perf tools: Add support for PERF_SAMPLE_IDENTIFIER

Enable parsing of samples with sample format bit PERF_SAMPLE_IDENTIFIER.
In addition, if the kernel supports it, prefer it to selecting
PERF_SAMPLE_ID thereby allowing non-matching sample types.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1377591794-30553-8-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 86 insertions, 3 deletions

diff --git a/tools/perf/util/record.c b/tools/perf/util/record.c
index 9b5ef79..18d73aa 100644
--- a/tools/perf/util/record.c
+++ b/tools/perf/util/record.c
@@ -1,11 +1,83 @@
 #include "evlist.h"
 #include "evsel.h"
 #include "cpumap.h"
+#include "parse-events.h"
+
+typedef void (*setup_probe_fn_t)(struct perf_evsel *evsel);
+
+static int perf_do_probe_api(setup_probe_fn_t fn, int cpu, const char *str)
+{
+	struct perf_evlist *evlist;
+	struct perf_evsel *evsel;
+	int err = -EAGAIN, fd;
+
+	evlist = perf_evlist__new();
+	if (!evlist)
+		return -ENOMEM;
+
+	if (parse_events(evlist, str))
+		goto out_delete;
+
+	evsel = perf_evlist__first(evlist);
+
+	fd = sys_perf_event_open(&evsel->attr, -1, cpu, -1, 0);
+	if (fd < 0)
+		goto out_delete;
+	close(fd);
+
+	fn(evsel);
+
+	fd = sys_perf_event_open(&evsel->attr, -1, cpu, -1, 0);
+	if (fd < 0) {
+		if (errno == EINVAL)
+			err = -EINVAL;
+		goto out_delete;
+	}
+	close(fd);
+	err = 0;
+
+out_delete:
+	perf_evlist__delete(evlist);
+	return err;
+}
+
+static bool perf_probe_api(setup_probe_fn_t fn)
+{
+	const char *try[] = {"cycles:u", "instructions:u", "cpu-clock", NULL};
+	struct cpu_map *cpus;
+	int cpu, ret, i = 0;
+
+	cpus = cpu_map__new(NULL);
+	if (!cpus)
+		return false;
+	cpu = cpus->map[0];
+	cpu_map__delete(cpus);
+
+	do {
+		ret = perf_do_probe_api(fn, cpu, try[i++]);
+		if (!ret)
+			return true;
+	} while (ret == -EAGAIN && try[i]);
+
+	return false;
+}
+
+static void perf_probe_sample_identifier(struct perf_evsel *evsel)
+{
+	evsel->attr.sample_type |= PERF_SAMPLE_IDENTIFIER;
+}
+
+bool perf_can_sample_identifier(void)
+{
+	return perf_probe_api(perf_probe_sample_identifier);
+}
 
 void perf_evlist__config(struct perf_evlist *evlist,
 			struct perf_record_opts *opts)
 {
 	struct perf_evsel *evsel;
+	bool use_sample_identifier = false;
+
 	/*
 	 * Set the evsel leader links before we configure attributes,
 	 * since some might depend on this info.
@@ -16,10 +88,21 @@ void perf_evlist__config(struct perf_evlist *evlist,
 	if (evlist->cpus->map[0] < 0)
 		opts->no_inherit = true;
 
-	list_for_each_entry(evsel, &evlist->entries, node) {
+	list_for_each_entry(evsel, &evlist->entries, node)
 		perf_evsel__config(evsel, opts);
 
-		if (evlist->nr_entries > 1)
-			perf_evsel__set_sample_id(evsel);
+	if (evlist->nr_entries > 1) {
+		struct perf_evsel *first = perf_evlist__first(evlist);
+
+		list_for_each_entry(evsel, &evlist->entries, node) {
+			if (evsel->attr.sample_type == first->attr.sample_type)
+				continue;
+			use_sample_identifier = perf_can_sample_identifier();
+			break;
+		}
+		list_for_each_entry(evsel, &evlist->entries, node)
+			perf_evsel__set_sample_id(evsel, use_sample_identifier);
 	}
+
+	perf_evlist__set_id_pos(evlist);
 }