--- ./drivers/ide/ide-probe.c.~1~	Fri Mar 29 13:35:36 2002
+++ ./drivers/ide/ide-probe.c	Fri Mar 29 16:30:51 2002
@@ -813,7 +813,10 @@
 		 * IDE can do up to 128K per request == 256
 		 */
 		*max_sect++ = ((hwif->chipset == ide_pdc4030) ? 127 : 128);
-		*max_ra++ = vm_max_readahead;
+		*max_ra = (128 >> (PAGE_SHIFT - 10)) - 1; /* sequential read with 128k large DMA */
+		if (hwif->chipset == ide_pdc4030)
+			*max_ra = (127 >> (PAGE_SHIFT - 10)) - 1; /* sequential read with 127k large DMA */
+		max_ra++;
 	}
 
 	for (unit = 0; unit < units; ++unit)
--- ./mm/filemap.c.~1~	Fri Mar 29 15:58:52 2002
+++ ./mm/filemap.c	Fri Mar 29 16:27:21 2002
@@ -46,7 +46,7 @@
 unsigned int page_hash_bits;
 struct page **page_hash_table;
 
-int vm_max_readahead = 31;
+int vm_max_readahead = (512 >> (PAGE_SHIFT - 10)) - 1; /* sequential read with 512k large DMA */
 int vm_min_readahead = 3;
 EXPORT_SYMBOL(vm_max_readahead);
 EXPORT_SYMBOL(vm_min_readahead);