Merge branch 'jh/memihash-opt' into maint

perf-test update.

* jh/memihash-opt:
  p0004: don't error out if test repo is too small
  p0004: don't abort if multi-threaded is too slow
  p0004: use test_perf
  p0004: avoid using pipes
  p0004: simplify calls of test-lazy-init-name-hash

t/perf/p0004-lazy-init-name-hash.sh

@@ -7,13 +7,50 @@ test_perf_large_repo
 test_checkout_worktree
 
 test_expect_success 'verify both methods build the same hashmaps' '
-	$GIT_BUILD_DIR/t/helper/test-lazy-init-name-hash$X --dump --single | sort >out.single &&
-	$GIT_BUILD_DIR/t/helper/test-lazy-init-name-hash$X --dump --multi  | sort >out.multi  &&
-	test_cmp out.single out.multi
+	test-lazy-init-name-hash --dump --single >out.single &&
+	if test-lazy-init-name-hash --dump --multi >out.multi
+	then
+		test_set_prereq REPO_BIG_ENOUGH_FOR_MULTI &&
+		sort <out.single >sorted.single &&
+		sort <out.multi >sorted.multi &&
+		test_cmp sorted.single sorted.multi
+	fi
 '
 
-test_expect_success 'multithreaded should be faster' '
-	$GIT_BUILD_DIR/t/helper/test-lazy-init-name-hash$X --perf >out.perf
+test_expect_success 'calibrate' '
+	entries=$(wc -l <out.single) &&
+
+	case $entries in
+	?) count=1000000 ;;
+	??) count=100000 ;;
+	???) count=10000 ;;
+	????) count=1000 ;;
+	?????) count=100 ;;
+	??????) count=10 ;;
+	*) count=1 ;;
+	esac &&
+	export count &&
+
+	case $entries in
+	1) entries_desc="1 entry" ;;
+	*) entries_desc="$entries entries" ;;
+	esac &&
+
+	case $count in
+	1) count_desc="1 round" ;;
+	*) count_desc="$count rounds" ;;
+	esac &&
+
+	desc="$entries_desc, $count_desc" &&
+	export desc
 '
 
+test_perf "single-threaded, $desc" "
+	test-lazy-init-name-hash --single --count=$count
+"
+
+test_perf REPO_BIG_ENOUGH_FOR_MULTI "multi-threaded, $desc" "
+	test-lazy-init-name-hash --multi --count=$count
+"
+
 test_done