[PATCH 2/3] perf record: Add error message for EMFILE

[Namhyung Kim <namhyung@gmail.com>]

When a user tries to open so many events, perf_event_oen syscall
may fail with EMFILE. Provide an advice for that case.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
---
 tools/perf/builtin-record.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 0abfb18b911f..d47b8277ca78 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -248,6 +248,10 @@ try_again:
 				ui__warning("The %s event is not supported.\n",
 					    event_name(pos));
 				exit(EXIT_FAILURE);
+			} else if (err == EMFILE) {
+				ui__warning("Too many events are opened.\n"
+					    "Try again after reducing the number of events.\n");
+				exit(EXIT_FAILURE);
 			}
 
 			printf("\n");
-- 
1.7.8.2