xref: /linux/tools/mm/thpmaps (revision 906fd46a65383cd639e5eec72a047efc33045d86)
1#!/usr/bin/env python3
2# SPDX-License-Identifier: GPL-2.0-only
3# Copyright (C) 2024 ARM Ltd.
4#
5# Utility providing smaps-like output detailing transparent hugepage usage.
6# For more info, run:
7# ./thpmaps --help
8#
9# Requires numpy:
10# pip3 install numpy
11
12
13import argparse
14import collections
15import math
16import os
17import re
18import resource
19import shutil
20import sys
21import textwrap
22import time
23import numpy as np
24
25
26with open('/sys/kernel/mm/transparent_hugepage/hpage_pmd_size') as f:
27    PAGE_SIZE = resource.getpagesize()
28    PAGE_SHIFT = int(math.log2(PAGE_SIZE))
29    PMD_SIZE = int(f.read())
30    PMD_ORDER = int(math.log2(PMD_SIZE / PAGE_SIZE))
31
32
33def align_forward(v, a):
34    return (v + (a - 1)) & ~(a - 1)
35
36
37def align_offset(v, a):
38    return v & (a - 1)
39
40
41def kbnr(kb):
42    # Convert KB to number of pages.
43    return (kb << 10) >> PAGE_SHIFT
44
45
46def nrkb(nr):
47    # Convert number of pages to KB.
48    return (nr << PAGE_SHIFT) >> 10
49
50
51def odkb(order):
52    # Convert page order to KB.
53    return (PAGE_SIZE << order) >> 10
54
55
56def cont_ranges_all(search, index):
57    # Given a list of arrays, find the ranges for which values are monotonically
58    # incrementing in all arrays. all arrays in search and index must be the
59    # same size.
60    sz = len(search[0])
61    r = np.full(sz, 2)
62    d = np.diff(search[0]) == 1
63    for dd in [np.diff(arr) == 1 for arr in search[1:]]:
64        d &= dd
65    r[1:] -= d
66    r[:-1] -= d
67    return [np.repeat(arr, r).reshape(-1, 2) for arr in index]
68
69
70class ArgException(Exception):
71    pass
72
73
74class FileIOException(Exception):
75    pass
76
77
78class BinArrayFile:
79    # Base class used to read /proc/<pid>/pagemap and /proc/kpageflags into a
80    # numpy array. Use inherrited class in a with clause to ensure file is
81    # closed when it goes out of scope.
82    def __init__(self, filename, element_size):
83        self.element_size = element_size
84        self.filename = filename
85        self.fd = os.open(self.filename, os.O_RDONLY)
86
87    def cleanup(self):
88        os.close(self.fd)
89
90    def __enter__(self):
91        return self
92
93    def __exit__(self, exc_type, exc_val, exc_tb):
94        self.cleanup()
95
96    def _readin(self, offset, buffer):
97        length = os.preadv(self.fd, (buffer,), offset)
98        if len(buffer) != length:
99            raise FileIOException('error: {} failed to read {} bytes at {:x}'
100                            .format(self.filename, len(buffer), offset))
101
102    def _toarray(self, buf):
103        assert(self.element_size == 8)
104        return np.frombuffer(buf, dtype=np.uint64)
105
106    def getv(self, vec):
107        vec *= self.element_size
108        offsets = vec[:, 0]
109        lengths = (np.diff(vec) + self.element_size).reshape(len(vec))
110        buf = bytearray(int(np.sum(lengths)))
111        view = memoryview(buf)
112        pos = 0
113        for offset, length in zip(offsets, lengths):
114            offset = int(offset)
115            length = int(length)
116            self._readin(offset, view[pos:pos+length])
117            pos += length
118        return self._toarray(buf)
119
120    def get(self, index, nr=1):
121        offset = index * self.element_size
122        length = nr * self.element_size
123        buf = bytearray(length)
124        self._readin(offset, buf)
125        return self._toarray(buf)
126
127
128PM_PAGE_PRESENT = 1 << 63
129PM_PFN_MASK = (1 << 55) - 1
130
131class PageMap(BinArrayFile):
132    # Read ranges of a given pid's pagemap into a numpy array.
133    def __init__(self, pid='self'):
134        super().__init__(f'/proc/{pid}/pagemap', 8)
135
136
137KPF_ANON = 1 << 12
138KPF_COMPOUND_HEAD = 1 << 15
139KPF_COMPOUND_TAIL = 1 << 16
140KPF_THP = 1 << 22
141
142class KPageFlags(BinArrayFile):
143    # Read ranges of /proc/kpageflags into a numpy array.
144    def __init__(self):
145         super().__init__(f'/proc/kpageflags', 8)
146
147
148vma_all_stats = set([
149    "Size",
150    "Rss",
151    "Pss",
152    "Pss_Dirty",
153    "Shared_Clean",
154    "Shared_Dirty",
155    "Private_Clean",
156    "Private_Dirty",
157    "Referenced",
158    "Anonymous",
159    "KSM",
160    "LazyFree",
161    "AnonHugePages",
162    "ShmemPmdMapped",
163    "FilePmdMapped",
164    "Shared_Hugetlb",
165    "Private_Hugetlb",
166    "Swap",
167    "SwapPss",
168    "Locked",
169])
170
171vma_min_stats = set([
172    "Rss",
173    "Anonymous",
174    "AnonHugePages",
175    "ShmemPmdMapped",
176    "FilePmdMapped",
177])
178
179VMA = collections.namedtuple('VMA', [
180    'name',
181    'start',
182    'end',
183    'read',
184    'write',
185    'execute',
186    'private',
187    'pgoff',
188    'major',
189    'minor',
190    'inode',
191    'stats',
192])
193
194class VMAList:
195    # A container for VMAs, parsed from /proc/<pid>/smaps. Iterate over the
196    # instance to receive VMAs.
197    def __init__(self, pid='self', stats=[]):
198        self.vmas = []
199        with open(f'/proc/{pid}/smaps', 'r') as file:
200            for line in file:
201                elements = line.split()
202                if '-' in elements[0]:
203                    start, end = map(lambda x: int(x, 16), elements[0].split('-'))
204                    major, minor = map(lambda x: int(x, 16), elements[3].split(':'))
205                    self.vmas.append(VMA(
206                        name=elements[5] if len(elements) == 6 else '',
207                        start=start,
208                        end=end,
209                        read=elements[1][0] == 'r',
210                        write=elements[1][1] == 'w',
211                        execute=elements[1][2] == 'x',
212                        private=elements[1][3] == 'p',
213                        pgoff=int(elements[2], 16),
214                        major=major,
215                        minor=minor,
216                        inode=int(elements[4], 16),
217                        stats={},
218                    ))
219                else:
220                    param = elements[0][:-1]
221                    if param in stats:
222                        value = int(elements[1])
223                        self.vmas[-1].stats[param] = {'type': None, 'value': value}
224
225    def __iter__(self):
226        yield from self.vmas
227
228
229def thp_parse(vma, kpageflags, ranges, indexes, vfns, pfns, anons, heads):
230    # Given 4 same-sized arrays representing a range within a page table backed
231    # by THPs (vfns: virtual frame numbers, pfns: physical frame numbers, anons:
232    # True if page is anonymous, heads: True if page is head of a THP), return a
233    # dictionary of statistics describing the mapped THPs.
234    stats = {
235        'file': {
236            'partial': 0,
237            'aligned': [0] * (PMD_ORDER + 1),
238            'unaligned': [0] * (PMD_ORDER + 1),
239        },
240        'anon': {
241            'partial': 0,
242            'aligned': [0] * (PMD_ORDER + 1),
243            'unaligned': [0] * (PMD_ORDER + 1),
244        },
245    }
246
247    for rindex, rpfn in zip(ranges[0], ranges[2]):
248        index_next = int(rindex[0])
249        index_end = int(rindex[1]) + 1
250        pfn_end = int(rpfn[1]) + 1
251
252        folios = indexes[index_next:index_end][heads[index_next:index_end]]
253
254        # Account pages for any partially mapped THP at the front. In that case,
255        # the first page of the range is a tail.
256        nr = (int(folios[0]) if len(folios) else index_end) - index_next
257        stats['anon' if anons[index_next] else 'file']['partial'] += nr
258
259        # Account pages for any partially mapped THP at the back. In that case,
260        # the next page after the range is a tail.
261        if len(folios):
262            flags = int(kpageflags.get(pfn_end)[0])
263            if flags & KPF_COMPOUND_TAIL:
264                nr = index_end - int(folios[-1])
265                folios = folios[:-1]
266                index_end -= nr
267                stats['anon' if anons[index_end - 1] else 'file']['partial'] += nr
268
269        # Account fully mapped THPs in the middle of the range.
270        if len(folios):
271            folio_nrs = np.append(np.diff(folios), np.uint64(index_end - folios[-1]))
272            folio_orders = np.log2(folio_nrs).astype(np.uint64)
273            for index, order in zip(folios, folio_orders):
274                index = int(index)
275                order = int(order)
276                nr = 1 << order
277                vfn = int(vfns[index])
278                align = 'aligned' if align_forward(vfn, nr) == vfn else 'unaligned'
279                anon = 'anon' if anons[index] else 'file'
280                stats[anon][align][order] += nr
281
282    # Account PMD-mapped THPs spearately, so filter out of the stats. There is a
283    # race between acquiring the smaps stats and reading pagemap, where memory
284    # could be deallocated. So clamp to zero incase it would have gone negative.
285    anon_pmd_mapped = vma.stats['AnonHugePages']['value']
286    file_pmd_mapped = vma.stats['ShmemPmdMapped']['value'] + \
287                      vma.stats['FilePmdMapped']['value']
288    stats['anon']['aligned'][PMD_ORDER] = max(0, stats['anon']['aligned'][PMD_ORDER] - kbnr(anon_pmd_mapped))
289    stats['file']['aligned'][PMD_ORDER] = max(0, stats['file']['aligned'][PMD_ORDER] - kbnr(file_pmd_mapped))
290
291    rstats = {
292        f"anon-thp-pmd-aligned-{odkb(PMD_ORDER)}kB": {'type': 'anon', 'value': anon_pmd_mapped},
293        f"file-thp-pmd-aligned-{odkb(PMD_ORDER)}kB": {'type': 'file', 'value': file_pmd_mapped},
294    }
295
296    def flatten_sub(type, subtype, stats):
297        param = f"{type}-thp-pte-{subtype}-{{}}kB"
298        for od, nr in enumerate(stats[2:], 2):
299            rstats[param.format(odkb(od))] = {'type': type, 'value': nrkb(nr)}
300
301    def flatten_type(type, stats):
302        flatten_sub(type, 'aligned', stats['aligned'])
303        flatten_sub(type, 'unaligned', stats['unaligned'])
304        rstats[f"{type}-thp-pte-partial"] = {'type': type, 'value': nrkb(stats['partial'])}
305
306    flatten_type('anon', stats['anon'])
307    flatten_type('file', stats['file'])
308
309    return rstats
310
311
312def cont_parse(vma, order, ranges, anons, heads):
313    # Given 4 same-sized arrays representing a range within a page table backed
314    # by THPs (vfns: virtual frame numbers, pfns: physical frame numbers, anons:
315    # True if page is anonymous, heads: True if page is head of a THP), return a
316    # dictionary of statistics describing the contiguous blocks.
317    nr_cont = 1 << order
318    nr_anon = 0
319    nr_file = 0
320
321    for rindex, rvfn, rpfn in zip(*ranges):
322        index_next = int(rindex[0])
323        index_end = int(rindex[1]) + 1
324        vfn_start = int(rvfn[0])
325        pfn_start = int(rpfn[0])
326
327        if align_offset(pfn_start, nr_cont) != align_offset(vfn_start, nr_cont):
328            continue
329
330        off = align_forward(vfn_start, nr_cont) - vfn_start
331        index_next += off
332
333        while index_next + nr_cont <= index_end:
334            folio_boundary = heads[index_next+1:index_next+nr_cont].any()
335            if not folio_boundary:
336                if anons[index_next]:
337                    nr_anon += nr_cont
338                else:
339                    nr_file += nr_cont
340            index_next += nr_cont
341
342    # Account blocks that are PMD-mapped spearately, so filter out of the stats.
343    # There is a race between acquiring the smaps stats and reading pagemap,
344    # where memory could be deallocated. So clamp to zero incase it would have
345    # gone negative.
346    anon_pmd_mapped = vma.stats['AnonHugePages']['value']
347    file_pmd_mapped = vma.stats['ShmemPmdMapped']['value'] + \
348                    vma.stats['FilePmdMapped']['value']
349    nr_anon = max(0, nr_anon - kbnr(anon_pmd_mapped))
350    nr_file = max(0, nr_file - kbnr(file_pmd_mapped))
351
352    rstats = {
353        f"anon-cont-pmd-aligned-{nrkb(nr_cont)}kB": {'type': 'anon', 'value': anon_pmd_mapped},
354        f"file-cont-pmd-aligned-{nrkb(nr_cont)}kB": {'type': 'file', 'value': file_pmd_mapped},
355    }
356
357    rstats[f"anon-cont-pte-aligned-{nrkb(nr_cont)}kB"] = {'type': 'anon', 'value': nrkb(nr_anon)}
358    rstats[f"file-cont-pte-aligned-{nrkb(nr_cont)}kB"] = {'type': 'file', 'value': nrkb(nr_file)}
359
360    return rstats
361
362
363def vma_print(vma, pid):
364    # Prints a VMA instance in a format similar to smaps. The main difference is
365    # that the pid is included as the first value.
366    print("{:010d}: {:016x}-{:016x} {}{}{}{} {:08x} {:02x}:{:02x} {:08x} {}"
367        .format(
368            pid, vma.start, vma.end,
369            'r' if vma.read else '-', 'w' if vma.write else '-',
370            'x' if vma.execute else '-', 'p' if vma.private else 's',
371            vma.pgoff, vma.major, vma.minor, vma.inode, vma.name
372        ))
373
374
375def stats_print(stats, tot_anon, tot_file, inc_empty):
376    # Print a statistics dictionary.
377    label_field = 32
378    for label, stat in stats.items():
379        type = stat['type']
380        value = stat['value']
381        if value or inc_empty:
382            pad = max(0, label_field - len(label) - 1)
383            if type == 'anon' and tot_anon > 0:
384                percent = f' ({value / tot_anon:3.0%})'
385            elif type == 'file' and tot_file > 0:
386                percent = f' ({value / tot_file:3.0%})'
387            else:
388                percent = ''
389            print(f"{label}:{' ' * pad}{value:8} kB{percent}")
390
391
392def vma_parse(vma, pagemap, kpageflags, contorders):
393    # Generate thp and cont statistics for a single VMA.
394    start = vma.start >> PAGE_SHIFT
395    end = vma.end >> PAGE_SHIFT
396
397    pmes = pagemap.get(start, end - start)
398    present = pmes & PM_PAGE_PRESENT != 0
399    pfns = pmes & PM_PFN_MASK
400    pfns = pfns[present]
401    vfns = np.arange(start, end, dtype=np.uint64)
402    vfns = vfns[present]
403
404    pfn_vec = cont_ranges_all([pfns], [pfns])[0]
405    flags = kpageflags.getv(pfn_vec)
406    anons = flags & KPF_ANON != 0
407    heads = flags & KPF_COMPOUND_HEAD != 0
408    thps = flags & KPF_THP != 0
409
410    vfns = vfns[thps]
411    pfns = pfns[thps]
412    anons = anons[thps]
413    heads = heads[thps]
414
415    indexes = np.arange(len(vfns), dtype=np.uint64)
416    ranges = cont_ranges_all([vfns, pfns], [indexes, vfns, pfns])
417
418    thpstats = thp_parse(vma, kpageflags, ranges, indexes, vfns, pfns, anons, heads)
419    contstats = [cont_parse(vma, order, ranges, anons, heads) for order in contorders]
420
421    tot_anon = vma.stats['Anonymous']['value']
422    tot_file = vma.stats['Rss']['value'] - tot_anon
423
424    return {
425        **thpstats,
426        **{k: v for s in contstats for k, v in s.items()}
427    }, tot_anon, tot_file
428
429
430def do_main(args):
431    pids = set()
432    rollup = {}
433    rollup_anon = 0
434    rollup_file = 0
435
436    if args.cgroup:
437        strict = False
438        for walk_info in os.walk(args.cgroup):
439            cgroup = walk_info[0]
440            with open(f'{cgroup}/cgroup.procs') as pidfile:
441                for line in pidfile.readlines():
442                    pids.add(int(line.strip()))
443    elif args.pid:
444        strict = True
445        pids = pids.union(args.pid)
446    else:
447        strict = False
448        for pid in os.listdir('/proc'):
449            if pid.isdigit():
450                pids.add(int(pid))
451
452    if not args.rollup:
453        print("       PID             START              END PROT   OFFSET   DEV    INODE OBJECT")
454
455    for pid in pids:
456        try:
457            with PageMap(pid) as pagemap:
458                with KPageFlags() as kpageflags:
459                    for vma in VMAList(pid, vma_all_stats if args.inc_smaps else vma_min_stats):
460                        if (vma.read or vma.write or vma.execute) and vma.stats['Rss']['value'] > 0:
461                            stats, vma_anon, vma_file = vma_parse(vma, pagemap, kpageflags, args.cont)
462                        else:
463                            stats = {}
464                            vma_anon = 0
465                            vma_file = 0
466                        if args.inc_smaps:
467                            stats = {**vma.stats, **stats}
468                        if args.rollup:
469                            for k, v in stats.items():
470                                if k in rollup:
471                                    assert(rollup[k]['type'] == v['type'])
472                                    rollup[k]['value'] += v['value']
473                                else:
474                                    rollup[k] = v
475                            rollup_anon += vma_anon
476                            rollup_file += vma_file
477                        else:
478                            vma_print(vma, pid)
479                            stats_print(stats, vma_anon, vma_file, args.inc_empty)
480        except (FileNotFoundError, ProcessLookupError, FileIOException):
481            if strict:
482                raise
483
484    if args.rollup:
485        stats_print(rollup, rollup_anon, rollup_file, args.inc_empty)
486
487
488def main():
489    docs_width = shutil.get_terminal_size().columns
490    docs_width -= 2
491    docs_width = min(80, docs_width)
492
493    def format(string):
494        text = re.sub(r'\s+', ' ', string)
495        text = re.sub(r'\s*\\n\s*', '\n', text)
496        paras = text.split('\n')
497        paras = [textwrap.fill(p, width=docs_width) for p in paras]
498        return '\n'.join(paras)
499
500    def formatter(prog):
501        return argparse.RawDescriptionHelpFormatter(prog, width=docs_width)
502
503    def size2order(human):
504        units = {
505            "K": 2**10, "M": 2**20, "G": 2**30,
506            "k": 2**10, "m": 2**20, "g": 2**30,
507        }
508        unit = 1
509        if human[-1] in units:
510            unit = units[human[-1]]
511            human = human[:-1]
512        try:
513            size = int(human)
514        except ValueError:
515            raise ArgException('error: --cont value must be integer size with optional KMG unit')
516        size *= unit
517        order = int(math.log2(size / PAGE_SIZE))
518        if order < 1:
519            raise ArgException('error: --cont value must be size of at least 2 pages')
520        if (1 << order) * PAGE_SIZE != size:
521            raise ArgException('error: --cont value must be size of power-of-2 pages')
522        if order > PMD_ORDER:
523            raise ArgException('error: --cont value must be less than or equal to PMD order')
524        return order
525
526    parser = argparse.ArgumentParser(formatter_class=formatter,
527        description=format("""Prints information about how transparent huge
528                    pages are mapped, either system-wide, or for a specified
529                    process or cgroup.\\n
530                    \\n
531                    When run with --pid, the user explicitly specifies the set
532                    of pids to scan. e.g. "--pid 10 [--pid 134 ...]". When run
533                    with --cgroup, the user passes either a v1 or v2 cgroup and
534                    all pids that belong to the cgroup subtree are scanned. When
535                    run with neither --pid nor --cgroup, the full set of pids on
536                    the system is gathered from /proc and scanned as if the user
537                    had provided "--pid 1 --pid 2 ...".\\n
538                    \\n
539                    A default set of statistics is always generated for THP
540                    mappings. However, it is also possible to generate
541                    additional statistics for "contiguous block mappings" where
542                    the block size is user-defined.\\n
543                    \\n
544                    Statistics are maintained independently for anonymous and
545                    file-backed (pagecache) memory and are shown both in kB and
546                    as a percentage of either total anonymous or total
547                    file-backed memory as appropriate.\\n
548                    \\n
549                    THP Statistics\\n
550                    --------------\\n
551                    \\n
552                    Statistics are always generated for fully- and
553                    contiguously-mapped THPs whose mapping address is aligned to
554                    their size, for each <size> supported by the system.
555                    Separate counters describe THPs mapped by PTE vs those
556                    mapped by PMD. (Although note a THP can only be mapped by
557                    PMD if it is PMD-sized):\\n
558                    \\n
559                    - anon-thp-pte-aligned-<size>kB\\n
560                    - file-thp-pte-aligned-<size>kB\\n
561                    - anon-thp-pmd-aligned-<size>kB\\n
562                    - file-thp-pmd-aligned-<size>kB\\n
563                    \\n
564                    Similarly, statistics are always generated for fully- and
565                    contiguously-mapped THPs whose mapping address is *not*
566                    aligned to their size, for each <size> supported by the
567                    system. Due to the unaligned mapping, it is impossible to
568                    map by PMD, so there are only PTE counters for this case:\\n
569                    \\n
570                    - anon-thp-pte-unaligned-<size>kB\\n
571                    - file-thp-pte-unaligned-<size>kB\\n
572                    \\n
573                    Statistics are also always generated for mapped pages that
574                    belong to a THP but where the is THP is *not* fully- and
575                    contiguously- mapped. These "partial" mappings are all
576                    counted in the same counter regardless of the size of the
577                    THP that is partially mapped:\\n
578                    \\n
579                    - anon-thp-pte-partial\\n
580                    - file-thp-pte-partial\\n
581                    \\n
582                    Contiguous Block Statistics\\n
583                    ---------------------------\\n
584                    \\n
585                    An optional, additional set of statistics is generated for
586                    every contiguous block size specified with `--cont <size>`.
587                    These statistics show how much memory is mapped in
588                    contiguous blocks of <size> and also aligned to <size>. A
589                    given contiguous block must all belong to the same THP, but
590                    there is no requirement for it to be the *whole* THP.
591                    Separate counters describe contiguous blocks mapped by PTE
592                    vs those mapped by PMD:\\n
593                    \\n
594                    - anon-cont-pte-aligned-<size>kB\\n
595                    - file-cont-pte-aligned-<size>kB\\n
596                    - anon-cont-pmd-aligned-<size>kB\\n
597                    - file-cont-pmd-aligned-<size>kB\\n
598                    \\n
599                    As an example, if monitoring 64K contiguous blocks (--cont
600                    64K), there are a number of sources that could provide such
601                    blocks: a fully- and contiguously-mapped 64K THP that is
602                    aligned to a 64K boundary would provide 1 block. A fully-
603                    and contiguously-mapped 128K THP that is aligned to at least
604                    a 64K boundary would provide 2 blocks. Or a 128K THP that
605                    maps its first 100K, but contiguously and starting at a 64K
606                    boundary would provide 1 block. A fully- and
607                    contiguously-mapped 2M THP would provide 32 blocks. There
608                    are many other possible permutations.\\n"""),
609        epilog=format("""Requires root privilege to access pagemap and
610                    kpageflags."""))
611
612    group = parser.add_mutually_exclusive_group(required=False)
613    group.add_argument('--pid',
614        metavar='pid', required=False, type=int, default=[], action='append',
615        help="""Process id of the target process. Maybe issued multiple times to
616            scan multiple processes. --pid and --cgroup are mutually exclusive.
617            If neither are provided, all processes are scanned to provide
618            system-wide information.""")
619
620    group.add_argument('--cgroup',
621        metavar='path', required=False,
622        help="""Path to the target cgroup in sysfs. Iterates over every pid in
623            the cgroup and its children. --pid and --cgroup are mutually
624            exclusive. If neither are provided, all processes are scanned to
625            provide system-wide information.""")
626
627    parser.add_argument('--rollup',
628        required=False, default=False, action='store_true',
629        help="""Sum the per-vma statistics to provide a summary over the whole
630            system, process or cgroup.""")
631
632    parser.add_argument('--cont',
633        metavar='size[KMG]', required=False, default=[], action='append',
634        help="""Adds stats for memory that is mapped in contiguous blocks of
635            <size> and also aligned to <size>. May be issued multiple times to
636            track multiple sized blocks. Useful to infer e.g. arm64 contpte and
637            hpa mappings. Size must be a power-of-2 number of pages.""")
638
639    parser.add_argument('--inc-smaps',
640        required=False, default=False, action='store_true',
641        help="""Include all numerical, additive /proc/<pid>/smaps stats in the
642            output.""")
643
644    parser.add_argument('--inc-empty',
645        required=False, default=False, action='store_true',
646        help="""Show all statistics including those whose value is 0.""")
647
648    parser.add_argument('--periodic',
649        metavar='sleep_ms', required=False, type=int,
650        help="""Run in a loop, polling every sleep_ms milliseconds.""")
651
652    args = parser.parse_args()
653
654    try:
655        args.cont = [size2order(cont) for cont in args.cont]
656    except ArgException as e:
657        parser.print_usage()
658        raise
659
660    if args.periodic:
661        while True:
662            do_main(args)
663            print()
664            time.sleep(args.periodic / 1000)
665    else:
666        do_main(args)
667
668
669if __name__ == "__main__":
670    try:
671        main()
672    except Exception as e:
673        prog = os.path.basename(sys.argv[0])
674        print(f'{prog}: {e}')
675        exit(1)
676