[PATCH-REBASED 1/2] tools/perf: Handle EOPNOTSUPP for sampling events

[Vineet Gupta]

This allows (with next change to perf core) for calling out in userspace
the exact reason for perf record failing when PMU doesn't support
overflow interrupts

Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxxxx>
---
 tools/perf/util/evsel.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 5d7037ef7d3b..1578e67c7357 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2372,6 +2372,13 @@ int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target,
 	 "No such device - did you specify an out-of-range profile CPU?");
 		break;
 	case EOPNOTSUPP:
+		/*
+		 * Needs to be tested ahead of precise_ip check as
+		 * that seems to be true for this case as well
+		 */
+		if (evsel->attr.sample_period != 0)
+			return scnprintf(msg, size, "%s",
+	"PMU Hardware doesn't support sampling/overflow-interrupts.");
 		if (evsel->attr.precise_ip)
 			return scnprintf(msg, size, "%s",
 	"\'precise\' request may not be supported. Try removing 'p' modifier.");
-- 
2.5.0