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authorMel Gorman <mgorman@suse.de>2014-08-06 17:19:21 +0400
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-08-06 23:17:45 +0400
commit372ba8cb46b271a7662b92cbefedee56725f6bd0 (patch)
tree536013552cd845b4eb0559dc79c023ecc426c21e /drivers/cpuidle
parent64b4ca5cb6e1a9f577588db5765dc996ddf595e1 (diff)
downloadlinux-372ba8cb46b271a7662b92cbefedee56725f6bd0.tar.xz
cpuidle: menu: Lookup CPU runqueues less
The menu governer makes separate lookups of the CPU runqueue to get load and number of IO waiters but it can be done with a single lookup. Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpuidle')
-rw-r--r--drivers/cpuidle/governors/menu.c17
1 files changed, 7 insertions, 10 deletions
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index f55d8260ec43..27702742b319 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -134,12 +134,9 @@ struct menu_device {
#define LOAD_INT(x) ((x) >> FSHIFT)
#define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
-static int get_loadavg(void)
+static inline int get_loadavg(unsigned long load)
{
- unsigned long this = this_cpu_load();
-
-
- return LOAD_INT(this) * 10 + LOAD_FRAC(this) / 10;
+ return LOAD_INT(load) * 10 + LOAD_FRAC(load) / 10;
}
static inline int which_bucket(unsigned int duration, unsigned long nr_iowaiters)
@@ -175,13 +172,13 @@ static inline int which_bucket(unsigned int duration, unsigned long nr_iowaiters
* to be, the higher this multiplier, and thus the higher
* the barrier to go to an expensive C state.
*/
-static inline int performance_multiplier(unsigned long nr_iowaiters)
+static inline int performance_multiplier(unsigned long nr_iowaiters, unsigned long load)
{
int mult = 1;
/* for higher loadavg, we are more reluctant */
- mult += 2 * get_loadavg();
+ mult += 2 * get_loadavg(load);
/* for IO wait tasks (per cpu!) we add 5x each */
mult += 10 * nr_iowaiters;
@@ -296,7 +293,7 @@ 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;
+ unsigned long nr_iowaiters, cpu_load;
if (data->needs_update) {
menu_update(drv, dev);
@@ -312,7 +309,7 @@ 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());
- nr_iowaiters = nr_iowait_cpu(smp_processor_id());
+ get_iowait_load(&nr_iowaiters, &cpu_load);
data->bucket = which_bucket(data->next_timer_us, nr_iowaiters);
/*
@@ -331,7 +328,7 @@ 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(nr_iowaiters);
+ interactivity_req = data->predicted_us / performance_multiplier(nr_iowaiters, cpu_load);
if (latency_req > interactivity_req)
latency_req = interactivity_req;