tree b136302efccd407ef4ee608de40042bedd0ab660
parent 3611dfb8eda847c1c8e1a052f57206f7fddc6a7c
author Peter Zijlstra <a.p.zijlstra@chello.nl> 1241801541 +0200
committer Ingo Molnar <mingo@elte.hu> 1241807817 +0200

perf_counter: optimize perf_counter_task_tick()

perf_counter_task_tick() does way too much work to find out
there's nothing to do. Provide an easy short-circuit for the
normal case where there are no counters on the system.

[ Impact: micro-optimization ]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090508170028.750619201@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>