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view tests/test-journal.t @ 38732:be4984261611
merge: mark file gets as not thread safe (issue5933)
In default installs, this has the effect of disabling the thread-based
worker on Windows when manifesting files in the working directory. My
measurements have shown that with revlog-based repositories, Mercurial
spends a lot of CPU time in revlog code resolving file data. This ends
up incurring a lot of context switching across threads and slows down
`hg update` operations when going from an empty working directory to
the tip of the repo.
On mozilla-unified (246,351 files) on an i7-6700K (4+4 CPUs):
before: 487s wall
after: 360s wall (equivalent to worker.enabled=false)
cpus=2: 379s wall
Even with only 2 threads, the thread pool is still slower.
The introduction of the thread-based worker (02b36e860e0b) states that
it resulted in a "~50%" speedup for `hg sparse --enable-profile` and
`hg sparse --disable-profile`. This disagrees with my measurement
above. I theorize a few reasons for this:
1) Removal of files from the working directory is I/O - not CPU - bound
and should benefit from a thread pool (unless I/O is insanely fast
and the GIL release is near instantaneous). So tests like `hg sparse
--enable-profile` may exercise deletion throughput and aren't good
benchmarks for worker tasks that are CPU heavy.
2) The patch was authored by someone at Facebook. The results were
likely measured against a repository using remotefilelog. And I
believe that revision retrieval during working directory updates with
remotefilelog will often use a remote store, thus being I/O and not
CPU bound. This probably resulted in an overstated performance gain.
Since there appears to be a need to enable the thread-based worker with
some stores, I've made the flagging of file gets as thread safe
configurable. I've made it experimental because I don't want to formalize
a boolean flag for this option and because this attribute is best
captured against the store implementation. But we don't have a proper
store API for this yet. I'd rather cross this bridge later.
It is possible there are revlog-based repositories that do benefit from
a thread-based worker. I didn't do very comprehensive testing. If there
are, we may want to devise a more proper algorithm for whether to use
the thread-based worker, including possibly config options to limit the
number of threads to use. But until I see evidence that justifies
complexity, simplicity wins.
Differential Revision: https://phab.mercurial-scm.org/D3963
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Wed, 18 Jul 2018 09:49:34 -0700 |
parents | 31750413f8d7 |
children | dea771e63c3c |
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Tests for the journal extension; records bookmark locations. $ cat >> testmocks.py << EOF > # mock out procutil.getuser() and util.makedate() to supply testable values > import os > from mercurial import util, pycompat > from mercurial.utils import dateutil, procutil > def mockgetuser(): > return b'foobar' > > def mockmakedate(): > filename = os.path.join(os.environ['TESTTMP'], 'testtime') > try: > with open(filename, 'rb') as timef: > time = float(timef.read()) + 1 > except IOError: > time = 0.0 > with open(filename, 'wb') as timef: > timef.write(pycompat.bytestr(time)) > return (time, 0) > > procutil.getuser = mockgetuser > dateutil.makedate = mockmakedate > EOF $ cat >> $HGRCPATH << EOF > [extensions] > journal= > testmocks=`pwd`/testmocks.py > EOF Setup repo $ hg init repo $ cd repo Test empty journal $ hg journal previous locations of '.': no recorded locations $ hg journal foo previous locations of 'foo': no recorded locations Test that working copy changes are tracked $ echo a > a $ hg commit -Aqm a $ hg journal previous locations of '.': cb9a9f314b8b commit -Aqm a $ echo b > a $ hg commit -Aqm b $ hg journal previous locations of '.': 1e6c11564562 commit -Aqm b cb9a9f314b8b commit -Aqm a $ hg up 0 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg journal previous locations of '.': cb9a9f314b8b up 0 1e6c11564562 commit -Aqm b cb9a9f314b8b commit -Aqm a Test that bookmarks are tracked $ hg book -r tip bar $ hg journal bar previous locations of 'bar': 1e6c11564562 book -r tip bar $ hg book -f bar $ hg journal bar previous locations of 'bar': cb9a9f314b8b book -f bar 1e6c11564562 book -r tip bar $ hg up 1 files updated, 0 files merged, 0 files removed, 0 files unresolved updating bookmark bar $ hg journal bar previous locations of 'bar': 1e6c11564562 up cb9a9f314b8b book -f bar 1e6c11564562 book -r tip bar Test that bookmarks and working copy tracking is not mixed $ hg journal previous locations of '.': 1e6c11564562 up cb9a9f314b8b up 0 1e6c11564562 commit -Aqm b cb9a9f314b8b commit -Aqm a Test that you can list all entries as well as limit the list or filter on them $ hg book -r tip baz $ hg journal --all previous locations of the working copy and bookmarks: 1e6c11564562 baz book -r tip baz 1e6c11564562 bar up 1e6c11564562 . up cb9a9f314b8b bar book -f bar 1e6c11564562 bar book -r tip bar cb9a9f314b8b . up 0 1e6c11564562 . commit -Aqm b cb9a9f314b8b . commit -Aqm a $ hg journal --limit 2 previous locations of '.': 1e6c11564562 up cb9a9f314b8b up 0 $ hg journal bar previous locations of 'bar': 1e6c11564562 up cb9a9f314b8b book -f bar 1e6c11564562 book -r tip bar $ hg journal foo previous locations of 'foo': no recorded locations $ hg journal . previous locations of '.': 1e6c11564562 up cb9a9f314b8b up 0 1e6c11564562 commit -Aqm b cb9a9f314b8b commit -Aqm a $ hg journal "re:ba." previous locations of 're:ba.': 1e6c11564562 baz book -r tip baz 1e6c11564562 bar up cb9a9f314b8b bar book -f bar 1e6c11564562 bar book -r tip bar Test that verbose, JSON, template and commit output work $ hg journal --verbose --all previous locations of the working copy and bookmarks: 000000000000 -> 1e6c11564562 foobar baz 1970-01-01 00:00 +0000 book -r tip baz cb9a9f314b8b -> 1e6c11564562 foobar bar 1970-01-01 00:00 +0000 up cb9a9f314b8b -> 1e6c11564562 foobar . 1970-01-01 00:00 +0000 up 1e6c11564562 -> cb9a9f314b8b foobar bar 1970-01-01 00:00 +0000 book -f bar 000000000000 -> 1e6c11564562 foobar bar 1970-01-01 00:00 +0000 book -r tip bar 1e6c11564562 -> cb9a9f314b8b foobar . 1970-01-01 00:00 +0000 up 0 cb9a9f314b8b -> 1e6c11564562 foobar . 1970-01-01 00:00 +0000 commit -Aqm b 000000000000 -> cb9a9f314b8b foobar . 1970-01-01 00:00 +0000 commit -Aqm a $ hg journal --verbose -Tjson [ { "command": "up", "date": [5, 0], "name": ".", "newhashes": ["1e6c11564562b4ed919baca798bc4338bd299d6a"], "oldhashes": ["cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b"], "user": "foobar" }, { "command": "up 0", "date": [2, 0], "name": ".", "newhashes": ["cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b"], "oldhashes": ["1e6c11564562b4ed919baca798bc4338bd299d6a"], "user": "foobar" }, { "command": "commit -Aqm b", "date": [1, 0], "name": ".", "newhashes": ["1e6c11564562b4ed919baca798bc4338bd299d6a"], "oldhashes": ["cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b"], "user": "foobar" }, { "command": "commit -Aqm a", "date": [0, 0], "name": ".", "newhashes": ["cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b"], "oldhashes": ["0000000000000000000000000000000000000000"], "user": "foobar" } ] $ cat <<EOF >> $HGRCPATH > [templates] > j = "{oldhashes % '{node|upper}'} -> {newhashes % '{node|upper}'} > - user: {user} > - command: {command} > - date: {date|rfc3339date} > - newhashes: {newhashes} > - oldhashes: {oldhashes} > " > EOF $ hg journal -Tj -l1 previous locations of '.': CB9A9F314B8B07BA71012FCDBC544B5A4D82FF5B -> 1E6C11564562B4ED919BACA798BC4338BD299D6A - user: foobar - command: up - date: 1970-01-01T00:00:05+00:00 - newhashes: 1e6c11564562b4ed919baca798bc4338bd299d6a - oldhashes: cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b $ hg journal --commit previous locations of '.': 1e6c11564562 up changeset: 1:1e6c11564562 bookmark: bar bookmark: baz tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: b cb9a9f314b8b up 0 changeset: 0:cb9a9f314b8b user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: a 1e6c11564562 commit -Aqm b changeset: 1:1e6c11564562 bookmark: bar bookmark: baz tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: b cb9a9f314b8b commit -Aqm a changeset: 0:cb9a9f314b8b user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: a Test for behaviour on unexpected storage version information $ printf '42\0' > .hg/namejournal $ hg journal previous locations of '.': abort: unknown journal file version '42' [255] $ hg book -r tip doomed unsupported journal file version '42'