diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2013-11-28 22:38:42 +0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2014-01-13 18:13:13 +0400 |
| commit | 35af99e646c7f7ea46dc2977601e9e71a51dadd5 (patch) | |
| tree | d999820d233844278549cd826c4bfd6c7aa1ecc8 /include | |
| parent | ef08f0fff87630d4f67ceb09514d8b444df833f8 (diff) | |
| download | linux-35af99e646c7f7ea46dc2977601e9e71a51dadd5.tar.xz | |
sched/clock, x86: Use a static_key for sched_clock_stable
In order to avoid the runtime condition and variable load turn
sched_clock_stable into a static_key.
Also provide a shorter implementation of local_clock() and
cpu_clock(int) when sched_clock_stable==1.
MAINLINE PRE POST
sched_clock_stable: 1 1 1
(cold) sched_clock: 329841 221876 215295
(cold) local_clock: 301773 234692 220773
(warm) sched_clock: 38375 25602 25659
(warm) local_clock: 100371 33265 27242
(warm) rdtsc: 27340 24214 24208
sched_clock_stable: 0 0 0
(cold) sched_clock: 382634 235941 237019
(cold) local_clock: 396890 297017 294819
(warm) sched_clock: 38194 25233 25609
(warm) local_clock: 143452 71234 71232
(warm) rdtsc: 27345 24245 24243
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-eummbdechzz37mwmpags1gjr@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/sched.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index a196cb7fc6f2..a03875221663 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1994,7 +1994,9 @@ static inline void sched_clock_idle_wakeup_event(u64 delta_ns) * but then during bootup it turns out that sched_clock() * is reliable after all: */ -extern int sched_clock_stable; +extern int sched_clock_stable(void); +extern void set_sched_clock_stable(void); +extern void clear_sched_clock_stable(void); extern void sched_clock_tick(void); extern void sched_clock_idle_sleep_event(void); |