skel
Section: VM Functions (9)
Updated: $Date:$
Page Index
NAME
MAP_NR - get memory map index for page in kernel memory
SYNOPSIS
#include <linux/mm.h>
#define MAP_NR(page)
-
DESCRIPTION
This macro maps the page of kernel memory to an index into the
mem_map
array. The input page is kernel-space page addresses such as those
that come from the
get_free_page(9)
function. The expression
mem_map[MAP_NR(page)]
returns a pointer to a
mem_map_t
for the page in question.
Device drivers need access to the page structure if it is implimenting
some special kind of memory segment, i.e. cache for a virtual frame buffer.
RETURN VALUE
Returns an index into the
mem_map
array.
AVAILABILITY
Linux 2.0+
SEE ALSO
get_free_pages(9)
/usr/include/asm/page.h
AUTHOR
Stephen Williams <steve@icarus.com>
BUGS
There is no check that the page you are passing really is a valid page
address.