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
ATTENTION: logtoprocess runs commands asynchronously. Be sure to append "| cat"
to hg commands, to wait for the output, if you want to test its output.
Otherwise the test will be flaky.
Test if logtoprocess correctly captures command-related log calls.
$ hg init
$ cat > $TESTTMP/foocommand.py << EOF
> from mercurial import registrar
> cmdtable = {}
> command = registrar.command(cmdtable)
> configtable = {}
> configitem = registrar.configitem(configtable)
> configitem(b'logtoprocess', b'foo',
> default=None,
> )
> @command(b'foobar', [])
> def foo(ui, repo):
> ui.log(b'foo', b'a message: %s\n', b'spam')
> EOF
$ cp $HGRCPATH $HGRCPATH.bak
$ cat >> $HGRCPATH << EOF
> [extensions]
> logtoprocess=
> foocommand=$TESTTMP/foocommand.py
> [logtoprocess]
> command=(echo 'logtoprocess command output:';
> echo "\$EVENT";
> echo "\$MSG1") > $TESTTMP/command.log
> commandfinish=(echo 'logtoprocess commandfinish output:';
> echo "\$EVENT";
> echo "\$MSG1";
> echo "canonical: \$OPT_CANONICAL_COMMAND") > $TESTTMP/commandfinish.log
> foo=(echo 'logtoprocess foo output:';
> echo "\$EVENT";
> echo "\$MSG1") > $TESTTMP/foo.log
> EOF
Running a command triggers both a ui.log('command') and a
ui.log('commandfinish') call. The foo command also uses ui.log.
Use sort to avoid ordering issues between the various processes we spawn:
$ hg fooba
$ sleep 1
$ cat $TESTTMP/command.log | sort
command
fooba
logtoprocess command output:
#if no-chg
$ cat $TESTTMP/commandfinish.log | sort
canonical: foobar
commandfinish
fooba exited 0 after * seconds (glob)
logtoprocess commandfinish output:
$ cat $TESTTMP/foo.log | sort
a message: spam
foo
logtoprocess foo output:
#endif
Confirm that logging blocked time catches stdio properly:
$ cp $HGRCPATH.bak $HGRCPATH
$ cat >> $HGRCPATH << EOF
> [extensions]
> logtoprocess=
> pager=
> [logtoprocess]
> uiblocked=echo "\$EVENT stdio \$OPT_STDIO_BLOCKED ms command \$OPT_COMMAND_DURATION ms" > $TESTTMP/uiblocked.log
> [ui]
> logblockedtimes=True
> EOF
$ hg log
$ sleep 1
$ cat $TESTTMP/uiblocked.log
uiblocked stdio [0-9]+.[0-9]* ms command [0-9]+.[0-9]* ms (re)
Try to confirm that pager wait on logtoprocess:
Add a script that waits on a file to appear. If the script is awaited by hg,
the script will die after the timeout before we could touch the file and the
resulting file will not exist. If not, we will touch the file and see it.
$ cat >> fakepager.py <<EOF
> import sys
> printed = False
> for line in sys.stdin:
> sys.stdout.write(line)
> printed = True
> if not printed:
> sys.stdout.write('paged empty output!\n')
> EOF
$ cat > $TESTTMP/wait-output.sh << EOF
> #!/bin/sh
> set -eu
> "$RUNTESTDIR/testlib/wait-on-file" 10 "$TESTTMP/wait-for-touched"
> touch "$TESTTMP/touched"
> EOF
$ chmod +x $TESTTMP/wait-output.sh
$ cat >> $HGRCPATH << EOF
> [extensions]
> logtoprocess=
> pager=
> [pager]
> pager = "$PYTHON" $TESTTMP/fakepager.py
> [logtoprocess]
> commandfinish=$TESTTMP/wait-output.sh
> EOF
$ hg version -q --pager=always
Mercurial Distributed SCM (version *) (glob)
$ touch $TESTTMP/wait-for-touched
$ "$RUNTESTDIR/testlib/wait-on-file" 5 "$TESTTMP/touched"
$ test -f $TESTTMP/touched && echo "SUCCESS Pager is not waiting on ltp" || echo "FAIL Pager is waiting on ltp"
SUCCESS Pager is not waiting on ltp