8 files changed, 301 insertions, 16 deletions

diff --git a/t/perf/README b/t/perf/README
index 8848c14619..49ea4349be 100644
--- a/t/perf/README
+++ b/t/perf/README
@@ -115,8 +115,16 @@ After that you will want to use some of the following:
 
 At least one of the first two is required!
 
-You can use test_expect_success as usual.  For actual performance
-tests, use
+You can use test_expect_success as usual. In both test_expect_success
+and in test_perf, running "git" points to the version that is being
+perf-tested. The $MODERN_GIT variable points to the git wrapper for the
+currently checked-out version (i.e., the one that matches the t/perf
+scripts you are running).  This is useful if your setup uses commands
+that only work with newer versions of git than what you might want to
+test (but obviously your new commands must still create a state that can
+be used by the older version of git you are testing).
+
+For actual performance tests, use
 
 	test_perf 'descriptive string' '
 		command1 &&
diff --git a/t/perf/p3400-rebase.sh b/t/perf/p3400-rebase.sh
new file mode 100755
index 0000000000..b3e7d525d2
--- /dev/null
+++ b/t/perf/p3400-rebase.sh
@@ -0,0 +1,36 @@
+#!/bin/sh
+
+test_description='Tests rebase performance'
+. ./perf-lib.sh
+
+test_perf_default_repo
+
+test_expect_success 'setup' '
+	git checkout -f -b base &&
+	git checkout -b to-rebase &&
+	git checkout -b upstream &&
+	for i in $(seq 100)
+	do
+		# simulate huge diffs
+		echo change$i >unrelated-file$i &&
+		seq 1000 >>unrelated-file$i &&
+		git add unrelated-file$i &&
+		test_tick &&
+		git commit -m commit$i unrelated-file$i &&
+		echo change$i >unrelated-file$i &&
+		seq 1000 | tac >>unrelated-file$i &&
+		git add unrelated-file$i &&
+		test_tick &&
+		git commit -m commit$i-reverse unrelated-file$i ||
+		break
+	done &&
+	git checkout to-rebase &&
+	test_commit our-patch interesting-file
+'
+
+test_perf 'rebase on top of a lot of unrelated changes' '
+	git rebase --onto upstream HEAD^ &&
+	git rebase --onto base HEAD^
+'
+
+test_done
diff --git a/t/perf/p3404-rebase-interactive.sh b/t/perf/p3404-rebase-interactive.sh
new file mode 100755
index 0000000000..88f47de282
--- /dev/null
+++ b/t/perf/p3404-rebase-interactive.sh
@@ -0,0 +1,36 @@
+#!/bin/sh
+
+test_description='Tests rebase -i performance'
+. ./perf-lib.sh
+
+test_perf_default_repo
+
+# This commit merges a sufficiently long topic branch for reasonable
+# performance testing
+branch_merge=ba5312da19c6fdb6c6747d479f58932aae6e900c^{commit}
+export branch_merge
+
+git rev-parse --verify $branch_merge >/dev/null 2>&1 || {
+	skip_all='skipping because $branch_merge was not found'
+	test_done
+}
+
+write_script swap-first-two.sh <<\EOF
+case "$1" in
+*/COMMIT_EDITMSG)
+	mv "$1" "$1".bak &&
+	sed -e '1{h;d}' -e 2G <"$1".bak >"$1"
+	;;
+esac
+EOF
+
+test_expect_success 'setup' '
+	git config core.editor "\"$PWD"/swap-first-two.sh\" &&
+	git checkout -f $branch_merge^2
+'
+
+test_perf 'rebase -i' '
+	git rebase -i $branch_merge^
+'
+
+test_done
diff --git a/t/perf/p4211-line-log.sh b/t/perf/p4211-line-log.sh
index 3d074b0e41..b7ff68d4fa 100755
--- a/t/perf/p4211-line-log.sh
+++ b/t/perf/p4211-line-log.sh
@@ -23,11 +23,11 @@ test_perf 'git log --follow (baseline for -M)' '
 	git log --oneline --follow -- "$file" >/dev/null
 '
 
-test_perf 'git log -L' '
-	git log -L 1:"$file" >/dev/null
+test_perf 'git log -L (renames off)' '
+	git log --no-renames -L 1:"$file" >/dev/null
 '
 
-test_perf 'git log -M -L' '
+test_perf 'git log -L (renames on)' '
 	git log -M -L 1:"$file" >/dev/null
 '
 
diff --git a/t/perf/p5303-many-packs.sh b/t/perf/p5303-many-packs.sh
new file mode 100755
index 0000000000..3779851941
--- /dev/null
+++ b/t/perf/p5303-many-packs.sh
@@ -0,0 +1,87 @@
+#!/bin/sh
+
+test_description='performance with large numbers of packs'
+. ./perf-lib.sh
+
+test_perf_large_repo
+
+# A real many-pack situation would probably come from having a lot of pushes
+# over time. We don't know how big each push would be, but we can fake it by
+# just walking the first-parent chain and having every 5 commits be their own
+# "push". This isn't _entirely_ accurate, as real pushes would have some
+# duplicate objects due to thin-pack fixing, but it's a reasonable
+# approximation.
+#
+# And then all of the rest of the objects can go in a single packfile that
+# represents the state before any of those pushes (actually, we'll generate
+# that first because in such a setup it would be the oldest pack, and we sort
+# the packs by reverse mtime inside git).
+repack_into_n () {
+	rm -rf staging &&
+	mkdir staging &&
+
+	git rev-list --first-parent HEAD |
+	sed -n '1~5p' |
+	head -n "$1" |
+	perl -e 'print reverse <>' \
+	>pushes
+
+	# create base packfile
+	head -n 1 pushes |
+	git pack-objects --delta-base-offset --revs staging/pack
+
+	# and then incrementals between each pair of commits
+	last= &&
+	while read rev
+	do
+		if test -n "$last"; then
+			{
+				echo "$rev" &&
+				echo "^$last"
+			} |
+			git pack-objects --delta-base-offset --revs \
+				staging/pack || return 1
+		fi
+		last=$rev
+	done <pushes &&
+
+	# and install the whole thing
+	rm -f .git/objects/pack/* &&
+	mv staging/* .git/objects/pack/
+}
+
+# Pretend we just have a single branch and no reflogs, and that everything is
+# in objects/pack; that makes our fake pack-building via repack_into_n()
+# much simpler.
+test_expect_success 'simplify reachability' '
+	tip=$(git rev-parse --verify HEAD) &&
+	git for-each-ref --format="option no-deref%0adelete %(refname)" |
+	git update-ref --stdin &&
+	rm -rf .git/logs &&
+	git update-ref refs/heads/master $tip &&
+	git symbolic-ref HEAD refs/heads/master &&
+	git repack -ad
+'
+
+for nr_packs in 1 50 1000
+do
+	test_expect_success "create $nr_packs-pack scenario" '
+		repack_into_n $nr_packs
+	'
+
+	test_perf "rev-list ($nr_packs)" '
+		git rev-list --objects --all >/dev/null
+	'
+
+	# This simulates the interesting part of the repack, which is the
+	# actual pack generation, without smudging the on-disk setup
+	# between trials.
+	test_perf "repack ($nr_packs)" '
+		git pack-objects --keep-true-parents \
+		  --honor-pack-keep --non-empty --all \
+		  --reflog --indexed-objects --delta-base-offset \
+		  --stdout </dev/null >/dev/null
+	'
+done
+
+test_done
diff --git a/t/perf/p5550-fetch-tags.sh b/t/perf/p5550-fetch-tags.sh
new file mode 100755
index 0000000000..a5dc39f86a
--- /dev/null
+++ b/t/perf/p5550-fetch-tags.sh
@@ -0,0 +1,99 @@
+#!/bin/sh
+
+test_description='performance of tag-following with many tags
+
+This tests a fairly pathological case, so rather than rely on a real-world
+case, we will construct our own repository. The situation is roughly as
+follows.
+
+The parent repository has a large number of tags which are disconnected from
+the rest of history. That makes them candidates for tag-following, but we never
+actually grab them (and thus they will impact each subsequent fetch).
+
+The child repository is a clone of parent, without the tags, and is at least
+one commit behind the parent (meaning that we will fetch one object and then
+examine the tags to see if they need followed). Furthermore, it has a large
+number of packs.
+
+The exact values of "large" here are somewhat arbitrary; I picked values that
+start to show a noticeable performance problem on my machine, but without
+taking too long to set up and run the tests.
+'
+. ./perf-lib.sh
+
+# make a long nonsense history on branch $1, consisting of $2 commits, each
+# with a unique file pointing to the blob at $2.
+create_history () {
+	perl -le '
+		my ($branch, $n, $blob) = @ARGV;
+		for (1..$n) {
+			print "commit refs/heads/$branch";
+			print "committer nobody <nobody@example.com> now";
+			print "data 4";
+			print "foo";
+			print "M 100644 $blob $_";
+		}
+	' "$@" |
+	git fast-import --date-format=now
+}
+
+# make a series of tags, one per commit in the revision range given by $@
+create_tags () {
+	git rev-list "$@" |
+	perl -lne 'print "create refs/tags/$. $_"' |
+	git update-ref --stdin
+}
+
+# create $1 nonsense packs, each with a single blob
+create_packs () {
+	perl -le '
+		my ($n) = @ARGV;
+		for (1..$n) {
+			print "blob";
+			print "data <<EOF";
+			print "$_";
+			print "EOF";
+		}
+	' "$@" |
+	git fast-import &&
+
+	git cat-file --batch-all-objects --batch-check='%(objectname)' |
+	while read sha1
+	do
+		echo $sha1 | git pack-objects .git/objects/pack/pack
+	done
+}
+
+test_expect_success 'create parent and child' '
+	git init parent &&
+	git -C parent commit --allow-empty -m base &&
+	git clone parent child &&
+	git -C parent commit --allow-empty -m trigger-fetch
+'
+
+test_expect_success 'populate parent tags' '
+	(
+		cd parent &&
+		blob=$(echo content | git hash-object -w --stdin) &&
+		create_history cruft 3000 $blob &&
+		create_tags cruft &&
+		git branch -D cruft
+	)
+'
+
+test_expect_success 'create child packs' '
+	(
+		cd child &&
+		git config gc.auto 0 &&
+		git config gc.autopacklimit 0 &&
+		create_packs 500
+	)
+'
+
+test_perf 'fetch' '
+	# make sure there is something to fetch on each iteration
+	git -C child update-ref -d refs/remotes/origin/master &&
+	git -C child fetch
+'
+
+test_done
diff --git a/t/perf/perf-lib.sh b/t/perf/perf-lib.sh
index 5cf74eddec..46f08ee087 100644
--- a/t/perf/perf-lib.sh
+++ b/t/perf/perf-lib.sh
@@ -52,6 +52,9 @@ TEST_NO_MALLOC_CHECK=t
 # need to export them for test_perf subshells
 export TEST_DIRECTORY TRASH_DIRECTORY GIT_BUILD_DIR GIT_TEST_CMP
 
+MODERN_GIT=$GIT_BUILD_DIR/bin-wrappers/git
+export MODERN_GIT
+
 perf_results_dir=$TEST_OUTPUT_DIRECTORY/test-results
 mkdir -p "$perf_results_dir"
 rm -f "$perf_results_dir"/$(basename "$0" .sh).subtests
@@ -80,23 +83,29 @@ test_perf_create_repo_from () {
 	error "bug in the test script: not 2 parameters to test-create-repo"
 	repo="$1"
 	source="$2"
-	source_git=$source/$(cd "$source" && git rev-parse --git-dir)
+	source_git="$(git -C "$source" rev-parse --git-dir)"
+	objects_dir="$("$MODERN_GIT" -C "$source" rev-parse --git-path objects)"
 	mkdir -p "$repo/.git"
 	(
-		cd "$repo/.git" &&
-		{ cp -Rl "$source_git/objects" . 2>/dev/null ||
-			cp -R "$source_git/objects" .; } &&
+		cd "$source" &&
+		{ cp -Rl "$objects_dir" "$repo/.git/" 2>/dev/null ||
+			cp -R "$objects_dir" "$repo/.git/"; } &&
 		for stuff in "$source_git"/*; do
 			case "$stuff" in
-				*/objects|*/hooks|*/config)
+				*/objects|*/hooks|*/config|*/commondir)
 					;;
 				*)
-					cp -R "$stuff" . || exit 1
+					cp -R "$stuff" "$repo/.git/" || exit 1
 					;;
 			esac
-		done &&
-		cd .. &&
-		git init -q &&
+		done
+	) &&
+	(
+		cd "$repo" &&
+		git init -q && {
+			test_have_prereq SYMLINKS ||
+			git config core.symlinks false
+		} &&
 		mv .git/hooks .git/hooks-disabled 2>/dev/null
 	) || error "failed to copy repository '$source' to '$repo'"
 }
@@ -121,11 +130,15 @@ test_checkout_worktree () {
 # Performance tests should never fail.  If they do, stop immediately
 immediate=t
 
+# Perf tests require GNU time
+case "$(uname -s)" in Darwin) GTIME="${GTIME:-gtime}";; esac
+GTIME="${GTIME:-/usr/bin/time}"
+
 test_run_perf_ () {
 	test_cleanup=:
 	test_export_="test_cleanup"
 	export test_cleanup test_export_
-	/usr/bin/time -f "%E %U %S" -o test_time.$i "$SHELL" -c '
+	"$GTIME" -f "%E %U %S" -o test_time.$i "$SHELL" -c '
 . '"$TEST_DIRECTORY"/test-lib-functions.sh'
 test_export () {
 	[ $# != 0 ] || return 0
diff --git a/t/perf/run b/t/perf/run
index cfd70129bb..e8adedadfd 100755
--- a/t/perf/run
+++ b/t/perf/run
@@ -30,7 +30,13 @@ unpack_git_rev () {
 }
 build_git_rev () {
 	rev=$1
-	cp ../../config.mak build/$rev/config.mak
+	for config in config.mak config.mak.autogen config.status
+	do
+		if test -e "../../$config"
+		then
+			cp "../../$config" "build/$rev/"
+		fi
+	done
 	(cd build/$rev && make $GIT_PERF_MAKE_OPTS) ||
 	die "failed to build revision '$mydir'"
 }