perf: Add attr->precise support to raw event parsing

Minimal userspace interface to the new 'precise' events flag.

Can be used like "perf top -e r00c0p" which will use PEBS to sample
retired instructions.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
LKML-Reference: <20100304140100.468665803@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

tools/perf/util/parse-events.c

@@ -656,6 +656,10 @@ parse_raw_event(const char **strp, struct perf_event_attr *attr)
 		return EVT_FAILED;
 	n = hex2u64(str + 1, &config);
 	if (n > 0) {
+		if (str[n+1] == 'p') {
+			attr->precise = 1;
+			n++;
+		}
 		*strp = str + n + 1;
 		attr->type = PERF_TYPE_RAW;
 		attr->config = config;