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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, 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 454DFC433DB for ; Wed, 10 Mar 2021 13:19:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0C3D064F81 for ; Wed, 10 Mar 2021 13:19:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229658AbhCJNTN (ORCPT ); Wed, 10 Mar 2021 08:19:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44804 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230414AbhCJNSp (ORCPT ); Wed, 10 Mar 2021 08:18:45 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A00E2C061760 for ; Wed, 10 Mar 2021 05:18:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=eis4+R44fvabYv/h8cyHmkDydX2d+usvNs4QgffIqJE=; b=vb69C58Eyeg+N03Qb7GiBVKaYg vvgZFWsgoAihLoxPKehsyjABbBl0jUnlYgYh8Qhe1B7NcSVXKCc5mSlQxOloQPaXhAlfeD6bTacHv Enb5yfEtLYRfQ+wdpmqHHQTRjDhNhVFAqYVHmagGCYbQPILK2Xvp9oniyJyMf3lSs/hFSfBT6dGzE OLpcEC0Ni3BP0GD+FOiGMTDE10NQ2N05wv8TDD1F7f/Y/LpubFmk2Gi0dUKL7DqM5sjmWpYOJ5iws DXwhJKLp6SQm99oCad+v+XBNhiWU8/+K7OYVKDCOlOEGN9DOPV88pIvAoFWfnMFoBL29GzVtSsNX6 mnwkUCRQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94 #2 (Red Hat Linux)) id 1lJyiZ-003Vkg-IK; Wed, 10 Mar 2021 13:17:50 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id AAEA9300455; Wed, 10 Mar 2021 14:17:27 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 7388D20541634; Wed, 10 Mar 2021 14:17:27 +0100 (CET) Date: Wed, 10 Mar 2021 14:17:27 +0100 From: Peter Zijlstra To: Huaixin Chang Cc: bsegall@google.com, dietmar.eggemann@arm.com, juri.lelli@redhat.com, khlebnikov@yandex-team.ru, linux-kernel@vger.kernel.org, mgorman@suse.de, mingo@redhat.com, pauld@redhead.com, pjt@google.com, rostedt@goodmis.org, shanpeic@linux.alibaba.com, vincent.guittot@linaro.org, xiyou.wangcong@gmail.com Subject: Re: [PATCH v3 4/4] sched/fair: Add document for burstable CFS bandwidth control Message-ID: References: <20210121110453.18899-1-changhuaixin@linux.alibaba.com> <20210121110453.18899-5-changhuaixin@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210121110453.18899-5-changhuaixin@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 21, 2021 at 07:04:53PM +0800, Huaixin Chang wrote: > Basic description of usage and effect for CFS Bandwidth Control Burst. > > Signed-off-by: Huaixin Chang > Signed-off-by: Shanpei Chen Guess :-) > +Sometimes users might want a group to burst without accumulation. This is > +tunable via:: > + /proc/sys/kernel/sched_cfs_bw_burst_onset_percent (default=0) > + > +Up to 100% runtime of cpu.cfs_burst_us might be given on setting bandwidth. Sometimes is a very crap reason for code to exist. Also, everything is in _us, why do we have this one thing as a percent?