perf: add threading capability to perfbdiff
Since we are releasing the GIL during diffing, it is interesting to see how a
thread pool would perform on diffing. We add a new `--threads` argument to
commands. Synchronizing the thread pool is a bit complex because we want to be
able to reuse it from one run to another.
On my computer (i7 with 4 cores + hyperthreading), I get the following data for
about 12000 revisions:
threads wall comb wall gain comb overhead
none 31.596715 31.59 0.00% 0.00%
1 31.621228 31.62 -0.08% 0.09%
2 16.406202 32.8 48.08% 3.83%
3 11.598334 34.76 63.29% 10.03%
4 9.205421 36.77 70.87% 16.40%
5 8.517604 42.51 73.04% 34.57%
6 7.94645 47.58 74.85% 50.62%
7 7.434972 51.92 76.47% 64.36%
8 7.070638 55.34 77.62% 75.18%
Compared to the feature disabled (threads=0), the overhead is negligible with
the threading code (threads=1), and the gain is already 48% with two threads.
Issue746: renaming files brought by the second parent of a merge was
broken.
Create source repository:
$ hg init t
$ cd t
$ echo a > a
$ hg ci -Am a
adding a
$ cd ..
Fork source repository:
$ hg clone t t2
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd t2
$ echo b > b
$ hg ci -Am b
adding b
Update source repository:
$ cd ../t
$ echo a >> a
$ hg ci -m a2
Merge repositories:
$ hg pull ../t2
pulling from ../t2
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
new changesets d2ae7f538514
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg merge
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg st
M b
Rename b as c:
$ hg mv b c
$ hg st
A c
R b
Rename back c as b:
$ hg mv c b
$ hg st
M b
$ cd ..
Issue 1476: renaming a first parent file into another first parent
file while none of them belong to the second parent was broken
$ hg init repo1476
$ cd repo1476
$ echo a > a
$ hg ci -Am adda
adding a
$ echo b1 > b1
$ echo b2 > b2
$ hg ci -Am changea
adding b1
adding b2
$ hg up -C 0
0 files updated, 0 files merged, 2 files removed, 0 files unresolved
$ echo c1 > c1
$ echo c2 > c2
$ hg ci -Am addcandd
adding c1
adding c2
created new head
Merge heads:
$ hg merge
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg mv -Af c1 c2
Commit issue 1476:
$ hg ci -m merge
$ hg log -r tip -C -v | grep copies
copies: c2 (c1)
$ hg rollback
repository tip rolled back to revision 2 (undo commit)
working directory now based on revisions 2 and 1
$ hg up -C .
2 files updated, 0 files merged, 2 files removed, 0 files unresolved
Merge heads again:
$ hg merge
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg mv -Af b1 b2
Commit issue 1476 with a rename on the other side:
$ hg ci -m merge
$ hg log -r tip -C -v | grep copies
copies: b2 (b1)
$ cd ..