From aa603fc147cbc2460475461566b537d6dfd8063b Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 11 Apr 2017 00:20:41 +0200 Subject: [PATCH] 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 Acked-by: Viresh Kumar (cherry picked from commit 1b72e7fd304639f1cd49d1e11955c4974936d88c) Signed-off-by: Brendan Jackman --- include/linux/cpufreq.h | 10 +++++++++- kernel/sched/cpufreq_schedutil.c | 20 +++++++++++++------- 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;