tools/cgroup/iocost_coef_gen.py

8 Generate linear IO cost model coefficients used by the blk-iocost
11 ./iocost-coef-fio.testfile.  The result can be written directly to
14 On high performance devices, --numjobs > 1 is needed to achieve
17 See Documentation/admin-guide/cgroup-v2.rst and block/blk-iocost.c
34 parser.add_argument('--testdev', metavar='DEV',
35                     help='Raw block device to use for testing, ignores --testfile-size')
36 parser.add_argument('--testfile-size-gb', type=float, metavar='GIGABYTES', default=16,
38 parser.add_argument('--duration', type=int, metavar='SECONDS', default=120,
40 parser.add_argument('--seqio-block-mb', metavar='MEGABYTES', type=int, default=128,
42 parser.add_argument('--seq-depth', type=int, metavar='DEPTH', default=64,
44 parser.add_argument('--rand-depth', type=int, metavar='DEPTH', default=64,
46 parser.add_argument('--numjobs', type=int, metavar='JOBS', default=1,
48 parser.add_argument('--quiet', action='store_true')
49 parser.add_argument('--verbose', action='store_true')
59 # determine ('DEVNAME', 'MAJ:MIN') for @path
60 def dir_to_dev(path):  argument
62     devname = subprocess.run(f'findmnt -nvo SOURCE -T{path}',
63                              stdout=subprocess.PIPE, shell=True).stdout
64     devname = os.path.basename(devname).decode('utf-8').strip()
66     # partition -> whole device
69         devname = os.path.basename(os.path.dirname(parents[0]))
73 def create_testfile(path, size):  argument
76     if os.path.isfile(path) and os.stat(path).st_size == size:
79     info(f'Creating testfile {path}')
80     subprocess.check_call(f'rm -f {path}', shell=True)
81     subprocess.check_call(f'touch {path}', shell=True)
82     subprocess.call(f'chattr +C {path}', shell=True)
84         f'pv -s {size} -pr /dev/urandom {"-q" if args.quiet else ""} | '
85         f'dd of={path} count={size} '
94     cmd = (f'fio --direct=1 --ioengine=libaio --name=coef '
95            f'--filename={testfile} --runtime={round(duration)} '
96            f'--readwrite={iotype} --iodepth={iodepth} --blocksize={blocksize} '
97            f'--eta={eta} --output-format json --output={outfile.name} '
98            f'--time_based --numjobs={jobs}')
127     devname = os.path.basename(args.testdev)
134     testfile = 'iocost-coef-fio.testfile'