Currently update_sampling_rate() runs over each online CPU and cancels/queues work on it. Its very inefficient for the case where a single policy manages multiple CPUs, as they can be processed together.
Also drop the unnecessary cancel_delayed_work_sync() as we are doing a mod_delayed_work_on() in gov_queue_work(), which will take care of pending works for us.
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/cpufreq/cpufreq_ondemand.c | 32 ++++++++++++++++++++------------ 1 file changed, 20 insertions(+), 12 deletions(-)
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c index 841e1fa96ee7..cfecd3b67cb3 100644 --- a/drivers/cpufreq/cpufreq_ondemand.c +++ b/drivers/cpufreq/cpufreq_ondemand.c @@ -247,40 +247,48 @@ static void update_sampling_rate(struct dbs_data *dbs_data, unsigned int new_rate) { struct od_dbs_tuners *od_tuners = dbs_data->tuners; + struct cpufreq_policy *policy; + struct od_cpu_dbs_info_s *dbs_info; + unsigned long next_sampling, appointed_at; + struct cpumask cpumask; int cpu;
+ cpumask_copy(&cpumask, cpu_online_mask); + od_tuners->sampling_rate = new_rate = max(new_rate, dbs_data->min_sampling_rate);
- for_each_online_cpu(cpu) { - struct cpufreq_policy *policy; - struct od_cpu_dbs_info_s *dbs_info; - unsigned long next_sampling, appointed_at; - + for_each_cpu(cpu, &cpumask) { policy = cpufreq_cpu_get(cpu); if (!policy) continue; + + /* clear all CPUs of this policy */ + cpumask_andnot(&cpumask, &cpumask, policy->cpus); + if (policy->governor != &cpufreq_gov_ondemand) { cpufreq_cpu_put(policy); continue; } + dbs_info = &per_cpu(od_cpu_dbs_info, cpu); cpufreq_cpu_put(policy);
+ /* + * Checking this for any CPU of the policy is fine. As either + * all would have queued work or none. + */ if (!delayed_work_pending(&dbs_info->cdbs.dwork)) continue;
next_sampling = jiffies + usecs_to_jiffies(new_rate); appointed_at = dbs_info->cdbs.dwork.timer.expires;
- if (time_before(next_sampling, appointed_at)) { - cancel_delayed_work_sync(&dbs_info->cdbs.dwork); - - gov_queue_work(dbs_data, policy, - usecs_to_jiffies(new_rate), - cpumask_of(cpu)); + if (!time_before(next_sampling, appointed_at)) + continue;
- } + gov_queue_work(dbs_data, policy, usecs_to_jiffies(new_rate), + policy->cpus); } }