cpufreq: ondemand: Replace down_differential tuner with adj_up_threshold
In order to avoid the calculation of up_threshold - down_differential
every time that the frequency must be decreased, we replace the
down_differential tuner with the adj_up_threshold which keeps the
difference across multiple checks.
Update the adj_up_threshold only when the up_theshold is also updated.
Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index f38b8da..09b27ae 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -47,7 +47,8 @@
static struct od_dbs_tuners od_tuners = {
.up_threshold = DEF_FREQUENCY_UP_THRESHOLD,
.sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR,
- .down_differential = DEF_FREQUENCY_DOWN_DIFFERENTIAL,
+ .adj_up_threshold = DEF_FREQUENCY_UP_THRESHOLD -
+ DEF_FREQUENCY_DOWN_DIFFERENTIAL,
.ignore_nice = 0,
.powersave_bias = 0,
};
@@ -192,11 +193,9 @@
* support the current CPU usage without triggering the up policy. To be
* safe, we focus 10 points under the threshold.
*/
- if (load_freq < (od_tuners.up_threshold - od_tuners.down_differential) *
- policy->cur) {
+ if (load_freq < od_tuners.adj_up_threshold * policy->cur) {
unsigned int freq_next;
- freq_next = load_freq / (od_tuners.up_threshold -
- od_tuners.down_differential);
+ freq_next = load_freq / od_tuners.adj_up_threshold;
/* No longer fully busy, reset rate_mult */
dbs_info->rate_mult = 1;
@@ -359,6 +358,10 @@
input < MIN_FREQUENCY_UP_THRESHOLD) {
return -EINVAL;
}
+ /* Calculate the new adj_up_threshold */
+ od_tuners.adj_up_threshold += input;
+ od_tuners.adj_up_threshold -= od_tuners.up_threshold;
+
od_tuners.up_threshold = input;
return count;
}
@@ -515,7 +518,8 @@
if (idle_time != -1ULL) {
/* Idle micro accounting is supported. Use finer thresholds */
od_tuners.up_threshold = MICRO_FREQUENCY_UP_THRESHOLD;
- od_tuners.down_differential = MICRO_FREQUENCY_DOWN_DIFFERENTIAL;
+ od_tuners.adj_up_threshold = MICRO_FREQUENCY_UP_THRESHOLD -
+ MICRO_FREQUENCY_DOWN_DIFFERENTIAL;
/*
* In nohz/micro accounting case we set the minimum frequency
* not depending on HZ, but fixed (very low). The deferred
