Hi, this is the second version of my patch series which aims to speed up mirror-fetches in repos with huge amounts of refs. The only change compared to v1 is a fixed up commit message: Taylor has pointed out to me that commit dates retrieved from the commit-graph are not in fact the corrected commit dates, which are stored separately. Patrick Patrick Steinhardt (2): fetch-pack: use commit-graph when computing cutoff fetch: skip computing output width when not printing anything builtin/fetch.c | 8 ++++++-- fetch-pack.c | 28 ++++++++++++++++------------ 2 files changed, 22 insertions(+), 14 deletions(-) Range-diff against v1: 1: 31cf8f87a1 ! 1: 6fac914f0f fetch-pack: use commit-graph when computing cutoff @@ Commit message the cutoff date. This can be sped up by trying to look up commits via the commit-graph first, which is a lot more efficient. - One thing to keep in mind though is that the commit-graph corrects - committer dates: - - * A commit with at least one parent has corrected committer date - equal to the maximum of its commiter date and one more than the - largest corrected committer date among its parents. - - As a result, it may be that the commit date we load via the commit graph - is more recent than it would have been when loaded via the ODB, and as a - result we may also choose a more recent cutoff point. But as the code - documents, this is only a heuristic and it is okay if we determine a - wrong cutoff date. The worst that can happen is that we report more - commits as HAVEs to the server when using corrected dates. - - Loading commits via the commit-graph is typically much faster than - loading commits via the object database. Benchmarks in a repository with - about 2,1 million refs and an up-to-date commit-graph show a 20% speedup - when mirror-fetching: + Benchmarks in a repository with about 2,1 million refs and an up-to-date + commit-graph show a 20% speedup when mirror-fetching: Benchmark 1: git fetch --atomic +refs/*:refs/* (v2.35.0) Time (mean ± σ): 75.264 s ± 1.115 s [User: 68.199 s, System: 10.094 s] 2: 5a3fd3232f = 2: 4b9bbcf795 fetch: skip computing output width when not printing anything -- 2.35.1