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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2017-04-11 00:20:41 +0200
committerJoel Fernandes <joelaf@google.com>2017-09-06 20:36:47 +0000
commit3482bbea6b3e9ed685ce42a77927dfeaec0be122 (patch)
treeeda8c6b0ba0863bc8bcd049c0a0fe3738522c1fd
parentb13d0fb3390670995a7fc90f96c17542e305ca59 (diff)
BACKPORT: 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. BACKPORT: Modified to support the separate up_rate_limit_us and down_rate_limit_us (upstream just has a single rate_limit_us). Also dropped the changes for intel_pstate as there's a merge conflict. Change-Id: I62a8543879a4d8582cdcb31ebd55607705d1c8b1 Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> (cherry picked from commit 1b72e7fd304639f1cd49d1e11955c4974936d88c) Signed-off-by: Brendan Jackman <brendan.jackman@arm.com>
-rw-r--r--include/linux/cpufreq.h10
-rw-r--r--kernel/sched/cpufreq_schedutil.c20
2 files changed, 22 insertions, 8 deletions
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index b144e7445477..490d577aa144 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -119,7 +119,15 @@ struct cpufreq_policy {
bool fast_switch_possible;
bool fast_switch_enabled;
- /* Cached frequency lookup from cpufreq_driver_resolve_freq. */
+ /*
+ * 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 up_transition_delay_us;
+ unsigned int down_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 a0bcf488fb81..b90f7434e13b 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -615,7 +615,6 @@ 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 */
@@ -654,12 +653,19 @@ static int sugov_init(struct cpufreq_policy *policy)
goto stop_kthread;
}
- tunables->up_rate_limit_us = LATENCY_MULTIPLIER;
- tunables->down_rate_limit_us = LATENCY_MULTIPLIER;
- lat = policy->cpuinfo.transition_latency / NSEC_PER_USEC;
- if (lat) {
- tunables->up_rate_limit_us *= lat;
- tunables->down_rate_limit_us *= lat;
+ if (policy->up_transition_delay_us && policy->down_transition_delay_us) {
+ tunables->up_rate_limit_us = policy->up_transition_delay_us;
+ tunables->down_rate_limit_us = policy->down_transition_delay_us;
+ } else {
+ unsigned int lat;
+
+ tunables->up_rate_limit_us = LATENCY_MULTIPLIER;
+ tunables->down_rate_limit_us = LATENCY_MULTIPLIER;
+ lat = policy->cpuinfo.transition_latency / NSEC_PER_USEC;
+ if (lat) {
+ tunables->up_rate_limit_us *= lat;
+ tunables->down_rate_limit_us *= lat;
+ }
}
policy->governor_data = sg_policy;