perf: clear vfs audit_cache before each run
When generating a stream clone, we spend a large amount of time auditing path.
Before this changes, the first run was warming the vfs cache for the other
runs, leading to a large runtime difference and a "faulty" reported timing for
the operation.
We now clear this important cache between run to get a more realistic timing.
Below are some example of median time change when clearing these cases. The
maximum time for a run did not changed significantly.
### data-env-vars.name = mozilla-central-2018-08-01-zstd-sparse-revlog
# benchmark.name = hg.perf.exchange.stream.generate
# bin-env-vars.hg.flavor = default
# bin-env-vars.hg.py-re2-module = default
# benchmark.variants.version = latest
no-clearing: 17.289905
cache-clearing: 21.587965 (+24.86%, +4.30)
## data-env-vars.name = mozilla-central-2024-03-22-zstd-sparse-revlog
no-clearing: 32.670748
cache-clearing: 40.467095 (+23.86%, +7.80)
## data-env-vars.name = mozilla-try-2019-02-18-zstd-sparse-revlog
no-clearing: 37.838858
cache-clearing: 46.072749 (+21.76%, +8.23)
## data-env-vars.name = mozilla-unified-2024-03-22-zstd-sparse-revlog
no-clearing: 32.969395
cache-clearing: 39.646209 (+20.25%, +6.68)
In addition, this significantly reduce the timing difference between the
performance command, from the perf extensions and a `real `hg bundle` call
producing a stream bundle. Some significant differences remain especially on
the "mozilla-try" repositories, but they are now smaller.
Note that some of that difference will actually not be
attributable to the stream generation (like maybe phases or branch map
computation).
Below are some benchmarks done on a currently draft changeset fixing some
unrelated slowness in `hg bundle` (34a78972af409d1ff37c29e60f6ca811ad1a457d)
### data-env-vars.name = mozilla-central-2018-08-01-zstd-sparse-revlog
# bin-env-vars.hg.flavor = default
# bin-env-vars.hg.py-re2-module = default
hg.perf.exchange.stream.generate: 21.587965
hg.command.bundle: 24.301799 (+12.57%, +2.71)
## data-env-vars.name = mozilla-central-2024-03-22-zstd-sparse-revlog
hg.perf.exchange.stream.generate: 40.467095
hg.command.bundle: 44.831317 (+10.78%, +4.36)
## data-env-vars.name = mozilla-unified-2024-03-22-zstd-sparse-revlog
hg.perf.exchange.stream.generate: 39.646209
hg.command.bundle: 45.395258 (+14.50%, +5.75)
## data-env-vars.name = mozilla-try-2019-02-18-zstd-sparse-revlog
hg.perf.exchange.stream.generate: 46.072749
hg.command.bundle: 55.882608 (+21.29%, +9.81)
## data-env-vars.name = mozilla-try-2023-03-22-zlib-general-delta
hg.perf.exchange.stream.generate: 334.716708
hg.command.bundle: 377.856767 (+12.89%, +43.14)
## data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog
hg.perf.exchange.stream.generate: 302.972301
hg.command.bundle: 326.098755 (+7.63%, +23.13)
#!/usr/bin/env python2
import argparse
import os
import subprocess
import sys
try:
# Always load hg libraries from the hg we can find on $PATH.
hglib = subprocess.check_output(['hg', 'debuginstall', '-T', '{hgmodules}'])
sys.path.insert(0, os.path.dirname(hglib))
except subprocess.CalledProcessError:
# We're probably running with a PyOxidized Mercurial, so just
# proceed and hope it works out okay.
pass
from mercurial import util
ap = argparse.ArgumentParser()
ap.add_argument(
'--paranoid',
action='store_true',
help=(
"Be paranoid about how version numbers compare and "
"produce something that's more likely to sort "
"reasonably."
),
)
ap.add_argument('--selftest', action='store_true', help='Run self-tests.')
ap.add_argument('versionfile', help='Path to a valid mercurial __version__.py')
def paranoidver(ver):
"""Given an hg version produce something that distutils can sort.
Some Mac package management systems use distutils code in order to
figure out upgrades, which makes life difficult. The test case is
a reduced version of code in the Munki tool used by some large
organizations to centrally manage OS X packages, which is what
inspired this kludge.
>>> paranoidver('3.4')
'3.4.0'
>>> paranoidver('3.4.2')
'3.4.2'
>>> paranoidver('3.0-rc+10')
'2.9.9999-rc+10'
>>> paranoidver('4.2+483-5d44d7d4076e')
'4.2.0+483-5d44d7d4076e'
>>> paranoidver('4.2.1+598-48d1e1214d8c')
'4.2.1+598-48d1e1214d8c'
>>> paranoidver('4.3-rc')
'4.2.9999-rc'
>>> paranoidver('4.3')
'4.3.0'
>>> from distutils import version
>>> class LossyPaddedVersion(version.LooseVersion):
... '''Subclass version.LooseVersion to compare things like
... "10.6" and "10.6.0" as equal'''
... def __init__(self, s):
... self.parse(s)
...
... def _pad(self, version_list, max_length):
... 'Pad a version list by adding extra 0 components to the end'
... # copy the version_list so we don't modify it
... cmp_list = list(version_list)
... while len(cmp_list) < max_length:
... cmp_list.append(0)
... return cmp_list
...
... def __cmp__(self, other):
... if isinstance(other, str):
... other = MunkiLooseVersion(other)
... max_length = max(len(self.version), len(other.version))
... self_cmp_version = self._pad(self.version, max_length)
... other_cmp_version = self._pad(other.version, max_length)
... return cmp(self_cmp_version, other_cmp_version)
>>> def testver(older, newer):
... o = LossyPaddedVersion(paranoidver(older))
... n = LossyPaddedVersion(paranoidver(newer))
... return o < n
>>> testver('3.4', '3.5')
True
>>> testver('3.4.0', '3.5-rc')
True
>>> testver('3.4-rc', '3.5')
True
>>> testver('3.4-rc+10-deadbeef', '3.5')
True
>>> testver('3.4.2', '3.5-rc')
True
>>> testver('3.4.2', '3.5-rc+10-deadbeef')
True
>>> testver('4.2+483-5d44d7d4076e', '4.2.1+598-48d1e1214d8c')
True
>>> testver('4.3-rc', '4.3')
True
>>> testver('4.3', '4.3-rc')
False
"""
major, minor, micro, extra = util.versiontuple(ver, n=4)
if micro is None:
micro = 0
if extra:
if extra.startswith('rc'):
if minor == 0:
major -= 1
minor = 9
else:
minor -= 1
micro = 9999
extra = '-' + extra
else:
extra = '+' + extra
else:
extra = ''
return '%d.%d.%d%s' % (major, minor, micro, extra)
def main(argv):
opts = ap.parse_args(argv[1:])
if opts.selftest:
import doctest
doctest.testmod()
return
with open(opts.versionfile) as f:
for l in f:
if l.startswith('version = b'):
# version number is entire line minus the quotes
ver = l[len('version = b') + 1 : -2]
break
if opts.paranoid:
print(paranoidver(ver))
else:
print(ver)
if __name__ == '__main__':
main(sys.argv)