[PATCH v2 3/3] fsmonitor: add perf test for git diff HEAD

From: Nipunn Koorapati via GitGitGadget <gitgitgadget@gmail.com>
Date: Mar 17, 2021, 21:22 UTC
Message-ID: <f9d0fd594fdb515e3a3cd4bd14b8b09532ccc483.1616016143.git.gitgitgadget@gmail.com>
In-Reply-To: <pull.903.v2.git.1616016143.gitgitgadget@gmail.com>

From: Nipunn Koorapati <nipunn@dropbox.com>

Update the xargs call so that if your large repo contains symlinks, test-tool chmtime failure does not end the script.

On Linux Test this tree upstream/master --------------------------------------------------------------------------------------------------------- 7519.4: status (fsmonitor=fsmonitor-watchman) 0.52(0.43+0.10) 0.53(0.49+0.05) +1.9% 7519.5: status -uno (fsmonitor=fsmonitor-watchman) 0.21(0.15+0.07) 0.22(0.13+0.09) +4.8% 7519.6: status -uall (fsmonitor=fsmonitor-watchman) 1.65(0.93+0.71) 1.69(1.03+0.65) +2.4% 7519.7: status (dirty) (fsmonitor=fsmonitor-watchman) 11.99(11.34+1.58) 11.95(11.02+1.79) -0.3% 7519.8: diff (fsmonitor=fsmonitor-watchman) 0.25(0.17+0.26) 0.25(0.18+0.26) +0.0% 7519.9: diff HEAD (fsmonitor=fsmonitor-watchman) 0.39(0.25+0.34) 0.89(0.35+0.74) +128.2% 7519.10: diff -- 0_files (fsmonitor=fsmonitor-watchman) 0.16(0.13+0.04) 0.16(0.12+0.05) +0.0% 7519.11: diff -- 10_files (fsmonitor=fsmonitor-watchman) 0.16(0.12+0.05) 0.16(0.12+0.05) +0.0% 7519.12: diff -- 100_files (fsmonitor=fsmonitor-watchman) 0.16(0.12+0.05) 0.16(0.12+0.05) +0.0% 7519.13: diff -- 1000_files (fsmonitor=fsmonitor-watchman) 0.16(0.11+0.06) 0.16(0.12+0.05) +0.0% 7519.14: diff -- 10000_files (fsmonitor=fsmonitor-watchman) 0.18(0.13+0.06) 0.17(0.10+0.08) -5.6% 7519.15: add (fsmonitor=fsmonitor-watchman) 2.25(1.53+0.68) 2.25(1.47+0.74) +0.0% 7519.18: status (fsmonitor=disabled) 0.88(0.73+1.03) 0.89(0.67+1.08) +1.1% 7519.19: status -uno (fsmonitor=disabled) 0.45(0.43+0.89) 0.45(0.34+0.98) +0.0% 7519.20: status -uall (fsmonitor=disabled) 1.88(1.16+1.58) 1.88(1.22+1.51) +0.0% 7519.21: status (dirty) (fsmonitor=disabled) 7.53(7.05+2.11) 7.53(6.98+2.04) +0.0% 7519.22: diff (fsmonitor=disabled) 0.42(0.37+0.92) 0.42(0.38+0.91) +0.0% 7519.23: diff HEAD (fsmonitor=disabled) 0.44(0.41+0.90) 0.44(0.40+0.91) +0.0% 7519.24: diff -- 0_files (fsmonitor=disabled) 0.13(0.09+0.05) 0.13(0.09+0.05) +0.0% 7519.25: diff -- 10_files (fsmonitor=disabled) 0.13(0.10+0.04) 0.13(0.10+0.04) +0.0% 7519.26: diff -- 100_files (fsmonitor=disabled) 0.13(0.09+0.05) 0.13(0.10+0.04) +0.0% 7519.27: diff -- 1000_files (fsmonitor=disabled) 0.13(0.09+0.06) 0.13(0.09+0.05) +0.0% 7519.28: diff -- 10000_files (fsmonitor=disabled) 0.14(0.11+0.05) 0.14(0.10+0.05) +0.0% 7519.29: add (fsmonitor=disabled) 2.43(1.61+1.64) 2.43(1.69+1.57) +0.0%

On linux (2.29.2 vs w/ this patch):
nipunn@nipunn-dbx:~/src/server3$ strace -f -c git diff 2>&1 | grep lstat
  0.04    0.000063           3        20         6 lstat
nipunn@nipunn-dbx:~/src/server3$ strace -f -c git diff HEAD 2>&1 | grep lstat
 94.98    5.242262          10    523783        13 lstat
nipunn@nipunn-dbx:~/src/server3$ strace -f -c ../git/bin-wrappers/git diff 2>&1 | grep lstat
  0.38    0.000032           5         7         3 lstat
nipunn@nipunn-dbx:~/src/server3$ strace -f -c ../git/bin-wrappers/git diff HEAD 2>&1 | grep lstat
 99.44    0.741892           9     81634        10 lstat

On mac (2.29.2 vs w/ this patch): nipunn-mbp:server nipunn$ sudo dtruss -L -f -c git diff 2>&1 | grep "^lstat64 " lstat64 8 nipunn-mbp:server nipunn$ sudo dtruss -L -f -c git diff HEAD 2>&1 | grep "^lstat64 " lstat64 120242 nipunn-mbp:server nipunn$ sudo dtruss -L -f -c ../git/bin-wrappers/git diff 2>&1 | grep "^lstat64 " lstat64 4 nipunn-mbp:server nipunn$ sudo dtruss -L -f -c ../git/bin-wrappers/git diff HEAD 2>&1 | grep "^lstat64 " lstat64 4497

There are still a bunch of lstats - on directories, but not every file. Progress!

Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com>
---
 t/helper/test-chmtime.c   | 4 ++--
 t/perf/p7519-fsmonitor.sh | 4 ++++
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/t/helper/test-chmtime.c b/t/helper/test-chmtime.c
index aa22af48c2a6..524b55ca496c 100644
--- a/t/helper/test-chmtime.c
+++ b/t/helper/test-chmtime.c
@@ -109,9 +109,9 @@ int cmd__chmtime(int argc, const char **argv)
 		uintmax_t mtime;
 
 		if (stat(argv[i], &sb) < 0) {
-			fprintf(stderr, "Failed to stat %s: %s\n",
+			fprintf(stderr, "Failed to stat %s: %s. Skipping\n",
 			        argv[i], strerror(errno));
-			return 1;
+			continue;
 		}
 
 #ifdef GIT_WINDOWS_NATIVE
diff --git a/t/perf/p7519-fsmonitor.sh b/t/perf/p7519-fsmonitor.sh
index b657564aed60..5eb5044a103c 100755
--- a/t/perf/p7519-fsmonitor.sh
+++ b/t/perf/p7519-fsmonitor.sh
@@ -216,6 +216,10 @@ test_fsmonitor_suite() {
 		git diff
 	'
 
+	test_perf_w_drop_caches "diff HEAD ($DESC)" '
+		git diff HEAD
+	'
+
 	test_perf_w_drop_caches "diff -- 0_files ($DESC)" '
 		git diff -- 1_file
 	'

-- 
gitgitgadget