1.1 --- a/src/share/vm/gc_implementation/parallelScavenge/cardTableExtension.cpp Thu Jun 10 08:27:35 2010 -0700
1.2 +++ b/src/share/vm/gc_implementation/parallelScavenge/cardTableExtension.cpp Wed Jun 23 08:35:31 2010 -0700
1.3 @@ -1,5 +1,5 @@
1.4 /*
1.5 - * Copyright (c) 2001, 2008, Oracle and/or its affiliates. All rights reserved.
1.6 + * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
1.7 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.8 *
1.9 * This code is free software; you can redistribute it and/or modify it
1.10 @@ -566,14 +566,14 @@
1.11 #endif
1.12
1.13 // Commit new or uncommit old pages, if necessary.
1.14 - resize_commit_uncommit(changed_region, new_region);
1.15 + if (resize_commit_uncommit(changed_region, new_region)) {
1.16 + // Set the new start of the committed region
1.17 + resize_update_committed_table(changed_region, new_region);
1.18 + }
1.19
1.20 // Update card table entries
1.21 resize_update_card_table_entries(changed_region, new_region);
1.22
1.23 - // Set the new start of the committed region
1.24 - resize_update_committed_table(changed_region, new_region);
1.25 -
1.26 // Update the covered region
1.27 resize_update_covered_table(changed_region, new_region);
1.28
1.29 @@ -604,8 +604,9 @@
1.30 debug_only(verify_guard();)
1.31 }
1.32
1.33 -void CardTableExtension::resize_commit_uncommit(int changed_region,
1.34 +bool CardTableExtension::resize_commit_uncommit(int changed_region,
1.35 MemRegion new_region) {
1.36 + bool result = false;
1.37 // Commit new or uncommit old pages, if necessary.
1.38 MemRegion cur_committed = _committed[changed_region];
1.39 assert(_covered[changed_region].end() == new_region.end(),
1.40 @@ -675,20 +676,31 @@
1.41 "card table expansion");
1.42 }
1.43 }
1.44 + result = true;
1.45 } else if (new_start_aligned > cur_committed.start()) {
1.46 // Shrink the committed region
1.47 +#if 0 // uncommitting space is currently unsafe because of the interactions
1.48 + // of growing and shrinking regions. One region A can uncommit space
1.49 + // that it owns but which is being used by another region B (maybe).
1.50 + // Region B has not committed the space because it was already
1.51 + // committed by region A.
1.52 MemRegion uncommit_region = committed_unique_to_self(changed_region,
1.53 MemRegion(cur_committed.start(), new_start_aligned));
1.54 if (!uncommit_region.is_empty()) {
1.55 if (!os::uncommit_memory((char*)uncommit_region.start(),
1.56 uncommit_region.byte_size())) {
1.57 - vm_exit_out_of_memory(uncommit_region.byte_size(),
1.58 - "card table contraction");
1.59 + // If the uncommit fails, ignore it. Let the
1.60 + // committed table resizing go even though the committed
1.61 + // table will over state the committed space.
1.62 }
1.63 }
1.64 +#else
1.65 + assert(!result, "Should be false with current workaround");
1.66 +#endif
1.67 }
1.68 assert(_committed[changed_region].end() == cur_committed.end(),
1.69 "end should not change");
1.70 + return result;
1.71 }
1.72
1.73 void CardTableExtension::resize_update_committed_table(int changed_region,
