8340419: ZGC: Create an UseLargePages adaptation of TestAllocateHeapAt.java

Reviewed-by: stefank, sjohanss, jsikstro

Author: xmas92

test/hotspot/jtreg/gc/z/TestAllocateHeapAtWithHugeTLBFS.java

@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 2024, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package gc.z;
+
+/*
+ * @test TestAllocateHeapAtWithHugeTLBFS
+ * @requires vm.gc.ZGenerational & os.family == "linux"
+ * @summary Test ZGC with -XX:AllocateHeapAt and -XX:+UseLargePages
+ * @library /test/lib
+ * @run driver gc.z.TestAllocateHeapAtWithHugeTLBFS true
+ * @run driver gc.z.TestAllocateHeapAtWithHugeTLBFS false
+ */
+
+import jdk.test.lib.process.ProcessTools;
+import jtreg.SkippedException;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.nio.file.Path;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.util.Scanner;
+
+public class TestAllocateHeapAtWithHugeTLBFS {
+    static String find_hugetlbfs_mountpoint() {
+        Pattern pat = Pattern.compile("\\d+ \\d+ \\d+:\\d+ \\S+ (\\S+) [^-]*- hugetlbfs (.+)");
+        try (Scanner scanner = new Scanner(new File("/proc/self/mountinfo"))) {
+            while (scanner.hasNextLine()) {
+                final Matcher mat = pat.matcher(scanner.nextLine());
+                if (mat.matches() && mat.group(2).contains("pagesize=2M")) {
+                    final Path path = Paths.get(mat.group(1));
+                    if (Files.isReadable(path) &&
+                        Files.isWritable(path) &&
+                        Files.isExecutable(path)) {
+                        // Found a usable mount point.
+                        return path.toString();
+                    }
+                }
+            }
+        } catch (FileNotFoundException e) {
+            System.out.println("Could not open /proc/self/mountinfo");
+        }
+        return null;
+    }
+    public static void main(String[] args) throws Exception {
+        final boolean exists = Boolean.parseBoolean(args[0]);
+        final String directory = exists ? find_hugetlbfs_mountpoint()
+                                        : "non-existing-directory";
+        if (directory == null) {
+            throw new SkippedException("No valid hugetlbfs mount point found");
+        }
+        final String heapBackingFile = "Heap Backing File: " + directory;
+        final String failedToCreateFile = "Failed to create file " + directory;
+
+        ProcessTools.executeTestJava(
+            "-XX:+UseZGC",
+            "-XX:+ZGenerational",
+            "-Xlog:gc*",
+            "-Xms32M",
+            "-Xmx32M",
+            "-XX:+UseLargePages",
+            "-XX:AllocateHeapAt=" + directory,
+            "-version")
+                .shouldContain(exists ? heapBackingFile : failedToCreateFile)
+                .shouldNotContain(exists ? failedToCreateFile : heapBackingFile)
+                .shouldHaveExitValue(exists ? 0 : 1);
+    }
+}