tools/perf: Handle -EOPNOTSUPP for sampling events

This allows (with a previous change to the perf error return ABI) for
calling out in userspace the exact reason for perf record failing
when PMU doesn't support overflow interrupts.

Note that this needs to be put ahead of existing precise_ip check as
that gets hit otherwise for the sampling fail case as well.

Signed-off-by: Vineet Gupta <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vince Weaver <[email protected]>
Cc: Vineet Gupta <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

1 files changed, 3 insertions, 0 deletions

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 245ac503f211..8d30cbda51b6 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2384,6 +2384,9 @@ 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:
+		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.");