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| author | Deepthi Dharwar <deepthi@linux.vnet.ibm.com> | 2011-10-28 12:50:42 +0200 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2011-11-07 03:13:58 +0100 |
| commit | 46bcfad7a819bd17ac4e831b04405152d59784ab (patch) | |
| tree | 20041e788154d103edff2699f88d4a30320e3ee2 /drivers/cpuidle/sysfs.c | |
| parent | cpuidle: Split cpuidle_state structure and move per-cpu statistics fields (diff) | |
| download | linux-46bcfad7a819bd17ac4e831b04405152d59784ab.tar.xz 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/cpuidle/sysfs.c')
| -rw-r--r-- | drivers/cpuidle/sysfs.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c index 8a1ace104476..1e756e160dca 100644 --- a/drivers/cpuidle/sysfs.c +++ b/drivers/cpuidle/sysfs.c @@ -322,13 +322,14 @@ int cpuidle_add_state_sysfs(struct cpuidle_device *device) { int i, ret = -ENOMEM; struct cpuidle_state_kobj *kobj; + struct cpuidle_driver *drv = cpuidle_get_driver(); /* state statistics */ for (i = 0; i < device->state_count; i++) { kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL); if (!kobj) goto error_state; - kobj->state = &device->states[i]; + kobj->state = &drv->states[i]; kobj->state_usage = &device->states_usage[i]; init_completion(&kobj->kobj_unregister); |