7040068: CMS: Possibly unsafe initialization of BlockOffsetArrayUseUnallocatedBlock
BlockOffsetArrayUseUnallocatedBlock was intended to be turned off as part of BUG 6948538 but a code line in collectorPolicy.cpp actually kept it turned on.
Reviewed-by: jwilhelm, ysr
diff --git a/hotspot/src/share/vm/memory/collectorPolicy.cpp b/hotspot/src/share/vm/memory/collectorPolicy.cpp
index 61efdd8..7ad2beb 100644
--- a/hotspot/src/share/vm/memory/collectorPolicy.cpp
+++ b/hotspot/src/share/vm/memory/collectorPolicy.cpp
@@ -265,8 +265,6 @@
MaxHeapSize = align_size_up(MaxHeapSize, max_alignment());
always_do_update_barrier = UseConcMarkSweepGC;
- BlockOffsetArrayUseUnallocatedBlock =
- BlockOffsetArrayUseUnallocatedBlock || ParallelGCThreads > 0;
// Check validity of heap flags
assert(OldSize % min_alignment() == 0, "old space alignment");
diff --git a/hotspot/src/share/vm/runtime/globals.hpp b/hotspot/src/share/vm/runtime/globals.hpp
index c16f886..59f8fb9 100644
--- a/hotspot/src/share/vm/runtime/globals.hpp
+++ b/hotspot/src/share/vm/runtime/globals.hpp
@@ -1824,7 +1824,7 @@
develop(bool, VerifyBlockOffsetArray, false, \
"Do (expensive!) block offset array verification") \
\
- product(bool, BlockOffsetArrayUseUnallocatedBlock, false, \
+ diagnostic(bool, BlockOffsetArrayUseUnallocatedBlock, false, \
"Maintain _unallocated_block in BlockOffsetArray" \
" (currently applicable only to CMS collector)") \
\
