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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2020-02-12 02:02:30 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2020-02-13 13:26:27 +0300
commit3a4a0042228a854d9b1073050620820b4a977e6e (patch)
treec577ec4a5d53479cb9cdc7caea6b5150c6827d95 /drivers/cpuidle
parent02c92a378940ba1a46b6b7ad277f1b07f8093dbc (diff)
downloadlinux-3a4a0042228a854d9b1073050620820b4a977e6e.tar.xz
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 <rafael.j.wysocki@intel.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org> Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
Diffstat (limited to 'drivers/cpuidle')
-rw-r--r--drivers/cpuidle/cpuidle.c40
1 files changed, 1 insertions, 39 deletions
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);