From: Namhyung Kim <namhyung@gmail.com>
Date: Sat, 7 Jan 2012 17:25:27 +0000 (+0900)
Subject: perf top: Add error message for EMFILE
X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=cdce445906852d90efdc773ca7ba460e6e41664d;p=~shefty%2Frdma-dev.git

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>
---

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index d89dec90103..8f80df89603 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -888,6 +888,10 @@ try_again:
 				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 "