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

From: Namhyung Kim
Date: Sun Jan 08 2012 - 10:56:00 EST


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@xxxxxxxxx>
---
tools/perf/builtin-stat.c | 3 +++
1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index f5d2a63eba66..3e6c8dd8417f 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -477,6 +477,9 @@ static int run_perf_stat(int argc __used, const char **argv)
"\t Consider tweaking"
" /proc/sys/kernel/perf_event_paranoid or running as root.",
system_wide ? "system-wide " : "");
+ } else if (errno == EMFILE) {
+ error("Too many events are opened.\n"
+ "\t Try again after reducing the number of events.\n");
} else {
error("open_counter returned with %d (%s). "
"/bin/dmesg may provide additional information.\n",
--
1.7.8.2

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