8343340: Swapping checking do not work for MetricsMemoryTester failcount

Backport-of: 7e068cc8d572e61cf2f4203f66fe0175a541209d

Author: SendaoYan

test/jdk/jdk/internal/platform/docker/MetricsMemoryTester.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2025, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -70,7 +70,7 @@ private static void testMemoryFailCount() {
 
         // We need swap to execute this test or will SEGV
         if (memAndSwapLimit <= memLimit) {
-            System.out.println("No swap memory limits, test case skipped");
+            System.out.println("No swap memory limits. Ignoring test!");
         } else {
             long count = Metrics.systemMetrics().getMemoryFailCount();
 

test/jdk/jdk/internal/platform/docker/TestDockerMemoryMetrics.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2025, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -27,6 +27,7 @@
 import jdk.test.lib.containers.docker.DockerRunOptions;
 import jdk.test.lib.containers.docker.DockerTestUtils;
 import jdk.test.lib.process.OutputAnalyzer;
+import jtreg.SkippedException;
 
 /*
  * @test
@@ -112,18 +113,22 @@ private static void testMemoryFailCount(String value) throws Exception {
 
         // Check whether swapping really works for this test
         // On some systems there is no swap space enabled. And running
-        // 'java -Xms{mem-limit} -Xmx{mem-limit} -version' would fail due to swap space size being 0.
+        // 'java -Xms{mem-limit} -Xmx{mem-limit} -XX:+AlwaysPreTouch -version'
+        // would fail due to swap space size being 0. Note that when swap is
+        // properly enabled on the system the container gets the same amount
+        // of swap as is configured for memory. Thus, 2x{mem-limit} is the actual
+        // memory and swap bound for this pre-test.
         DockerRunOptions preOpts =
                 new DockerRunOptions(imageName, "/jdk/bin/java", "-version");
         preOpts.addDockerOpts("--volume", Utils.TEST_CLASSES + ":/test-classes/")
                 .addDockerOpts("--memory=" + value)
+                .addJavaOpts("-XX:+AlwaysPreTouch")
                 .addJavaOpts("-Xms" + value)
                 .addJavaOpts("-Xmx" + value);
         OutputAnalyzer oa = DockerTestUtils.dockerRunJava(preOpts);
         String output = oa.getOutput();
         if (!output.contains("version")) {
-            System.out.println("Swapping doesn't work for this test.");
-            return;
+            throw new SkippedException("Swapping doesn't work for this test.");
         }
 
         DockerRunOptions opts =
@@ -137,8 +142,7 @@ private static void testMemoryFailCount(String value) throws Exception {
         oa = DockerTestUtils.dockerRunJava(opts);
         output = oa.getOutput();
         if (output.contains("Ignoring test")) {
-            System.out.println("Ignored by the tester");
-            return;
+            throw new SkippedException("Ignored by the tester");
         }
         oa.shouldHaveExitValue(0).shouldContain("TEST PASSED!!!");
     }