From 46bcfad7a819bd17ac4e831b04405152d59784ab Mon Sep 17 00:00:00 2001 From: Deepthi Dharwar Date: Fri, 28 Oct 2011 16:20:42 +0530 Subject: cpuidle: Single/Global registration of idle states This patch makes the cpuidle_states structure global (single copy) instead of per-cpu. The statistics needed on per-cpu basis by the governor are kept per-cpu. This simplifies the cpuidle subsystem as state registration is done by single cpu only. Having single copy of cpuidle_states saves memory. Rare case of asymmetric C-states can be handled within the cpuidle driver and architectures such as POWER do not have asymmetric C-states. Having single/global registration of all the idle states, dynamic C-state transitions on x86 are handled by the boot cpu. Here, the boot cpu would disable all the devices, re-populate the states and later enable all the devices, irrespective of the cpu that would receive the notification first. Reference: https://lkml.org/lkml/2011/4/25/83 Signed-off-by: Deepthi Dharwar Signed-off-by: Trinabh Gupta Tested-by: Jean Pihet Reviewed-by: Kevin Hilman Acked-by: Arjan van de Ven Acked-by: Kevin Hilman Signed-off-by: Len Brown --- drivers/acpi/processor_driver.c | 20 +++----------------- 1 file changed, 3 insertions(+), 17 deletions(-) (limited to 'drivers/acpi/processor_driver.c') diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c index a4e0f1ba6040..9d7bc9f6b6cc 100644 --- a/drivers/acpi/processor_driver.c +++ b/drivers/acpi/processor_driver.c @@ -426,7 +426,7 @@ static int acpi_cpu_soft_notify(struct notifier_block *nfb, if (action == CPU_ONLINE && pr) { acpi_processor_ppc_has_changed(pr, 0); - acpi_processor_cst_has_changed(pr); + acpi_processor_hotplug(pr); acpi_processor_reevaluate_tstate(pr, action); acpi_processor_tstate_has_changed(pr); } @@ -503,8 +503,7 @@ static int __cpuinit acpi_processor_add(struct acpi_device *device) acpi_processor_get_throttling_info(pr); acpi_processor_get_limit_info(pr); - - if (cpuidle_get_driver() == &acpi_idle_driver) + if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver) acpi_processor_power_init(pr, device); pr->cdev = thermal_cooling_device_register("Processor", device, @@ -800,17 +799,9 @@ static int __init acpi_processor_init(void) memset(&errata, 0, sizeof(errata)); - if (!cpuidle_register_driver(&acpi_idle_driver)) { - printk(KERN_DEBUG "ACPI: %s registered with cpuidle\n", - acpi_idle_driver.name); - } else { - printk(KERN_DEBUG "ACPI: acpi_idle yielding to %s\n", - cpuidle_get_driver()->name); - } - result = acpi_bus_register_driver(&acpi_processor_driver); if (result < 0) - goto out_cpuidle; + return result; acpi_processor_install_hotplug_notify(); @@ -821,11 +812,6 @@ static int __init acpi_processor_init(void) acpi_processor_throttling_init(); return 0; - -out_cpuidle: - cpuidle_unregister_driver(&acpi_idle_driver); - - return result; } static void __exit acpi_processor_exit(void) -- cgit v1.2.3