7072527: CMS: JMM GC counters overcount in some cases
Summary: Avoid overcounting when CMS has concurrent mode failure.
Reviewed-by: ysr
Contributed-by: rednaxelafx@gmail.com
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp Tue Jul 12 16:32:25 2011 -0700
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp Tue Aug 02 14:37:35 2011 +0100
@@ -2025,9 +2025,6 @@
_intra_sweep_estimate.padded_average());
}
- {
- TraceCMSMemoryManagerStats tmms(gch->gc_cause());
- }
GenMarkSweep::invoke_at_safepoint(_cmsGen->level(),
ref_processor(), clear_all_soft_refs);
#ifdef ASSERT
@@ -9345,15 +9342,3 @@
}
}
-// when bailing out of cms in concurrent mode failure
-TraceCMSMemoryManagerStats::TraceCMSMemoryManagerStats(GCCause::Cause cause): TraceMemoryManagerStats() {
- initialize(true /* fullGC */ ,
- cause /* cause of the GC */,
- true /* recordGCBeginTime */,
- true /* recordPreGCUsage */,
- true /* recordPeakUsage */,
- true /* recordPostGCusage */,
- true /* recordAccumulatedGCTime */,
- true /* recordGCEndTime */,
- true /* countCollection */ );
-}
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp Tue Jul 12 16:32:25 2011 -0700
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp Tue Aug 02 14:37:35 2011 +0100
@@ -1900,7 +1900,6 @@
public:
TraceCMSMemoryManagerStats(CMSCollector::CollectorState phase, GCCause::Cause cause);
- TraceCMSMemoryManagerStats(GCCause::Cause cause);
};
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/gc/7072527/TestFullGCCount.java Tue Aug 02 14:37:35 2011 +0100
@@ -0,0 +1,95 @@
+/*
+ * Copyright (c) 2011, 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.
+ */
+
+/*
+ * @test TestFullGCount.java
+ * @bug 7072527
+ * @summary CMS: JMM GC counters overcount in some cases
+ * @run main/othervm -XX:+UseConcMarkSweepGC TestFullGCCount
+ *
+ */
+import java.util.*;
+import java.lang.management.*;
+
+public class TestFullGCCount {
+
+ public String collectorName = "ConcurrentMarkSweep";
+
+ public static void main(String [] args) {
+
+ TestFullGCCount t = null;
+ if (args.length==2) {
+ t = new TestFullGCCount(args[0], args[1]);
+ } else {
+ t = new TestFullGCCount();
+ }
+ System.out.println("Monitoring collector: " + t.collectorName);
+ t.run();
+ }
+
+ public TestFullGCCount(String pool, String collector) {
+ collectorName = collector;
+ }
+
+ public TestFullGCCount() {
+ }
+
+ public void run() {
+ int count = 0;
+ int iterations = 20;
+ long counts[] = new long[iterations];
+ boolean diffAlways2 = true; // assume we will fail
+
+ for (int i=0; i<iterations; i++) {
+ System.gc();
+ counts[i] = getCollectionCount();
+ if (i>0) {
+ if (counts[i] - counts[i-1] != 2) {
+ diffAlways2 = false;
+ }
+ }
+ }
+ if (diffAlways2) {
+ throw new RuntimeException("FAILED: System.gc must be incrementing count twice.");
+ }
+ System.out.println("Passed.");
+ }
+
+ private long getCollectionCount() {
+ long count = 0;
+ List<MemoryPoolMXBean> pools = ManagementFactory.getMemoryPoolMXBeans();
+ List<GarbageCollectorMXBean> collectors = ManagementFactory.getGarbageCollectorMXBeans();
+ for (int i=0; i<collectors.size(); i++) {
+ GarbageCollectorMXBean collector = collectors.get(i);
+ String name = collector.getName();
+ if (name.contains(collectorName)) {
+ System.out.println(name + ": collection count = "
+ + collector.getCollectionCount());
+ count = collector.getCollectionCount();
+ }
+ }
+ return count;
+ }
+
+}
+