From 5bb1729cbdfbe974ad6385be94b14afbac97e19f Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sat, 16 Jan 2016 00:56:34 +0100 Subject: [PATCH] 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 Acked-by: Ingo Molnar Tested-by: Sudeep Holla --- drivers/cpuidle/governors/menu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c index be0bae0..0742b32 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]; -- 2.7.4