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author | Deepthi Dharwar <deepthi@linux.vnet.ibm.com> | 2011-10-28 16:20:42 +0530 |
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committer | Len Brown <len.brown@intel.com> | 2011-11-06 21:13:58 -0500 |
commit | 46bcfad7a819bd17ac4e831b04405152d59784ab (patch) | |
tree | 20041e788154d103edff2699f88d4a30320e3ee2 /drivers/acpi/processor_driver.c | |
parent | 4202735e8ab6ecfb0381631a0d0b58fefe0bd4e2 (diff) | |
download | linux-46bcfad7a819bd17ac4e831b04405152d59784ab.tar.gz linux-46bcfad7a819bd17ac4e831b04405152d59784ab.tar.bz2 linux-46bcfad7a819bd17ac4e831b04405152d59784ab.zip |
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 <deepthi@linux.vnet.ibm.com>
Signed-off-by: Trinabh Gupta <g.trinabh@gmail.com>
Tested-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi/processor_driver.c')
-rw-r--r-- | drivers/acpi/processor_driver.c | 20 |
1 files changed, 3 insertions, 17 deletions
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) |