From 90e3c03c3a09a7b176b3fe59d78f5d9755ac8e37 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Tue, 30 Apr 2013 19:00:46 -0400 Subject: 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: :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 --- Documentation/trace/ftrace.txt | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'Documentation/trace') diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt index cc9ec57e157..b937c6e2163 100644 --- a/Documentation/trace/ftrace.txt +++ b/Documentation/trace/ftrace.txt @@ -2437,6 +2437,12 @@ The following commands are supported: is hit. Perhaps its a function that is called before a tripple fault happens and does not allow you to get a regular dump. +- cpudump + When the function is hit, it will dump the contents of the ftrace + ring buffer for the current CPU to the console. Unlike the "dump" + command, it only prints out the contents of the ring buffer for the + CPU that executed the function that triggered the dump. + trace_pipe ---------- -- cgit v1.2.3-70-g09d2