Mercurial > hg
view tests/test-bundle-r.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 | d0abd7949ea3 |
children | 89630d0b3e23 |
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$ hg init test $ cd test $ hg unbundle "$TESTDIR/bundles/remote.hg" adding changesets adding manifests adding file changes added 9 changesets with 7 changes to 4 files (+1 heads) new changesets bfaf4b5cbf01:916f1afdef90 (run 'hg heads' to see heads, 'hg merge' to merge) $ hg up tip 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ cd .. $ for i in 0 1 2 3 4 5 6 7 8; do > mkdir test-"$i" > hg --cwd test-"$i" init > hg -R test bundle -r "$i" test-"$i".hg test-"$i" > cd test-"$i" > hg unbundle ../test-"$i".hg > hg verify > hg tip -q > cd .. > done searching for changes 1 changesets found adding changesets adding manifests adding file changes added 1 changesets with 1 changes to 1 files new changesets bfaf4b5cbf01 (run 'hg update' to get a working copy) checking changesets checking manifests crosschecking files in changesets and manifests checking files 1 files, 1 changesets, 1 total revisions 0:bfaf4b5cbf01 searching for changes 2 changesets found adding changesets adding manifests adding file changes added 2 changesets with 2 changes to 1 files new changesets bfaf4b5cbf01:21f32785131f (run 'hg update' to get a working copy) checking changesets checking manifests crosschecking files in changesets and manifests checking files 1 files, 2 changesets, 2 total revisions 1:21f32785131f searching for changes 3 changesets found adding changesets adding manifests adding file changes added 3 changesets with 3 changes to 1 files new changesets bfaf4b5cbf01:4ce51a113780 (run 'hg update' to get a working copy) checking changesets checking manifests crosschecking files in changesets and manifests checking files 1 files, 3 changesets, 3 total revisions 2:4ce51a113780 searching for changes 4 changesets found adding changesets adding manifests adding file changes added 4 changesets with 4 changes to 1 files new changesets bfaf4b5cbf01:93ee6ab32777 (run 'hg update' to get a working copy) checking changesets checking manifests crosschecking files in changesets and manifests checking files 1 files, 4 changesets, 4 total revisions 3:93ee6ab32777 searching for changes 2 changesets found adding changesets adding manifests adding file changes added 2 changesets with 2 changes to 1 files new changesets bfaf4b5cbf01:c70afb1ee985 (run 'hg update' to get a working copy) checking changesets checking manifests crosschecking files in changesets and manifests checking files 1 files, 2 changesets, 2 total revisions 1:c70afb1ee985 searching for changes 3 changesets found adding changesets adding manifests adding file changes added 3 changesets with 3 changes to 1 files new changesets bfaf4b5cbf01:f03ae5a9b979 (run 'hg update' to get a working copy) checking changesets checking manifests crosschecking files in changesets and manifests checking files 1 files, 3 changesets, 3 total revisions 2:f03ae5a9b979 searching for changes 4 changesets found adding changesets adding manifests adding file changes added 4 changesets with 5 changes to 2 files new changesets bfaf4b5cbf01:095cb14b1b4d (run 'hg update' to get a working copy) checking changesets checking manifests crosschecking files in changesets and manifests checking files 2 files, 4 changesets, 5 total revisions 3:095cb14b1b4d searching for changes 5 changesets found adding changesets adding manifests adding file changes added 5 changesets with 6 changes to 3 files new changesets bfaf4b5cbf01:faa2e4234c7a (run 'hg update' to get a working copy) checking changesets checking manifests crosschecking files in changesets and manifests checking files 3 files, 5 changesets, 6 total revisions 4:faa2e4234c7a searching for changes 5 changesets found adding changesets adding manifests adding file changes added 5 changesets with 5 changes to 2 files new changesets bfaf4b5cbf01:916f1afdef90 (run 'hg update' to get a working copy) checking changesets checking manifests crosschecking files in changesets and manifests checking files 2 files, 5 changesets, 5 total revisions 4:916f1afdef90 $ cd test-8 $ hg pull ../test-7 pulling from ../test-7 searching for changes adding changesets adding manifests adding file changes added 4 changesets with 2 changes to 3 files (+1 heads) new changesets c70afb1ee985:faa2e4234c7a 1 local changesets published (run 'hg heads' to see heads, 'hg merge' to merge) $ hg verify checking changesets checking manifests crosschecking files in changesets and manifests checking files 4 files, 9 changesets, 7 total revisions $ hg rollback repository tip rolled back to revision 4 (undo pull) $ cd .. should fail $ hg -R test bundle --base 2 -r tip test-bundle-branch1.hg test-3 abort: --base is incompatible with specifying a destination [255] $ hg -R test bundle -a -r tip test-bundle-branch1.hg test-3 abort: --all is incompatible with specifying a destination [255] $ hg -R test bundle -r tip test-bundle-branch1.hg abort: repository default-push not found! [255] $ hg -R test bundle --base 2 -r tip test-bundle-branch1.hg 2 changesets found $ hg -R test bundle --base 2 -r 7 test-bundle-branch2.hg 4 changesets found $ hg -R test bundle --base 2 test-bundle-all.hg 6 changesets found $ hg -R test bundle --base 2 --all test-bundle-all-2.hg ignoring --base because --all was specified 9 changesets found $ hg -R test bundle --base 3 -r tip test-bundle-should-fail.hg 1 changesets found empty bundle $ hg -R test bundle --base 7 --base 8 test-bundle-empty.hg no changes found [1] issue76 msg2163 $ hg -R test bundle --base 3 -r 3 -r 3 test-bundle-cset-3.hg no changes found [1] Issue1910: 'hg bundle --base $head' does not exclude $head from result $ hg -R test bundle --base 7 test-bundle-cset-7.hg 4 changesets found $ hg clone test-2 test-9 updating to branch default 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ cd test-9 revision 2 $ hg tip -q 2:4ce51a113780 $ hg unbundle ../test-bundle-should-fail.hg adding changesets transaction abort! rollback completed abort: 00changelog.i@93ee6ab32777: unknown parent! [255] revision 2 $ hg tip -q 2:4ce51a113780 $ hg unbundle ../test-bundle-all.hg adding changesets adding manifests adding file changes added 6 changesets with 4 changes to 4 files (+1 heads) new changesets 93ee6ab32777:916f1afdef90 (run 'hg heads' to see heads, 'hg merge' to merge) revision 8 $ hg tip -q 8:916f1afdef90 $ hg verify checking changesets checking manifests crosschecking files in changesets and manifests checking files 4 files, 9 changesets, 7 total revisions $ hg rollback repository tip rolled back to revision 2 (undo unbundle) revision 2 $ hg tip -q 2:4ce51a113780 $ hg unbundle ../test-bundle-branch1.hg adding changesets adding manifests adding file changes added 2 changesets with 2 changes to 2 files new changesets 93ee6ab32777:916f1afdef90 (run 'hg update' to get a working copy) revision 4 $ hg tip -q 4:916f1afdef90 $ hg verify checking changesets checking manifests crosschecking files in changesets and manifests checking files 2 files, 5 changesets, 5 total revisions $ hg rollback repository tip rolled back to revision 2 (undo unbundle) $ hg unbundle ../test-bundle-branch2.hg adding changesets adding manifests adding file changes added 4 changesets with 3 changes to 3 files (+1 heads) new changesets c70afb1ee985:faa2e4234c7a (run 'hg heads' to see heads, 'hg merge' to merge) revision 6 $ hg tip -q 6:faa2e4234c7a $ hg verify checking changesets checking manifests crosschecking files in changesets and manifests checking files 3 files, 7 changesets, 6 total revisions $ hg rollback repository tip rolled back to revision 2 (undo unbundle) $ hg unbundle ../test-bundle-cset-7.hg adding changesets adding manifests adding file changes added 2 changesets with 2 changes to 2 files new changesets 93ee6ab32777:916f1afdef90 (run 'hg update' to get a working copy) revision 4 $ hg tip -q 4:916f1afdef90 $ hg verify checking changesets checking manifests crosschecking files in changesets and manifests checking files 2 files, 5 changesets, 5 total revisions $ cd ../test $ hg merge 7 note: possible conflict - afile was renamed multiple times to: anotherfile adifferentfile 2 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg ci -m merge $ cd .. $ hg -R test bundle --base 2 test-bundle-head.hg 7 changesets found $ hg clone test-2 test-10 updating to branch default 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ cd test-10 $ hg unbundle ../test-bundle-head.hg adding changesets adding manifests adding file changes added 7 changesets with 4 changes to 4 files new changesets 93ee6ab32777:03fc0b0e347c (run 'hg update' to get a working copy) revision 9 $ hg tip -q 9:03fc0b0e347c $ hg verify checking changesets checking manifests crosschecking files in changesets and manifests checking files 4 files, 10 changesets, 7 total revisions $ cd ..