cpufreq: governors: Avoid unnecessary per cpu timer interrupts

Following patch has introduced per cpu timers or works for ondemand and
conservative governors.

	commit 2abfa876f1117b0ab45f191fb1f82c41b1cbc8fe
	Author: Rickard Andersson <rickard.andersson@stericsson.com>
	Date:   Thu Dec 27 14:55:38 2012 +0000

	    cpufreq: handle SW coordinated CPUs

This causes additional unnecessary interrupts on all cpus when the load is
recently evaluated by any other cpu. i.e. When load is recently evaluated by cpu
x, we don't really need any other cpu to evaluate this load again for the next
sampling_rate time.

Some sort of code is present to avoid that but we are still getting timer
interrupts for all cpus. A good way of avoiding this would be to modify delays
for all cpus (policy->cpus) whenever any cpu has evaluated load.

This patch does this change and some related code cleanup.

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

1 files changed, 7 insertions, 5 deletions

diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index c90d345c636a..459f9ee39c74 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -216,7 +216,6 @@ static void od_check_cpu(int cpu, unsigned int load_freq)
 
 static void od_dbs_timer(struct work_struct *work)
 {
-	struct delayed_work *dw = to_delayed_work(work);
 	struct od_cpu_dbs_info_s *dbs_info =
 		container_of(work, struct od_cpu_dbs_info_s, cdbs.work.work);
 	unsigned int cpu = dbs_info->cdbs.cur_policy->cpu;
@@ -225,10 +224,13 @@ static void od_dbs_timer(struct work_struct *work)
 	struct dbs_data *dbs_data = dbs_info->cdbs.cur_policy->governor_data;
 	struct od_dbs_tuners *od_tuners = dbs_data->tuners;
 	int delay = 0, sample_type = core_dbs_info->sample_type;
+	bool modify_all = true;
 
 	mutex_lock(&core_dbs_info->cdbs.timer_mutex);
-	if (!need_load_eval(&core_dbs_info->cdbs, od_tuners->sampling_rate))
+	if (!need_load_eval(&core_dbs_info->cdbs, od_tuners->sampling_rate)) {
+		modify_all = false;
 		goto max_delay;
+	}
 
 	/* Common NORMAL_SAMPLE setup */
 	core_dbs_info->sample_type = OD_NORMAL_SAMPLE;
@@ -250,7 +252,7 @@ max_delay:
 		delay = delay_for_sampling_rate(od_tuners->sampling_rate
 				* core_dbs_info->rate_mult);
 
-	schedule_delayed_work_on(smp_processor_id(), dw, delay);
+	gov_queue_work(dbs_data, dbs_info->cdbs.cur_policy, delay, modify_all);
 	mutex_unlock(&core_dbs_info->cdbs.timer_mutex);
 }
 
@@ -310,8 +312,8 @@ static void update_sampling_rate(struct dbs_data *dbs_data,
 			cancel_delayed_work_sync(&dbs_info->cdbs.work);
 			mutex_lock(&dbs_info->cdbs.timer_mutex);
 
-			schedule_delayed_work_on(cpu, &dbs_info->cdbs.work,
-					usecs_to_jiffies(new_rate));
+			gov_queue_work(dbs_data, dbs_info->cdbs.cur_policy,
+					usecs_to_jiffies(new_rate), true);
 
 		}
 		mutex_unlock(&dbs_info->cdbs.timer_mutex);