cpufreq: conservative: Fix sampling_down_factor functionality
sampling_down_factor tunable is unused since commit
8e677ce83bf41ba9c74e5b6d9ee60b07d4e5ed93 (4 years ago).
This patch restores the original functionality and documents the
tunable.
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_conservative.c b/drivers/cpufreq/cpufreq_conservative.c
index 52f76b1..d746d6a 100644
--- a/drivers/cpufreq/cpufreq_conservative.c
+++ b/drivers/cpufreq/cpufreq_conservative.c
@@ -36,9 +36,9 @@
/*
* Every sampling_rate, we check, if current idle time is less than 20%
- * (default), then we try to increase frequency Every sampling_rate *
- * sampling_down_factor, we check, if current idle time is more than 80%, then
- * we try to decrease frequency
+ * (default), then we try to increase frequency. Every sampling_rate *
+ * sampling_down_factor, we check, if current idle time is more than 80%
+ * (default), then we try to decrease frequency
*
* Any frequency increase takes it to the maximum frequency. Frequency reduction
* happens at minimum steps of 5% (default) of maximum frequency
@@ -81,6 +81,11 @@
return;
}
+ /* if sampling_down_factor is active break out early */
+ if (++dbs_info->down_skip < cs_tuners->sampling_down_factor)
+ return;
+ dbs_info->down_skip = 0;
+
/*
* The optimal frequency is the frequency that is the lowest that can
* support the current CPU usage without triggering the up policy. To be