From 79b578111febef642143669254b243ffbcf64ea9 Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Tue, 4 Apr 2017 07:54:12 +1000 Subject: [PATCH] cpuidle: powernv: Don't bounce between low and very low thread priority The core of snooze_loop() continually bounces between low and very low thread priority. Changing thread priorities is an expensive operation that can negatively impact other threads on a core. All CPUs that can run PowerNV support very low priority, so we can avoid the change completely. Signed-off-by: Anton Blanchard Reviewed-by: Vaidyanathan Srinivasan Signed-off-by: Rafael J. Wysocki --- drivers/cpuidle/cpuidle-powernv.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c index a06df51a36c0..0ddf1a5bb0a9 100644 --- a/drivers/cpuidle/cpuidle-powernv.c +++ b/drivers/cpuidle/cpuidle-powernv.c @@ -57,7 +57,6 @@ static int snooze_loop(struct cpuidle_device *dev, snooze_exit_time = get_tb() + snooze_timeout; ppc64_runlatch_off(); while (!need_resched()) { - HMT_low(); HMT_very_low(); if (snooze_timeout_en && get_tb() > snooze_exit_time) break; -- 2.20.1