diff src/cpu/x86/vm/macroAssembler_x86.cpp @ 12835:69944b868a32

8014555: G1: Memory ordering problem with Conc refinement and card marking Summary: Add a StoreLoad barrier in the G1 post-barrier to fix a race with concurrent refinement. Also-reviewed-by: martin.doerr@sap.com Reviewed-by: iveresov, tschatzl, brutisso, roland, kvn
author mgerdin
date Tue, 08 Oct 2013 17:35:51 +0200
parents 7944aba7ba41
children 209aa13ab8c0
line wrap: on
line diff
--- a/src/cpu/x86/vm/macroAssembler_x86.cpp	Fri Oct 04 13:33:02 2013 +0200
+++ b/src/cpu/x86/vm/macroAssembler_x86.cpp	Tue Oct 08 17:35:51 2013 +0200
@@ -3389,13 +3389,18 @@
   const Register card_addr = tmp;
   lea(card_addr, as_Address(ArrayAddress(cardtable, index)));
 #endif
-  cmpb(Address(card_addr, 0), 0);
+  cmpb(Address(card_addr, 0), (int)G1SATBCardTableModRefBS::g1_young_card_val());
   jcc(Assembler::equal, done);
 
+  membar(Assembler::Membar_mask_bits(Assembler::StoreLoad));
+  cmpb(Address(card_addr, 0), (int)CardTableModRefBS::dirty_card_val());
+  jcc(Assembler::equal, done);
+
+
   // storing a region crossing, non-NULL oop, card is clean.
   // dirty card and log.
 
-  movb(Address(card_addr, 0), 0);
+  movb(Address(card_addr, 0), (int)CardTableModRefBS::dirty_card_val());
 
   cmpl(queue_index, 0);
   jcc(Assembler::equal, runtime);