perf_counter: add PERF_RECORD_CONFIG

Much like CONFIG_RECORD_GROUP records the hw_event.config to
identify the values, allow to record this for all counters.

[ Impact: extend perfcounter output record format ]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090508170028.923228280@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

include/linux/perf_counter.h

@@ -104,6 +104,7 @@ enum perf_counter_record_format {
 	PERF_RECORD_ADDR	= 1U << 3,
 	PERF_RECORD_GROUP	= 1U << 4,
 	PERF_RECORD_CALLCHAIN	= 1U << 5,
+	PERF_RECORD_CONFIG	= 1U << 6,
 };
 
 /*
@@ -258,6 +259,7 @@ enum perf_event_type {
 	 * 	{ u32			pid, tid; } && PERF_RECORD_TID
 	 * 	{ u64			time;     } && PERF_RECORD_TIME
 	 * 	{ u64			addr;     } && PERF_RECORD_ADDR
+	 * 	{ u64			config;   } && PERF_RECORD_CONFIG
 	 *
 	 * 	{ u64			nr;
 	 * 	  { u64 event, val; } 	cnt[nr];  } && PERF_RECORD_GROUP

kernel/perf_counter.c

@@ -1994,6 +1994,11 @@ static void perf_counter_output(struct perf_counter *counter,
 		header.size += sizeof(u64);
 	}
 
+	if (record_type & PERF_RECORD_CONFIG) {
+		header.type |= PERF_RECORD_CONFIG;
+		header.size += sizeof(u64);
+	}
+
 	if (record_type & PERF_RECORD_GROUP) {
 		header.type |= PERF_RECORD_GROUP;
 		header.size += sizeof(u64) +
@@ -2029,6 +2034,9 @@ static void perf_counter_output(struct perf_counter *counter,
 	if (record_type & PERF_RECORD_ADDR)
 		perf_output_put(&handle, addr);
 
+	if (record_type & PERF_RECORD_CONFIG)
+		perf_output_put(&handle, counter->hw_event.config);
+
 	/*
 	 * XXX PERF_RECORD_GROUP vs inherited counters seems difficult.
 	 */