VM_PAGE_FREE(9) BSD Kernel Developer's Manual VM_PAGE_FREE(9)NAME
vm_page_free, vm_page_free_toq, vm_page_free_zero, vm_page_try_to_free —
free a page
SYNOPSIS
#include <sys/param.h>
#include <vm/vm.h>
#include <vm/vm_page.h>
void
vm_page_free(vm_page_t m);
void
vm_page_free_toq(vm_page_t m);
void
vm_page_free_zero(vm_page_t m);
int
vm_page_try_to_free(vm_page_t m);
DESCRIPTION
The vm_page_free_toq() function moves a page into the free queue, and
disassociates it from its object. If the page is held, wired, already
free, or its busy count is not zero, the system will panic. If the
PG_ZERO flag is set on the page, it is placed at the end of the free
queue; otherwise, it is placed at the front.
If the page's object is of type OBJT_VNODE and it is the last page asso‐
ciated with the object, the underlying vnode may be freed.
The vm_page_free() and vm_page_free_zero() functions both call
vm_page_free_toq() to actually free the page, but vm_page_free_zero()
sets the PG_ZERO flag and vm_page_free() clears the PG_ZERO flag prior to
the call to vm_page_free_toq().
The vm_page_try_to_free() function verifies that the page is not held,
wired, busy or dirty, and if so, marks the page as busy, drops any pro‐
tection that may be set on the page, and frees it.
RETURN VALUESvm_page_try_to_free() returns 1 if it is able to free the page; other‐
wise, 0 is returned.
SEE ALSOvm_page_busy(9), vm_page_hold(9), vm_page_wire(9)AUTHORS
This manual page was written by Chad David ⟨davidc@acns.ab.ca⟩.
BSD July 24, 2001 BSD
