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authorStratos Karafotis <stratosk@semaphore.gr>2013-03-05 22:06:29 +0000
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-04-01 01:11:35 +0200
commit7af1c0568d33339318c6710381921a3a3d40eebb (patch)
tree4ae1c0bf763b140695e8efa0174e8453f9986ca7 /drivers/cpufreq/cpufreq_conservative.c
parentcpufreq: governors: Calculate iowait time only when necessary (diff)
downloadlinux-dev-7af1c0568d33339318c6710381921a3a3d40eebb.tar.xz
linux-dev-7af1c0568d33339318c6710381921a3a3d40eebb.zip
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>
Diffstat (limited to 'drivers/cpufreq/cpufreq_conservative.c')
-rw-r--r--drivers/cpufreq/cpufreq_conservative.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c
index 52f76b19a883..d746d6abbca8 100644
--- a/drivers/cpufreq/cpufreq_conservative.c
+++ b/drivers/cpufreq/cpufreq_conservative.c
@@ -36,9 +36,9 @@ static DEFINE_PER_CPU(struct cs_cpu_dbs_info_s, cs_cpu_dbs_info);
/*
* 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 @@ static void cs_check_cpu(int cpu, unsigned int load)
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