cpufreq: Don't traverse all active policies to find policy for a cpu

We reach here while adding policy for a CPU and enter into the 'if'
block only if a policy already exists for the CPU.

As cpufreq_cpu_data is set for all policy->related_cpus now, when the
policy is first added, we can use that to find the CPU's policy instead
of traversing the list of all active policies.

Acked-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index eb0c3a8..e6a63d6 100644 (file)
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1213,16 +1213,13 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
                return 0;
 
        /* Check if this CPU already has a policy to manage it */
-       read_lock_irqsave(&cpufreq_driver_lock, flags);
-       for_each_active_policy(policy) {
-               if (cpumask_test_cpu(cpu, policy->related_cpus)) {
-                       read_unlock_irqrestore(&cpufreq_driver_lock, flags);
-                       ret = cpufreq_add_policy_cpu(policy, cpu, dev);
-                       up_read(&cpufreq_rwsem);
-                       return ret;
-               }
+       policy = per_cpu(cpufreq_cpu_data, cpu);
+       if (policy && !policy_is_inactive(policy)) {
+               WARN_ON(!cpumask_test_cpu(cpu, policy->related_cpus));
+               ret = cpufreq_add_policy_cpu(policy, cpu, dev);
+               up_read(&cpufreq_rwsem);
+               return ret;
        }
-       read_unlock_irqrestore(&cpufreq_driver_lock, flags);
 
        /*
         * Restore the saved policy when doing light-weight init and fall back