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.
$ cat >> $HGRCPATH <<EOF
> [extensions]
> histedit=
> EOF
$ initrepos ()
> {
> hg init r
> cd r
> for x in a b c ; do
> echo $x > $x
> hg add $x
> hg ci -m $x
> done
> cd ..
> hg clone r r2 | grep -v updating
> cd r2
> for x in d e f ; do
> echo $x > $x
> hg add $x
> hg ci -m $x
> done
> cd ..
> hg init r3
> cd r3
> for x in g h i ; do
> echo $x > $x
> hg add $x
> hg ci -m $x
> done
> cd ..
> }
$ initrepos
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
show the edit commands offered by outgoing
$ cd r2
$ HGEDITOR=cat hg histedit --outgoing ../r | grep -v comparing | grep -v searching
pick 055a42cdd887 3 d
pick e860deea161a 4 e
pick 652413bf663e 5 f
# Edit history between 055a42cdd887 and 652413bf663e
#
# Commits are listed from least to most recent
#
# You can reorder changesets by reordering the lines
#
# Commands:
#
# e, edit = use commit, but stop for amending
# m, mess = edit commit message without changing commit content
# p, pick = use commit
# b, base = checkout changeset and apply further changesets from there
# d, drop = remove commit from history
# f, fold = use commit, but combine it with the one above
# r, roll = like fold, but discard this commit's description and date
#
$ cd ..
show the error from unrelated repos
$ cd r3
$ HGEDITOR=cat hg histedit --outgoing ../r | grep -v comparing | grep -v searching
abort: repository is unrelated
[1]
$ cd ..
show the error from unrelated repos
$ cd r3
$ HGEDITOR=cat hg histedit --force --outgoing ../r
comparing with ../r
searching for changes
warning: repository is unrelated
pick 2a4042b45417 0 g
pick 68c46b4927ce 1 h
pick 51281e65ba79 2 i
# Edit history between 2a4042b45417 and 51281e65ba79
#
# Commits are listed from least to most recent
#
# You can reorder changesets by reordering the lines
#
# Commands:
#
# e, edit = use commit, but stop for amending
# m, mess = edit commit message without changing commit content
# p, pick = use commit
# b, base = checkout changeset and apply further changesets from there
# d, drop = remove commit from history
# f, fold = use commit, but combine it with the one above
# r, roll = like fold, but discard this commit's description and date
#
$ cd ..
test sensitivity to branch in URL:
$ cd r2
$ hg -q update 2
$ hg -q branch foo
$ hg commit -m 'create foo branch'
$ HGEDITOR=cat hg histedit --outgoing '../r#foo' | grep -v comparing | grep -v searching
pick f26599ee3441 6 create foo branch
# Edit history between f26599ee3441 and f26599ee3441
#
# Commits are listed from least to most recent
#
# You can reorder changesets by reordering the lines
#
# Commands:
#
# e, edit = use commit, but stop for amending
# m, mess = edit commit message without changing commit content
# p, pick = use commit
# b, base = checkout changeset and apply further changesets from there
# d, drop = remove commit from history
# f, fold = use commit, but combine it with the one above
# r, roll = like fold, but discard this commit's description and date
#
test to check number of roots in outgoing revisions
$ hg -q outgoing -G --template '{node|short}({branch})' '../r'
@ f26599ee3441(foo)
o 652413bf663e(default)
|
o e860deea161a(default)
|
o 055a42cdd887(default)
$ HGEDITOR=cat hg -q histedit --outgoing '../r'
abort: there are ambiguous outgoing revisions
(see 'hg help histedit' for more detail)
[255]
$ hg -q update -C 2
$ echo aa >> a
$ hg -q commit -m 'another head on default'
$ hg -q outgoing -G --template '{node|short}({branch})' '../r#default'
@ 3879dc049647(default)
o 652413bf663e(default)
|
o e860deea161a(default)
|
o 055a42cdd887(default)
$ HGEDITOR=cat hg -q histedit --outgoing '../r#default'
abort: there are ambiguous outgoing revisions
(see 'hg help histedit' for more detail)
[255]
$ cd ..