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 hardlink reporevlogstore
$ cat > nlinks.py <<EOF
> import sys
> from mercurial import pycompat, util
> for f in sorted(sys.stdin.readlines()):
> f = f[:-1]
> print(util.nlinks(pycompat.fsencode(f)), f)
> EOF
$ nlinksdir()
> {
> find "$@" -type f | "$PYTHON" $TESTTMP/nlinks.py
> }
Some implementations of cp can't create hardlinks (replaces 'cp -al' on Linux):
$ cat > linkcp.py <<EOF
> import sys
> from mercurial import pycompat, util
> util.copyfiles(pycompat.fsencode(sys.argv[1]),
> pycompat.fsencode(sys.argv[2]), hardlink=True)
> EOF
$ linkcp()
> {
> "$PYTHON" $TESTTMP/linkcp.py $1 $2
> }
Prepare repo r1:
$ hg init r1
$ cd r1
$ echo c1 > f1
$ hg add f1
$ hg ci -m0
$ mkdir d1
$ cd d1
$ echo c2 > f2
$ hg add f2
$ hg ci -m1
$ cd ../..
$ nlinksdir r1/.hg/store
1 r1/.hg/store/00changelog-b870a51b.nd (rust !)
1 r1/.hg/store/00changelog.d
1 r1/.hg/store/00changelog.i
1 r1/.hg/store/00changelog.n (rust !)
1 r1/.hg/store/00manifest.i
1 r1/.hg/store/data/d1/f2.i
1 r1/.hg/store/data/f1.i
1 r1/.hg/store/fncache (repofncache !)
1 r1/.hg/store/phaseroots
1 r1/.hg/store/requires
1 r1/.hg/store/undo
1 r1/.hg/store/undo.backup.00changelog.n.bck (rust !)
1 r1/.hg/store/undo.backup.fncache.bck (repofncache !)
1 r1/.hg/store/undo.backupfiles
Create hardlinked clone r2:
$ hg clone -U --debug r1 r2 --config progress.debug=true
linking: 1/8 files (12.50%) (no-rust !)
linking: 2/8 files (25.00%) (no-rust !)
linking: 3/8 files (37.50%) (no-rust !)
linking: 4/8 files (50.00%) (no-rust !)
linking: 5/8 files (62.50%) (no-rust !)
linking: 6/8 files (75.00%) (no-rust !)
linking: 7/8 files (87.50%) (no-rust !)
linking: 8/8 files (100.00%) (no-rust !)
linked 8 files (no-rust !)
linking: 1/10 files (10.00%) (rust !)
linking: 2/10 files (20.00%) (rust !)
linking: 3/10 files (30.00%) (rust !)
linking: 4/10 files (40.00%) (rust !)
linking: 5/10 files (50.00%) (rust !)
linking: 6/10 files (60.00%) (rust !)
linking: 7/10 files (70.00%) (rust !)
linking: 8/10 files (80.00%) (rust !)
linking: 9/10 files (90.00%) (rust !)
linking: 10/10 files (100.00%) (rust !)
linked 10 files (rust !)
updating the branch cache
Create non-hardlinked clone r3:
$ hg clone --pull r1 r3
requesting all changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 2 files
new changesets 40d85e9847f2:7069c422939c
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
Repos r1 and r2 should now contain hardlinked files:
$ nlinksdir r1/.hg/store
1 r1/.hg/store/00changelog-b870a51b.nd (rust !)
2 r1/.hg/store/00changelog.d
2 r1/.hg/store/00changelog.i
1 r1/.hg/store/00changelog.n (rust !)
2 r1/.hg/store/00manifest.i
2 r1/.hg/store/data/d1/f2.i
2 r1/.hg/store/data/f1.i
1 r1/.hg/store/fncache (repofncache !)
1 r1/.hg/store/phaseroots
1 r1/.hg/store/requires
1 r1/.hg/store/undo
1 r1/.hg/store/undo.backup.00changelog.n.bck (rust !)
1 r1/.hg/store/undo.backup.fncache.bck (repofncache !)
1 r1/.hg/store/undo.backupfiles
$ nlinksdir r2/.hg/store
1 r2/.hg/store/00changelog-b870a51b.nd (rust !)
2 r2/.hg/store/00changelog.d
2 r2/.hg/store/00changelog.i
1 r2/.hg/store/00changelog.n (rust !)
2 r2/.hg/store/00manifest.i
2 r2/.hg/store/data/d1/f2.i
2 r2/.hg/store/data/f1.i
1 r2/.hg/store/fncache (repofncache !)
1 r2/.hg/store/requires
Repo r3 should not be hardlinked:
$ nlinksdir r3/.hg/store
1 r3/.hg/store/00changelog-88698448.nd (rust !)
1 r3/.hg/store/00changelog.d
1 r3/.hg/store/00changelog.i
1 r3/.hg/store/00changelog.n (rust !)
1 r3/.hg/store/00manifest.i
1 r3/.hg/store/data/d1/f2.i
1 r3/.hg/store/data/f1.i
1 r3/.hg/store/fncache (repofncache !)
1 r3/.hg/store/phaseroots
1 r3/.hg/store/requires
1 r3/.hg/store/undo
1 r3/.hg/store/undo.backupfiles
Create a non-inlined filelog in r3:
$ cd r3/d1
>>> f = open('data1', 'wb')
>>> for x in range(10000):
... f.write(b"%d\n" % x) and None
>>> f.close()
$ for j in 0 1 2 3 4 5 6 7 8 9; do
> cat data1 >> f2
> hg commit -m$j
> done
$ cd ../..
$ nlinksdir r3/.hg/store
1 r3/.hg/store/00changelog-ea337809.nd (rust !)
1 r3/.hg/store/00changelog.d
1 r3/.hg/store/00changelog.i
1 r3/.hg/store/00changelog.n (rust !)
1 r3/.hg/store/00manifest.i
1 r3/.hg/store/data/d1/f2.d
1 r3/.hg/store/data/d1/f2.i
1 r3/.hg/store/data/f1.i
1 r3/.hg/store/fncache (repofncache !)
1 r3/.hg/store/phaseroots
1 r3/.hg/store/requires
1 r3/.hg/store/undo
1 r3/.hg/store/undo.backup.00changelog.n.bck (rust !)
1 r3/.hg/store/undo.backupfiles
Push to repo r1 should break up most hardlinks in r2:
$ hg -R r2 verify -q
$ cd r3
$ hg push
pushing to $TESTTMP/r1
searching for changes
adding changesets
adding manifests
adding file changes
added 10 changesets with 10 changes to 1 files
$ cd ..
$ nlinksdir r2/.hg/store
1 r2/.hg/store/00changelog-b870a51b.nd (rust !)
1 r2/.hg/store/00changelog.d
1 r2/.hg/store/00changelog.i
1 r2/.hg/store/00changelog.n (rust !)
1 r2/.hg/store/00manifest.i
1 r2/.hg/store/data/d1/f2.i
2 r2/.hg/store/data/f1.i
[12] r2/\.hg/store/fncache (re) (repofncache !)
1 r2/.hg/store/requires
#if hardlink-whitelisted repofncache
$ nlinksdir r2/.hg/store/fncache
1 r2/.hg/store/fncache
#endif
$ hg -R r2 verify -q
$ cd r1
$ hg up
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
Committing a change to f1 in r1 must break up hardlink f1.i in r2:
$ echo c1c1 >> f1
$ hg ci -m00
$ cd ..
$ nlinksdir r2/.hg/store
1 r2/.hg/store/00changelog-b870a51b.nd (rust !)
1 r2/.hg/store/00changelog.d
1 r2/.hg/store/00changelog.i
1 r2/.hg/store/00changelog.n (rust !)
1 r2/.hg/store/00manifest.i
1 r2/.hg/store/data/d1/f2.i
1 r2/.hg/store/data/f1.i
1 r2/.hg/store/fncache (repofncache !)
1 r2/.hg/store/requires
#if hardlink-whitelisted repofncache
$ nlinksdir r2/.hg/store/fncache
1 r2/.hg/store/fncache
#endif
Create a file which exec permissions we will change
$ cd r3
$ echo "echo hello world" > f3
$ hg add f3
$ hg ci -mf3
$ cd ..
$ cd r3
$ hg tip --template '{rev}:{node|short}\n'
12:d3b77733a28a
$ echo bla > f1
$ chmod +x f3
$ hg ci -m1
$ cd ..
Create hardlinked copy r4 of r3 (on Linux, we would call 'cp -al'):
$ linkcp r3 r4
'checklink' is produced by hardlinking a symlink, which is undefined whether
the symlink should be followed or not. It does behave differently on Linux and
BSD. Just remove it so the test pass on both platforms.
$ rm -f r4/.hg/wcache/checklink
r4 has hardlinks in the working dir (not just inside .hg):
$ nlinksdir r4
2 r4/.hg/00changelog.i
[24] r4/.hg/branch (re)
2 r4/.hg/cache/branch2-base
2 r4/.hg/cache/branch2-served
2 r4/.hg/cache/rbc-names-v1
2 r4/.hg/cache/rbc-revs-v1
2 r4/.hg/cache/tags2
2 r4/.hg/cache/tags2-served
2 r4/.hg/dirstate
2 r4/.hg/fsmonitor.state (fsmonitor !)
2 r4/.hg/hgrc
2 r4/.hg/last-message.txt
2 r4/.hg/requires
2 r4/.hg/store/00changelog-7f2eb713.nd (rust !)
2 r4/.hg/store/00changelog.d
2 r4/.hg/store/00changelog.i
2 r4/.hg/store/00changelog.n (rust !)
2 r4/.hg/store/00manifest.i
2 r4/.hg/store/data/d1/f2.d
2 r4/.hg/store/data/d1/f2.i
2 r4/.hg/store/data/f1.i
2 r4/.hg/store/data/f3.i
2 r4/.hg/store/fncache (repofncache !)
2 r4/.hg/store/phaseroots
2 r4/.hg/store/requires
2 r4/.hg/store/undo
2 r4/.hg/store/undo.backup.00changelog.n.bck (rust !)
2 r4/.hg/store/undo.backupfiles
[24] r4/.hg/undo.backup.branch.bck (re)
2 r4/\.hg/undo\.backup\.dirstate.bck (re)
2 r4/.hg/undo.desc
2 r4/.hg/wcache/checkisexec (execbit !)
2 r4/.hg/wcache/checklink-target (symlink !)
2 r4/.hg/wcache/checknoexec (execbit !)
2 r4/.hg/wcache/manifestfulltextcache (reporevlogstore !)
2 r4/d1/data1
2 r4/d1/f2
2 r4/f1
2 r4/f3
Update back to revision 12 in r4 should break hardlink of file f1 and f3:
#if hardlink-whitelisted
$ nlinksdir r4/.hg/undo.backup.dirstate.bck r4/.hg/dirstate
2 r4/.hg/dirstate
2 r4/.hg/undo.backup.dirstate.bck
#endif
$ hg -R r4 up 12
2 files updated, 0 files merged, 0 files removed, 0 files unresolved (execbit !)
1 files updated, 0 files merged, 0 files removed, 0 files unresolved (no-execbit !)
$ nlinksdir r4
2 r4/.hg/00changelog.i
1 r4/.hg/branch
2 r4/.hg/cache/branch2-base
2 r4/.hg/cache/branch2-served
2 r4/.hg/cache/rbc-names-v1
2 r4/.hg/cache/rbc-revs-v1
2 r4/.hg/cache/tags2
2 r4/.hg/cache/tags2-served
1 r4/.hg/dirstate
1 r4/.hg/fsmonitor.state (fsmonitor !)
2 r4/.hg/hgrc
2 r4/.hg/last-message.txt
2 r4/.hg/requires
2 r4/.hg/store/00changelog-7f2eb713.nd (rust !)
2 r4/.hg/store/00changelog.d
2 r4/.hg/store/00changelog.i
2 r4/.hg/store/00changelog.n (rust !)
2 r4/.hg/store/00manifest.i
2 r4/.hg/store/data/d1/f2.d
2 r4/.hg/store/data/d1/f2.i
2 r4/.hg/store/data/f1.i
2 r4/.hg/store/data/f3.i
2 r4/.hg/store/fncache
2 r4/.hg/store/phaseroots
2 r4/.hg/store/requires
2 r4/.hg/store/undo
2 r4/.hg/store/undo.backup.00changelog.n.bck (rust !)
2 r4/.hg/store/undo.backupfiles
[23] r4/.hg/undo.backup.branch.bck (re)
2 r4/\.hg/undo\.backup\.dirstate.bck (re)
2 r4/.hg/undo.desc
2 r4/.hg/wcache/checkisexec (execbit !)
2 r4/.hg/wcache/checklink-target (symlink !)
2 r4/.hg/wcache/checknoexec (execbit !)
1 r4/.hg/wcache/manifestfulltextcache (reporevlogstore !)
2 r4/d1/data1
2 r4/d1/f2
1 r4/f1
1 r4/f3 (execbit !)
2 r4/f3 (no-execbit !)
#if hardlink-whitelisted
$ nlinksdir r4/.hg/undo.backup.dirstate.bck r4/.hg/dirstate
1 r4/.hg/dirstate
2 r4/.hg/undo.backup.dirstate.bck
#endif
Test hardlinking outside hg:
$ mkdir x
$ echo foo > x/a
$ linkcp x y
$ echo bar >> y/a
No diff if hardlink:
$ diff x/a y/a
Test mq hardlinking:
$ echo "[extensions]" >> $HGRCPATH
$ echo "mq=" >> $HGRCPATH
$ hg init a
$ cd a
$ hg qimport -n foo - << EOF
> # HG changeset patch
> # Date 1 0
> diff -r 2588a8b53d66 a
> --- /dev/null Thu Jan 01 00:00:00 1970 +0000
> +++ b/a Wed Jul 23 15:54:29 2008 +0200
> @@ -0,0 +1,1 @@
> +a
> EOF
adding foo to series file
$ hg qpush
applying foo
now at: foo
$ cd ..
$ linkcp a b
$ cd b
$ hg qimport -n bar - << EOF
> # HG changeset patch
> # Date 2 0
> diff -r 2588a8b53d66 a
> --- /dev/null Thu Jan 01 00:00:00 1970 +0000
> +++ b/b Wed Jul 23 15:54:29 2008 +0200
> @@ -0,0 +1,1 @@
> +b
> EOF
adding bar to series file
$ hg qpush
applying bar
now at: bar
$ cat .hg/patches/status
430ed4828a74fa4047bc816a25500f7472ab4bfe:foo
4e7abb4840c46a910f6d7b4d3c3fc7e5209e684c:bar
$ cat .hg/patches/series
foo
bar
$ cat ../a/.hg/patches/status
430ed4828a74fa4047bc816a25500f7472ab4bfe:foo
$ cat ../a/.hg/patches/series
foo
Test tags hardlinking:
$ hg qdel -r qbase:qtip
patch foo finalized without changeset message
patch bar finalized without changeset message
$ hg tag -l lfoo
$ hg tag foo
$ cd ..
$ linkcp b c
$ cd c
$ hg tag -l -r 0 lbar
$ hg tag -r 0 bar
$ cat .hgtags
4e7abb4840c46a910f6d7b4d3c3fc7e5209e684c foo
430ed4828a74fa4047bc816a25500f7472ab4bfe bar
$ cat .hg/localtags
4e7abb4840c46a910f6d7b4d3c3fc7e5209e684c lfoo
430ed4828a74fa4047bc816a25500f7472ab4bfe lbar
$ cat ../b/.hgtags
4e7abb4840c46a910f6d7b4d3c3fc7e5209e684c foo
$ cat ../b/.hg/localtags
4e7abb4840c46a910f6d7b4d3c3fc7e5209e684c lfoo
$ cd ..