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 python3
#
# Copyright 2014 Olivia Mackall <olivia@selenic.com>
#
# A tool/hook to run basic sanity checks on commits/patches for
# submission to Mercurial. Install by adding the following to your
# .hg/hgrc:
#
# [hooks]
# pretxncommit = contrib/check-commit
#
# The hook can be temporarily bypassed with:
#
# $ BYPASS= hg commit
#
# See also: https://mercurial-scm.org/wiki/ContributingChanges
import os
import re
import sys
commitheader = r"^(?:# [^\n]*\n)*"
afterheader = commitheader + r"(?!#)"
beforepatch = afterheader + r"(?!\n(?!@@))"
errors = [
(beforepatch + r".*[(]bc[)]", "(BC) needs to be uppercase"),
(
beforepatch + r".*[(]issue \d\d\d",
"no space allowed between issue and number",
),
(beforepatch + r".*[(]bug(\d|\s)", "use (issueDDDD) instead of bug"),
(commitheader + r"# User [^@\n]+\n", "username is not an email address"),
(
commitheader + r"(?!merge with )[^#]\S+[^:] ",
"summary line doesn't start with 'topic: '",
),
(afterheader + r"[A-Z][a-z]\S+", "don't capitalize summary lines"),
(afterheader + r"^\S+: *[A-Z][a-z]\S+", "don't capitalize summary lines"),
(
afterheader + r"\S*[^A-Za-z0-9-_]\S*: ",
"summary keyword should be most user-relevant one-word command or topic",
),
(afterheader + r".*\.\s*\n", "don't add trailing period on summary line"),
(afterheader + r".{79,}", "summary line too long (limit is 78)"),
]
word = re.compile(r'\S')
def nonempty(first, second):
if word.search(first):
return first
return second
def checkcommit(commit, node=None):
exitcode = 0
printed = node is None
hits = []
signtag = (
afterheader + r'Added (tag [^ ]+|signature) for changeset [a-f0-9]{12}'
)
if re.search(signtag, commit):
return 0
for exp, msg in errors:
for m in re.finditer(exp, commit):
end = m.end()
trailing = re.search(r'(\\n)+$', exp)
if trailing:
end -= len(trailing.group()) / 2
hits.append((end, exp, msg))
if hits:
hits.sort()
pos = 0
last = ''
for n, l in enumerate(commit.splitlines(True)):
pos += len(l)
while len(hits):
end, exp, msg = hits[0]
if pos < end:
break
if not printed:
printed = True
print("node: %s" % node)
print("%d: %s" % (n, msg))
print(" %s" % nonempty(l, last)[:-1])
if "BYPASS" not in os.environ:
exitcode = 1
del hits[0]
last = nonempty(l, last)
return exitcode
def readcommit(node):
return os.popen("hg export %s" % node).read()
if __name__ == "__main__":
exitcode = 0
node = os.environ.get("HG_NODE")
if node:
commit = readcommit(node)
exitcode = checkcommit(commit)
elif sys.argv[1:]:
for node in sys.argv[1:]:
exitcode |= checkcommit(readcommit(node), node)
else:
commit = sys.stdin.read()
exitcode = checkcommit(commit)
sys.exit(exitcode)