perf_counter: Optimize perf_counter_alloc()'s inherit case
authorPeter Zijlstra <a.p.zijlstra@chello.nl>
Mon, 22 Jun 2009 11:58:35 +0000 (13:58 +0200)
committerIngo Molnar <mingo@elte.hu>
Tue, 23 Jun 2009 09:42:46 +0000 (11:42 +0200)
commitf344011ccb85469445369153c3d27c4ee4bc2ac8
tree66f041a826d09c690a5e6bb3d091494d52bc8565
parentb84fbc9fb1d943e2c5f4efe52ed0e3c93a4bdb6a
perf_counter: Optimize perf_counter_alloc()'s inherit case

We don't need to add usage counts for swcounter and attr usage
models for inherited counters since the parent counter will
always have one, which suffices to generate the needed output.

This avoids up to 3 global atomic increments per inherited
counter.

LKML-Reference: <new-submission>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
kernel/perf_counter.c