ftrace: ftrace_dump_on_oops=[tracer]

Impact: add new (optional) debug boot option

In order to facilitate early boot trouble, allow one to specify a tracer
on the kernel boot line.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 8 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 1bbcaa8982b6..4862284d3119 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -765,6 +765,14 @@ and is between 256 and 4096 characters. It is defined in the file
                         parameter will force ia64_sal_cache_flush to call
                         ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.
 
+        ftrace=[tracer]
+                        [ftrace] will set and start the specified tracer
+                        as early as possible in order to facilitate early
+                        boot debugging.
+
+        ftrace_dump_on_oops
+                        [ftrace] will dump the trace buffers on oops.
+
         gamecon.map[2|3]=
                         [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
                         support via parallel port (up to 5 devices per port)