tracing: Add function probe to trigger a ftrace dump of current CPU trace
authorSteven Rostedt (Red Hat) <rostedt@goodmis.org>
Tue, 30 Apr 2013 23:00:46 +0000 (19:00 -0400)
committerSteven Rostedt <rostedt@goodmis.org>
Tue, 11 Jun 2013 22:38:48 +0000 (18:38 -0400)
commit90e3c03c3a09a7b176b3fe59d78f5d9755ac8e37
treea37db37999a01fb1f425a19f5a9615faf1059b73
parentad71d889b88055e61e3970a6744a271a51a94f42
tracing: Add function probe to trigger a ftrace dump of current CPU trace

Add the "cpudump" command to have the current CPU ftrace buffer dumped
to console if a function is hit. This is useful when debugging a
tripple fault, where you have an idea of a function that is called
just before the tripple fault occurs, and can tell ftrace to dump its
content out to the console before it continues.

This differs from the "dump" command as it only dumps the content of
the ring buffer for the currently executing CPU, and does not show
the contents of the other CPUs.

Format is:

  <function>:cpudump

echo 'bad_address:cpudump' > /debug/tracing/set_ftrace_filter

To remove this:

echo '!bad_address:cpudump' > /debug/tracing/set_ftrace_filter

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Documentation/trace/ftrace.txt
kernel/trace/trace_functions.c