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)
#require no-windows
$ . "$TESTDIR/remotefilelog-library.sh"
$ hg init master
$ cd master
$ echo treemanifest >> .hg/requires
$ cat >> .hg/hgrc <<EOF
> [remotefilelog]
> server=True
> EOF
# uppercase directory name to test encoding
$ mkdir -p A/B
$ echo x > A/B/x
$ hg commit -qAm x
$ cd ..
# shallow clone from full
$ hgcloneshallow ssh://user@dummy/master shallow --noupdate
streaming all changes
5 files to transfer, 449 bytes of data (no-rust !)
transferred 449 bytes in * seconds (*/sec) (glob) (no-rust !)
7 files to transfer, 575 bytes of data (rust !)
transferred 575 bytes in *.* seconds (*) (glob) (rust !)
searching for changes
no changes found
$ cd shallow
$ hg debugrequires
dotencode
dirstate-v2 (dirstate-v2 !)
exp-remotefilelog-repo-req-1
fncache
generaldelta
persistent-nodemap (rust !)
revlog-compression-zstd (zstd !)
revlogv1
share-safe
sparserevlog
store
treemanifest
$ find .hg/store/meta | sort
.hg/store/meta
.hg/store/meta/_a
.hg/store/meta/_a/00manifest.i
.hg/store/meta/_a/_b
.hg/store/meta/_a/_b/00manifest.i
$ hg update
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
$ cat A/B/x
x
$ ls .hg/store/data
$ echo foo > A/B/F
$ hg add A/B/F
$ hg ci -m 'local content'
$ ls .hg/store/data
ca31988f085bfb945cb8115b78fabdee40f741aa
$ cd ..
# shallow clone from shallow
$ hgcloneshallow ssh://user@dummy/shallow shallow2 --noupdate
streaming all changes
6 files to transfer, 1008 bytes of data (no-rust !)
transferred 1008 bytes in * seconds (*/sec) (glob) (no-rust !)
8 files to transfer, 1.11 KB of data (rust !)
transferred 1.11 KB in * seconds (* */sec) (glob) (rust !)
searching for changes
no changes found
$ cd shallow2
$ hg debugrequires
dotencode
dirstate-v2 (dirstate-v2 !)
exp-remotefilelog-repo-req-1
fncache
generaldelta
persistent-nodemap (rust !)
revlog-compression-zstd (zstd !)
revlogv1
share-safe
sparserevlog
store
treemanifest
$ ls .hg/store/data
ca31988f085bfb945cb8115b78fabdee40f741aa
$ hg update
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cat A/B/x
x
$ cd ..
# full clone from shallow
# - send stderr to /dev/null because the order of stdout/err causes
# flakiness here
$ hg clone --noupdate ssh://user@dummy/shallow full 2>/dev/null
streaming all changes
[100]
# getbundle full clone
$ printf '[server]\npreferuncompressed=False\n' >> master/.hg/hgrc
$ hgcloneshallow ssh://user@dummy/master shallow3
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 0 changes to 0 files
new changesets 18d955ee7ba0
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ ls shallow3/.hg/store/data
$ hg debugrequires -R shallow3/
dotencode
dirstate-v2 (dirstate-v2 !)
exp-remotefilelog-repo-req-1
fncache
generaldelta
persistent-nodemap (rust !)
revlog-compression-zstd (zstd !)
revlogv1
share-safe
sparserevlog
store
treemanifest