Mercurial > hg
view tests/test-merge1.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 | 2a774cae3a03 |
children | 8c6775e812d8 |
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$ cat <<EOF > merge > from __future__ import print_function > import sys, os > > try: > import msvcrt > msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY) > msvcrt.setmode(sys.stderr.fileno(), os.O_BINARY) > except ImportError: > pass > > print("merging for", os.path.basename(sys.argv[1])) > EOF $ HGMERGE="$PYTHON ../merge"; export HGMERGE $ hg init t $ cd t $ echo This is file a1 > a $ hg add a $ hg commit -m "commit #0" $ echo This is file b1 > b $ hg add b $ hg commit -m "commit #1" $ hg update 0 0 files updated, 0 files merged, 1 files removed, 0 files unresolved Test interrupted updates by having a non-empty dir with the same name as one of the files in a commit we're updating to $ mkdir b && touch b/nonempty $ hg up 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg ci nothing changed [1] $ hg sum parent: 1:b8bb4a988f25 tip commit #1 branch: default commit: (clean) update: (current) phases: 2 draft The following line is commented out because the file doesn't exist at the moment, and some OSes error out even with `rm -f`. $ rm b/nonempty $ hg up 0 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg sum parent: 1:b8bb4a988f25 tip commit #1 branch: default commit: (clean) update: (current) phases: 2 draft Prepare a basic merge $ hg up 0 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ echo This is file c1 > c $ hg add c $ hg commit -m "commit #2" created new head $ echo This is file b1 > b no merges expected $ hg merge -P 1 changeset: 1:b8bb4a988f25 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: commit #1 $ hg merge 1 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg diff --nodates diff -r 49035e18a8e6 b --- /dev/null +++ b/b @@ -0,0 +1,1 @@ +This is file b1 $ hg status M b $ cd ..; rm -r t $ hg init t $ cd t $ echo This is file a1 > a $ hg add a $ hg commit -m "commit #0" $ echo This is file b1 > b $ hg add b $ hg commit -m "commit #1" $ hg update 0 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ echo This is file c1 > c $ hg add c $ hg commit -m "commit #2" created new head $ echo This is file b2 > b merge should fail $ hg merge 1 b: untracked file differs abort: untracked files in working directory differ from files in requested revision [255] #if symlink symlinks to directories should be treated as regular files (issue5027) $ rm b $ ln -s 'This is file b2' b $ hg merge 1 b: untracked file differs abort: untracked files in working directory differ from files in requested revision [255] symlinks shouldn't be followed $ rm b $ echo This is file b1 > .hg/b $ ln -s .hg/b b $ hg merge 1 b: untracked file differs abort: untracked files in working directory differ from files in requested revision [255] $ rm b $ echo This is file b2 > b #endif bad config $ hg merge 1 --config merge.checkunknown=x abort: merge.checkunknown not valid ('x' is none of 'abort', 'ignore', 'warn') [255] this merge should fail $ hg merge 1 --config merge.checkunknown=abort b: untracked file differs abort: untracked files in working directory differ from files in requested revision [255] this merge should warn $ hg merge 1 --config merge.checkunknown=warn b: replacing untracked file 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cat b.orig This is file b2 $ hg up --clean 2 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ mv b.orig b this merge should silently ignore $ cat b This is file b2 $ hg merge 1 --config merge.checkunknown=ignore 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) merge.checkignored $ hg up --clean 1 1 files updated, 0 files merged, 1 files removed, 0 files unresolved $ cat >> .hgignore << EOF > remoteignored > EOF $ echo This is file localignored3 > localignored $ echo This is file remoteignored3 > remoteignored $ hg add .hgignore localignored remoteignored $ hg commit -m "commit #3" $ hg up 2 1 files updated, 0 files merged, 4 files removed, 0 files unresolved $ cat >> .hgignore << EOF > localignored > EOF $ hg add .hgignore $ hg commit -m "commit #4" remote .hgignore shouldn't be used for determining whether a file is ignored $ echo This is file remoteignored4 > remoteignored $ hg merge 3 --config merge.checkignored=ignore --config merge.checkunknown=abort remoteignored: untracked file differs abort: untracked files in working directory differ from files in requested revision [255] $ hg merge 3 --config merge.checkignored=abort --config merge.checkunknown=ignore merging .hgignore merging for .hgignore 3 files updated, 1 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cat remoteignored This is file remoteignored3 $ cat remoteignored.orig This is file remoteignored4 $ rm remoteignored.orig local .hgignore should be used for that $ hg up --clean 4 1 files updated, 0 files merged, 3 files removed, 0 files unresolved $ echo This is file localignored4 > localignored also test other conflicting files to see we output the full set of warnings $ echo This is file b2 > b $ hg merge 3 --config merge.checkignored=abort --config merge.checkunknown=abort b: untracked file differs localignored: untracked file differs abort: untracked files in working directory differ from files in requested revision [255] $ hg merge 3 --config merge.checkignored=abort --config merge.checkunknown=ignore localignored: untracked file differs abort: untracked files in working directory differ from files in requested revision [255] $ hg merge 3 --config merge.checkignored=warn --config merge.checkunknown=abort b: untracked file differs abort: untracked files in working directory differ from files in requested revision [255] $ hg merge 3 --config merge.checkignored=warn --config merge.checkunknown=warn b: replacing untracked file localignored: replacing untracked file merging .hgignore merging for .hgignore 3 files updated, 1 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cat localignored This is file localignored3 $ cat localignored.orig This is file localignored4 $ rm localignored.orig $ cat b.orig This is file b2 $ hg up --clean 2 0 files updated, 0 files merged, 4 files removed, 0 files unresolved $ mv b.orig b this merge of b should work $ cat b This is file b2 $ hg merge -f 1 merging b merging for b 0 files updated, 1 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg diff --nodates diff -r 49035e18a8e6 b --- /dev/null +++ b/b @@ -0,0 +1,1 @@ +This is file b2 $ hg status M b $ cd ..; rm -r t $ hg init t $ cd t $ echo This is file a1 > a $ hg add a $ hg commit -m "commit #0" $ echo This is file b1 > b $ hg add b $ hg commit -m "commit #1" $ echo This is file b22 > b $ hg commit -m "commit #2" $ hg update 1 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ echo This is file c1 > c $ hg add c $ hg commit -m "commit #3" created new head Contents of b should be "this is file b1" $ cat b This is file b1 $ echo This is file b22 > b merge fails $ hg merge 2 abort: uncommitted changes (use 'hg status' to list changes) [255] merge expected! $ hg merge -f 2 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg diff --nodates diff -r 85de557015a8 b --- a/b +++ b/b @@ -1,1 +1,1 @@ -This is file b1 +This is file b22 $ hg status M b $ cd ..; rm -r t $ hg init t $ cd t $ echo This is file a1 > a $ hg add a $ hg commit -m "commit #0" $ echo This is file b1 > b $ hg add b $ hg commit -m "commit #1" $ echo This is file b22 > b $ hg commit -m "commit #2" $ hg update 1 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ echo This is file c1 > c $ hg add c $ hg commit -m "commit #3" created new head $ echo This is file b33 > b merge of b should fail $ hg merge 2 abort: uncommitted changes (use 'hg status' to list changes) [255] merge of b expected $ hg merge -f 2 merging b merging for b 0 files updated, 1 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg diff --nodates diff -r 85de557015a8 b --- a/b +++ b/b @@ -1,1 +1,1 @@ -This is file b1 +This is file b33 $ hg status M b Test for issue2364 $ hg up -qC . $ hg rm b $ hg ci -md $ hg revert -r -2 b $ hg up -q -- -2 Test that updated files are treated as "modified", when 'merge.update()' is aborted before 'merge.recordupdates()' (= parents aren't changed), even if none of mode, size and timestamp of them isn't changed on the filesystem (see also issue4583). $ cat > $TESTTMP/abort.py <<EOF > from __future__ import absolute_import > # emulate aborting before "recordupdates()". in this case, files > # are changed without updating dirstate > from mercurial import ( > error, > extensions, > merge, > ) > def applyupdates(orig, *args, **kwargs): > orig(*args, **kwargs) > raise error.Abort('intentional aborting') > def extsetup(ui): > extensions.wrapfunction(merge, "applyupdates", applyupdates) > EOF $ cat >> .hg/hgrc <<EOF > [fakedirstatewritetime] > # emulate invoking dirstate.write() via repo.status() > # at 2000-01-01 00:00 > fakenow = 200001010000 > EOF (file gotten from other revision) $ hg update -q -C 2 $ echo 'THIS IS FILE B5' > b $ hg commit -m 'commit #5' $ hg update -q -C 3 $ cat b This is file b1 $ touch -t 200001010000 b $ hg debugrebuildstate $ cat >> .hg/hgrc <<EOF > [extensions] > fakedirstatewritetime = $TESTDIR/fakedirstatewritetime.py > abort = $TESTTMP/abort.py > EOF $ hg merge 5 abort: intentional aborting [255] $ cat >> .hg/hgrc <<EOF > [extensions] > fakedirstatewritetime = ! > abort = ! > EOF $ cat b THIS IS FILE B5 $ touch -t 200001010000 b $ hg status -A b M b (file merged from other revision) $ hg update -q -C 3 $ echo 'this is file b6' > b $ hg commit -m 'commit #6' created new head $ cat b this is file b6 $ touch -t 200001010000 b $ hg debugrebuildstate $ cat >> .hg/hgrc <<EOF > [extensions] > fakedirstatewritetime = $TESTDIR/fakedirstatewritetime.py > abort = $TESTTMP/abort.py > EOF $ hg merge --tool internal:other 5 abort: intentional aborting [255] $ cat >> .hg/hgrc <<EOF > [extensions] > fakedirstatewritetime = ! > abort = ! > EOF $ cat b THIS IS FILE B5 $ touch -t 200001010000 b $ hg status -A b M b $ cd ..