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authorSteven Rostedt (Red Hat) <rostedt@goodmis.org>2013-04-30 19:00:46 -0400
committerSteven Rostedt <rostedt@goodmis.org>2013-06-11 18:38:48 -0400
commit90e3c03c3a09a7b176b3fe59d78f5d9755ac8e37 (patch)
treea37db37999a01fb1f425a19f5a9615faf1059b73 /Documentation/trace
parentad71d889b88055e61e3970a6744a271a51a94f42 (diff)
downloadop-kernel-dev-90e3c03c3a09a7b176b3fe59d78f5d9755ac8e37.zip
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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>
Diffstat (limited to 'Documentation/trace')
-rw-r--r--Documentation/trace/ftrace.txt6
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt
index cc9ec57..b937c6e 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
----------
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