p7300: add performance tests for clean

diff --git a/t/perf/p5310-pack-bitmaps.sh b/t/perf/p5310-pack-bitmaps.sh
index 8c6ae4567c68a10f83d75ae973d1a9f5a1258ca2..f8ed8573b728e82f7f4afaee677758b736048ebe 100755 (executable)
--- a/t/perf/p5310-pack-bitmaps.sh
+++ b/t/perf/p5310-pack-bitmaps.sh
@@ -8,8 +8,12 @@ test_perf_large_repo
 # note that we do everything through config,
 # since we want to be able to compare bitmap-aware
 # git versus non-bitmap git
+#
+# We intentionally use the deprecated pack.writebitmaps
+# config so that we can test against older versions of git.
 test_expect_success 'setup bitmap config' '
-       git config pack.writebitmaps true
+       git config pack.writebitmaps true &&
+       git config pack.writebitmaphashcache true
 '
 
 test_perf 'repack to disk' '