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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 1A2C5C4727D for ; Thu, 24 Sep 2020 16:10:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C1BBE239CF for ; Thu, 24 Sep 2020 16:10:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728606AbgIXQKE (ORCPT ); Thu, 24 Sep 2020 12:10:04 -0400 Received: from foss.arm.com ([217.140.110.172]:50056 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728448AbgIXQKE (ORCPT ); Thu, 24 Sep 2020 12:10:04 -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 F01961396; Thu, 24 Sep 2020 09:10:03 -0700 (PDT) Received: from localhost (unknown [10.1.199.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 91EFB3F718; Thu, 24 Sep 2020 09:10:03 -0700 (PDT) Date: Thu, 24 Sep 2020 17:10:02 +0100 From: Ionela Voinescu To: Quentin Perret Cc: mingo@redhat.com, peterz@infradead.org, vincent.guittot@linaro.org, catalin.marinas@arm.com, will@kernel.org, rjw@rjwysocki.net, viresh.kumar@linaro.org, dietmar.eggemann@arm.com, valentin.schneider@arm.com, linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/3] arm64: rebuild sched domains on invariance status changes Message-ID: <20200924161002.GC17927@arm.com> References: <20200924123937.20938-1-ionela.voinescu@arm.com> <20200924123937.20938-4-ionela.voinescu@arm.com> <20200924133925.GC3920949@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200924133925.GC3920949@google.com> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thursday 24 Sep 2020 at 14:39:25 (+0100), Quentin Perret wrote: > On Thursday 24 Sep 2020 at 13:39:37 (+0100), Ionela Voinescu wrote: > > For arm64 this affects the task scheduler behavior which builds its > > scheduling domain hierarchy well before the late counter-based FI init. > > During that process it will disable EAS due to its dependency on FI. > > Does it mean we get a warn on every boot, even though this is a > perfectly normal scenario? > Yes, we will get a few "Disabling EAS: frequency-invariant load tracking not supported" warnings until the final rebuild of the sched domains finds FI supported and enables EAS (silently this time, which possibly makes things worse). We have the same behavior for removing and adding the schedutil governor. I'm not sure what is a good way of fixing this.. I could add more info to the warning to suggest it might be temporary ("Disabling EAS: frequency-invariant load tracking currently not supported"). For further debugging there are the additional prints guarded by sched_debug(). I'll look over the code some more to see if other ideas pop out. Any suggestions are appreciated. Many thanks for the review, Ionela. > Thanks, > Quentin