Team,
while this mail talks about Git for Windows, please keep in mind that we
try *very* hard to keep Git for Windows' master working correctly not only
on Windows but also on macOS and Linux.
I, for one, run Git built from Git for Windows' `master` branch in my
Linux VMs all the time.
As all of you know by now, the fact that Git was pretty much designed to
work well on Linux is not exactly helping Git for Windows. (Or for that
matter, macOS: Git is substantially slower on macOS than on Linux when
running on the same hardware.) The quickest pay-off comes from converting
Unix shell scripts (which are designed to spawn processes, whereas Windows
is more optimized for multi-threaded applications).
For that reason, I was delighted to see that our Google Summer of Code
pushed pretty hard in that direction. And I could not help myself so I had
to test how much faster things got. Here is the result of my first, really
quick and dirty test:
without builtin stash/rebase with builtin stash/rebase
t3400 (rebase) 1m27s 32s
t3404 (rebase -i) 13m15s 3m59s
t3903 (stash) 8m37s 1m18s
What can I say? Even if the numbers are off by as much as 10%, these are
impressive improvements: keep in mind that there is a lot of churn going
on in the test suite because it is itself implemented in Unix shell
scripts (and hence I won't even bother to try more correct performance
benchmarking because that is simply not possible when Unix shell scripts
are in the equation). So the speed improvements of the stash/rebase
commands are *even higher* than this.
So I really, really, really want those builtins in Git for Windows
v2.19.0. At *least* as an option.
Therefore, after creating a pre-release of Git for Windows corresponding
to Git v2.19.0-rc0, I created another one (note the .2 at the end), *with*
those new builtins:
https://github.com/git-for-windows/git/releases/tag/v2.19.0-rc0.windows.2
I would like to ask you for help in dog-fooding this. In particular if you
are a heavy stash/rebase user (like I am), it would be helpful to really
kick those tires.
Of course, those are only Windows binaries on that web page, but it should
be easy to compile from that tag on Linux and macOS. I could also build a
macOS installer and add it to that pre-release, is there interest in that?
Currently I am uncertain whether I should spend the time to reinstate the
old scripted `git stash` guarded by `stash.useBuiltin` and the old
scripted `git rebase -i` (guarded by the same `rebase.useBuiltin` that
guards the scripted `git rebase`), as a fall-back (or make the new
builtins opt-ins instead of opt-outs).
So far, I have not encountered any serious bug, but then, I did not really
have a chance to use it yet (I installed it, of course, but I have not
done any serious rebasing yet). So your help will be crucial in
determining where I need to spend time.
Thanks,
Johannes
