On Tue, Jun 29, 2021 at 09:31:59PM -0400, Jeff King wrote:

If I run "git rev-list --not --all --stdin </dev/null" in linux.git, it
takes about 35ms. But if I make a ton of refs, like:

The "--stdin" should be before "--not", of course, to mimic a real
connectivity check. But it doesn't matter in this case because we're
feeding an empty input. :)

-Peff