Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934353AbbGHIGl (ORCPT ); Wed, 8 Jul 2015 04:06:41 -0400 Received: from mail-yk0-f173.google.com ([209.85.160.173]:36185 "EHLO mail-yk0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934819AbbGHIFO (ORCPT ); Wed, 8 Jul 2015 04:05:14 -0400 MIME-Version: 1.0 In-Reply-To: References: Date: Wed, 8 Jul 2015 16:05:12 +0800 Message-ID: Subject: Re: [PATCH] cpufreq: Allow accessing freq_table for offline CPUs From: Pi-Cheng Chen To: Viresh Kumar Cc: Rafael Wysocki , Linaro Kernel Mailman List , "linux-pm@vger.kernel.org" , Zhang Rui , Eduardo Valentin , javi.merino@arm.com, open list Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3161 Lines: 82 On Wed, Jul 8, 2015 at 3:38 PM, Viresh Kumar wrote: > Users of freq table may want to access it for any CPU from > policy->related_cpus mask. One such user is cpu-cooling layer. It gets a > list of 'clip_cpus' (equivalent to policy->related_cpus) during > registration and tries to get freq_table for the first CPU of this mask. > > If the CPU, for which it tries to fetch freq_table, is offline, > cpufreq_frequency_get_table() fails. This happens because it relies on > cpufreq_cpu_get_raw() for its functioning which returns policy only for > online CPUs. > > Fix this by considering offline CPUs, but with a restriction that the > policy is active at that time. > > Because we will be using 'cpufreq_cpu_data' now, which is internal to > cpufreq-core, lets also move cpufreq_frequency_get_table() to cpufreq.c > file. > > Reported-by: Pi-Cheng Chen > Signed-off-by: Viresh Kumar Tested-by: Pi-Cheng Chen Thanks. > --- > This was recently tried by Pi cheng but in a completely different way: > http://marc.info/?l=linux-pm&m=143572367402758&w=2 > > Its not broken by any stuff in 4.2, but would be good if we can push > this for 4.2 as well. > > drivers/cpufreq/cpufreq.c | 9 +++++++++ > drivers/cpufreq/freq_table.c | 7 ------- > 2 files changed, 9 insertions(+), 7 deletions(-) > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > index 2c22e3902e72..26063afb3eba 100644 > --- a/drivers/cpufreq/cpufreq.c > +++ b/drivers/cpufreq/cpufreq.c > @@ -169,6 +169,15 @@ struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy) > } > EXPORT_SYMBOL_GPL(get_governor_parent_kobj); > > +struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu) > +{ > + struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); > + > + return policy && !policy_is_inactive(policy) ? > + policy->freq_table : NULL; > +} > +EXPORT_SYMBOL_GPL(cpufreq_frequency_get_table); > + > static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall) > { > u64 idle_time; > diff --git a/drivers/cpufreq/freq_table.c b/drivers/cpufreq/freq_table.c > index df14766a8e06..7551f01e8536 100644 > --- a/drivers/cpufreq/freq_table.c > +++ b/drivers/cpufreq/freq_table.c > @@ -299,13 +299,6 @@ EXPORT_SYMBOL_GPL(cpufreq_table_validate_and_show); > > struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu); > > -struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu) > -{ > - struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu); > - return policy ? policy->freq_table : NULL; > -} > -EXPORT_SYMBOL_GPL(cpufreq_frequency_get_table); > - > MODULE_AUTHOR("Dominik Brodowski "); > MODULE_DESCRIPTION("CPUfreq frequency table helpers"); > MODULE_LICENSE("GPL"); > -- > 2.4.0 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/