Commits
Peter Zijlstra committed 10b033d434c
sched/clock, x86: Avoid a runtime condition in native_sched_clock()
Use a static_key to avoid touching tsc_disabled and a runtime
condition in native_sched_clock() -- less cachelines touched is always
better.
MAINLINE PRE POST
sched_clock_stable: 1 1 1
(cold) sched_clock: 329841 215295 213039
(cold) local_clock: 301773 220773 216084
(warm) sched_clock: 38375 25659 25231
(warm) local_clock: 100371 27242 27601
(warm) rdtsc: 27340 24208 24203
sched_clock_stable: 0 0 0
(cold) sched_clock: 382634 237019 240055
(cold) local_clock: 396890 294819 299942
(warm) sched_clock: 38194 25609 25276
(warm) local_clock: 143452 71232 73232
(warm) rdtsc: 27345 24243 24244
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-hrz87bo37qke25bty6pnfy4b@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>