[PATCH 2/2] perf record: Mention paranoid sysctl when failing to create counter
From: Arnaldo Carvalho de Melo
Date: Thu Mar 11 2010 - 13:53:37 EST
From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
[acme@mica linux-2.6-tip]$ perf record -a -f
Fatal: Permission error - are you root?
Consider tweaking /proc/sys/kernel/perf_event_paranoid.
[acme@mica linux-2.6-tip]$
Suggested-by: Ingo Molnar <mingo@xxxxxxx>
Cc: FrÃdÃric Weisbecker <fweisbec@xxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/builtin-record.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 3bf1409..b280ab5 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -283,7 +283,8 @@ try_again:
int err = errno;
if (err == EPERM || err == EACCES)
- die("Permission error - are you root?\n");
+ die("Permission error - are you root?\n"
+ "\t Consider tweaking /proc/sys/kernel/perf_event_paranoid.\n");
else if (err == ENODEV && profile_cpu != -1)
die("No such device - did you specify an out-of-range profile CPU?\n");
--
1.5.5.1
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