From c286c419c784c238cd699be37fec7a9acc30d89f Mon Sep 17 00:00:00 2001
From: Arnaldo Carvalho de Melo <acme@redhat.com>
Date: Mon, 28 Mar 2011 09:50:11 -0300
Subject: perf tools: Fixup exit path when not able to open events
We have to deal with the TUI mode in perf top, so that we don't end up
with a garbled screen when, say, a non root user on a machine with a
paranoid setting (the default) tries to use 'perf top'.
Introduce a ui__warning_paranoid() routine shared by top and record that
tells the user the valid values for /proc/sys/kernel/perf_event_paranoid.
Cc: David Ahern <daahern@cisco.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/debug.c | 10 ++++++++++
1 file changed, 10 insertions(+)
(limited to 'tools/perf/util/debug.c')
diff --git a/tools/perf/util/debug.c b/tools/perf/util/debug.c
index d4536a9e0d8c..155749d74350 100644
--- a/tools/perf/util/debug.c
+++ b/tools/perf/util/debug.c
@@ -57,6 +57,16 @@ void ui__warning(const char *format, ...)
}
#endif
+void ui__warning_paranoid(void)
+{
+ ui__warning("Permission error - are you root?\n"
+ "Consider tweaking /proc/sys/kernel/perf_event_paranoid:\n"
+ " -1 - Not paranoid at all\n"
+ " 0 - Disallow raw tracepoint access for unpriv\n"
+ " 1 - Disallow cpu events for unpriv\n"
+ " 2 - Disallow kernel profiling for unpriv\n");
+}
+
void trace_event(union perf_event *event)
{
unsigned char *raw_event = (void *)event;
--
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