Register a DEV_PM_QOS_RESUME_LATENCY notifier for each CPU device and bump only that CPU's latency_req generation when its resume latency constraint changes.
Signed-off-by: Yaxiong Tian <[email protected]> --- drivers/cpuidle/cpuidle.c | 15 +++++++++--- drivers/cpuidle/cpuidle.h | 2 ++ drivers/cpuidle/governor.c | 48 +++++++++++++++++++++++++++++++++++++- 3 files changed, 61 insertions(+), 4 deletions(-) diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 2d2f40a2cb81..9495f904fe85 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -613,6 +613,8 @@ static void __cpuidle_unregister_device(struct cpuidle_device *dev) { struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); + cpuidle_latency_req_notifier_unregister(dev->cpu); + list_del(&dev->device_list); per_cpu(cpuidle_devices, dev->cpu) = NULL; module_put(drv->owner); @@ -661,10 +663,17 @@ static int __cpuidle_register_device(struct cpuidle_device *dev) ret = cpuidle_coupled_register_device(dev); if (ret) - __cpuidle_unregister_device(dev); - else - dev->registered = 1; + goto unreg; + + ret = cpuidle_latency_req_notifier_register(cpu); + if (ret) + goto unreg; + dev->registered = 1; + return 0; + +unreg: + __cpuidle_unregister_device(dev); return ret; } diff --git a/drivers/cpuidle/cpuidle.h b/drivers/cpuidle/cpuidle.h index 52701d9588f1..151fa9ebe483 100644 --- a/drivers/cpuidle/cpuidle.h +++ b/drivers/cpuidle/cpuidle.h @@ -25,6 +25,8 @@ extern void cpuidle_uninstall_idle_handler(void); /* governors */ extern struct cpuidle_governor *cpuidle_find_governor(const char *str); extern int cpuidle_switch_governor(struct cpuidle_governor *gov); +int cpuidle_latency_req_notifier_register(unsigned int cpu); +void cpuidle_latency_req_notifier_unregister(unsigned int cpu); /* sysfs */ diff --git a/drivers/cpuidle/governor.c b/drivers/cpuidle/governor.c index bc4a70d30c34..d286ccf19a69 100644 --- a/drivers/cpuidle/governor.c +++ b/drivers/cpuidle/governor.c @@ -27,10 +27,18 @@ 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. + * constraint. Global QoS changes invalidate every CPU; per-CPU resume + * latency changes invalidate only the affected CPU. */ static DEFINE_PER_CPU(atomic_t, latency_req_gen); +struct cpuidle_cpu_qos_nb { + struct notifier_block nb; + unsigned int cpu; +}; + +static DEFINE_PER_CPU(struct cpuidle_cpu_qos_nb, cpuidle_cpu_qos_nb); + static void cpuidle_latency_req_invalidate_cpu(unsigned int cpu) { atomic_inc(per_cpu_ptr(&latency_req_gen, cpu)); @@ -61,6 +69,44 @@ static struct notifier_block cpuidle_wakeup_qos_nb = { }; #endif +static int cpuidle_cpu_qos_notify(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct cpuidle_cpu_qos_nb *qos_nb = + container_of(nb, struct cpuidle_cpu_qos_nb, nb); + + cpuidle_latency_req_invalidate_cpu(qos_nb->cpu); + return NOTIFY_OK; +} + +int cpuidle_latency_req_notifier_register(unsigned int cpu) +{ + struct device *device = get_cpu_device(cpu); + struct cpuidle_cpu_qos_nb *qos_nb = + per_cpu_ptr(&cpuidle_cpu_qos_nb, cpu); + + if (!device) + return -ENODEV; + + qos_nb->cpu = cpu; + qos_nb->nb.notifier_call = cpuidle_cpu_qos_notify; + return dev_pm_qos_add_notifier(device, &qos_nb->nb, + DEV_PM_QOS_RESUME_LATENCY); +} + +void cpuidle_latency_req_notifier_unregister(unsigned int cpu) +{ + struct device *device = get_cpu_device(cpu); + struct cpuidle_cpu_qos_nb *qos_nb = + per_cpu_ptr(&cpuidle_cpu_qos_nb, cpu); + + if (!device) + return; + + dev_pm_qos_remove_notifier(device, &qos_nb->nb, + DEV_PM_QOS_RESUME_LATENCY); +} + static int __init cpuidle_latency_req_init(void) { int ret; -- 2.43.0
