new file mode 100755
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+#!/usr/bin/env python3
+#
+# Benchmark preallocate filter
+#
+# 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 re
+
+import simplebench
+
+
+def qemu_img_bench(args):
+ p = subprocess.run(args, stdout=subprocess.PIPE, stderr=subprocess.STDOUT,
+ universal_newlines=True)
+
+ if p.returncode == 0:
+ try:
+ m = re.search(r'Run completed in (\d+.\d+) seconds.', p.stdout)
+ return {'seconds': float(m.group(1))}
+ except Exception:
+ return {'error': f'failed to parse qemu-img output: {p.stdout}'}
+ else:
+ return {'error': f'qemu-img failed: {p.returncode}: {p.stdout}'}
+
+
+def bench_func(env, case):
+ fname = f"{case['dir']}/prealloc-test.qcow2"
+ try:
+ os.remove(fname)
+ except OSError:
+ pass
+
+ subprocess.run([env['qemu-img-binary'], 'create', '-f', 'qcow2', fname,
+ '16G'], stdout=subprocess.DEVNULL,
+ stderr=subprocess.DEVNULL, check=True)
+
+ args = [env['qemu-img-binary'], 'bench', '-c', str(case['count']),
+ '-d', '64', '-s', case['block-size'], '-t', 'none', '-n', '-w']
+ if env['prealloc']:
+ args += ['--image-opts',
+ 'driver=qcow2,file.driver=preallocate,file.file.driver=file,'
+ f'file.file.filename={fname}']
+ else:
+ args += ['-f', 'qcow2', fname]
+
+ return qemu_img_bench(args)
+
+
+def auto_count_bench_func(env, case):
+ case['count'] = 100
+ while True:
+ res = bench_func(env, case)
+ if 'error' in res:
+ return res
+
+ if res['seconds'] >= 1:
+ break
+
+ case['count'] *= 10
+
+ if res['seconds'] < 5:
+ case['count'] = round(case['count'] * 5 / res['seconds'])
+ res = bench_func(env, case)
+ if 'error' in res:
+ return res
+
+ res['iops'] = case['count'] / res['seconds']
+ return res
+
+
+if __name__ == '__main__':
+ if len(sys.argv) < 2:
+ print(f'USAGE: {sys.argv[0]} <qemu-img binary> '
+ 'DISK_NAME:DIR_PATH ...')
+ exit(1)
+
+ qemu_img = sys.argv[1]
+
+ envs = [
+ {
+ 'id': 'no-prealloc',
+ 'qemu-img-binary': qemu_img,
+ 'prealloc': False
+ },
+ {
+ 'id': 'prealloc',
+ 'qemu-img-binary': qemu_img,
+ 'prealloc': True
+ }
+ ]
+
+ aligned_cases = []
+ unaligned_cases = []
+
+ for disk in sys.argv[2:]:
+ name, path = disk.split(':')
+ aligned_cases.append({
+ 'id': f'{name}, aligned sequential 16k',
+ 'block-size': '16k',
+ 'dir': path
+ })
+ unaligned_cases.append({
+ 'id': f'{name}, unaligned sequential 64k',
+ 'block-size': '16k',
+ 'dir': path
+ })
+
+ result = simplebench.bench(auto_count_bench_func, envs,
+ aligned_cases + unaligned_cases, count=5)
+ print(simplebench.ascii(result))
Benchmark for new preallocate filter. Example usage: ./bench_prealloc.py ../../build/qemu-img \ ssd-ext4:/path/to/mount/point \ ssd-xfs:/path2 hdd-ext4:/path3 hdd-xfs:/path4 The benchmark shows performance improvement (or degradation) when use new preallocate filter with qcow2 image. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> --- scripts/simplebench/bench_prealloc.py | 128 ++++++++++++++++++++++++++ 1 file changed, 128 insertions(+) create mode 100755 scripts/simplebench/bench_prealloc.py