| Message ID | 1594576158-75884-2-git-send-email-andrey.shinkevich@virtuozzo.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | scripts/simplebench: add bench_write_req.py test | expand |
12.07.2020 20:49, Andrey Shinkevich wrote: > 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) has the following results: > > SSD: > ----------------- ------------------- ------------------- > <qemu-img binary 1> <qemu-img binary 2> > <simple case> 0.34 +- 0.01 10.57 +- 0.96 > <general case> 0.33 +- 0.01 9.15 +- 0.85 > <cluster middle> 0.33 +- 0.00 8.72 +- 0.05 > <cluster overlap> 7.43 +- 1.19 14.35 +- 1.00 > ----------------- ------------------- ------------------- > HDD: > ----------------- ------------------- ------------------- > <qemu-img binary 1> <qemu-img binary 2> > <simple case> 32.61 +- 1.17 55.11 +- 1.15 > <general case> 54.28 +- 8.82 60.11 +- 2.76 > <cluster middle> 57.93 +- 0.47 58.53 +- 0.51 > <cluster overlap> 11.47 +- 0.94 17.29 +- 4.40 > ----------------- ------------------- ------------------- > > Suggested-by: Denis V. Lunev <den@openvz.org> > Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> > Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Andrey wants to drop 02,03 in v5, so this patch is a candidate for v5. Below my notes. > --- > scripts/simplebench/bench_write_req.py | 173 +++++++++++++++++++++++++++++++++ > 1 file changed, 173 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..a285ef1 > --- /dev/null > +++ b/scripts/simplebench/bench_write_req.py > @@ -0,0 +1,173 @@ > +#!/usr/bin/env python3 > +# > +# Test to compare performance of write requests for two qemu-img binary files. Let's note that patch is intended to check benefit of c8bb23cbdbe "qcow2: skip writing zero buffers to empty COW areas" > +# > +# 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']) > + > + > +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): > + """Benchmark write requests > + > + The function creates a QCOW2 image with the given path/name and fills it > + with random data optionally. No, it doesn't fill.. > + Then it runs the 'qemu-img bench' command and > + makes series of write requests on the image clusters. Finally, it returns > + the total time of the write operations on the disk. > + > + 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 > + > + 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(f'File not found: {qemu_img}') > + sys.exit(1) > + > + image_dir = os.path.dirname(os.path.abspath(image_name)) > + if not os.path.isdir(image_dir): > + print(f'Path not found: {image_name}') > + sys.exit(1) > + > + cluster_size = 1024 * 1024 > + image_size = 1024 * cluster_size > + seek = 4 > + dd_count = int(image_size / cluster_size) - seek seek and dd_count are unused > + > + args_create = [qemu_img, 'create', '-f', 'qcow2', '-o', > + f'cluster_size={cluster_size}', > + image_name, str(image_size)] > + > + count = requests * int(image_size / cluster_size) requests is number of requests per cluster.. > + step = str(cluster_size) but step is one cluster. So, we have several requests per cluster, but still, step is cluster? It sounds strange to me. Assume requests = 5 and we have image with 5 clusters. count would be 5 * 5 = 25. Trying to make 25 iterations with step=cluster will go far beyond the image size.. > + offset = str(block_offset) > + cnt = str(count) extra variables. Let's just use str() in args below. > + size = [] > + if block_size: > + size = ['-s', f'{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) 1. You may just write here if block_size: args_bench += ['-s', f'{block_size}'] No reason to create extra "size" variable to be used only here. 2. Why do you need this logic? If user pass block_size = 0, we instead rely on default bufsize of img_bench() which is 4096. And in two test-cases you use explicit 4096 constant, and in one you use 0 to be implicitly changed to same 4096. Let's instead specify block_size explicitly. > + > + try: > + qemu_img_pipe(*args_create) > + except OSError as e: > + os.remove(image_name) > + return {'error': 'qemu_img create failed: ' + str(e)} > + > + try: > + ret = qemu_img_pipe(*args_bench) > + finally: > + os.remove(image_name) > + if not ret: ret may be not defined, if exception shot prior to assignment of ret, isn't it? I suggest to not bother with "finally", and just make similar "except" like for previous case, and then just parse ret at function end. > + return {'error': 'qemu_img bench failed'} > + if 'seconds' in ret: > + ret_list = ret.split() > + index = ret_list.index('seconds.') > + return {'seconds': float(ret_list[index-1])} > + else: > + return {'error': 'qemu_img bench failed: ' + ret} > + > + > +if __name__ == '__main__': > + > + if len(sys.argv) < 4: > + program = os.path.basename(sys.argv[0]) > + print(f'USAGE: {program} <path to qemu-img binary file> ' > + '<path to another qemu-img to compare performance with> ' > + '<full or relative name for QCOW2 image to create>') > + 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 > + }, > + { > + 'id': '<general case>', > + 'block_size': 4096, > + 'block_offset': 0, > + 'requests': 10 > + }, Hmm I don't understand, why simple case and general case are different? As I already noted, if you don't specify -s for bench, as you do if block_size is 0, the default value is 4096 anyway in img_bench(). So, how there can be so different results in commit message? Or what am I missing? > + { > + 'id': '<cluster middle>', > + 'block_size': 4096, > + 'block_offset': 524288, > + 'requests': 10 > + }, > + { > + 'id': '<cluster overlap>', What is overlapping here? you just write half of cluster with a small offset from start of cluster. I'm OK with the case itself, I just don't understand the naming. > + 'block_size': 524288, > + 'block_offset': 4096, > + 'requests': 2 > + }, > + ] > + > + # 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': f'{sys.argv[1]}', > + 'image_name': f'{sys.argv[3]}' > + }, > + { > + 'id': '<qemu-img binary 2>', > + 'qemu_img': f'{sys.argv[2]}', > + 'image_name': f'{sys.argv[3]}' > + }, > + ] > + > + result = simplebench.bench(bench_func, test_envs, test_cases, count=3, > + initial_run=False) > + print(simplebench.ascii(result)) >
diff --git a/scripts/simplebench/bench_write_req.py b/scripts/simplebench/bench_write_req.py new file mode 100755 index 0000000..a285ef1 --- /dev/null +++ b/scripts/simplebench/bench_write_req.py @@ -0,0 +1,173 @@ +#!/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']) + + +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): + """Benchmark write requests + + The function creates a QCOW2 image with the given path/name and fills it + with random data optionally. Then it runs the 'qemu-img bench' command and + makes series of write requests on the image clusters. Finally, it returns + the total time of the write operations on the disk. + + 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 + + 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(f'File not found: {qemu_img}') + sys.exit(1) + + image_dir = os.path.dirname(os.path.abspath(image_name)) + if not os.path.isdir(image_dir): + print(f'Path not found: {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', + f'cluster_size={cluster_size}', + image_name, str(image_size)] + + count = requests * int(image_size / cluster_size) + step = str(cluster_size) + offset = str(block_offset) + cnt = str(count) + size = [] + if block_size: + size = ['-s', f'{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) + + try: + qemu_img_pipe(*args_create) + except OSError as e: + os.remove(image_name) + return {'error': 'qemu_img create failed: ' + str(e)} + + try: + ret = qemu_img_pipe(*args_bench) + finally: + os.remove(image_name) + if not ret: + return {'error': 'qemu_img bench failed'} + if 'seconds' in ret: + ret_list = ret.split() + index = ret_list.index('seconds.') + return {'seconds': float(ret_list[index-1])} + else: + return {'error': 'qemu_img bench failed: ' + ret} + + +if __name__ == '__main__': + + if len(sys.argv) < 4: + program = os.path.basename(sys.argv[0]) + print(f'USAGE: {program} <path to qemu-img binary file> ' + '<path to another qemu-img to compare performance with> ' + '<full or relative name for QCOW2 image to create>') + 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 + }, + { + 'id': '<general case>', + 'block_size': 4096, + 'block_offset': 0, + 'requests': 10 + }, + { + 'id': '<cluster middle>', + 'block_size': 4096, + 'block_offset': 524288, + 'requests': 10 + }, + { + 'id': '<cluster overlap>', + 'block_size': 524288, + 'block_offset': 4096, + 'requests': 2 + }, + ] + + # 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': f'{sys.argv[1]}', + 'image_name': f'{sys.argv[3]}' + }, + { + 'id': '<qemu-img binary 2>', + 'qemu_img': f'{sys.argv[2]}', + 'image_name': f'{sys.argv[3]}' + }, + ] + + result = simplebench.bench(bench_func, test_envs, test_cases, count=3, + initial_run=False) + print(simplebench.ascii(result))
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) has the following results: SSD: ----------------- ------------------- ------------------- <qemu-img binary 1> <qemu-img binary 2> <simple case> 0.34 +- 0.01 10.57 +- 0.96 <general case> 0.33 +- 0.01 9.15 +- 0.85 <cluster middle> 0.33 +- 0.00 8.72 +- 0.05 <cluster overlap> 7.43 +- 1.19 14.35 +- 1.00 ----------------- ------------------- ------------------- HDD: ----------------- ------------------- ------------------- <qemu-img binary 1> <qemu-img binary 2> <simple case> 32.61 +- 1.17 55.11 +- 1.15 <general case> 54.28 +- 8.82 60.11 +- 2.76 <cluster middle> 57.93 +- 0.47 58.53 +- 0.51 <cluster overlap> 11.47 +- 0.94 17.29 +- 4.40 ----------------- ------------------- ------------------- Suggested-by: Denis V. Lunev <den@openvz.org> Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> --- scripts/simplebench/bench_write_req.py | 173 +++++++++++++++++++++++++++++++++ 1 file changed, 173 insertions(+) create mode 100755 scripts/simplebench/bench_write_req.py