timer stats: speedups
commitc1a834dc704763673df10282995257f2de93cbe9
authorIngo Molnar <mingo@elte.hu>
Fri, 1 Jun 2007 07:47:16 +0000 (1 00:47 -0700)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>
Fri, 1 Jun 2007 15:18:30 +0000 (1 08:18 -0700)
tree66a0bc5ffbf6732eaa5fc6f554c13b235005c4cd
parent9fcc15ec3c1c287a781a4620e52522b6186f26f6
timer stats: speedups

Make timer-stats have almost zero overhead when enabled in the config but
not used.  (this way distros can enable it more easily)

Also update the documentation about overhead of timer_stats - it was
written for the first version which had a global lock and a linear list
walk based lookup ;-)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Documentation/hrtimer/timer_stats.txt
kernel/time/timer_stats.c
lib/Kconfig.debug