[PATCH] cpuidle: menu: Optimize bucket assignment when next_timer_ns equals KTIME_MAX
From: Zhongqiu Han
Date: Thu Apr 03 2025 - 05:29:26 EST
Directly assign the last bucket value instead of calling which_bucket()
when next_timer_ns equals KTIME_MAX, the largest possible value that
always falls into the last bucket. This avoids unnecessary calculations
and enhances performance.
Signed-off-by: Zhongqiu Han <quic_zhonhan@xxxxxxxxxxx>
---
drivers/cpuidle/governors/menu.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index 39aa0aea61c6..8fc7fbed0052 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -255,7 +255,12 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
*/
data->next_timer_ns = KTIME_MAX;
delta_tick = TICK_NSEC / 2;
- data->bucket = which_bucket(KTIME_MAX);
+ /*
+ * Assign the last bucket value directly instead of calling
+ * which_bucket(), since KTIME_MAX is the largest possible
+ * value that always falls into the last bucket.
+ */
+ data->bucket = BUCKETS - 1;
}
if (unlikely(drv->state_count <= 1 || latency_req == 0) ||
--
2.25.1