Merge commit 'v2.6.30-rc1' into core/urgent

Merge reason: need latest upstream to queue up dependent fix

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 17 insertions, 2 deletions

diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index d0871bc0aca5..c750f65f9661 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -245,16 +245,31 @@ static int trace_lookup_stack(struct seq_file *m, long i)
 #endif
 }
 
+static void print_disabled(struct seq_file *m)
+{
+        seq_puts(m, "#\n"
+                 "#  Stack tracer disabled\n"
+                 "#\n"
+                 "# To enable the stack tracer, either add 'stacktrace' to the\n"
+                 "# kernel command line\n"
+                 "# or 'echo 1 > /proc/sys/kernel/stack_tracer_enabled'\n"
+                 "#\n");
+}
+
 static int t_show(struct seq_file *m, void *v)
 {
         long i;
         int size;
 
         if (v == SEQ_START_TOKEN) {
-                seq_printf(m, "        Depth   Size      Location"
+                seq_printf(m, "        Depth    Size   Location"
                            "    (%d entries)\n"
-                           "        -----   ----      --------\n",
+                           "        -----    ----   --------\n",
                            max_stack_trace.nr_entries);
+
+                if (!stack_tracer_enabled && !max_stack_size)
+                        print_disabled(m);
+
                 return 0;
         }