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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2010-03-06 19:49:19 +0100
committerIngo Molnar <mingo@elte.hu>2010-03-10 13:22:25 +0100
commit32975a4f114be52286f9a5bf6c230dbb8c0e1903 (patch)
treea5259dd7fb4cab05c837bace8a735a439bafc904 /kernel/perf_event.c
parent3f6da3905398826d85731247e7fbcf53400c18bd (diff)
perf: Optimize perf_disable
Currently we always call hw_perf_disable(), even if its already disabled, this seems superflous, esp. since it cannot be made NMI safe (see further patches). Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: paulus@samba.org Cc: eranian@google.com Cc: robert.richter@amd.com Cc: fweisbec@gmail.com Cc: Arnaldo Carvalho de Melo <acme@infradead.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/perf_event.c')
-rw-r--r--kernel/perf_event.c16
1 files changed, 3 insertions, 13 deletions
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 73329dedb5ad..d8108465397d 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -93,25 +93,15 @@ void __weak perf_event_print_debug(void) { }
static DEFINE_PER_CPU(int, perf_disable_count);
-void __perf_disable(void)
-{
- __get_cpu_var(perf_disable_count)++;
-}
-
-bool __perf_enable(void)
-{
- return !--__get_cpu_var(perf_disable_count);
-}
-
void perf_disable(void)
{
- __perf_disable();
- hw_perf_disable();
+ if (!__get_cpu_var(perf_disable_count)++)
+ hw_perf_disable();
}
void perf_enable(void)
{
- if (__perf_enable())
+ if (!--__get_cpu_var(perf_disable_count))
hw_perf_enable();
}