From 911016f419cb449e2ab8b026699e882ab3862bb2 Mon Sep 17 00:00:00 2001 From: Patrick Steinhardt Date: Fri, 20 Feb 2026 11:15:12 +0100 Subject: [PATCH] builtin/maintenance: use "geometric" strategy by default The git-gc(1) command has been introduced in the early days of Git in 30f610b7b0 (Create 'git gc' to perform common maintenance operations., 2006-12-27) as the main repository maintenance utility. And while the tool has of course evolved since then to cover new parts, the basic strategy it uses has never really changed much. It is safe to say that since 2006 the Git ecosystem has changed quite a bit. Repositories tend to be much larger nowadays than they have been almost 20 years ago, and large parts of the industry went crazy for monorepos (for various wildly different definitions of "monorepo"). So the maintenance strategy we used back then may not be the best fit nowadays anymore. Arguably, most of the maintenance tasks that git-gc(1) does are still perfectly fine today: repacking references, expiring various data structures and things like tend to not cause huge problems. But the big exception is the way we repack objects. git-gc(1) by default uses a split strategy: it performs incremental repacks by default, and then whenever we have too many packs we perform a large all-into-one repack. This all-into-one repack is what is causing problems nowadays, as it is an operation that is quite expensive. While it is wasteful in small- and medium-sized repositories, in large repos it may even be prohibitively expensive. We have eventually introduced git-maintenance(1) that was slated as a replacement for git-gc(1). In contrast to git-gc(1), it was much more flexible as it is structured around configurable tasks and strategies. And while it knows about the "incremental" strategy that we may use for scheduled maintenance when configured via Scalar, its default still is to use git-gc(1) in the background. The "incremental" strategy isn't really a full replacement for git-gc(1) though, as it doesn't know to expire unused data structures. In Git 2.52 we have thus introduced a new "geometric" strategy that is a proper replacement for the old git-gc(1). In contrast to the incremental/all-into-one split used by git-gc(1), the new "geometric" strategy maintains a geometric progression of packfiles, which significantly reduces the number of all-into-one repacks that we have to perform in large repositories. It is thus a much better fit for large repositories than git-gc(1). Note that the "geometric" strategy isn't perfect though: while we perform way less all-into-one repacks compared to git-gc(1), we still have to perform them eventually. But for the largest repositories out there this may not be an option, as client machines might not be powerful enough to perform such a repack in the first place. These cases would thus still be covered by Scalar's "incremental" strategy. Switch the default strategy away from "gc" to "geometric", but retain the "incremental" strategy configured by Scalar. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano --- builtin/gc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/builtin/gc.c b/builtin/gc.c index 4390eee6ec..fb329c2cff 100644 --- a/builtin/gc.c +++ b/builtin/gc.c @@ -1980,7 +1980,7 @@ static void initialize_task_config(struct maintenance_run_opts *opts, strategy = none_strategy; type = MAINTENANCE_TYPE_SCHEDULED; } else { - strategy = gc_strategy; + strategy = geometric_strategy; type = MAINTENANCE_TYPE_MANUAL; }