cpufreq: governor: Use microseconds in sample delay computations
authorRafael J. Wysocki <rafael.j.wysocki@intel.com>
Mon, 15 Feb 2016 01:22:13 +0000 (02:22 +0100)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Wed, 9 Mar 2016 13:41:05 +0000 (14:41 +0100)
Do not convert microseconds to jiffies and the other way around
in governor computations related to the sampling rate and sample
delay and drop delay_for_sampling_rate() which isn't of any use
then.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
drivers/cpufreq/cpufreq_conservative.c
drivers/cpufreq/cpufreq_governor.c
drivers/cpufreq/cpufreq_governor.h
drivers/cpufreq/cpufreq_ondemand.c

index 2e9040e8640c4bb67ba5b42a4643ff1ef28b9bbe..4a6f8e1ed72e276d2abda2337f68d513be8b9c4b 100644 (file)
@@ -102,7 +102,7 @@ static unsigned int cs_dbs_timer(struct cpufreq_policy *policy)
        }
 
  out:
-       return delay_for_sampling_rate(dbs_data->sampling_rate);
+       return dbs_data->sampling_rate;
 }
 
 static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
index b002c0d626ea94026002af721604b923328045d0..56dba71d1788f7ec89ee0115eb273e19e856db8c 100644 (file)
@@ -282,7 +282,6 @@ static void dbs_work_handler(struct work_struct *work)
        struct policy_dbs_info *policy_dbs;
        struct cpufreq_policy *policy;
        struct dbs_governor *gov;
-       unsigned int delay;
 
        policy_dbs = container_of(work, struct policy_dbs_info, work);
        policy = policy_dbs->policy;
@@ -293,8 +292,7 @@ static void dbs_work_handler(struct work_struct *work)
         * ondemand governor isn't updating the sampling rate in parallel.
         */
        mutex_lock(&policy_dbs->timer_mutex);
-       delay = gov->gov_dbs_timer(policy);
-       policy_dbs->sample_delay_ns = jiffies_to_nsecs(delay);
+       gov_update_sample_delay(policy_dbs, gov->gov_dbs_timer(policy));
        mutex_unlock(&policy_dbs->timer_mutex);
 
        /* Allow the utilization update handler to queue up more work. */
index f21d1e125cba690a3a4f9ed95be8f4f9cf009750..7ae0c71143fa2f5a43ebee81da5be90780df21c3 100644 (file)
@@ -163,8 +163,8 @@ struct od_cpu_dbs_info_s {
        struct cpu_dbs_info cdbs;
        struct cpufreq_frequency_table *freq_table;
        unsigned int freq_lo;
-       unsigned int freq_lo_jiffies;
-       unsigned int freq_hi_jiffies;
+       unsigned int freq_lo_delay_us;
+       unsigned int freq_hi_delay_us;
        unsigned int sample_type:1;
 };
 
@@ -223,17 +223,6 @@ struct od_ops {
        void (*freq_increase)(struct cpufreq_policy *policy, unsigned int freq);
 };
 
-static inline int delay_for_sampling_rate(unsigned int sampling_rate)
-{
-       int delay = usecs_to_jiffies(sampling_rate);
-
-       /* We want all CPUs to do sampling nearly on same jiffy */
-       if (num_online_cpus() > 1)
-               delay -= jiffies % delay;
-
-       return delay;
-}
-
 extern struct mutex dbs_data_mutex;
 unsigned int dbs_update(struct cpufreq_policy *policy);
 int cpufreq_governor_dbs(struct cpufreq_policy *policy, unsigned int event);
index cb5a097c19ea9629f4cad7f5a1a46f107bfab67b..a3ee74577404f2360bc643c948d2225d23f550a8 100644 (file)
@@ -66,8 +66,8 @@ static int should_io_be_busy(void)
 
 /*
  * Find right freq to be set now with powersave_bias on.
- * Returns the freq_hi to be used right now and will set freq_hi_jiffies,
- * freq_lo, and freq_lo_jiffies in percpu area for averaging freqs.
+ * Returns the freq_hi to be used right now and will set freq_hi_delay_us,
+ * freq_lo, and freq_lo_delay_us in percpu area for averaging freqs.
  */
 static unsigned int generic_powersave_bias_target(struct cpufreq_policy *policy,
                unsigned int freq_next, unsigned int relation)
@@ -75,7 +75,7 @@ static unsigned int generic_powersave_bias_target(struct cpufreq_policy *policy,
        unsigned int freq_req, freq_reduc, freq_avg;
        unsigned int freq_hi, freq_lo;
        unsigned int index = 0;
-       unsigned int jiffies_total, jiffies_hi, jiffies_lo;
+       unsigned int delay_hi_us;
        struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info,
                                                   policy->cpu);
        struct policy_dbs_info *policy_dbs = policy->governor_data;
@@ -84,7 +84,7 @@ static unsigned int generic_powersave_bias_target(struct cpufreq_policy *policy,
 
        if (!dbs_info->freq_table) {
                dbs_info->freq_lo = 0;
-               dbs_info->freq_lo_jiffies = 0;
+               dbs_info->freq_lo_delay_us = 0;
                return freq_next;
        }
 
@@ -107,17 +107,15 @@ static unsigned int generic_powersave_bias_target(struct cpufreq_policy *policy,
        /* Find out how long we have to be in hi and lo freqs */
        if (freq_hi == freq_lo) {
                dbs_info->freq_lo = 0;
-               dbs_info->freq_lo_jiffies = 0;
+               dbs_info->freq_lo_delay_us = 0;
                return freq_lo;
        }
-       jiffies_total = usecs_to_jiffies(dbs_data->sampling_rate);
-       jiffies_hi = (freq_avg - freq_lo) * jiffies_total;
-       jiffies_hi += ((freq_hi - freq_lo) / 2);
-       jiffies_hi /= (freq_hi - freq_lo);
-       jiffies_lo = jiffies_total - jiffies_hi;
+       delay_hi_us = (freq_avg - freq_lo) * dbs_data->sampling_rate;
+       delay_hi_us += (freq_hi - freq_lo) / 2;
+       delay_hi_us /= freq_hi - freq_lo;
+       dbs_info->freq_hi_delay_us = delay_hi_us;
        dbs_info->freq_lo = freq_lo;
-       dbs_info->freq_lo_jiffies = jiffies_lo;
-       dbs_info->freq_hi_jiffies = jiffies_hi;
+       dbs_info->freq_lo_delay_us = dbs_data->sampling_rate - delay_hi_us;
        return freq_hi;
 }
 
@@ -205,7 +203,7 @@ static unsigned int od_dbs_timer(struct cpufreq_policy *policy)
        if (sample_type == OD_SUB_SAMPLE && policy_dbs->sample_delay_ns > 0) {
                __cpufreq_driver_target(policy, dbs_info->freq_lo,
                                        CPUFREQ_RELATION_H);
-               return dbs_info->freq_lo_jiffies;
+               return dbs_info->freq_lo_delay_us;
        }
 
        od_update(policy);
@@ -213,10 +211,10 @@ static unsigned int od_dbs_timer(struct cpufreq_policy *policy)
        if (dbs_info->freq_lo) {
                /* Setup timer for SUB_SAMPLE */
                dbs_info->sample_type = OD_SUB_SAMPLE;
-               return dbs_info->freq_hi_jiffies;
+               return dbs_info->freq_hi_delay_us;
        }
 
-       return delay_for_sampling_rate(dbs_data->sampling_rate * policy_dbs->rate_mult);
+       return dbs_data->sampling_rate * policy_dbs->rate_mult;
 }
 
 /************************** sysfs interface ************************/