From 9e8322bcfc391fc8afe151a5e95e766901964bd3 Mon Sep 17 00:00:00 2001
From: duke <duke@openjdk.org>
Date: Wed, 24 Aug 2022 05:46:04 +0000
Subject: [PATCH] Backport 444a0d98ac06ab043e3b11281234fd515abff302

---
 .../test/lib/containers/cgroup/MetricsTesterCgroupV2.java    | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/test/lib/jdk/test/lib/containers/cgroup/MetricsTesterCgroupV2.java b/test/lib/jdk/test/lib/containers/cgroup/MetricsTesterCgroupV2.java
index 25d6c73cbb5..a3723e2eda2 100644
--- a/test/lib/jdk/test/lib/containers/cgroup/MetricsTesterCgroupV2.java
+++ b/test/lib/jdk/test/lib/containers/cgroup/MetricsTesterCgroupV2.java
@@ -121,6 +121,11 @@ private long getLongValueEntryFromFile(String file, String metric) {
         Path filePath = Paths.get(UNIFIED.getPath(), file);
         try {
             String strVal = Files.lines(filePath).filter(l -> l.startsWith(metric)).collect(Collectors.joining());
+            if (strVal.isEmpty()) {
+                // sometimes the match for the metric does not exist, e.g. cpu.stat's nr_periods iff the controller
+                // is not enabled
+                return UNLIMITED;
+            }
             String[] keyValues = strVal.split("\\s+");
             String value = keyValues[1];
             return convertStringToLong(value);