--- src/lib/libast/vmalloc/vmhdr.h
+++ src/lib/libast/vmalloc/vmhdr.h	2012-01-19 09:45:13.651645599 +0000
@@ -149,6 +149,9 @@ extern void		_vmmessage _ARG_((const cha
 #endif /*DEBUG*/
 
 #define VMPAGESIZE	8192
+#if defined(__linux__) && !defined(_lib_getpagesize)
+#define _lib_getpagesize	1
+#endif
 #if _lib_getpagesize
 #define GETPAGESIZE(x)	((x) ? (x) : ((x)=getpagesize()) )
 #else
--- src/lib/libast/vmalloc/vmmopen.c
+++ src/lib/libast/vmalloc/vmmopen.c	2012-01-20 11:13:11.743644776 +0000
@@ -58,8 +58,10 @@ void _STUB_vmmapopen(){}
 /* magic word signaling file/segment is ready */
 #define	MM_MAGIC	((unsigned int)(('P'<<24) | ('&'<<16) | ('N'<<8) | ('8')) )
 
+#ifndef __linux__
 /* default mimimum region size */
 #define MM_MINSIZE	(64*_Vmpagesize)
+#endif
 
 /* macros to get the data section and size */
 #define MMHEAD(file)	ROUND(sizeof(Mmvm_t)+strlen(file), ALIGN)
@@ -135,7 +137,12 @@ static Mmvm_t* mmfix(Mmvm_t* mmvm, Mmdis
 		if(mmdc->proj < 0)
 		{	munmap((Void_t*)mmvm, size); 
 			mmvm = (Mmvm_t*)mmap(base, size, (PROT_READ|PROT_WRITE),
-					     (MAP_FIXED|MAP_SHARED), fd, (off_t)0 );
+#if (defined(__ia64__) || defined(__s390x__)) && defined(MAP_32BIT)
+					     (MAP_32BIT|MAP_SHARED),
+#else
+					     (MAP_FIXED|MAP_SHARED),
+#endif
+					     fd, (off_t)0 );
 		}
 		else
 		{	shmdt((Void_t*)mmvm);
@@ -162,10 +169,18 @@ static int mminit(Mmdisc_t* mmdc)
 
 	if(mmdc->mmvm) /* already done this */
 		return 0;
-
+#ifdef MM_MINSIZE
 	/* fixed size region so make it reasonably large */
 	if((size = mmdc->size) < MM_MINSIZE )
 		size =  MM_MINSIZE;
+#else
+	if (sizeof(void*) > 32)
+		extent = ROUND(0x80000,_Vmpagesize);
+	else
+		extent = ROUND(0x40000,_Vmpagesize);
+	if((size = mmdc->size) < extent)
+		size = extent;
+#endif
 	size += MMHEAD(mmdc->file) + ALIGN;
 	size  = ROUND(size, _Vmpagesize);