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| author | Peter Zijlstra <peterz@infradead.org> | 2013-11-28 19:38:42 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2014-01-13 15:13:13 +0100 |
| commit | 35af99e646c7f7ea46dc2977601e9e71a51dadd5 (patch) | |
| tree | d999820d233844278549cd826c4bfd6c7aa1ecc8 /arch/x86/kernel/tsc.c | |
| parent | ef08f0fff87630d4f67ceb09514d8b444df833f8 (diff) | |
| download | linux-stable-35af99e646c7f7ea46dc2977601e9e71a51dadd5.tar.gz linux-stable-35af99e646c7f7ea46dc2977601e9e71a51dadd5.tar.bz2 linux-stable-35af99e646c7f7ea46dc2977601e9e71a51dadd5.zip | |
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 'arch/x86/kernel/tsc.c')
| -rw-r--r-- | arch/x86/kernel/tsc.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 92b090b2b79e..53c123537245 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -822,7 +822,7 @@ static unsigned long long cyc2ns_suspend; void tsc_save_sched_clock_state(void) { - if (!sched_clock_stable) + if (!sched_clock_stable()) return; cyc2ns_suspend = sched_clock(); @@ -842,7 +842,7 @@ void tsc_restore_sched_clock_state(void) unsigned long flags; int cpu; - if (!sched_clock_stable) + if (!sched_clock_stable()) return; local_irq_save(flags); @@ -984,7 +984,7 @@ void mark_tsc_unstable(char *reason) { if (!tsc_unstable) { tsc_unstable = 1; - sched_clock_stable = 0; + clear_sched_clock_stable(); disable_sched_clock_irqtime(); pr_info("Marking TSC unstable due to %s\n", reason); /* Change only the rating, when not registered */ |