From 218a06a79d9a98a96ef46bb003d4d8adb0962056 Mon Sep 17 00:00:00 2001 From: Jie Zhan Date: Tue, 22 Aug 2023 20:48:37 +0800 Subject: [PATCH] cpufreq: Support per-policy performance boost The boost control currently applies to the whole system. However, users may prefer to boost a subset of cores in order to provide prioritized performance to workloads running on the boosted cores. Enable per-policy boost by adding a 'boost' sysfs interface under each policy path. This can be found at: /sys/devices/system/cpu/cpufreq/policy<*>/boost Same to the global boost switch, writing 1/0 to the per-policy 'boost' enables/disables boost on a cpufreq policy respectively. The user view of global and per-policy boost controls should be: 1. Enabling global boost initially enables boost on all policies, and per-policy boost can then be enabled or disabled individually, given that the platform does support so. 2. Disabling global boost makes the per-policy boost interface illegal. Signed-off-by: Jie Zhan Reviewed-by: Wei Xu Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/cpufreq.c | 43 +++++++++++++++++++++++++++++++++++++++++++ include/linux/cpufreq.h | 3 +++ 2 files changed, 46 insertions(+) diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index d9eb036..60ed890 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -86,6 +86,7 @@ static void cpufreq_governor_limits(struct cpufreq_policy *policy); static int cpufreq_set_policy(struct cpufreq_policy *policy, struct cpufreq_governor *new_gov, unsigned int new_pol); +static bool cpufreq_boost_supported(void); /* * Two notifier lists: the "policy" list is involved in the @@ -623,6 +624,40 @@ static ssize_t store_boost(struct kobject *kobj, struct kobj_attribute *attr, } define_one_global_rw(boost); +static ssize_t show_local_boost(struct cpufreq_policy *policy, char *buf) +{ + return sysfs_emit(buf, "%d\n", policy->boost_enabled); +} + +static ssize_t store_local_boost(struct cpufreq_policy *policy, + const char *buf, size_t count) +{ + int ret, enable; + + ret = kstrtoint(buf, 10, &enable); + if (ret || enable < 0 || enable > 1) + return -EINVAL; + + if (!cpufreq_driver->boost_enabled) + return -EINVAL; + + if (policy->boost_enabled == enable) + return count; + + cpus_read_lock(); + ret = cpufreq_driver->set_boost(policy, enable); + cpus_read_unlock(); + + if (ret) + return ret; + + policy->boost_enabled = enable; + + return count; +} + +static struct freq_attr local_boost = __ATTR(boost, 0644, show_local_boost, store_local_boost); + static struct cpufreq_governor *find_governor(const char *str_governor) { struct cpufreq_governor *t; @@ -1057,6 +1092,12 @@ static int cpufreq_add_dev_interface(struct cpufreq_policy *policy) return ret; } + if (cpufreq_boost_supported()) { + ret = sysfs_create_file(&policy->kobj, &local_boost.attr); + if (ret) + return ret; + } + return 0; } @@ -2718,6 +2759,8 @@ int cpufreq_boost_trigger_state(int state) ret = cpufreq_driver->set_boost(policy, state); if (ret) goto err_reset_state; + + policy->boost_enabled = state; } cpus_read_unlock(); diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 43b363a..71d186d 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -141,6 +141,9 @@ struct cpufreq_policy { */ bool dvfs_possible_from_any_cpu; + /* Per policy boost enabled flag. */ + bool boost_enabled; + /* Cached frequency lookup from cpufreq_driver_resolve_freq. */ unsigned int cached_target_freq; unsigned int cached_resolved_idx; -- 2.7.4