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)
setup
$ cat >> $HGRCPATH <<EOF
> [extensions]
> share =
> [format]
> use-share-safe = True
> [storage]
> revlog.persistent-nodemap.slow-path=allow
> # enforce zlib to ensure we can upgrade to zstd later
> [format]
> revlog-compression=zlib
> # we want to be able to enable it later
> use-persistent-nodemap=no
> EOF
prepare source repo
$ hg init source
$ cd source
$ cat .hg/requires
dirstate-v2 (dirstate-v2 !)
share-safe
$ cat .hg/store/requires
dotencode
fncache
generaldelta
revlogv1
sparserevlog
store
$ hg debugrequirements
dotencode
dirstate-v2 (dirstate-v2 !)
fncache
generaldelta
revlogv1
share-safe
sparserevlog
store
$ echo a > a
$ hg ci -Aqm "added a"
$ echo b > b
$ hg ci -Aqm "added b"
$ HGEDITOR=cat hg config --shared
abort: repository is not shared; can't use --shared
[10]
$ cd ..
Create a shared repo and check the requirements are shared and read correctly
$ hg share source shared1
updating working directory
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd shared1
$ cat .hg/requires
dirstate-v2 (dirstate-v2 !)
share-safe
shared
$ hg debugrequirements -R ../source
dotencode
dirstate-v2 (dirstate-v2 !)
fncache
generaldelta
revlogv1
share-safe
sparserevlog
store
$ hg debugrequirements
dotencode
dirstate-v2 (dirstate-v2 !)
fncache
generaldelta
revlogv1
share-safe
shared
sparserevlog
store
$ echo c > c
$ hg ci -Aqm "added c"
Check that config of the source repository is also loaded
$ hg showconfig ui.curses
[1]
$ echo "[ui]" >> ../source/.hg/hgrc
$ echo "curses=true" >> ../source/.hg/hgrc
$ hg showconfig ui.curses
true
Test that extensions of source repository are also loaded
$ hg debugextensions
share
$ hg extdiff -p echo
hg: unknown command 'extdiff'
'extdiff' is provided by the following extension:
extdiff command to allow external programs to compare revisions
(use 'hg help extensions' for information on enabling extensions)
[10]
$ echo "[extensions]" >> ../source/.hg/hgrc
$ echo "extdiff=" >> ../source/.hg/hgrc
$ hg debugextensions -R ../source
extdiff
share
$ hg extdiff -R ../source -p echo
BROKEN: the command below will not work if config of shared source is not loaded
on dispatch but debugextensions says that extension
is loaded
$ hg debugextensions
extdiff
share
$ hg extdiff -p echo
However, local .hg/hgrc should override the config set by share source
$ echo "[ui]" >> .hg/hgrc
$ echo "curses=false" >> .hg/hgrc
$ hg showconfig ui.curses
false
$ HGEDITOR=cat hg config --shared
[ui]
curses=true
[extensions]
extdiff=
$ HGEDITOR=cat hg config --local
[ui]
curses=false
Testing that hooks set in source repository also runs in shared repo
$ cd ../source
$ cat <<EOF >> .hg/hgrc
> [extensions]
> hooklib=
> [hooks]
> pretxnchangegroup.reject_merge_commits = \
> python:hgext.hooklib.reject_merge_commits.hook
> EOF
$ cd ..
$ hg clone source cloned
updating to branch default
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd cloned
$ hg up 0
0 files updated, 0 files merged, 2 files removed, 0 files unresolved
$ echo bar > bar
$ hg ci -Aqm "added bar"
$ hg merge
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -m "merge commit"
$ hg push ../source
pushing to ../source
searching for changes
adding changesets
adding manifests
adding file changes
error: pretxnchangegroup.reject_merge_commits hook failed: bcde3522682d rejected as merge on the same branch. Please consider rebase.
transaction abort!
rollback completed
abort: bcde3522682d rejected as merge on the same branch. Please consider rebase.
[255]
$ hg push ../shared1
pushing to ../shared1
searching for changes
adding changesets
adding manifests
adding file changes
error: pretxnchangegroup.reject_merge_commits hook failed: bcde3522682d rejected as merge on the same branch. Please consider rebase.
transaction abort!
rollback completed
abort: bcde3522682d rejected as merge on the same branch. Please consider rebase.
[255]
Test that if share source config is untrusted, we dont read it
$ cd ../shared1
$ cat << EOF > $TESTTMP/untrusted.py
> from mercurial import scmutil, util
> def uisetup(ui):
> class untrustedui(ui.__class__):
> def _trusted(self, fp, f):
> if util.normpath(fp.name).endswith(b'source/.hg/hgrc'):