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)

  $ cat <<EOF >> $HGRCPATH
  > [extensions]
  > convert =
  > [convert]
  > hg.tagsbranch = 0
  > EOF
  $ hg init source
  $ cd source
  $ echo a > a
  $ hg ci -qAm adda

Add a merge with one parent in the same branch

  $ echo a >> a
  $ hg ci -qAm changea
  $ hg up -qC 0
  $ hg branch branch0
  marked working directory as branch branch0
  (branches are permanent and global, did you want a bookmark?)
  $ echo b > b
  $ hg ci -qAm addb
  $ hg up -qC
  $ hg merge default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -qm mergeab
  $ hg tag -ql mergeab
  $ cd ..

Miss perl... sometimes

  $ cat > filter.py <<EOF
  > import re
  > import sys
  > 
  > r = re.compile(r'^(?:\d+|pulling from)')
  > sys.stdout.writelines([l for l in sys.stdin if r.search(l)])
  > EOF

convert

  $ hg convert -v --config convert.hg.clonebranches=1 source dest |
  >     "$PYTHON" filter.py
  3 adda
  2 changea
  1 addb
  pulling from default into branch0
  1 changesets found
  0 mergeab
  pulling from default into branch0
  1 changesets found

Add a merge with both parents and child in different branches

  $ cd source
  $ hg branch branch1
  marked working directory as branch branch1
  $ echo a > file1
  $ hg ci -qAm c1
  $ hg up -qC mergeab
  $ hg branch branch2
  marked working directory as branch branch2
  $ echo a > file2
  $ hg ci -qAm c2
  $ hg merge branch1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg branch branch3
  marked working directory as branch branch3
  $ hg ci -qAm c3
  $ cd ..

incremental conversion

  $ hg convert -v --config convert.hg.clonebranches=1 source dest |
  >     "$PYTHON" filter.py
  2 c1
  pulling from branch0 into branch1
  4 changesets found
  1 c2
  pulling from branch0 into branch2
  4 changesets found
  0 c3
  pulling from branch1 into branch3
  5 changesets found
  pulling from branch2 into branch3
  1 changesets found