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)
$ echo "[extensions]" >> $HGRCPATH
$ echo "rebase=" >> $HGRCPATH
initialize repository
$ hg init repo
$ cd repo
$ echo 'a' > a
$ hg ci -A -m "0"
adding a
$ echo 'b' > b
$ hg ci -A -m "1"
adding b
$ hg up 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo 'c' > c
$ hg ci -A -m "2"
adding c
created new head
$ echo 'd' > d
$ hg ci -A -m "3"
adding d
$ hg bookmark -r 1 one
$ hg bookmark -r 3 two
$ hg up -q two
bookmark list
$ hg bookmark
one 1:925d80f479bb
* two 3:2ae46b1d99a7
rebase
$ hg rebase -s two -d one
rebasing 3:2ae46b1d99a7 two tip "3"
saved backup bundle to $TESTTMP/repo/.hg/strip-backup/2ae46b1d99a7-e6b057bc-rebase.hg
$ hg log
changeset: 3:42e5ed2cdcf4
bookmark: two
tag: tip
parent: 1:925d80f479bb
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 3
changeset: 2:db815d6d32e6
parent: 0:f7b1eb17ad24
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 2
changeset: 1:925d80f479bb
bookmark: one
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 1
changeset: 0:f7b1eb17ad24
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 0
aborted rebase should restore active bookmark.
$ hg up 1
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
(leaving bookmark two)
$ echo 'e' > d
$ hg ci -A -m "4"
adding d
created new head
$ hg bookmark three
$ hg rebase -s three -d two
rebasing 4:dd7c838e8362 three tip "4"
merging d
warning: conflicts while merging d! (edit, then use 'hg resolve --mark')
unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
[240]
$ hg rebase --abort
rebase aborted
$ hg bookmark
one 1:925d80f479bb
* three 4:dd7c838e8362
two 3:42e5ed2cdcf4
after aborted rebase, restoring a bookmark that has been removed should not fail
$ hg rebase -s three -d two
rebasing 4:dd7c838e8362 three tip "4"
merging d
warning: conflicts while merging d! (edit, then use 'hg resolve --mark')
unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
[240]
$ hg bookmark -d three
$ hg rebase --abort
rebase aborted
$ hg bookmark
one 1:925d80f479bb
two 3:42e5ed2cdcf4