perf_counter: Fix dynamic irq_period logging

We call perf_adjust_freq() from perf_counter_task_tick() which
is is called under the rq->lock causing lock recursion.
However, it's no longer required to be called under the
rq->lock, so remove it from under it.

Also, fix up some related comments.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090523163012.476197912@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 2 insertions, 1 deletions

diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index c10055416dea..2f410ea2cb39 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -2559,7 +2559,8 @@ void perf_counter_munmap(unsigned long addr, unsigned long len,
 }
 
 /*
- *
+ * Log irq_period changes so that analyzing tools can re-normalize the
+ * event flow.
  */
 
 static void perf_log_period(struct perf_counter *counter, u64 period)