From cdce445906852d90efdc773ca7ba460e6e41664d Mon Sep 17 00:00:00 2001
From: Namhyung Kim <namhyung@gmail.com>
Date: Sun, 8 Jan 2012 02:25:27 +0900
Subject: [PATCH] perf top: Add error message for EMFILE
When a user tries to open so many events, perf_event_open syscall may
fail with EMFILE. Provide advise for that case.
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1325957132-10600-3-git-send-email-namhyung@gmail.com
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/builtin-top.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index d89dec90103e..8f80df896038 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -888,6 +888,10 @@ static void perf_top__start_counters(struct perf_top *top)
ui__warning("The %s event is not supported.\n",
event_name(counter));
goto out_err;
+ } else if (err == EMFILE) {
+ ui__warning("Too many events are opened.\n"
+ "Try again after reducing the number of events\n");
+ goto out_err;
}
ui__warning("The sys_perf_event_open() syscall "
--
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