perf tools: Add hint for 'Too many events are opened.' error message
Enhancing the 'Too many events are opened.' error message with hint to
use use 'ulimit -n <limit>' command.
Before:
$ perf record -e 'sched:*,syscalls:*' ls
Error:
Too many events are opened.
Try again after reducing the number of events.
Now:
$ perf record -e 'sched:*,syscalls:*' ls
Error:
Too many events are opened.
Probably the maximum number of open file descriptors has been reached.
Hint: Try again after reducing the number of events.
Hint: Try increasing the limit with 'ulimit -n <limit>'
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1432587114-14924-1-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index c886b9f..a3e36fc 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2149,7 +2149,9 @@
case EMFILE:
return scnprintf(msg, size, "%s",
"Too many events are opened.\n"
- "Try again after reducing the number of events.");
+ "Probably the maximum number of open file descriptors has been reached.\n"
+ "Hint: Try again after reducing the number of events.\n"
+ "Hint: Try increasing the limit with 'ulimit -n <limit>'");
case ENODEV:
if (target->cpu_list)
return scnprintf(msg, size, "%s",
