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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 23637C4361B for ; Tue, 15 Dec 2020 11:54:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C0A292228A for ; Tue, 15 Dec 2020 11:54:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728580AbgLOLyJ (ORCPT ); Tue, 15 Dec 2020 06:54:09 -0500 Received: from foss.arm.com ([217.140.110.172]:36430 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726156AbgLOLyJ (ORCPT ); Tue, 15 Dec 2020 06:54:09 -0500 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 8682130E; Tue, 15 Dec 2020 03:53:23 -0800 (PST) Received: from localhost (e108754-lin.cambridge.arm.com [10.1.198.32]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1A8183F66E; Tue, 15 Dec 2020 03:53:22 -0800 (PST) Date: Tue, 15 Dec 2020 11:53:21 +0000 From: Ionela Voinescu To: Viresh Kumar Cc: Catalin Marinas , Will Deacon , Vincent Guittot , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH V3 2/3] arm64: topology: Reorder init_amu_fie() a bit Message-ID: <20201215115321.GA25331@arm.com> References: <5ffc7b9ed03c6301ac2f710f609282959491b526.1608010334.git.viresh.kumar@linaro.org> <87d517c24630494afd9ba5769c2e2b10ee1d3f5d.1608010334.git.viresh.kumar@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87d517c24630494afd9ba5769c2e2b10ee1d3f5d.1608010334.git.viresh.kumar@linaro.org> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday 15 Dec 2020 at 11:04:15 (+0530), Viresh Kumar wrote: > This patch does a couple of optimizations in init_amu_fie(), like early > exits from paths where we don't need to continue any further, avoid the > enable/disable dance, moving the calls to > topology_scale_freq_invariant() just when we need them, instead of at > the top of the routine, and avoiding calling it for the third time. > > Signed-off-by: Viresh Kumar > --- > V3: > - Skipped the enable/disable dance. > - No need to call topology_scale_freq_invariant() multiple times. > > arch/arm64/kernel/topology.c | 27 ++++++++++++++------------- > 1 file changed, 14 insertions(+), 13 deletions(-) > > diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c > index ebadc73449f9..57267d694495 100644 > --- a/arch/arm64/kernel/topology.c > +++ b/arch/arm64/kernel/topology.c > @@ -221,8 +221,8 @@ static DEFINE_STATIC_KEY_FALSE(amu_fie_key); > > static int __init init_amu_fie(void) > { > - bool invariance_status = topology_scale_freq_invariant(); > cpumask_var_t valid_cpus; > + bool invariant; > int ret = 0; > int cpu; > > @@ -249,18 +249,19 @@ static int __init init_amu_fie(void) > if (cpumask_equal(valid_cpus, cpu_present_mask)) > cpumask_copy(amu_fie_cpus, cpu_present_mask); > > - if (!cpumask_empty(amu_fie_cpus)) { > - pr_info("CPUs[%*pbl]: counters will be used for FIE.", > - cpumask_pr_args(amu_fie_cpus)); > - static_branch_enable(&amu_fie_key); > - } > + if (cpumask_empty(amu_fie_cpus)) > + goto free_valid_mask; > > - /* > - * If the system is not fully invariant after AMU init, disable > - * partial use of counters for frequency invariance. > - */ > - if (!topology_scale_freq_invariant()) > - static_branch_disable(&amu_fie_key); > + invariant = topology_scale_freq_invariant(); > + > + /* We aren't fully invariant yet */ > + if (!invariant && !cpumask_equal(amu_fie_cpus, cpu_present_mask)) > + goto free_valid_mask; > + > + static_branch_enable(&amu_fie_key); > + > + pr_info("CPUs[%*pbl]: counters will be used for FIE.", > + cpumask_pr_args(amu_fie_cpus)); > > /* > * Task scheduler behavior depends on frequency invariance support, > @@ -268,7 +269,7 @@ static int __init init_amu_fie(void) > * a result of counter initialisation and use, retrigger the build of > * scheduling domains to ensure the information is propagated properly. > */ > - if (invariance_status != topology_scale_freq_invariant()) > + if (!invariant) > rebuild_sched_domains_energy(); > > free_valid_mask: > -- > 2.25.0.rc1.19.g042ed3e048af > Looks good! Reviewed-by: Ionela Voinescu