[PATCH 0/2] maintenance: handle geometric repack tasks with promisor pack(s)

[PATCH 0/2] maintenance: handle geometric repack tasks with promisor pack(s)

[Taylor Blau]

The geometric-repack maintenance task predates support for keeping
promisor packs in their own geometric progression. After that support
was added in dcc9c7ef47 (builtin/repack: handle promisor packs with
geometric repacking, 2026-01-05), the maintenance task still made two
decisions from the ordinary-pack progression alone:

 - whether an explicit run should use `--geometric` or its
   all-into-one fallback; and

 - whether `--auto` sees enough work to run the task at all.

That can make partial clones rewrite more than necessary. If the
ordinary packs would all be rolled up, the task can choose the
all-into-one path even when the promisor progression would leave a
large pack alone. Likewise, an all-promisor repository can have a
promisor rollup ready while `--auto` sees neither an ordinary split
nor enough loose objects and skips the task.

The first patch makes the repack-mode choice consider both
progressions. It keeps the all-into-one fallback only when neither
progression leaves a pack above its split, so the fallback does not
rewrite packs that geometric repack would have kept.

The second patch makes the `--auto` condition consider
`geometry.promisor_split` alongside `geometry.split`. A non-zero split
on either side means that geometric repack can combine at least two
packs.

Both tests build three promisor packs whose object counts cause the two
smaller packs to roll up while leaving the large pack intact. The
`--auto` test uses a high loose-object threshold, so the promisor split
is the only reason the task runs.

Thanks in advance for your review!

Taylor Blau (2):
  maintenance: account for promisor pack geometry
  maintenance: trigger --auto for promisor rollups

 builtin/gc.c                  |  5 +--
 t/t5331-pack-objects-stdin.sh |  3 +-
 t/t7900-maintenance.sh        | 68 +++++++++++++++++++++++++++++++++++
 3 files changed, 73 insertions(+), 3 deletions(-)


base-commit: a97fcc37c2bc6340a8d7ce78dedf227aac4e9aa7
-- 
2.55.0.483.gdc2fffc37c

[PATCH 1/2] maintenance: account for promisor pack geometry

[Taylor Blau]

Commit 9bc151850c (builtin/maintenance: introduce
"geometric-repack" task, 2025-10-24) added a new maintenance task to
perform either a geometric repack, or an all-into-one repack if the
geometric repack would itself produce a single pack.

Some time later, commit dcc9c7ef47 (builtin/repack: handle promisor
packs with geometric repacking, 2026-01-05) taught the geometric
repacking machinery to separate promisor packs from ordinary ones, but
did not update the maintenance task accordingly.

As a consequence, the geometric-repack maintenance task only considers
the non-promisor pack progression. It falls back to all-into-one
whenever a geometric repack would roll up all non-promisor packs into a
single pack, even if the promisor progression would keep a large pack
and roll up only smaller ones.

Check both progressions before choosing the repack mode. If either
leaves a pack above its split, geometric repack still avoids rewriting
that pack, whereas the all-into-one fallback would rewrite it. Use the
fallback only when neither progression leaves a pack behind. That
preserves the reason for the fallback: let the all-into-one repack
handle unreachable objects when it is not rewriting more packs than the
geometric repack.

Signed-off-by: Taylor Blau <ttaylorr@openai.com>
---
 builtin/gc.c           |  3 ++-
 t/t7900-maintenance.sh | 45 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/builtin/gc.c b/builtin/gc.c
index 49c8474fad..ed75c12c43 100644
--- a/builtin/gc.c
+++ b/builtin/gc.c
@@ -1593,7 +1593,8 @@ static int maintenance_task_geometric_repack(struct maintenance_run_opts *opts,
 	child.odb_to_close = the_repository->objects;
 
 	strvec_pushl(&child.args, "repack", "-d", "-l", NULL);
-	if (geometry.split < geometry.pack_nr)
+	if (geometry.split < geometry.pack_nr ||
+	    geometry.promisor_split < geometry.promisor_pack_nr)
 		strvec_pushf(&child.args, "--geometric=%d",
 			     geometry.split_factor);
 	else
diff --git a/t/t7900-maintenance.sh b/t/t7900-maintenance.sh
index a8d691719d..ba5b359e77 100755
--- a/t/t7900-maintenance.sh
+++ b/t/t7900-maintenance.sh
@@ -659,6 +659,51 @@ test_expect_success 'geometric repacking task' '
 	)
 '
 
+objdir=.git/objects
+packdir=$objdir/pack
+
+pack_promisor () {
+	p="$(echo "$@" | git pack-objects --revs $packdir/pack)" &&
+	touch "$packdir/pack-$p.promisor" &&
+	echo "$p"
+}
+
+test_expect_success 'geometric repacking task handles promisor packs' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		git config set maintenance.auto false &&
+		git remote add promisor garbage &&
+		git config set remote.promisor.promisor true &&
+
+		for n in $(test_seq 6)
+		do
+			test_commit $n || return 1
+		done &&
+
+		A="$(pack_promisor 1)" &&
+		B="$(pack_promisor 1..2)" &&
+		C="$(pack_promisor 2..6)" &&
+		git prune-packed &&
+
+		ls $packdir/pack-*.promisor | sort >promisors.before &&
+		GIT_TRACE2_EVENT="$(pwd)/trace2.txt" \
+			git maintenance run --quiet --task=geometric-repack &&
+		ls $packdir/pack-*.promisor | sort >promisors.after &&
+
+		test_subcommand git repack -d -l --geometric=2 \
+			--quiet --write-midx <trace2.txt &&
+
+		test_line_count = 2 promisors.after &&
+
+		printf "$packdir/pack-%s.promisor\n" "$A" "$B" | sort >expect &&
+		comm -23 promisors.before promisors.after >actual &&
+
+		test_cmp expect actual
+	)
+'
+
 test_geometric_repack_needed () {
 	NEEDED="$1"
 	GEOMETRIC_CONFIG="$2" &&
-- 
2.55.0.483.gdc2fffc37c

[PATCH 2/2] maintenance: trigger --auto for promisor rollups

[Taylor Blau]

Commit 9bc151850c (builtin/maintenance: introduce "geometric-repack"
task, 2025-10-24) added an auto condition for the geometric-repack
task. It runs the task when ordinary packs need to be combined or when
the number of loose objects crosses the configured threshold.

Later on in commit dcc9c7ef47 (builtin/repack: handle promisor packs
with geometric repacking, 2026-01-05), the geometric repack machinery
started handling promisor packs separately, but did not correspondingly
update the auto condition.

As a result, a repository can have promisor packs ready to combine
while its non-promisor packs and loose object count require no work. In
that case, `--auto` skips the task even though a geometric repack
would combine at least two promisor packs.

Check `geometry.promisor_split` alongside `geometry.split`.

There is some fallout in t5331: the new condition makes a filtered
clone eligible for auto-maintenance before the test inspects its
promisor packs. Disable auto-maintenance in that fixture so it
continues to test `--stdin-packs`, not the maintenance task.

Signed-off-by: Taylor Blau <ttaylorr@openai.com>
---
 builtin/gc.c                  |  2 +-
 t/t5331-pack-objects-stdin.sh |  3 ++-
 t/t7900-maintenance.sh        | 23 +++++++++++++++++++++++
 3 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/builtin/gc.c b/builtin/gc.c
index ed75c12c43..e9572940dc 100644
--- a/builtin/gc.c
+++ b/builtin/gc.c
@@ -1649,7 +1649,7 @@ static int geometric_repack_auto_condition(struct gc_config *cfg UNUSED)
 	 * When we'd merge at least two packs with one another we always
 	 * perform the repack.
 	 */
-	if (geometry.split) {
+	if (geometry.split || geometry.promisor_split) {
 		ret = 1;
 		goto out;
 	}
diff --git a/t/t5331-pack-objects-stdin.sh b/t/t5331-pack-objects-stdin.sh
index c74b5861af..2a983e28ac 100755
--- a/t/t5331-pack-objects-stdin.sh
+++ b/t/t5331-pack-objects-stdin.sh
@@ -368,7 +368,8 @@ test_expect_success '--stdin-packs does not perform backfill fetch' '
 	git -C remote config set --local uploadpack.allowfilter 1 &&
 	git -C remote config set --local uploadpack.allowanysha1inwant 1 &&
 
-	git clone --filter=tree:0 "file://$(pwd)/remote" client &&
+	git -c maintenance.auto=false clone --filter=tree:0 \
+		"file://$(pwd)/remote" client &&
 	(
 		cd client &&
 		ls .git/objects/pack/*.promisor | sed "s|.*/||; s/\.promisor$/.pack/" >packs &&
diff --git a/t/t7900-maintenance.sh b/t/t7900-maintenance.sh
index ba5b359e77..fb5f2d8902 100755
--- a/t/t7900-maintenance.sh
+++ b/t/t7900-maintenance.sh
@@ -759,6 +759,29 @@ test_expect_success 'geometric repacking with --auto' '
 	)
 '
 
+test_expect_success 'geometric repacking with --auto handles promisor packs' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		git config set maintenance.auto false &&
+		git remote add promisor garbage &&
+		git config set remote.promisor.promisor true &&
+
+		for n in $(test_seq 6)
+		do
+			test_commit $n || return 1
+		done &&
+
+		pack_promisor 1 >/dev/null &&
+		pack_promisor 1..2 >/dev/null &&
+		pack_promisor 2..6 >/dev/null &&
+		git prune-packed &&
+
+		test_geometric_repack_needed true auto=9000
+	)
+'
+
 test_expect_success 'geometric repacking honors configured split factor' '
 	test_when_finished "rm -rf repo" &&
 	git init repo &&
-- 
2.55.0.483.gdc2fffc37c