Register for CPU latency and wakeup latency QoS notifications and bump a per-CPU generation counter when either aggregate constraint changes. This prepares for caching the governor latency requirement without introducing a direct qos-to-cpuidle call dependency.
Signed-off-by: Yaxiong Tian <[email protected]> --- drivers/cpuidle/governor.c | 58 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+) diff --git a/drivers/cpuidle/governor.c b/drivers/cpuidle/governor.c index 5d0e7f78c6c5..bc4a70d30c34 100644 --- a/drivers/cpuidle/governor.c +++ b/drivers/cpuidle/governor.c @@ -8,10 +8,13 @@ * This code is licenced under the GPL. */ +#include <linux/atomic.h> #include <linux/cpu.h> #include <linux/cpuidle.h> +#include <linux/init.h> #include <linux/mutex.h> #include <linux/module.h> +#include <linux/notifier.h> #include <linux/pm_qos.h> #include "cpuidle.h" @@ -22,6 +25,61 @@ LIST_HEAD(cpuidle_governors); struct cpuidle_governor *cpuidle_curr_governor; struct cpuidle_governor *cpuidle_prev_governor; +/* + * Per-CPU generation bumped to invalidate that CPU's cached latency + * constraint. Consumers of the generation are added in later changes. + */ +static DEFINE_PER_CPU(atomic_t, latency_req_gen); + +static void cpuidle_latency_req_invalidate_cpu(unsigned int cpu) +{ + atomic_inc(per_cpu_ptr(&latency_req_gen, cpu)); +} + +static void cpuidle_latency_req_invalidate_all(void) +{ + unsigned int cpu; + + for_each_possible_cpu(cpu) + cpuidle_latency_req_invalidate_cpu(cpu); +} + +static int cpuidle_global_qos_notify(struct notifier_block *nb, + unsigned long action, void *data) +{ + cpuidle_latency_req_invalidate_all(); + return NOTIFY_OK; +} + +static struct notifier_block cpuidle_latency_qos_nb = { + .notifier_call = cpuidle_global_qos_notify, +}; + +#ifdef CONFIG_PM_QOS_CPU_SYSTEM_WAKEUP +static struct notifier_block cpuidle_wakeup_qos_nb = { + .notifier_call = cpuidle_global_qos_notify, +}; +#endif + +static int __init cpuidle_latency_req_init(void) +{ + int ret; + + ret = cpu_latency_qos_add_notifier(&cpuidle_latency_qos_nb); + if (ret) + return ret; + +#ifdef CONFIG_PM_QOS_CPU_SYSTEM_WAKEUP + ret = cpu_wakeup_latency_qos_add_notifier(&cpuidle_wakeup_qos_nb); + if (ret) { + cpu_latency_qos_remove_notifier(&cpuidle_latency_qos_nb); + return ret; + } +#endif + return 0; +} +core_initcall(cpuidle_latency_req_init); + /** * cpuidle_find_governor - finds a governor of the specified name * @str: the name -- 2.43.0
