vm_page_wire(9) [debian man page]

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

NAME

     vm_page_wire, vm_page_unwire -- wire and unwire pages

SYNOPSIS

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

     void
     vm_page_wire(vm_page_t m);

     void
     vm_page_unwire(vm_page_t m, int activate);

DESCRIPTION

     The vm_page_wire() function increments the wire count on a page, and removes it from whatever queue it is on.

     The vm_page_unwire() function releases one of the wirings on the page.  When write_count reaches zero the page is placed back onto either the
     active queue (if activate is non-zero) or onto the inactive queue (if activate is zero).  If the page is unmanaged (PG_UNMANAGED is set) then
     the page is left on PQ_NONE.

AUTHORS

     This manual page was written by Chad David <davidc@acns.ab.ca>.

BSD
								   July 13, 2001							       BSD

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

NAME

     vm_page_hold, vm_page_unhold -- update a page's hold count

SYNOPSIS

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

     void
     vm_page_hold(vm_page_t m);

     void
     vm_page_unhold(vm_page_t m);

DESCRIPTION

     The vm_page_hold() function increases the hold count on a page.  This prevents the page daemon from freeing the page.

     vm_page_hold() should only be used for very temporary wiring of a page, as that page will not be considered for paging or reallocation for as
     long as its hold count is greater than zero.  Also note that while wired pages are removed from whatever queue they are on, vm_page_hold()
     does not affect the location of the page.	If it is on a queue prior to the call, it will still be there afterward.

     If the page needs to be held for a long period of time, vm_page_wire(9) should be used.

     vm_page_unhold() function reduces the hold count on a page.  If the hold count is zero it is possible that the page will be freed by the page
     daemon.

SEE ALSO

     vm_page_unwire(9), vm_page_wire(9)

AUTHORS

     This manual page was written by Chad David <davidc@acns.ab.ca>.

BSD
								   July 13, 2001							       BSD