4 * Copyright (c) 1991 Regents of the University of California.
7 * This code is derived from software contributed to Berkeley by
8 * The Mach Operating System project at Carnegie-Mellon University.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * from: @(#)vm_page.c 7.4 (Berkeley) 5/7/91
39 * $FreeBSD: src/sys/vm/vm_page.c,v 1.147.2.18 2002/03/10 05:03:19 alc Exp $
40 * $DragonFly: src/sys/vm/vm_page.c,v 1.40 2008/08/25 17:01:42 dillon Exp $
44 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
45 * All rights reserved.
47 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
49 * Permission to use, copy, modify and distribute this software and
50 * its documentation is hereby granted, provided that both the copyright
51 * notice and this permission notice appear in all copies of the
52 * software, derivative works or modified versions, and any portions
53 * thereof, and that both notices appear in supporting documentation.
55 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
56 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
57 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
59 * Carnegie Mellon requests users of this software to return to
61 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
62 * School of Computer Science
63 * Carnegie Mellon University
64 * Pittsburgh PA 15213-3890
66 * any improvements or extensions that they make and grant Carnegie the
67 * rights to redistribute these changes.
70 * Resident memory management module. The module manipulates 'VM pages'.
71 * A VM page is the core building block for memory management.
74 #include <sys/param.h>
75 #include <sys/systm.h>
76 #include <sys/malloc.h>
78 #include <sys/vmmeter.h>
79 #include <sys/vnode.h>
82 #include <vm/vm_param.h>
84 #include <vm/vm_kern.h>
86 #include <vm/vm_map.h>
87 #include <vm/vm_object.h>
88 #include <vm/vm_page.h>
89 #include <vm/vm_pageout.h>
90 #include <vm/vm_pager.h>
91 #include <vm/vm_extern.h>
92 #include <vm/swap_pager.h>
94 #include <machine/md_var.h>
96 #include <vm/vm_page2.h>
97 #include <sys/mplock2.h>
99 #define VMACTION_HSIZE 256
100 #define VMACTION_HMASK (VMACTION_HSIZE - 1)
102 static void vm_page_queue_init(void);
103 static void vm_page_free_wakeup(void);
104 static vm_page_t vm_page_select_cache(vm_object_t, vm_pindex_t);
105 static vm_page_t _vm_page_list_find2(int basequeue, int index);
107 struct vpgqueues vm_page_queues[PQ_COUNT]; /* Array of tailq lists */
109 LIST_HEAD(vm_page_action_list, vm_page_action);
110 struct vm_page_action_list action_list[VMACTION_HSIZE];
113 #define ASSERT_IN_CRIT_SECTION() KKASSERT(crit_test(curthread));
115 RB_GENERATE2(vm_page_rb_tree, vm_page, rb_entry, rb_vm_page_compare,
116 vm_pindex_t, pindex);
119 vm_page_queue_init(void)
123 for (i = 0; i < PQ_L2_SIZE; i++)
124 vm_page_queues[PQ_FREE+i].cnt = &vmstats.v_free_count;
125 for (i = 0; i < PQ_L2_SIZE; i++)
126 vm_page_queues[PQ_CACHE+i].cnt = &vmstats.v_cache_count;
128 vm_page_queues[PQ_INACTIVE].cnt = &vmstats.v_inactive_count;
129 vm_page_queues[PQ_ACTIVE].cnt = &vmstats.v_active_count;
130 vm_page_queues[PQ_HOLD].cnt = &vmstats.v_active_count;
131 /* PQ_NONE has no queue */
133 for (i = 0; i < PQ_COUNT; i++)
134 TAILQ_INIT(&vm_page_queues[i].pl);
136 for (i = 0; i < VMACTION_HSIZE; i++)
137 LIST_INIT(&action_list[i]);
141 * note: place in initialized data section? Is this necessary?
144 int vm_page_array_size = 0;
145 int vm_page_zero_count = 0;
146 vm_page_t vm_page_array = 0;
151 * Sets the page size, perhaps based upon the memory size.
152 * Must be called before any use of page-size dependent functions.
155 vm_set_page_size(void)
157 if (vmstats.v_page_size == 0)
158 vmstats.v_page_size = PAGE_SIZE;
159 if (((vmstats.v_page_size - 1) & vmstats.v_page_size) != 0)
160 panic("vm_set_page_size: page size not a power of two");
166 * Add a new page to the freelist for use by the system. New pages
167 * are added to both the head and tail of the associated free page
168 * queue in a bottom-up fashion, so both zero'd and non-zero'd page
169 * requests pull 'recent' adds (higher physical addresses) first.
171 * Must be called in a critical section.
174 vm_add_new_page(vm_paddr_t pa)
176 struct vpgqueues *vpq;
179 ++vmstats.v_page_count;
180 ++vmstats.v_free_count;
181 m = PHYS_TO_VM_PAGE(pa);
184 m->pc = (pa >> PAGE_SHIFT) & PQ_L2_MASK;
185 m->queue = m->pc + PQ_FREE;
186 KKASSERT(m->dirty == 0);
188 vpq = &vm_page_queues[m->queue];
190 TAILQ_INSERT_TAIL(&vpq->pl, m, pageq);
192 TAILQ_INSERT_HEAD(&vpq->pl, m, pageq);
193 vpq->flipflop = 1 - vpq->flipflop;
195 vm_page_queues[m->queue].lcnt++;
202 * Initializes the resident memory module.
204 * Allocates memory for the page cells, and for the object/offset-to-page
205 * hash table headers. Each page cell is initialized and placed on the
208 * starta/enda represents the range of physical memory addresses available
209 * for use (skipping memory already used by the kernel), subject to
210 * phys_avail[]. Note that phys_avail[] has already mapped out memory
211 * already in use by the kernel.
214 vm_page_startup(vm_offset_t vaddr)
218 vm_paddr_t page_range;
225 vm_paddr_t biggestone, biggestsize;
232 vaddr = round_page(vaddr);
234 for (i = 0; phys_avail[i + 1]; i += 2) {
235 phys_avail[i] = round_page64(phys_avail[i]);
236 phys_avail[i + 1] = trunc_page64(phys_avail[i + 1]);
239 for (i = 0; phys_avail[i + 1]; i += 2) {
240 vm_paddr_t size = phys_avail[i + 1] - phys_avail[i];
242 if (size > biggestsize) {
250 end = phys_avail[biggestone+1];
251 end = trunc_page(end);
254 * Initialize the queue headers for the free queue, the active queue
255 * and the inactive queue.
258 vm_page_queue_init();
260 /* VKERNELs don't support minidumps and as such don't need vm_page_dump */
261 #if !defined(_KERNEL_VIRTUAL)
263 * Allocate a bitmap to indicate that a random physical page
264 * needs to be included in a minidump.
266 * The amd64 port needs this to indicate which direct map pages
267 * need to be dumped, via calls to dump_add_page()/dump_drop_page().
269 * However, i386 still needs this workspace internally within the
270 * minidump code. In theory, they are not needed on i386, but are
271 * included should the sf_buf code decide to use them.
273 page_range = phys_avail[(nblocks - 1) * 2 + 1] / PAGE_SIZE;
274 vm_page_dump_size = round_page(roundup2(page_range, NBBY) / NBBY);
275 end -= vm_page_dump_size;
276 vm_page_dump = (void *)pmap_map(&vaddr, end, end + vm_page_dump_size,
277 VM_PROT_READ | VM_PROT_WRITE);
278 bzero((void *)vm_page_dump, vm_page_dump_size);
282 * Compute the number of pages of memory that will be available for
283 * use (taking into account the overhead of a page structure per
286 first_page = phys_avail[0] / PAGE_SIZE;
287 page_range = phys_avail[(nblocks - 1) * 2 + 1] / PAGE_SIZE - first_page;
288 npages = (total - (page_range * sizeof(struct vm_page))) / PAGE_SIZE;
291 * Initialize the mem entry structures now, and put them in the free
294 new_end = trunc_page(end - page_range * sizeof(struct vm_page));
295 mapped = pmap_map(&vaddr, new_end, end,
296 VM_PROT_READ | VM_PROT_WRITE);
297 vm_page_array = (vm_page_t)mapped;
299 #if defined(__x86_64__) && !defined(_KERNEL_VIRTUAL)
301 * since pmap_map on amd64 returns stuff out of a direct-map region,
302 * we have to manually add these pages to the minidump tracking so
303 * that they can be dumped, including the vm_page_array.
305 for (pa = new_end; pa < phys_avail[biggestone + 1]; pa += PAGE_SIZE)
310 * Clear all of the page structures
312 bzero((caddr_t) vm_page_array, page_range * sizeof(struct vm_page));
313 vm_page_array_size = page_range;
316 * Construct the free queue(s) in ascending order (by physical
317 * address) so that the first 16MB of physical memory is allocated
318 * last rather than first. On large-memory machines, this avoids
319 * the exhaustion of low physical memory before isa_dmainit has run.
321 vmstats.v_page_count = 0;
322 vmstats.v_free_count = 0;
323 for (i = 0; phys_avail[i + 1] && npages > 0; i += 2) {
328 last_pa = phys_avail[i + 1];
329 while (pa < last_pa && npages-- > 0) {
338 * Scan comparison function for Red-Black tree scans. An inclusive
339 * (start,end) is expected. Other fields are not used.
342 rb_vm_page_scancmp(struct vm_page *p, void *data)
344 struct rb_vm_page_scan_info *info = data;
346 if (p->pindex < info->start_pindex)
348 if (p->pindex > info->end_pindex)
354 rb_vm_page_compare(struct vm_page *p1, struct vm_page *p2)
356 if (p1->pindex < p2->pindex)
358 if (p1->pindex > p2->pindex)
364 * Holding a page keeps it from being reused. Other parts of the system
365 * can still disassociate the page from its current object and free it, or
366 * perform read or write I/O on it and/or otherwise manipulate the page,
367 * but if the page is held the VM system will leave the page and its data
368 * intact and not reuse the page for other purposes until the last hold
369 * reference is released. (see vm_page_wire() if you want to prevent the
370 * page from being disassociated from its object too).
372 * The caller must hold vm_token.
374 * The caller must still validate the contents of the page and, if necessary,
375 * wait for any pending I/O (e.g. vm_page_sleep_busy() loop) to complete
376 * before manipulating the page.
379 vm_page_hold(vm_page_t m)
381 ASSERT_LWKT_TOKEN_HELD(&vm_token);
386 * The opposite of vm_page_hold(). A page can be freed while being held,
387 * which places it on the PQ_HOLD queue. We must call vm_page_free_toq()
388 * in this case to actually free it once the hold count drops to 0.
390 * The caller must hold vm_token if non-blocking operation is desired,
391 * but otherwise does not need to.
394 vm_page_unhold(vm_page_t m)
396 lwkt_gettoken(&vm_token);
398 KASSERT(m->hold_count >= 0, ("vm_page_unhold: hold count < 0!!!"));
399 if (m->hold_count == 0 && m->queue == PQ_HOLD) {
403 lwkt_reltoken(&vm_token);
407 * Inserts the given vm_page into the object and object list.
409 * The pagetables are not updated but will presumably fault the page
410 * in if necessary, or if a kernel page the caller will at some point
411 * enter the page into the kernel's pmap. We are not allowed to block
412 * here so we *can't* do this anyway.
414 * This routine may not block.
415 * This routine must be called with the vm_token held.
416 * This routine must be called with a critical section held.
419 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex)
421 ASSERT_IN_CRIT_SECTION();
422 ASSERT_LWKT_TOKEN_HELD(&vm_token);
423 if (m->object != NULL)
424 panic("vm_page_insert: already inserted");
427 * Record the object/offset pair in this page
433 * Insert it into the object.
435 vm_page_rb_tree_RB_INSERT(&object->rb_memq, m);
436 object->generation++;
439 * show that the object has one more resident page.
441 object->resident_page_count++;
444 * Add the pv_list_cout of the page when its inserted in
447 object->agg_pv_list_count = object->agg_pv_list_count + m->md.pv_list_count;
450 * Since we are inserting a new and possibly dirty page,
451 * update the object's OBJ_WRITEABLE and OBJ_MIGHTBEDIRTY flags.
453 if ((m->valid & m->dirty) || (m->flags & PG_WRITEABLE))
454 vm_object_set_writeable_dirty(object);
457 * Checks for a swap assignment and sets PG_SWAPPED if appropriate.
459 swap_pager_page_inserted(m);
463 * Removes the given vm_page_t from the global (object,index) hash table
464 * and from the object's memq.
466 * The underlying pmap entry (if any) is NOT removed here.
467 * This routine may not block.
469 * The page must be BUSY and will remain BUSY on return.
470 * No other requirements.
472 * NOTE: FreeBSD side effect was to unbusy the page on return. We leave
476 vm_page_remove(vm_page_t m)
481 lwkt_gettoken(&vm_token);
482 if (m->object == NULL) {
483 lwkt_reltoken(&vm_token);
488 if ((m->flags & PG_BUSY) == 0)
489 panic("vm_page_remove: page not busy");
494 * Remove the page from the object and update the object.
496 vm_page_rb_tree_RB_REMOVE(&object->rb_memq, m);
497 object->resident_page_count--;
498 object->agg_pv_list_count = object->agg_pv_list_count - m->md.pv_list_count;
499 object->generation++;
502 lwkt_reltoken(&vm_token);
507 * Locate and return the page at (object, pindex), or NULL if the
508 * page could not be found.
510 * The caller must hold vm_token.
513 vm_page_lookup(vm_object_t object, vm_pindex_t pindex)
518 * Search the hash table for this object/offset pair
520 ASSERT_LWKT_TOKEN_HELD(&vm_token);
522 m = vm_page_rb_tree_RB_LOOKUP(&object->rb_memq, pindex);
524 KKASSERT(m == NULL || (m->object == object && m->pindex == pindex));
531 * Move the given memory entry from its current object to the specified
532 * target object/offset.
534 * The object must be locked.
535 * This routine may not block.
537 * Note: This routine will raise itself to splvm(), the caller need not.
539 * Note: Swap associated with the page must be invalidated by the move. We
540 * have to do this for several reasons: (1) we aren't freeing the
541 * page, (2) we are dirtying the page, (3) the VM system is probably
542 * moving the page from object A to B, and will then later move
543 * the backing store from A to B and we can't have a conflict.
545 * Note: We *always* dirty the page. It is necessary both for the
546 * fact that we moved it, and because we may be invalidating
547 * swap. If the page is on the cache, we have to deactivate it
548 * or vm_page_dirty() will panic. Dirty pages are not allowed
552 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex)
555 lwkt_gettoken(&vm_token);
557 vm_page_insert(m, new_object, new_pindex);
558 if (m->queue - m->pc == PQ_CACHE)
559 vm_page_deactivate(m);
562 lwkt_reltoken(&vm_token);
567 * vm_page_unqueue() without any wakeup. This routine is used when a page
568 * is being moved between queues or otherwise is to remain BUSYied by the
571 * The caller must hold vm_token
572 * This routine may not block.
575 vm_page_unqueue_nowakeup(vm_page_t m)
577 int queue = m->queue;
578 struct vpgqueues *pq;
580 ASSERT_LWKT_TOKEN_HELD(&vm_token);
581 if (queue != PQ_NONE) {
582 pq = &vm_page_queues[queue];
584 TAILQ_REMOVE(&pq->pl, m, pageq);
591 * vm_page_unqueue() - Remove a page from its queue, wakeup the pagedemon
594 * The caller must hold vm_token
595 * This routine may not block.
598 vm_page_unqueue(vm_page_t m)
600 int queue = m->queue;
601 struct vpgqueues *pq;
603 ASSERT_LWKT_TOKEN_HELD(&vm_token);
604 if (queue != PQ_NONE) {
606 pq = &vm_page_queues[queue];
607 TAILQ_REMOVE(&pq->pl, m, pageq);
610 if ((queue - m->pc) == PQ_CACHE || (queue - m->pc) == PQ_FREE)
616 * vm_page_list_find()
618 * Find a page on the specified queue with color optimization.
620 * The page coloring optimization attempts to locate a page that does
621 * not overload other nearby pages in the object in the cpu's L1 or L2
622 * caches. We need this optimization because cpu caches tend to be
623 * physical caches, while object spaces tend to be virtual.
625 * Must be called with vm_token held.
626 * This routine may not block.
628 * Note that this routine is carefully inlined. A non-inlined version
629 * is available for outside callers but the only critical path is
630 * from within this source file.
634 _vm_page_list_find(int basequeue, int index, boolean_t prefer_zero)
639 m = TAILQ_LAST(&vm_page_queues[basequeue+index].pl, pglist);
641 m = TAILQ_FIRST(&vm_page_queues[basequeue+index].pl);
643 m = _vm_page_list_find2(basequeue, index);
648 _vm_page_list_find2(int basequeue, int index)
652 struct vpgqueues *pq;
654 pq = &vm_page_queues[basequeue];
657 * Note that for the first loop, index+i and index-i wind up at the
658 * same place. Even though this is not totally optimal, we've already
659 * blown it by missing the cache case so we do not care.
662 for(i = PQ_L2_SIZE / 2; i > 0; --i) {
663 if ((m = TAILQ_FIRST(&pq[(index + i) & PQ_L2_MASK].pl)) != NULL)
666 if ((m = TAILQ_FIRST(&pq[(index - i) & PQ_L2_MASK].pl)) != NULL)
673 * Must be called with vm_token held if the caller desired non-blocking
674 * operation and a stable result.
677 vm_page_list_find(int basequeue, int index, boolean_t prefer_zero)
679 return(_vm_page_list_find(basequeue, index, prefer_zero));
683 * Find a page on the cache queue with color optimization. As pages
684 * might be found, but not applicable, they are deactivated. This
685 * keeps us from using potentially busy cached pages.
687 * This routine may not block.
688 * Must be called with vm_token held.
691 vm_page_select_cache(vm_object_t object, vm_pindex_t pindex)
695 ASSERT_LWKT_TOKEN_HELD(&vm_token);
697 m = _vm_page_list_find(
699 (pindex + object->pg_color) & PQ_L2_MASK,
702 if (m && ((m->flags & (PG_BUSY|PG_UNMANAGED)) || m->busy ||
703 m->hold_count || m->wire_count)) {
704 vm_page_deactivate(m);
713 * Find a free or zero page, with specified preference. We attempt to
714 * inline the nominal case and fall back to _vm_page_select_free()
717 * This routine must be called with a critical section held.
718 * This routine may not block.
720 static __inline vm_page_t
721 vm_page_select_free(vm_object_t object, vm_pindex_t pindex, boolean_t prefer_zero)
725 m = _vm_page_list_find(
727 (pindex + object->pg_color) & PQ_L2_MASK,
736 * Allocate and return a memory cell associated with this VM object/offset
741 * VM_ALLOC_NORMAL allow use of cache pages, nominal free drain
742 * VM_ALLOC_QUICK like normal but cannot use cache
743 * VM_ALLOC_SYSTEM greater free drain
744 * VM_ALLOC_INTERRUPT allow free list to be completely drained
745 * VM_ALLOC_ZERO advisory request for pre-zero'd page
747 * The object must be locked.
748 * This routine may not block.
749 * The returned page will be marked PG_BUSY
751 * Additional special handling is required when called from an interrupt
752 * (VM_ALLOC_INTERRUPT). We are not allowed to mess with the page cache
756 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int page_req)
761 lwkt_gettoken(&vm_token);
763 KKASSERT(object != NULL);
764 KASSERT(!vm_page_lookup(object, pindex),
765 ("vm_page_alloc: page already allocated"));
767 (VM_ALLOC_NORMAL|VM_ALLOC_QUICK|
768 VM_ALLOC_INTERRUPT|VM_ALLOC_SYSTEM));
771 * Certain system threads (pageout daemon, buf_daemon's) are
772 * allowed to eat deeper into the free page list.
774 if (curthread->td_flags & TDF_SYSTHREAD)
775 page_req |= VM_ALLOC_SYSTEM;
778 if (vmstats.v_free_count > vmstats.v_free_reserved ||
779 ((page_req & VM_ALLOC_INTERRUPT) && vmstats.v_free_count > 0) ||
780 ((page_req & VM_ALLOC_SYSTEM) && vmstats.v_cache_count == 0 &&
781 vmstats.v_free_count > vmstats.v_interrupt_free_min)
784 * The free queue has sufficient free pages to take one out.
786 if (page_req & VM_ALLOC_ZERO)
787 m = vm_page_select_free(object, pindex, TRUE);
789 m = vm_page_select_free(object, pindex, FALSE);
790 } else if (page_req & VM_ALLOC_NORMAL) {
792 * Allocatable from the cache (non-interrupt only). On
793 * success, we must free the page and try again, thus
794 * ensuring that vmstats.v_*_free_min counters are replenished.
797 if (curthread->td_preempted) {
798 kprintf("vm_page_alloc(): warning, attempt to allocate"
799 " cache page from preempting interrupt\n");
802 m = vm_page_select_cache(object, pindex);
805 m = vm_page_select_cache(object, pindex);
808 * On success move the page into the free queue and loop.
811 KASSERT(m->dirty == 0,
812 ("Found dirty cache page %p", m));
814 vm_page_protect(m, VM_PROT_NONE);
820 * On failure return NULL
822 lwkt_reltoken(&vm_token);
824 #if defined(DIAGNOSTIC)
825 if (vmstats.v_cache_count > 0)
826 kprintf("vm_page_alloc(NORMAL): missing pages on cache queue: %d\n", vmstats.v_cache_count);
828 vm_pageout_deficit++;
833 * No pages available, wakeup the pageout daemon and give up.
835 lwkt_reltoken(&vm_token);
837 vm_pageout_deficit++;
843 * Good page found. The page has not yet been busied. We are in
844 * a critical section.
846 KASSERT(m != NULL, ("vm_page_alloc(): missing page on free queue\n"));
847 KASSERT(m->dirty == 0,
848 ("vm_page_alloc: free/cache page %p was dirty", m));
851 * Remove from free queue
853 vm_page_unqueue_nowakeup(m);
856 * Initialize structure. Only the PG_ZERO flag is inherited. Set
859 if (m->flags & PG_ZERO) {
860 vm_page_zero_count--;
861 m->flags = PG_ZERO | PG_BUSY;
872 * vm_page_insert() is safe prior to the crit_exit(). Note also that
873 * inserting a page here does not insert it into the pmap (which
874 * could cause us to block allocating memory). We cannot block
877 vm_page_insert(m, object, pindex);
880 * Don't wakeup too often - wakeup the pageout daemon when
881 * we would be nearly out of memory.
885 lwkt_reltoken(&vm_token);
889 * A PG_BUSY page is returned.
895 * Wait for sufficient free memory for nominal heavy memory use kernel
899 vm_wait_nominal(void)
901 while (vm_page_count_min(0))
906 * Test if vm_wait_nominal() would block.
909 vm_test_nominal(void)
911 if (vm_page_count_min(0))
917 * Block until free pages are available for allocation, called in various
918 * places before memory allocations.
924 lwkt_gettoken(&vm_token);
925 if (curthread == pagethread) {
926 vm_pageout_pages_needed = 1;
927 tsleep(&vm_pageout_pages_needed, 0, "VMWait", timo);
929 if (vm_pages_needed == 0) {
931 wakeup(&vm_pages_needed);
933 tsleep(&vmstats.v_free_count, 0, "vmwait", timo);
935 lwkt_reltoken(&vm_token);
940 * Block until free pages are available for allocation
942 * Called only in vm_fault so that processes page faulting can be
949 lwkt_gettoken(&vm_token);
950 if (vm_pages_needed == 0) {
952 wakeup(&vm_pages_needed);
954 tsleep(&vmstats.v_free_count, 0, "pfault", 0);
955 lwkt_reltoken(&vm_token);
960 * Put the specified page on the active list (if appropriate). Ensure
961 * that act_count is at least ACT_INIT but do not otherwise mess with it.
963 * The page queues must be locked.
964 * This routine may not block.
967 vm_page_activate(vm_page_t m)
970 lwkt_gettoken(&vm_token);
971 if (m->queue != PQ_ACTIVE) {
972 if ((m->queue - m->pc) == PQ_CACHE)
973 mycpu->gd_cnt.v_reactivated++;
977 if (m->wire_count == 0 && (m->flags & PG_UNMANAGED) == 0) {
978 m->queue = PQ_ACTIVE;
979 vm_page_queues[PQ_ACTIVE].lcnt++;
980 TAILQ_INSERT_TAIL(&vm_page_queues[PQ_ACTIVE].pl,
982 if (m->act_count < ACT_INIT)
983 m->act_count = ACT_INIT;
984 vmstats.v_active_count++;
987 if (m->act_count < ACT_INIT)
988 m->act_count = ACT_INIT;
990 lwkt_reltoken(&vm_token);
995 * Helper routine for vm_page_free_toq() and vm_page_cache(). This
996 * routine is called when a page has been added to the cache or free
999 * This routine may not block.
1000 * This routine must be called at splvm()
1002 static __inline void
1003 vm_page_free_wakeup(void)
1006 * if pageout daemon needs pages, then tell it that there are
1009 if (vm_pageout_pages_needed &&
1010 vmstats.v_cache_count + vmstats.v_free_count >=
1011 vmstats.v_pageout_free_min
1013 wakeup(&vm_pageout_pages_needed);
1014 vm_pageout_pages_needed = 0;
1018 * wakeup processes that are waiting on memory if we hit a
1019 * high water mark. And wakeup scheduler process if we have
1020 * lots of memory. this process will swapin processes.
1022 if (vm_pages_needed && !vm_page_count_min(0)) {
1023 vm_pages_needed = 0;
1024 wakeup(&vmstats.v_free_count);
1031 * Returns the given page to the PQ_FREE list, disassociating it with
1034 * The vm_page must be PG_BUSY on entry. PG_BUSY will be released on
1035 * return (the page will have been freed). No particular spl is required
1038 * This routine may not block.
1041 vm_page_free_toq(vm_page_t m)
1043 struct vpgqueues *pq;
1046 lwkt_gettoken(&vm_token);
1047 mycpu->gd_cnt.v_tfree++;
1049 KKASSERT((m->flags & PG_MAPPED) == 0);
1051 if (m->busy || ((m->queue - m->pc) == PQ_FREE)) {
1053 "vm_page_free: pindex(%lu), busy(%d), PG_BUSY(%d), hold(%d)\n",
1054 (u_long)m->pindex, m->busy, (m->flags & PG_BUSY) ? 1 : 0,
1056 if ((m->queue - m->pc) == PQ_FREE)
1057 panic("vm_page_free: freeing free page");
1059 panic("vm_page_free: freeing busy page");
1063 * unqueue, then remove page. Note that we cannot destroy
1064 * the page here because we do not want to call the pager's
1065 * callback routine until after we've put the page on the
1066 * appropriate free queue.
1068 vm_page_unqueue_nowakeup(m);
1072 * No further management of fictitious pages occurs beyond object
1073 * and queue removal.
1075 if ((m->flags & PG_FICTITIOUS) != 0) {
1077 lwkt_reltoken(&vm_token);
1085 if (m->wire_count != 0) {
1086 if (m->wire_count > 1) {
1088 "vm_page_free: invalid wire count (%d), pindex: 0x%lx",
1089 m->wire_count, (long)m->pindex);
1091 panic("vm_page_free: freeing wired page");
1095 * Clear the UNMANAGED flag when freeing an unmanaged page.
1097 if (m->flags & PG_UNMANAGED) {
1098 m->flags &= ~PG_UNMANAGED;
1101 if (m->hold_count != 0) {
1102 m->flags &= ~PG_ZERO;
1105 m->queue = PQ_FREE + m->pc;
1107 pq = &vm_page_queues[m->queue];
1112 * Put zero'd pages on the end ( where we look for zero'd pages
1113 * first ) and non-zerod pages at the head.
1115 if (m->flags & PG_ZERO) {
1116 TAILQ_INSERT_TAIL(&pq->pl, m, pageq);
1117 ++vm_page_zero_count;
1119 TAILQ_INSERT_HEAD(&pq->pl, m, pageq);
1122 vm_page_free_wakeup();
1123 lwkt_reltoken(&vm_token);
1128 * vm_page_free_fromq_fast()
1130 * Remove a non-zero page from one of the free queues; the page is removed for
1131 * zeroing, so do not issue a wakeup.
1136 vm_page_free_fromq_fast(void)
1143 lwkt_gettoken(&vm_token);
1144 for (i = 0; i < PQ_L2_SIZE; ++i) {
1145 m = vm_page_list_find(PQ_FREE, qi, FALSE);
1146 qi = (qi + PQ_PRIME2) & PQ_L2_MASK;
1147 if (m && (m->flags & PG_ZERO) == 0) {
1148 vm_page_unqueue_nowakeup(m);
1154 lwkt_reltoken(&vm_token);
1160 * vm_page_unmanage()
1162 * Prevent PV management from being done on the page. The page is
1163 * removed from the paging queues as if it were wired, and as a
1164 * consequence of no longer being managed the pageout daemon will not
1165 * touch it (since there is no way to locate the pte mappings for the
1166 * page). madvise() calls that mess with the pmap will also no longer
1167 * operate on the page.
1169 * Beyond that the page is still reasonably 'normal'. Freeing the page
1170 * will clear the flag.
1172 * This routine is used by OBJT_PHYS objects - objects using unswappable
1173 * physical memory as backing store rather then swap-backed memory and
1174 * will eventually be extended to support 4MB unmanaged physical
1177 * Must be called with a critical section held.
1178 * Must be called with vm_token held.
1181 vm_page_unmanage(vm_page_t m)
1183 ASSERT_IN_CRIT_SECTION();
1184 ASSERT_LWKT_TOKEN_HELD(&vm_token);
1185 if ((m->flags & PG_UNMANAGED) == 0) {
1186 if (m->wire_count == 0)
1189 vm_page_flag_set(m, PG_UNMANAGED);
1193 * Mark this page as wired down by yet another map, removing it from
1194 * paging queues as necessary.
1196 * The page queues must be locked.
1197 * This routine may not block.
1200 vm_page_wire(vm_page_t m)
1203 * Only bump the wire statistics if the page is not already wired,
1204 * and only unqueue the page if it is on some queue (if it is unmanaged
1205 * it is already off the queues). Don't do anything with fictitious
1206 * pages because they are always wired.
1209 lwkt_gettoken(&vm_token);
1210 if ((m->flags & PG_FICTITIOUS) == 0) {
1211 if (m->wire_count == 0) {
1212 if ((m->flags & PG_UNMANAGED) == 0)
1214 vmstats.v_wire_count++;
1217 KASSERT(m->wire_count != 0,
1218 ("vm_page_wire: wire_count overflow m=%p", m));
1220 lwkt_reltoken(&vm_token);
1225 * Release one wiring of this page, potentially enabling it to be paged again.
1227 * Many pages placed on the inactive queue should actually go
1228 * into the cache, but it is difficult to figure out which. What
1229 * we do instead, if the inactive target is well met, is to put
1230 * clean pages at the head of the inactive queue instead of the tail.
1231 * This will cause them to be moved to the cache more quickly and
1232 * if not actively re-referenced, freed more quickly. If we just
1233 * stick these pages at the end of the inactive queue, heavy filesystem
1234 * meta-data accesses can cause an unnecessary paging load on memory bound
1235 * processes. This optimization causes one-time-use metadata to be
1236 * reused more quickly.
1238 * BUT, if we are in a low-memory situation we have no choice but to
1239 * put clean pages on the cache queue.
1241 * A number of routines use vm_page_unwire() to guarantee that the page
1242 * will go into either the inactive or active queues, and will NEVER
1243 * be placed in the cache - for example, just after dirtying a page.
1244 * dirty pages in the cache are not allowed.
1246 * The page queues must be locked.
1247 * This routine may not block.
1250 vm_page_unwire(vm_page_t m, int activate)
1253 lwkt_gettoken(&vm_token);
1254 if (m->flags & PG_FICTITIOUS) {
1256 } else if (m->wire_count <= 0) {
1257 panic("vm_page_unwire: invalid wire count: %d", m->wire_count);
1259 if (--m->wire_count == 0) {
1260 --vmstats.v_wire_count;
1261 if (m->flags & PG_UNMANAGED) {
1263 } else if (activate) {
1265 &vm_page_queues[PQ_ACTIVE].pl, m, pageq);
1266 m->queue = PQ_ACTIVE;
1267 vm_page_queues[PQ_ACTIVE].lcnt++;
1268 vmstats.v_active_count++;
1270 vm_page_flag_clear(m, PG_WINATCFLS);
1272 &vm_page_queues[PQ_INACTIVE].pl, m, pageq);
1273 m->queue = PQ_INACTIVE;
1274 vm_page_queues[PQ_INACTIVE].lcnt++;
1275 vmstats.v_inactive_count++;
1276 ++vm_swapcache_inactive_heuristic;
1280 lwkt_reltoken(&vm_token);
1286 * Move the specified page to the inactive queue. If the page has
1287 * any associated swap, the swap is deallocated.
1289 * Normally athead is 0 resulting in LRU operation. athead is set
1290 * to 1 if we want this page to be 'as if it were placed in the cache',
1291 * except without unmapping it from the process address space.
1293 * This routine may not block.
1294 * The caller must hold vm_token.
1296 static __inline void
1297 _vm_page_deactivate(vm_page_t m, int athead)
1300 * Ignore if already inactive.
1302 if (m->queue == PQ_INACTIVE)
1305 if (m->wire_count == 0 && (m->flags & PG_UNMANAGED) == 0) {
1306 if ((m->queue - m->pc) == PQ_CACHE)
1307 mycpu->gd_cnt.v_reactivated++;
1308 vm_page_flag_clear(m, PG_WINATCFLS);
1311 TAILQ_INSERT_HEAD(&vm_page_queues[PQ_INACTIVE].pl,
1314 TAILQ_INSERT_TAIL(&vm_page_queues[PQ_INACTIVE].pl,
1316 ++vm_swapcache_inactive_heuristic;
1318 m->queue = PQ_INACTIVE;
1319 vm_page_queues[PQ_INACTIVE].lcnt++;
1320 vmstats.v_inactive_count++;
1325 * Attempt to deactivate a page.
1330 vm_page_deactivate(vm_page_t m)
1333 lwkt_gettoken(&vm_token);
1334 _vm_page_deactivate(m, 0);
1335 lwkt_reltoken(&vm_token);
1340 * Attempt to move a page to PQ_CACHE.
1341 * Returns 0 on failure, 1 on success
1346 vm_page_try_to_cache(vm_page_t m)
1349 lwkt_gettoken(&vm_token);
1350 if (m->dirty || m->hold_count || m->busy || m->wire_count ||
1351 (m->flags & (PG_BUSY|PG_UNMANAGED))) {
1352 lwkt_reltoken(&vm_token);
1356 vm_page_test_dirty(m);
1358 lwkt_reltoken(&vm_token);
1363 lwkt_reltoken(&vm_token);
1369 * Attempt to free the page. If we cannot free it, we do nothing.
1370 * 1 is returned on success, 0 on failure.
1375 vm_page_try_to_free(vm_page_t m)
1378 lwkt_gettoken(&vm_token);
1379 if (m->dirty || m->hold_count || m->busy || m->wire_count ||
1380 (m->flags & (PG_BUSY|PG_UNMANAGED))) {
1381 lwkt_reltoken(&vm_token);
1385 vm_page_test_dirty(m);
1387 lwkt_reltoken(&vm_token);
1392 vm_page_protect(m, VM_PROT_NONE);
1394 lwkt_reltoken(&vm_token);
1402 * Put the specified page onto the page cache queue (if appropriate).
1404 * The caller must hold vm_token.
1405 * This routine may not block.
1408 vm_page_cache(vm_page_t m)
1410 ASSERT_IN_CRIT_SECTION();
1411 ASSERT_LWKT_TOKEN_HELD(&vm_token);
1413 if ((m->flags & (PG_BUSY|PG_UNMANAGED)) || m->busy ||
1414 m->wire_count || m->hold_count) {
1415 kprintf("vm_page_cache: attempting to cache busy/held page\n");
1420 * Already in the cache (and thus not mapped)
1422 if ((m->queue - m->pc) == PQ_CACHE) {
1423 KKASSERT((m->flags & PG_MAPPED) == 0);
1428 * Caller is required to test m->dirty, but note that the act of
1429 * removing the page from its maps can cause it to become dirty
1430 * on an SMP system due to another cpu running in usermode.
1433 panic("vm_page_cache: caching a dirty page, pindex: %ld",
1438 * Remove all pmaps and indicate that the page is not
1439 * writeable or mapped. Our vm_page_protect() call may
1440 * have blocked (especially w/ VM_PROT_NONE), so recheck
1444 vm_page_protect(m, VM_PROT_NONE);
1446 if ((m->flags & (PG_BUSY|PG_UNMANAGED|PG_MAPPED)) || m->busy ||
1447 m->wire_count || m->hold_count) {
1449 } else if (m->dirty) {
1450 vm_page_deactivate(m);
1452 vm_page_unqueue_nowakeup(m);
1453 m->queue = PQ_CACHE + m->pc;
1454 vm_page_queues[m->queue].lcnt++;
1455 TAILQ_INSERT_TAIL(&vm_page_queues[m->queue].pl, m, pageq);
1456 vmstats.v_cache_count++;
1457 vm_page_free_wakeup();
1462 * vm_page_dontneed()
1464 * Cache, deactivate, or do nothing as appropriate. This routine
1465 * is typically used by madvise() MADV_DONTNEED.
1467 * Generally speaking we want to move the page into the cache so
1468 * it gets reused quickly. However, this can result in a silly syndrome
1469 * due to the page recycling too quickly. Small objects will not be
1470 * fully cached. On the otherhand, if we move the page to the inactive
1471 * queue we wind up with a problem whereby very large objects
1472 * unnecessarily blow away our inactive and cache queues.
1474 * The solution is to move the pages based on a fixed weighting. We
1475 * either leave them alone, deactivate them, or move them to the cache,
1476 * where moving them to the cache has the highest weighting.
1477 * By forcing some pages into other queues we eventually force the
1478 * system to balance the queues, potentially recovering other unrelated
1479 * space from active. The idea is to not force this to happen too
1485 vm_page_dontneed(vm_page_t m)
1487 static int dnweight;
1494 * occassionally leave the page alone
1497 lwkt_gettoken(&vm_token);
1498 if ((dnw & 0x01F0) == 0 ||
1499 m->queue == PQ_INACTIVE ||
1500 m->queue - m->pc == PQ_CACHE
1502 if (m->act_count >= ACT_INIT)
1504 lwkt_reltoken(&vm_token);
1510 vm_page_test_dirty(m);
1512 if (m->dirty || (dnw & 0x0070) == 0) {
1514 * Deactivate the page 3 times out of 32.
1519 * Cache the page 28 times out of every 32. Note that
1520 * the page is deactivated instead of cached, but placed
1521 * at the head of the queue instead of the tail.
1525 _vm_page_deactivate(m, head);
1526 lwkt_reltoken(&vm_token);
1531 * Grab a page, blocking if it is busy and allocating a page if necessary.
1532 * A busy page is returned or NULL.
1534 * If VM_ALLOC_RETRY is specified VM_ALLOC_NORMAL must also be specified.
1535 * If VM_ALLOC_RETRY is not specified
1537 * This routine may block, but if VM_ALLOC_RETRY is not set then NULL is
1538 * always returned if we had blocked.
1539 * This routine will never return NULL if VM_ALLOC_RETRY is set.
1540 * This routine may not be called from an interrupt.
1541 * The returned page may not be entirely valid.
1543 * This routine may be called from mainline code without spl protection and
1544 * be guarenteed a busied page associated with the object at the specified
1550 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags)
1555 KKASSERT(allocflags &
1556 (VM_ALLOC_NORMAL|VM_ALLOC_INTERRUPT|VM_ALLOC_SYSTEM));
1558 lwkt_gettoken(&vm_token);
1560 if ((m = vm_page_lookup(object, pindex)) != NULL) {
1561 if (m->busy || (m->flags & PG_BUSY)) {
1562 generation = object->generation;
1564 while ((object->generation == generation) &&
1565 (m->busy || (m->flags & PG_BUSY))) {
1566 vm_page_flag_set(m, PG_WANTED | PG_REFERENCED);
1567 tsleep(m, 0, "pgrbwt", 0);
1568 if ((allocflags & VM_ALLOC_RETRY) == 0) {
1579 m = vm_page_alloc(object, pindex, allocflags & ~VM_ALLOC_RETRY);
1582 if ((allocflags & VM_ALLOC_RETRY) == 0)
1587 lwkt_reltoken(&vm_token);
1593 * Mapping function for valid bits or for dirty bits in
1594 * a page. May not block.
1596 * Inputs are required to range within a page.
1602 vm_page_bits(int base, int size)
1608 base + size <= PAGE_SIZE,
1609 ("vm_page_bits: illegal base/size %d/%d", base, size)
1612 if (size == 0) /* handle degenerate case */
1615 first_bit = base >> DEV_BSHIFT;
1616 last_bit = (base + size - 1) >> DEV_BSHIFT;
1618 return ((2 << last_bit) - (1 << first_bit));
1622 * Sets portions of a page valid and clean. The arguments are expected
1623 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive
1624 * of any partial chunks touched by the range. The invalid portion of
1625 * such chunks will be zero'd.
1627 * NOTE: When truncating a buffer vnode_pager_setsize() will automatically
1628 * align base to DEV_BSIZE so as not to mark clean a partially
1629 * truncated device block. Otherwise the dirty page status might be
1632 * This routine may not block.
1634 * (base + size) must be less then or equal to PAGE_SIZE.
1637 _vm_page_zero_valid(vm_page_t m, int base, int size)
1642 if (size == 0) /* handle degenerate case */
1646 * If the base is not DEV_BSIZE aligned and the valid
1647 * bit is clear, we have to zero out a portion of the
1651 if ((frag = base & ~(DEV_BSIZE - 1)) != base &&
1652 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0
1654 pmap_zero_page_area(
1662 * If the ending offset is not DEV_BSIZE aligned and the
1663 * valid bit is clear, we have to zero out a portion of
1667 endoff = base + size;
1669 if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff &&
1670 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0
1672 pmap_zero_page_area(
1675 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))
1681 * Set valid, clear dirty bits. If validating the entire
1682 * page we can safely clear the pmap modify bit. We also
1683 * use this opportunity to clear the PG_NOSYNC flag. If a process
1684 * takes a write fault on a MAP_NOSYNC memory area the flag will
1687 * We set valid bits inclusive of any overlap, but we can only
1688 * clear dirty bits for DEV_BSIZE chunks that are fully within
1691 * Page must be busied?
1692 * No other requirements.
1695 vm_page_set_valid(vm_page_t m, int base, int size)
1697 _vm_page_zero_valid(m, base, size);
1698 m->valid |= vm_page_bits(base, size);
1703 * Set valid bits and clear dirty bits.
1705 * NOTE: This function does not clear the pmap modified bit.
1706 * Also note that e.g. NFS may use a byte-granular base
1709 * Page must be busied?
1710 * No other requirements.
1713 vm_page_set_validclean(vm_page_t m, int base, int size)
1717 _vm_page_zero_valid(m, base, size);
1718 pagebits = vm_page_bits(base, size);
1719 m->valid |= pagebits;
1720 m->dirty &= ~pagebits;
1721 if (base == 0 && size == PAGE_SIZE) {
1722 /*pmap_clear_modify(m);*/
1723 vm_page_flag_clear(m, PG_NOSYNC);
1728 * Set valid & dirty. Used by buwrite()
1730 * Page must be busied?
1731 * No other requirements.
1734 vm_page_set_validdirty(vm_page_t m, int base, int size)
1738 pagebits = vm_page_bits(base, size);
1739 m->valid |= pagebits;
1740 m->dirty |= pagebits;
1742 vm_object_set_writeable_dirty(m->object);
1748 * NOTE: This function does not clear the pmap modified bit.
1749 * Also note that e.g. NFS may use a byte-granular base
1752 * Page must be busied?
1753 * No other requirements.
1756 vm_page_clear_dirty(vm_page_t m, int base, int size)
1758 m->dirty &= ~vm_page_bits(base, size);
1759 if (base == 0 && size == PAGE_SIZE) {
1760 /*pmap_clear_modify(m);*/
1761 vm_page_flag_clear(m, PG_NOSYNC);
1766 * Make the page all-dirty.
1768 * Also make sure the related object and vnode reflect the fact that the
1769 * object may now contain a dirty page.
1771 * Page must be busied?
1772 * No other requirements.
1775 vm_page_dirty(vm_page_t m)
1778 int pqtype = m->queue - m->pc;
1780 KASSERT(pqtype != PQ_CACHE && pqtype != PQ_FREE,
1781 ("vm_page_dirty: page in free/cache queue!"));
1782 if (m->dirty != VM_PAGE_BITS_ALL) {
1783 m->dirty = VM_PAGE_BITS_ALL;
1785 vm_object_set_writeable_dirty(m->object);
1790 * Invalidates DEV_BSIZE'd chunks within a page. Both the
1791 * valid and dirty bits for the effected areas are cleared.
1793 * Page must be busied?
1795 * No other requirements.
1798 vm_page_set_invalid(vm_page_t m, int base, int size)
1802 bits = vm_page_bits(base, size);
1805 m->object->generation++;
1809 * The kernel assumes that the invalid portions of a page contain
1810 * garbage, but such pages can be mapped into memory by user code.
1811 * When this occurs, we must zero out the non-valid portions of the
1812 * page so user code sees what it expects.
1814 * Pages are most often semi-valid when the end of a file is mapped
1815 * into memory and the file's size is not page aligned.
1817 * Page must be busied?
1818 * No other requirements.
1821 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid)
1827 * Scan the valid bits looking for invalid sections that
1828 * must be zerod. Invalid sub-DEV_BSIZE'd areas ( where the
1829 * valid bit may be set ) have already been zerod by
1830 * vm_page_set_validclean().
1832 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) {
1833 if (i == (PAGE_SIZE / DEV_BSIZE) ||
1834 (m->valid & (1 << i))
1837 pmap_zero_page_area(
1840 (i - b) << DEV_BSHIFT
1848 * setvalid is TRUE when we can safely set the zero'd areas
1849 * as being valid. We can do this if there are no cache consistency
1850 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS.
1853 m->valid = VM_PAGE_BITS_ALL;
1857 * Is a (partial) page valid? Note that the case where size == 0
1858 * will return FALSE in the degenerate case where the page is entirely
1859 * invalid, and TRUE otherwise.
1862 * No other requirements.
1865 vm_page_is_valid(vm_page_t m, int base, int size)
1867 int bits = vm_page_bits(base, size);
1869 if (m->valid && ((m->valid & bits) == bits))
1876 * update dirty bits from pmap/mmu. May not block.
1878 * Caller must hold vm_token if non-blocking operation desired.
1879 * No other requirements.
1882 vm_page_test_dirty(vm_page_t m)
1884 if ((m->dirty != VM_PAGE_BITS_ALL) && pmap_is_modified(m)) {
1890 * Register an action, associating it with its vm_page
1893 vm_page_register_action(vm_page_action_t action, vm_page_event_t event)
1895 struct vm_page_action_list *list;
1898 hv = (int)((intptr_t)action->m >> 8) & VMACTION_HMASK;
1899 list = &action_list[hv];
1901 lwkt_gettoken(&vm_token);
1902 vm_page_flag_set(action->m, PG_ACTIONLIST);
1903 action->event = event;
1904 LIST_INSERT_HEAD(list, action, entry);
1905 lwkt_reltoken(&vm_token);
1909 * Unregister an action, disassociating it from its related vm_page
1912 vm_page_unregister_action(vm_page_action_t action)
1914 struct vm_page_action_list *list;
1917 lwkt_gettoken(&vm_token);
1918 if (action->event != VMEVENT_NONE) {
1919 action->event = VMEVENT_NONE;
1920 LIST_REMOVE(action, entry);
1922 hv = (int)((intptr_t)action->m >> 8) & VMACTION_HMASK;
1923 list = &action_list[hv];
1924 if (LIST_EMPTY(list))
1925 vm_page_flag_clear(action->m, PG_ACTIONLIST);
1927 lwkt_reltoken(&vm_token);
1931 * Issue an event on a VM page. Corresponding action structures are
1932 * removed from the page's list and called.
1934 * If the vm_page has no more pending action events we clear its
1935 * PG_ACTIONLIST flag.
1938 vm_page_event_internal(vm_page_t m, vm_page_event_t event)
1940 struct vm_page_action_list *list;
1941 struct vm_page_action *scan;
1942 struct vm_page_action *next;
1946 hv = (int)((intptr_t)m >> 8) & VMACTION_HMASK;
1947 list = &action_list[hv];
1950 lwkt_gettoken(&vm_token);
1951 LIST_FOREACH_MUTABLE(scan, list, entry, next) {
1953 if (scan->event == event) {
1954 scan->event = VMEVENT_NONE;
1955 LIST_REMOVE(scan, entry);
1956 scan->func(m, scan);
1964 vm_page_flag_clear(m, PG_ACTIONLIST);
1965 lwkt_reltoken(&vm_token);
1969 #include "opt_ddb.h"
1971 #include <sys/kernel.h>
1973 #include <ddb/ddb.h>
1975 DB_SHOW_COMMAND(page, vm_page_print_page_info)
1977 db_printf("vmstats.v_free_count: %d\n", vmstats.v_free_count);
1978 db_printf("vmstats.v_cache_count: %d\n", vmstats.v_cache_count);
1979 db_printf("vmstats.v_inactive_count: %d\n", vmstats.v_inactive_count);
1980 db_printf("vmstats.v_active_count: %d\n", vmstats.v_active_count);
1981 db_printf("vmstats.v_wire_count: %d\n", vmstats.v_wire_count);
1982 db_printf("vmstats.v_free_reserved: %d\n", vmstats.v_free_reserved);
1983 db_printf("vmstats.v_free_min: %d\n", vmstats.v_free_min);
1984 db_printf("vmstats.v_free_target: %d\n", vmstats.v_free_target);
1985 db_printf("vmstats.v_cache_min: %d\n", vmstats.v_cache_min);
1986 db_printf("vmstats.v_inactive_target: %d\n", vmstats.v_inactive_target);
1989 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info)
1992 db_printf("PQ_FREE:");
1993 for(i=0;i<PQ_L2_SIZE;i++) {
1994 db_printf(" %d", vm_page_queues[PQ_FREE + i].lcnt);
1998 db_printf("PQ_CACHE:");
1999 for(i=0;i<PQ_L2_SIZE;i++) {
2000 db_printf(" %d", vm_page_queues[PQ_CACHE + i].lcnt);
2004 db_printf("PQ_ACTIVE: %d, PQ_INACTIVE: %d\n",
2005 vm_page_queues[PQ_ACTIVE].lcnt,
2006 vm_page_queues[PQ_INACTIVE].lcnt);