cpufreq: Do not update related_cpus on every policy activation
authorRafael J. Wysocki <rafael.j.wysocki@intel.com>
Mon, 27 Jul 2015 21:11:44 +0000 (23:11 +0200)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tue, 28 Jul 2015 15:24:12 +0000 (17:24 +0200)
The related_cpus mask includes CPUs whose cpufreq_cpu_data per-CPU
pointers have been set the the given policy.  Since those pointers
are only set at the policy creation time and unset when the policy
is deleted, the related_cpus should not be updated between those
two operations.

For this reason, avoid updating it whenever the first of the
"related" CPUs goes online.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
drivers/cpufreq/cpufreq.c

index 9d8f8cd64e5862a5cbcb941424d8d0a94b5ca0bc..0ea4bb7237600a08d5412cce0bb66f47494b15ce 100644 (file)
@@ -1251,12 +1251,12 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
 
        down_write(&policy->rwsem);
 
-       /* related cpus should atleast have policy->cpus */
-       cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus);
-
-       /* Remember which CPUs have been present at the policy creation time. */
-       if (!recover_policy)
+       if (!recover_policy) {
+               /* related_cpus should at least include policy->cpus. */
+               cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus);
+               /* Remember CPUs present at the policy creation time. */
                cpumask_and(policy->real_cpus, policy->cpus, cpu_present_mask);
+       }
 
        /*
         * affected cpus must always be the one, which are online. We aren't