perf_counter: hook up the tracepoint events

Impact: new perfcounters feature

Enable usage of tracepoints as perf counter events.

tracepoint event ids can be found in /debug/tracing/event/*/*/id
and (for now) are represented as -65536+id in the type field.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Orig-LKML-Reference: <20090319194233.744044174@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

include/linux/perf_counter.h

@@ -53,6 +53,8 @@ enum hw_event_types {
 	PERF_COUNT_PAGE_FAULTS_MAJ	= -7,
 
 	PERF_SW_EVENTS_MIN		= -8,
+
+	PERF_TP_EVENTS_MIN		= -65536
 };
 
 /*
@@ -222,6 +224,7 @@ struct perf_counter {
 	struct perf_data		*usrdata;
 	struct perf_data		data[2];
 
+	void (*destroy)(struct perf_counter *);
 	struct rcu_head			rcu_head;
 #endif
 };