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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_2 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 85DBEC433DB for ; Wed, 3 Feb 2021 09:57:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3D30364E2A for ; Wed, 3 Feb 2021 09:57:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233509AbhBCJ50 (ORCPT ); Wed, 3 Feb 2021 04:57:26 -0500 Received: from mx2.suse.de ([195.135.220.15]:40616 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233614AbhBCJ47 (ORCPT ); Wed, 3 Feb 2021 04:56:59 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 65A0BAF4C; Wed, 3 Feb 2021 09:56:17 +0000 (UTC) Message-ID: <1612346175.3640.32.camel@suse.cz> Subject: Re: [PATCH v2 1/1] x86,sched: On AMD EPYC set freq_max = max_boost in schedutil invariant formula From: Giovanni Gherdovich To: "Rafael J. Wysocki" Cc: Peter Zijlstra , Borislav Petkov , Ingo Molnar , "Rafael J . Wysocki" , Viresh Kumar , Jon Grimm , Nathan Fontenot , Yazen Ghannam , Thomas Lendacky , Suthikulpanit Suravee , Mel Gorman , Pu Wen , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Michael Larabel , the arch/x86 maintainers , Linux PM , Linux Kernel Mailing List , ACPI Devel Maling List Date: Wed, 03 Feb 2021 10:56:15 +0100 In-Reply-To: References: <20210122204038.3238-1-ggherdovich@suse.cz> <20210122204038.3238-2-ggherdovich@suse.cz> <1611653310.11983.66.camel@suse.cz> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.26.6 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2021-02-02 at 20:11 +0100, Rafael J. Wysocki wrote: > On Tue, Feb 2, 2021 at 7:45 PM Rafael J. Wysocki wrote: > > > > On Tue, Jan 26, 2021 at 5:19 PM Giovanni Gherdovich wrote: > > > > > > > > > cpufreq core asks the driver what's the f_max. What's the answer? > > > > > > intel_pstate says: 1C > > > > Yes, unless turbo is disabled, in which case it is P0. > > BTW, and that actually is quite important, the max_freq reported by > intel_pstate doesn't matter for schedutil after the new ->adjust_perf > callback has been added, because that doesn't even use the frequency. > > So, as a long-term remedy, it may just be better to implement > ->adjust_perf in acpi_cpufreq(). Thanks for pointing this out. I agree that in the long term adding ->adjust_perf to acpi_cpufreq is the best solution. Yet for this submission, considering it's late in the 5.11 cycle, the patch I propose is a reasonable candidate: the footprint is small and it's gone through a fair amount of testing. Thanks, Giovanni