tests: avoid unwarranted failure in a netbsd 8.1 VM

* tests/mb-non-UTF8-perf-Fw: Run twice, to avoid first-read penalty.
Reported by Nelson H.F. Beebe.

1 files changed, 7 insertions, 0 deletions

diff --git a/tests/mb-non-UTF8-perf-Fw b/tests/mb-non-UTF8-perf-Fw
index 01098ab8..24309a10 100755
--- a/tests/mb-non-UTF8-perf-Fw
+++ b/tests/mb-non-UTF8-perf-Fw
@@ -25,6 +25,13 @@ require_JP_EUC_locale_
 
 yes 00 | head -10000000 > in || framework_failure_
 
+# Since we're using an absolute timeout below and want to avoid any initial
+# disk read performance penalty, run first with a large timeout and no error
+# test to prime any cache. Prompted by a report of test failure on a netbsd8.1
+# VM whereby the first run would take 2.5 MINUTES, yet the second would complete
+# in just half a second.
+timeout 500 grep -Fw 0 in
+
 # Before fixing the regression, this would have taken minutes.
 # With the fix, it typically completes in well under one second.
 returns_ 1 timeout 30 grep -Fw 0 in || fail=1