tree b0eacf6002f2015c0483390619a3f874bcb7e7d2
parent dc81081b2d9a6a9d64dad1bef1e5fc9fb660e53e
author Peter Zijlstra <a.p.zijlstra@chello.nl> 1244634057 +0200
committer Ingo Molnar <mingo@elte.hu> 1244645726 +0200

perf_counter: More aggressive frequency adjustment

Also employ the overflow handler to adjust the frequency, this results
in a stable frequency in about 40~50 samples, instead of that many ticks.

This also means we can start sampling at a sample period of 1 without
running head-first into the throttle.

It relies on sched_clock() to accurately measure the time difference
between the overflow NMIs.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>