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authorAnton Blanchard <anton@samba.org>2017-04-03 23:54:12 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2017-04-19 23:17:18 +0200
commit79b578111febef642143669254b243ffbcf64ea9 (patch)
treeb48a6b2d200392ee6103da2388bbb6676443f942 /drivers/cpuidle
parentcpuidle: cpuidle-cps: remove unused variable (diff)
downloadlinux-79b578111febef642143669254b243ffbcf64ea9.tar.xz
linux-79b578111febef642143669254b243ffbcf64ea9.zip
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 <anton@samba.org> Reviewed-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpuidle')
-rw-r--r--drivers/cpuidle/cpuidle-powernv.c1
1 files changed, 0 insertions, 1 deletions
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;