8026752: Cancel MetaspaceGC request for a CMS concurrent collection after GC
Reviewed-by: sjohanss, sangheki
--- a/hotspot/src/share/vm/gc/cms/concurrentMarkSweepGeneration.cpp Fri Jun 10 20:28:46 2016 +0200
+++ b/hotspot/src/share/vm/gc/cms/concurrentMarkSweepGeneration.cpp Fri Jun 10 09:22:09 2016 -0700
@@ -1605,6 +1605,9 @@
_inter_sweep_timer.reset();
_inter_sweep_timer.start();
+ // No longer a need to do a concurrent collection for Metaspace.
+ MetaspaceGC::set_should_concurrent_collect(false);
+
gch->post_full_gc_dump(gc_timer);
gc_timer->register_gc_end();
--- a/hotspot/src/share/vm/prims/whitebox.cpp Fri Jun 10 20:28:46 2016 +0200
+++ b/hotspot/src/share/vm/prims/whitebox.cpp Fri Jun 10 09:22:09 2016 -0700
@@ -1433,6 +1433,10 @@
return (jlong) MetaspaceGC::capacity_until_GC();
WB_END
+WB_ENTRY(jboolean, WB_MetaspaceShouldConcurrentCollect(JNIEnv* env, jobject wb))
+ return MetaspaceGC::should_concurrent_collect();
+WB_END
+
WB_ENTRY(void, WB_AssertMatchingSafepointCalls(JNIEnv* env, jobject o, jboolean mutexSafepointValue, jboolean attemptedNoSafepointValue))
Monitor::SafepointCheckRequired sfpt_check_required = mutexSafepointValue ?
@@ -1813,6 +1817,7 @@
CC"(Ljava/lang/ClassLoader;JJ)V", (void*)&WB_FreeMetaspace },
{CC"incMetaspaceCapacityUntilGC", CC"(J)J", (void*)&WB_IncMetaspaceCapacityUntilGC },
{CC"metaspaceCapacityUntilGC", CC"()J", (void*)&WB_MetaspaceCapacityUntilGC },
+ {CC"metaspaceShouldConcurrentCollect", CC"()Z", (void*)&WB_MetaspaceShouldConcurrentCollect },
{CC"getCPUFeatures", CC"()Ljava/lang/String;", (void*)&WB_GetCPUFeatures },
{CC"getNMethod0", CC"(Ljava/lang/reflect/Executable;Z)[Ljava/lang/Object;",
(void*)&WB_GetNMethod },
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/gc/metaspace/TestMetaspaceCMSCancel.java Fri Jun 10 09:22:09 2016 -0700
@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2016, 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.
+ */
+import jdk.test.lib.process.ProcessTools;
+import jdk.test.lib.process.OutputAnalyzer;
+import jdk.test.lib.Asserts;
+import sun.hotspot.WhiteBox;
+
+/* @test TestMetaspaceCMSCancel
+ * @bug 8026752
+ * @summary Tests cancel of CMS concurrent cycle for Metaspace after a full GC
+ * @library /testlibrary /test/lib /test/lib/share/classes
+ * @modules java.base/jdk.internal.misc
+ * @build TestMetaspaceCMSCancel
+ * @run main ClassFileInstaller sun.hotspot.WhiteBox
+ * @run main/othervm TestMetaspaceCMSCancel
+ */
+
+
+public class TestMetaspaceCMSCancel {
+
+ public static void main(String[] args) throws Exception {
+ // Set a small MetaspaceSize so that a CMS concurrent collection will be
+ // scheduled. Set CMSWaitDuration to 5s so that the concurrent collection
+ // start may be delayed. It does not guarantee 5s before the start of the
+ // concurrent collection but does increase the probability that it will
+ // be started later. System.gc() is used to invoke a full collection. Set
+ // ExplicitGCInvokesConcurrent to off so it is a STW collection.
+ ProcessBuilder pb = ProcessTools.createJavaProcessBuilder("-Xbootclasspath/a:.",
+ "-XX:+UnlockDiagnosticVMOptions",
+ "-XX:+WhiteBoxAPI",
+ "-XX:+UseConcMarkSweepGC",
+ "-XX:MetaspaceSize=2m",
+ "-XX:CMSWaitDuration=5000",
+ "-XX:-ExplicitGCInvokesConcurrent",
+ "-Xlog:gc*=debug",
+ MetaspaceGCTest.class.getName());
+
+ OutputAnalyzer output = new OutputAnalyzer(pb.start());
+ output.shouldNotContain("Concurrent Reset");
+ output.shouldHaveExitValue(0);
+ }
+
+ static class MetaspaceGCTest {
+ public static void main(String [] args) {
+ WhiteBox wb = WhiteBox.getWhiteBox();
+ System.gc();
+ Asserts.assertFalse(wb.metaspaceShouldConcurrentCollect());
+ }
+ }
+}