There were two changes, one in g1CollectedHeap.cpp and another in cfgnode.cpp,
intended for debugging/working around issues which got inadvertently pushed into
hotspot-gc and hotspot repos:-

--- a/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp Tue Jul 07 14:23:00 2009 -0400
+++ b/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp Tue Jul 14 15:40:39 2009 -0700
@@ -1655,11 +1655,14 @@ void G1CollectedHeap::iterate_dirty_card
// Computes the sum of the storage used by the various regions.
size_t G1CollectedHeap::used() const {
- assert(Heap_lock->owner() != NULL,
- "Should be owned on this thread's behalf.");
+ // Temporarily, until 6859911 is fixed. XXX
+ // assert(Heap_lock->owner() != NULL,
+ // "Should be owned on this thread's behalf.");
size_t result = _summary_bytes_used;
- if (_cur_alloc_region != NULL)
- result += _cur_alloc_region->used();
+ // Read only once in case it is set to NULL concurrently
+ HeapRegion* hr = _cur_alloc_region;
+ if (hr != NULL)
+ result += hr->used();
return result;
}

--- a/src/share/vm/opto/cfgnode.cpp Thu Mar 12 18:16:36 2009 -0700
+++ b/src/share/vm/opto/cfgnode.cpp Tue Jul 14 15:40:39 2009 -0700
@@ -1789,7 +1789,7 @@ Node *PhiNode::Ideal(PhaseGVN *phase, bo
#ifdef _LP64
// Push DecodeN down through phi.
// The rest of phi graph will transform by split EncodeP node though phis up.
- if (UseCompressedOops && can_reshape && progress == NULL) {
+ if (UseNewCode && UseCompressedOops && can_reshape && progress == NULL) {
bool may_push = true;
bool has_decodeN = false;
Node* in_decodeN = NULL;


We need to back out these unintended deltas.