# HG changeset patch
# User brutisso
# Date 1321858054 -3600
# Node ID 7663e46f3a544fd940a4ac342a9fc7f5be4a73a4
# Parent  0cfe4d79060c6eb11280e3d64a6ef3aa192249a5
7110718: -XX:MarkSweepAlwaysCompactCount=0 crashes the JVM
Summary: Interpret MarkSweepAlwaysCompactCount < 1 as never do full compaction
Reviewed-by: ysr, tonyp, jmasa, johnc

diff -r 0cfe4d79060c -r 7663e46f3a54 hotspot/src/share/vm/gc_implementation/parallelScavenge/psMarkSweepDecorator.cpp
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psMarkSweepDecorator.cpp	Fri Nov 18 12:52:27 2011 -0500
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psMarkSweepDecorator.cpp	Mon Nov 21 07:47:34 2011 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 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
@@ -96,7 +96,8 @@
    * by the MarkSweepAlwaysCompactCount parameter. This is a significant
    * performance improvement!
    */
-  bool skip_dead = ((PSMarkSweep::total_invocations() % MarkSweepAlwaysCompactCount) != 0);
+  bool skip_dead = (MarkSweepAlwaysCompactCount < 1)
+    || ((PSMarkSweep::total_invocations() % MarkSweepAlwaysCompactCount) != 0);
 
   size_t allowed_deadspace = 0;
   if (skip_dead) {
diff -r 0cfe4d79060c -r 7663e46f3a54 hotspot/src/share/vm/memory/space.hpp
--- a/hotspot/src/share/vm/memory/space.hpp	Fri Nov 18 12:52:27 2011 -0500
+++ b/hotspot/src/share/vm/memory/space.hpp	Mon Nov 21 07:47:34 2011 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 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
@@ -533,7 +533,8 @@
    * by the MarkSweepAlwaysCompactCount parameter.                           \
    */                                                                        \
   int invocations = SharedHeap::heap()->perm_gen()->stat_record()->invocations;\
-  bool skip_dead = ((invocations % MarkSweepAlwaysCompactCount) != 0);       \
+  bool skip_dead = (MarkSweepAlwaysCompactCount < 1)                         \
+    ||((invocations % MarkSweepAlwaysCompactCount) != 0);                    \
                                                                              \
   size_t allowed_deadspace = 0;                                              \
   if (skip_dead) {                                                           \