The script 'bench_write_req.py' allows comparing performances of write request for two qemu-img binary files. An example with (qemu-img binary 1) and without (qemu-img binary 2) the applied patch "qcow2: skip writing zero buffers to empty COW areas" (git commit ID: c8bb23cbdbe32f5) The <unaligned> case does not involve the COW optimization.
SSD: ----------------- ------------------- ------------------- <qemu-img binary 1> <qemu-img binary 2> <simple case> 2.72 +- 0.00 11.67 +- 1.04 <general case> 0.34 +- 0.00 8.64 +- 1.55 <cluster middle> 0.33 +- 0.01 8.13 +- 2.05 <cluster overlap> 8.46 +- 0.06 12.97 +- 1.07 <unaligned> 9.27 +- 2.04 8.83 +- 0.84 ----------------- ------------------- ------------------- HDD: ----------------- ------------------- ------------------- <qemu-img binary 1> <qemu-img binary 2> <simple case> 617.86 +- 6.78 608.84 +- 10.72 <general case> 57.53 +- 3.56 52.99 +- 7.48 <cluster middle> 60.50 +- 1.92 56.11 +- 5.20 <cluster overlap> 12.10 +- 1.10 15.16 +- 2.56 <unaligned> 6.23 +- 0.05 6.40 +- 0.07 ----------------- ------------------- ------------------- Suggested-by: Denis V. Lunev <d...@openvz.org> Suggested-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> Signed-off-by: Andrey Shinkevich <andrey.shinkev...@virtuozzo.com> --- v2: 01: Three more test cases added to the script: <simple case> <general case> <unaligned> scripts/simplebench/bench_write_req.py | 201 +++++++++++++++++++++++++++++++++ 1 file changed, 201 insertions(+) create mode 100755 scripts/simplebench/bench_write_req.py diff --git a/scripts/simplebench/bench_write_req.py b/scripts/simplebench/bench_write_req.py new file mode 100755 index 0000000..fe92d01 --- /dev/null +++ b/scripts/simplebench/bench_write_req.py @@ -0,0 +1,201 @@ +#!/usr/bin/env python3 +# +# Test to compare performance of write requests for two qemu-img binary files. +# +# Copyright (c) 2020 Virtuozzo International GmbH. +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 2 of the License, or +# (at your option) any later version. +# +# This program 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 General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see <http://www.gnu.org/licenses/>. +# + + +import sys +import os +import subprocess +import simplebench + + +def bench_func(env, case): + """ Handle one "cell" of benchmarking table. """ + return bench_write_req(env['qemu_img'], env['image_name'], + case['block_size'], case['block_offset'], + case['requests'], case['empty_image']) + + +def qemu_img_pipe(*args): + '''Run qemu-img and return its output''' + subp = subprocess.Popen(list(args), + stdout=subprocess.PIPE, + stderr=subprocess.STDOUT, + universal_newlines=True) + exitcode = subp.wait() + if exitcode < 0: + sys.stderr.write('qemu-img received signal %i: %s\n' + % (-exitcode, ' '.join(list(args)))) + return subp.communicate()[0] + + +def bench_write_req(qemu_img, image_name, block_size, block_offset, requests, + empty_image): + """Benchmark write requests + + qemu_img -- path to qemu_img executable file + image_name -- QCOW2 image name to create + block_size -- size of a block to write to clusters + block_offset -- offset of the block in clusters + requests -- number of write requests per cluster, customize if zero + empty_image -- if True, fill image with random data + + Returns {'seconds': int} on success and {'error': str} on failure. + Return value is compatible with simplebench lib. + """ + + if not os.path.isfile(qemu_img): + print('File not found: {}'.format(qemu_img)) + sys.exit(1) + + image_dir = os.path.dirname(os.path.abspath(image_name)) + if not os.path.isdir(image_dir): + print('Path not found: {}'.format(image_name)) + sys.exit(1) + + cluster_size = 1024 * 1024 + image_size = 1024 * cluster_size + seek = 4 + dd_count = int(image_size / cluster_size) - seek + + args_create = [qemu_img, 'create', '-f', 'qcow2', '-o', + 'cluster_size={}'.format(cluster_size), + image_name, str(image_size)] + + if requests: + count = requests * int(image_size / cluster_size) + step = str(cluster_size) + else: + # Create unaligned write requests + assert block_size + shift = int(block_size * 1.01) + count = int((image_size - block_offset) / shift) + step = str(shift) + depth = ['-d', '2'] + + offset = str(block_offset) + cnt = str(count) + size = [] + if block_size: + size = ['-s', '{}'.format(block_size)] + + args_bench = [qemu_img, 'bench', '-w', '-n', '-t', 'none', '-c', cnt, + '-S', step, '-o', offset, '-f', 'qcow2', image_name] + if block_size: + args_bench.extend(size) + if not requests: + args_bench.extend(depth) + + try: + qemu_img_pipe(*args_create) + + if not empty_image: + dd = ['dd', 'if=/dev/urandom', 'of={}'.format(image_name), + 'bs={}'.format(cluster_size), 'seek={}'.format(seek), + 'count={}'.format(dd_count), '&&', 'sync'] + devnull = open('/dev/null', 'w') + subprocess.call(dd, stderr=devnull, stdout=devnull) + + except OSError as e: + return {'error': 'qemu_img create failed: ' + str(e)} + + try: + ret = qemu_img_pipe(*args_bench) + except OSError as e: + return {'error': 'qemu_img bench failed: ' + str(e)} + finally: + os.remove(image_name) + if not ret: + return {'error': 'qemu_img bench failed'} + if 'seconds' in ret: + ret = ret.split() + index = ret.index('seconds.') + return {'seconds': float(ret[index-1])} + else: + return {'error': 'qemu_img bench failed: ' + ret} + + +if __name__ == '__main__': + + if len(sys.argv) < 4: + print('USAGE: {} <path to qemu-img binary file> ' + '<path to another qemu-img to compare performance with> ' + '<full or relative name for QCOW2 image to create>' + ''.format(os.path.basename(sys.argv[0]))) + exit(1) + + # Test-cases are "rows" in benchmark resulting table, 'id' is a caption + # for the row, other fields are handled by bench_func. + test_cases = [ + { + 'id': '<simple case>', + 'block_size': 0, + 'block_offset': 0, + 'requests': 10, + 'empty_image': False + }, + { + 'id': '<general case>', + 'block_size': 4096, + 'block_offset': 0, + 'requests': 10, + 'empty_image': False + }, + { + 'id': '<cluster middle>', + 'block_size': 4096, + 'block_offset': 524288, + 'requests': 10, + 'empty_image': False + }, + { + 'id': '<cluster overlap>', + 'block_size': 524288, + 'block_offset': 4096, + 'requests': 2, + 'empty_image': False + }, + { + 'id': '<unaligned>', + 'block_size': 104857600, + 'block_offset': 524288, + 'requests': 0, + 'empty_image': False + }, + ] + + # Test-envs are "columns" in benchmark resulting table, 'id is a caption + # for the column, other fields are handled by bench_func. + # Set the paths below to desired values + test_envs = [ + { + 'id': '<qemu-img binary 1>', + 'qemu_img': '{}'.format(sys.argv[1]), + 'image_name': '{}'.format(sys.argv[3]) + }, + { + 'id': '<qemu-img binary 2>', + 'qemu_img': '{}'.format(sys.argv[2]), + 'image_name': '{}'.format(sys.argv[3]) + }, + ] + + result = simplebench.bench(bench_func, test_envs, test_cases, count=3, + initial_run=False) + print(simplebench.ascii(result)) -- 1.8.3.1