The "len" parameter (4th arg) of get_user_pages() is in pages, not
bytes.  The effect of this bug is that if you migrate a page, and
if this page is followed by valid virtual addresses, but these 
pages have not yet been touched and allocated, then the migration
call will cause those pages to be touched and allocated.  The number
of pages so effected is the min of (16384, the remaining number of
pages in the vma, the number of pages required to fill out the
current pmd).

Signed-off-by: Ray Bryant <raybry@sgi.com>

Index: linux/mm/rmap.c
===================================================================
--- linux.orig/mm/rmap.c	2005-01-30 10:34:03.000000000 -0800
+++ linux/mm/rmap.c	2005-02-28 08:53:30.000000000 -0800
@@ -554,8 +554,7 @@ touch_unmapped_address(struct list_head 
 		vma = find_vma(v1->mm, v1->addr);
 		if (vma == NULL)
 			goto out;
-		error = get_user_pages(current, v1->mm, v1->addr, PAGE_SIZE,
-					0, 0, NULL, NULL);
+		error = get_user_pages(current, v1->mm, v1->addr, 1, 0, 0, NULL, NULL);
 		if (error < 0)
 			ret = error;
 	out: