2 * Copyright (c) 2003-2019 The DragonFly Project. All rights reserved.
3 * Copyright (c) 1991 Regents of the University of California.
6 * This code is derived from software contributed to Berkeley by
7 * The Mach Operating System project at Carnegie-Mellon University.
9 * This code is derived from software contributed to The DragonFly Project
10 * by Matthew Dillon <dillon@backplane.com>
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * from: @(#)vm_page.c 7.4 (Berkeley) 5/7/91
37 * $FreeBSD: src/sys/vm/vm_page.c,v 1.147.2.18 2002/03/10 05:03:19 alc Exp $
41 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
42 * All rights reserved.
44 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
46 * Permission to use, copy, modify and distribute this software and
47 * its documentation is hereby granted, provided that both the copyright
48 * notice and this permission notice appear in all copies of the
49 * software, derivative works or modified versions, and any portions
50 * thereof, and that both notices appear in supporting documentation.
52 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
53 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
54 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
56 * Carnegie Mellon requests users of this software to return to
58 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
59 * School of Computer Science
60 * Carnegie Mellon University
61 * Pittsburgh PA 15213-3890
63 * any improvements or extensions that they make and grant Carnegie the
64 * rights to redistribute these changes.
67 * Resident memory management module. The module manipulates 'VM pages'.
68 * A VM page is the core building block for memory management.
71 #include <sys/param.h>
72 #include <sys/systm.h>
73 #include <sys/malloc.h>
75 #include <sys/vmmeter.h>
76 #include <sys/vnode.h>
77 #include <sys/kernel.h>
78 #include <sys/alist.h>
79 #include <sys/sysctl.h>
80 #include <sys/cpu_topology.h>
83 #include <vm/vm_param.h>
85 #include <vm/vm_kern.h>
87 #include <vm/vm_map.h>
88 #include <vm/vm_object.h>
89 #include <vm/vm_page.h>
90 #include <vm/vm_pageout.h>
91 #include <vm/vm_pager.h>
92 #include <vm/vm_extern.h>
93 #include <vm/swap_pager.h>
95 #include <machine/inttypes.h>
96 #include <machine/md_var.h>
97 #include <machine/specialreg.h>
98 #include <machine/bus_dma.h>
100 #include <vm/vm_page2.h>
101 #include <sys/spinlock2.h>
104 * SET - Minimum required set associative size, must be a power of 2. We
105 * want this to match or exceed the set-associativeness of the cpu.
107 * GRP - A larger set that allows bleed-over into the domains of other
108 * nearby cpus. Also must be a power of 2. Used by the page zeroing
109 * code to smooth things out a bit.
111 #define PQ_SET_ASSOC 16
112 #define PQ_SET_ASSOC_MASK (PQ_SET_ASSOC - 1)
114 #define PQ_GRP_ASSOC (PQ_SET_ASSOC * 2)
115 #define PQ_GRP_ASSOC_MASK (PQ_GRP_ASSOC - 1)
117 static void vm_page_queue_init(void);
118 static void vm_page_free_wakeup(void);
119 static vm_page_t vm_page_select_cache(u_short pg_color);
120 static vm_page_t _vm_page_list_find2(int basequeue, int index);
121 static void _vm_page_deactivate_locked(vm_page_t m, int athead);
122 static void vm_numa_add_topology_mem(cpu_node_t *cpup, int physid, long bytes);
125 * Array of tailq lists
127 struct vpgqueues vm_page_queues[PQ_COUNT];
129 static volatile int vm_pages_waiting;
130 static struct alist vm_contig_alist;
131 static struct almeta vm_contig_ameta[ALIST_RECORDS_65536];
132 static struct spinlock vm_contig_spin = SPINLOCK_INITIALIZER(&vm_contig_spin, "vm_contig_spin");
134 static struct vm_page **vm_page_hash;
136 static u_long vm_dma_reserved = 0;
137 TUNABLE_ULONG("vm.dma_reserved", &vm_dma_reserved);
138 SYSCTL_ULONG(_vm, OID_AUTO, dma_reserved, CTLFLAG_RD, &vm_dma_reserved, 0,
139 "Memory reserved for DMA");
140 SYSCTL_UINT(_vm, OID_AUTO, dma_free_pages, CTLFLAG_RD,
141 &vm_contig_alist.bl_free, 0, "Memory reserved for DMA");
143 static int vm_contig_verbose = 0;
144 TUNABLE_INT("vm.contig_verbose", &vm_contig_verbose);
146 RB_GENERATE2(vm_page_rb_tree, vm_page, rb_entry, rb_vm_page_compare,
147 vm_pindex_t, pindex);
150 vm_page_queue_init(void)
154 for (i = 0; i < PQ_L2_SIZE; i++)
155 vm_page_queues[PQ_FREE+i].cnt_offset =
156 offsetof(struct vmstats, v_free_count);
157 for (i = 0; i < PQ_L2_SIZE; i++)
158 vm_page_queues[PQ_CACHE+i].cnt_offset =
159 offsetof(struct vmstats, v_cache_count);
160 for (i = 0; i < PQ_L2_SIZE; i++)
161 vm_page_queues[PQ_INACTIVE+i].cnt_offset =
162 offsetof(struct vmstats, v_inactive_count);
163 for (i = 0; i < PQ_L2_SIZE; i++)
164 vm_page_queues[PQ_ACTIVE+i].cnt_offset =
165 offsetof(struct vmstats, v_active_count);
166 for (i = 0; i < PQ_L2_SIZE; i++)
167 vm_page_queues[PQ_HOLD+i].cnt_offset =
168 offsetof(struct vmstats, v_active_count);
169 /* PQ_NONE has no queue */
171 for (i = 0; i < PQ_COUNT; i++) {
172 TAILQ_INIT(&vm_page_queues[i].pl);
173 spin_init(&vm_page_queues[i].spin, "vm_page_queue_init");
178 * note: place in initialized data section? Is this necessary?
180 vm_pindex_t first_page = 0;
181 vm_pindex_t vm_page_array_size = 0;
182 vm_page_t vm_page_array = NULL;
183 vm_paddr_t vm_low_phys_reserved;
188 * Sets the page size, perhaps based upon the memory size.
189 * Must be called before any use of page-size dependent functions.
192 vm_set_page_size(void)
194 if (vmstats.v_page_size == 0)
195 vmstats.v_page_size = PAGE_SIZE;
196 if (((vmstats.v_page_size - 1) & vmstats.v_page_size) != 0)
197 panic("vm_set_page_size: page size not a power of two");
203 * Add a new page to the freelist for use by the system. New pages
204 * are added to both the head and tail of the associated free page
205 * queue in a bottom-up fashion, so both zero'd and non-zero'd page
206 * requests pull 'recent' adds (higher physical addresses) first.
208 * Beware that the page zeroing daemon will also be running soon after
209 * boot, moving pages from the head to the tail of the PQ_FREE queues.
211 * Must be called in a critical section.
214 vm_add_new_page(vm_paddr_t pa)
216 struct vpgqueues *vpq;
219 m = PHYS_TO_VM_PAGE(pa);
222 m->pat_mode = PAT_WRITE_BACK;
223 m->pc = (pa >> PAGE_SHIFT);
226 * Twist for cpu localization in addition to page coloring, so
227 * different cpus selecting by m->queue get different page colors.
229 m->pc ^= ((pa >> PAGE_SHIFT) / PQ_L2_SIZE);
230 m->pc ^= ((pa >> PAGE_SHIFT) / (PQ_L2_SIZE * PQ_L2_SIZE));
234 * Reserve a certain number of contiguous low memory pages for
235 * contigmalloc() to use.
237 if (pa < vm_low_phys_reserved) {
238 atomic_add_long(&vmstats.v_page_count, 1);
239 atomic_add_long(&vmstats.v_dma_pages, 1);
242 atomic_add_long(&vmstats.v_wire_count, 1);
243 alist_free(&vm_contig_alist, pa >> PAGE_SHIFT, 1);
250 m->queue = m->pc + PQ_FREE;
251 KKASSERT(m->dirty == 0);
253 atomic_add_long(&vmstats.v_page_count, 1);
254 atomic_add_long(&vmstats.v_free_count, 1);
255 vpq = &vm_page_queues[m->queue];
256 TAILQ_INSERT_HEAD(&vpq->pl, m, pageq);
263 * Initializes the resident memory module.
265 * Preallocates memory for critical VM structures and arrays prior to
266 * kernel_map becoming available.
268 * Memory is allocated from (virtual2_start, virtual2_end) if available,
269 * otherwise memory is allocated from (virtual_start, virtual_end).
271 * On x86-64 (virtual_start, virtual_end) is only 2GB and may not be
272 * large enough to hold vm_page_array & other structures for machines with
273 * large amounts of ram, so we want to use virtual2* when available.
276 vm_page_startup(void)
278 vm_offset_t vaddr = virtual2_start ? virtual2_start : virtual_start;
281 vm_paddr_t page_range;
287 vm_paddr_t biggestone, biggestsize;
294 vaddr = round_page(vaddr);
297 * Make sure ranges are page-aligned.
299 for (i = 0; phys_avail[i].phys_end; ++i) {
300 phys_avail[i].phys_beg = round_page64(phys_avail[i].phys_beg);
301 phys_avail[i].phys_end = trunc_page64(phys_avail[i].phys_end);
302 if (phys_avail[i].phys_end < phys_avail[i].phys_beg)
303 phys_avail[i].phys_end = phys_avail[i].phys_beg;
307 * Locate largest block
309 for (i = 0; phys_avail[i].phys_end; ++i) {
310 vm_paddr_t size = phys_avail[i].phys_end -
311 phys_avail[i].phys_beg;
313 if (size > biggestsize) {
319 --i; /* adjust to last entry for use down below */
321 end = phys_avail[biggestone].phys_end;
322 end = trunc_page(end);
325 * Initialize the queue headers for the free queue, the active queue
326 * and the inactive queue.
328 vm_page_queue_init();
330 #if !defined(_KERNEL_VIRTUAL)
332 * VKERNELs don't support minidumps and as such don't need
335 * Allocate a bitmap to indicate that a random physical page
336 * needs to be included in a minidump.
338 * The amd64 port needs this to indicate which direct map pages
339 * need to be dumped, via calls to dump_add_page()/dump_drop_page().
341 * However, x86 still needs this workspace internally within the
342 * minidump code. In theory, they are not needed on x86, but are
343 * included should the sf_buf code decide to use them.
345 page_range = phys_avail[i].phys_end / PAGE_SIZE;
346 vm_page_dump_size = round_page(roundup2(page_range, NBBY) / NBBY);
347 end -= vm_page_dump_size;
348 vm_page_dump = (void *)pmap_map(&vaddr, end, end + vm_page_dump_size,
349 VM_PROT_READ | VM_PROT_WRITE);
350 bzero((void *)vm_page_dump, vm_page_dump_size);
353 * Compute the number of pages of memory that will be available for
354 * use (taking into account the overhead of a page structure per
357 first_page = phys_avail[0].phys_beg / PAGE_SIZE;
358 page_range = phys_avail[i].phys_end / PAGE_SIZE - first_page;
359 npages = (total - (page_range * sizeof(struct vm_page))) / PAGE_SIZE;
361 #ifndef _KERNEL_VIRTUAL
363 * (only applies to real kernels)
365 * Reserve a large amount of low memory for potential 32-bit DMA
366 * space allocations. Once device initialization is complete we
367 * release most of it, but keep (vm_dma_reserved) memory reserved
368 * for later use. Typically for X / graphics. Through trial and
369 * error we find that GPUs usually requires ~60-100MB or so.
371 * By default, 128M is left in reserve on machines with 2G+ of ram.
373 vm_low_phys_reserved = (vm_paddr_t)65536 << PAGE_SHIFT;
374 if (vm_low_phys_reserved > total / 4)
375 vm_low_phys_reserved = total / 4;
376 if (vm_dma_reserved == 0) {
377 vm_dma_reserved = 128 * 1024 * 1024; /* 128MB */
378 if (vm_dma_reserved > total / 16)
379 vm_dma_reserved = total / 16;
382 alist_init(&vm_contig_alist, 65536, vm_contig_ameta,
383 ALIST_RECORDS_65536);
386 * Initialize the mem entry structures now, and put them in the free
389 if (bootverbose && ctob(physmem) >= 400LL*1024*1024*1024)
390 kprintf("initializing vm_page_array ");
391 new_end = trunc_page(end - page_range * sizeof(struct vm_page));
392 mapped = pmap_map(&vaddr, new_end, end, VM_PROT_READ | VM_PROT_WRITE);
393 vm_page_array = (vm_page_t)mapped;
395 #if defined(__x86_64__) && !defined(_KERNEL_VIRTUAL)
397 * since pmap_map on amd64 returns stuff out of a direct-map region,
398 * we have to manually add these pages to the minidump tracking so
399 * that they can be dumped, including the vm_page_array.
402 pa < phys_avail[biggestone].phys_end;
409 * Clear all of the page structures, run basic initialization so
410 * PHYS_TO_VM_PAGE() operates properly even on pages not in the
413 bzero((caddr_t) vm_page_array, page_range * sizeof(struct vm_page));
414 vm_page_array_size = page_range;
415 if (bootverbose && ctob(physmem) >= 400LL*1024*1024*1024)
416 kprintf("size = 0x%zx\n", vm_page_array_size);
418 m = &vm_page_array[0];
419 pa = ptoa(first_page);
420 for (i = 0; i < page_range; ++i) {
421 spin_init(&m->spin, "vm_page");
428 * Construct the free queue(s) in ascending order (by physical
429 * address) so that the first 16MB of physical memory is allocated
430 * last rather than first. On large-memory machines, this avoids
431 * the exhaustion of low physical memory before isa_dma_init has run.
433 vmstats.v_page_count = 0;
434 vmstats.v_free_count = 0;
435 for (i = 0; phys_avail[i].phys_end && npages > 0; ++i) {
436 pa = phys_avail[i].phys_beg;
440 last_pa = phys_avail[i].phys_end;
441 while (pa < last_pa && npages-- > 0) {
447 virtual2_start = vaddr;
449 virtual_start = vaddr;
450 mycpu->gd_vmstats = vmstats;
454 * (called from early boot only)
456 * Reorganize VM pages based on numa data. May be called as many times as
457 * necessary. Will reorganize the vm_page_t page color and related queue(s)
458 * to allow vm_page_alloc() to choose pages based on socket affinity.
460 * NOTE: This function is only called while we are still in UP mode, so
461 * we only need a critical section to protect the queues (which
462 * saves a lot of time, there are likely a ton of pages).
465 vm_numa_organize(vm_paddr_t ran_beg, vm_paddr_t bytes, int physid)
470 struct vpgqueues *vpq;
478 * Check if no physical information, or there was only one socket
479 * (so don't waste time doing nothing!).
481 if (cpu_topology_phys_ids <= 1 ||
482 cpu_topology_core_ids == 0) {
487 * Setup for our iteration. Note that ACPI may iterate CPU
488 * sockets starting at 0 or 1 or some other number. The
489 * cpu_topology code mod's it against the socket count.
491 ran_end = ran_beg + bytes;
493 socket_mod = PQ_L2_SIZE / cpu_topology_phys_ids;
494 socket_value = (physid % cpu_topology_phys_ids) * socket_mod;
495 mend = &vm_page_array[vm_page_array_size];
500 * Adjust cpu_topology's phys_mem parameter
503 vm_numa_add_topology_mem(root_cpu_node, physid, (long)bytes);
506 * Adjust vm_page->pc and requeue all affected pages. The
507 * allocator will then be able to localize memory allocations
510 for (i = 0; phys_avail[i].phys_end; ++i) {
511 scan_beg = phys_avail[i].phys_beg;
512 scan_end = phys_avail[i].phys_end;
513 if (scan_end <= ran_beg)
515 if (scan_beg >= ran_end)
517 if (scan_beg < ran_beg)
519 if (scan_end > ran_end)
521 if (atop(scan_end) > first_page + vm_page_array_size)
522 scan_end = ptoa(first_page + vm_page_array_size);
524 m = PHYS_TO_VM_PAGE(scan_beg);
525 while (scan_beg < scan_end) {
527 if (m->queue != PQ_NONE) {
528 vpq = &vm_page_queues[m->queue];
529 TAILQ_REMOVE(&vpq->pl, m, pageq);
531 /* queue doesn't change, no need to adj cnt */
534 m->pc += socket_value;
537 vpq = &vm_page_queues[m->queue];
538 TAILQ_INSERT_HEAD(&vpq->pl, m, pageq);
540 /* queue doesn't change, no need to adj cnt */
543 m->pc += socket_value;
546 scan_beg += PAGE_SIZE;
555 * (called from early boot only)
557 * Don't allow the NUMA organization to leave vm_page_queues[] nodes
558 * completely empty for a logical cpu. Doing so would force allocations
559 * on that cpu to always borrow from a nearby cpu, create unnecessary
560 * contention, and cause vm_page_alloc() to iterate more queues and run more
563 * This situation can occur when memory sticks are not entirely populated,
564 * populated at different densities, or in naturally assymetric systems
565 * such as the 2990WX. There could very well be many vm_page_queues[]
566 * entries with *NO* pages assigned to them.
568 * Fixing this up ensures that each logical CPU has roughly the same
569 * sized memory pool, and more importantly ensures that logical CPUs
570 * do not wind up with an empty memory pool.
572 * At them moment we just iterate the other queues and borrow pages,
573 * moving them into the queues for cpus with severe deficits even though
574 * the memory might not be local to those cpus. I am not doing this in
575 * a 'smart' way, its effectively UMA style (sorta, since its page-by-page
576 * whereas real UMA typically exchanges address bits 8-10 with high address
577 * bits). But it works extremely well and gives us fairly good deterministic
578 * results on the cpu cores associated with these secondary nodes.
581 vm_numa_organize_finalize(void)
583 struct vpgqueues *vpq;
594 * Machines might not use an exact power of 2 for phys_ids,
595 * core_ids, ht_ids, etc. This can slightly reduce the actual
596 * range of indices in vm_page_queues[] that are nominally used.
598 if (cpu_topology_ht_ids) {
599 scale_lim = PQ_L2_SIZE / cpu_topology_phys_ids;
600 scale_lim = scale_lim / cpu_topology_core_ids;
601 scale_lim = scale_lim / cpu_topology_ht_ids;
602 scale_lim = scale_lim * cpu_topology_ht_ids;
603 scale_lim = scale_lim * cpu_topology_core_ids;
604 scale_lim = scale_lim * cpu_topology_phys_ids;
606 scale_lim = PQ_L2_SIZE;
610 * Calculate an average, set hysteresis for balancing from
611 * 10% below the average to the average.
614 for (i = 0; i < scale_lim; ++i) {
615 lcnt_hi += vm_page_queues[i].lcnt;
617 lcnt_hi /= scale_lim;
618 lcnt_lo = lcnt_hi - lcnt_hi / 10;
620 kprintf("vm_page: avg %ld pages per queue, %d queues\n",
624 for (i = 0; i < scale_lim; ++i) {
625 vpq = &vm_page_queues[PQ_FREE + i];
626 while (vpq->lcnt < lcnt_lo) {
627 struct vpgqueues *vptmp;
629 iter = (iter + 1) & PQ_L2_MASK;
630 vptmp = &vm_page_queues[PQ_FREE + iter];
631 if (vptmp->lcnt < lcnt_hi)
633 m = TAILQ_FIRST(&vptmp->pl);
634 KKASSERT(m->queue == PQ_FREE + iter);
635 TAILQ_REMOVE(&vptmp->pl, m, pageq);
637 /* queue doesn't change, no need to adj cnt */
641 TAILQ_INSERT_HEAD(&vpq->pl, m, pageq);
650 vm_numa_add_topology_mem(cpu_node_t *cpup, int physid, long bytes)
657 cpup->phys_mem += bytes;
661 * All members should have the same chipid, so we only need
662 * to pull out one member.
664 if (CPUMASK_TESTNZERO(cpup->members)) {
665 cpuid = BSFCPUMASK(cpup->members);
667 get_chip_ID_from_APICID(CPUID_TO_APICID(cpuid))) {
668 cpup->phys_mem += bytes;
675 * Just inherit from the parent node
677 cpup->phys_mem = cpup->parent_node->phys_mem;
680 for (i = 0; i < MAXCPU && cpup->child_node[i]; ++i)
681 vm_numa_add_topology_mem(cpup->child_node[i], physid, bytes);
685 * We tended to reserve a ton of memory for contigmalloc(). Now that most
686 * drivers have initialized we want to return most the remaining free
687 * reserve back to the VM page queues so they can be used for normal
690 * We leave vm_dma_reserved bytes worth of free pages in the reserve pool.
693 vm_page_startup_finish(void *dummy __unused)
703 spin_lock(&vm_contig_spin);
705 bfree = alist_free_info(&vm_contig_alist, &blk, &count);
706 if (bfree <= vm_dma_reserved / PAGE_SIZE)
712 * Figure out how much of the initial reserve we have to
713 * free in order to reach our target.
715 bfree -= vm_dma_reserved / PAGE_SIZE;
717 blk += count - bfree;
722 * Calculate the nearest power of 2 <= count.
724 for (xcount = 1; xcount <= count; xcount <<= 1)
727 blk += count - xcount;
731 * Allocate the pages from the alist, then free them to
732 * the normal VM page queues.
734 * Pages allocated from the alist are wired. We have to
735 * busy, unwire, and free them. We must also adjust
736 * vm_low_phys_reserved before freeing any pages to prevent
739 rblk = alist_alloc(&vm_contig_alist, blk, count);
741 kprintf("vm_page_startup_finish: Unable to return "
742 "dma space @0x%08x/%d -> 0x%08x\n",
746 atomic_add_long(&vmstats.v_dma_pages, -(long)count);
747 spin_unlock(&vm_contig_spin);
749 m = PHYS_TO_VM_PAGE((vm_paddr_t)blk << PAGE_SHIFT);
750 vm_low_phys_reserved = VM_PAGE_TO_PHYS(m);
752 vm_page_busy_wait(m, FALSE, "cpgfr");
753 vm_page_unwire(m, 0);
758 spin_lock(&vm_contig_spin);
760 spin_unlock(&vm_contig_spin);
763 * Print out how much DMA space drivers have already allocated and
764 * how much is left over.
766 kprintf("DMA space used: %jdk, remaining available: %jdk\n",
767 (intmax_t)(vmstats.v_dma_pages - vm_contig_alist.bl_free) *
769 (intmax_t)vm_contig_alist.bl_free * (PAGE_SIZE / 1024));
772 * hash table for vm_page_lookup_quick()
774 mp = (void *)kmem_alloc3(&kernel_map,
775 vm_page_array_size * sizeof(vm_page_t),
776 VM_SUBSYS_VMPGHASH, KM_CPU(0));
777 bzero(mp, vm_page_array_size * sizeof(vm_page_t));
781 SYSINIT(vm_pgend, SI_SUB_PROC0_POST, SI_ORDER_ANY,
782 vm_page_startup_finish, NULL);
786 * Scan comparison function for Red-Black tree scans. An inclusive
787 * (start,end) is expected. Other fields are not used.
790 rb_vm_page_scancmp(struct vm_page *p, void *data)
792 struct rb_vm_page_scan_info *info = data;
794 if (p->pindex < info->start_pindex)
796 if (p->pindex > info->end_pindex)
802 rb_vm_page_compare(struct vm_page *p1, struct vm_page *p2)
804 if (p1->pindex < p2->pindex)
806 if (p1->pindex > p2->pindex)
812 vm_page_init(vm_page_t m)
814 /* do nothing for now. Called from pmap_page_init() */
818 * Each page queue has its own spin lock, which is fairly optimal for
819 * allocating and freeing pages at least.
821 * The caller must hold the vm_page_spin_lock() before locking a vm_page's
822 * queue spinlock via this function. Also note that m->queue cannot change
823 * unless both the page and queue are locked.
827 _vm_page_queue_spin_lock(vm_page_t m)
832 if (queue != PQ_NONE) {
833 spin_lock(&vm_page_queues[queue].spin);
834 KKASSERT(queue == m->queue);
840 _vm_page_queue_spin_unlock(vm_page_t m)
846 if (queue != PQ_NONE)
847 spin_unlock(&vm_page_queues[queue].spin);
852 _vm_page_queues_spin_lock(u_short queue)
855 if (queue != PQ_NONE)
856 spin_lock(&vm_page_queues[queue].spin);
862 _vm_page_queues_spin_unlock(u_short queue)
865 if (queue != PQ_NONE)
866 spin_unlock(&vm_page_queues[queue].spin);
870 vm_page_queue_spin_lock(vm_page_t m)
872 _vm_page_queue_spin_lock(m);
876 vm_page_queues_spin_lock(u_short queue)
878 _vm_page_queues_spin_lock(queue);
882 vm_page_queue_spin_unlock(vm_page_t m)
884 _vm_page_queue_spin_unlock(m);
888 vm_page_queues_spin_unlock(u_short queue)
890 _vm_page_queues_spin_unlock(queue);
894 * This locks the specified vm_page and its queue in the proper order
895 * (page first, then queue). The queue may change so the caller must
900 _vm_page_and_queue_spin_lock(vm_page_t m)
902 vm_page_spin_lock(m);
903 _vm_page_queue_spin_lock(m);
908 _vm_page_and_queue_spin_unlock(vm_page_t m)
910 _vm_page_queues_spin_unlock(m->queue);
911 vm_page_spin_unlock(m);
915 vm_page_and_queue_spin_unlock(vm_page_t m)
917 _vm_page_and_queue_spin_unlock(m);
921 vm_page_and_queue_spin_lock(vm_page_t m)
923 _vm_page_and_queue_spin_lock(m);
927 * Helper function removes vm_page from its current queue.
928 * Returns the base queue the page used to be on.
930 * The vm_page and the queue must be spinlocked.
931 * This function will unlock the queue but leave the page spinlocked.
933 static __inline u_short
934 _vm_page_rem_queue_spinlocked(vm_page_t m)
936 struct vpgqueues *pq;
942 if (queue != PQ_NONE) {
943 pq = &vm_page_queues[queue];
944 TAILQ_REMOVE(&pq->pl, m, pageq);
947 * Adjust our pcpu stats. In order for the nominal low-memory
948 * algorithms to work properly we don't let any pcpu stat get
949 * too negative before we force it to be rolled-up into the
950 * global stats. Otherwise our pageout and vm_wait tests
953 * The idea here is to reduce unnecessary SMP cache
954 * mastership changes in the global vmstats, which can be
955 * particularly bad in multi-socket systems.
957 cnt = (long *)((char *)&mycpu->gd_vmstats_adj + pq->cnt_offset);
958 atomic_add_long(cnt, -1);
959 if (*cnt < -VMMETER_SLOP_COUNT) {
960 u_long copy = atomic_swap_long(cnt, 0);
961 cnt = (long *)((char *)&vmstats + pq->cnt_offset);
962 atomic_add_long(cnt, copy);
963 cnt = (long *)((char *)&mycpu->gd_vmstats +
965 atomic_add_long(cnt, copy);
971 vm_page_queues_spin_unlock(oqueue); /* intended */
977 * Helper function places the vm_page on the specified queue. Generally
978 * speaking only PQ_FREE pages are placed at the head, to allow them to
979 * be allocated sooner rather than later on the assumption that they
982 * The vm_page must be spinlocked.
983 * The vm_page must NOT be FICTITIOUS (that would be a disaster)
984 * This function will return with both the page and the queue locked.
987 _vm_page_add_queue_spinlocked(vm_page_t m, u_short queue, int athead)
989 struct vpgqueues *pq;
992 KKASSERT(m->queue == PQ_NONE && (m->flags & PG_FICTITIOUS) == 0);
994 if (queue != PQ_NONE) {
995 vm_page_queues_spin_lock(queue);
996 pq = &vm_page_queues[queue];
1000 * Adjust our pcpu stats. If a system entity really needs
1001 * to incorporate the count it will call vmstats_rollup()
1002 * to roll it all up into the global vmstats strufture.
1004 cnt = (long *)((char *)&mycpu->gd_vmstats_adj + pq->cnt_offset);
1005 atomic_add_long(cnt, 1);
1008 * PQ_FREE is always handled LIFO style to try to provide
1009 * cache-hot pages to programs.
1012 if (queue - m->pc == PQ_FREE) {
1013 TAILQ_INSERT_HEAD(&pq->pl, m, pageq);
1014 } else if (athead) {
1015 TAILQ_INSERT_HEAD(&pq->pl, m, pageq);
1017 TAILQ_INSERT_TAIL(&pq->pl, m, pageq);
1019 /* leave the queue spinlocked */
1024 * Wait until page is no longer BUSY. If also_m_busy is TRUE we wait
1025 * until the page is no longer BUSY or SBUSY (busy_count field is 0).
1027 * Returns TRUE if it had to sleep, FALSE if we did not. Only one sleep
1028 * call will be made before returning.
1030 * This function does NOT busy the page and on return the page is not
1031 * guaranteed to be available.
1034 vm_page_sleep_busy(vm_page_t m, int also_m_busy, const char *msg)
1036 u_int32_t busy_count;
1039 busy_count = m->busy_count;
1042 if ((busy_count & PBUSY_LOCKED) == 0 &&
1043 (also_m_busy == 0 || (busy_count & PBUSY_MASK) == 0)) {
1046 tsleep_interlock(m, 0);
1047 if (atomic_cmpset_int(&m->busy_count, busy_count,
1048 busy_count | PBUSY_WANTED)) {
1049 atomic_set_int(&m->flags, PG_REFERENCED);
1050 tsleep(m, PINTERLOCKED, msg, 0);
1057 * This calculates and returns a page color given an optional VM object and
1058 * either a pindex or an iterator. We attempt to return a cpu-localized
1059 * pg_color that is still roughly 16-way set-associative. The CPU topology
1060 * is used if it was probed.
1062 * The caller may use the returned value to index into e.g. PQ_FREE when
1063 * allocating a page in order to nominally obtain pages that are hopefully
1064 * already localized to the requesting cpu. This function is not able to
1065 * provide any sort of guarantee of this, but does its best to improve
1066 * hardware cache management performance.
1068 * WARNING! The caller must mask the returned value with PQ_L2_MASK.
1071 vm_get_pg_color(int cpuid, vm_object_t object, vm_pindex_t pindex)
1074 int object_pg_color;
1077 * WARNING! cpu_topology_core_ids might not be a power of two.
1078 * We also shouldn't make assumptions about
1079 * cpu_topology_phys_ids either.
1081 * WARNING! ncpus might not be known at this time (during early
1082 * boot), and might be set to 1.
1084 * General format: [phys_id][core_id][cpuid][set-associativity]
1085 * (but uses modulo, so not necessarily precise bit masks)
1087 object_pg_color = object ? object->pg_color : 0;
1089 if (cpu_topology_ht_ids) {
1098 * Translate cpuid to socket, core, and hyperthread id.
1100 phys_id = get_cpu_phys_id(cpuid);
1101 core_id = get_cpu_core_id(cpuid);
1102 ht_id = get_cpu_ht_id(cpuid);
1105 * Calculate pg_color for our array index.
1107 * physcale - socket multiplier.
1108 * grpscale - core multiplier (cores per socket)
1109 * cpu* - cpus per core
1111 * WARNING! In early boot, ncpus has not yet been
1112 * initialized and may be set to (1).
1114 * WARNING! physcale must match the organization that
1115 * vm_numa_organize() creates to ensure that
1116 * we properly localize allocations to the
1119 physcale = PQ_L2_SIZE / cpu_topology_phys_ids;
1120 grpscale = physcale / cpu_topology_core_ids;
1121 cpuscale = grpscale / cpu_topology_ht_ids;
1123 pg_color = phys_id * physcale;
1124 pg_color += core_id * grpscale;
1125 pg_color += ht_id * cpuscale;
1126 pg_color += (pindex + object_pg_color) % cpuscale;
1130 pg_color += (pindex + object_pg_color) % grpsize;
1135 /* 3->9, 4->8, 5->10, 6->12, 7->14 */
1140 pg_color += (pindex + object_pg_color) % grpsize;
1145 * Unknown topology, distribute things evenly.
1147 * WARNING! In early boot, ncpus has not yet been
1148 * initialized and may be set to (1).
1152 cpuscale = PQ_L2_SIZE / ncpus;
1154 pg_color = cpuid * cpuscale;
1155 pg_color += (pindex + object_pg_color) % cpuscale;
1157 return (pg_color & PQ_L2_MASK);
1161 * Wait until BUSY can be set, then set it. If also_m_busy is TRUE we
1162 * also wait for m->busy_count to become 0 before setting PBUSY_LOCKED.
1165 VM_PAGE_DEBUG_EXT(vm_page_busy_wait)(vm_page_t m,
1166 int also_m_busy, const char *msg
1169 u_int32_t busy_count;
1172 busy_count = m->busy_count;
1174 if (busy_count & PBUSY_LOCKED) {
1175 tsleep_interlock(m, 0);
1176 if (atomic_cmpset_int(&m->busy_count, busy_count,
1177 busy_count | PBUSY_WANTED)) {
1178 atomic_set_int(&m->flags, PG_REFERENCED);
1179 tsleep(m, PINTERLOCKED, msg, 0);
1181 } else if (also_m_busy && busy_count) {
1182 tsleep_interlock(m, 0);
1183 if (atomic_cmpset_int(&m->busy_count, busy_count,
1184 busy_count | PBUSY_WANTED)) {
1185 atomic_set_int(&m->flags, PG_REFERENCED);
1186 tsleep(m, PINTERLOCKED, msg, 0);
1189 if (atomic_cmpset_int(&m->busy_count, busy_count,
1190 busy_count | PBUSY_LOCKED)) {
1191 #ifdef VM_PAGE_DEBUG
1192 m->busy_func = func;
1193 m->busy_line = lineno;
1202 * Attempt to set BUSY. If also_m_busy is TRUE we only succeed if
1203 * m->busy_count is also 0.
1205 * Returns non-zero on failure.
1208 VM_PAGE_DEBUG_EXT(vm_page_busy_try)(vm_page_t m, int also_m_busy
1211 u_int32_t busy_count;
1214 busy_count = m->busy_count;
1216 if (busy_count & PBUSY_LOCKED)
1218 if (also_m_busy && (busy_count & PBUSY_MASK) != 0)
1220 if (atomic_cmpset_int(&m->busy_count, busy_count,
1221 busy_count | PBUSY_LOCKED)) {
1222 #ifdef VM_PAGE_DEBUG
1223 m->busy_func = func;
1224 m->busy_line = lineno;
1232 * Clear the BUSY flag and return non-zero to indicate to the caller
1233 * that a wakeup() should be performed.
1239 _vm_page_wakeup(vm_page_t m)
1241 u_int32_t busy_count;
1243 busy_count = m->busy_count;
1246 if (atomic_fcmpset_int(&m->busy_count, &busy_count,
1248 ~(PBUSY_LOCKED | PBUSY_WANTED))) {
1249 return((int)(busy_count & PBUSY_WANTED));
1256 * Clear the BUSY flag and wakeup anyone waiting for the page. This
1257 * is typically the last call you make on a page before moving onto
1261 vm_page_wakeup(vm_page_t m)
1263 KASSERT(m->busy_count & PBUSY_LOCKED,
1264 ("vm_page_wakeup: page not busy!!!"));
1265 if (_vm_page_wakeup(m))
1270 * Hold a page, preventing reuse. This is typically only called on pages
1271 * in a known state (either held busy, special, or interlocked in some
1272 * manner). Holding a page does not ensure that it remains valid, it only
1273 * prevents reuse. The page must not already be on the FREE queue or in
1274 * any danger of being moved to the FREE queue concurrent with this call.
1276 * Other parts of the system can still disassociate the page from its object
1277 * and attempt to free it, or perform read or write I/O on it and/or otherwise
1278 * manipulate the page, but if the page is held the VM system will leave the
1279 * page and its data intact and not cycle it through the FREE queue until
1280 * the last hold has been released.
1282 * (see vm_page_wire() if you want to prevent the page from being
1283 * disassociated from its object too).
1286 vm_page_hold(vm_page_t m)
1288 atomic_add_int(&m->hold_count, 1);
1289 KKASSERT(m->queue - m->pc != PQ_FREE);
1291 vm_page_spin_lock(m);
1292 atomic_add_int(&m->hold_count, 1);
1293 if (m->queue - m->pc == PQ_FREE) {
1294 _vm_page_queue_spin_lock(m);
1295 _vm_page_rem_queue_spinlocked(m);
1296 _vm_page_add_queue_spinlocked(m, PQ_HOLD + m->pc, 0);
1297 _vm_page_queue_spin_unlock(m);
1299 vm_page_spin_unlock(m);
1304 * The opposite of vm_page_hold(). If the page is on the HOLD queue
1305 * it was freed while held and must be moved back to the FREE queue.
1307 * To avoid racing against vm_page_free*() we must re-test conditions
1308 * after obtaining the spin-lock. The initial test can also race a
1309 * vm_page_free*() that is in the middle of moving a page to PQ_HOLD,
1310 * leaving the page on PQ_HOLD with hold_count == 0. Rather than
1311 * throw a spin-lock in the critical path, we rely on the pageout
1312 * daemon to clean-up these loose ends.
1314 * More critically, the 'easy movement' between queues without busying
1315 * a vm_page is only allowed for PQ_FREE<->PQ_HOLD.
1318 vm_page_unhold(vm_page_t m)
1320 KASSERT(m->hold_count > 0 && m->queue - m->pc != PQ_FREE,
1321 ("vm_page_unhold: pg %p illegal hold_count (%d) or "
1322 "on FREE queue (%d)",
1323 m, m->hold_count, m->queue - m->pc));
1325 if (atomic_fetchadd_int(&m->hold_count, -1) == 1 &&
1326 m->queue - m->pc == PQ_HOLD) {
1327 vm_page_spin_lock(m);
1328 if (m->hold_count == 0 && m->queue - m->pc == PQ_HOLD) {
1329 _vm_page_queue_spin_lock(m);
1330 _vm_page_rem_queue_spinlocked(m);
1331 _vm_page_add_queue_spinlocked(m, PQ_FREE + m->pc, 1);
1332 _vm_page_queue_spin_unlock(m);
1334 vm_page_spin_unlock(m);
1339 * Create a fictitious page with the specified physical address and
1340 * memory attribute. The memory attribute is the only the machine-
1341 * dependent aspect of a fictitious page that must be initialized.
1344 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr)
1347 if ((m->flags & PG_FICTITIOUS) != 0) {
1349 * The page's memattr might have changed since the
1350 * previous initialization. Update the pmap to the
1355 m->phys_addr = paddr;
1357 /* Fictitious pages don't use "segind". */
1358 /* Fictitious pages don't use "order" or "pool". */
1359 m->flags = PG_FICTITIOUS | PG_UNMANAGED;
1360 m->busy_count = PBUSY_LOCKED;
1362 spin_init(&m->spin, "fake_page");
1365 pmap_page_set_memattr(m, memattr);
1369 * Inserts the given vm_page into the object and object list.
1371 * The pagetables are not updated but will presumably fault the page
1372 * in if necessary, or if a kernel page the caller will at some point
1373 * enter the page into the kernel's pmap. We are not allowed to block
1374 * here so we *can't* do this anyway.
1376 * This routine may not block.
1377 * This routine must be called with the vm_object held.
1378 * This routine must be called with a critical section held.
1380 * This routine returns TRUE if the page was inserted into the object
1381 * successfully, and FALSE if the page already exists in the object.
1384 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex)
1386 ASSERT_LWKT_TOKEN_HELD_EXCL(vm_object_token(object));
1387 if (m->object != NULL)
1388 panic("vm_page_insert: already inserted");
1390 atomic_add_int(&object->generation, 1);
1393 * Record the object/offset pair in this page and add the
1394 * pv_list_count of the page to the object.
1396 * The vm_page spin lock is required for interactions with the pmap.
1398 vm_page_spin_lock(m);
1401 if (vm_page_rb_tree_RB_INSERT(&object->rb_memq, m)) {
1404 vm_page_spin_unlock(m);
1407 ++object->resident_page_count;
1408 ++mycpu->gd_vmtotal.t_rm;
1409 vm_page_spin_unlock(m);
1412 * Since we are inserting a new and possibly dirty page,
1413 * update the object's OBJ_WRITEABLE and OBJ_MIGHTBEDIRTY flags.
1415 if ((m->valid & m->dirty) ||
1416 (m->flags & (PG_WRITEABLE | PG_NEED_COMMIT)))
1417 vm_object_set_writeable_dirty(object);
1420 * Checks for a swap assignment and sets PG_SWAPPED if appropriate.
1422 swap_pager_page_inserted(m);
1427 * Removes the given vm_page_t from the (object,index) table
1429 * The underlying pmap entry (if any) is NOT removed here.
1430 * This routine may not block.
1432 * The page must be BUSY and will remain BUSY on return.
1433 * No other requirements.
1435 * NOTE: FreeBSD side effect was to unbusy the page on return. We leave
1439 vm_page_remove(vm_page_t m)
1443 if (m->object == NULL) {
1447 if ((m->busy_count & PBUSY_LOCKED) == 0)
1448 panic("vm_page_remove: page not busy");
1452 vm_object_hold(object);
1455 * Remove the page from the object and update the object.
1457 * The vm_page spin lock is required for interactions with the pmap.
1459 vm_page_spin_lock(m);
1460 vm_page_rb_tree_RB_REMOVE(&object->rb_memq, m);
1461 --object->resident_page_count;
1462 --mycpu->gd_vmtotal.t_rm;
1464 atomic_add_int(&object->generation, 1);
1465 vm_page_spin_unlock(m);
1467 vm_object_drop(object);
1471 * Calculate the hash position for the vm_page hash heuristic.
1475 vm_page_hash_hash(vm_object_t object, vm_pindex_t pindex)
1479 hi = (uintptr_t)object % (uintptr_t)vm_page_array_size + pindex;
1480 hi %= vm_page_array_size;
1481 return (&vm_page_hash[hi]);
1485 * Heuristical page lookup that does not require any locks. Returns
1486 * a soft-busied page on success, NULL on failure.
1488 * Caller must lookup the page the slow way if NULL is returned.
1491 vm_page_hash_get(vm_object_t object, vm_pindex_t pindex)
1493 struct vm_page **mp;
1496 if (vm_page_hash == NULL)
1498 mp = vm_page_hash_hash(object, pindex);
1503 if (m->object != object || m->pindex != pindex)
1505 if (vm_page_sbusy_try(m))
1507 if (m->object != object || m->pindex != pindex) {
1515 * Enter page onto vm_page_hash[]. This is a heuristic, SMP collisions
1520 vm_page_hash_enter(vm_page_t m)
1522 struct vm_page **mp;
1525 m > &vm_page_array[0] &&
1526 m < &vm_page_array[vm_page_array_size]) {
1527 mp = vm_page_hash_hash(m->object, m->pindex);
1534 * Locate and return the page at (object, pindex), or NULL if the
1535 * page could not be found.
1537 * The caller must hold the vm_object token.
1540 vm_page_lookup(vm_object_t object, vm_pindex_t pindex)
1545 * Search the hash table for this object/offset pair
1547 ASSERT_LWKT_TOKEN_HELD(vm_object_token(object));
1548 m = vm_page_rb_tree_RB_LOOKUP(&object->rb_memq, pindex);
1550 KKASSERT(m->object == object && m->pindex == pindex);
1551 vm_page_hash_enter(m);
1557 VM_PAGE_DEBUG_EXT(vm_page_lookup_busy_wait)(struct vm_object *object,
1559 int also_m_busy, const char *msg
1562 u_int32_t busy_count;
1565 ASSERT_LWKT_TOKEN_HELD(vm_object_token(object));
1566 m = vm_page_rb_tree_RB_LOOKUP(&object->rb_memq, pindex);
1568 KKASSERT(m->object == object && m->pindex == pindex);
1569 busy_count = m->busy_count;
1571 if (busy_count & PBUSY_LOCKED) {
1572 tsleep_interlock(m, 0);
1573 if (atomic_cmpset_int(&m->busy_count, busy_count,
1574 busy_count | PBUSY_WANTED)) {
1575 atomic_set_int(&m->flags, PG_REFERENCED);
1576 tsleep(m, PINTERLOCKED, msg, 0);
1577 m = vm_page_rb_tree_RB_LOOKUP(&object->rb_memq,
1580 } else if (also_m_busy && busy_count) {
1581 tsleep_interlock(m, 0);
1582 if (atomic_cmpset_int(&m->busy_count, busy_count,
1583 busy_count | PBUSY_WANTED)) {
1584 atomic_set_int(&m->flags, PG_REFERENCED);
1585 tsleep(m, PINTERLOCKED, msg, 0);
1586 m = vm_page_rb_tree_RB_LOOKUP(&object->rb_memq,
1589 } else if (atomic_cmpset_int(&m->busy_count, busy_count,
1590 busy_count | PBUSY_LOCKED)) {
1591 #ifdef VM_PAGE_DEBUG
1592 m->busy_func = func;
1593 m->busy_line = lineno;
1595 vm_page_hash_enter(m);
1603 * Attempt to lookup and busy a page.
1605 * Returns NULL if the page could not be found
1607 * Returns a vm_page and error == TRUE if the page exists but could not
1610 * Returns a vm_page and error == FALSE on success.
1613 VM_PAGE_DEBUG_EXT(vm_page_lookup_busy_try)(struct vm_object *object,
1615 int also_m_busy, int *errorp
1618 u_int32_t busy_count;
1621 ASSERT_LWKT_TOKEN_HELD(vm_object_token(object));
1622 m = vm_page_rb_tree_RB_LOOKUP(&object->rb_memq, pindex);
1625 KKASSERT(m->object == object && m->pindex == pindex);
1626 busy_count = m->busy_count;
1628 if (busy_count & PBUSY_LOCKED) {
1632 if (also_m_busy && busy_count) {
1636 if (atomic_cmpset_int(&m->busy_count, busy_count,
1637 busy_count | PBUSY_LOCKED)) {
1638 #ifdef VM_PAGE_DEBUG
1639 m->busy_func = func;
1640 m->busy_line = lineno;
1642 vm_page_hash_enter(m);
1650 * Returns a page that is only soft-busied for use by the caller in
1651 * a read-only fashion. Returns NULL if the page could not be found,
1652 * the soft busy could not be obtained, or the page data is invalid.
1655 vm_page_lookup_sbusy_try(struct vm_object *object, vm_pindex_t pindex,
1656 int pgoff, int pgbytes)
1660 ASSERT_LWKT_TOKEN_HELD(vm_object_token(object));
1661 m = vm_page_rb_tree_RB_LOOKUP(&object->rb_memq, pindex);
1663 if ((m->valid != VM_PAGE_BITS_ALL &&
1664 !vm_page_is_valid(m, pgoff, pgbytes)) ||
1665 (m->flags & PG_FICTITIOUS)) {
1667 } else if (vm_page_sbusy_try(m)) {
1669 } else if ((m->valid != VM_PAGE_BITS_ALL &&
1670 !vm_page_is_valid(m, pgoff, pgbytes)) ||
1671 (m->flags & PG_FICTITIOUS)) {
1672 vm_page_sbusy_drop(m);
1675 vm_page_hash_enter(m);
1682 * Caller must hold the related vm_object
1685 vm_page_next(vm_page_t m)
1689 next = vm_page_rb_tree_RB_NEXT(m);
1690 if (next && next->pindex != m->pindex + 1)
1698 * Move the given vm_page from its current object to the specified
1699 * target object/offset. The page must be busy and will remain so
1702 * new_object must be held.
1703 * This routine might block. XXX ?
1705 * NOTE: Swap associated with the page must be invalidated by the move. We
1706 * have to do this for several reasons: (1) we aren't freeing the
1707 * page, (2) we are dirtying the page, (3) the VM system is probably
1708 * moving the page from object A to B, and will then later move
1709 * the backing store from A to B and we can't have a conflict.
1711 * NOTE: We *always* dirty the page. It is necessary both for the
1712 * fact that we moved it, and because we may be invalidating
1713 * swap. If the page is on the cache, we have to deactivate it
1714 * or vm_page_dirty() will panic. Dirty pages are not allowed
1718 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex)
1720 KKASSERT(m->busy_count & PBUSY_LOCKED);
1721 ASSERT_LWKT_TOKEN_HELD_EXCL(vm_object_token(new_object));
1723 ASSERT_LWKT_TOKEN_HELD_EXCL(vm_object_token(m->object));
1726 if (vm_page_insert(m, new_object, new_pindex) == FALSE) {
1727 panic("vm_page_rename: target exists (%p,%"PRIu64")",
1728 new_object, new_pindex);
1730 if (m->queue - m->pc == PQ_CACHE)
1731 vm_page_deactivate(m);
1736 * vm_page_unqueue() without any wakeup. This routine is used when a page
1737 * is to remain BUSYied by the caller.
1739 * This routine may not block.
1742 vm_page_unqueue_nowakeup(vm_page_t m)
1744 vm_page_and_queue_spin_lock(m);
1745 (void)_vm_page_rem_queue_spinlocked(m);
1746 vm_page_spin_unlock(m);
1750 * vm_page_unqueue() - Remove a page from its queue, wakeup the pagedemon
1753 * This routine may not block.
1756 vm_page_unqueue(vm_page_t m)
1760 vm_page_and_queue_spin_lock(m);
1761 queue = _vm_page_rem_queue_spinlocked(m);
1762 if (queue == PQ_FREE || queue == PQ_CACHE) {
1763 vm_page_spin_unlock(m);
1764 pagedaemon_wakeup();
1766 vm_page_spin_unlock(m);
1771 * vm_page_list_find()
1773 * Find a page on the specified queue with color optimization.
1775 * The page coloring optimization attempts to locate a page that does
1776 * not overload other nearby pages in the object in the cpu's L1 or L2
1777 * caches. We need this optimization because cpu caches tend to be
1778 * physical caches, while object spaces tend to be virtual.
1780 * The page coloring optimization also, very importantly, tries to localize
1781 * memory to cpus and physical sockets.
1783 * Each PQ_FREE and PQ_CACHE color queue has its own spinlock and the
1784 * algorithm is adjusted to localize allocations on a per-core basis.
1785 * This is done by 'twisting' the colors.
1787 * The page is returned spinlocked and removed from its queue (it will
1788 * be on PQ_NONE), or NULL. The page is not BUSY'd. The caller
1789 * is responsible for dealing with the busy-page case (usually by
1790 * deactivating the page and looping).
1792 * NOTE: This routine is carefully inlined. A non-inlined version
1793 * is available for outside callers but the only critical path is
1794 * from within this source file.
1796 * NOTE: This routine assumes that the vm_pages found in PQ_CACHE and PQ_FREE
1797 * represent stable storage, allowing us to order our locks vm_page
1798 * first, then queue.
1802 _vm_page_list_find(int basequeue, int index)
1804 struct vpgqueues *pq;
1807 index &= PQ_L2_MASK;
1808 pq = &vm_page_queues[basequeue + index];
1811 * Try this cpu's colored queue first. Test for a page unlocked,
1812 * then lock the queue and locate a page. Note that the lock order
1813 * is reversed, but we do not want to dwadle on the page spinlock
1814 * anyway as it is held significantly longer than the queue spinlock.
1816 if (TAILQ_FIRST(&pq->pl)) {
1817 spin_lock(&pq->spin);
1818 TAILQ_FOREACH(m, &pq->pl, pageq) {
1819 if (spin_trylock(&m->spin) == 0)
1821 KKASSERT(m->queue == basequeue + index);
1822 _vm_page_rem_queue_spinlocked(m);
1825 spin_unlock(&pq->spin);
1829 * If we are unable to get a page, do a more involved NUMA-aware
1832 m = _vm_page_list_find2(basequeue, index);
1837 * If we could not find the page in the desired queue try to find it in
1838 * a nearby (NUMA-aware) queue.
1841 _vm_page_list_find2(int basequeue, int index)
1843 struct vpgqueues *pq;
1845 int pqmask = PQ_SET_ASSOC_MASK >> 1;
1849 index &= PQ_L2_MASK;
1850 pq = &vm_page_queues[basequeue];
1853 * Run local sets of 16, 32, 64, 128, and the whole queue if all
1854 * else fails (PQ_L2_MASK which is 255).
1856 * Test each queue unlocked first, then lock the queue and locate
1857 * a page. Note that the lock order is reversed, but we do not want
1858 * to dwadle on the page spinlock anyway as it is held significantly
1859 * longer than the queue spinlock.
1862 pqmask = (pqmask << 1) | 1;
1863 for (i = 0; i <= pqmask; ++i) {
1864 pqi = (index & ~pqmask) | ((index + i) & pqmask);
1865 if (TAILQ_FIRST(&pq[pqi].pl)) {
1866 spin_lock(&pq[pqi].spin);
1867 TAILQ_FOREACH(m, &pq[pqi].pl, pageq) {
1868 if (spin_trylock(&m->spin) == 0)
1870 KKASSERT(m->queue == basequeue + pqi);
1871 _vm_page_rem_queue_spinlocked(m);
1874 spin_unlock(&pq[pqi].spin);
1877 } while (pqmask != PQ_L2_MASK);
1883 * Returns a vm_page candidate for allocation. The page is not busied so
1884 * it can move around. The caller must busy the page (and typically
1885 * deactivate it if it cannot be busied!)
1887 * Returns a spinlocked vm_page that has been removed from its queue.
1890 vm_page_list_find(int basequeue, int index)
1892 return(_vm_page_list_find(basequeue, index));
1896 * Find a page on the cache queue with color optimization, remove it
1897 * from the queue, and busy it. The returned page will not be spinlocked.
1899 * A candidate failure will be deactivated. Candidates can fail due to
1900 * being busied by someone else, in which case they will be deactivated.
1902 * This routine may not block.
1906 vm_page_select_cache(u_short pg_color)
1911 m = _vm_page_list_find(PQ_CACHE, pg_color & PQ_L2_MASK);
1915 * (m) has been removed from its queue and spinlocked
1917 if (vm_page_busy_try(m, TRUE)) {
1918 _vm_page_deactivate_locked(m, 0);
1919 vm_page_spin_unlock(m);
1922 * We successfully busied the page
1924 if ((m->flags & (PG_UNMANAGED | PG_NEED_COMMIT)) == 0 &&
1925 m->hold_count == 0 &&
1926 m->wire_count == 0 &&
1927 (m->dirty & m->valid) == 0) {
1928 vm_page_spin_unlock(m);
1929 pagedaemon_wakeup();
1934 * The page cannot be recycled, deactivate it.
1936 _vm_page_deactivate_locked(m, 0);
1937 if (_vm_page_wakeup(m)) {
1938 vm_page_spin_unlock(m);
1941 vm_page_spin_unlock(m);
1949 * Find a free page. We attempt to inline the nominal case and fall back
1950 * to _vm_page_select_free() otherwise. A busied page is removed from
1951 * the queue and returned.
1953 * This routine may not block.
1955 static __inline vm_page_t
1956 vm_page_select_free(u_short pg_color)
1961 m = _vm_page_list_find(PQ_FREE, pg_color & PQ_L2_MASK);
1964 if (vm_page_busy_try(m, TRUE)) {
1966 * Various mechanisms such as a pmap_collect can
1967 * result in a busy page on the free queue. We
1968 * have to move the page out of the way so we can
1969 * retry the allocation. If the other thread is not
1970 * allocating the page then m->valid will remain 0 and
1971 * the pageout daemon will free the page later on.
1973 * Since we could not busy the page, however, we
1974 * cannot make assumptions as to whether the page
1975 * will be allocated by the other thread or not,
1976 * so all we can do is deactivate it to move it out
1977 * of the way. In particular, if the other thread
1978 * wires the page it may wind up on the inactive
1979 * queue and the pageout daemon will have to deal
1980 * with that case too.
1982 _vm_page_deactivate_locked(m, 0);
1983 vm_page_spin_unlock(m);
1986 * Theoretically if we are able to busy the page
1987 * atomic with the queue removal (using the vm_page
1988 * lock) nobody else should have been able to mess
1989 * with the page before us.
1991 * Assert the page state. Note that even though
1992 * wiring doesn't adjust queues, a page on the free
1993 * queue should never be wired at this point.
1995 KKASSERT((m->flags & (PG_UNMANAGED |
1996 PG_NEED_COMMIT)) == 0);
1997 KASSERT(m->hold_count == 0,
1998 ("m->hold_count is not zero "
1999 "pg %p q=%d flags=%08x hold=%d wire=%d",
2000 m, m->queue, m->flags,
2001 m->hold_count, m->wire_count));
2002 KKASSERT(m->wire_count == 0);
2003 vm_page_spin_unlock(m);
2004 pagedaemon_wakeup();
2006 /* return busied and removed page */
2016 * Allocate and return a memory cell associated with this VM object/offset
2017 * pair. If object is NULL an unassociated page will be allocated.
2019 * The returned page will be busied and removed from its queues. This
2020 * routine can block and may return NULL if a race occurs and the page
2021 * is found to already exist at the specified (object, pindex).
2023 * VM_ALLOC_NORMAL allow use of cache pages, nominal free drain
2024 * VM_ALLOC_QUICK like normal but cannot use cache
2025 * VM_ALLOC_SYSTEM greater free drain
2026 * VM_ALLOC_INTERRUPT allow free list to be completely drained
2027 * VM_ALLOC_ZERO advisory request for pre-zero'd page only
2028 * VM_ALLOC_FORCE_ZERO advisory request for pre-zero'd page only
2029 * VM_ALLOC_NULL_OK ok to return NULL on insertion collision
2030 * (see vm_page_grab())
2031 * VM_ALLOC_USE_GD ok to use per-gd cache
2033 * VM_ALLOC_CPU(n) allocate using specified cpu localization
2035 * The object must be held if not NULL
2036 * This routine may not block
2038 * Additional special handling is required when called from an interrupt
2039 * (VM_ALLOC_INTERRUPT). We are not allowed to mess with the page cache
2043 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int page_req)
2053 * Special per-cpu free VM page cache. The pages are pre-busied
2054 * and pre-zerod for us.
2056 if (gd->gd_vmpg_count && (page_req & VM_ALLOC_USE_GD)) {
2058 if (gd->gd_vmpg_count) {
2059 m = gd->gd_vmpg_array[--gd->gd_vmpg_count];
2071 * CPU localization algorithm. Break the page queues up by physical
2072 * id and core id (note that two cpu threads will have the same core
2073 * id, and core_id != gd_cpuid).
2075 * This is nowhere near perfect, for example the last pindex in a
2076 * subgroup will overflow into the next cpu or package. But this
2077 * should get us good page reuse locality in heavy mixed loads.
2079 * (may be executed before the APs are started, so other GDs might
2082 if (page_req & VM_ALLOC_CPU_SPEC)
2083 cpuid_local = VM_ALLOC_GETCPU(page_req);
2085 cpuid_local = mycpu->gd_cpuid;
2087 pg_color = vm_get_pg_color(cpuid_local, object, pindex);
2090 (VM_ALLOC_NORMAL|VM_ALLOC_QUICK|
2091 VM_ALLOC_INTERRUPT|VM_ALLOC_SYSTEM));
2094 * Certain system threads (pageout daemon, buf_daemon's) are
2095 * allowed to eat deeper into the free page list.
2097 if (curthread->td_flags & TDF_SYSTHREAD)
2098 page_req |= VM_ALLOC_SYSTEM;
2101 * Impose various limitations. Note that the v_free_reserved test
2102 * must match the opposite of vm_page_count_target() to avoid
2103 * livelocks, be careful.
2107 if (gd->gd_vmstats.v_free_count >= gd->gd_vmstats.v_free_reserved ||
2108 ((page_req & VM_ALLOC_INTERRUPT) &&
2109 gd->gd_vmstats.v_free_count > 0) ||
2110 ((page_req & VM_ALLOC_SYSTEM) &&
2111 gd->gd_vmstats.v_cache_count == 0 &&
2112 gd->gd_vmstats.v_free_count >
2113 gd->gd_vmstats.v_interrupt_free_min)
2116 * The free queue has sufficient free pages to take one out.
2118 m = vm_page_select_free(pg_color);
2119 } else if (page_req & VM_ALLOC_NORMAL) {
2121 * Allocatable from the cache (non-interrupt only). On
2122 * success, we must free the page and try again, thus
2123 * ensuring that vmstats.v_*_free_min counters are replenished.
2126 if (curthread->td_preempted) {
2127 kprintf("vm_page_alloc(): warning, attempt to allocate"
2128 " cache page from preempting interrupt\n");
2131 m = vm_page_select_cache(pg_color);
2134 m = vm_page_select_cache(pg_color);
2137 * On success move the page into the free queue and loop.
2139 * Only do this if we can safely acquire the vm_object lock,
2140 * because this is effectively a random page and the caller
2141 * might be holding the lock shared, we don't want to
2145 KASSERT(m->dirty == 0,
2146 ("Found dirty cache page %p", m));
2147 if ((obj = m->object) != NULL) {
2148 if (vm_object_hold_try(obj)) {
2149 vm_page_protect(m, VM_PROT_NONE);
2151 /* m->object NULL here */
2152 vm_object_drop(obj);
2154 vm_page_deactivate(m);
2158 vm_page_protect(m, VM_PROT_NONE);
2165 * On failure return NULL
2167 atomic_add_int(&vm_pageout_deficit, 1);
2168 pagedaemon_wakeup();
2172 * No pages available, wakeup the pageout daemon and give up.
2174 atomic_add_int(&vm_pageout_deficit, 1);
2175 pagedaemon_wakeup();
2180 * v_free_count can race so loop if we don't find the expected
2189 * Good page found. The page has already been busied for us and
2190 * removed from its queues.
2192 KASSERT(m->dirty == 0,
2193 ("vm_page_alloc: free/cache page %p was dirty", m));
2194 KKASSERT(m->queue == PQ_NONE);
2200 * Initialize the structure, inheriting some flags but clearing
2201 * all the rest. The page has already been busied for us.
2203 vm_page_flag_clear(m, ~PG_KEEP_NEWPAGE_MASK);
2205 KKASSERT(m->wire_count == 0);
2206 KKASSERT((m->busy_count & PBUSY_MASK) == 0);
2211 * Caller must be holding the object lock (asserted by
2212 * vm_page_insert()).
2214 * NOTE: Inserting a page here does not insert it into any pmaps
2215 * (which could cause us to block allocating memory).
2217 * NOTE: If no object an unassociated page is allocated, m->pindex
2218 * can be used by the caller for any purpose.
2221 if (vm_page_insert(m, object, pindex) == FALSE) {
2223 if ((page_req & VM_ALLOC_NULL_OK) == 0)
2224 panic("PAGE RACE %p[%ld]/%p",
2225 object, (long)pindex, m);
2233 * Don't wakeup too often - wakeup the pageout daemon when
2234 * we would be nearly out of memory.
2236 pagedaemon_wakeup();
2239 * A BUSY page is returned.
2245 * Returns number of pages available in our DMA memory reserve
2246 * (adjusted with vm.dma_reserved=<value>m in /boot/loader.conf)
2249 vm_contig_avail_pages(void)
2254 spin_lock(&vm_contig_spin);
2255 bfree = alist_free_info(&vm_contig_alist, &blk, &count);
2256 spin_unlock(&vm_contig_spin);
2262 * Attempt to allocate contiguous physical memory with the specified
2266 vm_page_alloc_contig(vm_paddr_t low, vm_paddr_t high,
2267 unsigned long alignment, unsigned long boundary,
2268 unsigned long size, vm_memattr_t memattr)
2274 static vm_pindex_t contig_rover;
2277 alignment >>= PAGE_SHIFT;
2280 boundary >>= PAGE_SHIFT;
2283 size = (size + PAGE_MASK) >> PAGE_SHIFT;
2287 * Disabled temporarily until we find a solution for DRM (a flag
2288 * to always use the free space reserve, for performance).
2290 if (high == BUS_SPACE_MAXADDR && alignment <= PAGE_SIZE &&
2291 boundary <= PAGE_SIZE && size == 1 &&
2292 memattr == VM_MEMATTR_DEFAULT) {
2294 * Any page will work, use vm_page_alloc()
2295 * (e.g. when used from kmem_alloc_attr())
2297 m = vm_page_alloc(NULL, (contig_rover++) & 0x7FFFFFFF,
2298 VM_ALLOC_NORMAL | VM_ALLOC_SYSTEM |
2299 VM_ALLOC_INTERRUPT);
2300 m->valid = VM_PAGE_BITS_ALL;
2307 * Use the low-memory dma reserve
2309 spin_lock(&vm_contig_spin);
2310 blk = alist_alloc(&vm_contig_alist, 0, size);
2311 if (blk == ALIST_BLOCK_NONE) {
2312 spin_unlock(&vm_contig_spin);
2314 kprintf("vm_page_alloc_contig: %ldk nospace\n",
2315 (size << PAGE_SHIFT) / 1024);
2320 if (high && ((vm_paddr_t)(blk + size) << PAGE_SHIFT) > high) {
2321 alist_free(&vm_contig_alist, blk, size);
2322 spin_unlock(&vm_contig_spin);
2324 kprintf("vm_page_alloc_contig: %ldk high "
2326 (size << PAGE_SHIFT) / 1024,
2331 spin_unlock(&vm_contig_spin);
2332 m = PHYS_TO_VM_PAGE((vm_paddr_t)blk << PAGE_SHIFT);
2334 if (vm_contig_verbose) {
2335 kprintf("vm_page_alloc_contig: %016jx/%ldk "
2336 "(%016jx-%016jx al=%lu bo=%lu pgs=%lu attr=%d\n",
2337 (intmax_t)m->phys_addr,
2338 (size << PAGE_SHIFT) / 1024,
2339 low, high, alignment, boundary, size, memattr);
2341 if (memattr != VM_MEMATTR_DEFAULT) {
2342 for (i = 0;i < size; i++)
2343 pmap_page_set_memattr(&m[i], memattr);
2349 * Free contiguously allocated pages. The pages will be wired but not busy.
2350 * When freeing to the alist we leave them wired and not busy.
2353 vm_page_free_contig(vm_page_t m, unsigned long size)
2355 vm_paddr_t pa = VM_PAGE_TO_PHYS(m);
2356 vm_pindex_t start = pa >> PAGE_SHIFT;
2357 vm_pindex_t pages = (size + PAGE_MASK) >> PAGE_SHIFT;
2359 if (vm_contig_verbose) {
2360 kprintf("vm_page_free_contig: %016jx/%ldk\n",
2361 (intmax_t)pa, size / 1024);
2363 if (pa < vm_low_phys_reserved) {
2364 KKASSERT(pa + size <= vm_low_phys_reserved);
2365 spin_lock(&vm_contig_spin);
2366 alist_free(&vm_contig_alist, start, pages);
2367 spin_unlock(&vm_contig_spin);
2370 vm_page_busy_wait(m, FALSE, "cpgfr");
2371 vm_page_unwire(m, 0);
2382 * Wait for sufficient free memory for nominal heavy memory use kernel
2385 * WARNING! Be sure never to call this in any vm_pageout code path, which
2386 * will trivially deadlock the system.
2389 vm_wait_nominal(void)
2391 while (vm_page_count_min(0))
2396 * Test if vm_wait_nominal() would block.
2399 vm_test_nominal(void)
2401 if (vm_page_count_min(0))
2407 * Block until free pages are available for allocation, called in various
2408 * places before memory allocations.
2410 * The caller may loop if vm_page_count_min() == FALSE so we cannot be
2411 * more generous then that.
2417 * never wait forever
2421 lwkt_gettoken(&vm_token);
2423 if (curthread == pagethread ||
2424 curthread == emergpager) {
2426 * The pageout daemon itself needs pages, this is bad.
2428 if (vm_page_count_min(0)) {
2429 vm_pageout_pages_needed = 1;
2430 tsleep(&vm_pageout_pages_needed, 0, "VMWait", timo);
2434 * Wakeup the pageout daemon if necessary and wait.
2436 * Do not wait indefinitely for the target to be reached,
2437 * as load might prevent it from being reached any time soon.
2438 * But wait a little to try to slow down page allocations
2439 * and to give more important threads (the pagedaemon)
2440 * allocation priority.
2442 if (vm_page_count_target()) {
2443 if (vm_pages_needed == 0) {
2444 vm_pages_needed = 1;
2445 wakeup(&vm_pages_needed);
2447 ++vm_pages_waiting; /* SMP race ok */
2448 tsleep(&vmstats.v_free_count, 0, "vmwait", timo);
2451 lwkt_reltoken(&vm_token);
2455 * Block until free pages are available for allocation
2457 * Called only from vm_fault so that processes page faulting can be
2461 vm_wait_pfault(void)
2464 * Wakeup the pageout daemon if necessary and wait.
2466 * Do not wait indefinitely for the target to be reached,
2467 * as load might prevent it from being reached any time soon.
2468 * But wait a little to try to slow down page allocations
2469 * and to give more important threads (the pagedaemon)
2470 * allocation priority.
2472 if (vm_page_count_min(0)) {
2473 lwkt_gettoken(&vm_token);
2474 while (vm_page_count_severe()) {
2475 if (vm_page_count_target()) {
2478 if (vm_pages_needed == 0) {
2479 vm_pages_needed = 1;
2480 wakeup(&vm_pages_needed);
2482 ++vm_pages_waiting; /* SMP race ok */
2483 tsleep(&vmstats.v_free_count, 0, "pfault", hz);
2486 * Do not stay stuck in the loop if the system is trying
2487 * to kill the process.
2490 if (td->td_proc && (td->td_proc->p_flags & P_LOWMEMKILL))
2494 lwkt_reltoken(&vm_token);
2499 * Put the specified page on the active list (if appropriate). Ensure
2500 * that act_count is at least ACT_INIT but do not otherwise mess with it.
2502 * The caller should be holding the page busied ? XXX
2503 * This routine may not block.
2506 vm_page_activate(vm_page_t m)
2510 vm_page_spin_lock(m);
2511 if (m->queue - m->pc != PQ_ACTIVE && !(m->flags & PG_FICTITIOUS)) {
2512 _vm_page_queue_spin_lock(m);
2513 oqueue = _vm_page_rem_queue_spinlocked(m);
2514 /* page is left spinlocked, queue is unlocked */
2516 if (oqueue == PQ_CACHE)
2517 mycpu->gd_cnt.v_reactivated++;
2518 if ((m->flags & PG_UNMANAGED) == 0) {
2519 if (m->act_count < ACT_INIT)
2520 m->act_count = ACT_INIT;
2521 _vm_page_add_queue_spinlocked(m, PQ_ACTIVE + m->pc, 0);
2523 _vm_page_and_queue_spin_unlock(m);
2524 if (oqueue == PQ_CACHE || oqueue == PQ_FREE)
2525 pagedaemon_wakeup();
2527 if (m->act_count < ACT_INIT)
2528 m->act_count = ACT_INIT;
2529 vm_page_spin_unlock(m);
2534 * Helper routine for vm_page_free_toq() and vm_page_cache(). This
2535 * routine is called when a page has been added to the cache or free
2538 * This routine may not block.
2540 static __inline void
2541 vm_page_free_wakeup(void)
2543 globaldata_t gd = mycpu;
2546 * If the pageout daemon itself needs pages, then tell it that
2547 * there are some free.
2549 if (vm_pageout_pages_needed &&
2550 gd->gd_vmstats.v_cache_count + gd->gd_vmstats.v_free_count >=
2551 gd->gd_vmstats.v_pageout_free_min
2553 vm_pageout_pages_needed = 0;
2554 wakeup(&vm_pageout_pages_needed);
2558 * Wakeup processes that are waiting on memory.
2560 * Generally speaking we want to wakeup stuck processes as soon as
2561 * possible. !vm_page_count_min(0) is the absolute minimum point
2562 * where we can do this. Wait a bit longer to reduce degenerate
2563 * re-blocking (vm_page_free_hysteresis). The target check is just
2564 * to make sure the min-check w/hysteresis does not exceed the
2567 if (vm_pages_waiting) {
2568 if (!vm_page_count_min(vm_page_free_hysteresis) ||
2569 !vm_page_count_target()) {
2570 vm_pages_waiting = 0;
2571 wakeup(&vmstats.v_free_count);
2572 ++mycpu->gd_cnt.v_ppwakeups;
2575 if (!vm_page_count_target()) {
2577 * Plenty of pages are free, wakeup everyone.
2579 vm_pages_waiting = 0;
2580 wakeup(&vmstats.v_free_count);
2581 ++mycpu->gd_cnt.v_ppwakeups;
2582 } else if (!vm_page_count_min(0)) {
2584 * Some pages are free, wakeup someone.
2586 int wcount = vm_pages_waiting;
2589 vm_pages_waiting = wcount;
2590 wakeup_one(&vmstats.v_free_count);
2591 ++mycpu->gd_cnt.v_ppwakeups;
2598 * Returns the given page to the PQ_FREE or PQ_HOLD list and disassociates
2599 * it from its VM object.
2601 * The vm_page must be BUSY on entry. BUSY will be released on
2602 * return (the page will have been freed).
2605 vm_page_free_toq(vm_page_t m)
2607 mycpu->gd_cnt.v_tfree++;
2608 KKASSERT((m->flags & PG_MAPPED) == 0);
2609 KKASSERT(m->busy_count & PBUSY_LOCKED);
2611 if ((m->busy_count & PBUSY_MASK) || ((m->queue - m->pc) == PQ_FREE)) {
2612 kprintf("vm_page_free: pindex(%lu), busy %08x, "
2614 (u_long)m->pindex, m->busy_count, m->hold_count);
2615 if ((m->queue - m->pc) == PQ_FREE)
2616 panic("vm_page_free: freeing free page");
2618 panic("vm_page_free: freeing busy page");
2622 * Remove from object, spinlock the page and its queues and
2623 * remove from any queue. No queue spinlock will be held
2624 * after this section (because the page was removed from any
2630 * No further management of fictitious pages occurs beyond object
2631 * and queue removal.
2633 if ((m->flags & PG_FICTITIOUS) != 0) {
2634 KKASSERT(m->queue == PQ_NONE);
2638 vm_page_and_queue_spin_lock(m);
2639 _vm_page_rem_queue_spinlocked(m);
2644 if (m->wire_count != 0) {
2645 if (m->wire_count > 1) {
2647 "vm_page_free: invalid wire count (%d), pindex: 0x%lx",
2648 m->wire_count, (long)m->pindex);
2650 panic("vm_page_free: freeing wired page");
2654 * Clear the UNMANAGED flag when freeing an unmanaged page.
2655 * Clear the NEED_COMMIT flag
2657 if (m->flags & PG_UNMANAGED)
2658 vm_page_flag_clear(m, PG_UNMANAGED);
2659 if (m->flags & PG_NEED_COMMIT)
2660 vm_page_flag_clear(m, PG_NEED_COMMIT);
2662 if (m->hold_count != 0) {
2663 _vm_page_add_queue_spinlocked(m, PQ_HOLD + m->pc, 0);
2665 _vm_page_add_queue_spinlocked(m, PQ_FREE + m->pc, 1);
2669 * This sequence allows us to clear BUSY while still holding
2670 * its spin lock, which reduces contention vs allocators. We
2671 * must not leave the queue locked or _vm_page_wakeup() may
2674 _vm_page_queue_spin_unlock(m);
2675 if (_vm_page_wakeup(m)) {
2676 vm_page_spin_unlock(m);
2679 vm_page_spin_unlock(m);
2681 vm_page_free_wakeup();
2685 * vm_page_unmanage()
2687 * Prevent PV management from being done on the page. The page is
2688 * also removed from the paging queues, and as a consequence of no longer
2689 * being managed the pageout daemon will not touch it (since there is no
2690 * way to locate the pte mappings for the page). madvise() calls that
2691 * mess with the pmap will also no longer operate on the page.
2693 * Beyond that the page is still reasonably 'normal'. Freeing the page
2694 * will clear the flag.
2696 * This routine is used by OBJT_PHYS objects - objects using unswappable
2697 * physical memory as backing store rather then swap-backed memory and
2698 * will eventually be extended to support 4MB unmanaged physical
2701 * Caller must be holding the page busy.
2704 vm_page_unmanage(vm_page_t m)
2706 KKASSERT(m->busy_count & PBUSY_LOCKED);
2707 if ((m->flags & PG_UNMANAGED) == 0) {
2710 vm_page_flag_set(m, PG_UNMANAGED);
2714 * Mark this page as wired down by yet another map. We do not adjust the
2715 * queue the page is on, it will be checked for wiring as-needed.
2717 * Caller must be holding the page busy.
2720 vm_page_wire(vm_page_t m)
2723 * Only bump the wire statistics if the page is not already wired,
2724 * and only unqueue the page if it is on some queue (if it is unmanaged
2725 * it is already off the queues). Don't do anything with fictitious
2726 * pages because they are always wired.
2728 KKASSERT(m->busy_count & PBUSY_LOCKED);
2729 if ((m->flags & PG_FICTITIOUS) == 0) {
2730 if (atomic_fetchadd_int(&m->wire_count, 1) == 0) {
2731 atomic_add_long(&mycpu->gd_vmstats_adj.v_wire_count, 1);
2733 KASSERT(m->wire_count != 0,
2734 ("vm_page_wire: wire_count overflow m=%p", m));
2739 * Release one wiring of this page, potentially enabling it to be paged again.
2741 * Note that wired pages are no longer unconditionally removed from the
2742 * paging queues, so the page may already be on a queue. Move the page
2743 * to the desired queue if necessary.
2745 * Many pages placed on the inactive queue should actually go
2746 * into the cache, but it is difficult to figure out which. What
2747 * we do instead, if the inactive target is well met, is to put
2748 * clean pages at the head of the inactive queue instead of the tail.
2749 * This will cause them to be moved to the cache more quickly and
2750 * if not actively re-referenced, freed more quickly. If we just
2751 * stick these pages at the end of the inactive queue, heavy filesystem
2752 * meta-data accesses can cause an unnecessary paging load on memory bound
2753 * processes. This optimization causes one-time-use metadata to be
2754 * reused more quickly.
2756 * Pages marked PG_NEED_COMMIT are always activated and never placed on
2757 * the inactive queue. This helps the pageout daemon determine memory
2758 * pressure and act on out-of-memory situations more quickly.
2760 * BUT, if we are in a low-memory situation we have no choice but to
2761 * put clean pages on the cache queue.
2763 * A number of routines use vm_page_unwire() to guarantee that the page
2764 * will go into either the inactive or active queues, and will NEVER
2765 * be placed in the cache - for example, just after dirtying a page.
2766 * dirty pages in the cache are not allowed.
2768 * This routine may not block.
2771 vm_page_unwire(vm_page_t m, int activate)
2773 KKASSERT(m->busy_count & PBUSY_LOCKED);
2774 if (m->flags & PG_FICTITIOUS) {
2776 } else if ((int)m->wire_count <= 0) {
2777 panic("vm_page_unwire: invalid wire count: %d", m->wire_count);
2779 if (atomic_fetchadd_int(&m->wire_count, -1) == 1) {
2780 atomic_add_long(&mycpu->gd_vmstats_adj.v_wire_count,-1);
2781 if (m->flags & PG_UNMANAGED) {
2783 } else if (activate || (m->flags & PG_NEED_COMMIT)) {
2784 vm_page_activate(m);
2786 vm_page_spin_lock(m);
2787 _vm_page_add_queue_spinlocked(m,
2788 PQ_ACTIVE + m->pc, 0);
2789 _vm_page_and_queue_spin_unlock(m);
2792 vm_page_deactivate(m);
2794 vm_page_spin_lock(m);
2795 vm_page_flag_clear(m, PG_WINATCFLS);
2796 _vm_page_add_queue_spinlocked(m,
2797 PQ_INACTIVE + m->pc, 0);
2798 _vm_page_and_queue_spin_unlock(m);
2806 * Move the specified page to the inactive queue.
2808 * Normally athead is 0 resulting in LRU operation. athead is set
2809 * to 1 if we want this page to be 'as if it were placed in the cache',
2810 * except without unmapping it from the process address space.
2812 * vm_page's spinlock must be held on entry and will remain held on return.
2813 * This routine may not block. The caller does not have to hold the page
2814 * busied but should have some sort of interlock on its validity.
2817 _vm_page_deactivate_locked(vm_page_t m, int athead)
2822 * Ignore if already inactive.
2824 if (m->queue - m->pc == PQ_INACTIVE || (m->flags & PG_FICTITIOUS))
2826 _vm_page_queue_spin_lock(m);
2827 oqueue = _vm_page_rem_queue_spinlocked(m);
2829 if ((m->flags & PG_UNMANAGED) == 0) {
2830 if (oqueue == PQ_CACHE)
2831 mycpu->gd_cnt.v_reactivated++;
2832 vm_page_flag_clear(m, PG_WINATCFLS);
2833 _vm_page_add_queue_spinlocked(m, PQ_INACTIVE + m->pc, athead);
2836 &vm_page_queues[PQ_INACTIVE + m->pc].adds, 1);
2839 /* NOTE: PQ_NONE if condition not taken */
2840 _vm_page_queue_spin_unlock(m);
2841 /* leaves vm_page spinlocked */
2845 * Attempt to deactivate a page.
2850 vm_page_deactivate(vm_page_t m)
2852 vm_page_spin_lock(m);
2853 _vm_page_deactivate_locked(m, 0);
2854 vm_page_spin_unlock(m);
2858 vm_page_deactivate_locked(vm_page_t m)
2860 _vm_page_deactivate_locked(m, 0);
2864 * Attempt to move a busied page to PQ_CACHE, then unconditionally unbusy it.
2866 * This function returns non-zero if it successfully moved the page to
2869 * This function unconditionally unbusies the page on return.
2872 vm_page_try_to_cache(vm_page_t m)
2875 * Shortcut if we obviously cannot move the page, or if the
2876 * page is already on the cache queue, or it is ficitious.
2878 if (m->dirty || m->hold_count || m->wire_count ||
2879 m->queue - m->pc == PQ_CACHE ||
2880 (m->flags & (PG_UNMANAGED | PG_NEED_COMMIT | PG_FICTITIOUS))) {
2886 * Page busied by us and no longer spinlocked. Dirty pages cannot
2887 * be moved to the cache.
2889 vm_page_test_dirty(m);
2890 if (m->dirty || (m->flags & PG_NEED_COMMIT)) {
2899 * Attempt to free the page. If we cannot free it, we do nothing.
2900 * 1 is returned on success, 0 on failure.
2902 * Caller provides an unlocked/non-busied page.
2906 vm_page_try_to_free(vm_page_t m)
2908 if (vm_page_busy_try(m, TRUE))
2912 * The page can be in any state, including already being on the free
2913 * queue. Check to see if it really can be freed.
2915 if (m->dirty || /* can't free if it is dirty */
2916 m->hold_count || /* or held (XXX may be wrong) */
2917 m->wire_count || /* or wired */
2918 (m->flags & (PG_UNMANAGED | /* or unmanaged */
2919 PG_NEED_COMMIT | /* or needs a commit */
2920 PG_FICTITIOUS)) || /* or is fictitious */
2921 m->queue - m->pc == PQ_FREE || /* already on PQ_FREE */
2922 m->queue - m->pc == PQ_HOLD) { /* already on PQ_HOLD */
2928 * We can probably free the page.
2930 * Page busied by us and no longer spinlocked. Dirty pages will
2931 * not be freed by this function. We have to re-test the
2932 * dirty bit after cleaning out the pmaps.
2934 vm_page_test_dirty(m);
2935 if (m->dirty || (m->flags & PG_NEED_COMMIT)) {
2939 vm_page_protect(m, VM_PROT_NONE);
2940 if (m->dirty || (m->flags & PG_NEED_COMMIT)) {
2951 * Put the specified page onto the page cache queue (if appropriate).
2953 * The page must be busy, and this routine will release the busy and
2954 * possibly even free the page.
2957 vm_page_cache(vm_page_t m)
2960 * Not suitable for the cache
2962 if ((m->flags & (PG_UNMANAGED | PG_NEED_COMMIT | PG_FICTITIOUS)) ||
2963 (m->busy_count & PBUSY_MASK) ||
2964 m->wire_count || m->hold_count) {
2970 * Already in the cache (and thus not mapped)
2972 if ((m->queue - m->pc) == PQ_CACHE) {
2973 KKASSERT((m->flags & PG_MAPPED) == 0);
2979 * Caller is required to test m->dirty, but note that the act of
2980 * removing the page from its maps can cause it to become dirty
2981 * on an SMP system due to another cpu running in usermode.
2984 panic("vm_page_cache: caching a dirty page, pindex: %ld",
2989 * Remove all pmaps and indicate that the page is not
2990 * writeable or mapped. Our vm_page_protect() call may
2991 * have blocked (especially w/ VM_PROT_NONE), so recheck
2994 vm_page_protect(m, VM_PROT_NONE);
2995 if ((m->flags & (PG_UNMANAGED | PG_MAPPED)) ||
2996 (m->busy_count & PBUSY_MASK) ||
2997 m->wire_count || m->hold_count) {
2999 } else if (m->dirty || (m->flags & PG_NEED_COMMIT)) {
3000 vm_page_deactivate(m);
3003 _vm_page_and_queue_spin_lock(m);
3004 _vm_page_rem_queue_spinlocked(m);
3005 _vm_page_add_queue_spinlocked(m, PQ_CACHE + m->pc, 0);
3006 _vm_page_and_queue_spin_unlock(m);
3008 vm_page_free_wakeup();
3013 * vm_page_dontneed()
3015 * Cache, deactivate, or do nothing as appropriate. This routine
3016 * is typically used by madvise() MADV_DONTNEED.
3018 * Generally speaking we want to move the page into the cache so
3019 * it gets reused quickly. However, this can result in a silly syndrome
3020 * due to the page recycling too quickly. Small objects will not be
3021 * fully cached. On the otherhand, if we move the page to the inactive
3022 * queue we wind up with a problem whereby very large objects
3023 * unnecessarily blow away our inactive and cache queues.
3025 * The solution is to move the pages based on a fixed weighting. We
3026 * either leave them alone, deactivate them, or move them to the cache,
3027 * where moving them to the cache has the highest weighting.
3028 * By forcing some pages into other queues we eventually force the
3029 * system to balance the queues, potentially recovering other unrelated
3030 * space from active. The idea is to not force this to happen too
3033 * The page must be busied.
3036 vm_page_dontneed(vm_page_t m)
3038 static int dnweight;
3045 * occassionally leave the page alone
3047 if ((dnw & 0x01F0) == 0 ||
3048 m->queue - m->pc == PQ_INACTIVE ||
3049 m->queue - m->pc == PQ_CACHE
3051 if (m->act_count >= ACT_INIT)
3057 * If vm_page_dontneed() is inactivating a page, it must clear
3058 * the referenced flag; otherwise the pagedaemon will see references
3059 * on the page in the inactive queue and reactivate it. Until the
3060 * page can move to the cache queue, madvise's job is not done.
3062 vm_page_flag_clear(m, PG_REFERENCED);
3063 pmap_clear_reference(m);
3066 vm_page_test_dirty(m);
3068 if (m->dirty || (dnw & 0x0070) == 0) {
3070 * Deactivate the page 3 times out of 32.
3075 * Cache the page 28 times out of every 32. Note that
3076 * the page is deactivated instead of cached, but placed
3077 * at the head of the queue instead of the tail.
3081 vm_page_spin_lock(m);
3082 _vm_page_deactivate_locked(m, head);
3083 vm_page_spin_unlock(m);
3087 * These routines manipulate the 'soft busy' count for a page. A soft busy
3088 * is almost like a hard BUSY except that it allows certain compatible
3089 * operations to occur on the page while it is busy. For example, a page
3090 * undergoing a write can still be mapped read-only.
3092 * We also use soft-busy to quickly pmap_enter shared read-only pages
3093 * without having to hold the page locked.
3095 * The soft-busy count can be > 1 in situations where multiple threads
3096 * are pmap_enter()ing the same page simultaneously, or when two buffer
3097 * cache buffers overlap the same page.
3099 * The caller must hold the page BUSY when making these two calls.
3102 vm_page_io_start(vm_page_t m)
3106 ocount = atomic_fetchadd_int(&m->busy_count, 1);
3107 KKASSERT(ocount & PBUSY_LOCKED);
3111 vm_page_io_finish(vm_page_t m)
3115 ocount = atomic_fetchadd_int(&m->busy_count, -1);
3116 KKASSERT(ocount & PBUSY_MASK);
3118 if (((ocount - 1) & (PBUSY_LOCKED | PBUSY_MASK)) == 0)
3124 * Attempt to soft-busy a page. The page must not be PBUSY_LOCKED.
3126 * We can't use fetchadd here because we might race a hard-busy and the
3127 * page freeing code asserts on a non-zero soft-busy count (even if only
3130 * Returns 0 on success, non-zero on failure.
3133 vm_page_sbusy_try(vm_page_t m)
3138 ocount = m->busy_count;
3140 if (ocount & PBUSY_LOCKED)
3142 if (atomic_cmpset_int(&m->busy_count, ocount, ocount + 1))
3147 if (m->busy_count & PBUSY_LOCKED)
3149 ocount = atomic_fetchadd_int(&m->busy_count, 1);
3150 if (ocount & PBUSY_LOCKED) {
3151 vm_page_sbusy_drop(m);
3159 * Indicate that a clean VM page requires a filesystem commit and cannot
3160 * be reused. Used by tmpfs.
3163 vm_page_need_commit(vm_page_t m)
3165 vm_page_flag_set(m, PG_NEED_COMMIT);
3166 vm_object_set_writeable_dirty(m->object);
3170 vm_page_clear_commit(vm_page_t m)
3172 vm_page_flag_clear(m, PG_NEED_COMMIT);
3176 * Grab a page, blocking if it is busy and allocating a page if necessary.
3177 * A busy page is returned or NULL. The page may or may not be valid and
3178 * might not be on a queue (the caller is responsible for the disposition of
3181 * If VM_ALLOC_ZERO is specified and the grab must allocate a new page, the
3182 * page will be zero'd and marked valid.
3184 * If VM_ALLOC_FORCE_ZERO is specified the page will be zero'd and marked
3185 * valid even if it already exists.
3187 * If VM_ALLOC_RETRY is specified this routine will never return NULL. Also
3188 * note that VM_ALLOC_NORMAL must be specified if VM_ALLOC_RETRY is specified.
3189 * VM_ALLOC_NULL_OK is implied when VM_ALLOC_RETRY is specified.
3191 * This routine may block, but if VM_ALLOC_RETRY is not set then NULL is
3192 * always returned if we had blocked.
3194 * This routine may not be called from an interrupt.
3196 * No other requirements.
3199 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags)
3205 KKASSERT(allocflags &
3206 (VM_ALLOC_NORMAL|VM_ALLOC_INTERRUPT|VM_ALLOC_SYSTEM));
3207 vm_object_hold_shared(object);
3209 m = vm_page_lookup_busy_try(object, pindex, TRUE, &error);
3211 vm_page_sleep_busy(m, TRUE, "pgrbwt");
3212 if ((allocflags & VM_ALLOC_RETRY) == 0) {
3217 } else if (m == NULL) {
3219 vm_object_upgrade(object);
3222 if (allocflags & VM_ALLOC_RETRY)
3223 allocflags |= VM_ALLOC_NULL_OK;
3224 m = vm_page_alloc(object, pindex,
3225 allocflags & ~VM_ALLOC_RETRY);
3229 if ((allocflags & VM_ALLOC_RETRY) == 0)
3238 * If VM_ALLOC_ZERO an invalid page will be zero'd and set valid.
3240 * If VM_ALLOC_FORCE_ZERO the page is unconditionally zero'd and set
3241 * valid even if already valid.
3243 * NOTE! We have removed all of the PG_ZERO optimizations and also
3244 * removed the idle zeroing code. These optimizations actually
3245 * slow things down on modern cpus because the zerod area is
3246 * likely uncached, placing a memory-access burden on the
3247 * accesors taking the fault.
3249 * By always zeroing the page in-line with the fault, no
3250 * dynamic ram reads are needed and the caches are hot, ready
3251 * for userland to access the memory.
3253 if (m->valid == 0) {
3254 if (allocflags & (VM_ALLOC_ZERO | VM_ALLOC_FORCE_ZERO)) {
3255 pmap_zero_page(VM_PAGE_TO_PHYS(m));
3256 m->valid = VM_PAGE_BITS_ALL;
3258 } else if (allocflags & VM_ALLOC_FORCE_ZERO) {
3259 pmap_zero_page(VM_PAGE_TO_PHYS(m));
3260 m->valid = VM_PAGE_BITS_ALL;
3263 vm_object_drop(object);
3268 * Mapping function for valid bits or for dirty bits in
3269 * a page. May not block.
3271 * Inputs are required to range within a page.
3277 vm_page_bits(int base, int size)
3283 base + size <= PAGE_SIZE,
3284 ("vm_page_bits: illegal base/size %d/%d", base, size)
3287 if (size == 0) /* handle degenerate case */
3290 first_bit = base >> DEV_BSHIFT;
3291 last_bit = (base + size - 1) >> DEV_BSHIFT;
3293 return ((2 << last_bit) - (1 << first_bit));
3297 * Sets portions of a page valid and clean. The arguments are expected
3298 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive
3299 * of any partial chunks touched by the range. The invalid portion of
3300 * such chunks will be zero'd.
3302 * NOTE: When truncating a buffer vnode_pager_setsize() will automatically
3303 * align base to DEV_BSIZE so as not to mark clean a partially
3304 * truncated device block. Otherwise the dirty page status might be
3307 * This routine may not block.
3309 * (base + size) must be less then or equal to PAGE_SIZE.
3312 _vm_page_zero_valid(vm_page_t m, int base, int size)
3317 if (size == 0) /* handle degenerate case */
3321 * If the base is not DEV_BSIZE aligned and the valid
3322 * bit is clear, we have to zero out a portion of the
3326 if ((frag = base & ~(DEV_BSIZE - 1)) != base &&
3327 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0
3329 pmap_zero_page_area(
3337 * If the ending offset is not DEV_BSIZE aligned and the
3338 * valid bit is clear, we have to zero out a portion of
3342 endoff = base + size;
3344 if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff &&
3345 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0
3347 pmap_zero_page_area(
3350 DEV_BSIZE - (endoff & (DEV_BSIZE - 1))
3356 * Set valid, clear dirty bits. If validating the entire
3357 * page we can safely clear the pmap modify bit. We also
3358 * use this opportunity to clear the PG_NOSYNC flag. If a process
3359 * takes a write fault on a MAP_NOSYNC memory area the flag will
3362 * We set valid bits inclusive of any overlap, but we can only
3363 * clear dirty bits for DEV_BSIZE chunks that are fully within
3366 * Page must be busied?
3367 * No other requirements.
3370 vm_page_set_valid(vm_page_t m, int base, int size)
3372 _vm_page_zero_valid(m, base, size);
3373 m->valid |= vm_page_bits(base, size);
3378 * Set valid bits and clear dirty bits.
3380 * Page must be busied by caller.
3382 * NOTE: This function does not clear the pmap modified bit.
3383 * Also note that e.g. NFS may use a byte-granular base
3386 * No other requirements.
3389 vm_page_set_validclean(vm_page_t m, int base, int size)
3393 _vm_page_zero_valid(m, base, size);
3394 pagebits = vm_page_bits(base, size);
3395 m->valid |= pagebits;
3396 m->dirty &= ~pagebits;
3397 if (base == 0 && size == PAGE_SIZE) {
3398 /*pmap_clear_modify(m);*/
3399 vm_page_flag_clear(m, PG_NOSYNC);
3404 * Set valid & dirty. Used by buwrite()
3406 * Page must be busied by caller.
3409 vm_page_set_validdirty(vm_page_t m, int base, int size)
3413 pagebits = vm_page_bits(base, size);
3414 m->valid |= pagebits;
3415 m->dirty |= pagebits;
3417 vm_object_set_writeable_dirty(m->object);
3423 * NOTE: This function does not clear the pmap modified bit.
3424 * Also note that e.g. NFS may use a byte-granular base
3427 * Page must be busied?
3428 * No other requirements.
3431 vm_page_clear_dirty(vm_page_t m, int base, int size)
3433 m->dirty &= ~vm_page_bits(base, size);
3434 if (base == 0 && size == PAGE_SIZE) {
3435 /*pmap_clear_modify(m);*/
3436 vm_page_flag_clear(m, PG_NOSYNC);
3441 * Make the page all-dirty.
3443 * Also make sure the related object and vnode reflect the fact that the
3444 * object may now contain a dirty page.
3446 * Page must be busied?
3447 * No other requirements.
3450 vm_page_dirty(vm_page_t m)
3453 int pqtype = m->queue - m->pc;
3455 KASSERT(pqtype != PQ_CACHE && pqtype != PQ_FREE,
3456 ("vm_page_dirty: page in free/cache queue!"));
3457 if (m->dirty != VM_PAGE_BITS_ALL) {
3458 m->dirty = VM_PAGE_BITS_ALL;
3460 vm_object_set_writeable_dirty(m->object);
3465 * Invalidates DEV_BSIZE'd chunks within a page. Both the
3466 * valid and dirty bits for the effected areas are cleared.
3468 * Page must be busied?
3470 * No other requirements.
3473 vm_page_set_invalid(vm_page_t m, int base, int size)
3477 bits = vm_page_bits(base, size);
3480 atomic_add_int(&m->object->generation, 1);
3484 * The kernel assumes that the invalid portions of a page contain
3485 * garbage, but such pages can be mapped into memory by user code.
3486 * When this occurs, we must zero out the non-valid portions of the
3487 * page so user code sees what it expects.
3489 * Pages are most often semi-valid when the end of a file is mapped
3490 * into memory and the file's size is not page aligned.
3492 * Page must be busied?
3493 * No other requirements.
3496 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid)
3502 * Scan the valid bits looking for invalid sections that
3503 * must be zerod. Invalid sub-DEV_BSIZE'd areas ( where the
3504 * valid bit may be set ) have already been zerod by
3505 * vm_page_set_validclean().
3507 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) {
3508 if (i == (PAGE_SIZE / DEV_BSIZE) ||
3509 (m->valid & (1 << i))
3512 pmap_zero_page_area(
3515 (i - b) << DEV_BSHIFT
3523 * setvalid is TRUE when we can safely set the zero'd areas
3524 * as being valid. We can do this if there are no cache consistency
3525 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS.
3528 m->valid = VM_PAGE_BITS_ALL;
3532 * Is a (partial) page valid? Note that the case where size == 0
3533 * will return FALSE in the degenerate case where the page is entirely
3534 * invalid, and TRUE otherwise.
3537 * No other requirements.
3540 vm_page_is_valid(vm_page_t m, int base, int size)
3542 int bits = vm_page_bits(base, size);
3544 if (m->valid && ((m->valid & bits) == bits))
3551 * update dirty bits from pmap/mmu. May not block.
3553 * Caller must hold the page busy
3556 vm_page_test_dirty(vm_page_t m)
3558 if ((m->dirty != VM_PAGE_BITS_ALL) && pmap_is_modified(m)) {
3563 #include "opt_ddb.h"
3565 #include <ddb/ddb.h>
3567 DB_SHOW_COMMAND(page, vm_page_print_page_info)
3569 db_printf("vmstats.v_free_count: %ld\n", vmstats.v_free_count);
3570 db_printf("vmstats.v_cache_count: %ld\n", vmstats.v_cache_count);
3571 db_printf("vmstats.v_inactive_count: %ld\n", vmstats.v_inactive_count);
3572 db_printf("vmstats.v_active_count: %ld\n", vmstats.v_active_count);
3573 db_printf("vmstats.v_wire_count: %ld\n", vmstats.v_wire_count);
3574 db_printf("vmstats.v_free_reserved: %ld\n", vmstats.v_free_reserved);
3575 db_printf("vmstats.v_free_min: %ld\n", vmstats.v_free_min);
3576 db_printf("vmstats.v_free_target: %ld\n", vmstats.v_free_target);
3577 db_printf("vmstats.v_cache_min: %ld\n", vmstats.v_cache_min);
3578 db_printf("vmstats.v_inactive_target: %ld\n",
3579 vmstats.v_inactive_target);
3582 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info)
3585 db_printf("PQ_FREE:");
3586 for (i = 0; i < PQ_L2_SIZE; i++) {
3587 db_printf(" %ld", vm_page_queues[PQ_FREE + i].lcnt);
3591 db_printf("PQ_CACHE:");
3592 for(i = 0; i < PQ_L2_SIZE; i++) {
3593 db_printf(" %ld", vm_page_queues[PQ_CACHE + i].lcnt);
3597 db_printf("PQ_ACTIVE:");
3598 for(i = 0; i < PQ_L2_SIZE; i++) {
3599 db_printf(" %ld", vm_page_queues[PQ_ACTIVE + i].lcnt);
3603 db_printf("PQ_INACTIVE:");
3604 for(i = 0; i < PQ_L2_SIZE; i++) {
3605 db_printf(" %ld", vm_page_queues[PQ_INACTIVE + i].lcnt);