Re: Debugging git-commit slowness on a large repo

Joshua Redstone [off-list ref] writes:

I've managed to speed up git-commit on large repos by 4x by removing some
safeguards that caused git to stat every file in the repo on commits that
touch a small number of files.  The diff, for illustrative purposes only,
is at:

    https://gist.github.com/1499621


With a repo with 1 million files (but few commits), the diff drops the
commit time down from 7.3 seconds to 1.8 seconds, a 75% decrease. The
optimizations are:

I do not know if these kind of changes are called "optimizations" or
merely making the command record a random tree object that may have some
resemblance to what you wanted to commit but is subtly incorrect. I didn't
fetch your safety removal, though.

Wouldn't you get a similar speed-up without being unsafe if you simply ran
"git commit" without any parameter (i.e. write out the current index as a
tree and make a commit), combined with "--no-status" and perhaps "-q" to
avoid running the comparison between the resulting commit and the working
tree state after the commit?