8 files changed, 359 insertions, 38 deletions
diff --git a/t/perf/aggregate.perl b/t/perf/aggregate.perl
index 1dbc85b214..e401208488 100755
--- a/t/perf/aggregate.perl
+++ b/t/perf/aggregate.perl
@@ -69,12 +69,17 @@ if (not @tests) {
 	@tests = glob "p????-*.sh";
 }
 
+my $resultsdir = "test-results";
+if ($ENV{GIT_PERF_SUBSECTION} ne "") {
+	$resultsdir .= "/" . $ENV{GIT_PERF_SUBSECTION};
+}
+
 my @subtests;
 my %shorttests;
 for my $t (@tests) {
 	$t =~ s{(?:.*/)?(p(\d+)-[^/]+)\.sh$}{$1} or die "bad test name: $t";
 	my $n = $2;
-	my $fname = "test-results/$t.subtests";
+	my $fname = "$resultsdir/$t.subtests";
 	open my $fp, "<", $fname or die "cannot open $fname: $!";
 	for (<$fp>) {
 		chomp;
@@ -98,7 +103,7 @@ sub read_descr {
 my %descrs;
 my $descrlen = 4; # "Test"
 for my $t (@subtests) {
-	$descrs{$t} = $shorttests{$t}.": ".read_descr("test-results/$t.descr");
+	$descrs{$t} = $shorttests{$t}.": ".read_descr("$resultsdir/$t.descr");
 	$descrlen = length $descrs{$t} if length $descrs{$t}>$descrlen;
 }
 
@@ -138,7 +143,7 @@ for my $t (@subtests) {
 	my $firstr;
 	for my $i (0..$#dirs) {
 		my $d = $dirs[$i];
-		$times{$prefixes{$d}.$t} = [get_times("test-results/$prefixes{$d}$t.times")];
+		$times{$prefixes{$d}.$t} = [get_times("$resultsdir/$prefixes{$d}$t.times")];
 		my ($r,$u,$s) = @{$times{$prefixes{$d}.$t}};
 		my $w = length format_times($r,$u,$s,$firstr);
 		$colwidth[$i] = $w if $w > $colwidth[$i];
diff --git a/t/perf/lib-pack.sh b/t/perf/lib-pack.sh
new file mode 100644
index 0000000000..d3865db286
--- /dev/null
+++ b/t/perf/lib-pack.sh
@@ -0,0 +1,25 @@
+# Helpers for dealing with large numbers of packs.
+
+# 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";
+			print "checkpoint"
+		}
+	' "$@" |
+	git fast-import
+}
+
+# create a large number of packs, disabling any gc which might
+# cause us to repack them
+setup_many_packs () {
+	git config gc.auto 0 &&
+	git config gc.autopacklimit 0 &&
+	git config fastimport.unpacklimit 0 &&
+	create_packs 500
+}
diff --git a/t/perf/p4211-line-log.sh b/t/perf/p4211-line-log.sh
index e0ed05907c..392bcc0e51 100755
--- a/t/perf/p4211-line-log.sh
+++ b/t/perf/p4211-line-log.sh
@@ -35,4 +35,8 @@ test_perf 'git log --oneline --raw --parents' '
 	git log --oneline --raw --parents >/dev/null
 '
 
+test_perf 'git log --oneline --raw --parents -1000' '
+	git log --oneline --raw --parents -1000 >/dev/null
+'
+
 test_done
diff --git a/t/perf/p5550-fetch-tags.sh b/t/perf/p5550-fetch-tags.sh
index a5dc39f86a..d0e0e019ea 100755
--- a/t/perf/p5550-fetch-tags.sh
+++ b/t/perf/p5550-fetch-tags.sh
@@ -20,6 +20,7 @@ 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
+. "$TEST_DIRECTORY/perf/lib-pack.sh"
 
 # make a long nonsense history on branch $1, consisting of $2 commits, each
 # with a unique file pointing to the blob at $2.
@@ -44,26 +45,6 @@ create_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 &&
@@ -84,9 +65,7 @@ test_expect_success 'populate parent tags' '
 test_expect_success 'create child packs' '
 	(
 		cd child &&
-		git config gc.auto 0 &&
-		git config gc.autopacklimit 0 &&
-		create_packs 500
+		setup_many_packs
 	)
 '
 
diff --git a/t/perf/p5551-fetch-rescan.sh b/t/perf/p5551-fetch-rescan.sh
new file mode 100755
index 0000000000..b99dc23e32
--- /dev/null
+++ b/t/perf/p5551-fetch-rescan.sh
@@ -0,0 +1,55 @@
+#!/bin/sh
+
+test_description='fetch performance with many packs
+
+It is common for fetch to consider objects that we might not have, and it is an
+easy mistake for the code to use a function like `parse_object` that might
+give the correct _answer_ on such an object, but do so slowly (due to
+re-scanning the pack directory for lookup failures).
+
+The resulting performance drop can be hard to notice in a real repository, but
+becomes quite large in a repository with a large number of packs. So this
+test creates a more pathological case, since any mistakes would produce a more
+noticeable slowdown.
+'
+. ./perf-lib.sh
+. "$TEST_DIRECTORY"/perf/lib-pack.sh
+
+test_expect_success 'create parent and child' '
+	git init parent &&
+	git clone parent child
+'
+
+
+test_expect_success 'create refs in the parent' '
+	(
+		cd parent &&
+		git commit --allow-empty -m foo &&
+		head=$(git rev-parse HEAD) &&
+		test_seq 1000 |
+		sed "s,.*,update refs/heads/& $head," |
+		$MODERN_GIT update-ref --stdin
+	)
+'
+
+test_expect_success 'create many packs in the child' '
+	(
+		cd child &&
+		setup_many_packs
+	)
+'
+
+test_perf 'fetch' '
+	# start at the same state for each iteration
+	obj=$($MODERN_GIT -C parent rev-parse HEAD) &&
+	(
+		cd child &&
+		$MODERN_GIT for-each-ref --format="delete %(refname)" refs/remotes |
+		$MODERN_GIT update-ref --stdin &&
+		rm -vf .git/objects/$(echo $obj | sed "s|^..|&/|") &&
+
+		git fetch
+	)
+'
+
+test_done
diff --git a/t/perf/p7519-fsmonitor.sh b/t/perf/p7519-fsmonitor.sh
new file mode 100755
index 0000000000..16d1bf72e5
--- /dev/null
+++ b/t/perf/p7519-fsmonitor.sh
@@ -0,0 +1,184 @@
+#!/bin/sh
+
+test_description="Test core.fsmonitor"
+
+. ./perf-lib.sh
+
+#
+# Performance test for the fsmonitor feature which enables git to talk to a
+# file system change monitor and avoid having to scan the working directory
+# for new or modified files.
+#
+# By default, the performance test will utilize the Watchman file system
+# monitor if it is installed.  If Watchman is not installed, it will use a
+# dummy integration script that does not report any new or modified files.
+# The dummy script has very little overhead which provides optimistic results.
+#
+# The performance test will also use the untracked cache feature if it is
+# available as fsmonitor uses it to speed up scanning for untracked files.
+#
+# There are 3 environment variables that can be used to alter the default
+# behavior of the performance test:
+#
+# GIT_PERF_7519_UNTRACKED_CACHE: used to configure core.untrackedCache
+# GIT_PERF_7519_SPLIT_INDEX: used to configure core.splitIndex
+# GIT_PERF_7519_FSMONITOR: used to configure core.fsMonitor
+#
+# The big win for using fsmonitor is the elimination of the need to scan the
+# working directory looking for changed and untracked files. If the file
+# information is all cached in RAM, the benefits are reduced.
+#
+# GIT_PERF_7519_DROP_CACHE: if set, the OS caches are dropped between tests
+#
+
+test_perf_large_repo
+test_checkout_worktree
+
+test_lazy_prereq UNTRACKED_CACHE '
+	{ git update-index --test-untracked-cache; ret=$?; } &&
+	test $ret -ne 1
+'
+
+test_lazy_prereq WATCHMAN '
+	{ command -v watchman >/dev/null 2>&1; ret=$?; } &&
+	test $ret -ne 1
+'
+
+if test_have_prereq WATCHMAN
+then
+	# Convert unix style paths to escaped Windows style paths for Watchman
+	case "$(uname -s)" in
+	MSYS_NT*)
+	  GIT_WORK_TREE="$(cygpath -aw "$PWD" | sed 's,\\,/,g')"
+	  ;;
+	*)
+	  GIT_WORK_TREE="$PWD"
+	  ;;
+	esac
+fi
+
+if test -n "$GIT_PERF_7519_DROP_CACHE"
+then
+	# When using GIT_PERF_7519_DROP_CACHE, GIT_PERF_REPEAT_COUNT must be 1 to
+	# generate valid results. Otherwise the caching that happens for the nth
+	# run will negate the validity of the comparisons.
+	if test "$GIT_PERF_REPEAT_COUNT" -ne 1
+	then
+		echo "warning: Setting GIT_PERF_REPEAT_COUNT=1" >&2
+		GIT_PERF_REPEAT_COUNT=1
+	fi
+fi
+
+test_expect_success "setup for fsmonitor" '
+	# set untrackedCache depending on the environment
+	if test -n "$GIT_PERF_7519_UNTRACKED_CACHE"
+	then
+		git config core.untrackedCache "$GIT_PERF_7519_UNTRACKED_CACHE"
+	else
+		if test_have_prereq UNTRACKED_CACHE
+		then
+			git config core.untrackedCache true
+		else
+			git config core.untrackedCache false
+		fi
+	fi &&
+
+	# set core.splitindex depending on the environment
+	if test -n "$GIT_PERF_7519_SPLIT_INDEX"
+	then
+		git config core.splitIndex "$GIT_PERF_7519_SPLIT_INDEX"
+	fi &&
+
+	# set INTEGRATION_SCRIPT depending on the environment
+	if test -n "$GIT_PERF_7519_FSMONITOR"
+	then
+		INTEGRATION_SCRIPT="$GIT_PERF_7519_FSMONITOR"
+	else
+		#
+		# Choose integration script based on existence of Watchman.
+		# If Watchman exists, watch the work tree and attempt a query.
+		# If everything succeeds, use Watchman integration script,
+		# else fall back to an empty integration script.
+		#
+		mkdir .git/hooks &&
+		if test_have_prereq WATCHMAN
+		then
+			INTEGRATION_SCRIPT=".git/hooks/fsmonitor-watchman" &&
+			cp "$TEST_DIRECTORY/../templates/hooks--fsmonitor-watchman.sample" "$INTEGRATION_SCRIPT" &&
+			watchman watch "$GIT_WORK_TREE" &&
+			watchman watch-list | grep -q -F "$GIT_WORK_TREE"
+		else
+			INTEGRATION_SCRIPT=".git/hooks/fsmonitor-empty" &&
+			write_script "$INTEGRATION_SCRIPT"<<-\EOF
+			EOF
+		fi
+	fi &&
+
+	git config core.fsmonitor "$INTEGRATION_SCRIPT" &&
+	git update-index --fsmonitor
+'
+
+if test -n "$GIT_PERF_7519_DROP_CACHE"; then
+	test-drop-caches
+fi
+
+test_perf "status (fsmonitor=$INTEGRATION_SCRIPT)" '
+	git status
+'
+
+if test -n "$GIT_PERF_7519_DROP_CACHE"; then
+	test-drop-caches
+fi
+
+test_perf "status -uno (fsmonitor=$INTEGRATION_SCRIPT)" '
+	git status -uno
+'
+
+if test -n "$GIT_PERF_7519_DROP_CACHE"; then
+	test-drop-caches
+fi
+
+test_perf "status -uall (fsmonitor=$INTEGRATION_SCRIPT)" '
+	git status -uall
+'
+
+test_expect_success "setup without fsmonitor" '
+	unset INTEGRATION_SCRIPT &&
+	git config --unset core.fsmonitor &&
+	git update-index --no-fsmonitor
+'
+
+if test -n "$GIT_PERF_7519_DROP_CACHE"; then
+	test-drop-caches
+fi
+
+test_perf "status (fsmonitor=$INTEGRATION_SCRIPT)" '
+	git status
+'
+
+if test -n "$GIT_PERF_7519_DROP_CACHE"; then
+	test-drop-caches
+fi
+
+test_perf "status -uno (fsmonitor=$INTEGRATION_SCRIPT)" '
+	git status -uno
+'
+
+if test -n "$GIT_PERF_7519_DROP_CACHE"; then
+	test-drop-caches
+fi
+
+test_perf "status -uall (fsmonitor=$INTEGRATION_SCRIPT)" '
+	git status -uall
+'
+
+if test_have_prereq WATCHMAN
+then
+	watchman watch-del "$GIT_WORK_TREE" >/dev/null 2>&1 &&
+
+	# Work around Watchman bug on Windows where it holds on to handles
+	# preventing the removal of the trash directory
+	watchman shutdown-server >/dev/null 2>&1
+fi
+
+test_done
diff --git a/t/perf/perf-lib.sh b/t/perf/perf-lib.sh
index b50211b259..e4c343a6b7 100644
--- a/t/perf/perf-lib.sh
+++ b/t/perf/perf-lib.sh
@@ -56,12 +56,10 @@ MODERN_GIT=$GIT_BUILD_DIR/bin-wrappers/git
 export MODERN_GIT
 
 perf_results_dir=$TEST_OUTPUT_DIRECTORY/test-results
+test -n "$GIT_PERF_SUBSECTION" && perf_results_dir="$perf_results_dir/$GIT_PERF_SUBSECTION"
 mkdir -p "$perf_results_dir"
 rm -f "$perf_results_dir"/$(basename "$0" .sh).subtests
 
-if test -z "$GIT_PERF_REPEAT_COUNT"; then
-	GIT_PERF_REPEAT_COUNT=3
-fi
 die_if_build_dir_not_repo () {
 	if ! ( cd "$TEST_DIRECTORY/.." &&
 		    git rev-parse --build-dir >/dev/null 2>&1 ); then
diff --git a/t/perf/run b/t/perf/run
index beb4acc0e4..43e4de49ef 100755
--- a/t/perf/run
+++ b/t/perf/run
@@ -2,9 +2,14 @@
 
 case "$1" in
 	--help)
-		echo "usage: $0 [other_git_tree...] [--] [test_scripts]"
+		echo "usage: $0 [--config file] [other_git_tree...] [--] [test_scripts]"
 		exit 0
 		;;
+	--config)
+		shift
+		GIT_PERF_CONFIG_FILE=$(cd "$(dirname "$1")"; pwd)/$(basename "$1")
+		export GIT_PERF_CONFIG_FILE
+		shift ;;
 esac
 
 die () {
@@ -29,8 +34,10 @@ unpack_git_rev () {
 	(cd "$(git rev-parse --show-cdup)" && git archive --format=tar $rev) |
 	(cd build/$rev && tar x)
 }
+
 build_git_rev () {
 	rev=$1
+	name="$2"
 	for config in config.mak config.mak.autogen config.status
 	do
 		if test -e "../../$config"
@@ -38,7 +45,7 @@ build_git_rev () {
 			cp "../../$config" "build/$rev/"
 		fi
 	done
-	echo "=== Building $rev ==="
+	echo "=== Building $rev ($name) ==="
 	(
 		cd build/$rev &&
 		if test -n "$GIT_PERF_MAKE_COMMAND"
@@ -65,7 +72,7 @@ run_dirs_helper () {
 		if [ ! -d build/$rev ]; then
 			unpack_git_rev $rev
 		fi
-		build_git_rev $rev
+		build_git_rev $rev "$mydir"
 		mydir=build/$rev
 	fi
 	if test "$mydir" = .; then
@@ -87,14 +94,78 @@ run_dirs () {
 	done
 }
 
-GIT_PERF_AGGREGATING_LATER=t
-export GIT_PERF_AGGREGATING_LATER
+get_subsections () {
+	section="$1"
+	test -z "$GIT_PERF_CONFIG_FILE" && return
+	git config -f "$GIT_PERF_CONFIG_FILE" --name-only --get-regex "$section\..*\.[^.]+" |
+	sed -e "s/$section\.\(.*\)\..*/\1/" | sort | uniq
+}
+
+get_var_from_env_or_config () {
+	env_var="$1"
+	conf_sec="$2"
+	conf_var="$3"
+	# $4 can be set to a default value
+
+	# Do nothing if the env variable is already set
+	eval "test -z \"\${$env_var+x}\"" || return
+
+	test -z "$GIT_PERF_CONFIG_FILE" && return
+
+	# Check if the variable is in the config file
+	if test -n "$GIT_PERF_SUBSECTION"
+	then
+		var="$conf_sec.$GIT_PERF_SUBSECTION.$conf_var"
+		conf_value=$(git config -f "$GIT_PERF_CONFIG_FILE" "$var") &&
+		eval "$env_var=\"$conf_value\"" && return
+	fi
+	var="$conf_sec.$conf_var"
+	conf_value=$(git config -f "$GIT_PERF_CONFIG_FILE" "$var") &&
+	eval "$env_var=\"$conf_value\"" && return
+
+	test -n "${4+x}" && eval "$env_var=\"$4\""
+}
+
+run_subsection () {
+	get_var_from_env_or_config "GIT_PERF_REPEAT_COUNT" "perf" "repeatCount" 3
+	export GIT_PERF_REPEAT_COUNT
+
+	get_var_from_env_or_config "GIT_PERF_DIRS_OR_REVS" "perf" "dirsOrRevs"
+	set -- $GIT_PERF_DIRS_OR_REVS "$@"
+
+	get_var_from_env_or_config "GIT_PERF_MAKE_COMMAND" "perf" "makeCommand"
+	get_var_from_env_or_config "GIT_PERF_MAKE_OPTS" "perf" "makeOpts"
+
+	GIT_PERF_AGGREGATING_LATER=t
+	export GIT_PERF_AGGREGATING_LATER
+
+	if test $# = 0 -o "$1" = -- -o -f "$1"; then
+		set -- . "$@"
+	fi
+
+	run_dirs "$@"
+	./aggregate.perl "$@"
+}
 
 cd "$(dirname $0)"
 . ../../GIT-BUILD-OPTIONS
 
-if test $# = 0 -o "$1" = -- -o -f "$1"; then
-	set -- . "$@"
+mkdir -p test-results
+get_subsections "perf" >test-results/run_subsections.names
+
+if test $(wc -l <test-results/run_subsections.names) -eq 0
+then
+	(
+		run_subsection "$@"
+	)
+else
+	while read -r subsec
+	do
+		(
+			GIT_PERF_SUBSECTION="$subsec"
+			export GIT_PERF_SUBSECTION
+			echo "======== Run for subsection '$GIT_PERF_SUBSECTION' ========"
+			run_subsection "$@"
+		)
+	done <test-results/run_subsections.names
 fi
-run_dirs "$@"
-./aggregate.perl "$@"