diff options
| author | Anton Blanchard <anton@samba.org> | 2017-04-04 07:54:14 +1000 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2017-04-19 23:17:19 +0200 |
| commit | 0baa91cb73e296242edad89cfe3f60c59ab8a95a (patch) | |
| tree | 9e5250def7c919e0a8ad2763d7707a3dfc42bd7d /drivers/cpuidle | |
| parent | 26eb48a9faf241abd60aa546e6beb896011667c1 (diff) | |
| download | op-kernel-dev-0baa91cb73e296242edad89cfe3f60c59ab8a95a.zip op-kernel-dev-0baa91cb73e296242edad89cfe3f60c59ab8a95a.tar.gz | |
cpuidle: powernv: Avoid a branch in the core snooze_loop() loop
When in the snooze_loop() we want to take up the least amount of
resources. On my version of gcc (6.3), we end up with an extra
branch because it predicts snooze_timeout_en to be false, whereas it
is almost always true.
Use likely() to avoid the branch and be a little nicer to the
other non idle threads on the core.
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.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c index f890167..5bb4bb3 100644 --- a/drivers/cpuidle/cpuidle-powernv.c +++ b/drivers/cpuidle/cpuidle-powernv.c @@ -58,7 +58,7 @@ static int snooze_loop(struct cpuidle_device *dev, ppc64_runlatch_off(); HMT_very_low(); while (!need_resched()) { - if (snooze_timeout_en && get_tb() > snooze_exit_time) + if (likely(snooze_timeout_en) && get_tb() > snooze_exit_time) break; } |
