[PATCH 2/3] cpufreq: Notify governors when cpus are hot-[un]plugged

Viresh Kumar
2012-12-16T05:50:09Z

Because cpufreq core and governors worry only about the online cpus, if a cpu is
hot [un]plugged, we must notify governors about it, otherwise be ready to expect
something unexpected.

We already have notifiers in the form of CPUFREQ_GOV_START/CPUFREQ_GOV_STOP, we
just need to call them now.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
drivers/cpufreq/cpufreq.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index de99517..a0a33bd 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -751,11 +751,16 @@ static int cpufreq_add_dev_policy(unsigned int cpu,
return -EBUSY;
}

+ __cpufreq_governor(managed_policy, CPUFREQ_GOV_STOP);
+
spin_lock_irqsave(&cpufreq_driver_lock, flags);
cpumask_copy(managed_policy->cpus, policy->cpus);
per_cpu(cpufreq_cpu_data, cpu) = managed_policy;
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);

+ __cpufreq_governor(managed_policy, CPUFREQ_GOV_START);
+ __cpufreq_governor(managed_policy, CPUFREQ_GOV_LIMITS);
+
pr_debug("CPU already managed, adding link\n");
ret = sysfs_create_link(&dev->kobj,
&managed_policy->kobj,
@@ -1066,8 +1071,13 @@ static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif
*/
if (unlikely(cpu != data->cpu)) {
pr_debug("removing link\n");
+ __cpufreq_governor(data, CPUFREQ_GOV_STOP);
cpumask_clear_cpu(cpu, data->cpus);
spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
+ __cpufreq_governor(data, CPUFREQ_GOV_START);
+ __cpufreq_governor(data, CPUFREQ_GOV_LIMITS);
+
kobj = &dev->kobj;
cpufreq_cpu_put(data);
unlock_policy_rwsem_write(cpu);
--
1.7.12.rc2.18.g61b472e