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cpuidle: menu: Call nr_iowait_cpu less times

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menu_select() via inline functions calls nr_iowait_cpu() twice as much
as necessary.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Mel Gorman 2014-08-06 14:19:20 +01:00 committed by Rafael J. Wysocki
parent 107d4f4601
commit 64b4ca5cb6
1 changed files with 8 additions and 7 deletions
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15
drivers/cpuidle/governors/menu.c
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@ -142,7 +142,7 @@ static int get_loadavg(void)
return LOAD_INT(this) * 10 + LOAD_FRAC(this) / 10;
}
static inline int which_bucket(unsigned int duration)
static inline int which_bucket(unsigned int duration, unsigned long nr_iowaiters)
{
int bucket = 0;
@ -152,7 +152,7 @@ static inline int which_bucket(unsigned int duration)
* This allows us to calculate
* E(duration)|iowait
*/
if (nr_iowait_cpu(smp_processor_id()))
if (nr_iowaiters)
bucket = BUCKETS/2;
if (duration < 10)
@ -175,7 +175,7 @@ static inline int which_bucket(unsigned int duration)
* to be, the higher this multiplier, and thus the higher
* the barrier to go to an expensive C state.
*/
static inline int performance_multiplier(void)
static inline int performance_multiplier(unsigned long nr_iowaiters)
{
int mult = 1;
@ -184,7 +184,7 @@ static inline int performance_multiplier(void)
mult += 2 * get_loadavg();
/* for IO wait tasks (per cpu!) we add 5x each */
mult += 10 * nr_iowait_cpu(smp_processor_id());
mult += 10 * nr_iowaiters;
return mult;
}
@ -296,6 +296,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
int latency_req = pm_qos_request(PM_QOS_CPU_DMA_LATENCY);
int i;
unsigned int interactivity_req;
unsigned long nr_iowaiters;
if (data->needs_update) {
menu_update(drv, dev);
@ -311,8 +312,8 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
/* determine the expected residency time, round up */
data->next_timer_us = ktime_to_us(tick_nohz_get_sleep_length());
data->bucket = which_bucket(data->next_timer_us);
nr_iowaiters = nr_iowait_cpu(smp_processor_id());
data->bucket = which_bucket(data->next_timer_us, nr_iowaiters);
/*
* Force the result of multiplication to be 64 bits even if both
@ -330,7 +331,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
* duration / latency ratio. Adjust the latency limit if
* necessary.
*/
interactivity_req = data->predicted_us / performance_multiplier();
interactivity_req = data->predicted_us / performance_multiplier(nr_iowaiters);
if (latency_req > interactivity_req)
latency_req = interactivity_req;