Root/scripts/show_delta

Source at commit cdde9cf73945d547acd3e96f9508c79e84ad0bf1 created 9 years 4 months ago.
By Maarten ter Huurne, MMC: JZ4740: Added support for CPU frequency changing
1#!/usr/bin/python
2#
3# show_deltas: Read list of printk messages instrumented with
4# time data, and format with time deltas.
5#
6# Also, you can show the times relative to a fixed point.
7#
8# Copyright 2003 Sony Corporation
9#
10# GPL 2.0 applies.
11
12import sys
13import string
14
15def usage():
16    print """usage: show_delta [<options>] <filename>
17
18This program parses the output from a set of printk message lines which
19have time data prefixed because the CONFIG_PRINTK_TIME option is set, or
20the kernel command line option "time" is specified. When run with no
21options, the time information is converted to show the time delta between
22each printk line and the next. When run with the '-b' option, all times
23are relative to a single (base) point in time.
24
25Options:
26  -h Show this usage help.
27  -b <base> Specify a base for time references.
28        <base> can be a number or a string.
29        If it is a string, the first message line
30        which matches (at the beginning of the
31        line) is used as the time reference.
32
33ex: $ dmesg >timefile
34    $ show_delta -b NET4 timefile
35
36will show times relative to the line in the kernel output
37starting with "NET4".
38"""
39    sys.exit(1)
40
41# returns a tuple containing the seconds and text for each message line
42# seconds is returned as a float
43# raise an exception if no timing data was found
44def get_time(line):
45    if line[0]!="[":
46        raise ValueError
47
48    # split on closing bracket
49    (time_str, rest) = string.split(line[1:],']',1)
50    time = string.atof(time_str)
51
52    #print "time=", time
53    return (time, rest)
54
55
56# average line looks like:
57# [ 0.084282] VFS: Mounted root (romfs filesystem) readonly
58# time data is expressed in seconds.useconds,
59# convert_line adds a delta for each line
60last_time = 0.0
61def convert_line(line, base_time):
62    global last_time
63
64    try:
65        (time, rest) = get_time(line)
66    except:
67        # if any problem parsing time, don't convert anything
68        return line
69
70    if base_time:
71        # show time from base
72        delta = time - base_time
73    else:
74        # just show time from last line
75        delta = time - last_time
76        last_time = time
77
78    return ("[%5.6f < %5.6f >]" % (time, delta)) + rest
79
80def main():
81    base_str = ""
82    filein = ""
83    for arg in sys.argv[1:]:
84        if arg=="-b":
85            base_str = sys.argv[sys.argv.index("-b")+1]
86        elif arg=="-h":
87            usage()
88        else:
89            filein = arg
90
91    if not filein:
92        usage()
93
94    try:
95        lines = open(filein,"r").readlines()
96    except:
97        print "Problem opening file: %s" % filein
98        sys.exit(1)
99
100    if base_str:
101        print 'base= "%s"' % base_str
102        # assume a numeric base. If that fails, try searching
103        # for a matching line.
104        try:
105            base_time = float(base_str)
106        except:
107            # search for line matching <base> string
108            found = 0
109            for line in lines:
110                try:
111                    (time, rest) = get_time(line)
112                except:
113                    continue
114                if string.find(rest, base_str)==1:
115                    base_time = time
116                    found = 1
117                    # stop at first match
118                    break
119            if not found:
120                print 'Couldn\'t find line matching base pattern "%s"' % base_str
121                sys.exit(1)
122    else:
123        base_time = 0.0
124
125    for line in lines:
126        print convert_line(line, base_time),
127
128main()
129
130

Archive Download this file



interactive