Received: by 2002:a25:ad19:0:0:0:0:0 with SMTP id y25csp1195712ybi; Tue, 16 Jul 2019 11:02:53 -0700 (PDT) X-Google-Smtp-Source: APXvYqwZ/YRs44y/BhQuhpE+W6gSrU4ux+h7OsFZrf1sTxJvLy+A5eANviAsz2aD8XMgtfD8IP/b X-Received: by 2002:a17:90a:220a:: with SMTP id c10mr39138738pje.33.1563300173202; Tue, 16 Jul 2019 11:02:53 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1563300173; cv=none; d=google.com; s=arc-20160816; b=XmWCmk+RAlF74qJeSWKRCOgMIpUW9xN2Hy/ifFLidX9ZuGJfSYEcUZYD5b3mf5W4Yy xcQ4O196xK2/tPl8K6DuR7Cl74lqogrZatF3JNjHJJzfesBpDrjw2gocjhoArAXKjdaK Q3RhIeRYnNMJSqzu2yNha5A9Jf+Tce4Qk9SAPuWr0VBgawSgL4kRYZvEZXvARgAuk75+ hAbm4PWMcTAXhNElmtrNU/MTcVl/ZWKw+KkMBK2nYsLOna/tCJyRdbWiq3Bs1xD4D89Q SNvmkIKhf0GTeM6Iq3Oq/TqV11IQm8IWawMyg+7cGT1Yhjh79skEnEjR0K6fhZ8NfyTM BNtA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-transfer-encoding:content-disposition:mime-version :references:message-id:subject:cc:to:from:date; bh=wKfCvO3FQkfOOtrMeRWzccwd90OeCGei069SSrLAvEI=; b=JfIXlq0CeQVJJyVf/lBgS3vsNpzw9ANYK4Aw0kav9jC7sc2l/5ee9wmh7ksNdat2ua M0et61qYjS/poq12Irct89TzhzDpeIdyTmm5yhJao/dpQLCi7zLr28jWN64Kz3EoEyME joR4lfhynGBUAOAGldXmhNDN23Tb7wApzWNdFEHmEBA+GIRfyxnW/TJqTdrNksBVSuZd /ljcdcCHuhvrckz+4G/iLSzwUEumgRt6ANQ0ipzL5B8kV+sCvpK8exwuSUx3n1tluJbn jAWFBkkc3x7QloNPgtPXsJjr/mSy+hqJ2dsFEROIkI3uGtAkwlXkB3BEZxaLIYyi7kH5 +PmA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id 60si14607218plf.398.2019.07.16.11.02.34; Tue, 16 Jul 2019 11:02:53 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388172AbfGPSAO (ORCPT + 99 others); Tue, 16 Jul 2019 14:00:14 -0400 Received: from foss.arm.com ([217.140.110.172]:38338 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728137AbfGPSAN (ORCPT ); Tue, 16 Jul 2019 14:00:13 -0400 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 E9DAE344; Tue, 16 Jul 2019 11:00:12 -0700 (PDT) Received: from e110439-lin (e110439-lin.cambridge.arm.com [10.1.194.43]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 92D923F71A; Tue, 16 Jul 2019 11:00:10 -0700 (PDT) Date: Tue, 16 Jul 2019 19:00:08 +0100 From: Patrick Bellasi To: Michal =?utf-8?Q?Koutn=C3=BD?= Cc: Alessio Balsini , Dietmar Eggemann , Morten Rasmussen , Quentin Perret , Joel Fernandes , Paul Turner , Steve Muckle , Suren Baghdasaryan , Todd Kjos , Peter Zijlstra , "Rafael J . Wysocki" , Tejun Heo , Vincent Guittot , Viresh Kumar , Juri Lelli , Ingo Molnar , linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Subject: Re: [PATCH v11 3/5] sched/core: uclamp: Propagate system defaults to root group Message-ID: <20190716180008.duvovlu2u7gxyhmc@e110439-lin> References: <20190708084357.12944-1-patrick.bellasi@arm.com> <20190708084357.12944-4-patrick.bellasi@arm.com> <20190715164226.GA30262@blackbody.suse.cz> <20190716143417.us3xhksrsaxsl2ok@e110439-lin> <20190716153610.GE32540@blackbody.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20190716153610.GE32540@blackbody.suse.cz> User-Agent: NeoMutt/20180716 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 16-Jul 17:36, Michal Koutn? wrote: > On Tue, Jul 16, 2019 at 03:34:17PM +0100, Patrick Bellasi wrote: > > > cpu_util_update_eff internally calls css_for_each_descendant_pre() so > > > this should be protected with rcu_read_lock(). > > > > Right, good catch! Will add in v12. > When I responded to your other patch, it occurred to me that since > cpu_util_update_eff goes writing down to child csses, it should take > also uclamp_mutex here to avoid race with direct cgroup attribute > writers. Yep, I should drop the "dedicated" mutex we have now in sysctl_sched_uclamp_handler() and use the uclamp_mutex we already have. Thanks, Patrick -- #include Patrick Bellasi