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 EF100C433E6 for ; Wed, 17 Feb 2021 00:25:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ADED864E2B for ; Wed, 17 Feb 2021 00:25:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229806AbhBQAZR (ORCPT ); Tue, 16 Feb 2021 19:25:17 -0500 Received: from foss.arm.com ([217.140.110.172]:46534 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231344AbhBQAZM (ORCPT ); Tue, 16 Feb 2021 19:25:12 -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 5E3BD31B; Tue, 16 Feb 2021 16:24:24 -0800 (PST) Received: from localhost (e108754-lin.cambridge.arm.com [10.1.195.40]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E39B53F73D; Tue, 16 Feb 2021 16:24:23 -0800 (PST) Date: Wed, 17 Feb 2021 00:24:22 +0000 From: Ionela Voinescu To: Viresh Kumar Cc: Rafael Wysocki , Catalin Marinas , Will Deacon , Vincent Guittot , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org, Sudeep Holla , Greg Kroah-Hartman Subject: Re: [PATCH V3 1/2] topology: Allow multiple entities to provide sched_freq_tick() callback Message-ID: <20210217002422.GA17422@arm.com> References: <20210203114521.GA6380@arm.com> <20210205091424.3od3tme3f7mh7ebp@vireshk-i7> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210205091424.3od3tme3f7mh7ebp@vireshk-i7> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Hey, On Friday 05 Feb 2021 at 14:44:24 (+0530), Viresh Kumar wrote: > On 03-02-21, 11:45, Ionela Voinescu wrote: > > Therefore, I think system level invariance management (checks and > > call to rebuild_sched_domains_energy()) also needs to move from arm64 > > code to arch_topology code. > > Here is the 3rd patch of this series then :) > I think it could be merged in patch 1/2 as it's part of enabling the use of multiple sources of information for FIE. Up to you! > From: Viresh Kumar > Date: Fri, 5 Feb 2021 13:31:53 +0530 > Subject: [PATCH] drivers: arch_topology: rebuild sched domains on invariance > change > > We already do this for the arm64, move it to arch_topology.c as we > manage all sched_freq_tick sources here now. > > Reported-by: Ionela Voinescu > Signed-off-by: Viresh Kumar > --- > arch/arm64/kernel/topology.c | 16 ---------------- > drivers/base/arch_topology.c | 22 ++++++++++++++++++++++ > 2 files changed, 22 insertions(+), 16 deletions(-) > > diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c > index 1e47dfd465f8..47fca7376c93 100644 > --- a/arch/arm64/kernel/topology.c > +++ b/arch/arm64/kernel/topology.c > @@ -240,7 +240,6 @@ static struct scale_freq_data amu_sfd = { > > static void amu_fie_setup(const struct cpumask *cpus) > { > - bool invariant; > int cpu; > > /* We are already set since the last insmod of cpufreq driver */ > @@ -257,25 +256,10 @@ static void amu_fie_setup(const struct cpumask *cpus) > > cpumask_or(amu_fie_cpus, amu_fie_cpus, cpus); > > - invariant = topology_scale_freq_invariant(); > - > - /* We aren't fully invariant yet */ > - if (!invariant && !cpumask_equal(amu_fie_cpus, cpu_present_mask)) > - return; > - You still need these checks, otherwise you could end up with only part of the CPUs setting a scale factor, when only part of the CPUs support AMUs and there is no cpufreq support for FIE. > topology_set_scale_freq_source(&amu_sfd, amu_fie_cpus); > > pr_debug("CPUs[%*pbl]: counters will be used for FIE.", > cpumask_pr_args(cpus)); > - > - /* > - * Task scheduler behavior depends on frequency invariance support, > - * either cpufreq or counter driven. If the support status changes as > - * a result of counter initialisation and use, retrigger the build of > - * scheduling domains to ensure the information is propagated properly. > - */ > - if (!invariant) > - rebuild_sched_domains_energy(); > } > > static int init_amu_fie_callback(struct notifier_block *nb, unsigned long val, > diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c > index 20b511949cd8..3631877f4440 100644 > --- a/drivers/base/arch_topology.c > +++ b/drivers/base/arch_topology.c > @@ -23,6 +23,7 @@ > > static DEFINE_PER_CPU(struct scale_freq_data *, sft_data); > static struct cpumask scale_freq_counters_mask; > +static bool scale_freq_invariant; > > static bool supports_scale_freq_counters(const struct cpumask *cpus) > { > @@ -35,6 +36,23 @@ bool topology_scale_freq_invariant(void) > supports_scale_freq_counters(cpu_online_mask); > } > > +static void update_scale_freq_invariant(bool status) > +{ > + if (scale_freq_invariant == status) > + return; > + > + /* > + * Task scheduler behavior depends on frequency invariance support, > + * either cpufreq or counter driven. If the support status changes as > + * a result of counter initialisation and use, retrigger the build of > + * scheduling domains to ensure the information is propagated properly. > + */ > + if (topology_scale_freq_invariant() == status) { > + scale_freq_invariant = status; > + rebuild_sched_domains_energy(); > + } > +} > + > void topology_set_scale_freq_source(struct scale_freq_data *data, > const struct cpumask *cpus) > { > @@ -50,6 +68,8 @@ void topology_set_scale_freq_source(struct scale_freq_data *data, > cpumask_set_cpu(cpu, &scale_freq_counters_mask); > } > } Small(ish) optimisation at the beginning of this function: if (cpumask_empty(&scale_freq_counters_mask)) scale_freq_invariant = topology_scale_freq_invariant(); This will save you a call to rebuild_sched_domains_energy(), which is quite expensive, when cpufreq supports FIE and we also have counters. After comments addressed, Reviewed-by: Ionela Voinescu Tested-by: Ionela Voinescu ..for 1/2 and this addition. Thanks, Ionela. > + > + update_scale_freq_invariant(true); > } > EXPORT_SYMBOL_GPL(topology_set_scale_freq_source); > > @@ -67,6 +87,8 @@ void topology_clear_scale_freq_source(enum scale_freq_source source, > cpumask_clear_cpu(cpu, &scale_freq_counters_mask); > } > } > + > + update_scale_freq_invariant(false); > } > EXPORT_SYMBOL_GPL(topology_clear_scale_freq_source); > > -- > 2.25.0.rc1.19.g042ed3e048af > > -- > viresh