[PATCH v8 4/4] perf perf_api_probe: Avoid scanning all PMUs, try software PMU first

[Ian Rogers <irogers@google.com>]

Add PMU names when geting events to probe. The first is only ever used
but by not specifying a PMU name perf_api_probe will load all the
PMUs.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/perf_api_probe.c | 27 +++++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/tools/perf/util/perf_api_probe.c b/tools/perf/util/perf_api_probe.c
index 1de3b69cdf4a..a910cde4d78b 100644
--- a/tools/perf/util/perf_api_probe.c
+++ b/tools/perf/util/perf_api_probe.c
@@ -59,10 +59,10 @@ static int perf_do_probe_api(setup_probe_fn_t fn, struct perf_cpu cpu, const cha
 
 static bool perf_probe_api(setup_probe_fn_t fn)
 {
-	const char *try[] = {"cycles:u", "instructions:u", "cpu-clock:u", NULL};
+	struct perf_pmu *pmu;
 	struct perf_cpu_map *cpus;
 	struct perf_cpu cpu;
-	int ret, i = 0;
+	int ret = 0;
 
 	cpus = perf_cpu_map__new_online_cpus();
 	if (!cpus)
@@ -70,12 +70,23 @@ static bool perf_probe_api(setup_probe_fn_t fn)
 	cpu = perf_cpu_map__cpu(cpus, 0);
 	perf_cpu_map__put(cpus);
 
-	do {
-		ret = perf_do_probe_api(fn, cpu, try[i++]);
-		if (!ret)
-			return true;
-	} while (ret == -EAGAIN && try[i]);
-
+	ret = perf_do_probe_api(fn, cpu, "software/cpu-clock/u");
+	if (!ret)
+		return true;
+
+	pmu = perf_pmus__scan_core(/*pmu=*/NULL);
+	if (pmu) {
+		const char *try[] = {"cycles", "instructions", NULL};
+		char buf[256];
+		int i = 0;
+
+		 while (ret == -EAGAIN && try[i]) {
+			snprintf(buf, sizeof(buf), "%s/%s/u", pmu->name, try[i++]);
+			ret = perf_do_probe_api(fn, cpu, buf);
+			if (!ret)
+				return true;
+		}
+	}
 	return false;
 }
 
-- 
2.49.0.777.g153de2bbd5-goog