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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2016-01-16 00:56:34 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2016-01-19 15:28:23 +0100
commit5bb1729cbdfbe974ad6385be94b14afbac97e19f (patch)
tree6a594c2ef4f971024f5b536c526f905a9d868f1a /drivers/cpuidle
parentsched / idle: Drop default_idle_call() fallback from call_cpuidle() (diff)
downloadlinux-5bb1729cbdfbe974ad6385be94b14afbac97e19f.tar.xz
linux-5bb1729cbdfbe974ad6385be94b14afbac97e19f.zip
cpuidle: menu: Avoid pointless checks in menu_select()
If menu_select() cannot find a suitable state to return, it will return the state index stored in data->last_state_idx. This means that it is pointless to look at the states whose indices are less than or equal to data->last_state_idx in the main loop, so don't do that. Given that those checks are done on every idle state selection, this change can save quite a bit of completely unnecessary overhead. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Ingo Molnar <mingo@kernel.org> Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Diffstat (limited to 'drivers/cpuidle')
-rw-r--r--drivers/cpuidle/governors/menu.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index be0bae0b41e9..0742b3296673 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -342,7 +342,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
* Find the idle state with the lowest power while satisfying
* our constraints.
*/
- for (i = CPUIDLE_DRIVER_STATE_START; i < drv->state_count; i++) {
+ for (i = data->last_state_idx + 1; i < drv->state_count; i++) {
struct cpuidle_state *s = &drv->states[i];
struct cpuidle_state_usage *su = &dev->states_usage[i];