[PATCH 9/9] cpufreq: governor: Use microseconds in sample delay computations
From: Rafael J. Wysocki
Date: Sun Feb 14 2016 - 20:23:03 EST
From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
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@xxxxxxxxx>
---
drivers/cpufreq/cpufreq_conservative.c | 2 +-
drivers/cpufreq/cpufreq_governor.c | 4 +---
drivers/cpufreq/cpufreq_governor.h | 15 ++-------------
drivers/cpufreq/cpufreq_ondemand.c | 28 +++++++++++++---------------
4 files changed, 17 insertions(+), 32 deletions(-)
Index: linux-pm/drivers/cpufreq/cpufreq_governor.h
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq_governor.h
+++ linux-pm/drivers/cpufreq/cpufreq_governor.h
@@ -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: linux-pm/drivers/cpufreq/cpufreq_conservative.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq_conservative.c
+++ linux-pm/drivers/cpufreq/cpufreq_conservative.c
@@ -102,7 +102,7 @@ static unsigned int cs_dbs_timer(struct
}
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: linux-pm/drivers/cpufreq/cpufreq_ondemand.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq_ondemand.c
+++ linux-pm/drivers/cpufreq/cpufreq_ondemand.c
@@ -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_bi
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_bi
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_bi
/* 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
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
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 ************************/
Index: linux-pm/drivers/cpufreq/cpufreq_governor.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq_governor.c
+++ linux-pm/drivers/cpufreq/cpufreq_governor.c
@@ -282,7 +282,6 @@ static void dbs_work_handler(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
* 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. */