}
/*
+ * Holding a page keeps it from being reused. Other parts of the system
+ * can still disassociate the page from its current object and free it, or
+ * perform read or write I/O on it and/or otherwise manipulate the page,
+ * but if the page is held the VM system will leave the page and its data
+ * intact and not reuse the page for other purposes until the last hold
+ * reference is released. (see vm_page_wire() if you want to prevent the
+ * page from being disassociated from its object too).
+ *
+ * The caller must hold vm_token.
+ *
+ * The caller must still validate the contents of the page and, if necessary,
+ * wait for any pending I/O (e.g. vm_page_sleep_busy() loop) to complete
+ * before manipulating the page.
+ */
+void
+vm_page_hold(vm_page_t m)
+{
+ ASSERT_LWKT_TOKEN_HELD(&vm_token);
+ ++m->hold_count;
+}
+
+/*
* The opposite of vm_page_hold(). A page can be freed while being held,
* which places it on the PQ_HOLD queue. We must call vm_page_free_toq()
* in this case to actually free it once the hold count drops to 0.
*
- * This routine must be called at splvm().
+ * The caller must hold vm_token if non-blocking operation is desired,
+ * but otherwise does not need to.
*/
void
-vm_page_unhold(vm_page_t mem)
+vm_page_unhold(vm_page_t m)
{
- --mem->hold_count;
- KASSERT(mem->hold_count >= 0, ("vm_page_unhold: hold count < 0!!!"));
- if (mem->hold_count == 0 && mem->queue == PQ_HOLD) {
- vm_page_busy(mem);
- vm_page_free_toq(mem);
+ lwkt_gettoken(&vm_token);
+ --m->hold_count;
+ KASSERT(m->hold_count >= 0, ("vm_page_unhold: hold count < 0!!!"));
+ if (m->hold_count == 0 && m->queue == PQ_HOLD) {
+ vm_page_busy(m);
+ vm_page_free_toq(m);
}
+ lwkt_reltoken(&vm_token);
}
/*
- * Inserts the given mem entry into the object and object list.
+ * Inserts the given vm_page into the object and object list.
*
* The pagetables are not updated but will presumably fault the page
* in if necessary, or if a kernel page the caller will at some point
* here so we *can't* do this anyway.
*
* This routine may not block.
+ * This routine must be called with the vm_token held.
* This routine must be called with a critical section held.
*/
void
vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex)
{
ASSERT_IN_CRIT_SECTION();
+ ASSERT_LWKT_TOKEN_HELD(&vm_token);
if (m->object != NULL)
panic("vm_page_insert: already inserted");
* Locate and return the page at (object, pindex), or NULL if the
* page could not be found.
*
- * This routine will operate properly without spl protection, but
- * the returned page could be in flux if it is busy. Because an
- * interrupt can race a caller's busy check (unbusying and freeing the
- * page we return before the caller is able to check the busy bit),
- * the caller should generally call this routine with a critical
- * section held.
- *
- * Callers may call this routine without spl protection if they know
- * 'for sure' that the page will not be ripped out from under them
- * by an interrupt.
+ * The caller must hold vm_token if non-blocking operation is desired.
*/
vm_page_t
vm_page_lookup(vm_object_t object, vm_pindex_t pindex)
* is being moved between queues or otherwise is to remain BUSYied by the
* caller.
*
- * This routine must be called at splhigh().
+ * The caller must hold vm_token
* This routine may not block.
*/
void
int queue = m->queue;
struct vpgqueues *pq;
+ ASSERT_LWKT_TOKEN_HELD(&vm_token);
if (queue != PQ_NONE) {
pq = &vm_page_queues[queue];
m->queue = PQ_NONE;
* vm_page_unqueue() - Remove a page from its queue, wakeup the pagedemon
* if necessary.
*
- * This routine must be called at splhigh().
+ * The caller must hold vm_token
* This routine may not block.
*/
void
int queue = m->queue;
struct vpgqueues *pq;
+ ASSERT_LWKT_TOKEN_HELD(&vm_token);
if (queue != PQ_NONE) {
m->queue = PQ_NONE;
pq = &vm_page_queues[queue];
* caches. We need this optimization because cpu caches tend to be
* physical caches, while object spaces tend to be virtual.
*
- * This routine must be called at splvm().
+ * Must be called with vm_token held.
* This routine may not block.
*
* Note that this routine is carefully inlined. A non-inlined version
return(m);
}
+/*
+ * Must be called with vm_token held if the caller desired non-blocking
+ * operation and a stable result.
+ */
vm_page_t
vm_page_list_find(int basequeue, int index, boolean_t prefer_zero)
{
* might be found, but not applicable, they are deactivated. This
* keeps us from using potentially busy cached pages.
*
- * This routine must be called with a critical section held.
* This routine may not block.
+ * Must be called with vm_token held.
*/
vm_page_t
vm_page_select_cache(vm_object_t object, vm_pindex_t pindex)
{
vm_page_t m;
+ ASSERT_LWKT_TOKEN_HELD(&vm_token);
while (TRUE) {
m = _vm_page_list_find(
PQ_CACHE,
* mappings.
*
* Must be called with a critical section held.
+ * Must be called with vm_token held.
*/
void
vm_page_unmanage(vm_page_t m)
{
ASSERT_IN_CRIT_SECTION();
+ ASSERT_LWKT_TOKEN_HELD(&vm_token);
if ((m->flags & PG_UNMANAGED) == 0) {
if (m->wire_count == 0)
vm_page_unqueue(m);
* except without unmapping it from the process address space.
*
* This routine may not block.
+ * The caller must hold vm_token.
*/
static __inline void
_vm_page_deactivate(vm_page_t m, int athead)
}
}
+/*
+ * Attempt to deactivate a page.
+ *
+ * No requirements.
+ */
void
vm_page_deactivate(vm_page_t m)
{
- crit_enter();
- lwkt_gettoken(&vm_token);
- _vm_page_deactivate(m, 0);
- lwkt_reltoken(&vm_token);
- crit_exit();
+ crit_enter();
+ lwkt_gettoken(&vm_token);
+ _vm_page_deactivate(m, 0);
+ lwkt_reltoken(&vm_token);
+ crit_exit();
}
/*
- * vm_page_try_to_cache:
- *
+ * Attempt to move a page to PQ_CACHE.
* Returns 0 on failure, 1 on success
+ *
+ * No requirements.
*/
int
vm_page_try_to_cache(vm_page_t m)
/*
* Attempt to free the page. If we cannot free it, we do nothing.
* 1 is returned on success, 0 on failure.
+ *
+ * No requirements.
*/
int
vm_page_try_to_free(vm_page_t m)
*
* Put the specified page onto the page cache queue (if appropriate).
*
+ * The caller must hold vm_token.
* This routine may not block.
*/
void
vm_page_cache(vm_page_t m)
{
ASSERT_IN_CRIT_SECTION();
+ ASSERT_LWKT_TOKEN_HELD(&vm_token);
if ((m->flags & (PG_BUSY|PG_UNMANAGED)) || m->busy ||
m->wire_count || m->hold_count) {
* system to balance the queues, potentially recovering other unrelated
* space from active. The idea is to not force this to happen too
* often.
+ *
+ * No requirements.
*/
void
vm_page_dontneed(vm_page_t m)
* This routine may be called from mainline code without spl protection and
* be guarenteed a busied page associated with the object at the specified
* index.
+ *
+ * No requirements.
*/
vm_page_t
vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags)
* a page. May not block.
*
* Inputs are required to range within a page.
+ *
+ * No requirements.
+ * Non blocking.
*/
-__inline int
+int
vm_page_bits(int base, int size)
{
int first_bit;
* We set valid bits inclusive of any overlap, but we can only
* clear dirty bits for DEV_BSIZE chunks that are fully within
* the range.
+ *
+ * Page must be busied?
+ * No other requirements.
*/
void
vm_page_set_valid(vm_page_t m, int base, int size)
* NOTE: This function does not clear the pmap modified bit.
* Also note that e.g. NFS may use a byte-granular base
* and size.
+ *
+ * Page must be busied?
+ * No other requirements.
*/
void
vm_page_set_validclean(vm_page_t m, int base, int size)
/*
* Set valid & dirty. Used by buwrite()
+ *
+ * Page must be busied?
+ * No other requirements.
*/
void
vm_page_set_validdirty(vm_page_t m, int base, int size)
* NOTE: This function does not clear the pmap modified bit.
* Also note that e.g. NFS may use a byte-granular base
* and size.
+ *
+ * Page must be busied?
+ * No other requirements.
*/
void
vm_page_clear_dirty(vm_page_t m, int base, int size)
*
* Also make sure the related object and vnode reflect the fact that the
* object may now contain a dirty page.
+ *
+ * Page must be busied?
+ * No other requirements.
*/
void
vm_page_dirty(vm_page_t m)
* Invalidates DEV_BSIZE'd chunks within a page. Both the
* valid and dirty bits for the effected areas are cleared.
*
- * May not block.
+ * Page must be busied?
+ * Does not block.
+ * No other requirements.
*/
void
vm_page_set_invalid(vm_page_t m, int base, int size)
*
* Pages are most often semi-valid when the end of a file is mapped
* into memory and the file's size is not page aligned.
+ *
+ * Page must be busied?
+ * No other requirements.
*/
void
vm_page_zero_invalid(vm_page_t m, boolean_t setvalid)
* will return FALSE in the degenerate case where the page is entirely
* invalid, and TRUE otherwise.
*
- * May not block.
+ * Does not block.
+ * No other requirements.
*/
int
vm_page_is_valid(vm_page_t m, int base, int size)
/*
* update dirty bits from pmap/mmu. May not block.
+ *
+ * Caller must hold vm_token if non-blocking operation desired.
+ * No other requirements.
*/
void
vm_page_test_dirty(vm_page_t m)
static __inline void
vm_page_busy(vm_page_t m)
{
+ ASSERT_LWKT_TOKEN_HELD(&vm_token);
KASSERT((m->flags & PG_BUSY) == 0,
("vm_page_busy: page already busy!!!"));
vm_page_flag_set(m, PG_BUSY);
#define VM_ALLOC_QUICK 0x10 /* like NORMAL but do not use cache */
#define VM_ALLOC_RETRY 0x80 /* indefinite block (vm_page_grab()) */
-void vm_page_unhold(vm_page_t mem);
+void vm_page_hold(vm_page_t);
+void vm_page_unhold(vm_page_t);
void vm_page_activate (vm_page_t);
vm_page_t vm_page_alloc (struct vm_object *, vm_pindex_t, int);
vm_page_t vm_page_grab (struct vm_object *, vm_pindex_t, int);
void vm_page_dirty(vm_page_t m);
/*
- * Holding a page keeps it from being reused. Other parts of the system
- * can still disassociate the page from its current object and free it, or
- * perform read or write I/O on it and/or otherwise manipulate the page,
- * but if the page is held the VM system will leave the page and its data
- * intact and not reuse the page for other purposes until the last hold
- * reference is released. (see vm_page_wire() if you want to prevent the
- * page from being disassociated from its object too).
- *
- * This routine must be called while at splvm() or better.
- *
- * The caller must still validate the contents of the page and, if necessary,
- * wait for any pending I/O (e.g. vm_page_sleep_busy() loop) to complete
- * before manipulating the page.
- */
-static __inline void
-vm_page_hold(vm_page_t mem)
-{
- mem->hold_count++;
-}
-
-/*
* Reduce the protection of a page. This routine never raises the
* protection and therefore can be safely called if the page is already
* at VM_PROT_NONE (it will be a NOP effectively ).
projects / dragonfly.git / commitdiff