[PATCH V4 04/14] cpufreq: Don't traverse all active policies to find policy for a cpu

[Viresh Kumar <viresh.kumar@linaro.org>]

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>
---
V4->V5:
- Rebased on top of [V4 1/14]

 drivers/cpufreq/cpufreq.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index eb0c3a802b14..e6a63d6ba6f1 100644
--- 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
-- 
2.4.0