pmap_is_modified(9) [freebsd man page]

PMAP_IS_MODIFIED(9)					   BSD Kernel Developer's Manual				       PMAP_IS_MODIFIED(9)

NAME

     pmap_is_modified, pmap_ts_modified -- return information about physical pages

SYNOPSIS

     #include <sys/param.h>
     #include <vm/vm.h>
     #include <vm/pmap.h>

     boolean_t
     pmap_is_modified(vm_page_t m);

     int
     pmap_ts_referenced(vm_page_t m);

DESCRIPTION

     The pmap_is_modified() and pmap_ts_referenced() functions return information about physical pages.

RETURN VALUES

     The pmap_is_modified() function returns the status of the ``page modified'' bit for the physical page m.

     The pmap_ts_referenced() function returns a count of reference bits for a page m, clearing those bits.  It is not necessary for every refer-
     ence bit to be cleared, but it is necessary that 0 only be returned when there are no remaining reference bits set on the page.

SEE ALSO

     pmap(9), pmap_clear_modify(9)

AUTHORS

     This manual page was written by Bruce M Simpson <bms@spc.org>.

BSD
								   July 17, 2014							       BSD

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