perf_counter: Log irq_period changes
For the dynamic irq_period code, log whenever we change the period so that
analyzing code can normalize the event flow.
[ Impact: add new feature to allow more precise profiling ]
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: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090520102553.298769743@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h
index c8c1dfc2..f612941 100644
--- a/include/linux/perf_counter.h
+++ b/include/linux/perf_counter.h
@@ -258,6 +258,14 @@
PERF_EVENT_COMM = 3,
/*
+ * struct {
+ * struct perf_event_header header;
+ * u64 irq_period;
+ * };
+ */
+ PERF_EVENT_PERIOD = 4,
+
+ /*
* When header.misc & PERF_EVENT_MISC_OVERFLOW the event_type field
* will be PERF_RECORD_*
*