glibc/benchtests/scripts/compare_bench.py

185 lines
6.6 KiB
Python
Executable File

#!/usr/bin/python
# Copyright (C) 2015-2016 Free Software Foundation, Inc.
# This file is part of the GNU C Library.
#
# The GNU C Library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# The GNU C Library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with the GNU C Library; if not, see
# <http://www.gnu.org/licenses/>.
"""Compare two benchmark results
Given two benchmark result files and a threshold, this script compares the
benchmark results and flags differences in performance beyond a given
threshold.
"""
import sys
import os
import pylab
import import_bench as bench
def do_compare(func, var, tl1, tl2, par, threshold):
"""Compare one of the aggregate measurements
Helper function to compare one of the aggregate measurements of a function
variant.
Args:
func: Function name
var: Function variant name
tl1: The first timings list
tl2: The second timings list
par: The aggregate to measure
threshold: The threshold for differences, beyond which the script should
print a warning.
"""
d = abs(tl2[par] - tl1[par]) * 100 / tl1[str(par)]
if d > threshold:
if tl1[par] > tl2[par]:
ind = '+++'
else:
ind = '---'
print('%s %s(%s)[%s]: (%.2lf%%) from %g to %g' %
(ind, func, var, par, d, tl1[par], tl2[par]))
def compare_runs(pts1, pts2, threshold):
"""Compare two benchmark runs
Args:
pts1: Timing data from first machine
pts2: Timing data from second machine
"""
# XXX We assume that the two benchmarks have identical functions and
# variants. We cannot compare two benchmarks that may have different
# functions or variants. Maybe that is something for the future.
for func in pts1['functions'].keys():
for var in pts1['functions'][func].keys():
tl1 = pts1['functions'][func][var]
tl2 = pts2['functions'][func][var]
# Compare the consolidated numbers
# do_compare(func, var, tl1, tl2, 'max', threshold)
do_compare(func, var, tl1, tl2, 'min', threshold)
do_compare(func, var, tl1, tl2, 'mean', threshold)
# Skip over to the next variant or function if there is no detailed
# timing info for the function variant.
if 'timings' not in pts1['functions'][func][var].keys() or \
'timings' not in pts2['functions'][func][var].keys():
return
# If two lists do not have the same length then it is likely that
# the performance characteristics of the function have changed.
# XXX: It is also likely that there was some measurement that
# strayed outside the usual range. Such ouiers should not
# happen on an idle machine with identical hardware and
# configuration, but ideal environments are hard to come by.
if len(tl1['timings']) != len(tl2['timings']):
print('* %s(%s): Timing characteristics changed' %
(func, var))
print('\tBefore: [%s]' %
', '.join([str(x) for x in tl1['timings']]))
print('\tAfter: [%s]' %
', '.join([str(x) for x in tl2['timings']]))
continue
# Collect numbers whose differences cross the threshold we have
# set.
issues = [(x, y) for x, y in zip(tl1['timings'], tl2['timings']) \
if abs(y - x) * 100 / x > threshold]
# Now print them.
for t1, t2 in issues:
d = abs(t2 - t1) * 100 / t1
if t2 > t1:
ind = '-'
else:
ind = '+'
print("%s %s(%s): (%.2lf%%) from %g to %g" %
(ind, func, var, d, t1, t2))
def plot_graphs(bench1, bench2):
"""Plot graphs for functions
Make scatter plots for the functions and their variants.
Args:
bench1: Set of points from the first machine
bench2: Set of points from the second machine.
"""
for func in bench1['functions'].keys():
for var in bench1['functions'][func].keys():
# No point trying to print a graph if there are no detailed
# timings.
if u'timings' not in bench1['functions'][func][var].keys():
print('Skipping graph for %s(%s)' % (func, var))
continue
pylab.clf()
pylab.ylabel('Time (cycles)')
# First set of points
length = len(bench1['functions'][func][var]['timings'])
X = [float(x) for x in range(length)]
lines = pylab.scatter(X, bench1['functions'][func][var]['timings'],
1.5 + 100 / length)
pylab.setp(lines, 'color', 'r')
# Second set of points
length = len(bench2['functions'][func][var]['timings'])
X = [float(x) for x in range(length)]
lines = pylab.scatter(X, bench2['functions'][func][var]['timings'],
1.5 + 100 / length)
pylab.setp(lines, 'color', 'g')
if var:
filename = "%s-%s.png" % (func, var)
else:
filename = "%s.png" % func
print('Writing out %s' % filename)
pylab.savefig(filename)
def main(args):
"""Program Entry Point
Take two benchmark output files and compare their timings.
"""
if len(args) > 4 or len(args) < 3:
print('Usage: %s <schema> <file1> <file2> [threshold in %%]' % sys.argv[0])
sys.exit(os.EX_USAGE)
bench1 = bench.parse_bench(args[1], args[0])
bench2 = bench.parse_bench(args[2], args[0])
if len(args) == 4:
threshold = float(args[3])
else:
threshold = 10.0
if (bench1['timing_type'] != bench2['timing_type']):
print('Cannot compare benchmark outputs: timing types are different')
return
plot_graphs(bench1, bench2)
bench.compress_timings(bench1)
bench.compress_timings(bench2)
compare_runs(bench1, bench2, threshold)
if __name__ == '__main__':
main(sys.argv[1:])