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| author | Stratos Karafotis <stratosk@semaphore.gr> | 2014-05-14 20:05:52 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2014-05-20 14:02:09 +0200 |
| commit | 1e4988563d3c92ba756d8c86917fc1b594ebe855 (patch) | |
| tree | 807afe61525fc4fb70f2e84ad6e5ff458f97652d /drivers/cpufreq | |
| parent | cpufreq: Tegra: drop wrapper around tegra_update_cpu_speed() (diff) | |
| download | linux-1e4988563d3c92ba756d8c86917fc1b594ebe855.tar.xz linux-1e4988563d3c92ba756d8c86917fc1b594ebe855.zip | |
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')
| -rw-r--r-- | drivers/cpufreq/freq_table.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/cpufreq/freq_table.c b/drivers/cpufreq/freq_table.c index 8e518c689393..1632981c4b25 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; |