4 files changed, 86 insertions, 21 deletions
diff --git a/t/perf/.gitignore b/t/perf/.gitignore
index 982eb8e3a9..72f5d0d314 100644
--- a/t/perf/.gitignore
+++ b/t/perf/.gitignore
@@ -1,3 +1,4 @@
 /build/
 /test-results/
+/test-trace/
 /trash directory*/
diff --git a/t/perf/Makefile b/t/perf/Makefile
index fcb0e8865e..2465770a78 100644
--- a/t/perf/Makefile
+++ b/t/perf/Makefile
@@ -7,10 +7,10 @@ perf: pre-clean
 	./run
 
 pre-clean:
-	rm -rf test-results
+	rm -rf test-results test-trace
 
 clean:
-	rm -rf build "trash directory".* test-results
+	rm -rf build "trash directory".* test-results test-trace
 
 test-lint:
 	$(MAKE) -C .. test-lint
diff --git a/t/perf/p7519-fsmonitor.sh b/t/perf/p7519-fsmonitor.sh
index 1e20a184c7..b657564aed 100755
--- a/t/perf/p7519-fsmonitor.sh
+++ b/t/perf/p7519-fsmonitor.sh
@@ -32,6 +32,8 @@ test_description="Test core.fsmonitor"
 #
 # GIT_PERF_7519_DROP_CACHE: if set, the OS caches are dropped between tests
 #
+# GIT_PERF_7519_TRACE: if set, enable trace logging during the test.
+#   Trace logs will be grouped by fsmonitor provider.
 
 test_perf_large_repo
 test_checkout_worktree
@@ -70,6 +72,32 @@ then
 	fi
 fi
 
+trace_start() {
+	if test -n "$GIT_PERF_7519_TRACE"
+	then
+		name="$1"
+		TEST_TRACE_DIR="$TEST_OUTPUT_DIRECTORY/test-trace/p7519/"
+		echo "Writing trace logging to $TEST_TRACE_DIR"
+
+		mkdir -p "$TEST_TRACE_DIR"
+
+		# Start Trace2 logging and any other GIT_TRACE_* logs that you
+		# want for this named test case.
+
+		GIT_TRACE2_PERF="$TEST_TRACE_DIR/$name.trace2perf"
+		export GIT_TRACE2_PERF
+
+		>"$GIT_TRACE2_PERF"
+	fi
+}
+
+trace_stop() {
+	if test -n "$GIT_PERF_7519_TRACE"
+	then
+		unset GIT_TRACE2_PERF
+	fi
+}
+
 test_expect_success "one time repo setup" '
 	# set untrackedCache depending on the environment
 	if test -n "$GIT_PERF_7519_UNTRACKED_CACHE"
@@ -101,7 +129,7 @@ test_expect_success "one time repo setup" '
 	# If Watchman exists, watch the work tree and attempt a query.
 	if test_have_prereq WATCHMAN; then
 		watchman watch "$GIT_WORK_TREE" &&
-		watchman watch-list | grep -q -F "$GIT_WORK_TREE"
+		watchman watch-list | grep -q -F "p7519-fsmonitor"
 	fi
 '
 
@@ -169,8 +197,18 @@ test_fsmonitor_suite() {
 		git status -uall
 	'
 
+	# Update the mtimes on upto 100k files to make status think
+	# that they are dirty.  For simplicity, omit any files with
+	# LFs (i.e. anything that ls-files thinks it needs to dquote).
+	# Then fully backslash-quote the paths to capture any
+	# whitespace so that they pass thru xargs properly.
+	#
 	test_perf_w_drop_caches "status (dirty) ($DESC)" '
-		git ls-files | head -100000 | xargs -d "\n" touch -h &&
+		git ls-files | \
+			head -100000 | \
+			grep -v \" | \
+			sed '\''s/\(.\)/\\\1/g'\'' | \
+			xargs test-tool chmtime -300 &&
 		git status
 	'
 
@@ -203,6 +241,12 @@ test_fsmonitor_suite() {
 	'
 }
 
+#
+# Run a full set of perf tests using each Hook-based fsmonitor provider,
+# such as Watchman.
+#
+
+trace_start fsmonitor-watchman
 if test -n "$GIT_PERF_7519_FSMONITOR"; then
 	for INTEGRATION_PATH in $GIT_PERF_7519_FSMONITOR; do
 		test_expect_success "setup for fsmonitor $INTEGRATION_PATH" 'setup_for_fsmonitor'
@@ -213,14 +257,6 @@ else
 	test_fsmonitor_suite
 fi
 
-test_expect_success "setup without fsmonitor" '
-	unset INTEGRATION_SCRIPT &&
-	git config --unset core.fsmonitor &&
-	git update-index --no-fsmonitor
-'
-
-test_fsmonitor_suite
-
 if test_have_prereq WATCHMAN
 then
 	watchman watch-del "$GIT_WORK_TREE" >/dev/null 2>&1 &&
@@ -229,5 +265,20 @@ then
 	# preventing the removal of the trash directory
 	watchman shutdown-server >/dev/null 2>&1
 fi
+trace_stop
+
+#
+# Run a full set of perf tests with the fsmonitor feature disabled.
+#
+
+trace_start fsmonitor-disabled
+test_expect_success "setup without fsmonitor" '
+	unset INTEGRATION_SCRIPT &&
+	git config --unset core.fsmonitor &&
+	git update-index --no-fsmonitor
+'
+
+test_fsmonitor_suite
+trace_stop
 
 test_done
diff --git a/t/perf/perf-lib.sh b/t/perf/perf-lib.sh
index e385c6896f..601d9f67dd 100644
--- a/t/perf/perf-lib.sh
+++ b/t/perf/perf-lib.sh
@@ -70,6 +70,19 @@ test_perf_do_repo_symlink_config_ () {
 	test_have_prereq SYMLINKS || git config core.symlinks false
 }
 
+test_perf_copy_repo_contents () {
+	for stuff in "$1"/*
+	do
+		case "$stuff" in
+		*/objects|*/hooks|*/config|*/commondir|*/gitdir|*/worktrees)
+			;;
+		*)
+			cp -R "$stuff" "$repo/.git/" || exit 1
+			;;
+		esac
+	done
+}
+
 test_perf_create_repo_from () {
 	test "$#" = 2 ||
 	BUG "not 2 parameters to test-create-repo"
@@ -77,20 +90,20 @@ test_perf_create_repo_from () {
 	source="$2"
 	source_git="$("$MODERN_GIT" -C "$source" rev-parse --git-dir)"
 	objects_dir="$("$MODERN_GIT" -C "$source" rev-parse --git-path objects)"
+	common_dir="$("$MODERN_GIT" -C "$source" rev-parse --git-common-dir)"
 	mkdir -p "$repo/.git"
 	(
 		cd "$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|*/commondir)
-					;;
-				*)
-					cp -R "$stuff" "$repo/.git/" || exit 1
-					;;
-			esac
-		done
+
+		# common_dir must come first here, since we want source_git to
+		# take precedence and overwrite any overlapping files
+		test_perf_copy_repo_contents "$common_dir"
+		if test "$source_git" != "$common_dir"
+		then
+			test_perf_copy_repo_contents "$source_git"
+		fi
 	) &&
 	(
 		cd "$repo" &&