On Thu, Oct 31, 2024 at 07:47:31AM -0400, Jeff King wrote:

On Tue, Oct 29, 2024 at 09:43:22PM -0700, Josh Poimboeuf wrote:

quoted

$ time git describe --match=v6.10-rc7 --debug
describe HEAD
No exact match on refs or tags, searching to describe
finished search at d8470b7c13e11c18cf14a7e3180f0b00e715e4f0
 annotated       1844 v6.10-rc7
traversed 1282750 commits
v6.10-rc7-1844-gc61e41121036

real	0m9.243s
user	0m8.940s
sys	0m0.268s

$ time git describe
v6.10-rc7-1844-gc61e41121036

real	0m0.149s
user	0m0.111s
sys	0m0.036s

There's more discussion of the actual solution in the nearby thread from
Rasmus. But I did want to note one thing here: when I initially tried to
reproduce your problem, my "slow" case was a lot less bad.

The reason is that I had a commit graph file to speed up traversal. So
independent of the git-describe fix, you might want to try:

  git commit-graph write --reachable

That reduces the slow case for me by a factor of 10. And likewise other
traversal operations should get faster.

I think we'll build the commit graph file by default these days when you
run "git gc". But we don't build it immediately after cloning. Perhaps
we should change that.

Hm... I actually ran "git gc" and it didn't seem to help at all.

-- 
Josh