From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752733AbaCAApC (ORCPT ); Fri, 28 Feb 2014 19:45:02 -0500 Received: from v094114.home.net.pl ([79.96.170.134]:64301 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752570AbaCAAo7 (ORCPT ); Fri, 28 Feb 2014 19:44:59 -0500 From: "Rafael J. Wysocki" To: Viresh Kumar Cc: skannan@codeaurora.org, linaro-kernel@lists.linaro.org, cpufreq@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, srivatsa.bhat@linux.vnet.ibm.com Subject: Re: [PATCH 1/3] cpufreq: move call to __find_governor() to cpufreq_init_policy() Date: Sat, 01 Mar 2014 02:00:03 +0100 Message-ID: <1502303.OT1VzMZkk2@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/3.13.0+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <9f9546137135103556c69815c72b81ed93cc1ca2.1393318100.git.viresh.kumar@linaro.org> References: <9f9546137135103556c69815c72b81ed93cc1ca2.1393318100.git.viresh.kumar@linaro.org> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday, February 25, 2014 02:20:09 PM Viresh Kumar wrote: > We call __find_governor() during addition of first CPU of every policy to find > the last governor used for this CPU before it was hotplugged-out. > > After that we call cpufreq_parse_governor() in cpufreq_init_policy() either with > this governor or default governor. And right after that policy->governor is set > to NULL. This is a problem, right? So care to write *why* it is a problem here? > So, instead of doing this move the relevant parts to cpufreq_init_policy() > policy only and initialize policy->governor to NULL at the beginning. And this change is supposed to fix that problem, right? You're not moving stuff around just for the fun of it? > Signed-off-by: Viresh Kumar > > --- > > Hi Saravana, > > I hope only the first two patches would fix things for you but probably you can > test all three. > > @Rafael: We might need to get these in next rc only as these are more or less > fixes. > > drivers/cpufreq/cpufreq.c | 34 ++++++++++++++++------------------ > 1 file changed, 16 insertions(+), 18 deletions(-) > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > index c755b5f..cc4f244 100644 > --- a/drivers/cpufreq/cpufreq.c > +++ b/drivers/cpufreq/cpufreq.c > @@ -879,18 +879,27 @@ err_out_kobj_put: > > static void cpufreq_init_policy(struct cpufreq_policy *policy) > { > + struct cpufreq_governor *gov = NULL; > struct cpufreq_policy new_policy; > int ret = 0; > > memcpy(&new_policy, policy, sizeof(*policy)); > > + /* Update governor of new_policy to the governor used before hotplug */ > +#ifdef CONFIG_HOTPLUG_CPU > + gov = __find_governor(per_cpu(cpufreq_cpu_governor, policy->cpu)); > +#endif > + if (gov) > + pr_debug("Restoring governor %s for cpu %d\n", > + policy->governor->name, policy->cpu); > + else > + gov = CPUFREQ_DEFAULT_GOVERNOR; > + > + new_policy.governor = gov; > + > /* Use the default policy if its valid. */ > if (cpufreq_driver->setpolicy) > - cpufreq_parse_governor(policy->governor->name, > - &new_policy.policy, NULL); > - > - /* assure that the starting sequence is run in cpufreq_set_policy */ > - policy->governor = NULL; > + cpufreq_parse_governor(gov->name, &new_policy.policy, NULL); > > /* set default policy */ > ret = cpufreq_set_policy(policy, &new_policy); > @@ -944,11 +953,11 @@ static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu) > unsigned long flags; > > read_lock_irqsave(&cpufreq_driver_lock, flags); > - > policy = per_cpu(cpufreq_cpu_data_fallback, cpu); > - > read_unlock_irqrestore(&cpufreq_driver_lock, flags); > > + policy->governor = NULL; > + > return policy; > } > > @@ -1036,7 +1045,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, > unsigned long flags; > #ifdef CONFIG_HOTPLUG_CPU > struct cpufreq_policy *tpolicy; > - struct cpufreq_governor *gov; > #endif > > if (cpu_is_offline(cpu)) > @@ -1094,7 +1102,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, > else > policy->cpu = cpu; > > - policy->governor = CPUFREQ_DEFAULT_GOVERNOR; > cpumask_copy(policy->cpus, cpumask_of(cpu)); > > init_completion(&policy->kobj_unregister); > @@ -1179,15 +1186,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, > blocking_notifier_call_chain(&cpufreq_policy_notifier_list, > CPUFREQ_START, policy); > > -#ifdef CONFIG_HOTPLUG_CPU > - gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); > - if (gov) { > - policy->governor = gov; > - pr_debug("Restoring governor %s for cpu %d\n", > - policy->governor->name, cpu); > - } > -#endif > - > if (!frozen) { > ret = cpufreq_add_dev_interface(policy, dev); > if (ret) > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.