
When doing Python programming it is a nice convention to insert the if statement `if __name__ == "__main__":` before any main code that does actual functionalities to ensure the code will be executed only as a script rather than as an imported module. Hence attach the missing judgement to show_delta. Link: https://lkml.kernel.org/r/20231013132832.165768-1-2023002089@link.tyut.edu.cn Signed-off-by: Hu Haowen <2023002089@link.tyut.edu.cn> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Miguel Ojeda <ojeda@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Nicolas Schier <n.schier@avm.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
3.0 KiB
Executable File
#!/usr/bin/env python
SPDX-License-Identifier: GPL-2.0-only
show_deltas: Read list of printk messages instrumented with
time data, and format with time deltas.
Also, you can show the times relative to a fixed point.
Copyright 2003 Sony Corporation
import sys import string
def usage(): print ("""usage: show_delta []
This program parses the output from a set of printk message lines which have time data prefixed because the CONFIG_PRINTK_TIME option is set, or the kernel command line option "time" is specified. When run with no options, the time information is converted to show the time delta between each printk line and the next. When run with the '-b' option, all times are relative to a single (base) point in time.
Options: -h Show this usage help. -b Specify a base for time references. can be a number or a string. If it is a string, the first message line which matches (at the beginning of the line) is used as the time reference.
ex: $ dmesg >timefile $ show_delta -b NET4 timefile
will show times relative to the line in the kernel output starting with "NET4". """) sys.exit(1)
returns a tuple containing the seconds and text for each message line
seconds is returned as a float
raise an exception if no timing data was found
def get_time(line): if line[0]!="[": raise ValueError
# split on closing bracket
(time_str, rest) = string.split(line[1:],']',1)
time = string.atof(time_str)
#print "time=", time
return (time, rest)
average line looks like:
[ 0.084282] VFS: Mounted root (romfs filesystem) readonly
time data is expressed in seconds.useconds,
convert_line adds a delta for each line
last_time = 0.0 def convert_line(line, base_time): global last_time
try:
(time, rest) = get_time(line)
except:
# if any problem parsing time, don't convert anything
return line
if base_time:
# show time from base
delta = time - base_time
else:
# just show time from last line
delta = time - last_time
last_time = time
return ("[%5.6f < %5.6f >]" % (time, delta)) + rest
def main(): base_str = "" filein = "" for arg in sys.argv[1:]: if arg=="-b": base_str = sys.argv[sys.argv.index("-b")+1] elif arg=="-h": usage() else: filein = arg
if not filein:
usage()
try:
lines = open(filein,"r").readlines()
except:
print ("Problem opening file: %s" % filein)
sys.exit(1)
if base_str:
print ('base= "%s"' % base_str)
# assume a numeric base. If that fails, try searching
# for a matching line.
try:
base_time = float(base_str)
except:
# search for line matching <base> string
found = 0
for line in lines:
try:
(time, rest) = get_time(line)
except:
continue
if string.find(rest, base_str)==1:
base_time = time
found = 1
# stop at first match
break
if not found:
print ('Couldn\'t find line matching base pattern "%s"' % base_str)
sys.exit(1)
else:
base_time = 0.0
for line in lines:
print (convert_line(line, base_time),)
if name == "main": main()