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 static void vm_page_queue_init(void);
100 static void vm_page_free_wakeup(void);
101 static vm_page_t vm_page_select_cache(vm_object_t, vm_pindex_t);
102 static vm_page_t _vm_page_list_find2(int basequeue, int index);
104 struct vpgqueues vm_page_queues[PQ_COUNT]; /* Array of tailq lists */
106 #define ASSERT_IN_CRIT_SECTION() KKASSERT(crit_test(curthread));
108 RB_GENERATE2(vm_page_rb_tree, vm_page, rb_entry, rb_vm_page_compare,
109 vm_pindex_t, pindex);
112 vm_page_queue_init(void)
116 for (i = 0; i < PQ_L2_SIZE; i++)
117 vm_page_queues[PQ_FREE+i].cnt = &vmstats.v_free_count;
118 for (i = 0; i < PQ_L2_SIZE; i++)
119 vm_page_queues[PQ_CACHE+i].cnt = &vmstats.v_cache_count;
121 vm_page_queues[PQ_INACTIVE].cnt = &vmstats.v_inactive_count;
122 vm_page_queues[PQ_ACTIVE].cnt = &vmstats.v_active_count;
123 vm_page_queues[PQ_HOLD].cnt = &vmstats.v_active_count;
124 /* PQ_NONE has no queue */
126 for (i = 0; i < PQ_COUNT; i++)
127 TAILQ_INIT(&vm_page_queues[i].pl);
131 * note: place in initialized data section? Is this necessary?
134 int vm_page_array_size = 0;
135 int vm_page_zero_count = 0;
136 vm_page_t vm_page_array = 0;
141 * Sets the page size, perhaps based upon the memory size.
142 * Must be called before any use of page-size dependent functions.
145 vm_set_page_size(void)
147 if (vmstats.v_page_size == 0)
148 vmstats.v_page_size = PAGE_SIZE;
149 if (((vmstats.v_page_size - 1) & vmstats.v_page_size) != 0)
150 panic("vm_set_page_size: page size not a power of two");
156 * Add a new page to the freelist for use by the system. New pages
157 * are added to both the head and tail of the associated free page
158 * queue in a bottom-up fashion, so both zero'd and non-zero'd page
159 * requests pull 'recent' adds (higher physical addresses) first.
161 * Must be called in a critical section.
164 vm_add_new_page(vm_paddr_t pa)
166 struct vpgqueues *vpq;
169 ++vmstats.v_page_count;
170 ++vmstats.v_free_count;
171 m = PHYS_TO_VM_PAGE(pa);
174 m->pc = (pa >> PAGE_SHIFT) & PQ_L2_MASK;
175 m->queue = m->pc + PQ_FREE;
176 KKASSERT(m->dirty == 0);
178 vpq = &vm_page_queues[m->queue];
180 TAILQ_INSERT_TAIL(&vpq->pl, m, pageq);
182 TAILQ_INSERT_HEAD(&vpq->pl, m, pageq);
183 vpq->flipflop = 1 - vpq->flipflop;
185 vm_page_queues[m->queue].lcnt++;
192 * Initializes the resident memory module.
194 * Allocates memory for the page cells, and for the object/offset-to-page
195 * hash table headers. Each page cell is initialized and placed on the
198 * starta/enda represents the range of physical memory addresses available
199 * for use (skipping memory already used by the kernel), subject to
200 * phys_avail[]. Note that phys_avail[] has already mapped out memory
201 * already in use by the kernel.
204 vm_page_startup(vm_offset_t vaddr)
208 vm_paddr_t page_range;
215 vm_paddr_t biggestone, biggestsize;
222 vaddr = round_page(vaddr);
224 for (i = 0; phys_avail[i + 1]; i += 2) {
225 phys_avail[i] = round_page64(phys_avail[i]);
226 phys_avail[i + 1] = trunc_page64(phys_avail[i + 1]);
229 for (i = 0; phys_avail[i + 1]; i += 2) {
230 vm_paddr_t size = phys_avail[i + 1] - phys_avail[i];
232 if (size > biggestsize) {
240 end = phys_avail[biggestone+1];
241 end = trunc_page(end);
244 * Initialize the queue headers for the free queue, the active queue
245 * and the inactive queue.
248 vm_page_queue_init();
250 /* VKERNELs don't support minidumps and as such don't need vm_page_dump */
251 #if !defined(_KERNEL_VIRTUAL)
253 * Allocate a bitmap to indicate that a random physical page
254 * needs to be included in a minidump.
256 * The amd64 port needs this to indicate which direct map pages
257 * need to be dumped, via calls to dump_add_page()/dump_drop_page().
259 * However, i386 still needs this workspace internally within the
260 * minidump code. In theory, they are not needed on i386, but are
261 * included should the sf_buf code decide to use them.
263 page_range = phys_avail[(nblocks - 1) * 2 + 1] / PAGE_SIZE;
264 vm_page_dump_size = round_page(roundup2(page_range, NBBY) / NBBY);
265 end -= vm_page_dump_size;
266 vm_page_dump = (void *)pmap_map(&vaddr, end, end + vm_page_dump_size,
267 VM_PROT_READ | VM_PROT_WRITE);
268 bzero((void *)vm_page_dump, vm_page_dump_size);
272 * Compute the number of pages of memory that will be available for
273 * use (taking into account the overhead of a page structure per
276 first_page = phys_avail[0] / PAGE_SIZE;
277 page_range = phys_avail[(nblocks - 1) * 2 + 1] / PAGE_SIZE - first_page;
278 npages = (total - (page_range * sizeof(struct vm_page))) / PAGE_SIZE;
281 * Initialize the mem entry structures now, and put them in the free
284 new_end = trunc_page(end - page_range * sizeof(struct vm_page));
285 mapped = pmap_map(&vaddr, new_end, end,
286 VM_PROT_READ | VM_PROT_WRITE);
287 vm_page_array = (vm_page_t)mapped;
289 #if defined(__x86_64__) && !defined(_KERNEL_VIRTUAL)
291 * since pmap_map on amd64 returns stuff out of a direct-map region,
292 * we have to manually add these pages to the minidump tracking so
293 * that they can be dumped, including the vm_page_array.
295 for (pa = new_end; pa < phys_avail[biggestone + 1]; pa += PAGE_SIZE)
300 * Clear all of the page structures
302 bzero((caddr_t) vm_page_array, page_range * sizeof(struct vm_page));
303 vm_page_array_size = page_range;
306 * Construct the free queue(s) in ascending order (by physical
307 * address) so that the first 16MB of physical memory is allocated
308 * last rather than first. On large-memory machines, this avoids
309 * the exhaustion of low physical memory before isa_dmainit has run.
311 vmstats.v_page_count = 0;
312 vmstats.v_free_count = 0;
313 for (i = 0; phys_avail[i + 1] && npages > 0; i += 2) {
318 last_pa = phys_avail[i + 1];
319 while (pa < last_pa && npages-- > 0) {
328 * Scan comparison function for Red-Black tree scans. An inclusive
329 * (start,end) is expected. Other fields are not used.
332 rb_vm_page_scancmp(struct vm_page *p, void *data)
334 struct rb_vm_page_scan_info *info = data;
336 if (p->pindex < info->start_pindex)
338 if (p->pindex > info->end_pindex)
344 rb_vm_page_compare(struct vm_page *p1, struct vm_page *p2)
346 if (p1->pindex < p2->pindex)
348 if (p1->pindex > p2->pindex)
354 * Holding a page keeps it from being reused. Other parts of the system
355 * can still disassociate the page from its current object and free it, or
356 * perform read or write I/O on it and/or otherwise manipulate the page,
357 * but if the page is held the VM system will leave the page and its data
358 * intact and not reuse the page for other purposes until the last hold
359 * reference is released. (see vm_page_wire() if you want to prevent the
360 * page from being disassociated from its object too).
362 * The caller must hold vm_token.
364 * The caller must still validate the contents of the page and, if necessary,
365 * wait for any pending I/O (e.g. vm_page_sleep_busy() loop) to complete
366 * before manipulating the page.
369 vm_page_hold(vm_page_t m)
371 ASSERT_LWKT_TOKEN_HELD(&vm_token);
376 * The opposite of vm_page_hold(). A page can be freed while being held,
377 * which places it on the PQ_HOLD queue. We must call vm_page_free_toq()
378 * in this case to actually free it once the hold count drops to 0.
380 * The caller must hold vm_token if non-blocking operation is desired,
381 * but otherwise does not need to.
384 vm_page_unhold(vm_page_t m)
386 lwkt_gettoken(&vm_token);
388 KASSERT(m->hold_count >= 0, ("vm_page_unhold: hold count < 0!!!"));
389 if (m->hold_count == 0 && m->queue == PQ_HOLD) {
393 lwkt_reltoken(&vm_token);
397 * Inserts the given vm_page into the object and object list.
399 * The pagetables are not updated but will presumably fault the page
400 * in if necessary, or if a kernel page the caller will at some point
401 * enter the page into the kernel's pmap. We are not allowed to block
402 * here so we *can't* do this anyway.
404 * This routine may not block.
405 * This routine must be called with the vm_token held.
406 * This routine must be called with a critical section held.
409 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex)
411 ASSERT_IN_CRIT_SECTION();
412 ASSERT_LWKT_TOKEN_HELD(&vm_token);
413 if (m->object != NULL)
414 panic("vm_page_insert: already inserted");
417 * Record the object/offset pair in this page
423 * Insert it into the object.
425 vm_page_rb_tree_RB_INSERT(&object->rb_memq, m);
426 object->generation++;
429 * show that the object has one more resident page.
431 object->resident_page_count++;
434 * Since we are inserting a new and possibly dirty page,
435 * update the object's OBJ_WRITEABLE and OBJ_MIGHTBEDIRTY flags.
437 if ((m->valid & m->dirty) || (m->flags & PG_WRITEABLE))
438 vm_object_set_writeable_dirty(object);
441 * Checks for a swap assignment and sets PG_SWAPPED if appropriate.
443 swap_pager_page_inserted(m);
447 * Removes the given vm_page_t from the global (object,index) hash table
448 * and from the object's memq.
450 * The underlying pmap entry (if any) is NOT removed here.
451 * This routine may not block.
453 * The page must be BUSY and will remain BUSY on return.
454 * No other requirements.
456 * NOTE: FreeBSD side effect was to unbusy the page on return. We leave
460 vm_page_remove(vm_page_t m)
465 lwkt_gettoken(&vm_token);
466 if (m->object == NULL) {
467 lwkt_reltoken(&vm_token);
472 if ((m->flags & PG_BUSY) == 0)
473 panic("vm_page_remove: page not busy");
478 * Remove the page from the object and update the object.
480 vm_page_rb_tree_RB_REMOVE(&object->rb_memq, m);
481 object->resident_page_count--;
482 object->generation++;
485 lwkt_reltoken(&vm_token);
490 * Locate and return the page at (object, pindex), or NULL if the
491 * page could not be found.
493 * The caller must hold vm_token.
496 vm_page_lookup(vm_object_t object, vm_pindex_t pindex)
501 * Search the hash table for this object/offset pair
503 ASSERT_LWKT_TOKEN_HELD(&vm_token);
505 m = vm_page_rb_tree_RB_LOOKUP(&object->rb_memq, pindex);
507 KKASSERT(m == NULL || (m->object == object && m->pindex == pindex));
514 * Move the given memory entry from its current object to the specified
515 * target object/offset.
517 * The object must be locked.
518 * This routine may not block.
520 * Note: This routine will raise itself to splvm(), the caller need not.
522 * Note: Swap associated with the page must be invalidated by the move. We
523 * have to do this for several reasons: (1) we aren't freeing the
524 * page, (2) we are dirtying the page, (3) the VM system is probably
525 * moving the page from object A to B, and will then later move
526 * the backing store from A to B and we can't have a conflict.
528 * Note: We *always* dirty the page. It is necessary both for the
529 * fact that we moved it, and because we may be invalidating
530 * swap. If the page is on the cache, we have to deactivate it
531 * or vm_page_dirty() will panic. Dirty pages are not allowed
535 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex)
538 lwkt_gettoken(&vm_token);
540 vm_page_insert(m, new_object, new_pindex);
541 if (m->queue - m->pc == PQ_CACHE)
542 vm_page_deactivate(m);
545 lwkt_reltoken(&vm_token);
550 * vm_page_unqueue() without any wakeup. This routine is used when a page
551 * is being moved between queues or otherwise is to remain BUSYied by the
554 * The caller must hold vm_token
555 * This routine may not block.
558 vm_page_unqueue_nowakeup(vm_page_t m)
560 int queue = m->queue;
561 struct vpgqueues *pq;
563 ASSERT_LWKT_TOKEN_HELD(&vm_token);
564 if (queue != PQ_NONE) {
565 pq = &vm_page_queues[queue];
567 TAILQ_REMOVE(&pq->pl, m, pageq);
574 * vm_page_unqueue() - Remove a page from its queue, wakeup the pagedemon
577 * The caller must hold vm_token
578 * This routine may not block.
581 vm_page_unqueue(vm_page_t m)
583 int queue = m->queue;
584 struct vpgqueues *pq;
586 ASSERT_LWKT_TOKEN_HELD(&vm_token);
587 if (queue != PQ_NONE) {
589 pq = &vm_page_queues[queue];
590 TAILQ_REMOVE(&pq->pl, m, pageq);
593 if ((queue - m->pc) == PQ_CACHE || (queue - m->pc) == PQ_FREE)
599 * vm_page_list_find()
601 * Find a page on the specified queue with color optimization.
603 * The page coloring optimization attempts to locate a page that does
604 * not overload other nearby pages in the object in the cpu's L1 or L2
605 * caches. We need this optimization because cpu caches tend to be
606 * physical caches, while object spaces tend to be virtual.
608 * Must be called with vm_token held.
609 * This routine may not block.
611 * Note that this routine is carefully inlined. A non-inlined version
612 * is available for outside callers but the only critical path is
613 * from within this source file.
617 _vm_page_list_find(int basequeue, int index, boolean_t prefer_zero)
622 m = TAILQ_LAST(&vm_page_queues[basequeue+index].pl, pglist);
624 m = TAILQ_FIRST(&vm_page_queues[basequeue+index].pl);
626 m = _vm_page_list_find2(basequeue, index);
631 _vm_page_list_find2(int basequeue, int index)
635 struct vpgqueues *pq;
637 pq = &vm_page_queues[basequeue];
640 * Note that for the first loop, index+i and index-i wind up at the
641 * same place. Even though this is not totally optimal, we've already
642 * blown it by missing the cache case so we do not care.
645 for(i = PQ_L2_SIZE / 2; i > 0; --i) {
646 if ((m = TAILQ_FIRST(&pq[(index + i) & PQ_L2_MASK].pl)) != NULL)
649 if ((m = TAILQ_FIRST(&pq[(index - i) & PQ_L2_MASK].pl)) != NULL)
656 * Must be called with vm_token held if the caller desired non-blocking
657 * operation and a stable result.
660 vm_page_list_find(int basequeue, int index, boolean_t prefer_zero)
662 return(_vm_page_list_find(basequeue, index, prefer_zero));
666 * Find a page on the cache queue with color optimization. As pages
667 * might be found, but not applicable, they are deactivated. This
668 * keeps us from using potentially busy cached pages.
670 * This routine may not block.
671 * Must be called with vm_token held.
674 vm_page_select_cache(vm_object_t object, vm_pindex_t pindex)
678 ASSERT_LWKT_TOKEN_HELD(&vm_token);
680 m = _vm_page_list_find(
682 (pindex + object->pg_color) & PQ_L2_MASK,
685 if (m && ((m->flags & (PG_BUSY|PG_UNMANAGED)) || m->busy ||
686 m->hold_count || m->wire_count)) {
687 vm_page_deactivate(m);
696 * Find a free or zero page, with specified preference. We attempt to
697 * inline the nominal case and fall back to _vm_page_select_free()
700 * This routine must be called with a critical section held.
701 * This routine may not block.
703 static __inline vm_page_t
704 vm_page_select_free(vm_object_t object, vm_pindex_t pindex, boolean_t prefer_zero)
708 m = _vm_page_list_find(
710 (pindex + object->pg_color) & PQ_L2_MASK,
719 * Allocate and return a memory cell associated with this VM object/offset
724 * VM_ALLOC_NORMAL allow use of cache pages, nominal free drain
725 * VM_ALLOC_QUICK like normal but cannot use cache
726 * VM_ALLOC_SYSTEM greater free drain
727 * VM_ALLOC_INTERRUPT allow free list to be completely drained
728 * VM_ALLOC_ZERO advisory request for pre-zero'd page
730 * The object must be locked.
731 * This routine may not block.
732 * The returned page will be marked PG_BUSY
734 * Additional special handling is required when called from an interrupt
735 * (VM_ALLOC_INTERRUPT). We are not allowed to mess with the page cache
739 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int page_req)
744 lwkt_gettoken(&vm_token);
746 KKASSERT(object != NULL);
747 KASSERT(!vm_page_lookup(object, pindex),
748 ("vm_page_alloc: page already allocated"));
750 (VM_ALLOC_NORMAL|VM_ALLOC_QUICK|
751 VM_ALLOC_INTERRUPT|VM_ALLOC_SYSTEM));
754 * Certain system threads (pageout daemon, buf_daemon's) are
755 * allowed to eat deeper into the free page list.
757 if (curthread->td_flags & TDF_SYSTHREAD)
758 page_req |= VM_ALLOC_SYSTEM;
761 if (vmstats.v_free_count > vmstats.v_free_reserved ||
762 ((page_req & VM_ALLOC_INTERRUPT) && vmstats.v_free_count > 0) ||
763 ((page_req & VM_ALLOC_SYSTEM) && vmstats.v_cache_count == 0 &&
764 vmstats.v_free_count > vmstats.v_interrupt_free_min)
767 * The free queue has sufficient free pages to take one out.
769 if (page_req & VM_ALLOC_ZERO)
770 m = vm_page_select_free(object, pindex, TRUE);
772 m = vm_page_select_free(object, pindex, FALSE);
773 } else if (page_req & VM_ALLOC_NORMAL) {
775 * Allocatable from the cache (non-interrupt only). On
776 * success, we must free the page and try again, thus
777 * ensuring that vmstats.v_*_free_min counters are replenished.
780 if (curthread->td_preempted) {
781 kprintf("vm_page_alloc(): warning, attempt to allocate"
782 " cache page from preempting interrupt\n");
785 m = vm_page_select_cache(object, pindex);
788 m = vm_page_select_cache(object, pindex);
791 * On success move the page into the free queue and loop.
794 KASSERT(m->dirty == 0,
795 ("Found dirty cache page %p", m));
797 vm_page_protect(m, VM_PROT_NONE);
803 * On failure return NULL
805 lwkt_reltoken(&vm_token);
807 #if defined(DIAGNOSTIC)
808 if (vmstats.v_cache_count > 0)
809 kprintf("vm_page_alloc(NORMAL): missing pages on cache queue: %d\n", vmstats.v_cache_count);
811 vm_pageout_deficit++;
816 * No pages available, wakeup the pageout daemon and give up.
818 lwkt_reltoken(&vm_token);
820 vm_pageout_deficit++;
826 * Good page found. The page has not yet been busied. We are in
827 * a critical section.
829 KASSERT(m != NULL, ("vm_page_alloc(): missing page on free queue\n"));
830 KASSERT(m->dirty == 0,
831 ("vm_page_alloc: free/cache page %p was dirty", m));
834 * Remove from free queue
836 vm_page_unqueue_nowakeup(m);
839 * Initialize structure. Only the PG_ZERO flag is inherited. Set
842 if (m->flags & PG_ZERO) {
843 vm_page_zero_count--;
844 m->flags = PG_ZERO | PG_BUSY;
855 * vm_page_insert() is safe prior to the crit_exit(). Note also that
856 * inserting a page here does not insert it into the pmap (which
857 * could cause us to block allocating memory). We cannot block
860 vm_page_insert(m, object, pindex);
863 * Don't wakeup too often - wakeup the pageout daemon when
864 * we would be nearly out of memory.
868 lwkt_reltoken(&vm_token);
872 * A PG_BUSY page is returned.
878 * Wait for sufficient free memory for nominal heavy memory use kernel
882 vm_wait_nominal(void)
884 while (vm_page_count_min(0))
889 * Test if vm_wait_nominal() would block.
892 vm_test_nominal(void)
894 if (vm_page_count_min(0))
900 * Block until free pages are available for allocation, called in various
901 * places before memory allocations.
907 lwkt_gettoken(&vm_token);
908 if (curthread == pagethread) {
909 vm_pageout_pages_needed = 1;
910 tsleep(&vm_pageout_pages_needed, 0, "VMWait", timo);
912 if (vm_pages_needed == 0) {
914 wakeup(&vm_pages_needed);
916 tsleep(&vmstats.v_free_count, 0, "vmwait", timo);
918 lwkt_reltoken(&vm_token);
923 * Block until free pages are available for allocation
925 * Called only in vm_fault so that processes page faulting can be
932 lwkt_gettoken(&vm_token);
933 if (vm_pages_needed == 0) {
935 wakeup(&vm_pages_needed);
937 tsleep(&vmstats.v_free_count, 0, "pfault", 0);
938 lwkt_reltoken(&vm_token);
943 * Put the specified page on the active list (if appropriate). Ensure
944 * that act_count is at least ACT_INIT but do not otherwise mess with it.
946 * The page queues must be locked.
947 * This routine may not block.
950 vm_page_activate(vm_page_t m)
953 lwkt_gettoken(&vm_token);
954 if (m->queue != PQ_ACTIVE) {
955 if ((m->queue - m->pc) == PQ_CACHE)
956 mycpu->gd_cnt.v_reactivated++;
960 if (m->wire_count == 0 && (m->flags & PG_UNMANAGED) == 0) {
961 m->queue = PQ_ACTIVE;
962 vm_page_queues[PQ_ACTIVE].lcnt++;
963 TAILQ_INSERT_TAIL(&vm_page_queues[PQ_ACTIVE].pl,
965 if (m->act_count < ACT_INIT)
966 m->act_count = ACT_INIT;
967 vmstats.v_active_count++;
970 if (m->act_count < ACT_INIT)
971 m->act_count = ACT_INIT;
973 lwkt_reltoken(&vm_token);
978 * Helper routine for vm_page_free_toq() and vm_page_cache(). This
979 * routine is called when a page has been added to the cache or free
982 * This routine may not block.
983 * This routine must be called at splvm()
986 vm_page_free_wakeup(void)
989 * if pageout daemon needs pages, then tell it that there are
992 if (vm_pageout_pages_needed &&
993 vmstats.v_cache_count + vmstats.v_free_count >=
994 vmstats.v_pageout_free_min
996 wakeup(&vm_pageout_pages_needed);
997 vm_pageout_pages_needed = 0;
1001 * wakeup processes that are waiting on memory if we hit a
1002 * high water mark. And wakeup scheduler process if we have
1003 * lots of memory. this process will swapin processes.
1005 if (vm_pages_needed && !vm_page_count_min(0)) {
1006 vm_pages_needed = 0;
1007 wakeup(&vmstats.v_free_count);
1014 * Returns the given page to the PQ_FREE list, disassociating it with
1017 * The vm_page must be PG_BUSY on entry. PG_BUSY will be released on
1018 * return (the page will have been freed). No particular spl is required
1021 * This routine may not block.
1024 vm_page_free_toq(vm_page_t m)
1026 struct vpgqueues *pq;
1029 lwkt_gettoken(&vm_token);
1030 mycpu->gd_cnt.v_tfree++;
1032 KKASSERT((m->flags & PG_MAPPED) == 0);
1034 if (m->busy || ((m->queue - m->pc) == PQ_FREE)) {
1036 "vm_page_free: pindex(%lu), busy(%d), PG_BUSY(%d), hold(%d)\n",
1037 (u_long)m->pindex, m->busy, (m->flags & PG_BUSY) ? 1 : 0,
1039 if ((m->queue - m->pc) == PQ_FREE)
1040 panic("vm_page_free: freeing free page");
1042 panic("vm_page_free: freeing busy page");
1046 * unqueue, then remove page. Note that we cannot destroy
1047 * the page here because we do not want to call the pager's
1048 * callback routine until after we've put the page on the
1049 * appropriate free queue.
1051 vm_page_unqueue_nowakeup(m);
1055 * No further management of fictitious pages occurs beyond object
1056 * and queue removal.
1058 if ((m->flags & PG_FICTITIOUS) != 0) {
1060 lwkt_reltoken(&vm_token);
1068 if (m->wire_count != 0) {
1069 if (m->wire_count > 1) {
1071 "vm_page_free: invalid wire count (%d), pindex: 0x%lx",
1072 m->wire_count, (long)m->pindex);
1074 panic("vm_page_free: freeing wired page");
1078 * Clear the UNMANAGED flag when freeing an unmanaged page.
1080 if (m->flags & PG_UNMANAGED) {
1081 m->flags &= ~PG_UNMANAGED;
1084 if (m->hold_count != 0) {
1085 m->flags &= ~PG_ZERO;
1088 m->queue = PQ_FREE + m->pc;
1090 pq = &vm_page_queues[m->queue];
1095 * Put zero'd pages on the end ( where we look for zero'd pages
1096 * first ) and non-zerod pages at the head.
1098 if (m->flags & PG_ZERO) {
1099 TAILQ_INSERT_TAIL(&pq->pl, m, pageq);
1100 ++vm_page_zero_count;
1102 TAILQ_INSERT_HEAD(&pq->pl, m, pageq);
1105 vm_page_free_wakeup();
1106 lwkt_reltoken(&vm_token);
1111 * vm_page_free_fromq_fast()
1113 * Remove a non-zero page from one of the free queues; the page is removed for
1114 * zeroing, so do not issue a wakeup.
1119 vm_page_free_fromq_fast(void)
1126 lwkt_gettoken(&vm_token);
1127 for (i = 0; i < PQ_L2_SIZE; ++i) {
1128 m = vm_page_list_find(PQ_FREE, qi, FALSE);
1129 qi = (qi + PQ_PRIME2) & PQ_L2_MASK;
1130 if (m && (m->flags & PG_ZERO) == 0) {
1131 vm_page_unqueue_nowakeup(m);
1137 lwkt_reltoken(&vm_token);
1143 * vm_page_unmanage()
1145 * Prevent PV management from being done on the page. The page is
1146 * removed from the paging queues as if it were wired, and as a
1147 * consequence of no longer being managed the pageout daemon will not
1148 * touch it (since there is no way to locate the pte mappings for the
1149 * page). madvise() calls that mess with the pmap will also no longer
1150 * operate on the page.
1152 * Beyond that the page is still reasonably 'normal'. Freeing the page
1153 * will clear the flag.
1155 * This routine is used by OBJT_PHYS objects - objects using unswappable
1156 * physical memory as backing store rather then swap-backed memory and
1157 * will eventually be extended to support 4MB unmanaged physical
1160 * Must be called with a critical section held.
1161 * Must be called with vm_token held.
1164 vm_page_unmanage(vm_page_t m)
1166 ASSERT_IN_CRIT_SECTION();
1167 ASSERT_LWKT_TOKEN_HELD(&vm_token);
1168 if ((m->flags & PG_UNMANAGED) == 0) {
1169 if (m->wire_count == 0)
1172 vm_page_flag_set(m, PG_UNMANAGED);
1176 * Mark this page as wired down by yet another map, removing it from
1177 * paging queues as necessary.
1179 * The page queues must be locked.
1180 * This routine may not block.
1183 vm_page_wire(vm_page_t m)
1186 * Only bump the wire statistics if the page is not already wired,
1187 * and only unqueue the page if it is on some queue (if it is unmanaged
1188 * it is already off the queues). Don't do anything with fictitious
1189 * pages because they are always wired.
1192 lwkt_gettoken(&vm_token);
1193 if ((m->flags & PG_FICTITIOUS) == 0) {
1194 if (m->wire_count == 0) {
1195 if ((m->flags & PG_UNMANAGED) == 0)
1197 vmstats.v_wire_count++;
1200 KASSERT(m->wire_count != 0,
1201 ("vm_page_wire: wire_count overflow m=%p", m));
1203 lwkt_reltoken(&vm_token);
1208 * Release one wiring of this page, potentially enabling it to be paged again.
1210 * Many pages placed on the inactive queue should actually go
1211 * into the cache, but it is difficult to figure out which. What
1212 * we do instead, if the inactive target is well met, is to put
1213 * clean pages at the head of the inactive queue instead of the tail.
1214 * This will cause them to be moved to the cache more quickly and
1215 * if not actively re-referenced, freed more quickly. If we just
1216 * stick these pages at the end of the inactive queue, heavy filesystem
1217 * meta-data accesses can cause an unnecessary paging load on memory bound
1218 * processes. This optimization causes one-time-use metadata to be
1219 * reused more quickly.
1221 * BUT, if we are in a low-memory situation we have no choice but to
1222 * put clean pages on the cache queue.
1224 * A number of routines use vm_page_unwire() to guarantee that the page
1225 * will go into either the inactive or active queues, and will NEVER
1226 * be placed in the cache - for example, just after dirtying a page.
1227 * dirty pages in the cache are not allowed.
1229 * The page queues must be locked.
1230 * This routine may not block.
1233 vm_page_unwire(vm_page_t m, int activate)
1236 lwkt_gettoken(&vm_token);
1237 if (m->flags & PG_FICTITIOUS) {
1239 } else if (m->wire_count <= 0) {
1240 panic("vm_page_unwire: invalid wire count: %d", m->wire_count);
1242 if (--m->wire_count == 0) {
1243 --vmstats.v_wire_count;
1244 if (m->flags & PG_UNMANAGED) {
1246 } else if (activate) {
1248 &vm_page_queues[PQ_ACTIVE].pl, m, pageq);
1249 m->queue = PQ_ACTIVE;
1250 vm_page_queues[PQ_ACTIVE].lcnt++;
1251 vmstats.v_active_count++;
1253 vm_page_flag_clear(m, PG_WINATCFLS);
1255 &vm_page_queues[PQ_INACTIVE].pl, m, pageq);
1256 m->queue = PQ_INACTIVE;
1257 vm_page_queues[PQ_INACTIVE].lcnt++;
1258 vmstats.v_inactive_count++;
1259 ++vm_swapcache_inactive_heuristic;
1263 lwkt_reltoken(&vm_token);
1269 * Move the specified page to the inactive queue. If the page has
1270 * any associated swap, the swap is deallocated.
1272 * Normally athead is 0 resulting in LRU operation. athead is set
1273 * to 1 if we want this page to be 'as if it were placed in the cache',
1274 * except without unmapping it from the process address space.
1276 * This routine may not block.
1277 * The caller must hold vm_token.
1279 static __inline void
1280 _vm_page_deactivate(vm_page_t m, int athead)
1283 * Ignore if already inactive.
1285 if (m->queue == PQ_INACTIVE)
1288 if (m->wire_count == 0 && (m->flags & PG_UNMANAGED) == 0) {
1289 if ((m->queue - m->pc) == PQ_CACHE)
1290 mycpu->gd_cnt.v_reactivated++;
1291 vm_page_flag_clear(m, PG_WINATCFLS);
1294 TAILQ_INSERT_HEAD(&vm_page_queues[PQ_INACTIVE].pl,
1297 TAILQ_INSERT_TAIL(&vm_page_queues[PQ_INACTIVE].pl,
1299 ++vm_swapcache_inactive_heuristic;
1301 m->queue = PQ_INACTIVE;
1302 vm_page_queues[PQ_INACTIVE].lcnt++;
1303 vmstats.v_inactive_count++;
1308 * Attempt to deactivate a page.
1313 vm_page_deactivate(vm_page_t m)
1316 lwkt_gettoken(&vm_token);
1317 _vm_page_deactivate(m, 0);
1318 lwkt_reltoken(&vm_token);
1323 * Attempt to move a page to PQ_CACHE.
1324 * Returns 0 on failure, 1 on success
1329 vm_page_try_to_cache(vm_page_t m)
1332 lwkt_gettoken(&vm_token);
1333 if (m->dirty || m->hold_count || m->busy || m->wire_count ||
1334 (m->flags & (PG_BUSY|PG_UNMANAGED))) {
1335 lwkt_reltoken(&vm_token);
1339 vm_page_test_dirty(m);
1341 lwkt_reltoken(&vm_token);
1346 lwkt_reltoken(&vm_token);
1352 * Attempt to free the page. If we cannot free it, we do nothing.
1353 * 1 is returned on success, 0 on failure.
1358 vm_page_try_to_free(vm_page_t m)
1361 lwkt_gettoken(&vm_token);
1362 if (m->dirty || m->hold_count || m->busy || m->wire_count ||
1363 (m->flags & (PG_BUSY|PG_UNMANAGED))) {
1364 lwkt_reltoken(&vm_token);
1368 vm_page_test_dirty(m);
1370 lwkt_reltoken(&vm_token);
1375 vm_page_protect(m, VM_PROT_NONE);
1377 lwkt_reltoken(&vm_token);
1385 * Put the specified page onto the page cache queue (if appropriate).
1387 * The caller must hold vm_token.
1388 * This routine may not block.
1391 vm_page_cache(vm_page_t m)
1393 ASSERT_IN_CRIT_SECTION();
1394 ASSERT_LWKT_TOKEN_HELD(&vm_token);
1396 if ((m->flags & (PG_BUSY|PG_UNMANAGED)) || m->busy ||
1397 m->wire_count || m->hold_count) {
1398 kprintf("vm_page_cache: attempting to cache busy/held page\n");
1403 * Already in the cache (and thus not mapped)
1405 if ((m->queue - m->pc) == PQ_CACHE) {
1406 KKASSERT((m->flags & PG_MAPPED) == 0);
1411 * Caller is required to test m->dirty, but note that the act of
1412 * removing the page from its maps can cause it to become dirty
1413 * on an SMP system due to another cpu running in usermode.
1416 panic("vm_page_cache: caching a dirty page, pindex: %ld",
1421 * Remove all pmaps and indicate that the page is not
1422 * writeable or mapped. Our vm_page_protect() call may
1423 * have blocked (especially w/ VM_PROT_NONE), so recheck
1427 vm_page_protect(m, VM_PROT_NONE);
1429 if ((m->flags & (PG_BUSY|PG_UNMANAGED|PG_MAPPED)) || m->busy ||
1430 m->wire_count || m->hold_count) {
1432 } else if (m->dirty) {
1433 vm_page_deactivate(m);
1435 vm_page_unqueue_nowakeup(m);
1436 m->queue = PQ_CACHE + m->pc;
1437 vm_page_queues[m->queue].lcnt++;
1438 TAILQ_INSERT_TAIL(&vm_page_queues[m->queue].pl, m, pageq);
1439 vmstats.v_cache_count++;
1440 vm_page_free_wakeup();
1445 * vm_page_dontneed()
1447 * Cache, deactivate, or do nothing as appropriate. This routine
1448 * is typically used by madvise() MADV_DONTNEED.
1450 * Generally speaking we want to move the page into the cache so
1451 * it gets reused quickly. However, this can result in a silly syndrome
1452 * due to the page recycling too quickly. Small objects will not be
1453 * fully cached. On the otherhand, if we move the page to the inactive
1454 * queue we wind up with a problem whereby very large objects
1455 * unnecessarily blow away our inactive and cache queues.
1457 * The solution is to move the pages based on a fixed weighting. We
1458 * either leave them alone, deactivate them, or move them to the cache,
1459 * where moving them to the cache has the highest weighting.
1460 * By forcing some pages into other queues we eventually force the
1461 * system to balance the queues, potentially recovering other unrelated
1462 * space from active. The idea is to not force this to happen too
1468 vm_page_dontneed(vm_page_t m)
1470 static int dnweight;
1477 * occassionally leave the page alone
1480 lwkt_gettoken(&vm_token);
1481 if ((dnw & 0x01F0) == 0 ||
1482 m->queue == PQ_INACTIVE ||
1483 m->queue - m->pc == PQ_CACHE
1485 if (m->act_count >= ACT_INIT)
1487 lwkt_reltoken(&vm_token);
1493 vm_page_test_dirty(m);
1495 if (m->dirty || (dnw & 0x0070) == 0) {
1497 * Deactivate the page 3 times out of 32.
1502 * Cache the page 28 times out of every 32. Note that
1503 * the page is deactivated instead of cached, but placed
1504 * at the head of the queue instead of the tail.
1508 _vm_page_deactivate(m, head);
1509 lwkt_reltoken(&vm_token);
1514 * Grab a page, blocking if it is busy and allocating a page if necessary.
1515 * A busy page is returned or NULL.
1517 * If VM_ALLOC_RETRY is specified VM_ALLOC_NORMAL must also be specified.
1518 * If VM_ALLOC_RETRY is not specified
1520 * This routine may block, but if VM_ALLOC_RETRY is not set then NULL is
1521 * always returned if we had blocked.
1522 * This routine will never return NULL if VM_ALLOC_RETRY is set.
1523 * This routine may not be called from an interrupt.
1524 * The returned page may not be entirely valid.
1526 * This routine may be called from mainline code without spl protection and
1527 * be guarenteed a busied page associated with the object at the specified
1533 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags)
1538 KKASSERT(allocflags &
1539 (VM_ALLOC_NORMAL|VM_ALLOC_INTERRUPT|VM_ALLOC_SYSTEM));
1541 lwkt_gettoken(&vm_token);
1543 if ((m = vm_page_lookup(object, pindex)) != NULL) {
1544 if (m->busy || (m->flags & PG_BUSY)) {
1545 generation = object->generation;
1547 while ((object->generation == generation) &&
1548 (m->busy || (m->flags & PG_BUSY))) {
1549 vm_page_flag_set(m, PG_WANTED | PG_REFERENCED);
1550 tsleep(m, 0, "pgrbwt", 0);
1551 if ((allocflags & VM_ALLOC_RETRY) == 0) {
1562 m = vm_page_alloc(object, pindex, allocflags & ~VM_ALLOC_RETRY);
1565 if ((allocflags & VM_ALLOC_RETRY) == 0)
1570 lwkt_reltoken(&vm_token);
1576 * Mapping function for valid bits or for dirty bits in
1577 * a page. May not block.
1579 * Inputs are required to range within a page.
1585 vm_page_bits(int base, int size)
1591 base + size <= PAGE_SIZE,
1592 ("vm_page_bits: illegal base/size %d/%d", base, size)
1595 if (size == 0) /* handle degenerate case */
1598 first_bit = base >> DEV_BSHIFT;
1599 last_bit = (base + size - 1) >> DEV_BSHIFT;
1601 return ((2 << last_bit) - (1 << first_bit));
1605 * Sets portions of a page valid and clean. The arguments are expected
1606 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive
1607 * of any partial chunks touched by the range. The invalid portion of
1608 * such chunks will be zero'd.
1610 * NOTE: When truncating a buffer vnode_pager_setsize() will automatically
1611 * align base to DEV_BSIZE so as not to mark clean a partially
1612 * truncated device block. Otherwise the dirty page status might be
1615 * This routine may not block.
1617 * (base + size) must be less then or equal to PAGE_SIZE.
1620 _vm_page_zero_valid(vm_page_t m, int base, int size)
1625 if (size == 0) /* handle degenerate case */
1629 * If the base is not DEV_BSIZE aligned and the valid
1630 * bit is clear, we have to zero out a portion of the
1634 if ((frag = base & ~(DEV_BSIZE - 1)) != base &&
1635 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0
1637 pmap_zero_page_area(
1645 * If the ending offset is not DEV_BSIZE aligned and the
1646 * valid bit is clear, we have to zero out a portion of
1650 endoff = base + size;
1652 if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff &&
1653 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0
1655 pmap_zero_page_area(
1658 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))
1664 * Set valid, clear dirty bits. If validating the entire
1665 * page we can safely clear the pmap modify bit. We also
1666 * use this opportunity to clear the PG_NOSYNC flag. If a process
1667 * takes a write fault on a MAP_NOSYNC memory area the flag will
1670 * We set valid bits inclusive of any overlap, but we can only
1671 * clear dirty bits for DEV_BSIZE chunks that are fully within
1674 * Page must be busied?
1675 * No other requirements.
1678 vm_page_set_valid(vm_page_t m, int base, int size)
1680 _vm_page_zero_valid(m, base, size);
1681 m->valid |= vm_page_bits(base, size);
1686 * Set valid bits and clear dirty bits.
1688 * NOTE: This function does not clear the pmap modified bit.
1689 * Also note that e.g. NFS may use a byte-granular base
1692 * Page must be busied?
1693 * No other requirements.
1696 vm_page_set_validclean(vm_page_t m, int base, int size)
1700 _vm_page_zero_valid(m, base, size);
1701 pagebits = vm_page_bits(base, size);
1702 m->valid |= pagebits;
1703 m->dirty &= ~pagebits;
1704 if (base == 0 && size == PAGE_SIZE) {
1705 /*pmap_clear_modify(m);*/
1706 vm_page_flag_clear(m, PG_NOSYNC);
1711 * Set valid & dirty. Used by buwrite()
1713 * Page must be busied?
1714 * No other requirements.
1717 vm_page_set_validdirty(vm_page_t m, int base, int size)
1721 pagebits = vm_page_bits(base, size);
1722 m->valid |= pagebits;
1723 m->dirty |= pagebits;
1725 vm_object_set_writeable_dirty(m->object);
1731 * NOTE: This function does not clear the pmap modified bit.
1732 * Also note that e.g. NFS may use a byte-granular base
1735 * Page must be busied?
1736 * No other requirements.
1739 vm_page_clear_dirty(vm_page_t m, int base, int size)
1741 m->dirty &= ~vm_page_bits(base, size);
1742 if (base == 0 && size == PAGE_SIZE) {
1743 /*pmap_clear_modify(m);*/
1744 vm_page_flag_clear(m, PG_NOSYNC);
1749 * Make the page all-dirty.
1751 * Also make sure the related object and vnode reflect the fact that the
1752 * object may now contain a dirty page.
1754 * Page must be busied?
1755 * No other requirements.
1758 vm_page_dirty(vm_page_t m)
1761 int pqtype = m->queue - m->pc;
1763 KASSERT(pqtype != PQ_CACHE && pqtype != PQ_FREE,
1764 ("vm_page_dirty: page in free/cache queue!"));
1765 if (m->dirty != VM_PAGE_BITS_ALL) {
1766 m->dirty = VM_PAGE_BITS_ALL;
1768 vm_object_set_writeable_dirty(m->object);
1773 * Invalidates DEV_BSIZE'd chunks within a page. Both the
1774 * valid and dirty bits for the effected areas are cleared.
1776 * Page must be busied?
1778 * No other requirements.
1781 vm_page_set_invalid(vm_page_t m, int base, int size)
1785 bits = vm_page_bits(base, size);
1788 m->object->generation++;
1792 * The kernel assumes that the invalid portions of a page contain
1793 * garbage, but such pages can be mapped into memory by user code.
1794 * When this occurs, we must zero out the non-valid portions of the
1795 * page so user code sees what it expects.
1797 * Pages are most often semi-valid when the end of a file is mapped
1798 * into memory and the file's size is not page aligned.
1800 * Page must be busied?
1801 * No other requirements.
1804 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid)
1810 * Scan the valid bits looking for invalid sections that
1811 * must be zerod. Invalid sub-DEV_BSIZE'd areas ( where the
1812 * valid bit may be set ) have already been zerod by
1813 * vm_page_set_validclean().
1815 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) {
1816 if (i == (PAGE_SIZE / DEV_BSIZE) ||
1817 (m->valid & (1 << i))
1820 pmap_zero_page_area(
1823 (i - b) << DEV_BSHIFT
1831 * setvalid is TRUE when we can safely set the zero'd areas
1832 * as being valid. We can do this if there are no cache consistency
1833 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS.
1836 m->valid = VM_PAGE_BITS_ALL;
1840 * Is a (partial) page valid? Note that the case where size == 0
1841 * will return FALSE in the degenerate case where the page is entirely
1842 * invalid, and TRUE otherwise.
1845 * No other requirements.
1848 vm_page_is_valid(vm_page_t m, int base, int size)
1850 int bits = vm_page_bits(base, size);
1852 if (m->valid && ((m->valid & bits) == bits))
1859 * update dirty bits from pmap/mmu. May not block.
1861 * Caller must hold vm_token if non-blocking operation desired.
1862 * No other requirements.
1865 vm_page_test_dirty(vm_page_t m)
1867 if ((m->dirty != VM_PAGE_BITS_ALL) && pmap_is_modified(m)) {
1873 * Issue an event on a VM page. Corresponding action structures are
1874 * removed from the page's list and called.
1877 vm_page_event_internal(vm_page_t m, vm_page_event_t event)
1879 struct vm_page_action *scan, *next;
1881 LIST_FOREACH_MUTABLE(scan, &m->action_list, entry, next) {
1882 if (scan->event == event) {
1883 scan->event = VMEVENT_NONE;
1884 LIST_REMOVE(scan, entry);
1885 scan->func(m, scan);
1891 #include "opt_ddb.h"
1893 #include <sys/kernel.h>
1895 #include <ddb/ddb.h>
1897 DB_SHOW_COMMAND(page, vm_page_print_page_info)
1899 db_printf("vmstats.v_free_count: %d\n", vmstats.v_free_count);
1900 db_printf("vmstats.v_cache_count: %d\n", vmstats.v_cache_count);
1901 db_printf("vmstats.v_inactive_count: %d\n", vmstats.v_inactive_count);
1902 db_printf("vmstats.v_active_count: %d\n", vmstats.v_active_count);
1903 db_printf("vmstats.v_wire_count: %d\n", vmstats.v_wire_count);
1904 db_printf("vmstats.v_free_reserved: %d\n", vmstats.v_free_reserved);
1905 db_printf("vmstats.v_free_min: %d\n", vmstats.v_free_min);
1906 db_printf("vmstats.v_free_target: %d\n", vmstats.v_free_target);
1907 db_printf("vmstats.v_cache_min: %d\n", vmstats.v_cache_min);
1908 db_printf("vmstats.v_inactive_target: %d\n", vmstats.v_inactive_target);
1911 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info)
1914 db_printf("PQ_FREE:");
1915 for(i=0;i<PQ_L2_SIZE;i++) {
1916 db_printf(" %d", vm_page_queues[PQ_FREE + i].lcnt);
1920 db_printf("PQ_CACHE:");
1921 for(i=0;i<PQ_L2_SIZE;i++) {
1922 db_printf(" %d", vm_page_queues[PQ_CACHE + i].lcnt);
1926 db_printf("PQ_ACTIVE: %d, PQ_INACTIVE: %d\n",
1927 vm_page_queues[PQ_ACTIVE].lcnt,
1928 vm_page_queues[PQ_INACTIVE].lcnt);