Currently update_sampling_rate() runs over each online CPU and cancels/queues timers on all policy->cpus every time. This should be done just once for any cpu belonging to a policy.
Create a cpumask and keep on clearing it as and when we process policies, so that we don't have to traverse through all CPUs of the same policy.
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/cpufreq/cpufreq_ondemand.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c index f879012cf849..eae51070c034 100644 --- a/drivers/cpufreq/cpufreq_ondemand.c +++ b/drivers/cpufreq/cpufreq_ondemand.c @@ -246,6 +246,7 @@ static void update_sampling_rate(struct dbs_data *dbs_data, unsigned int new_rate) { struct od_dbs_tuners *od_tuners = dbs_data->tuners; + struct cpumask cpumask; int cpu;
od_tuners->sampling_rate = new_rate = max(new_rate, @@ -256,7 +257,9 @@ static void update_sampling_rate(struct dbs_data *dbs_data, */ mutex_lock(&od_dbs_cdata.mutex);
- for_each_online_cpu(cpu) { + cpumask_copy(&cpumask, cpu_online_mask); + + for_each_cpu(cpu, &cpumask) { struct cpufreq_policy *policy; struct od_cpu_dbs_info_s *dbs_info; struct cpu_dbs_info *cdbs; @@ -276,6 +279,9 @@ static void update_sampling_rate(struct dbs_data *dbs_data,
policy = shared->policy;
+ /* clear all CPUs of this policy */ + cpumask_andnot(&cpumask, &cpumask, policy->cpus); + /* * Update sampling rate for CPUs whose policy is governed by * dbs_data. In case of governor_per_policy, only a single @@ -285,6 +291,10 @@ static void update_sampling_rate(struct dbs_data *dbs_data, if (dbs_data != policy->governor_data) continue;
+ /* + * Checking this for any CPU should be fine, timers for all of + * them are scheduled together. + */ next_sampling = jiffies + usecs_to_jiffies(new_rate); appointed_at = dbs_info->cdbs.timer.expires;