-vincent.guittot@linaro.org> From: Dietmar Eggemann In-Reply-To: <20220311161406.23497-4-vincent.guittot@linaro.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/03/2022 17:14, Vincent Guittot wrote: [...] > @@ -98,6 +99,22 @@ struct sched_param { > * scheduled on a CPU with no more capacity than the specified value. > * > * A task utilization boundary can be reset by setting the attribute to -1. > + * > + * Latency Tolerance Attributes > + * =========================== > + * > + * A subset of sched_attr attributes allows to specify the relative latency > + * requirements of a task with respect to the other tasks running/queued in the > + * system. > + * > + * @ sched_latency_nice task's latency_nice value > + * > + * The latency_nice of a task can have any value in a range of > + * [LATENCY_NICE_MIN..LATENCY_NICE_MAX]. s/LATENCY_NICE_MIN/MIN_LATENCY_NICE s/LATENCY_NICE_MAX/MAX_LATENCY_NICE > + * A task with latency_nice with the value of LATENCY_NICE_MIN can be > + * taken for a task with lower latency requirements as opposed to the task with > + * higher latency_nice. low latency nice (priority): -20 -> high weight: 1024 ... Doesn't a task with MIN_LATENCY_NICE -20 have the highest latency requirements? [...]