From 3a4a0042228a854d9b1073050620820b4a977e6e Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 12 Feb 2020 00:02:30 +0100 Subject: PM: QoS: Drop PM_QOS_CPU_DMA_LATENCY notifier chain Notice that pm_qos_remove_notifier() is not used at all and the only caller of pm_qos_add_notifier() is the cpuidle core, which only needs the PM_QOS_CPU_DMA_LATENCY notifier to invoke wake_up_all_idle_cpus() upon changes of the PM_QOS_CPU_DMA_LATENCY target value. First, to ensure that wake_up_all_idle_cpus() will be called whenever the PM_QOS_CPU_DMA_LATENCY target value changes, modify the pm_qos_add/update/remove_request() family of functions to check if the effective constraint for the PM_QOS_CPU_DMA_LATENCY has changed and call wake_up_all_idle_cpus() directly in that case. Next, drop the PM_QOS_CPU_DMA_LATENCY notifier from cpuidle as it is not necessary any more. Finally, drop both pm_qos_add_notifier() and pm_qos_remove_notifier(), as they have no callers now, along with cpu_dma_lat_notifier which is only used by them. Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Reviewed-by: Amit Kucheria Tested-by: Amit Kucheria --- drivers/cpuidle/cpuidle.c | 40 +--------------------------------------- 1 file changed, 1 insertion(+), 39 deletions(-) (limited to 'drivers/cpuidle') diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index de81298051b3..c149d9e20dfd 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -736,53 +736,15 @@ int cpuidle_register(struct cpuidle_driver *drv, } EXPORT_SYMBOL_GPL(cpuidle_register); -#ifdef CONFIG_SMP - -/* - * This function gets called when a part of the kernel has a new latency - * requirement. This means we need to get all processors out of their C-state, - * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that - * wakes them all right up. - */ -static int cpuidle_latency_notify(struct notifier_block *b, - unsigned long l, void *v) -{ - wake_up_all_idle_cpus(); - return NOTIFY_OK; -} - -static struct notifier_block cpuidle_latency_notifier = { - .notifier_call = cpuidle_latency_notify, -}; - -static inline void latency_notifier_init(struct notifier_block *n) -{ - pm_qos_add_notifier(PM_QOS_CPU_DMA_LATENCY, n); -} - -#else /* CONFIG_SMP */ - -#define latency_notifier_init(x) do { } while (0) - -#endif /* CONFIG_SMP */ - /** * cpuidle_init - core initializer */ static int __init cpuidle_init(void) { - int ret; - if (cpuidle_disabled()) return -ENODEV; - ret = cpuidle_add_interface(cpu_subsys.dev_root); - if (ret) - return ret; - - latency_notifier_init(&cpuidle_latency_notifier); - - return 0; + return cpuidle_add_interface(cpu_subsys.dev_root); } module_param(off, int, 0444); -- cgit v1.2.3