[PATCH 3/4] cpuidle/menu: stop seeking deeper idle if current state is too deep

From: Alex Shi
Date: Fri Aug 19 2016 - 04:25:47 EST


The obsolete commit 71abbbf85 want to introduce a dynamic cstates,
but it was removed for long time. Just left the nonsense deeper cstate
checking.

Since all target_residency and exit_latency are going longer in deeper
idle state, no needs to waste some cpu cycle on useless seeking.

Signed-off-by: Alex Shi <alex.shi@xxxxxxxxxx>
To: linux-kernel@xxxxxxxxxxxxxxx
Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Cc: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Cc: Alex Shi <alex.shi@xxxxxxxxxx>
Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx>
---
drivers/cpuidle/governors/menu.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index 03d38c2..bb58e2a 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -358,9 +358,9 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
if (s->disabled || su->disable)
continue;
if (s->target_residency > data->predicted_us)
- continue;
+ break;
if (s->exit_latency > latency_req)
- continue;
+ break;

data->last_state_idx = i;
}
--
2.8.1.101.g72d917a