diff --git a/qse/cmd/awk/awk.c b/qse/cmd/awk/awk.c
index 22a0759e..1bb116f7 100644
--- a/qse/cmd/awk/awk.c
+++ b/qse/cmd/awk/awk.c
@@ -1,5 +1,5 @@
 /*
- * $Id: awk.c 336 2010-07-24 12:43:26Z hyunghwan.chung $
+ * $Id: awk.c 337 2010-07-28 13:27:03Z hyunghwan.chung $
  *
     Copyright 2006-2009 Chung, Hyung-Hwan.
     This file is part of QSE.
@@ -69,6 +69,7 @@ struct arg_t
 
 	int          opton;
 	int          optoff;
+	qse_ulong_t  memlimit;
 };
 
 struct gvmv_t
@@ -358,6 +359,7 @@ static void print_usage (QSE_FILE* out, const qse_char_t* argv0)
 	qse_fprintf (out, QSE_T(" -o/--deparsed-file   deparsedfile set the deparsing output file\n"));
 	qse_fprintf (out, QSE_T(" -F/--field-separator string       set a field separator(FS)\n"));
 	qse_fprintf (out, QSE_T(" -v/--assign          var=value    add a global variable with a value\n"));
+	qse_fprintf (out, QSE_T(" -m/--memory-limit    number       limit the memory usage (bytes)\n"));
 
 	for (j = 0; opttab[j].name != QSE_NULL; j++)
 	{
@@ -392,13 +394,14 @@ static int comparg (int argc, qse_char_t* argv[], struct arg_t* arg)
 		{ QSE_T(":field-separator"), QSE_T('F') },
 		{ QSE_T(":deparsed-file"),   QSE_T('o') },
 		{ QSE_T(":assign"),          QSE_T('v') },
+		{ QSE_T(":memory-limit"),    QSE_T('m') },
 
 		{ QSE_T("help"),             QSE_T('h') }
 	};
 
 	static qse_opt_t opt = 
 	{
-		QSE_T("dc:f:F:o:v:h"),
+		QSE_T("dc:f:F:o:v:m:h"),
 		lng
 	};
 
@@ -520,6 +523,12 @@ static int comparg (int argc, qse_char_t* argv[], struct arg_t* arg)
 				break;
 			}
 
+			case QSE_T('m'):
+			{
+				arg->memlimit = qse_strtoulong (opt.arg);
+				break;
+			}
+
 			case QSE_T('\0'):
 			{
 				/* a long option with no corresponding short option */
@@ -688,7 +697,15 @@ qse_htb_walk_t add_global (qse_htb_t* map, qse_htb_pair_t* pair, void* arg)
 	return QSE_HTB_WALK_FORWARD;
 }
 
-static int real_awk_main (int argc, qse_char_t* argv[], qse_mmgr_t* mmgr)
+static qse_mmgr_t xma_mmgr = 
+{
+	qse_xma_alloc,
+	QSE_NULL,
+	qse_xma_free,
+	QSE_NULL
+};
+
+static int awk_main (int argc, qse_char_t* argv[])
 {
 	qse_awk_t* awk = QSE_NULL;
 	qse_awk_rtx_t* rtx = QSE_NULL;
@@ -696,7 +713,6 @@ static int real_awk_main (int argc, qse_char_t* argv[], qse_mmgr_t* mmgr)
 #if 0
 	qse_awk_rcb_t rcb;
 #endif
-
 	int i;
 	struct arg_t arg;
 	int ret = -1;
@@ -704,6 +720,7 @@ static int real_awk_main (int argc, qse_char_t* argv[], qse_mmgr_t* mmgr)
 	/* TODO: change it to support multiple source files */
 	qse_awk_parsestd_in_t psin;
 	qse_awk_parsestd_out_t psout;
+	qse_mmgr_t* mmgr = QSE_NULL;
 
 	memset (&arg, 0, QSE_SIZEOF(arg));
 
@@ -724,8 +741,19 @@ static int real_awk_main (int argc, qse_char_t* argv[], qse_mmgr_t* mmgr)
 		psout.u.file = arg.osf;
 	}
 
+	if (arg.memlimit > 0)
+	{
+		xma_mmgr.udd = qse_xma_open (QSE_NULL, 0, arg.memlimit);
+		if (xma_mmgr.udd == QSE_NULL)
+		{
+			qse_printf (QSE_T("ERROR: cannot open memory heap\n"));
+			goto oops;
+		}
+		mmgr = &xma_mmgr;
+	}
+
 	awk = qse_awk_openstdwithmmgr (mmgr, 0);
-	//awk = qse_awk_openstd (0);
+	/*awk = qse_awk_openstd (0);*/
 	if (awk == QSE_NULL)
 	{
 		qse_printf (QSE_T("ERROR: cannot open awk\n"));
@@ -814,38 +842,14 @@ static int real_awk_main (int argc, qse_char_t* argv[], qse_mmgr_t* mmgr)
 	}
 
 oops:
-	if (rtx != QSE_NULL) qse_awk_rtx_close (rtx);
-	if (awk != QSE_NULL) qse_awk_close (awk);
+	if (rtx) qse_awk_rtx_close (rtx);
+	if (awk) qse_awk_close (awk);
 
+	if (xma_mmgr.udd) qse_xma_close (xma_mmgr.udd);
 	freearg (&arg);
 	return ret;
 }
 
-static int awk_main (int argc, qse_char_t* argv[])
-{
-	int n;
-
-	qse_mmgr_t mmgr = 
-	{
-		qse_xma_alloc,
-		QSE_NULL,
-		qse_xma_free,
-		QSE_NULL
-	};
-
-	mmgr.udd = qse_xma_open (QSE_NULL, 0, 1000000);
-	if (mmgr.udd == QSE_NULL)
-	{
-		qse_printf (QSE_T("ERROR: cannot open memory heap\n"));
-		return -1;
-	}
-
-	n = real_awk_main (argc, argv, &mmgr);
-
-	qse_xma_close (mmgr.udd);
-	return n;
-}
-
 int qse_main (int argc, qse_achar_t* argv[])
 {
 	return qse_runmain (argc, argv, awk_main);
diff --git a/qse/cmd/sed/sed.c b/qse/cmd/sed/sed.c
index cf728fb8..30fb24f6 100644
--- a/qse/cmd/sed/sed.c
+++ b/qse/cmd/sed/sed.c
@@ -24,6 +24,7 @@
 #include <qse/cmn/chr.h>
 #include <qse/cmn/opt.h>
 #include <qse/cmn/sio.h>
+#include <qse/cmn/xma.h>
 #include <qse/cmn/misc.h>
 #include <qse/cmn/stdio.h>
 #include <qse/cmn/main.h>
@@ -32,6 +33,15 @@ static const qse_char_t* g_script_file = QSE_NULL;
 static qse_char_t* g_script = QSE_NULL;
 static const qse_char_t* g_infile = QSE_NULL;
 static int g_option = 0;
+static qse_ulong_t g_memlimit = 0;
+
+static qse_mmgr_t xma_mmgr = 
+{
+	qse_xma_alloc,
+	QSE_NULL,
+	qse_xma_free,
+	QSE_NULL
+};
 
 static qse_ssize_t in (
 	qse_sed_t* sed, qse_sed_io_cmd_t cmd,
@@ -130,14 +140,15 @@ static void print_usage (QSE_FILE* out, int argc, qse_char_t* argv[])
 	qse_fprintf (out, QSE_T(" -r        allow {n,m} in a regular expression\n"));
 	qse_fprintf (out, QSE_T(" -s        allow text on the same line as c, a, i\n"));
 	qse_fprintf (out, QSE_T(" -l        ensure a newline at text end\n"));
-	qse_fprintf (out, QSE_T(" -f file   specifie a s script file\n"));
+	qse_fprintf (out, QSE_T(" -f file   specify a script file\n"));
+	qse_fprintf (out, QSE_T(" -m number specify the maximum amount of memory to use in bytes\n"));
 }
 
 static int handle_args (int argc, qse_char_t* argv[])
 {
 	static qse_opt_t opt = 
 	{
-		QSE_T("hnarslf:"),
+		QSE_T("hnarslf:m:"),
 		QSE_NULL
 	};
 	qse_cint_t c;
@@ -193,6 +204,10 @@ static int handle_args (int argc, qse_char_t* argv[])
 			case QSE_T('f'):
 				g_script_file = opt.arg;
 				break;
+
+			case QSE_T('m'):
+				g_memlimit = qse_strtoulong (opt.arg);
+				break;
 		}
 	}
 
@@ -248,6 +263,7 @@ qse_char_t* load_script_file (const qse_char_t* file)
 
 int sed_main (int argc, qse_char_t* argv[])
 {
+	qse_mmgr_t* mmgr = QSE_NULL;
 	qse_sed_t* sed = QSE_NULL;
 	int ret = -1;
 
@@ -257,7 +273,18 @@ int sed_main (int argc, qse_char_t* argv[])
 
 	ret = -1;
 
-	sed = qse_sed_open (QSE_NULL, 0);
+	if (g_memlimit > 0)
+	{
+		xma_mmgr.udd = qse_xma_open (QSE_NULL, 0, g_memlimit);
+		if (xma_mmgr.udd == QSE_NULL)
+		{
+			qse_printf (QSE_T("ERROR: cannot open memory heap\n"));
+			goto oops;
+		}
+		mmgr = &xma_mmgr;
+	}
+
+	sed = qse_sed_open (mmgr, 0);
 	if (sed == QSE_NULL)
 	{
 		qse_fprintf (QSE_STDERR, QSE_T("cannot open a stream editor\n"));
@@ -325,7 +352,8 @@ int sed_main (int argc, qse_char_t* argv[])
 	ret = 0;
 
 oops:
-	if (sed != QSE_NULL) qse_sed_close (sed);
+	if (sed) qse_sed_close (sed);
+	if (xma_mmgr.udd) qse_xma_close (xma_mmgr.udd);
 	if (g_script_file != QSE_NULL && g_script != QSE_NULL) 
 		QSE_MMGR_FREE (QSE_MMGR_GETDFL(), g_script);
 	return ret;
diff --git a/qse/include/qse/cmn/xma.h b/qse/include/qse/cmn/xma.h
index 0d9b60e3..add9cf4b 100644
--- a/qse/include/qse/cmn/xma.h
+++ b/qse/include/qse/cmn/xma.h
@@ -27,13 +27,18 @@
 typedef struct qse_xma_t qse_xma_t;
 typedef struct qse_xma_blk_t qse_xma_blk_t;
 
+#define QSE_XMA_FIXED 32
+#define QSE_XMA_SIZE_BITS ((QSE_SIZEOF_SIZE_T*8)-1)
+
 struct qse_xma_t
 {
 	QSE_DEFINE_COMMON_FIELDS (xma)
 
 	qse_xma_blk_t* head;
-	qse_xma_blk_t* xfree[100];
+	qse_xma_blk_t* xfree[QSE_XMA_FIXED + QSE_XMA_SIZE_BITS + 1];
+	qse_size_t     bdec;
 
+#ifdef QSE_XMA_ENABLE_STAT
 	struct
 	{
 		qse_size_t total;
@@ -42,6 +47,7 @@ struct qse_xma_t
 		qse_size_t nused;
 		qse_size_t nfree;
 	} stat;
+#endif
 };
 
 #ifdef __cplusplus
@@ -75,6 +81,12 @@ void* qse_xma_alloc (
 	qse_size_t size
 );
 
+void* qse_xma_realloc (
+	qse_xma_t* xma, 
+	void*      b,
+	qse_size_t size
+);
+
 void qse_xma_free (
 	qse_xma_t* xma,
 	void*      b
diff --git a/qse/include/qse/types.h b/qse/include/qse/types.h
index e9331a6c..77b72fc0 100644
--- a/qse/include/qse/types.h
+++ b/qse/include/qse/types.h
@@ -1,5 +1,5 @@
 /*
- * $Id: types.h 287 2009-09-15 10:01:02Z hyunghwan.chung $
+ * $Id: types.h 337 2010-07-28 13:27:03Z hyunghwan.chung $
  *
     Copyright 2006-2009 Chung, Hyung-Hwan.
     This file is part of QSE.
@@ -239,10 +239,12 @@ typedef qse_uint8_t qse_byte_t;
  * The qse_size_t type defines an unsigned integer type that is as large as
  * to hold a pointer value.
  */
-#ifdef __SIZE_TYPE__
+#if defined(__SIZE_TYPE__) && defined(__SIZEOF_SIZE_T__)
 	typedef __SIZE_TYPE__ qse_size_t;
+#	define QSE_SIZEOF_SIZE_T __SIZEOF_SIZE_T__
 #else
 	typedef qse_uint_t  qse_size_t;
+#	define QSE_SIZEOF_SIZE_T QSE_SIZEOF_INT_T
 #endif
 
 /**
diff --git a/qse/lib/cmn/syscall.h b/qse/lib/cmn/syscall.h
index 217cc2a1..b422959e 100644
--- a/qse/lib/cmn/syscall.h
+++ b/qse/lib/cmn/syscall.h
@@ -1,5 +1,5 @@
 /*
- * $Id: syscall.h 287 2009-09-15 10:01:02Z hyunghwan.chung $
+ * $Id: syscall.h 337 2010-07-28 13:27:03Z hyunghwan.chung $
  *
     Copyright 2006-2009 Chung, Hyung-Hwan.
     This file is part of QSE.
@@ -50,6 +50,9 @@
 #ifdef HAVE_SYS_RESOURCE_H
 #	include <sys/resource.h>
 #endif
+#ifdef HAVE_SYS_STAT_H
+#	include <sys/stat.h>
+#endif
 
 #if defined(QSE_USE_SYSCALL) && defined(HAVE_SYS_SYSCALL_H)
 #	include <sys/syscall.h>
diff --git a/qse/lib/cmn/xma.c b/qse/lib/cmn/xma.c
index b1ba68f2..653e9ffe 100644
--- a/qse/lib/cmn/xma.c
+++ b/qse/lib/cmn/xma.c
@@ -27,12 +27,21 @@
 #define SYS_TO_USR(_) (((qse_xma_blk_t*)_) + 1)
 #define USR_TO_SYS(_) (((qse_xma_blk_t*)_) - 1)
 
+/*
+ * the xfree array is divided into three region
+ * 0 ....................... FIXED ......................... XFIMAX-1 ... XFIMAX
+ * |  small fixed-size chains |     large  chains                | huge chain |
+ */
+#define FIXED QSE_XMA_FIXED
 #define XFIMAX(xma) (QSE_COUNTOF(xma->xfree)-1)
+#define _XFI(size) (((size) / ALIGN) - 1)
+#define _XFI_LARGE(xma,size) (szlog2(size) - (xma)->bdec + FIXED)
+#define XFI(xma,size) ((_XFI(size) < FIXED)? _XFI(size): _XFI_LARGE(xma,size))
 
 struct qse_xma_blk_t 
 {
 	qse_size_t avail: 1;
-	qse_size_t size: (sizeof(qse_size_t)*8)-1; /**< block size */
+	qse_size_t size: QSE_XMA_SIZE_BITS;/**< block size */
 
 	struct
 	{
@@ -49,6 +58,46 @@ struct qse_xma_blk_t
 
 QSE_IMPLEMENT_COMMON_FUNCTIONS (xma)
 
+static QSE_INLINE qse_size_t szlog2 (qse_size_t n)
+{
+	/*
+	 * 2**x = n;
+	 * x = log2(n);
+	 * -------------------------------------------
+	 * 	unsigned int x = 0;
+	 * 	while((n >> x) > 1) ++x;
+	 * 	return x;
+	 */
+
+#define BITS (QSE_SIZEOF_SIZE_T * 8)
+	int x = BITS - 1;
+
+#if QSE_SIZEOF_SIZE_T >= 32
+#	error qse_size_t too large. unsupported platform
+#endif
+
+#if QSE_SIZEOF_SIZE_T >= 16
+	if ((n & (~(qse_size_t)0 << (BITS-64))) == 0) { x -= 64; n <<= 64; }
+#endif
+#if QSE_SIZEOF_SIZE_T >= 8
+	if ((n & (~(qse_size_t)0 << (BITS-32))) == 0) { x -= 32; n <<= 32; }
+#endif
+#if QSE_SIZEOF_SIZE_T >= 4 
+	if ((n & (~(qse_size_t)0 << (BITS-16))) == 0) { x -= 16; n <<= 16; }
+#endif
+#if QSE_SIZEOF_SIZE_T >= 2
+	if ((n & (~(qse_size_t)0 << (BITS-8))) == 0) { x -= 8; n <<= 8; }
+#endif
+#if QSE_SIZEOF_SIZE_T >= 1
+	if ((n & (~(qse_size_t)0 << (BITS-4))) == 0) { x -= 4; n <<= 4; }
+#endif
+	if ((n & (~(qse_size_t)0 << (BITS-2))) == 0) { x -= 2; n <<= 2; }
+	if ((n & (~(qse_size_t)0 << (BITS-1))) == 0) { x -= 1; }
+
+	return x;
+#undef BITS
+}
+
 qse_xma_t* qse_xma_open (qse_mmgr_t* mmgr, qse_size_t ext, qse_size_t size)
 {
 	qse_xma_t* xma;
@@ -84,35 +133,42 @@ void qse_xma_close (qse_xma_t* xma)
 qse_xma_t* qse_xma_init (qse_xma_t* xma, qse_mmgr_t* mmgr, qse_size_t size)
 {
 	qse_xma_blk_t* free;
+	qse_size_t xfi;
 
+	/* adjust 'size' to be large enough to hold a single smallest block */
 	if (size < HDRSIZE + ALIGN) size = HDRSIZE + ALIGN;
 
+	/* allocate a memory chunk to use for actual memory allocation */
 	free = QSE_MMGR_ALLOC (mmgr, size);
 	if (free == QSE_NULL) return QSE_NULL;
 	
-	/* make the entire region available. the allocatable block begins
-	 * past the xma structure */
+	/* initialize the header part of the free chunk */
+	free->avail = 1;
 	free->size = size - HDRSIZE; /* size excluding the block header */
 	free->f.prev = QSE_NULL;
 	free->f.next = QSE_NULL;
 	free->b.next = QSE_NULL;
 	free->b.prev = QSE_NULL;
-	free->avail = 1;
 
 	QSE_MEMSET (xma, 0, QSE_SIZEOF(*xma));
 	xma->mmgr = mmgr;
+	xma->bdec = szlog2(FIXED*ALIGN); /* precalculate the decrement value */
 
-	/* the entire region is a free block */
-	xma->xfree[XFIMAX(xma)] = free;
-	xma->head = free;
+	/* the entire chunk is a free block */
+	xfi = XFI(xma,free->size);
+	if (xfi > XFIMAX(xma)) xfi = XFIMAX(xma);
+	xma->xfree[xfi] = free; /* locate it at the right slot */
+	xma->head = free; /* store it for furture reference */
 
 	/* initialize some statistical variables */
+#ifdef QSE_XMA_ENABLE_STAT
 	xma->stat.total = size;
 	xma->stat.alloc = 0;
 	xma->stat.avail = size - HDRSIZE;
 	xma->stat.nfree = 1;
 	xma->stat.nused = 0;
-
+#endif
+	
 	return xma;
 }
 
@@ -121,9 +177,9 @@ void qse_xma_fini (qse_xma_t* xma)
 	QSE_MMGR_FREE (xma->mmgr, xma->head);
 }
 
-static QSE_INLINE void attach_block_to_freelist (qse_xma_t* xma, qse_xma_blk_t* b)
+static QSE_INLINE void attach_to_freelist (qse_xma_t* xma, qse_xma_blk_t* b)
 {
-	qse_size_t xfi = (b->size / ALIGN) - 1;
+	qse_size_t xfi = XFI(xma,b->size);
 	if (xfi > XFIMAX(xma)) xfi = XFIMAX(xma);
 
 	b->f.prev = QSE_NULL;
@@ -132,21 +188,26 @@ static QSE_INLINE void attach_block_to_freelist (qse_xma_t* xma, qse_xma_blk_t*
 	xma->xfree[xfi] = b;		
 }
 
-static QSE_INLINE void detach_block_from_freelist (qse_xma_t* xma, qse_xma_blk_t* b)
+static QSE_INLINE void detach_from_freelist (qse_xma_t* xma, qse_xma_blk_t* b)
 {
-	qse_xma_blk_t* x, * y;
+	qse_xma_blk_t* p, * n;
 
-	x = b->f.prev;
-	y = b->f.next;
+	p = b->f.prev;
+	n = b->f.next;
 
-	if (x) x->f.next = y;
+	if (p)
+	{
+		p->f.next = n;
+	}
 	else 
 	{
-		qse_size_t xfi = (b->size / ALIGN) - 1;
+		qse_size_t xfi = XFI(xma,b->size);
 		if (xfi > XFIMAX(xma)) xfi = XFIMAX(xma);
-		xma->xfree[xfi] = y;
+
+		QSE_ASSERT (b == xma->xfree[xfi]);
+		xma->xfree[xfi] = n;
 	}
-	if (y) y->f.prev = x;
+	if (n) n->f.prev = p;
 }
 
 static qse_xma_blk_t* alloc_from_freelist (
@@ -158,45 +219,48 @@ static qse_xma_blk_t* alloc_from_freelist (
 	{
 		if (free->size >= size)
 		{
-			qse_size_t rem;
+			detach_from_freelist (xma, free);
 
-			rem  = free->size - size;
+			qse_size_t rem = free->size - size;
 			if (rem > HDRSIZE)
 			{
 				qse_xma_blk_t* tmp;
 
 				/* the remaining part is large enough to hold 
-				 * another block. let's split it */
+				 * another block. let's split it 
+				 */
+
+				/* shrink the size of the 'free' block */
+				free->size = size;
+
+				/* let 'tmp' point to the remaining part */
 				tmp = (qse_xma_blk_t*)(((qse_byte_t*)(free + 1)) + size);
 
+				/* initialize some fields */
 				tmp->avail = 1;
 				tmp->size = rem - HDRSIZE;
+
+				/* link 'tmp' to the block list */
 				tmp->b.next = free->b.next;
 				tmp->b.prev = free;
 				if (free->b.next) free->b.next->b.prev = tmp;
 				free->b.next = tmp;
-				free->size = size;
 
-				tmp->f.next = free->f.next;
-				free->f.next = tmp;
+				/* add the remaining part to the free list */
+				attach_to_freelist (xma, tmp);
 
+#ifdef QSE_XMA_ENABLE_STAT
 				xma->stat.avail -= HDRSIZE;
+#endif
 			}
+#ifdef QSE_XMA_ENABLE_STAT
 			else
 			{
 				/* decrement the number of free blocks as the current
 				 * block is allocated as a whole without being split */
 				xma->stat.nfree--;
 			}
-
-
-			if (free->f.next) free->f.next->f.prev = free->f.prev;
-			if (free->f.prev) free->f.prev->f.next = free->f.next;
-			else
-			{
-				QSE_ASSERT (xma->xfree[xfi] == free);
-				xma->xfree[xfi] = free->f.next;
-			}
+#endif
 
 			free->avail = 0;
 			/*
@@ -204,9 +268,11 @@ static qse_xma_blk_t* alloc_from_freelist (
 			free->f.prev = QSE_NULL;
 			*/
 
+#ifdef QSE_XMA_ENABLE_STAT
 			xma->stat.nused++;
 			xma->stat.alloc += free->size;
 			xma->stat.avail -= free->size;
+#endif
 			return free;
 		}
 	}
@@ -226,38 +292,61 @@ void* qse_xma_alloc (qse_xma_t* xma, qse_size_t size)
 	size = ((size + ALIGN - 1) / ALIGN) * ALIGN;
 
 	QSE_ASSERT (size >= ALIGN);
-	xfi = (size / ALIGN) - 1;
+	xfi = XFI(xma,size);
 	if (xfi > XFIMAX(xma)) xfi = XFIMAX(xma);
 
-	if (xfi < XFIMAX(xma) && xma->xfree[xfi])
+	/*if (xfi < XFIMAX(xma) && xma->xfree[xfi])*/
+	if (xfi < FIXED && xma->xfree[xfi])
 	{
 		/* try the best fit */
-//printf ("FOUND A BEST FIT...............\n");
 		free = xma->xfree[xfi];
 
 		QSE_ASSERT (free->avail != 0);
 		QSE_ASSERT (free->size == size);
 
-		detach_block_from_freelist (xma, free);
+		detach_from_freelist (xma, free);
 		free->avail = 0;
 
+#ifdef QSE_XMA_ENABLE_STAT
 		xma->stat.nfree--;
 		xma->stat.nused++;
 		xma->stat.alloc += free->size;
 		xma->stat.avail -= free->size;
+#endif
+	}
+	else if (xfi == XFIMAX(xma))
+	{
+		/* huge block */
+		free = alloc_from_freelist (xma, XFIMAX(xma), size);
+		if (free == QSE_NULL) return QSE_NULL;
 	}
 	else
 	{
-		/* traverses the chain of free blocks */
-		free = alloc_from_freelist (xma, XFIMAX(xma), size);
+		if (xfi >= FIXED)
+		{
+			/* get the block from its own large chain */
+			free = alloc_from_freelist (xma, xfi, size);
+			if (free == QSE_NULL)
+			{
+				/* borrow a large block from the huge block chain */
+				free = alloc_from_freelist (xma, XFIMAX(xma), size);
+			}
+		}
+		else
+		{
+			/* borrow a small block from the huge block chain */
+			free = alloc_from_freelist (xma, XFIMAX(xma), size);
+			if (free == QSE_NULL) xfi = FIXED - 1;
+		}
+
 		if (free == QSE_NULL)
 		{
+			/* try each large block chain left */
 			for (++xfi; xfi < XFIMAX(xma) - 1; xfi++)
 			{
 				free = alloc_from_freelist (xma, xfi, size);
 				if (free != QSE_NULL) break;
 			}
-
 			if (free == QSE_NULL) return QSE_NULL;
 		}
 	}
@@ -265,15 +354,23 @@ void* qse_xma_alloc (qse_xma_t* xma, qse_size_t size)
 	return SYS_TO_USR(free);
 }
 
+void* qse_xma_realloc (qse_xma_t* xma, void* b, qse_size_t size)
+{
+	/* TODO */
+	return QSE_NULL;
+}
+
 void qse_xma_free (qse_xma_t* xma, void* b)
 {
 	qse_xma_blk_t* blk = USR_TO_SYS(b);
 
 	/*QSE_ASSERT (blk->f.next == QSE_NULL);*/
 
+#ifdef QSE_XMA_ENABLE_STAT
 	/* update statistical variables */
 	xma->stat.nused--;
 	xma->stat.alloc -= blk->size;
+#endif
 
 	if ((blk->b.prev && blk->b.prev->avail) &&
 	    (blk->b.next && blk->b.next->avail))
@@ -304,17 +401,19 @@ void qse_xma_free (qse_xma_t* xma, void* b)
 		qse_xma_blk_t* z = y->b.next;
 		qse_size_t bs = blk->size + HDRSIZE + y->size + HDRSIZE;
 
-		detach_block_from_freelist (xma, x);
-		detach_block_from_freelist (xma, y);
+		detach_from_freelist (xma, x);
+		detach_from_freelist (xma, y);
 
 		x->size += bs;
 		x->b.next = z;
 		if (z) z->b.prev = x;	
 
-		attach_block_to_freelist (xma, x);
+		attach_to_freelist (xma, x);
 
+#ifdef QSE_XMA_ENABLE_STAT
 		xma->stat.nfree--;
 		xma->stat.avail += bs;
+#endif
 	}
 	else if (blk->b.next && blk->b.next->avail)
 	{
@@ -344,7 +443,7 @@ void qse_xma_free (qse_xma_t* xma, void* b)
 		qse_size_t bs = x->size + HDRSIZE;
 
 		/* detach x from the free list */
-		detach_block_from_freelist (xma, x);
+		detach_from_freelist (xma, x);
 
 		/* update the block availability */
 		blk->avail = 1;
@@ -357,9 +456,11 @@ void qse_xma_free (qse_xma_t* xma, void* b)
 		blk->b.next = y;
 
 		/* attach blk to the free list */
-		attach_block_to_freelist (xma, blk);
+		attach_to_freelist (xma, blk);
 
+#ifdef QSE_XMA_ENABLE_STAT
 		xma->stat.avail += bs;
+#endif
 	}
 	else if (blk->b.prev && blk->b.prev->avail)
 	{
@@ -389,26 +490,31 @@ void qse_xma_free (qse_xma_t* xma, void* b)
 		qse_xma_blk_t* y = blk->b.next;
 		qse_size_t bs = blk->size + HDRSIZE;
 
-		detach_block_from_freelist (xma, x);
+		detach_from_freelist (xma, x);
 
-		x->size += blk->size + HDRSIZE;
+		x->size += bs;
 		x->b.next = y;
 		if (y) y->b.prev = x;
 
-		attach_block_to_freelist (xma, x);
+		attach_to_freelist (xma, x);
 
+#ifdef QSE_XMA_ENABLE_STAT
 		xma->stat.avail += bs;
+#endif
 	}
 	else
 	{
 		blk->avail = 1;
-		attach_block_to_freelist (xma, blk);
+		attach_to_freelist (xma, blk);
 
+#ifdef QSE_XMA_ENABLE_STAT
 		xma->stat.nfree++;
 		xma->stat.avail += blk->size;
+#endif
 	}
 }
 
+#if 0
 void qse_xma_dump (qse_xma_t* xma)
 {
 	qse_xma_blk_t* tmp;
@@ -438,7 +544,6 @@ void qse_xma_dump (qse_xma_t* xma)
 	printf ("Total           : %18llu bytes\n", asum + fsum + isum);
 }
 
-#if 0
 int main ()
 {
 	int i;
diff --git a/qse/regress/awk/regress.sh b/qse/regress/awk/regress.sh
index 62e7fe73..0e675c28 100755
--- a/qse/regress/awk/regress.sh
+++ b/qse/regress/awk/regress.sh
@@ -48,6 +48,8 @@ print_usage()
 TMPFILE="${TMPFILE:=./regress.temp}"
 OUTFILE="${OUTFILE:=./regress.out}"
 
+GLOBALOPTS="-m 500000"
+
 PROGS="
 	cou-001.awk!cou.dat!!
 	cou-002.awk!cou.dat!!
@@ -198,8 +200,8 @@ run_scripts()
 	
 		[ -z "${redinfile}" ] && redinfile="/dev/stdin"
 
-		echo_title "${valgrind} ${QSEAWK} ${awkopts} -f ${orgscript} ${datafile} <${redinfile} 2>&1"
-		${valgrind} ${QSEAWK} -o "${script}.dp" ${awkopts} -f ${script} ${datafile} <${redinfile} 2>&1
+		echo_title "${valgrind} ${QSEAWK} ${GLOBALOPTS} ${awkopts} -f ${orgscript} ${datafile} <${redinfile} 2>&1"
+		${valgrind} ${QSEAWK} ${GLOBALOPTS} -o "${script}.dp" ${awkopts} -f ${script} ${datafile} <${redinfile} 2>&1
 	
 	done < "${TMPFILE}" 
 	
diff --git a/qse/regress/sed/regress.sh b/qse/regress/sed/regress.sh
index a1aa6363..85abd7aa 100755
--- a/qse/regress/sed/regress.sh
+++ b/qse/regress/sed/regress.sh
@@ -48,6 +48,8 @@ print_usage()
 TMPFILE="${TMPFILE:=./regress.temp}"
 OUTFILE="${OUTFILE:=./regress.out}"
 
+GLOBALOPTS="-m 500000"
+
 PROGS="
 	s001.sed/s001.dat//-n
 	s002.sed/s002.dat//
@@ -85,8 +87,8 @@ run_scripts()
 	
 		[ -z "${redinfile}" ] && redinfile="/dev/stdin"
 
-		echo_title "${valgrind} ${QSESED} ${options} -f ${script} ${datafile} <${redinfile} 2>&1"
-		${valgrind} ${QSESED} ${options} -f ${script} ${datafile} <${redinfile} 2>&1
+		echo_title "${valgrind} ${QSESED} ${GLOBALOPTS} ${options} -f ${script} ${datafile} <${redinfile} 2>&1"
+		${valgrind} ${QSESED} ${GLOBALOPTS} ${options} -f ${script} ${datafile} <${redinfile} 2>&1
 	
 	done < "${TMPFILE}"