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| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2017-04-11 00:20:41 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2017-04-17 18:37:27 +0200 |
| commit | 1b72e7fd304639f1cd49d1e11955c4974936d88c (patch) | |
| tree | 3e0f6a04789bd0d92410ed3e273ee1b6bdc041de | |
| parent | Merge branch 'intel_pstate' into pm-cpufreq-sched (diff) | |
| download | linux-1b72e7fd304639f1cd49d1e11955c4974936d88c.tar.xz linux-1b72e7fd304639f1cd49d1e11955c4974936d88c.zip | |
cpufreq: schedutil: Use policy-dependent transition delays
Make the schedutil governor take the initial (default) value of the
rate_limit_us sysfs attribute from the (new) transition_delay_us
policy parameter (to be set by the scaling driver).
That will allow scaling drivers to make schedutil use smaller default
values of rate_limit_us and reduce the default average time interval
between consecutive frequency changes.
Make intel_pstate set transition_delay_us to 500.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
| -rw-r--r-- | drivers/cpufreq/intel_pstate.c | 2 | ||||
| -rw-r--r-- | include/linux/cpufreq.h | 7 | ||||
| -rw-r--r-- | kernel/sched/cpufreq_schedutil.c | 15 |
3 files changed, 19 insertions, 5 deletions
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index c31b72b16c2b..b7de5bd76a31 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -41,6 +41,7 @@ #define INTEL_PSTATE_HWP_SAMPLING_INTERVAL (50 * NSEC_PER_MSEC) #define INTEL_CPUFREQ_TRANSITION_LATENCY 20000 +#define INTEL_CPUFREQ_TRANSITION_DELAY 500 #ifdef CONFIG_ACPI #include <acpi/processor.h> @@ -2237,6 +2238,7 @@ static int intel_cpufreq_cpu_init(struct cpufreq_policy *policy) return ret; policy->cpuinfo.transition_latency = INTEL_CPUFREQ_TRANSITION_LATENCY; + policy->transition_delay_us = INTEL_CPUFREQ_TRANSITION_DELAY; /* This reflects the intel_pstate_get_cpu_pstates() setting. */ policy->cur = policy->cpuinfo.min_freq; diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 87165f06a307..a5ce0bbeadb5 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -120,6 +120,13 @@ struct cpufreq_policy { bool fast_switch_possible; bool fast_switch_enabled; + /* + * Preferred average time interval between consecutive invocations of + * the driver to set the frequency for this policy. To be set by the + * scaling driver (0, which is the default, means no preference). + */ + unsigned int transition_delay_us; + /* Cached frequency lookup from cpufreq_driver_resolve_freq. */ unsigned int cached_target_freq; int cached_resolved_idx; diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index b1fedf9932d6..76877a62b5fa 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -494,7 +494,6 @@ static int sugov_init(struct cpufreq_policy *policy) { struct sugov_policy *sg_policy; struct sugov_tunables *tunables; - unsigned int lat; int ret = 0; /* State should be equivalent to EXIT */ @@ -533,10 +532,16 @@ static int sugov_init(struct cpufreq_policy *policy) goto stop_kthread; } - tunables->rate_limit_us = LATENCY_MULTIPLIER; - lat = policy->cpuinfo.transition_latency / NSEC_PER_USEC; - if (lat) - tunables->rate_limit_us *= lat; + if (policy->transition_delay_us) { + tunables->rate_limit_us = policy->transition_delay_us; + } else { + unsigned int lat; + + tunables->rate_limit_us = LATENCY_MULTIPLIER; + lat = policy->cpuinfo.transition_latency / NSEC_PER_USEC; + if (lat) + tunables->rate_limit_us *= lat; + } policy->governor_data = sg_policy; sg_policy->tunables = tunables; |