Like many dev shops, we run a CI server that basically does:
git fetch $some_branch &&
git checkout $some_branch &&
make test
all day long. Sometimes the fetches would get very slow, and the problem
turned out to be a combination of:
1. Never running "git gc". This means you can end up with a ton of
loose objects, or even a bunch of small packs[1].
2. One of the loops in fetch caused us to re-scan the entire
objects/pack directory repeatedly, proportional to the number of
refs on the remote.
I think the fundamental fix is to gc more often, as it makes the re-scans
less expensive, along with making general object lookup faster. But the
repeated re-scans strike me as kind of hacky. This series tries to
address both:
[1/2]: fetch: run gc --auto after fetching
[2/2]: fetch-pack: avoid repeatedly re-scanning pack directory
-Peff
[1] It turns out we had our transfer.unpacklimit set unreasonably low,
leading to a large number of tiny packs, but even with the defaults,
you will end up with a ton of loose objects if you do repeated small
fetches.
--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html