[PATCH 4/5] cpufreq: conservative: call dbs_check_cpu only when necessary
From: Fabio Baltieri <hidden>
Date: 2012-12-27 14:56:39
Also in:
lkml
Subsystem:
cpu frequency scaling framework, the rest · Maintainers:
"Rafael J. Wysocki", Viresh Kumar, Linus Torvalds
Modify conservative timer to not resample CPU utilization if recently sampled from another SW coordinated core. Signed-off-by: Fabio Baltieri <redacted> --- drivers/cpufreq/cpufreq_conservative.c | 47 +++++++++++++++++++++++++++++----- 1 file changed, 41 insertions(+), 6 deletions(-)
diff --git a/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c
index b9d7f14..5d8e894 100644
--- a/drivers/cpufreq/cpufreq_conservative.c
+++ b/drivers/cpufreq/cpufreq_conservative.c@@ -111,22 +111,57 @@ static void cs_check_cpu(int cpu, unsigned int load) } } -static void cs_dbs_timer(struct work_struct *work) +static void cs_timer_update(struct cs_cpu_dbs_info_s *dbs_info, bool sample, + struct delayed_work *dw) { - struct cs_cpu_dbs_info_s *dbs_info = container_of(work, - struct cs_cpu_dbs_info_s, cdbs.work.work); unsigned int cpu = dbs_info->cdbs.cpu; int delay = delay_for_sampling_rate(cs_tuners.sampling_rate); + if (sample) + dbs_check_cpu(&cs_dbs_data, cpu); + + schedule_delayed_work_on(smp_processor_id(), dw, delay); +} + +static void cs_timer_coordinated(struct cs_cpu_dbs_info_s *dbs_info_local, + struct delayed_work *dw) +{ + struct cs_cpu_dbs_info_s *dbs_info; + ktime_t time_now; + s64 delta_us; + bool sample = true; + + /* use leader CPU's dbs_info */ + dbs_info = &per_cpu(cs_cpu_dbs_info, dbs_info_local->cdbs.cpu); mutex_lock(&dbs_info->cdbs.timer_mutex); - dbs_check_cpu(&cs_dbs_data, cpu); + time_now = ktime_get(); + delta_us = ktime_us_delta(time_now, dbs_info->cdbs.time_stamp); - schedule_delayed_work_on(smp_processor_id(), &dbs_info->cdbs.work, - delay); + /* Do nothing if we recently have sampled */ + if (delta_us < (s64)(cs_tuners.sampling_rate / 2)) + sample = false; + else + dbs_info->cdbs.time_stamp = time_now; + + cs_timer_update(dbs_info, sample, dw); mutex_unlock(&dbs_info->cdbs.timer_mutex); } +static void cs_dbs_timer(struct work_struct *work) +{ + struct delayed_work *dw = to_delayed_work(work); + struct cs_cpu_dbs_info_s *dbs_info = container_of(work, + struct cs_cpu_dbs_info_s, cdbs.work.work); + + if (dbs_sw_coordinated_cpus(&dbs_info->cdbs)) { + cs_timer_coordinated(dbs_info, dw); + } else { + mutex_lock(&dbs_info->cdbs.timer_mutex); + cs_timer_update(dbs_info, true, dw); + mutex_unlock(&dbs_info->cdbs.timer_mutex); + } +} static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val, void *data) {
--
1.7.12.1