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=-8.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 BC4CCC43461 for ; Thu, 3 Sep 2020 14:49:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 932BC2072A for ; Thu, 3 Sep 2020 14:49:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728596AbgICOte (ORCPT ); Thu, 3 Sep 2020 10:49:34 -0400 Received: from foss.arm.com ([217.140.110.172]:34558 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729161AbgICOTS (ORCPT ); Thu, 3 Sep 2020 10:19:18 -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 B7BC11045; Thu, 3 Sep 2020 07:19:17 -0700 (PDT) Received: from bogus (unknown [10.57.4.218]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DDCF03F71F; Thu, 3 Sep 2020 07:19:15 -0700 (PDT) Date: Thu, 3 Sep 2020 15:19:09 +0100 From: Sudeep Holla To: Ionela Voinescu Cc: rjw@rjwysocki.net, viresh.kumar@linaro.org, dietmar.eggemann@arm.com, catalin.marinas@arm.com, will@kernel.org, valentin.schneider@arm.com, linux-pm@vger.kernel.org, Sudeep Holla , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 3/5] cpufreq: report whether cpufreq supports Frequency Invariance (FI) Message-ID: <20200903141909.GA6492@bogus> References: <20200901205549.30096-1-ionela.voinescu@arm.com> <20200901205549.30096-4-ionela.voinescu@arm.com> <20200902132838.GF25462@bogus> <20200903134508.GB29370@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200903134508.GB29370@arm.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Thu, Sep 03, 2020 at 02:45:08PM +0100, Ionela Voinescu wrote: > Hi Sudeep, > > Thank you for your review here and for the other patches. > > On Wednesday 02 Sep 2020 at 14:28:38 (+0100), Sudeep Holla wrote: > [..] > > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > > > index 4d5fe777184a..570bf2ebe9d4 100644 > > > --- a/drivers/cpufreq/cpufreq.c > > > +++ b/drivers/cpufreq/cpufreq.c > > > @@ -61,6 +61,12 @@ static struct cpufreq_driver *cpufreq_driver; > > > static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); > > > static DEFINE_RWLOCK(cpufreq_driver_lock); > > > > > > +static DEFINE_STATIC_KEY_FALSE(cpufreq_freq_invariance); > > > +bool cpufreq_supports_freq_invariance(void) > > > +{ > > > + return static_branch_likely(&cpufreq_freq_invariance); > > > +} > > > + > > > /* Flag to suspend/resume CPUFreq governors */ > > > static bool cpufreq_suspended; > > > > > > @@ -2720,6 +2726,15 @@ int cpufreq_register_driver(struct cpufreq_driver *driver_data) > > > cpufreq_driver = driver_data; > > > write_unlock_irqrestore(&cpufreq_driver_lock, flags); > > > > > > + /* > > > + * Mark support for the scheduler's frequency invariance engine for > > > + * drivers that implement target(), target_index() or fast_switch(). > > > + */ > > > + if (!cpufreq_driver->setpolicy) { > > > + static_branch_enable_cpuslocked(&cpufreq_freq_invariance); > > > + pr_debug("supports frequency invariance"); > > > + } > > > + > > > if (driver_data->setpolicy) > > > > [super nit] while I understand cpufreq_driver = driver_data, it looks odd > > if 2 consecutive statements refer it with different variables. Or am I > > confusing myself hugely. > > > > No, you are right. If you look at the rest of the register function, > after cpufreq_driver = driver_data, both driver_data and cpufreq_driver > are used. For me using cpufreq_driver seemed more natural as after being > assigned driver_data, it will continue to be used after registration. > Ah OK, I haven't seen the whole file/function, just looked at the patch. > If it's alright with you I won't make this change for now. It's possible > that a better solution is to change the other occurrences of either > cpufreq_driver or driver_data in a separate patch, to make things > consistent across the function. > I am fine to keep it as is, hence I mentioned it as super nit. If there are other occurrences, then better to take it up separately. -- Regards, Sudeep