Differential D46944 Diff 144441 sys/vm/vm_page.c

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sys/vm/vm_page.c

Show First 20 Lines • Show All 4,269 Lines • ▼ Show 20 Lines	vm_page_unwire_managed(vm_page_t m, uint8_t nqueue, bool noreuse)

/*		/*
* Update LRU state before releasing the wiring reference.		* Update LRU state before releasing the wiring reference.
* Use a release store when updating the reference count to		* Use a release store when updating the reference count to
* synchronize with vm_page_free_prep().		* synchronize with vm_page_free_prep().
*/		*/
old = atomic_load_int(&m->ref_count);		old = atomic_load_int(&m->ref_count);
do {		do {
		u_int count;

KASSERT(VPRC_WIRE_COUNT(old) > 0,		KASSERT(VPRC_WIRE_COUNT(old) > 0,
("vm_page_unwire: wire count underflow for page %p", m));		("vm_page_unwire: wire count underflow for page %p", m));

if (old > VPRC_OBJREF + 1) {		count = old & ~VPRC_BLOCKED;
		if (count > VPRC_OBJREF + 1) {
/*		/*
* The page has at least one other wiring reference. An		* The page has at least one other wiring reference. An
* earlier iteration of this loop may have called		* earlier iteration of this loop may have called
* vm_page_release_toq() and cleared PGA_DEQUEUE, so		* vm_page_release_toq() and cleared PGA_DEQUEUE, so
* re-set it if necessary.		* re-set it if necessary.
*/		*/
if ((vm_page_astate_load(m).flags & PGA_DEQUEUE) == 0)		if ((vm_page_astate_load(m).flags & PGA_DEQUEUE) == 0)
vm_page_aflag_set(m, PGA_DEQUEUE);		vm_page_aflag_set(m, PGA_DEQUEUE);
} else if (old == VPRC_OBJREF + 1) {		} else if (count == VPRC_OBJREF + 1) {
/*		/*
* This is the last wiring. Clear PGA_DEQUEUE and		* This is the last wiring. Clear PGA_DEQUEUE and
* update the page's queue state to reflect the		* update the page's queue state to reflect the
* reference. If the page does not belong to an object		* reference. If the page does not belong to an object
* (i.e., the VPRC_OBJREF bit is clear), we only need to		* (i.e., the VPRC_OBJREF bit is clear), we only need to
* clear leftover queue state.		* clear leftover queue state.
*/		*/
vm_page_release_toq(m, nqueue, noreuse);		vm_page_release_toq(m, nqueue, noreuse);
} else if (old == 1) {		} else if (count == 1) {
vm_page_aflag_clear(m, PGA_DEQUEUE);		vm_page_aflag_clear(m, PGA_DEQUEUE);
}		}
} while (!atomic_fcmpset_rel_int(&m->ref_count, &old, old - 1));		} while (!atomic_fcmpset_rel_int(&m->ref_count, &old, old - 1));

if (VPRC_WIRE_COUNT(old) == 1) {		if (VPRC_WIRE_COUNT(old) == 1) {
vm_wire_sub(1);		vm_wire_sub(1);
if (old == 1)		if (old == 1)
vm_page_free(m);		vm_page_free(m);
▲ Show 20 Lines • Show All 259 Lines • ▼ Show 20 Lines	vm_page_try_blocked_op(vm_page_t m, void (*op)(vm_page_t))
KASSERT(vm_page_busied(m),		KASSERT(vm_page_busied(m),
("vm_page_try_blocked_op: page %p is not busy", m));		("vm_page_try_blocked_op: page %p is not busy", m));
VM_OBJECT_ASSERT_LOCKED(m->object);		VM_OBJECT_ASSERT_LOCKED(m->object);

old = atomic_load_int(&m->ref_count);		old = atomic_load_int(&m->ref_count);
do {		do {
KASSERT(old != 0,		KASSERT(old != 0,
("vm_page_try_blocked_op: page %p has no references", m));		("vm_page_try_blocked_op: page %p has no references", m));
		KASSERT((old & VPRC_BLOCKED) == 0,
		("vm_page_try_blocked_op: page %p blocks wirings", m));
if (VPRC_WIRE_COUNT(old) != 0)		if (VPRC_WIRE_COUNT(old) != 0)
return (false);		return (false);
} while (!atomic_fcmpset_int(&m->ref_count, &old, old \| VPRC_BLOCKED));		} while (!atomic_fcmpset_int(&m->ref_count, &old, old \| VPRC_BLOCKED));

(op)(m);		(op)(m);

/*		/*
* If the object is read-locked, new wirings may be created via an		* If the object is read-locked, new wirings may be created via an
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