Index: src/backend/storage/lmgr/lwlock.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/storage/lmgr/lwlock.c,v
retrieving revision 1.55
diff -u -4 -r1.55 lwlock.c
--- src/backend/storage/lmgr/lwlock.c	2 Jan 2010 16:57:52 -0000	1.55
+++ src/backend/storage/lmgr/lwlock.c	11 Jan 2010 16:40:03 -0000
@@ -57,9 +57,11 @@
  *
  * LWLock is between 16 and 32 bytes on all known platforms, so these two
  * cases are sufficient.
  */
-#define LWLOCK_PADDED_SIZE	(sizeof(LWLock) <= 16 ? 16 : 32)
+/* #define LWLOCK_PADDED_SIZE	(sizeof(LWLock) <= 16 ? 16 : 32) */
+
+#define LWLOCK_PADDED_SIZE 64
 
 typedef union LWLockPadded
 {
 	LWLock		lock;