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author | Frederic Weisbecker <fweisbec@gmail.com> | 2008-10-27 02:05:25 +0100 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-10-27 11:00:07 +0100 |
commit | f4a2a0d9a4226846693b5b4462d4350c1bfd58ea (patch) | |
tree | dc9ba5a5f9ef32cbcd720123ec4d5124e133acbf | |
parent | f8d56f1771e4867acc461146764b4feeb5245669 (diff) | |
download | linux-f4a2a0d9a4226846693b5b4462d4350c1bfd58ea.tar.bz2 |
ftrace: add a script to produce a hierarchical view of a function trace
This script parses a function trace and then produces a hierarchical
view of the function call stack after processing it into a tree.
Changes on V2 thanks to the trace sent by Steven:
- Support both the files "trace" and "trace_pipe" (comments and space
differences)
- Correct the mini HOW-TO at the beginning.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r-- | scripts/tracing/draw_functrace.py | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/scripts/tracing/draw_functrace.py b/scripts/tracing/draw_functrace.py new file mode 100644 index 000000000000..902f9a992620 --- /dev/null +++ b/scripts/tracing/draw_functrace.py @@ -0,0 +1,130 @@ +#!/usr/bin/python + +""" +Copyright 2008 (c) Frederic Weisbecker <fweisbec@gmail.com> +Licensed under the terms of the GNU GPL License version 2 + +This script parses a trace provided by the function tracer in +kernel/trace/trace_functions.c +The resulted trace is processed into a tree to produce a more human +view of the call stack by drawing textual but hierarchical tree of +calls. Only the functions's names and the the call time are provided. + +Usage: + Be sure that you have CONFIG_FUNCTION_TRACER + # mkdir /debugfs + # mount -t debug debug /debug + # echo function > /debug/tracing/current_tracer + $ cat /debug/tracing/trace_pipe > ~/raw_trace_func + Wait some times but not too much, the script is a bit slow. + Break the pipe (Ctrl + Z) + $ scripts/draw_functrace.py < raw_trace_func > draw_functrace + Then you have your drawn trace in draw_functrace +""" + + +import sys, re + +class CallTree: + """ This class provides a tree representation of the functions + call stack. If a function has no parent in the kernel (interrupt, + syscall, kernel thread...) then it is attached to a virtual parent + called ROOT. + """ + ROOT = None + + def __init__(self, func, time = None, parent = None): + self._func = func + self._time = time + if parent is None: + self._parent = CallTree.ROOT + else: + self._parent = parent + self._children = [] + + def calls(self, func, calltime): + """ If a function calls another one, call this method to insert it + into the tree at the appropriate place. + @return: A reference to the newly created child node. + """ + child = CallTree(func, calltime, self) + self._children.append(child) + return child + + def getParent(self, func): + """ Retrieve the last parent of the current node that + has the name given by func. If this function is not + on a parent, then create it as new child of root + @return: A reference to the parent. + """ + tree = self + while tree != CallTree.ROOT and tree._func != func: + tree = tree._parent + if tree == CallTree.ROOT: + child = CallTree.ROOT.calls(func, None) + return child + return tree + + def __repr__(self): + return self.__toString("", True) + + def __toString(self, branch, lastChild): + if self._time is not None: + s = "%s----%s (%s)\n" % (branch, self._func, self._time) + else: + s = "%s----%s\n" % (branch, self._func) + + i = 0 + if lastChild: + branch = branch[:-1] + " " + while i < len(self._children): + if i != len(self._children) - 1: + s += "%s" % self._children[i].__toString(branch +\ + " |", False) + else: + s += "%s" % self._children[i].__toString(branch +\ + " |", True) + i += 1 + return s + +class BrokenLineException(Exception): + """If the last line is not complete because of the pipe breakage, + we want to stop the processing and ignore this line. + """ + pass + +class CommentLineException(Exception): + """ If the line is a comment (as in the beginning of the trace file), + just ignore it. + """ + pass + + +def parseLine(line): + line = line.strip() + if line.startswith("#"): + raise CommentLineException + m = re.match("[^]]+?\\] +([0-9.]+): (\\w+) <-(\\w+)", line) + if m is None: + raise BrokenLineException + return (m.group(1), m.group(2), m.group(3)) + + +def main(): + CallTree.ROOT = CallTree("Root (Nowhere)", None, None) + tree = CallTree.ROOT + + for line in sys.stdin: + try: + calltime, callee, caller = parseLine(line) + except BrokenLineException: + break + except CommentLineException: + continue + tree = tree.getParent(caller) + tree = tree.calls(callee, calltime) + + print CallTree.ROOT + +if __name__ == "__main__": + main() |