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)
Create @ bookmark as main reference
$ hg init repo
$ cd repo
$ echo "[extensions]" >> $HGRCPATH
$ echo "patchbomb=" >> $HGRCPATH
$ hg book @
Create a dummy revision that must never be exported
$ echo no > no
$ hg ci -Amno -d '6 0'
adding no
Create a feature and use -B
$ hg book booktest
$ echo first > a
$ hg ci -Amfirst -d '7 0'
adding a
$ echo second > b
$ hg ci -Amsecond -d '8 0'
adding b
$ hg email --date '1981-1-1 0:1' -n -t foo -s bookmark -B booktest
From [test]: test
this patch series consists of 2 patches.
Write the introductory message for the patch series.
Cc:
displaying [PATCH 0 of 2] bookmark ...
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Subject: [PATCH 0 of 2] bookmark
Message-Id: <patchbomb.347155260@test-hostname>
User-Agent: Mercurial-patchbomb/* (glob)
Date: Thu, 01 Jan 1981 00:01:00 +0000
From: test
To: foo
displaying [PATCH 1 of 2] first ...
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Subject: [PATCH 1 of 2] first
X-Mercurial-Node: accde9b8b6dce861c185d0825c1affc09a79cb26
X-Mercurial-Series-Index: 1
X-Mercurial-Series-Total: 2
Message-Id: <accde9b8b6dce861c185.347155261@test-hostname>
X-Mercurial-Series-Id: <accde9b8b6dce861c185.347155261@test-hostname>
In-Reply-To: <patchbomb.347155260@test-hostname>
References: <patchbomb.347155260@test-hostname>
User-Agent: Mercurial-patchbomb/* (glob)
Date: Thu, 01 Jan 1981 00:01:01 +0000
From: test
To: foo
# HG changeset patch
# User test
# Date 7 0
# Thu Jan 01 00:00:07 1970 +0000
# Node ID accde9b8b6dce861c185d0825c1affc09a79cb26
# Parent 043bd3889e5aaf7d88fe3713cf425f782ad2fb71
first
diff -r 043bd3889e5a -r accde9b8b6dc a
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/a Thu Jan 01 00:00:07 1970 +0000
@@ -0,0 +1,1 @@
+first
displaying [PATCH 2 of 2] second ...
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Subject: [PATCH 2 of 2] second
X-Mercurial-Node: 417defd1559c396ba06a44dce8dc1c2d2d653f3f
X-Mercurial-Series-Index: 2
X-Mercurial-Series-Total: 2
Message-Id: <417defd1559c396ba06a.347155262@test-hostname>
X-Mercurial-Series-Id: <accde9b8b6dce861c185.347155261@test-hostname>
In-Reply-To: <patchbomb.347155260@test-hostname>
References: <patchbomb.347155260@test-hostname>
User-Agent: Mercurial-patchbomb/* (glob)
Date: Thu, 01 Jan 1981 00:01:02 +0000
From: test
To: foo
# HG changeset patch
# User test
# Date 8 0
# Thu Jan 01 00:00:08 1970 +0000
# Node ID 417defd1559c396ba06a44dce8dc1c2d2d653f3f
# Parent accde9b8b6dce861c185d0825c1affc09a79cb26
second
diff -r accde9b8b6dc -r 417defd1559c b
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/b Thu Jan 01 00:00:08 1970 +0000
@@ -0,0 +1,1 @@
+second
Do the same and combine with -o only one must be exported
$ cd ..
$ hg clone repo repo2
updating to bookmark @
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd repo
$ hg up @
0 files updated, 0 files merged, 2 files removed, 0 files unresolved
(activating bookmark @)
$ hg book outgoing
$ echo 1 > x
$ hg ci -Am1 -d '8 0'
adding x
created new head
$ hg push ../repo2 -B outgoing
pushing to ../repo2
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
exporting bookmark outgoing
$ echo 2 > y
$ hg ci -Am2 -d '9 0'
adding y
$ hg email --date '1982-1-1 0:1' -n -t foo -s bookmark -B outgoing -o ../repo2
comparing with ../repo2
From [test]: test
this patch series consists of 1 patches.
Cc:
displaying [PATCH] bookmark ...
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Subject: [PATCH] bookmark
X-Mercurial-Node: 8dab2639fd35f1e337ad866c372a5c44f1064e3c
X-Mercurial-Series-Index: 1
X-Mercurial-Series-Total: 1
Message-Id: <8dab2639fd35f1e337ad.378691260@test-hostname>
X-Mercurial-Series-Id: <8dab2639fd35f1e337ad.378691260@test-hostname>
User-Agent: Mercurial-patchbomb/* (glob)
Date: Fri, 01 Jan 1982 00:01:00 +0000
From: test
To: foo
# HG changeset patch
# User test
# Date 9 0
# Thu Jan 01 00:00:09 1970 +0000
# Node ID 8dab2639fd35f1e337ad866c372a5c44f1064e3c
# Parent 0b24b8316483bf30bfc3e4d4168e922b169dbe66
2
diff -r 0b24b8316483 -r 8dab2639fd35 y
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/y Thu Jan 01 00:00:09 1970 +0000
@@ -0,0 +1,1 @@
+2