PMAP_INIT(9) BSD Kernel Developer's Manual PMAP_INIT(9)NAME
pmap_init, pmap_init2 -- initialize the pmap subsystem
SYNOPSIS
#include <sys/param.h>
#include <vm/vm.h>
#include <vm/pmap.h>
void
pmap_init(void);
void
pmap_init2(void);
DESCRIPTION
The pmap_init() function initializes the pmap(9) sub-system. It is called during system initialization by vm_init(), to initialize any
structures that the pmap_init system needs in order to map between physical and virtual memory.
The pmap_init2() function initializes a zone for the PV entries. These are used to implement page sharing at the physical level. A high
water mark is set so that the system can recover from excessive numbers of PV entries.
SEE ALSO pmap(9)AUTHORS
This manual page was written by Bruce M Simpson <bms@spc.org>.
BSD June 10, 2005 BSD
Check Out this Related Man Page
PMAP_EXTRACT(9) BSD Kernel Developer's Manual PMAP_EXTRACT(9)NAME
pmap_extract, pmap_extract_and_hold -- map a virtual address to a physical page
SYNOPSIS
#include <sys/param.h>
#include <vm/vm.h>
#include <vm/pmap.h>
vm_paddr_t
pmap_extract(pmap_t pmap, vm_offset_t va);
vm_paddr_t
pmap_extract_and_hold(pmap_t pmap, vm_offset_t va, vm_prot_t prot);
DESCRIPTION
The pmap_extract() function maps a virtual address to a physical page. In certain situations, callers may use pmap_extract_and_hold()
instead, to ensure that the returned page is held.
The pmap_extract_and_hold() function maps a virtual address to a physical page, and atomically holds the returned page for use by the caller,
only if the mapping permits the given page protection.
IMPLEMENTATION NOTES
Currently, the page protection requested by the caller is not verified.
RETURN VALUES
The pmap_extract() function will return the physical page address associated with the virtual address va inside the physical map pmap. If
the mapping does not exist, or if the pmap parameter is NULL, then NULL will be returned.
The pmap_extract_and_hold() function will return the physical page address associated with the virtual address va inside the physical map
pmap. If the mapping does not exist, the result is a no-op, and NULL will be returned.
SEE ALSO mutex(9), pmap(9)AUTHORS
The pmap_extract_and_hold() function was implemented by Alan L. Cox <alc@imimic.com>. This manual page was written by Bruce M Simpson
<bms@spc.org>.
BSD July 21, 2003 BSD
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