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authorStratos Karafotis <stratosk@semaphore.gr>2014-05-14 21:05:52 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-05-20 14:02:09 +0200
commit1e4988563d3c92ba756d8c86917fc1b594ebe855 (patch)
tree807afe61525fc4fb70f2e84ad6e5ff458f97652d /drivers/cpufreq/freq_table.c
parente7b453d3dd5f251f13bf4670037af70bf611d0cb (diff)
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cpufreq: Break out early when frequency equals target_freq
Many drivers keep frequencies in frequency table in ascending or descending order. When governor tries to change to policy->min or policy->max respectively then the cpufreq_frequency_table_target could return on first iteration. This will save some iteration cycles. So, break out early when a frequency in cpufreq_frequency_table equals to target one. Testing this during kernel compilation using ondemand governor with a frequency table in ascending order, the cpufreq_frequency_table_target returned early on the first iteration at about 30% of times called. 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/freq_table.c')
-rw-r--r--drivers/cpufreq/freq_table.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/cpufreq/freq_table.c b/drivers/cpufreq/freq_table.c
index 8e518c6..1632981 100644
--- a/drivers/cpufreq/freq_table.c
+++ b/drivers/cpufreq/freq_table.c
@@ -137,9 +137,13 @@ int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
i = pos - table;
if ((freq < policy->min) || (freq > policy->max))
continue;
+ if (freq == target_freq) {
+ optimal.driver_data = i;
+ break;
+ }
switch (relation) {
case CPUFREQ_RELATION_H:
- if (freq <= target_freq) {
+ if (freq < target_freq) {
if (freq >= optimal.frequency) {
optimal.frequency = freq;
optimal.driver_data = i;
@@ -152,7 +156,7 @@ int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
}
break;
case CPUFREQ_RELATION_L:
- if (freq >= target_freq) {
+ if (freq > target_freq) {
if (freq <= optimal.frequency) {
optimal.frequency = freq;
optimal.driver_data = i;
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