1 /*-
2 * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
3 *
4 * Copyright (c) 1991 Regents of the University of California.
5 * All rights reserved.
6 * Copyright (c) 1998 Matthew Dillon. All Rights Reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * The Mach Operating System project at Carnegie-Mellon University.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 /*-
37 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
38 * All rights reserved.
39 *
40 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
41 *
42 * Permission to use, copy, modify and distribute this software and
43 * its documentation is hereby granted, provided that both the copyright
44 * notice and this permission notice appear in all copies of the
45 * software, derivative works or modified versions, and any portions
46 * thereof, and that both notices appear in supporting documentation.
47 *
48 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
49 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
50 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
51 *
52 * Carnegie Mellon requests users of this software to return to
53 *
54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
55 * School of Computer Science
56 * Carnegie Mellon University
57 * Pittsburgh PA 15213-3890
58 *
59 * any improvements or extensions that they make and grant Carnegie the
60 * rights to redistribute these changes.
61 */
62
63 /*
64 * Resident memory management module.
65 */
66
67 #include <sys/cdefs.h>
68 #include "opt_vm.h"
69
70 #include <sys/param.h>
71 #include <sys/systm.h>
72 #include <sys/counter.h>
73 #include <sys/domainset.h>
74 #include <sys/kernel.h>
75 #include <sys/limits.h>
76 #include <sys/linker.h>
77 #include <sys/lock.h>
78 #include <sys/malloc.h>
79 #include <sys/mman.h>
80 #include <sys/msgbuf.h>
81 #include <sys/mutex.h>
82 #include <sys/proc.h>
83 #include <sys/rwlock.h>
84 #include <sys/sleepqueue.h>
85 #include <sys/sbuf.h>
86 #include <sys/sched.h>
87 #include <sys/smp.h>
88 #include <sys/sysctl.h>
89 #include <sys/vmmeter.h>
90 #include <sys/vnode.h>
91
92 #include <vm/vm.h>
93 #include <vm/pmap.h>
94 #include <vm/vm_param.h>
95 #include <vm/vm_domainset.h>
96 #include <vm/vm_kern.h>
97 #include <vm/vm_map.h>
98 #include <vm/vm_object.h>
99 #include <vm/vm_page.h>
100 #include <vm/vm_pageout.h>
101 #include <vm/vm_phys.h>
102 #include <vm/vm_pagequeue.h>
103 #include <vm/vm_pager.h>
104 #include <vm/vm_radix.h>
105 #include <vm/vm_reserv.h>
106 #include <vm/vm_extern.h>
107 #include <vm/vm_dumpset.h>
108 #include <vm/uma.h>
109 #include <vm/uma_int.h>
110
111 #include <machine/md_var.h>
112
113 struct vm_domain vm_dom[MAXMEMDOM];
114
115 DPCPU_DEFINE_STATIC(struct vm_batchqueue, pqbatch[MAXMEMDOM][PQ_COUNT]);
116
117 struct mtx_padalign __exclusive_cache_line pa_lock[PA_LOCK_COUNT];
118
119 struct mtx_padalign __exclusive_cache_line vm_domainset_lock;
120 /* The following fields are protected by the domainset lock. */
121 domainset_t __exclusive_cache_line vm_min_domains;
122 domainset_t __exclusive_cache_line vm_severe_domains;
123 static int vm_min_waiters;
124 static int vm_severe_waiters;
125 static int vm_pageproc_waiters;
126
127 static SYSCTL_NODE(_vm_stats, OID_AUTO, page, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
128 "VM page statistics");
129
130 static COUNTER_U64_DEFINE_EARLY(pqstate_commit_retries);
131 SYSCTL_COUNTER_U64(_vm_stats_page, OID_AUTO, pqstate_commit_retries,
132 CTLFLAG_RD, &pqstate_commit_retries,
133 "Number of failed per-page atomic queue state updates");
134
135 static COUNTER_U64_DEFINE_EARLY(queue_ops);
136 SYSCTL_COUNTER_U64(_vm_stats_page, OID_AUTO, queue_ops,
137 CTLFLAG_RD, &queue_ops,
138 "Number of batched queue operations");
139
140 static COUNTER_U64_DEFINE_EARLY(queue_nops);
141 SYSCTL_COUNTER_U64(_vm_stats_page, OID_AUTO, queue_nops,
142 CTLFLAG_RD, &queue_nops,
143 "Number of batched queue operations with no effects");
144
145 /*
146 * bogus page -- for I/O to/from partially complete buffers,
147 * or for paging into sparsely invalid regions.
148 */
149 vm_page_t bogus_page;
150
151 vm_page_t vm_page_array;
152 long vm_page_array_size;
153 long first_page;
154
155 struct bitset *vm_page_dump;
156 long vm_page_dump_pages;
157
158 static TAILQ_HEAD(, vm_page) blacklist_head;
159 static int sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS);
160 SYSCTL_PROC(_vm, OID_AUTO, page_blacklist, CTLTYPE_STRING | CTLFLAG_RD |
161 CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_page_blacklist, "A", "Blacklist pages");
162
163 static uma_zone_t fakepg_zone;
164
165 static void vm_page_alloc_check(vm_page_t m);
166 static bool _vm_page_busy_sleep(vm_object_t obj, vm_page_t m,
167 vm_pindex_t pindex, const char *wmesg, int allocflags, bool locked);
168 static void vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits);
169 static void vm_page_enqueue(vm_page_t m, uint8_t queue);
170 static bool vm_page_free_prep(vm_page_t m);
171 static void vm_page_free_toq(vm_page_t m);
172 static void vm_page_init(void *dummy);
173 static int vm_page_insert_after(vm_page_t m, vm_object_t object,
174 vm_pindex_t pindex, vm_page_t mpred);
175 static void vm_page_insert_radixdone(vm_page_t m, vm_object_t object,
176 vm_page_t mpred);
177 static void vm_page_mvqueue(vm_page_t m, const uint8_t queue,
178 const uint16_t nflag);
179 static int vm_page_reclaim_run(int req_class, int domain, u_long npages,
180 vm_page_t m_run, vm_paddr_t high);
181 static void vm_page_release_toq(vm_page_t m, uint8_t nqueue, bool noreuse);
182 static int vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object,
183 int req);
184 static int vm_page_zone_import(void *arg, void **store, int cnt, int domain,
185 int flags);
186 static void vm_page_zone_release(void *arg, void **store, int cnt);
187
188 SYSINIT(vm_page, SI_SUB_VM, SI_ORDER_SECOND, vm_page_init, NULL);
189
190 static void
vm_page_init(void * dummy)191 vm_page_init(void *dummy)
192 {
193
194 fakepg_zone = uma_zcreate("fakepg", sizeof(struct vm_page), NULL, NULL,
195 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
196 bogus_page = vm_page_alloc_noobj(VM_ALLOC_WIRED);
197 }
198
199 static int pgcache_zone_max_pcpu;
200 SYSCTL_INT(_vm, OID_AUTO, pgcache_zone_max_pcpu,
201 CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &pgcache_zone_max_pcpu, 0,
202 "Per-CPU page cache size");
203
204 /*
205 * The cache page zone is initialized later since we need to be able to allocate
206 * pages before UMA is fully initialized.
207 */
208 static void
vm_page_init_cache_zones(void * dummy __unused)209 vm_page_init_cache_zones(void *dummy __unused)
210 {
211 struct vm_domain *vmd;
212 struct vm_pgcache *pgcache;
213 int cache, domain, maxcache, pool;
214
215 TUNABLE_INT_FETCH("vm.pgcache_zone_max_pcpu", &pgcache_zone_max_pcpu);
216 maxcache = pgcache_zone_max_pcpu * mp_ncpus;
217 for (domain = 0; domain < vm_ndomains; domain++) {
218 vmd = VM_DOMAIN(domain);
219 for (pool = 0; pool < VM_NFREEPOOL; pool++) {
220 pgcache = &vmd->vmd_pgcache[pool];
221 pgcache->domain = domain;
222 pgcache->pool = pool;
223 pgcache->zone = uma_zcache_create("vm pgcache",
224 PAGE_SIZE, NULL, NULL, NULL, NULL,
225 vm_page_zone_import, vm_page_zone_release, pgcache,
226 UMA_ZONE_VM);
227
228 /*
229 * Limit each pool's zone to 0.1% of the pages in the
230 * domain.
231 */
232 cache = maxcache != 0 ? maxcache :
233 vmd->vmd_page_count / 1000;
234 uma_zone_set_maxcache(pgcache->zone, cache);
235 }
236 }
237 }
238 SYSINIT(vm_page2, SI_SUB_VM_CONF, SI_ORDER_ANY, vm_page_init_cache_zones, NULL);
239
240 /* Make sure that u_long is at least 64 bits when PAGE_SIZE is 32K. */
241 #if PAGE_SIZE == 32768
242 #ifdef CTASSERT
243 CTASSERT(sizeof(u_long) >= 8);
244 #endif
245 #endif
246
247 /*
248 * vm_set_page_size:
249 *
250 * Sets the page size, perhaps based upon the memory
251 * size. Must be called before any use of page-size
252 * dependent functions.
253 */
254 void
vm_set_page_size(void)255 vm_set_page_size(void)
256 {
257 if (vm_cnt.v_page_size == 0)
258 vm_cnt.v_page_size = PAGE_SIZE;
259 if (((vm_cnt.v_page_size - 1) & vm_cnt.v_page_size) != 0)
260 panic("vm_set_page_size: page size not a power of two");
261 }
262
263 /*
264 * vm_page_blacklist_next:
265 *
266 * Find the next entry in the provided string of blacklist
267 * addresses. Entries are separated by space, comma, or newline.
268 * If an invalid integer is encountered then the rest of the
269 * string is skipped. Updates the list pointer to the next
270 * character, or NULL if the string is exhausted or invalid.
271 */
272 static vm_paddr_t
vm_page_blacklist_next(char ** list,char * end)273 vm_page_blacklist_next(char **list, char *end)
274 {
275 vm_paddr_t bad;
276 char *cp, *pos;
277
278 if (list == NULL || *list == NULL)
279 return (0);
280 if (**list =='\0') {
281 *list = NULL;
282 return (0);
283 }
284
285 /*
286 * If there's no end pointer then the buffer is coming from
287 * the kenv and we know it's null-terminated.
288 */
289 if (end == NULL)
290 end = *list + strlen(*list);
291
292 /* Ensure that strtoq() won't walk off the end */
293 if (*end != '\0') {
294 if (*end == '\n' || *end == ' ' || *end == ',')
295 *end = '\0';
296 else {
297 printf("Blacklist not terminated, skipping\n");
298 *list = NULL;
299 return (0);
300 }
301 }
302
303 for (pos = *list; *pos != '\0'; pos = cp) {
304 bad = strtoq(pos, &cp, 0);
305 if (*cp == '\0' || *cp == ' ' || *cp == ',' || *cp == '\n') {
306 if (bad == 0) {
307 if (++cp < end)
308 continue;
309 else
310 break;
311 }
312 } else
313 break;
314 if (*cp == '\0' || ++cp >= end)
315 *list = NULL;
316 else
317 *list = cp;
318 return (trunc_page(bad));
319 }
320 printf("Garbage in RAM blacklist, skipping\n");
321 *list = NULL;
322 return (0);
323 }
324
325 bool
vm_page_blacklist_add(vm_paddr_t pa,bool verbose)326 vm_page_blacklist_add(vm_paddr_t pa, bool verbose)
327 {
328 struct vm_domain *vmd;
329 vm_page_t m;
330 bool found;
331
332 m = vm_phys_paddr_to_vm_page(pa);
333 if (m == NULL)
334 return (true); /* page does not exist, no failure */
335
336 vmd = vm_pagequeue_domain(m);
337 vm_domain_free_lock(vmd);
338 found = vm_phys_unfree_page(m);
339 vm_domain_free_unlock(vmd);
340 if (found) {
341 vm_domain_freecnt_inc(vmd, -1);
342 TAILQ_INSERT_TAIL(&blacklist_head, m, listq);
343 if (verbose)
344 printf("Skipping page with pa 0x%jx\n", (uintmax_t)pa);
345 }
346 return (found);
347 }
348
349 /*
350 * vm_page_blacklist_check:
351 *
352 * Iterate through the provided string of blacklist addresses, pulling
353 * each entry out of the physical allocator free list and putting it
354 * onto a list for reporting via the vm.page_blacklist sysctl.
355 */
356 static void
vm_page_blacklist_check(char * list,char * end)357 vm_page_blacklist_check(char *list, char *end)
358 {
359 vm_paddr_t pa;
360 char *next;
361
362 next = list;
363 while (next != NULL) {
364 if ((pa = vm_page_blacklist_next(&next, end)) == 0)
365 continue;
366 vm_page_blacklist_add(pa, bootverbose);
367 }
368 }
369
370 /*
371 * vm_page_blacklist_load:
372 *
373 * Search for a special module named "ram_blacklist". It'll be a
374 * plain text file provided by the user via the loader directive
375 * of the same name.
376 */
377 static void
vm_page_blacklist_load(char ** list,char ** end)378 vm_page_blacklist_load(char **list, char **end)
379 {
380 void *mod;
381 u_char *ptr;
382 u_int len;
383
384 mod = NULL;
385 ptr = NULL;
386
387 mod = preload_search_by_type("ram_blacklist");
388 if (mod != NULL) {
389 ptr = preload_fetch_addr(mod);
390 len = preload_fetch_size(mod);
391 }
392 *list = ptr;
393 if (ptr != NULL)
394 *end = ptr + len;
395 else
396 *end = NULL;
397 return;
398 }
399
400 static int
sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS)401 sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS)
402 {
403 vm_page_t m;
404 struct sbuf sbuf;
405 int error, first;
406
407 first = 1;
408 error = sysctl_wire_old_buffer(req, 0);
409 if (error != 0)
410 return (error);
411 sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
412 TAILQ_FOREACH(m, &blacklist_head, listq) {
413 sbuf_printf(&sbuf, "%s%#jx", first ? "" : ",",
414 (uintmax_t)m->phys_addr);
415 first = 0;
416 }
417 error = sbuf_finish(&sbuf);
418 sbuf_delete(&sbuf);
419 return (error);
420 }
421
422 /*
423 * Initialize a dummy page for use in scans of the specified paging queue.
424 * In principle, this function only needs to set the flag PG_MARKER.
425 * Nonetheless, it write busies the page as a safety precaution.
426 */
427 void
vm_page_init_marker(vm_page_t marker,int queue,uint16_t aflags)428 vm_page_init_marker(vm_page_t marker, int queue, uint16_t aflags)
429 {
430
431 bzero(marker, sizeof(*marker));
432 marker->flags = PG_MARKER;
433 marker->a.flags = aflags;
434 marker->busy_lock = VPB_CURTHREAD_EXCLUSIVE;
435 marker->a.queue = queue;
436 }
437
438 static void
vm_page_domain_init(int domain)439 vm_page_domain_init(int domain)
440 {
441 struct vm_domain *vmd;
442 struct vm_pagequeue *pq;
443 int i;
444
445 vmd = VM_DOMAIN(domain);
446 bzero(vmd, sizeof(*vmd));
447 *__DECONST(const char **, &vmd->vmd_pagequeues[PQ_INACTIVE].pq_name) =
448 "vm inactive pagequeue";
449 *__DECONST(const char **, &vmd->vmd_pagequeues[PQ_ACTIVE].pq_name) =
450 "vm active pagequeue";
451 *__DECONST(const char **, &vmd->vmd_pagequeues[PQ_LAUNDRY].pq_name) =
452 "vm laundry pagequeue";
453 *__DECONST(const char **,
454 &vmd->vmd_pagequeues[PQ_UNSWAPPABLE].pq_name) =
455 "vm unswappable pagequeue";
456 vmd->vmd_domain = domain;
457 vmd->vmd_page_count = 0;
458 vmd->vmd_free_count = 0;
459 vmd->vmd_segs = 0;
460 vmd->vmd_oom = FALSE;
461 for (i = 0; i < PQ_COUNT; i++) {
462 pq = &vmd->vmd_pagequeues[i];
463 TAILQ_INIT(&pq->pq_pl);
464 mtx_init(&pq->pq_mutex, pq->pq_name, "vm pagequeue",
465 MTX_DEF | MTX_DUPOK);
466 pq->pq_pdpages = 0;
467 vm_page_init_marker(&vmd->vmd_markers[i], i, 0);
468 }
469 mtx_init(&vmd->vmd_free_mtx, "vm page free queue", NULL, MTX_DEF);
470 mtx_init(&vmd->vmd_pageout_mtx, "vm pageout lock", NULL, MTX_DEF);
471 snprintf(vmd->vmd_name, sizeof(vmd->vmd_name), "%d", domain);
472
473 /*
474 * inacthead is used to provide FIFO ordering for LRU-bypassing
475 * insertions.
476 */
477 vm_page_init_marker(&vmd->vmd_inacthead, PQ_INACTIVE, PGA_ENQUEUED);
478 TAILQ_INSERT_HEAD(&vmd->vmd_pagequeues[PQ_INACTIVE].pq_pl,
479 &vmd->vmd_inacthead, plinks.q);
480
481 /*
482 * The clock pages are used to implement active queue scanning without
483 * requeues. Scans start at clock[0], which is advanced after the scan
484 * ends. When the two clock hands meet, they are reset and scanning
485 * resumes from the head of the queue.
486 */
487 vm_page_init_marker(&vmd->vmd_clock[0], PQ_ACTIVE, PGA_ENQUEUED);
488 vm_page_init_marker(&vmd->vmd_clock[1], PQ_ACTIVE, PGA_ENQUEUED);
489 TAILQ_INSERT_HEAD(&vmd->vmd_pagequeues[PQ_ACTIVE].pq_pl,
490 &vmd->vmd_clock[0], plinks.q);
491 TAILQ_INSERT_TAIL(&vmd->vmd_pagequeues[PQ_ACTIVE].pq_pl,
492 &vmd->vmd_clock[1], plinks.q);
493 }
494
495 /*
496 * Initialize a physical page in preparation for adding it to the free
497 * lists.
498 */
499 void
vm_page_init_page(vm_page_t m,vm_paddr_t pa,int segind)500 vm_page_init_page(vm_page_t m, vm_paddr_t pa, int segind)
501 {
502
503 m->object = NULL;
504 m->ref_count = 0;
505 m->busy_lock = VPB_FREED;
506 m->flags = m->a.flags = 0;
507 m->phys_addr = pa;
508 m->a.queue = PQ_NONE;
509 m->psind = 0;
510 m->segind = segind;
511 m->order = VM_NFREEORDER;
512 m->pool = VM_FREEPOOL_DEFAULT;
513 m->valid = m->dirty = 0;
514 pmap_page_init(m);
515 }
516
517 #ifndef PMAP_HAS_PAGE_ARRAY
518 static vm_paddr_t
vm_page_array_alloc(vm_offset_t * vaddr,vm_paddr_t end,vm_paddr_t page_range)519 vm_page_array_alloc(vm_offset_t *vaddr, vm_paddr_t end, vm_paddr_t page_range)
520 {
521 vm_paddr_t new_end;
522
523 /*
524 * Reserve an unmapped guard page to trap access to vm_page_array[-1].
525 * However, because this page is allocated from KVM, out-of-bounds
526 * accesses using the direct map will not be trapped.
527 */
528 *vaddr += PAGE_SIZE;
529
530 /*
531 * Allocate physical memory for the page structures, and map it.
532 */
533 new_end = trunc_page(end - page_range * sizeof(struct vm_page));
534 vm_page_array = (vm_page_t)pmap_map(vaddr, new_end, end,
535 VM_PROT_READ | VM_PROT_WRITE);
536 vm_page_array_size = page_range;
537
538 return (new_end);
539 }
540 #endif
541
542 /*
543 * vm_page_startup:
544 *
545 * Initializes the resident memory module. Allocates physical memory for
546 * bootstrapping UMA and some data structures that are used to manage
547 * physical pages. Initializes these structures, and populates the free
548 * page queues.
549 */
550 vm_offset_t
vm_page_startup(vm_offset_t vaddr)551 vm_page_startup(vm_offset_t vaddr)
552 {
553 struct vm_phys_seg *seg;
554 struct vm_domain *vmd;
555 vm_page_t m;
556 char *list, *listend;
557 vm_paddr_t end, high_avail, low_avail, new_end, size;
558 vm_paddr_t page_range __unused;
559 vm_paddr_t last_pa, pa, startp, endp;
560 u_long pagecount;
561 #if MINIDUMP_PAGE_TRACKING
562 u_long vm_page_dump_size;
563 #endif
564 int biggestone, i, segind;
565 #ifdef WITNESS
566 vm_offset_t mapped;
567 int witness_size;
568 #endif
569 #if defined(__i386__) && defined(VM_PHYSSEG_DENSE)
570 long ii;
571 #endif
572
573 vaddr = round_page(vaddr);
574
575 vm_phys_early_startup();
576 biggestone = vm_phys_avail_largest();
577 end = phys_avail[biggestone+1];
578
579 /*
580 * Initialize the page and queue locks.
581 */
582 mtx_init(&vm_domainset_lock, "vm domainset lock", NULL, MTX_DEF);
583 for (i = 0; i < PA_LOCK_COUNT; i++)
584 mtx_init(&pa_lock[i], "vm page", NULL, MTX_DEF);
585 for (i = 0; i < vm_ndomains; i++)
586 vm_page_domain_init(i);
587
588 new_end = end;
589 #ifdef WITNESS
590 witness_size = round_page(witness_startup_count());
591 new_end -= witness_size;
592 mapped = pmap_map(&vaddr, new_end, new_end + witness_size,
593 VM_PROT_READ | VM_PROT_WRITE);
594 bzero((void *)mapped, witness_size);
595 witness_startup((void *)mapped);
596 #endif
597
598 #if MINIDUMP_PAGE_TRACKING
599 /*
600 * Allocate a bitmap to indicate that a random physical page
601 * needs to be included in a minidump.
602 *
603 * The amd64 port needs this to indicate which direct map pages
604 * need to be dumped, via calls to dump_add_page()/dump_drop_page().
605 *
606 * However, i386 still needs this workspace internally within the
607 * minidump code. In theory, they are not needed on i386, but are
608 * included should the sf_buf code decide to use them.
609 */
610 last_pa = 0;
611 vm_page_dump_pages = 0;
612 for (i = 0; dump_avail[i + 1] != 0; i += 2) {
613 vm_page_dump_pages += howmany(dump_avail[i + 1], PAGE_SIZE) -
614 dump_avail[i] / PAGE_SIZE;
615 if (dump_avail[i + 1] > last_pa)
616 last_pa = dump_avail[i + 1];
617 }
618 vm_page_dump_size = round_page(BITSET_SIZE(vm_page_dump_pages));
619 new_end -= vm_page_dump_size;
620 vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end,
621 new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE);
622 bzero((void *)vm_page_dump, vm_page_dump_size);
623 #if MINIDUMP_STARTUP_PAGE_TRACKING
624 /*
625 * Include the UMA bootstrap pages, witness pages and vm_page_dump
626 * in a crash dump. When pmap_map() uses the direct map, they are
627 * not automatically included.
628 */
629 for (pa = new_end; pa < end; pa += PAGE_SIZE)
630 dump_add_page(pa);
631 #endif
632 #else
633 (void)last_pa;
634 #endif
635 phys_avail[biggestone + 1] = new_end;
636 #ifdef __amd64__
637 /*
638 * Request that the physical pages underlying the message buffer be
639 * included in a crash dump. Since the message buffer is accessed
640 * through the direct map, they are not automatically included.
641 */
642 pa = DMAP_TO_PHYS((vm_offset_t)msgbufp->msg_ptr);
643 last_pa = pa + round_page(msgbufsize);
644 while (pa < last_pa) {
645 dump_add_page(pa);
646 pa += PAGE_SIZE;
647 }
648 #endif
649 /*
650 * Compute the number of pages of memory that will be available for
651 * use, taking into account the overhead of a page structure per page.
652 * In other words, solve
653 * "available physical memory" - round_page(page_range *
654 * sizeof(struct vm_page)) = page_range * PAGE_SIZE
655 * for page_range.
656 */
657 low_avail = phys_avail[0];
658 high_avail = phys_avail[1];
659 for (i = 0; i < vm_phys_nsegs; i++) {
660 if (vm_phys_segs[i].start < low_avail)
661 low_avail = vm_phys_segs[i].start;
662 if (vm_phys_segs[i].end > high_avail)
663 high_avail = vm_phys_segs[i].end;
664 }
665 /* Skip the first chunk. It is already accounted for. */
666 for (i = 2; phys_avail[i + 1] != 0; i += 2) {
667 if (phys_avail[i] < low_avail)
668 low_avail = phys_avail[i];
669 if (phys_avail[i + 1] > high_avail)
670 high_avail = phys_avail[i + 1];
671 }
672 first_page = low_avail / PAGE_SIZE;
673 #ifdef VM_PHYSSEG_SPARSE
674 size = 0;
675 for (i = 0; i < vm_phys_nsegs; i++)
676 size += vm_phys_segs[i].end - vm_phys_segs[i].start;
677 for (i = 0; phys_avail[i + 1] != 0; i += 2)
678 size += phys_avail[i + 1] - phys_avail[i];
679 #elif defined(VM_PHYSSEG_DENSE)
680 size = high_avail - low_avail;
681 #else
682 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined."
683 #endif
684
685 #ifdef PMAP_HAS_PAGE_ARRAY
686 pmap_page_array_startup(size / PAGE_SIZE);
687 biggestone = vm_phys_avail_largest();
688 end = new_end = phys_avail[biggestone + 1];
689 #else
690 #ifdef VM_PHYSSEG_DENSE
691 /*
692 * In the VM_PHYSSEG_DENSE case, the number of pages can account for
693 * the overhead of a page structure per page only if vm_page_array is
694 * allocated from the last physical memory chunk. Otherwise, we must
695 * allocate page structures representing the physical memory
696 * underlying vm_page_array, even though they will not be used.
697 */
698 if (new_end != high_avail)
699 page_range = size / PAGE_SIZE;
700 else
701 #endif
702 {
703 page_range = size / (PAGE_SIZE + sizeof(struct vm_page));
704
705 /*
706 * If the partial bytes remaining are large enough for
707 * a page (PAGE_SIZE) without a corresponding
708 * 'struct vm_page', then new_end will contain an
709 * extra page after subtracting the length of the VM
710 * page array. Compensate by subtracting an extra
711 * page from new_end.
712 */
713 if (size % (PAGE_SIZE + sizeof(struct vm_page)) >= PAGE_SIZE) {
714 if (new_end == high_avail)
715 high_avail -= PAGE_SIZE;
716 new_end -= PAGE_SIZE;
717 }
718 }
719 end = new_end;
720 new_end = vm_page_array_alloc(&vaddr, end, page_range);
721 #endif
722
723 #if VM_NRESERVLEVEL > 0
724 /*
725 * Allocate physical memory for the reservation management system's
726 * data structures, and map it.
727 */
728 new_end = vm_reserv_startup(&vaddr, new_end);
729 #endif
730 #if MINIDUMP_PAGE_TRACKING && MINIDUMP_STARTUP_PAGE_TRACKING
731 /*
732 * Include vm_page_array and vm_reserv_array in a crash dump.
733 */
734 for (pa = new_end; pa < end; pa += PAGE_SIZE)
735 dump_add_page(pa);
736 #endif
737 phys_avail[biggestone + 1] = new_end;
738
739 /*
740 * Add physical memory segments corresponding to the available
741 * physical pages.
742 */
743 for (i = 0; phys_avail[i + 1] != 0; i += 2)
744 if (vm_phys_avail_size(i) != 0)
745 vm_phys_add_seg(phys_avail[i], phys_avail[i + 1]);
746
747 /*
748 * Initialize the physical memory allocator.
749 */
750 vm_phys_init();
751
752 /*
753 * Initialize the page structures and add every available page to the
754 * physical memory allocator's free lists.
755 */
756 #if defined(__i386__) && defined(VM_PHYSSEG_DENSE)
757 for (ii = 0; ii < vm_page_array_size; ii++) {
758 m = &vm_page_array[ii];
759 vm_page_init_page(m, (first_page + ii) << PAGE_SHIFT, 0);
760 m->flags = PG_FICTITIOUS;
761 }
762 #endif
763 vm_cnt.v_page_count = 0;
764 for (segind = 0; segind < vm_phys_nsegs; segind++) {
765 seg = &vm_phys_segs[segind];
766 for (m = seg->first_page, pa = seg->start; pa < seg->end;
767 m++, pa += PAGE_SIZE)
768 vm_page_init_page(m, pa, segind);
769
770 /*
771 * Add the segment's pages that are covered by one of
772 * phys_avail's ranges to the free lists.
773 */
774 for (i = 0; phys_avail[i + 1] != 0; i += 2) {
775 if (seg->end <= phys_avail[i] ||
776 seg->start >= phys_avail[i + 1])
777 continue;
778
779 startp = MAX(seg->start, phys_avail[i]);
780 endp = MIN(seg->end, phys_avail[i + 1]);
781 pagecount = (u_long)atop(endp - startp);
782 if (pagecount == 0)
783 continue;
784
785 m = seg->first_page + atop(startp - seg->start);
786 vmd = VM_DOMAIN(seg->domain);
787 vm_domain_free_lock(vmd);
788 vm_phys_enqueue_contig(m, pagecount);
789 vm_domain_free_unlock(vmd);
790 vm_domain_freecnt_inc(vmd, pagecount);
791 vm_cnt.v_page_count += (u_int)pagecount;
792 vmd->vmd_page_count += (u_int)pagecount;
793 vmd->vmd_segs |= 1UL << segind;
794 }
795 }
796
797 /*
798 * Remove blacklisted pages from the physical memory allocator.
799 */
800 TAILQ_INIT(&blacklist_head);
801 vm_page_blacklist_load(&list, &listend);
802 vm_page_blacklist_check(list, listend);
803
804 list = kern_getenv("vm.blacklist");
805 vm_page_blacklist_check(list, NULL);
806
807 freeenv(list);
808 #if VM_NRESERVLEVEL > 0
809 /*
810 * Initialize the reservation management system.
811 */
812 vm_reserv_init();
813 #endif
814
815 return (vaddr);
816 }
817
818 void
vm_page_reference(vm_page_t m)819 vm_page_reference(vm_page_t m)
820 {
821
822 vm_page_aflag_set(m, PGA_REFERENCED);
823 }
824
825 /*
826 * vm_page_trybusy
827 *
828 * Helper routine for grab functions to trylock busy.
829 *
830 * Returns true on success and false on failure.
831 */
832 static bool
vm_page_trybusy(vm_page_t m,int allocflags)833 vm_page_trybusy(vm_page_t m, int allocflags)
834 {
835
836 if ((allocflags & (VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY)) != 0)
837 return (vm_page_trysbusy(m));
838 else
839 return (vm_page_tryxbusy(m));
840 }
841
842 /*
843 * vm_page_tryacquire
844 *
845 * Helper routine for grab functions to trylock busy and wire.
846 *
847 * Returns true on success and false on failure.
848 */
849 static inline bool
vm_page_tryacquire(vm_page_t m,int allocflags)850 vm_page_tryacquire(vm_page_t m, int allocflags)
851 {
852 bool locked;
853
854 locked = vm_page_trybusy(m, allocflags);
855 if (locked && (allocflags & VM_ALLOC_WIRED) != 0)
856 vm_page_wire(m);
857 return (locked);
858 }
859
860 /*
861 * vm_page_busy_acquire:
862 *
863 * Acquire the busy lock as described by VM_ALLOC_* flags. Will loop
864 * and drop the object lock if necessary.
865 */
866 bool
vm_page_busy_acquire(vm_page_t m,int allocflags)867 vm_page_busy_acquire(vm_page_t m, int allocflags)
868 {
869 vm_object_t obj;
870 bool locked;
871
872 /*
873 * The page-specific object must be cached because page
874 * identity can change during the sleep, causing the
875 * re-lock of a different object.
876 * It is assumed that a reference to the object is already
877 * held by the callers.
878 */
879 obj = atomic_load_ptr(&m->object);
880 for (;;) {
881 if (vm_page_tryacquire(m, allocflags))
882 return (true);
883 if ((allocflags & VM_ALLOC_NOWAIT) != 0)
884 return (false);
885 if (obj != NULL)
886 locked = VM_OBJECT_WOWNED(obj);
887 else
888 locked = false;
889 MPASS(locked || vm_page_wired(m));
890 if (_vm_page_busy_sleep(obj, m, m->pindex, "vmpba", allocflags,
891 locked) && locked)
892 VM_OBJECT_WLOCK(obj);
893 if ((allocflags & VM_ALLOC_WAITFAIL) != 0)
894 return (false);
895 KASSERT(m->object == obj || m->object == NULL,
896 ("vm_page_busy_acquire: page %p does not belong to %p",
897 m, obj));
898 }
899 }
900
901 /*
902 * vm_page_busy_downgrade:
903 *
904 * Downgrade an exclusive busy page into a single shared busy page.
905 */
906 void
vm_page_busy_downgrade(vm_page_t m)907 vm_page_busy_downgrade(vm_page_t m)
908 {
909 u_int x;
910
911 vm_page_assert_xbusied(m);
912
913 x = vm_page_busy_fetch(m);
914 for (;;) {
915 if (atomic_fcmpset_rel_int(&m->busy_lock,
916 &x, VPB_SHARERS_WORD(1)))
917 break;
918 }
919 if ((x & VPB_BIT_WAITERS) != 0)
920 wakeup(m);
921 }
922
923 /*
924 *
925 * vm_page_busy_tryupgrade:
926 *
927 * Attempt to upgrade a single shared busy into an exclusive busy.
928 */
929 int
vm_page_busy_tryupgrade(vm_page_t m)930 vm_page_busy_tryupgrade(vm_page_t m)
931 {
932 u_int ce, x;
933
934 vm_page_assert_sbusied(m);
935
936 x = vm_page_busy_fetch(m);
937 ce = VPB_CURTHREAD_EXCLUSIVE;
938 for (;;) {
939 if (VPB_SHARERS(x) > 1)
940 return (0);
941 KASSERT((x & ~VPB_BIT_WAITERS) == VPB_SHARERS_WORD(1),
942 ("vm_page_busy_tryupgrade: invalid lock state"));
943 if (!atomic_fcmpset_acq_int(&m->busy_lock, &x,
944 ce | (x & VPB_BIT_WAITERS)))
945 continue;
946 return (1);
947 }
948 }
949
950 /*
951 * vm_page_sbusied:
952 *
953 * Return a positive value if the page is shared busied, 0 otherwise.
954 */
955 int
vm_page_sbusied(vm_page_t m)956 vm_page_sbusied(vm_page_t m)
957 {
958 u_int x;
959
960 x = vm_page_busy_fetch(m);
961 return ((x & VPB_BIT_SHARED) != 0 && x != VPB_UNBUSIED);
962 }
963
964 /*
965 * vm_page_sunbusy:
966 *
967 * Shared unbusy a page.
968 */
969 void
vm_page_sunbusy(vm_page_t m)970 vm_page_sunbusy(vm_page_t m)
971 {
972 u_int x;
973
974 vm_page_assert_sbusied(m);
975
976 x = vm_page_busy_fetch(m);
977 for (;;) {
978 KASSERT(x != VPB_FREED,
979 ("vm_page_sunbusy: Unlocking freed page."));
980 if (VPB_SHARERS(x) > 1) {
981 if (atomic_fcmpset_int(&m->busy_lock, &x,
982 x - VPB_ONE_SHARER))
983 break;
984 continue;
985 }
986 KASSERT((x & ~VPB_BIT_WAITERS) == VPB_SHARERS_WORD(1),
987 ("vm_page_sunbusy: invalid lock state"));
988 if (!atomic_fcmpset_rel_int(&m->busy_lock, &x, VPB_UNBUSIED))
989 continue;
990 if ((x & VPB_BIT_WAITERS) == 0)
991 break;
992 wakeup(m);
993 break;
994 }
995 }
996
997 /*
998 * vm_page_busy_sleep:
999 *
1000 * Sleep if the page is busy, using the page pointer as wchan.
1001 * This is used to implement the hard-path of the busying mechanism.
1002 *
1003 * If VM_ALLOC_IGN_SBUSY is specified in allocflags, the function
1004 * will not sleep if the page is shared-busy.
1005 *
1006 * The object lock must be held on entry.
1007 *
1008 * Returns true if it slept and dropped the object lock, or false
1009 * if there was no sleep and the lock is still held.
1010 */
1011 bool
vm_page_busy_sleep(vm_page_t m,const char * wmesg,int allocflags)1012 vm_page_busy_sleep(vm_page_t m, const char *wmesg, int allocflags)
1013 {
1014 vm_object_t obj;
1015
1016 obj = m->object;
1017 VM_OBJECT_ASSERT_LOCKED(obj);
1018
1019 return (_vm_page_busy_sleep(obj, m, m->pindex, wmesg, allocflags,
1020 true));
1021 }
1022
1023 /*
1024 * vm_page_busy_sleep_unlocked:
1025 *
1026 * Sleep if the page is busy, using the page pointer as wchan.
1027 * This is used to implement the hard-path of busying mechanism.
1028 *
1029 * If VM_ALLOC_IGN_SBUSY is specified in allocflags, the function
1030 * will not sleep if the page is shared-busy.
1031 *
1032 * The object lock must not be held on entry. The operation will
1033 * return if the page changes identity.
1034 */
1035 void
vm_page_busy_sleep_unlocked(vm_object_t obj,vm_page_t m,vm_pindex_t pindex,const char * wmesg,int allocflags)1036 vm_page_busy_sleep_unlocked(vm_object_t obj, vm_page_t m, vm_pindex_t pindex,
1037 const char *wmesg, int allocflags)
1038 {
1039 VM_OBJECT_ASSERT_UNLOCKED(obj);
1040
1041 (void)_vm_page_busy_sleep(obj, m, pindex, wmesg, allocflags, false);
1042 }
1043
1044 /*
1045 * _vm_page_busy_sleep:
1046 *
1047 * Internal busy sleep function. Verifies the page identity and
1048 * lockstate against parameters. Returns true if it sleeps and
1049 * false otherwise.
1050 *
1051 * allocflags uses VM_ALLOC_* flags to specify the lock required.
1052 *
1053 * If locked is true the lock will be dropped for any true returns
1054 * and held for any false returns.
1055 */
1056 static bool
_vm_page_busy_sleep(vm_object_t obj,vm_page_t m,vm_pindex_t pindex,const char * wmesg,int allocflags,bool locked)1057 _vm_page_busy_sleep(vm_object_t obj, vm_page_t m, vm_pindex_t pindex,
1058 const char *wmesg, int allocflags, bool locked)
1059 {
1060 bool xsleep;
1061 u_int x;
1062
1063 /*
1064 * If the object is busy we must wait for that to drain to zero
1065 * before trying the page again.
1066 */
1067 if (obj != NULL && vm_object_busied(obj)) {
1068 if (locked)
1069 VM_OBJECT_DROP(obj);
1070 vm_object_busy_wait(obj, wmesg);
1071 return (true);
1072 }
1073
1074 if (!vm_page_busied(m))
1075 return (false);
1076
1077 xsleep = (allocflags & (VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY)) != 0;
1078 sleepq_lock(m);
1079 x = vm_page_busy_fetch(m);
1080 do {
1081 /*
1082 * If the page changes objects or becomes unlocked we can
1083 * simply return.
1084 */
1085 if (x == VPB_UNBUSIED ||
1086 (xsleep && (x & VPB_BIT_SHARED) != 0) ||
1087 m->object != obj || m->pindex != pindex) {
1088 sleepq_release(m);
1089 return (false);
1090 }
1091 if ((x & VPB_BIT_WAITERS) != 0)
1092 break;
1093 } while (!atomic_fcmpset_int(&m->busy_lock, &x, x | VPB_BIT_WAITERS));
1094 if (locked)
1095 VM_OBJECT_DROP(obj);
1096 DROP_GIANT();
1097 sleepq_add(m, NULL, wmesg, 0, 0);
1098 sleepq_wait(m, PVM);
1099 PICKUP_GIANT();
1100 return (true);
1101 }
1102
1103 /*
1104 * vm_page_trysbusy:
1105 *
1106 * Try to shared busy a page.
1107 * If the operation succeeds 1 is returned otherwise 0.
1108 * The operation never sleeps.
1109 */
1110 int
vm_page_trysbusy(vm_page_t m)1111 vm_page_trysbusy(vm_page_t m)
1112 {
1113 vm_object_t obj;
1114 u_int x;
1115
1116 obj = m->object;
1117 x = vm_page_busy_fetch(m);
1118 for (;;) {
1119 if ((x & VPB_BIT_SHARED) == 0)
1120 return (0);
1121 /*
1122 * Reduce the window for transient busies that will trigger
1123 * false negatives in vm_page_ps_test().
1124 */
1125 if (obj != NULL && vm_object_busied(obj))
1126 return (0);
1127 if (atomic_fcmpset_acq_int(&m->busy_lock, &x,
1128 x + VPB_ONE_SHARER))
1129 break;
1130 }
1131
1132 /* Refetch the object now that we're guaranteed that it is stable. */
1133 obj = m->object;
1134 if (obj != NULL && vm_object_busied(obj)) {
1135 vm_page_sunbusy(m);
1136 return (0);
1137 }
1138 return (1);
1139 }
1140
1141 /*
1142 * vm_page_tryxbusy:
1143 *
1144 * Try to exclusive busy a page.
1145 * If the operation succeeds 1 is returned otherwise 0.
1146 * The operation never sleeps.
1147 */
1148 int
vm_page_tryxbusy(vm_page_t m)1149 vm_page_tryxbusy(vm_page_t m)
1150 {
1151 vm_object_t obj;
1152
1153 if (atomic_cmpset_acq_int(&m->busy_lock, VPB_UNBUSIED,
1154 VPB_CURTHREAD_EXCLUSIVE) == 0)
1155 return (0);
1156
1157 obj = m->object;
1158 if (obj != NULL && vm_object_busied(obj)) {
1159 vm_page_xunbusy(m);
1160 return (0);
1161 }
1162 return (1);
1163 }
1164
1165 static void
vm_page_xunbusy_hard_tail(vm_page_t m)1166 vm_page_xunbusy_hard_tail(vm_page_t m)
1167 {
1168 atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED);
1169 /* Wake the waiter. */
1170 wakeup(m);
1171 }
1172
1173 /*
1174 * vm_page_xunbusy_hard:
1175 *
1176 * Called when unbusy has failed because there is a waiter.
1177 */
1178 void
vm_page_xunbusy_hard(vm_page_t m)1179 vm_page_xunbusy_hard(vm_page_t m)
1180 {
1181 vm_page_assert_xbusied(m);
1182 vm_page_xunbusy_hard_tail(m);
1183 }
1184
1185 void
vm_page_xunbusy_hard_unchecked(vm_page_t m)1186 vm_page_xunbusy_hard_unchecked(vm_page_t m)
1187 {
1188 vm_page_assert_xbusied_unchecked(m);
1189 vm_page_xunbusy_hard_tail(m);
1190 }
1191
1192 static void
vm_page_busy_free(vm_page_t m)1193 vm_page_busy_free(vm_page_t m)
1194 {
1195 u_int x;
1196
1197 atomic_thread_fence_rel();
1198 x = atomic_swap_int(&m->busy_lock, VPB_FREED);
1199 if ((x & VPB_BIT_WAITERS) != 0)
1200 wakeup(m);
1201 }
1202
1203 /*
1204 * vm_page_unhold_pages:
1205 *
1206 * Unhold each of the pages that is referenced by the given array.
1207 */
1208 void
vm_page_unhold_pages(vm_page_t * ma,int count)1209 vm_page_unhold_pages(vm_page_t *ma, int count)
1210 {
1211
1212 for (; count != 0; count--) {
1213 vm_page_unwire(*ma, PQ_ACTIVE);
1214 ma++;
1215 }
1216 }
1217
1218 vm_page_t
PHYS_TO_VM_PAGE(vm_paddr_t pa)1219 PHYS_TO_VM_PAGE(vm_paddr_t pa)
1220 {
1221 vm_page_t m;
1222
1223 #ifdef VM_PHYSSEG_SPARSE
1224 m = vm_phys_paddr_to_vm_page(pa);
1225 if (m == NULL)
1226 m = vm_phys_fictitious_to_vm_page(pa);
1227 return (m);
1228 #elif defined(VM_PHYSSEG_DENSE)
1229 long pi;
1230
1231 pi = atop(pa);
1232 if (pi >= first_page && (pi - first_page) < vm_page_array_size) {
1233 m = &vm_page_array[pi - first_page];
1234 return (m);
1235 }
1236 return (vm_phys_fictitious_to_vm_page(pa));
1237 #else
1238 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined."
1239 #endif
1240 }
1241
1242 /*
1243 * vm_page_getfake:
1244 *
1245 * Create a fictitious page with the specified physical address and
1246 * memory attribute. The memory attribute is the only the machine-
1247 * dependent aspect of a fictitious page that must be initialized.
1248 */
1249 vm_page_t
vm_page_getfake(vm_paddr_t paddr,vm_memattr_t memattr)1250 vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr)
1251 {
1252 vm_page_t m;
1253
1254 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO);
1255 vm_page_initfake(m, paddr, memattr);
1256 return (m);
1257 }
1258
1259 void
vm_page_initfake(vm_page_t m,vm_paddr_t paddr,vm_memattr_t memattr)1260 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr)
1261 {
1262
1263 if ((m->flags & PG_FICTITIOUS) != 0) {
1264 /*
1265 * The page's memattr might have changed since the
1266 * previous initialization. Update the pmap to the
1267 * new memattr.
1268 */
1269 goto memattr;
1270 }
1271 m->phys_addr = paddr;
1272 m->a.queue = PQ_NONE;
1273 /* Fictitious pages don't use "segind". */
1274 m->flags = PG_FICTITIOUS;
1275 /* Fictitious pages don't use "order" or "pool". */
1276 m->oflags = VPO_UNMANAGED;
1277 m->busy_lock = VPB_CURTHREAD_EXCLUSIVE;
1278 /* Fictitious pages are unevictable. */
1279 m->ref_count = 1;
1280 pmap_page_init(m);
1281 memattr:
1282 pmap_page_set_memattr(m, memattr);
1283 }
1284
1285 /*
1286 * vm_page_putfake:
1287 *
1288 * Release a fictitious page.
1289 */
1290 void
vm_page_putfake(vm_page_t m)1291 vm_page_putfake(vm_page_t m)
1292 {
1293
1294 KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m));
1295 KASSERT((m->flags & PG_FICTITIOUS) != 0,
1296 ("vm_page_putfake: bad page %p", m));
1297 vm_page_assert_xbusied(m);
1298 vm_page_busy_free(m);
1299 uma_zfree(fakepg_zone, m);
1300 }
1301
1302 /*
1303 * vm_page_updatefake:
1304 *
1305 * Update the given fictitious page to the specified physical address and
1306 * memory attribute.
1307 */
1308 void
vm_page_updatefake(vm_page_t m,vm_paddr_t paddr,vm_memattr_t memattr)1309 vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr)
1310 {
1311
1312 KASSERT((m->flags & PG_FICTITIOUS) != 0,
1313 ("vm_page_updatefake: bad page %p", m));
1314 m->phys_addr = paddr;
1315 pmap_page_set_memattr(m, memattr);
1316 }
1317
1318 /*
1319 * vm_page_free:
1320 *
1321 * Free a page.
1322 */
1323 void
vm_page_free(vm_page_t m)1324 vm_page_free(vm_page_t m)
1325 {
1326
1327 m->flags &= ~PG_ZERO;
1328 vm_page_free_toq(m);
1329 }
1330
1331 /*
1332 * vm_page_free_zero:
1333 *
1334 * Free a page to the zerod-pages queue
1335 */
1336 void
vm_page_free_zero(vm_page_t m)1337 vm_page_free_zero(vm_page_t m)
1338 {
1339
1340 m->flags |= PG_ZERO;
1341 vm_page_free_toq(m);
1342 }
1343
1344 /*
1345 * Unbusy and handle the page queueing for a page from a getpages request that
1346 * was optionally read ahead or behind.
1347 */
1348 void
vm_page_readahead_finish(vm_page_t m)1349 vm_page_readahead_finish(vm_page_t m)
1350 {
1351
1352 /* We shouldn't put invalid pages on queues. */
1353 KASSERT(!vm_page_none_valid(m), ("%s: %p is invalid", __func__, m));
1354
1355 /*
1356 * Since the page is not the actually needed one, whether it should
1357 * be activated or deactivated is not obvious. Empirical results
1358 * have shown that deactivating the page is usually the best choice,
1359 * unless the page is wanted by another thread.
1360 */
1361 if ((vm_page_busy_fetch(m) & VPB_BIT_WAITERS) != 0)
1362 vm_page_activate(m);
1363 else
1364 vm_page_deactivate(m);
1365 vm_page_xunbusy_unchecked(m);
1366 }
1367
1368 /*
1369 * Destroy the identity of an invalid page and free it if possible.
1370 * This is intended to be used when reading a page from backing store fails.
1371 */
1372 void
vm_page_free_invalid(vm_page_t m)1373 vm_page_free_invalid(vm_page_t m)
1374 {
1375
1376 KASSERT(vm_page_none_valid(m), ("page %p is valid", m));
1377 KASSERT(!pmap_page_is_mapped(m), ("page %p is mapped", m));
1378 KASSERT(m->object != NULL, ("page %p has no object", m));
1379 VM_OBJECT_ASSERT_WLOCKED(m->object);
1380
1381 /*
1382 * We may be attempting to free the page as part of the handling for an
1383 * I/O error, in which case the page was xbusied by a different thread.
1384 */
1385 vm_page_xbusy_claim(m);
1386
1387 /*
1388 * If someone has wired this page while the object lock
1389 * was not held, then the thread that unwires is responsible
1390 * for freeing the page. Otherwise just free the page now.
1391 * The wire count of this unmapped page cannot change while
1392 * we have the page xbusy and the page's object wlocked.
1393 */
1394 if (vm_page_remove(m))
1395 vm_page_free(m);
1396 }
1397
1398 /*
1399 * vm_page_dirty_KBI: [ internal use only ]
1400 *
1401 * Set all bits in the page's dirty field.
1402 *
1403 * The object containing the specified page must be locked if the
1404 * call is made from the machine-independent layer.
1405 *
1406 * See vm_page_clear_dirty_mask().
1407 *
1408 * This function should only be called by vm_page_dirty().
1409 */
1410 void
vm_page_dirty_KBI(vm_page_t m)1411 vm_page_dirty_KBI(vm_page_t m)
1412 {
1413
1414 /* Refer to this operation by its public name. */
1415 KASSERT(vm_page_all_valid(m), ("vm_page_dirty: page is invalid!"));
1416 m->dirty = VM_PAGE_BITS_ALL;
1417 }
1418
1419 /*
1420 * Insert the given page into the given object at the given pindex. mpred is
1421 * used for memq linkage. From vm_page_insert, lookup is true, mpred is
1422 * initially NULL, and this procedure looks it up. From vm_page_insert_after,
1423 * lookup is false and mpred is known to the caller to be valid, and may be
1424 * NULL if this will be the page with the lowest pindex.
1425 *
1426 * The procedure is marked __always_inline to suggest to the compiler to
1427 * eliminate the lookup parameter and the associated alternate branch.
1428 */
1429 static __always_inline int
vm_page_insert_lookup(vm_page_t m,vm_object_t object,vm_pindex_t pindex,vm_page_t mpred,bool lookup)1430 vm_page_insert_lookup(vm_page_t m, vm_object_t object, vm_pindex_t pindex,
1431 vm_page_t mpred, bool lookup)
1432 {
1433 int error;
1434
1435 VM_OBJECT_ASSERT_WLOCKED(object);
1436 KASSERT(m->object == NULL,
1437 ("vm_page_insert: page %p already inserted", m));
1438
1439 /*
1440 * Record the object/offset pair in this page.
1441 */
1442 m->object = object;
1443 m->pindex = pindex;
1444 m->ref_count |= VPRC_OBJREF;
1445
1446 /*
1447 * Add this page to the object's radix tree, and look up mpred if
1448 * needed.
1449 */
1450 if (lookup)
1451 error = vm_radix_insert_lookup_lt(&object->rtree, m, &mpred);
1452 else
1453 error = vm_radix_insert(&object->rtree, m);
1454 if (__predict_false(error != 0)) {
1455 m->object = NULL;
1456 m->pindex = 0;
1457 m->ref_count &= ~VPRC_OBJREF;
1458 return (1);
1459 }
1460
1461 /*
1462 * Now link into the object's ordered list of backed pages.
1463 */
1464 vm_page_insert_radixdone(m, object, mpred);
1465 vm_pager_page_inserted(object, m);
1466 return (0);
1467 }
1468
1469 /*
1470 * vm_page_insert: [ internal use only ]
1471 *
1472 * Inserts the given mem entry into the object and object list.
1473 *
1474 * The object must be locked.
1475 */
1476 int
vm_page_insert(vm_page_t m,vm_object_t object,vm_pindex_t pindex)1477 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex)
1478 {
1479 return (vm_page_insert_lookup(m, object, pindex, NULL, true));
1480 }
1481
1482 /*
1483 * vm_page_insert_after:
1484 *
1485 * Inserts the page "m" into the specified object at offset "pindex".
1486 *
1487 * The page "mpred" must immediately precede the offset "pindex" within
1488 * the specified object.
1489 *
1490 * The object must be locked.
1491 */
1492 static int
vm_page_insert_after(vm_page_t m,vm_object_t object,vm_pindex_t pindex,vm_page_t mpred)1493 vm_page_insert_after(vm_page_t m, vm_object_t object, vm_pindex_t pindex,
1494 vm_page_t mpred)
1495 {
1496 return (vm_page_insert_lookup(m, object, pindex, mpred, false));
1497 }
1498
1499 /*
1500 * vm_page_insert_radixdone:
1501 *
1502 * Complete page "m" insertion into the specified object after the
1503 * radix trie hooking.
1504 *
1505 * The page "mpred" must precede the offset "m->pindex" within the
1506 * specified object.
1507 *
1508 * The object must be locked.
1509 */
1510 static void
vm_page_insert_radixdone(vm_page_t m,vm_object_t object,vm_page_t mpred)1511 vm_page_insert_radixdone(vm_page_t m, vm_object_t object, vm_page_t mpred)
1512 {
1513
1514 VM_OBJECT_ASSERT_WLOCKED(object);
1515 KASSERT(object != NULL && m->object == object,
1516 ("vm_page_insert_radixdone: page %p has inconsistent object", m));
1517 KASSERT((m->ref_count & VPRC_OBJREF) != 0,
1518 ("vm_page_insert_radixdone: page %p is missing object ref", m));
1519 if (mpred != NULL) {
1520 KASSERT(mpred->object == object,
1521 ("vm_page_insert_radixdone: object doesn't contain mpred"));
1522 KASSERT(mpred->pindex < m->pindex,
1523 ("vm_page_insert_radixdone: mpred doesn't precede pindex"));
1524 KASSERT(TAILQ_NEXT(mpred, listq) == NULL ||
1525 m->pindex < TAILQ_NEXT(mpred, listq)->pindex,
1526 ("vm_page_insert_radixdone: pindex doesn't precede msucc"));
1527 } else {
1528 KASSERT(TAILQ_EMPTY(&object->memq) ||
1529 m->pindex < TAILQ_FIRST(&object->memq)->pindex,
1530 ("vm_page_insert_radixdone: no mpred but not first page"));
1531 }
1532
1533 if (mpred != NULL)
1534 TAILQ_INSERT_AFTER(&object->memq, mpred, m, listq);
1535 else
1536 TAILQ_INSERT_HEAD(&object->memq, m, listq);
1537
1538 /*
1539 * Show that the object has one more resident page.
1540 */
1541 object->resident_page_count++;
1542
1543 /*
1544 * Hold the vnode until the last page is released.
1545 */
1546 if (object->resident_page_count == 1 && object->type == OBJT_VNODE)
1547 vhold(object->handle);
1548
1549 /*
1550 * Since we are inserting a new and possibly dirty page,
1551 * update the object's generation count.
1552 */
1553 if (pmap_page_is_write_mapped(m))
1554 vm_object_set_writeable_dirty(object);
1555 }
1556
1557 /*
1558 * Do the work to remove a page from its object. The caller is responsible for
1559 * updating the page's fields to reflect this removal.
1560 */
1561 static void
vm_page_object_remove(vm_page_t m)1562 vm_page_object_remove(vm_page_t m)
1563 {
1564 vm_object_t object;
1565 vm_page_t mrem __diagused;
1566
1567 vm_page_assert_xbusied(m);
1568 object = m->object;
1569 VM_OBJECT_ASSERT_WLOCKED(object);
1570 KASSERT((m->ref_count & VPRC_OBJREF) != 0,
1571 ("page %p is missing its object ref", m));
1572
1573 /* Deferred free of swap space. */
1574 if ((m->a.flags & PGA_SWAP_FREE) != 0)
1575 vm_pager_page_unswapped(m);
1576
1577 vm_pager_page_removed(object, m);
1578
1579 m->object = NULL;
1580 mrem = vm_radix_remove(&object->rtree, m->pindex);
1581 KASSERT(mrem == m, ("removed page %p, expected page %p", mrem, m));
1582
1583 /*
1584 * Now remove from the object's list of backed pages.
1585 */
1586 TAILQ_REMOVE(&object->memq, m, listq);
1587
1588 /*
1589 * And show that the object has one fewer resident page.
1590 */
1591 object->resident_page_count--;
1592
1593 /*
1594 * The vnode may now be recycled.
1595 */
1596 if (object->resident_page_count == 0 && object->type == OBJT_VNODE)
1597 vdrop(object->handle);
1598 }
1599
1600 /*
1601 * vm_page_remove:
1602 *
1603 * Removes the specified page from its containing object, but does not
1604 * invalidate any backing storage. Returns true if the object's reference
1605 * was the last reference to the page, and false otherwise.
1606 *
1607 * The object must be locked and the page must be exclusively busied.
1608 * The exclusive busy will be released on return. If this is not the
1609 * final ref and the caller does not hold a wire reference it may not
1610 * continue to access the page.
1611 */
1612 bool
vm_page_remove(vm_page_t m)1613 vm_page_remove(vm_page_t m)
1614 {
1615 bool dropped;
1616
1617 dropped = vm_page_remove_xbusy(m);
1618 vm_page_xunbusy(m);
1619
1620 return (dropped);
1621 }
1622
1623 /*
1624 * vm_page_remove_xbusy
1625 *
1626 * Removes the page but leaves the xbusy held. Returns true if this
1627 * removed the final ref and false otherwise.
1628 */
1629 bool
vm_page_remove_xbusy(vm_page_t m)1630 vm_page_remove_xbusy(vm_page_t m)
1631 {
1632
1633 vm_page_object_remove(m);
1634 return (vm_page_drop(m, VPRC_OBJREF) == VPRC_OBJREF);
1635 }
1636
1637 /*
1638 * vm_page_lookup:
1639 *
1640 * Returns the page associated with the object/offset
1641 * pair specified; if none is found, NULL is returned.
1642 *
1643 * The object must be locked.
1644 */
1645 vm_page_t
vm_page_lookup(vm_object_t object,vm_pindex_t pindex)1646 vm_page_lookup(vm_object_t object, vm_pindex_t pindex)
1647 {
1648
1649 VM_OBJECT_ASSERT_LOCKED(object);
1650 return (vm_radix_lookup(&object->rtree, pindex));
1651 }
1652
1653 /*
1654 * vm_page_lookup_unlocked:
1655 *
1656 * Returns the page associated with the object/offset pair specified;
1657 * if none is found, NULL is returned. The page may be no longer be
1658 * present in the object at the time that this function returns. Only
1659 * useful for opportunistic checks such as inmem().
1660 */
1661 vm_page_t
vm_page_lookup_unlocked(vm_object_t object,vm_pindex_t pindex)1662 vm_page_lookup_unlocked(vm_object_t object, vm_pindex_t pindex)
1663 {
1664
1665 return (vm_radix_lookup_unlocked(&object->rtree, pindex));
1666 }
1667
1668 /*
1669 * vm_page_relookup:
1670 *
1671 * Returns a page that must already have been busied by
1672 * the caller. Used for bogus page replacement.
1673 */
1674 vm_page_t
vm_page_relookup(vm_object_t object,vm_pindex_t pindex)1675 vm_page_relookup(vm_object_t object, vm_pindex_t pindex)
1676 {
1677 vm_page_t m;
1678
1679 m = vm_radix_lookup_unlocked(&object->rtree, pindex);
1680 KASSERT(m != NULL && (vm_page_busied(m) || vm_page_wired(m)) &&
1681 m->object == object && m->pindex == pindex,
1682 ("vm_page_relookup: Invalid page %p", m));
1683 return (m);
1684 }
1685
1686 /*
1687 * This should only be used by lockless functions for releasing transient
1688 * incorrect acquires. The page may have been freed after we acquired a
1689 * busy lock. In this case busy_lock == VPB_FREED and we have nothing
1690 * further to do.
1691 */
1692 static void
vm_page_busy_release(vm_page_t m)1693 vm_page_busy_release(vm_page_t m)
1694 {
1695 u_int x;
1696
1697 x = vm_page_busy_fetch(m);
1698 for (;;) {
1699 if (x == VPB_FREED)
1700 break;
1701 if ((x & VPB_BIT_SHARED) != 0 && VPB_SHARERS(x) > 1) {
1702 if (atomic_fcmpset_int(&m->busy_lock, &x,
1703 x - VPB_ONE_SHARER))
1704 break;
1705 continue;
1706 }
1707 KASSERT((x & VPB_BIT_SHARED) != 0 ||
1708 (x & ~VPB_BIT_WAITERS) == VPB_CURTHREAD_EXCLUSIVE,
1709 ("vm_page_busy_release: %p xbusy not owned.", m));
1710 if (!atomic_fcmpset_rel_int(&m->busy_lock, &x, VPB_UNBUSIED))
1711 continue;
1712 if ((x & VPB_BIT_WAITERS) != 0)
1713 wakeup(m);
1714 break;
1715 }
1716 }
1717
1718 /*
1719 * vm_page_find_least:
1720 *
1721 * Returns the page associated with the object with least pindex
1722 * greater than or equal to the parameter pindex, or NULL.
1723 *
1724 * The object must be locked.
1725 */
1726 vm_page_t
vm_page_find_least(vm_object_t object,vm_pindex_t pindex)1727 vm_page_find_least(vm_object_t object, vm_pindex_t pindex)
1728 {
1729 vm_page_t m;
1730
1731 VM_OBJECT_ASSERT_LOCKED(object);
1732 if ((m = TAILQ_FIRST(&object->memq)) != NULL && m->pindex < pindex)
1733 m = vm_radix_lookup_ge(&object->rtree, pindex);
1734 return (m);
1735 }
1736
1737 /*
1738 * Returns the given page's successor (by pindex) within the object if it is
1739 * resident; if none is found, NULL is returned.
1740 *
1741 * The object must be locked.
1742 */
1743 vm_page_t
vm_page_next(vm_page_t m)1744 vm_page_next(vm_page_t m)
1745 {
1746 vm_page_t next;
1747
1748 VM_OBJECT_ASSERT_LOCKED(m->object);
1749 if ((next = TAILQ_NEXT(m, listq)) != NULL) {
1750 MPASS(next->object == m->object);
1751 if (next->pindex != m->pindex + 1)
1752 next = NULL;
1753 }
1754 return (next);
1755 }
1756
1757 /*
1758 * Returns the given page's predecessor (by pindex) within the object if it is
1759 * resident; if none is found, NULL is returned.
1760 *
1761 * The object must be locked.
1762 */
1763 vm_page_t
vm_page_prev(vm_page_t m)1764 vm_page_prev(vm_page_t m)
1765 {
1766 vm_page_t prev;
1767
1768 VM_OBJECT_ASSERT_LOCKED(m->object);
1769 if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL) {
1770 MPASS(prev->object == m->object);
1771 if (prev->pindex != m->pindex - 1)
1772 prev = NULL;
1773 }
1774 return (prev);
1775 }
1776
1777 /*
1778 * Uses the page mnew as a replacement for an existing page at index
1779 * pindex which must be already present in the object.
1780 *
1781 * Both pages must be exclusively busied on enter. The old page is
1782 * unbusied on exit.
1783 *
1784 * A return value of true means mold is now free. If this is not the
1785 * final ref and the caller does not hold a wire reference it may not
1786 * continue to access the page.
1787 */
1788 static bool
vm_page_replace_hold(vm_page_t mnew,vm_object_t object,vm_pindex_t pindex,vm_page_t mold)1789 vm_page_replace_hold(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex,
1790 vm_page_t mold)
1791 {
1792 vm_page_t mret __diagused;
1793 bool dropped;
1794
1795 VM_OBJECT_ASSERT_WLOCKED(object);
1796 vm_page_assert_xbusied(mold);
1797 KASSERT(mnew->object == NULL && (mnew->ref_count & VPRC_OBJREF) == 0,
1798 ("vm_page_replace: page %p already in object", mnew));
1799
1800 /*
1801 * This function mostly follows vm_page_insert() and
1802 * vm_page_remove() without the radix, object count and vnode
1803 * dance. Double check such functions for more comments.
1804 */
1805
1806 mnew->object = object;
1807 mnew->pindex = pindex;
1808 atomic_set_int(&mnew->ref_count, VPRC_OBJREF);
1809 mret = vm_radix_replace(&object->rtree, mnew);
1810 KASSERT(mret == mold,
1811 ("invalid page replacement, mold=%p, mret=%p", mold, mret));
1812 KASSERT((mold->oflags & VPO_UNMANAGED) ==
1813 (mnew->oflags & VPO_UNMANAGED),
1814 ("vm_page_replace: mismatched VPO_UNMANAGED"));
1815
1816 /* Keep the resident page list in sorted order. */
1817 TAILQ_INSERT_AFTER(&object->memq, mold, mnew, listq);
1818 TAILQ_REMOVE(&object->memq, mold, listq);
1819 mold->object = NULL;
1820
1821 /*
1822 * The object's resident_page_count does not change because we have
1823 * swapped one page for another, but the generation count should
1824 * change if the page is dirty.
1825 */
1826 if (pmap_page_is_write_mapped(mnew))
1827 vm_object_set_writeable_dirty(object);
1828 dropped = vm_page_drop(mold, VPRC_OBJREF) == VPRC_OBJREF;
1829 vm_page_xunbusy(mold);
1830
1831 return (dropped);
1832 }
1833
1834 void
vm_page_replace(vm_page_t mnew,vm_object_t object,vm_pindex_t pindex,vm_page_t mold)1835 vm_page_replace(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex,
1836 vm_page_t mold)
1837 {
1838
1839 vm_page_assert_xbusied(mnew);
1840
1841 if (vm_page_replace_hold(mnew, object, pindex, mold))
1842 vm_page_free(mold);
1843 }
1844
1845 /*
1846 * vm_page_rename:
1847 *
1848 * Move the given memory entry from its
1849 * current object to the specified target object/offset.
1850 *
1851 * Note: swap associated with the page must be invalidated by the move. We
1852 * have to do this for several reasons: (1) we aren't freeing the
1853 * page, (2) we are dirtying the page, (3) the VM system is probably
1854 * moving the page from object A to B, and will then later move
1855 * the backing store from A to B and we can't have a conflict.
1856 *
1857 * Note: we *always* dirty the page. It is necessary both for the
1858 * fact that we moved it, and because we may be invalidating
1859 * swap.
1860 *
1861 * The objects must be locked.
1862 */
1863 int
vm_page_rename(vm_page_t m,vm_object_t new_object,vm_pindex_t new_pindex)1864 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex)
1865 {
1866 vm_page_t mpred;
1867 vm_pindex_t opidx;
1868
1869 VM_OBJECT_ASSERT_WLOCKED(new_object);
1870
1871 KASSERT(m->ref_count != 0, ("vm_page_rename: page %p has no refs", m));
1872
1873 /*
1874 * Create a custom version of vm_page_insert() which does not depend
1875 * by m_prev and can cheat on the implementation aspects of the
1876 * function.
1877 */
1878 opidx = m->pindex;
1879 m->pindex = new_pindex;
1880 if (vm_radix_insert_lookup_lt(&new_object->rtree, m, &mpred) != 0) {
1881 m->pindex = opidx;
1882 return (1);
1883 }
1884
1885 /*
1886 * The operation cannot fail anymore. The removal must happen before
1887 * the listq iterator is tainted.
1888 */
1889 m->pindex = opidx;
1890 vm_page_object_remove(m);
1891
1892 /* Return back to the new pindex to complete vm_page_insert(). */
1893 m->pindex = new_pindex;
1894 m->object = new_object;
1895
1896 vm_page_insert_radixdone(m, new_object, mpred);
1897 vm_page_dirty(m);
1898 vm_pager_page_inserted(new_object, m);
1899 return (0);
1900 }
1901
1902 /*
1903 * vm_page_alloc:
1904 *
1905 * Allocate and return a page that is associated with the specified
1906 * object and offset pair. By default, this page is exclusive busied.
1907 *
1908 * The caller must always specify an allocation class.
1909 *
1910 * allocation classes:
1911 * VM_ALLOC_NORMAL normal process request
1912 * VM_ALLOC_SYSTEM system *really* needs a page
1913 * VM_ALLOC_INTERRUPT interrupt time request
1914 *
1915 * optional allocation flags:
1916 * VM_ALLOC_COUNT(number) the number of additional pages that the caller
1917 * intends to allocate
1918 * VM_ALLOC_NOBUSY do not exclusive busy the page
1919 * VM_ALLOC_NODUMP do not include the page in a kernel core dump
1920 * VM_ALLOC_SBUSY shared busy the allocated page
1921 * VM_ALLOC_WIRED wire the allocated page
1922 * VM_ALLOC_ZERO prefer a zeroed page
1923 */
1924 vm_page_t
vm_page_alloc(vm_object_t object,vm_pindex_t pindex,int req)1925 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req)
1926 {
1927
1928 return (vm_page_alloc_after(object, pindex, req,
1929 vm_radix_lookup_le(&object->rtree, pindex)));
1930 }
1931
1932 vm_page_t
vm_page_alloc_domain(vm_object_t object,vm_pindex_t pindex,int domain,int req)1933 vm_page_alloc_domain(vm_object_t object, vm_pindex_t pindex, int domain,
1934 int req)
1935 {
1936
1937 return (vm_page_alloc_domain_after(object, pindex, domain, req,
1938 vm_radix_lookup_le(&object->rtree, pindex)));
1939 }
1940
1941 /*
1942 * Allocate a page in the specified object with the given page index. To
1943 * optimize insertion of the page into the object, the caller must also specifiy
1944 * the resident page in the object with largest index smaller than the given
1945 * page index, or NULL if no such page exists.
1946 */
1947 vm_page_t
vm_page_alloc_after(vm_object_t object,vm_pindex_t pindex,int req,vm_page_t mpred)1948 vm_page_alloc_after(vm_object_t object, vm_pindex_t pindex,
1949 int req, vm_page_t mpred)
1950 {
1951 struct vm_domainset_iter di;
1952 vm_page_t m;
1953 int domain;
1954
1955 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req);
1956 do {
1957 m = vm_page_alloc_domain_after(object, pindex, domain, req,
1958 mpred);
1959 if (m != NULL)
1960 break;
1961 } while (vm_domainset_iter_page(&di, object, &domain) == 0);
1962
1963 return (m);
1964 }
1965
1966 /*
1967 * Returns true if the number of free pages exceeds the minimum
1968 * for the request class and false otherwise.
1969 */
1970 static int
_vm_domain_allocate(struct vm_domain * vmd,int req_class,int npages)1971 _vm_domain_allocate(struct vm_domain *vmd, int req_class, int npages)
1972 {
1973 u_int limit, old, new;
1974
1975 if (req_class == VM_ALLOC_INTERRUPT)
1976 limit = 0;
1977 else if (req_class == VM_ALLOC_SYSTEM)
1978 limit = vmd->vmd_interrupt_free_min;
1979 else
1980 limit = vmd->vmd_free_reserved;
1981
1982 /*
1983 * Attempt to reserve the pages. Fail if we're below the limit.
1984 */
1985 limit += npages;
1986 old = vmd->vmd_free_count;
1987 do {
1988 if (old < limit)
1989 return (0);
1990 new = old - npages;
1991 } while (atomic_fcmpset_int(&vmd->vmd_free_count, &old, new) == 0);
1992
1993 /* Wake the page daemon if we've crossed the threshold. */
1994 if (vm_paging_needed(vmd, new) && !vm_paging_needed(vmd, old))
1995 pagedaemon_wakeup(vmd->vmd_domain);
1996
1997 /* Only update bitsets on transitions. */
1998 if ((old >= vmd->vmd_free_min && new < vmd->vmd_free_min) ||
1999 (old >= vmd->vmd_free_severe && new < vmd->vmd_free_severe))
2000 vm_domain_set(vmd);
2001
2002 return (1);
2003 }
2004
2005 int
vm_domain_allocate(struct vm_domain * vmd,int req,int npages)2006 vm_domain_allocate(struct vm_domain *vmd, int req, int npages)
2007 {
2008 int req_class;
2009
2010 /*
2011 * The page daemon is allowed to dig deeper into the free page list.
2012 */
2013 req_class = req & VM_ALLOC_CLASS_MASK;
2014 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT)
2015 req_class = VM_ALLOC_SYSTEM;
2016 return (_vm_domain_allocate(vmd, req_class, npages));
2017 }
2018
2019 vm_page_t
vm_page_alloc_domain_after(vm_object_t object,vm_pindex_t pindex,int domain,int req,vm_page_t mpred)2020 vm_page_alloc_domain_after(vm_object_t object, vm_pindex_t pindex, int domain,
2021 int req, vm_page_t mpred)
2022 {
2023 struct vm_domain *vmd;
2024 vm_page_t m;
2025 int flags;
2026
2027 #define VPA_FLAGS (VM_ALLOC_CLASS_MASK | VM_ALLOC_WAITFAIL | \
2028 VM_ALLOC_NOWAIT | VM_ALLOC_NOBUSY | \
2029 VM_ALLOC_SBUSY | VM_ALLOC_WIRED | \
2030 VM_ALLOC_NODUMP | VM_ALLOC_ZERO | VM_ALLOC_COUNT_MASK)
2031 KASSERT((req & ~VPA_FLAGS) == 0,
2032 ("invalid request %#x", req));
2033 KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) !=
2034 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)),
2035 ("invalid request %#x", req));
2036 KASSERT(mpred == NULL || mpred->pindex < pindex,
2037 ("mpred %p doesn't precede pindex 0x%jx", mpred,
2038 (uintmax_t)pindex));
2039 VM_OBJECT_ASSERT_WLOCKED(object);
2040
2041 flags = 0;
2042 m = NULL;
2043 if (!vm_pager_can_alloc_page(object, pindex))
2044 return (NULL);
2045 again:
2046 #if VM_NRESERVLEVEL > 0
2047 /*
2048 * Can we allocate the page from a reservation?
2049 */
2050 if (vm_object_reserv(object) &&
2051 (m = vm_reserv_alloc_page(object, pindex, domain, req, mpred)) !=
2052 NULL) {
2053 goto found;
2054 }
2055 #endif
2056 vmd = VM_DOMAIN(domain);
2057 if (vmd->vmd_pgcache[VM_FREEPOOL_DEFAULT].zone != NULL) {
2058 m = uma_zalloc(vmd->vmd_pgcache[VM_FREEPOOL_DEFAULT].zone,
2059 M_NOWAIT | M_NOVM);
2060 if (m != NULL) {
2061 flags |= PG_PCPU_CACHE;
2062 goto found;
2063 }
2064 }
2065 if (vm_domain_allocate(vmd, req, 1)) {
2066 /*
2067 * If not, allocate it from the free page queues.
2068 */
2069 vm_domain_free_lock(vmd);
2070 m = vm_phys_alloc_pages(domain, VM_FREEPOOL_DEFAULT, 0);
2071 vm_domain_free_unlock(vmd);
2072 if (m == NULL) {
2073 vm_domain_freecnt_inc(vmd, 1);
2074 #if VM_NRESERVLEVEL > 0
2075 if (vm_reserv_reclaim_inactive(domain))
2076 goto again;
2077 #endif
2078 }
2079 }
2080 if (m == NULL) {
2081 /*
2082 * Not allocatable, give up.
2083 */
2084 if (vm_domain_alloc_fail(vmd, object, req))
2085 goto again;
2086 return (NULL);
2087 }
2088
2089 /*
2090 * At this point we had better have found a good page.
2091 */
2092 found:
2093 vm_page_dequeue(m);
2094 vm_page_alloc_check(m);
2095
2096 /*
2097 * Initialize the page. Only the PG_ZERO flag is inherited.
2098 */
2099 flags |= m->flags & PG_ZERO;
2100 if ((req & VM_ALLOC_NODUMP) != 0)
2101 flags |= PG_NODUMP;
2102 m->flags = flags;
2103 m->a.flags = 0;
2104 m->oflags = (object->flags & OBJ_UNMANAGED) != 0 ? VPO_UNMANAGED : 0;
2105 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0)
2106 m->busy_lock = VPB_CURTHREAD_EXCLUSIVE;
2107 else if ((req & VM_ALLOC_SBUSY) != 0)
2108 m->busy_lock = VPB_SHARERS_WORD(1);
2109 else
2110 m->busy_lock = VPB_UNBUSIED;
2111 if (req & VM_ALLOC_WIRED) {
2112 vm_wire_add(1);
2113 m->ref_count = 1;
2114 }
2115 m->a.act_count = 0;
2116
2117 if (vm_page_insert_after(m, object, pindex, mpred)) {
2118 if (req & VM_ALLOC_WIRED) {
2119 vm_wire_sub(1);
2120 m->ref_count = 0;
2121 }
2122 KASSERT(m->object == NULL, ("page %p has object", m));
2123 m->oflags = VPO_UNMANAGED;
2124 m->busy_lock = VPB_UNBUSIED;
2125 /* Don't change PG_ZERO. */
2126 vm_page_free_toq(m);
2127 if (req & VM_ALLOC_WAITFAIL) {
2128 VM_OBJECT_WUNLOCK(object);
2129 vm_radix_wait();
2130 VM_OBJECT_WLOCK(object);
2131 }
2132 return (NULL);
2133 }
2134
2135 /* Ignore device objects; the pager sets "memattr" for them. */
2136 if (object->memattr != VM_MEMATTR_DEFAULT &&
2137 (object->flags & OBJ_FICTITIOUS) == 0)
2138 pmap_page_set_memattr(m, object->memattr);
2139
2140 return (m);
2141 }
2142
2143 /*
2144 * vm_page_alloc_contig:
2145 *
2146 * Allocate a contiguous set of physical pages of the given size "npages"
2147 * from the free lists. All of the physical pages must be at or above
2148 * the given physical address "low" and below the given physical address
2149 * "high". The given value "alignment" determines the alignment of the
2150 * first physical page in the set. If the given value "boundary" is
2151 * non-zero, then the set of physical pages cannot cross any physical
2152 * address boundary that is a multiple of that value. Both "alignment"
2153 * and "boundary" must be a power of two.
2154 *
2155 * If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT,
2156 * then the memory attribute setting for the physical pages is configured
2157 * to the object's memory attribute setting. Otherwise, the memory
2158 * attribute setting for the physical pages is configured to "memattr",
2159 * overriding the object's memory attribute setting. However, if the
2160 * object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the
2161 * memory attribute setting for the physical pages cannot be configured
2162 * to VM_MEMATTR_DEFAULT.
2163 *
2164 * The specified object may not contain fictitious pages.
2165 *
2166 * The caller must always specify an allocation class.
2167 *
2168 * allocation classes:
2169 * VM_ALLOC_NORMAL normal process request
2170 * VM_ALLOC_SYSTEM system *really* needs a page
2171 * VM_ALLOC_INTERRUPT interrupt time request
2172 *
2173 * optional allocation flags:
2174 * VM_ALLOC_NOBUSY do not exclusive busy the page
2175 * VM_ALLOC_NODUMP do not include the page in a kernel core dump
2176 * VM_ALLOC_SBUSY shared busy the allocated page
2177 * VM_ALLOC_WIRED wire the allocated page
2178 * VM_ALLOC_ZERO prefer a zeroed page
2179 */
2180 vm_page_t
vm_page_alloc_contig(vm_object_t object,vm_pindex_t pindex,int req,u_long npages,vm_paddr_t low,vm_paddr_t high,u_long alignment,vm_paddr_t boundary,vm_memattr_t memattr)2181 vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req,
2182 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
2183 vm_paddr_t boundary, vm_memattr_t memattr)
2184 {
2185 struct vm_domainset_iter di;
2186 vm_page_t bounds[2];
2187 vm_page_t m;
2188 int domain;
2189 int start_segind;
2190
2191 start_segind = -1;
2192
2193 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req);
2194 do {
2195 m = vm_page_alloc_contig_domain(object, pindex, domain, req,
2196 npages, low, high, alignment, boundary, memattr);
2197 if (m != NULL)
2198 break;
2199 if (start_segind == -1)
2200 start_segind = vm_phys_lookup_segind(low);
2201 if (vm_phys_find_range(bounds, start_segind, domain,
2202 npages, low, high) == -1) {
2203 vm_domainset_iter_ignore(&di, domain);
2204 }
2205 } while (vm_domainset_iter_page(&di, object, &domain) == 0);
2206
2207 return (m);
2208 }
2209
2210 static vm_page_t
vm_page_find_contig_domain(int domain,int req,u_long npages,vm_paddr_t low,vm_paddr_t high,u_long alignment,vm_paddr_t boundary)2211 vm_page_find_contig_domain(int domain, int req, u_long npages, vm_paddr_t low,
2212 vm_paddr_t high, u_long alignment, vm_paddr_t boundary)
2213 {
2214 struct vm_domain *vmd;
2215 vm_page_t m_ret;
2216
2217 /*
2218 * Can we allocate the pages without the number of free pages falling
2219 * below the lower bound for the allocation class?
2220 */
2221 vmd = VM_DOMAIN(domain);
2222 if (!vm_domain_allocate(vmd, req, npages))
2223 return (NULL);
2224 /*
2225 * Try to allocate the pages from the free page queues.
2226 */
2227 vm_domain_free_lock(vmd);
2228 m_ret = vm_phys_alloc_contig(domain, npages, low, high,
2229 alignment, boundary);
2230 vm_domain_free_unlock(vmd);
2231 if (m_ret != NULL)
2232 return (m_ret);
2233 #if VM_NRESERVLEVEL > 0
2234 /*
2235 * Try to break a reservation to allocate the pages.
2236 */
2237 if ((req & VM_ALLOC_NORECLAIM) == 0) {
2238 m_ret = vm_reserv_reclaim_contig(domain, npages, low,
2239 high, alignment, boundary);
2240 if (m_ret != NULL)
2241 return (m_ret);
2242 }
2243 #endif
2244 vm_domain_freecnt_inc(vmd, npages);
2245 return (NULL);
2246 }
2247
2248 vm_page_t
vm_page_alloc_contig_domain(vm_object_t object,vm_pindex_t pindex,int domain,int req,u_long npages,vm_paddr_t low,vm_paddr_t high,u_long alignment,vm_paddr_t boundary,vm_memattr_t memattr)2249 vm_page_alloc_contig_domain(vm_object_t object, vm_pindex_t pindex, int domain,
2250 int req, u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
2251 vm_paddr_t boundary, vm_memattr_t memattr)
2252 {
2253 vm_page_t m, m_ret, mpred;
2254 u_int busy_lock, flags, oflags;
2255
2256 #define VPAC_FLAGS (VPA_FLAGS | VM_ALLOC_NORECLAIM)
2257 KASSERT((req & ~VPAC_FLAGS) == 0,
2258 ("invalid request %#x", req));
2259 KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) !=
2260 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)),
2261 ("invalid request %#x", req));
2262 KASSERT((req & (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM)) !=
2263 (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM),
2264 ("invalid request %#x", req));
2265 VM_OBJECT_ASSERT_WLOCKED(object);
2266 KASSERT((object->flags & OBJ_FICTITIOUS) == 0,
2267 ("vm_page_alloc_contig: object %p has fictitious pages",
2268 object));
2269 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero"));
2270
2271 mpred = vm_radix_lookup_le(&object->rtree, pindex);
2272 KASSERT(mpred == NULL || mpred->pindex != pindex,
2273 ("vm_page_alloc_contig: pindex already allocated"));
2274 for (;;) {
2275 #if VM_NRESERVLEVEL > 0
2276 /*
2277 * Can we allocate the pages from a reservation?
2278 */
2279 if (vm_object_reserv(object) &&
2280 (m_ret = vm_reserv_alloc_contig(object, pindex, domain, req,
2281 mpred, npages, low, high, alignment, boundary)) != NULL) {
2282 break;
2283 }
2284 #endif
2285 if ((m_ret = vm_page_find_contig_domain(domain, req, npages,
2286 low, high, alignment, boundary)) != NULL)
2287 break;
2288 if (!vm_domain_alloc_fail(VM_DOMAIN(domain), object, req))
2289 return (NULL);
2290 }
2291 for (m = m_ret; m < &m_ret[npages]; m++) {
2292 vm_page_dequeue(m);
2293 vm_page_alloc_check(m);
2294 }
2295
2296 /*
2297 * Initialize the pages. Only the PG_ZERO flag is inherited.
2298 */
2299 flags = PG_ZERO;
2300 if ((req & VM_ALLOC_NODUMP) != 0)
2301 flags |= PG_NODUMP;
2302 oflags = (object->flags & OBJ_UNMANAGED) != 0 ? VPO_UNMANAGED : 0;
2303 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0)
2304 busy_lock = VPB_CURTHREAD_EXCLUSIVE;
2305 else if ((req & VM_ALLOC_SBUSY) != 0)
2306 busy_lock = VPB_SHARERS_WORD(1);
2307 else
2308 busy_lock = VPB_UNBUSIED;
2309 if ((req & VM_ALLOC_WIRED) != 0)
2310 vm_wire_add(npages);
2311 if (object->memattr != VM_MEMATTR_DEFAULT &&
2312 memattr == VM_MEMATTR_DEFAULT)
2313 memattr = object->memattr;
2314 for (m = m_ret; m < &m_ret[npages]; m++) {
2315 m->a.flags = 0;
2316 m->flags = (m->flags | PG_NODUMP) & flags;
2317 m->busy_lock = busy_lock;
2318 if ((req & VM_ALLOC_WIRED) != 0)
2319 m->ref_count = 1;
2320 m->a.act_count = 0;
2321 m->oflags = oflags;
2322 if (vm_page_insert_after(m, object, pindex, mpred)) {
2323 if ((req & VM_ALLOC_WIRED) != 0)
2324 vm_wire_sub(npages);
2325 KASSERT(m->object == NULL,
2326 ("page %p has object", m));
2327 mpred = m;
2328 for (m = m_ret; m < &m_ret[npages]; m++) {
2329 if (m <= mpred &&
2330 (req & VM_ALLOC_WIRED) != 0)
2331 m->ref_count = 0;
2332 m->oflags = VPO_UNMANAGED;
2333 m->busy_lock = VPB_UNBUSIED;
2334 /* Don't change PG_ZERO. */
2335 vm_page_free_toq(m);
2336 }
2337 if (req & VM_ALLOC_WAITFAIL) {
2338 VM_OBJECT_WUNLOCK(object);
2339 vm_radix_wait();
2340 VM_OBJECT_WLOCK(object);
2341 }
2342 return (NULL);
2343 }
2344 mpred = m;
2345 if (memattr != VM_MEMATTR_DEFAULT)
2346 pmap_page_set_memattr(m, memattr);
2347 pindex++;
2348 }
2349 return (m_ret);
2350 }
2351
2352 /*
2353 * Allocate a physical page that is not intended to be inserted into a VM
2354 * object. If the "freelist" parameter is not equal to VM_NFREELIST, then only
2355 * pages from the specified vm_phys freelist will be returned.
2356 */
2357 static __always_inline vm_page_t
_vm_page_alloc_noobj_domain(int domain,const int freelist,int req)2358 _vm_page_alloc_noobj_domain(int domain, const int freelist, int req)
2359 {
2360 struct vm_domain *vmd;
2361 vm_page_t m;
2362 int flags;
2363
2364 #define VPAN_FLAGS (VM_ALLOC_CLASS_MASK | VM_ALLOC_WAITFAIL | \
2365 VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | \
2366 VM_ALLOC_NOBUSY | VM_ALLOC_WIRED | \
2367 VM_ALLOC_NODUMP | VM_ALLOC_ZERO | VM_ALLOC_COUNT_MASK)
2368 KASSERT((req & ~VPAN_FLAGS) == 0,
2369 ("invalid request %#x", req));
2370
2371 flags = (req & VM_ALLOC_NODUMP) != 0 ? PG_NODUMP : 0;
2372 vmd = VM_DOMAIN(domain);
2373 again:
2374 if (freelist == VM_NFREELIST &&
2375 vmd->vmd_pgcache[VM_FREEPOOL_DIRECT].zone != NULL) {
2376 m = uma_zalloc(vmd->vmd_pgcache[VM_FREEPOOL_DIRECT].zone,
2377 M_NOWAIT | M_NOVM);
2378 if (m != NULL) {
2379 flags |= PG_PCPU_CACHE;
2380 goto found;
2381 }
2382 }
2383
2384 if (vm_domain_allocate(vmd, req, 1)) {
2385 vm_domain_free_lock(vmd);
2386 if (freelist == VM_NFREELIST)
2387 m = vm_phys_alloc_pages(domain, VM_FREEPOOL_DIRECT, 0);
2388 else
2389 m = vm_phys_alloc_freelist_pages(domain, freelist,
2390 VM_FREEPOOL_DIRECT, 0);
2391 vm_domain_free_unlock(vmd);
2392 if (m == NULL) {
2393 vm_domain_freecnt_inc(vmd, 1);
2394 #if VM_NRESERVLEVEL > 0
2395 if (freelist == VM_NFREELIST &&
2396 vm_reserv_reclaim_inactive(domain))
2397 goto again;
2398 #endif
2399 }
2400 }
2401 if (m == NULL) {
2402 if (vm_domain_alloc_fail(vmd, NULL, req))
2403 goto again;
2404 return (NULL);
2405 }
2406
2407 found:
2408 vm_page_dequeue(m);
2409 vm_page_alloc_check(m);
2410
2411 /*
2412 * Consumers should not rely on a useful default pindex value.
2413 */
2414 m->pindex = 0xdeadc0dedeadc0de;
2415 m->flags = (m->flags & PG_ZERO) | flags;
2416 m->a.flags = 0;
2417 m->oflags = VPO_UNMANAGED;
2418 m->busy_lock = VPB_UNBUSIED;
2419 if ((req & VM_ALLOC_WIRED) != 0) {
2420 vm_wire_add(1);
2421 m->ref_count = 1;
2422 }
2423
2424 if ((req & VM_ALLOC_ZERO) != 0 && (m->flags & PG_ZERO) == 0)
2425 pmap_zero_page(m);
2426
2427 return (m);
2428 }
2429
2430 vm_page_t
vm_page_alloc_freelist(int freelist,int req)2431 vm_page_alloc_freelist(int freelist, int req)
2432 {
2433 struct vm_domainset_iter di;
2434 vm_page_t m;
2435 int domain;
2436
2437 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req);
2438 do {
2439 m = vm_page_alloc_freelist_domain(domain, freelist, req);
2440 if (m != NULL)
2441 break;
2442 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0);
2443
2444 return (m);
2445 }
2446
2447 vm_page_t
vm_page_alloc_freelist_domain(int domain,int freelist,int req)2448 vm_page_alloc_freelist_domain(int domain, int freelist, int req)
2449 {
2450 KASSERT(freelist >= 0 && freelist < VM_NFREELIST,
2451 ("%s: invalid freelist %d", __func__, freelist));
2452
2453 return (_vm_page_alloc_noobj_domain(domain, freelist, req));
2454 }
2455
2456 vm_page_t
vm_page_alloc_noobj(int req)2457 vm_page_alloc_noobj(int req)
2458 {
2459 struct vm_domainset_iter di;
2460 vm_page_t m;
2461 int domain;
2462
2463 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req);
2464 do {
2465 m = vm_page_alloc_noobj_domain(domain, req);
2466 if (m != NULL)
2467 break;
2468 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0);
2469
2470 return (m);
2471 }
2472
2473 vm_page_t
vm_page_alloc_noobj_domain(int domain,int req)2474 vm_page_alloc_noobj_domain(int domain, int req)
2475 {
2476 return (_vm_page_alloc_noobj_domain(domain, VM_NFREELIST, req));
2477 }
2478
2479 vm_page_t
vm_page_alloc_noobj_contig(int req,u_long npages,vm_paddr_t low,vm_paddr_t high,u_long alignment,vm_paddr_t boundary,vm_memattr_t memattr)2480 vm_page_alloc_noobj_contig(int req, u_long npages, vm_paddr_t low,
2481 vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
2482 vm_memattr_t memattr)
2483 {
2484 struct vm_domainset_iter di;
2485 vm_page_t m;
2486 int domain;
2487
2488 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req);
2489 do {
2490 m = vm_page_alloc_noobj_contig_domain(domain, req, npages, low,
2491 high, alignment, boundary, memattr);
2492 if (m != NULL)
2493 break;
2494 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0);
2495
2496 return (m);
2497 }
2498
2499 vm_page_t
vm_page_alloc_noobj_contig_domain(int domain,int req,u_long npages,vm_paddr_t low,vm_paddr_t high,u_long alignment,vm_paddr_t boundary,vm_memattr_t memattr)2500 vm_page_alloc_noobj_contig_domain(int domain, int req, u_long npages,
2501 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
2502 vm_memattr_t memattr)
2503 {
2504 vm_page_t m, m_ret;
2505 u_int flags;
2506
2507 #define VPANC_FLAGS (VPAN_FLAGS | VM_ALLOC_NORECLAIM)
2508 KASSERT((req & ~VPANC_FLAGS) == 0,
2509 ("invalid request %#x", req));
2510 KASSERT((req & (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM)) !=
2511 (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM),
2512 ("invalid request %#x", req));
2513 KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) !=
2514 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)),
2515 ("invalid request %#x", req));
2516 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero"));
2517
2518 while ((m_ret = vm_page_find_contig_domain(domain, req, npages,
2519 low, high, alignment, boundary)) == NULL) {
2520 if (!vm_domain_alloc_fail(VM_DOMAIN(domain), NULL, req))
2521 return (NULL);
2522 }
2523
2524 /*
2525 * Initialize the pages. Only the PG_ZERO flag is inherited.
2526 */
2527 flags = PG_ZERO;
2528 if ((req & VM_ALLOC_NODUMP) != 0)
2529 flags |= PG_NODUMP;
2530 if ((req & VM_ALLOC_WIRED) != 0)
2531 vm_wire_add(npages);
2532 for (m = m_ret; m < &m_ret[npages]; m++) {
2533 vm_page_dequeue(m);
2534 vm_page_alloc_check(m);
2535
2536 /*
2537 * Consumers should not rely on a useful default pindex value.
2538 */
2539 m->pindex = 0xdeadc0dedeadc0de;
2540 m->a.flags = 0;
2541 m->flags = (m->flags | PG_NODUMP) & flags;
2542 m->busy_lock = VPB_UNBUSIED;
2543 if ((req & VM_ALLOC_WIRED) != 0)
2544 m->ref_count = 1;
2545 m->a.act_count = 0;
2546 m->oflags = VPO_UNMANAGED;
2547
2548 /*
2549 * Zero the page before updating any mappings since the page is
2550 * not yet shared with any devices which might require the
2551 * non-default memory attribute. pmap_page_set_memattr()
2552 * flushes data caches before returning.
2553 */
2554 if ((req & VM_ALLOC_ZERO) != 0 && (m->flags & PG_ZERO) == 0)
2555 pmap_zero_page(m);
2556 if (memattr != VM_MEMATTR_DEFAULT)
2557 pmap_page_set_memattr(m, memattr);
2558 }
2559 return (m_ret);
2560 }
2561
2562 /*
2563 * Check a page that has been freshly dequeued from a freelist.
2564 */
2565 static void
vm_page_alloc_check(vm_page_t m)2566 vm_page_alloc_check(vm_page_t m)
2567 {
2568
2569 KASSERT(m->object == NULL, ("page %p has object", m));
2570 KASSERT(m->a.queue == PQ_NONE &&
2571 (m->a.flags & PGA_QUEUE_STATE_MASK) == 0,
2572 ("page %p has unexpected queue %d, flags %#x",
2573 m, m->a.queue, (m->a.flags & PGA_QUEUE_STATE_MASK)));
2574 KASSERT(m->ref_count == 0, ("page %p has references", m));
2575 KASSERT(vm_page_busy_freed(m), ("page %p is not freed", m));
2576 KASSERT(m->dirty == 0, ("page %p is dirty", m));
2577 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT,
2578 ("page %p has unexpected memattr %d",
2579 m, pmap_page_get_memattr(m)));
2580 KASSERT(vm_page_none_valid(m), ("free page %p is valid", m));
2581 pmap_vm_page_alloc_check(m);
2582 }
2583
2584 static int
vm_page_zone_import(void * arg,void ** store,int cnt,int domain,int flags)2585 vm_page_zone_import(void *arg, void **store, int cnt, int domain, int flags)
2586 {
2587 struct vm_domain *vmd;
2588 struct vm_pgcache *pgcache;
2589 int i;
2590
2591 pgcache = arg;
2592 vmd = VM_DOMAIN(pgcache->domain);
2593
2594 /*
2595 * The page daemon should avoid creating extra memory pressure since its
2596 * main purpose is to replenish the store of free pages.
2597 */
2598 if (vmd->vmd_severeset || curproc == pageproc ||
2599 !_vm_domain_allocate(vmd, VM_ALLOC_NORMAL, cnt))
2600 return (0);
2601 domain = vmd->vmd_domain;
2602 vm_domain_free_lock(vmd);
2603 i = vm_phys_alloc_npages(domain, pgcache->pool, cnt,
2604 (vm_page_t *)store);
2605 vm_domain_free_unlock(vmd);
2606 if (cnt != i)
2607 vm_domain_freecnt_inc(vmd, cnt - i);
2608
2609 return (i);
2610 }
2611
2612 static void
vm_page_zone_release(void * arg,void ** store,int cnt)2613 vm_page_zone_release(void *arg, void **store, int cnt)
2614 {
2615 struct vm_domain *vmd;
2616 struct vm_pgcache *pgcache;
2617 vm_page_t m;
2618 int i;
2619
2620 pgcache = arg;
2621 vmd = VM_DOMAIN(pgcache->domain);
2622 vm_domain_free_lock(vmd);
2623 for (i = 0; i < cnt; i++) {
2624 m = (vm_page_t)store[i];
2625 vm_phys_free_pages(m, 0);
2626 }
2627 vm_domain_free_unlock(vmd);
2628 vm_domain_freecnt_inc(vmd, cnt);
2629 }
2630
2631 #define VPSC_ANY 0 /* No restrictions. */
2632 #define VPSC_NORESERV 1 /* Skip reservations; implies VPSC_NOSUPER. */
2633 #define VPSC_NOSUPER 2 /* Skip superpages. */
2634
2635 /*
2636 * vm_page_scan_contig:
2637 *
2638 * Scan vm_page_array[] between the specified entries "m_start" and
2639 * "m_end" for a run of contiguous physical pages that satisfy the
2640 * specified conditions, and return the lowest page in the run. The
2641 * specified "alignment" determines the alignment of the lowest physical
2642 * page in the run. If the specified "boundary" is non-zero, then the
2643 * run of physical pages cannot span a physical address that is a
2644 * multiple of "boundary".
2645 *
2646 * "m_end" is never dereferenced, so it need not point to a vm_page
2647 * structure within vm_page_array[].
2648 *
2649 * "npages" must be greater than zero. "m_start" and "m_end" must not
2650 * span a hole (or discontiguity) in the physical address space. Both
2651 * "alignment" and "boundary" must be a power of two.
2652 */
2653 static vm_page_t
vm_page_scan_contig(u_long npages,vm_page_t m_start,vm_page_t m_end,u_long alignment,vm_paddr_t boundary,int options)2654 vm_page_scan_contig(u_long npages, vm_page_t m_start, vm_page_t m_end,
2655 u_long alignment, vm_paddr_t boundary, int options)
2656 {
2657 vm_object_t object;
2658 vm_paddr_t pa;
2659 vm_page_t m, m_run;
2660 #if VM_NRESERVLEVEL > 0
2661 int level;
2662 #endif
2663 int m_inc, order, run_ext, run_len;
2664
2665 KASSERT(npages > 0, ("npages is 0"));
2666 KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
2667 KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
2668 m_run = NULL;
2669 run_len = 0;
2670 for (m = m_start; m < m_end && run_len < npages; m += m_inc) {
2671 KASSERT((m->flags & PG_MARKER) == 0,
2672 ("page %p is PG_MARKER", m));
2673 KASSERT((m->flags & PG_FICTITIOUS) == 0 || m->ref_count >= 1,
2674 ("fictitious page %p has invalid ref count", m));
2675
2676 /*
2677 * If the current page would be the start of a run, check its
2678 * physical address against the end, alignment, and boundary
2679 * conditions. If it doesn't satisfy these conditions, either
2680 * terminate the scan or advance to the next page that
2681 * satisfies the failed condition.
2682 */
2683 if (run_len == 0) {
2684 KASSERT(m_run == NULL, ("m_run != NULL"));
2685 if (m + npages > m_end)
2686 break;
2687 pa = VM_PAGE_TO_PHYS(m);
2688 if (!vm_addr_align_ok(pa, alignment)) {
2689 m_inc = atop(roundup2(pa, alignment) - pa);
2690 continue;
2691 }
2692 if (!vm_addr_bound_ok(pa, ptoa(npages), boundary)) {
2693 m_inc = atop(roundup2(pa, boundary) - pa);
2694 continue;
2695 }
2696 } else
2697 KASSERT(m_run != NULL, ("m_run == NULL"));
2698
2699 retry:
2700 m_inc = 1;
2701 if (vm_page_wired(m))
2702 run_ext = 0;
2703 #if VM_NRESERVLEVEL > 0
2704 else if ((level = vm_reserv_level(m)) >= 0 &&
2705 (options & VPSC_NORESERV) != 0) {
2706 run_ext = 0;
2707 /* Advance to the end of the reservation. */
2708 pa = VM_PAGE_TO_PHYS(m);
2709 m_inc = atop(roundup2(pa + 1, vm_reserv_size(level)) -
2710 pa);
2711 }
2712 #endif
2713 else if ((object = atomic_load_ptr(&m->object)) != NULL) {
2714 /*
2715 * The page is considered eligible for relocation if
2716 * and only if it could be laundered or reclaimed by
2717 * the page daemon.
2718 */
2719 VM_OBJECT_RLOCK(object);
2720 if (object != m->object) {
2721 VM_OBJECT_RUNLOCK(object);
2722 goto retry;
2723 }
2724 /* Don't care: PG_NODUMP, PG_ZERO. */
2725 if ((object->flags & OBJ_SWAP) == 0 &&
2726 object->type != OBJT_VNODE) {
2727 run_ext = 0;
2728 #if VM_NRESERVLEVEL > 0
2729 } else if ((options & VPSC_NOSUPER) != 0 &&
2730 (level = vm_reserv_level_iffullpop(m)) >= 0) {
2731 run_ext = 0;
2732 /* Advance to the end of the superpage. */
2733 pa = VM_PAGE_TO_PHYS(m);
2734 m_inc = atop(roundup2(pa + 1,
2735 vm_reserv_size(level)) - pa);
2736 #endif
2737 } else if (object->memattr == VM_MEMATTR_DEFAULT &&
2738 vm_page_queue(m) != PQ_NONE && !vm_page_busied(m)) {
2739 /*
2740 * The page is allocated but eligible for
2741 * relocation. Extend the current run by one
2742 * page.
2743 */
2744 KASSERT(pmap_page_get_memattr(m) ==
2745 VM_MEMATTR_DEFAULT,
2746 ("page %p has an unexpected memattr", m));
2747 KASSERT((m->oflags & (VPO_SWAPINPROG |
2748 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0,
2749 ("page %p has unexpected oflags", m));
2750 /* Don't care: PGA_NOSYNC. */
2751 run_ext = 1;
2752 } else
2753 run_ext = 0;
2754 VM_OBJECT_RUNLOCK(object);
2755 #if VM_NRESERVLEVEL > 0
2756 } else if (level >= 0) {
2757 /*
2758 * The page is reserved but not yet allocated. In
2759 * other words, it is still free. Extend the current
2760 * run by one page.
2761 */
2762 run_ext = 1;
2763 #endif
2764 } else if ((order = m->order) < VM_NFREEORDER) {
2765 /*
2766 * The page is enqueued in the physical memory
2767 * allocator's free page queues. Moreover, it is the
2768 * first page in a power-of-two-sized run of
2769 * contiguous free pages. Add these pages to the end
2770 * of the current run, and jump ahead.
2771 */
2772 run_ext = 1 << order;
2773 m_inc = 1 << order;
2774 } else {
2775 /*
2776 * Skip the page for one of the following reasons: (1)
2777 * It is enqueued in the physical memory allocator's
2778 * free page queues. However, it is not the first
2779 * page in a run of contiguous free pages. (This case
2780 * rarely occurs because the scan is performed in
2781 * ascending order.) (2) It is not reserved, and it is
2782 * transitioning from free to allocated. (Conversely,
2783 * the transition from allocated to free for managed
2784 * pages is blocked by the page busy lock.) (3) It is
2785 * allocated but not contained by an object and not
2786 * wired, e.g., allocated by Xen's balloon driver.
2787 */
2788 run_ext = 0;
2789 }
2790
2791 /*
2792 * Extend or reset the current run of pages.
2793 */
2794 if (run_ext > 0) {
2795 if (run_len == 0)
2796 m_run = m;
2797 run_len += run_ext;
2798 } else {
2799 if (run_len > 0) {
2800 m_run = NULL;
2801 run_len = 0;
2802 }
2803 }
2804 }
2805 if (run_len >= npages)
2806 return (m_run);
2807 return (NULL);
2808 }
2809
2810 /*
2811 * vm_page_reclaim_run:
2812 *
2813 * Try to relocate each of the allocated virtual pages within the
2814 * specified run of physical pages to a new physical address. Free the
2815 * physical pages underlying the relocated virtual pages. A virtual page
2816 * is relocatable if and only if it could be laundered or reclaimed by
2817 * the page daemon. Whenever possible, a virtual page is relocated to a
2818 * physical address above "high".
2819 *
2820 * Returns 0 if every physical page within the run was already free or
2821 * just freed by a successful relocation. Otherwise, returns a non-zero
2822 * value indicating why the last attempt to relocate a virtual page was
2823 * unsuccessful.
2824 *
2825 * "req_class" must be an allocation class.
2826 */
2827 static int
vm_page_reclaim_run(int req_class,int domain,u_long npages,vm_page_t m_run,vm_paddr_t high)2828 vm_page_reclaim_run(int req_class, int domain, u_long npages, vm_page_t m_run,
2829 vm_paddr_t high)
2830 {
2831 struct vm_domain *vmd;
2832 struct spglist free;
2833 vm_object_t object;
2834 vm_paddr_t pa;
2835 vm_page_t m, m_end, m_new;
2836 int error, order, req;
2837
2838 KASSERT((req_class & VM_ALLOC_CLASS_MASK) == req_class,
2839 ("req_class is not an allocation class"));
2840 SLIST_INIT(&free);
2841 error = 0;
2842 m = m_run;
2843 m_end = m_run + npages;
2844 for (; error == 0 && m < m_end; m++) {
2845 KASSERT((m->flags & (PG_FICTITIOUS | PG_MARKER)) == 0,
2846 ("page %p is PG_FICTITIOUS or PG_MARKER", m));
2847
2848 /*
2849 * Racily check for wirings. Races are handled once the object
2850 * lock is held and the page is unmapped.
2851 */
2852 if (vm_page_wired(m))
2853 error = EBUSY;
2854 else if ((object = atomic_load_ptr(&m->object)) != NULL) {
2855 /*
2856 * The page is relocated if and only if it could be
2857 * laundered or reclaimed by the page daemon.
2858 */
2859 VM_OBJECT_WLOCK(object);
2860 /* Don't care: PG_NODUMP, PG_ZERO. */
2861 if (m->object != object ||
2862 ((object->flags & OBJ_SWAP) == 0 &&
2863 object->type != OBJT_VNODE))
2864 error = EINVAL;
2865 else if (object->memattr != VM_MEMATTR_DEFAULT)
2866 error = EINVAL;
2867 else if (vm_page_queue(m) != PQ_NONE &&
2868 vm_page_tryxbusy(m) != 0) {
2869 if (vm_page_wired(m)) {
2870 vm_page_xunbusy(m);
2871 error = EBUSY;
2872 goto unlock;
2873 }
2874 KASSERT(pmap_page_get_memattr(m) ==
2875 VM_MEMATTR_DEFAULT,
2876 ("page %p has an unexpected memattr", m));
2877 KASSERT(m->oflags == 0,
2878 ("page %p has unexpected oflags", m));
2879 /* Don't care: PGA_NOSYNC. */
2880 if (!vm_page_none_valid(m)) {
2881 /*
2882 * First, try to allocate a new page
2883 * that is above "high". Failing
2884 * that, try to allocate a new page
2885 * that is below "m_run". Allocate
2886 * the new page between the end of
2887 * "m_run" and "high" only as a last
2888 * resort.
2889 */
2890 req = req_class;
2891 if ((m->flags & PG_NODUMP) != 0)
2892 req |= VM_ALLOC_NODUMP;
2893 if (trunc_page(high) !=
2894 ~(vm_paddr_t)PAGE_MASK) {
2895 m_new =
2896 vm_page_alloc_noobj_contig(
2897 req, 1, round_page(high),
2898 ~(vm_paddr_t)0, PAGE_SIZE,
2899 0, VM_MEMATTR_DEFAULT);
2900 } else
2901 m_new = NULL;
2902 if (m_new == NULL) {
2903 pa = VM_PAGE_TO_PHYS(m_run);
2904 m_new =
2905 vm_page_alloc_noobj_contig(
2906 req, 1, 0, pa - 1,
2907 PAGE_SIZE, 0,
2908 VM_MEMATTR_DEFAULT);
2909 }
2910 if (m_new == NULL) {
2911 pa += ptoa(npages);
2912 m_new =
2913 vm_page_alloc_noobj_contig(
2914 req, 1, pa, high, PAGE_SIZE,
2915 0, VM_MEMATTR_DEFAULT);
2916 }
2917 if (m_new == NULL) {
2918 vm_page_xunbusy(m);
2919 error = ENOMEM;
2920 goto unlock;
2921 }
2922
2923 /*
2924 * Unmap the page and check for new
2925 * wirings that may have been acquired
2926 * through a pmap lookup.
2927 */
2928 if (object->ref_count != 0 &&
2929 !vm_page_try_remove_all(m)) {
2930 vm_page_xunbusy(m);
2931 vm_page_free(m_new);
2932 error = EBUSY;
2933 goto unlock;
2934 }
2935
2936 /*
2937 * Replace "m" with the new page. For
2938 * vm_page_replace(), "m" must be busy
2939 * and dequeued. Finally, change "m"
2940 * as if vm_page_free() was called.
2941 */
2942 m_new->a.flags = m->a.flags &
2943 ~PGA_QUEUE_STATE_MASK;
2944 KASSERT(m_new->oflags == VPO_UNMANAGED,
2945 ("page %p is managed", m_new));
2946 m_new->oflags = 0;
2947 pmap_copy_page(m, m_new);
2948 m_new->valid = m->valid;
2949 m_new->dirty = m->dirty;
2950 m->flags &= ~PG_ZERO;
2951 vm_page_dequeue(m);
2952 if (vm_page_replace_hold(m_new, object,
2953 m->pindex, m) &&
2954 vm_page_free_prep(m))
2955 SLIST_INSERT_HEAD(&free, m,
2956 plinks.s.ss);
2957
2958 /*
2959 * The new page must be deactivated
2960 * before the object is unlocked.
2961 */
2962 vm_page_deactivate(m_new);
2963 } else {
2964 m->flags &= ~PG_ZERO;
2965 vm_page_dequeue(m);
2966 if (vm_page_free_prep(m))
2967 SLIST_INSERT_HEAD(&free, m,
2968 plinks.s.ss);
2969 KASSERT(m->dirty == 0,
2970 ("page %p is dirty", m));
2971 }
2972 } else
2973 error = EBUSY;
2974 unlock:
2975 VM_OBJECT_WUNLOCK(object);
2976 } else {
2977 MPASS(vm_page_domain(m) == domain);
2978 vmd = VM_DOMAIN(domain);
2979 vm_domain_free_lock(vmd);
2980 order = m->order;
2981 if (order < VM_NFREEORDER) {
2982 /*
2983 * The page is enqueued in the physical memory
2984 * allocator's free page queues. Moreover, it
2985 * is the first page in a power-of-two-sized
2986 * run of contiguous free pages. Jump ahead
2987 * to the last page within that run, and
2988 * continue from there.
2989 */
2990 m += (1 << order) - 1;
2991 }
2992 #if VM_NRESERVLEVEL > 0
2993 else if (vm_reserv_is_page_free(m))
2994 order = 0;
2995 #endif
2996 vm_domain_free_unlock(vmd);
2997 if (order == VM_NFREEORDER)
2998 error = EINVAL;
2999 }
3000 }
3001 if ((m = SLIST_FIRST(&free)) != NULL) {
3002 int cnt;
3003
3004 vmd = VM_DOMAIN(domain);
3005 cnt = 0;
3006 vm_domain_free_lock(vmd);
3007 do {
3008 MPASS(vm_page_domain(m) == domain);
3009 SLIST_REMOVE_HEAD(&free, plinks.s.ss);
3010 vm_phys_free_pages(m, 0);
3011 cnt++;
3012 } while ((m = SLIST_FIRST(&free)) != NULL);
3013 vm_domain_free_unlock(vmd);
3014 vm_domain_freecnt_inc(vmd, cnt);
3015 }
3016 return (error);
3017 }
3018
3019 #define NRUNS 16
3020
3021 #define RUN_INDEX(count, nruns) ((count) % (nruns))
3022
3023 #define MIN_RECLAIM 8
3024
3025 /*
3026 * vm_page_reclaim_contig:
3027 *
3028 * Reclaim allocated, contiguous physical memory satisfying the specified
3029 * conditions by relocating the virtual pages using that physical memory.
3030 * Returns 0 if reclamation is successful, ERANGE if the specified domain
3031 * can't possibly satisfy the reclamation request, or ENOMEM if not
3032 * currently able to reclaim the requested number of pages. Since
3033 * relocation requires the allocation of physical pages, reclamation may
3034 * fail with ENOMEM due to a shortage of free pages. When reclamation
3035 * fails in this manner, callers are expected to perform vm_wait() before
3036 * retrying a failed allocation operation, e.g., vm_page_alloc_contig().
3037 *
3038 * The caller must always specify an allocation class through "req".
3039 *
3040 * allocation classes:
3041 * VM_ALLOC_NORMAL normal process request
3042 * VM_ALLOC_SYSTEM system *really* needs a page
3043 * VM_ALLOC_INTERRUPT interrupt time request
3044 *
3045 * The optional allocation flags are ignored.
3046 *
3047 * "npages" must be greater than zero. Both "alignment" and "boundary"
3048 * must be a power of two.
3049 */
3050 int
vm_page_reclaim_contig_domain_ext(int domain,int req,u_long npages,vm_paddr_t low,vm_paddr_t high,u_long alignment,vm_paddr_t boundary,int desired_runs)3051 vm_page_reclaim_contig_domain_ext(int domain, int req, u_long npages,
3052 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
3053 int desired_runs)
3054 {
3055 struct vm_domain *vmd;
3056 vm_page_t bounds[2], m_run, _m_runs[NRUNS], *m_runs;
3057 u_long count, minalign, reclaimed;
3058 int error, i, min_reclaim, nruns, options, req_class;
3059 int segind, start_segind;
3060 int ret;
3061
3062 KASSERT(npages > 0, ("npages is 0"));
3063 KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
3064 KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
3065
3066 ret = ENOMEM;
3067
3068 /*
3069 * If the caller wants to reclaim multiple runs, try to allocate
3070 * space to store the runs. If that fails, fall back to the old
3071 * behavior of just reclaiming MIN_RECLAIM pages.
3072 */
3073 if (desired_runs > 1)
3074 m_runs = malloc((NRUNS + desired_runs) * sizeof(*m_runs),
3075 M_TEMP, M_NOWAIT);
3076 else
3077 m_runs = NULL;
3078
3079 if (m_runs == NULL) {
3080 m_runs = _m_runs;
3081 nruns = NRUNS;
3082 } else {
3083 nruns = NRUNS + desired_runs - 1;
3084 }
3085 min_reclaim = MAX(desired_runs * npages, MIN_RECLAIM);
3086
3087 /*
3088 * The caller will attempt an allocation after some runs have been
3089 * reclaimed and added to the vm_phys buddy lists. Due to limitations
3090 * of vm_phys_alloc_contig(), round up the requested length to the next
3091 * power of two or maximum chunk size, and ensure that each run is
3092 * suitably aligned.
3093 */
3094 minalign = 1ul << imin(flsl(npages - 1), VM_NFREEORDER - 1);
3095 npages = roundup2(npages, minalign);
3096 if (alignment < ptoa(minalign))
3097 alignment = ptoa(minalign);
3098
3099 /*
3100 * The page daemon is allowed to dig deeper into the free page list.
3101 */
3102 req_class = req & VM_ALLOC_CLASS_MASK;
3103 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT)
3104 req_class = VM_ALLOC_SYSTEM;
3105
3106 start_segind = vm_phys_lookup_segind(low);
3107
3108 /*
3109 * Return if the number of free pages cannot satisfy the requested
3110 * allocation.
3111 */
3112 vmd = VM_DOMAIN(domain);
3113 count = vmd->vmd_free_count;
3114 if (count < npages + vmd->vmd_free_reserved || (count < npages +
3115 vmd->vmd_interrupt_free_min && req_class == VM_ALLOC_SYSTEM) ||
3116 (count < npages && req_class == VM_ALLOC_INTERRUPT))
3117 goto done;
3118
3119 /*
3120 * Scan up to three times, relaxing the restrictions ("options") on
3121 * the reclamation of reservations and superpages each time.
3122 */
3123 for (options = VPSC_NORESERV;;) {
3124 bool phys_range_exists = false;
3125
3126 /*
3127 * Find the highest runs that satisfy the given constraints
3128 * and restrictions, and record them in "m_runs".
3129 */
3130 count = 0;
3131 segind = start_segind;
3132 while ((segind = vm_phys_find_range(bounds, segind, domain,
3133 npages, low, high)) != -1) {
3134 phys_range_exists = true;
3135 while ((m_run = vm_page_scan_contig(npages, bounds[0],
3136 bounds[1], alignment, boundary, options))) {
3137 bounds[0] = m_run + npages;
3138 m_runs[RUN_INDEX(count, nruns)] = m_run;
3139 count++;
3140 }
3141 segind++;
3142 }
3143
3144 if (!phys_range_exists) {
3145 ret = ERANGE;
3146 goto done;
3147 }
3148
3149 /*
3150 * Reclaim the highest runs in LIFO (descending) order until
3151 * the number of reclaimed pages, "reclaimed", is at least
3152 * "min_reclaim". Reset "reclaimed" each time because each
3153 * reclamation is idempotent, and runs will (likely) recur
3154 * from one scan to the next as restrictions are relaxed.
3155 */
3156 reclaimed = 0;
3157 for (i = 0; count > 0 && i < nruns; i++) {
3158 count--;
3159 m_run = m_runs[RUN_INDEX(count, nruns)];
3160 error = vm_page_reclaim_run(req_class, domain, npages,
3161 m_run, high);
3162 if (error == 0) {
3163 reclaimed += npages;
3164 if (reclaimed >= min_reclaim) {
3165 ret = 0;
3166 goto done;
3167 }
3168 }
3169 }
3170
3171 /*
3172 * Either relax the restrictions on the next scan or return if
3173 * the last scan had no restrictions.
3174 */
3175 if (options == VPSC_NORESERV)
3176 options = VPSC_NOSUPER;
3177 else if (options == VPSC_NOSUPER)
3178 options = VPSC_ANY;
3179 else if (options == VPSC_ANY) {
3180 if (reclaimed != 0)
3181 ret = 0;
3182 goto done;
3183 }
3184 }
3185 done:
3186 if (m_runs != _m_runs)
3187 free(m_runs, M_TEMP);
3188 return (ret);
3189 }
3190
3191 int
vm_page_reclaim_contig_domain(int domain,int req,u_long npages,vm_paddr_t low,vm_paddr_t high,u_long alignment,vm_paddr_t boundary)3192 vm_page_reclaim_contig_domain(int domain, int req, u_long npages,
3193 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary)
3194 {
3195 return (vm_page_reclaim_contig_domain_ext(domain, req, npages, low, high,
3196 alignment, boundary, 1));
3197 }
3198
3199 int
vm_page_reclaim_contig(int req,u_long npages,vm_paddr_t low,vm_paddr_t high,u_long alignment,vm_paddr_t boundary)3200 vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, vm_paddr_t high,
3201 u_long alignment, vm_paddr_t boundary)
3202 {
3203 struct vm_domainset_iter di;
3204 int domain, ret, status;
3205
3206 ret = ERANGE;
3207
3208 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req);
3209 do {
3210 status = vm_page_reclaim_contig_domain(domain, req, npages, low,
3211 high, alignment, boundary);
3212 if (status == 0)
3213 return (0);
3214 else if (status == ERANGE)
3215 vm_domainset_iter_ignore(&di, domain);
3216 else {
3217 KASSERT(status == ENOMEM, ("Unrecognized error %d "
3218 "from vm_page_reclaim_contig_domain()", status));
3219 ret = ENOMEM;
3220 }
3221 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0);
3222
3223 return (ret);
3224 }
3225
3226 /*
3227 * Set the domain in the appropriate page level domainset.
3228 */
3229 void
vm_domain_set(struct vm_domain * vmd)3230 vm_domain_set(struct vm_domain *vmd)
3231 {
3232
3233 mtx_lock(&vm_domainset_lock);
3234 if (!vmd->vmd_minset && vm_paging_min(vmd)) {
3235 vmd->vmd_minset = 1;
3236 DOMAINSET_SET(vmd->vmd_domain, &vm_min_domains);
3237 }
3238 if (!vmd->vmd_severeset && vm_paging_severe(vmd)) {
3239 vmd->vmd_severeset = 1;
3240 DOMAINSET_SET(vmd->vmd_domain, &vm_severe_domains);
3241 }
3242 mtx_unlock(&vm_domainset_lock);
3243 }
3244
3245 /*
3246 * Clear the domain from the appropriate page level domainset.
3247 */
3248 void
vm_domain_clear(struct vm_domain * vmd)3249 vm_domain_clear(struct vm_domain *vmd)
3250 {
3251
3252 mtx_lock(&vm_domainset_lock);
3253 if (vmd->vmd_minset && !vm_paging_min(vmd)) {
3254 vmd->vmd_minset = 0;
3255 DOMAINSET_CLR(vmd->vmd_domain, &vm_min_domains);
3256 if (vm_min_waiters != 0) {
3257 vm_min_waiters = 0;
3258 wakeup(&vm_min_domains);
3259 }
3260 }
3261 if (vmd->vmd_severeset && !vm_paging_severe(vmd)) {
3262 vmd->vmd_severeset = 0;
3263 DOMAINSET_CLR(vmd->vmd_domain, &vm_severe_domains);
3264 if (vm_severe_waiters != 0) {
3265 vm_severe_waiters = 0;
3266 wakeup(&vm_severe_domains);
3267 }
3268 }
3269
3270 /*
3271 * If pageout daemon needs pages, then tell it that there are
3272 * some free.
3273 */
3274 if (vmd->vmd_pageout_pages_needed &&
3275 vmd->vmd_free_count >= vmd->vmd_pageout_free_min) {
3276 wakeup(&vmd->vmd_pageout_pages_needed);
3277 vmd->vmd_pageout_pages_needed = 0;
3278 }
3279
3280 /* See comments in vm_wait_doms(). */
3281 if (vm_pageproc_waiters) {
3282 vm_pageproc_waiters = 0;
3283 wakeup(&vm_pageproc_waiters);
3284 }
3285 mtx_unlock(&vm_domainset_lock);
3286 }
3287
3288 /*
3289 * Wait for free pages to exceed the min threshold globally.
3290 */
3291 void
vm_wait_min(void)3292 vm_wait_min(void)
3293 {
3294
3295 mtx_lock(&vm_domainset_lock);
3296 while (vm_page_count_min()) {
3297 vm_min_waiters++;
3298 msleep(&vm_min_domains, &vm_domainset_lock, PVM, "vmwait", 0);
3299 }
3300 mtx_unlock(&vm_domainset_lock);
3301 }
3302
3303 /*
3304 * Wait for free pages to exceed the severe threshold globally.
3305 */
3306 void
vm_wait_severe(void)3307 vm_wait_severe(void)
3308 {
3309
3310 mtx_lock(&vm_domainset_lock);
3311 while (vm_page_count_severe()) {
3312 vm_severe_waiters++;
3313 msleep(&vm_severe_domains, &vm_domainset_lock, PVM,
3314 "vmwait", 0);
3315 }
3316 mtx_unlock(&vm_domainset_lock);
3317 }
3318
3319 u_int
vm_wait_count(void)3320 vm_wait_count(void)
3321 {
3322
3323 return (vm_severe_waiters + vm_min_waiters + vm_pageproc_waiters);
3324 }
3325
3326 int
vm_wait_doms(const domainset_t * wdoms,int mflags)3327 vm_wait_doms(const domainset_t *wdoms, int mflags)
3328 {
3329 int error;
3330
3331 error = 0;
3332
3333 /*
3334 * We use racey wakeup synchronization to avoid expensive global
3335 * locking for the pageproc when sleeping with a non-specific vm_wait.
3336 * To handle this, we only sleep for one tick in this instance. It
3337 * is expected that most allocations for the pageproc will come from
3338 * kmem or vm_page_grab* which will use the more specific and
3339 * race-free vm_wait_domain().
3340 */
3341 if (curproc == pageproc) {
3342 mtx_lock(&vm_domainset_lock);
3343 vm_pageproc_waiters++;
3344 error = msleep(&vm_pageproc_waiters, &vm_domainset_lock,
3345 PVM | PDROP | mflags, "pageprocwait", 1);
3346 } else {
3347 /*
3348 * XXX Ideally we would wait only until the allocation could
3349 * be satisfied. This condition can cause new allocators to
3350 * consume all freed pages while old allocators wait.
3351 */
3352 mtx_lock(&vm_domainset_lock);
3353 if (vm_page_count_min_set(wdoms)) {
3354 if (pageproc == NULL)
3355 panic("vm_wait in early boot");
3356 vm_min_waiters++;
3357 error = msleep(&vm_min_domains, &vm_domainset_lock,
3358 PVM | PDROP | mflags, "vmwait", 0);
3359 } else
3360 mtx_unlock(&vm_domainset_lock);
3361 }
3362 return (error);
3363 }
3364
3365 /*
3366 * vm_wait_domain:
3367 *
3368 * Sleep until free pages are available for allocation.
3369 * - Called in various places after failed memory allocations.
3370 */
3371 void
vm_wait_domain(int domain)3372 vm_wait_domain(int domain)
3373 {
3374 struct vm_domain *vmd;
3375 domainset_t wdom;
3376
3377 vmd = VM_DOMAIN(domain);
3378 vm_domain_free_assert_unlocked(vmd);
3379
3380 if (curproc == pageproc) {
3381 mtx_lock(&vm_domainset_lock);
3382 if (vmd->vmd_free_count < vmd->vmd_pageout_free_min) {
3383 vmd->vmd_pageout_pages_needed = 1;
3384 msleep(&vmd->vmd_pageout_pages_needed,
3385 &vm_domainset_lock, PDROP | PSWP, "VMWait", 0);
3386 } else
3387 mtx_unlock(&vm_domainset_lock);
3388 } else {
3389 DOMAINSET_ZERO(&wdom);
3390 DOMAINSET_SET(vmd->vmd_domain, &wdom);
3391 vm_wait_doms(&wdom, 0);
3392 }
3393 }
3394
3395 static int
vm_wait_flags(vm_object_t obj,int mflags)3396 vm_wait_flags(vm_object_t obj, int mflags)
3397 {
3398 struct domainset *d;
3399
3400 d = NULL;
3401
3402 /*
3403 * Carefully fetch pointers only once: the struct domainset
3404 * itself is ummutable but the pointer might change.
3405 */
3406 if (obj != NULL)
3407 d = obj->domain.dr_policy;
3408 if (d == NULL)
3409 d = curthread->td_domain.dr_policy;
3410
3411 return (vm_wait_doms(&d->ds_mask, mflags));
3412 }
3413
3414 /*
3415 * vm_wait:
3416 *
3417 * Sleep until free pages are available for allocation in the
3418 * affinity domains of the obj. If obj is NULL, the domain set
3419 * for the calling thread is used.
3420 * Called in various places after failed memory allocations.
3421 */
3422 void
vm_wait(vm_object_t obj)3423 vm_wait(vm_object_t obj)
3424 {
3425 (void)vm_wait_flags(obj, 0);
3426 }
3427
3428 int
vm_wait_intr(vm_object_t obj)3429 vm_wait_intr(vm_object_t obj)
3430 {
3431 return (vm_wait_flags(obj, PCATCH));
3432 }
3433
3434 /*
3435 * vm_domain_alloc_fail:
3436 *
3437 * Called when a page allocation function fails. Informs the
3438 * pagedaemon and performs the requested wait. Requires the
3439 * domain_free and object lock on entry. Returns with the
3440 * object lock held and free lock released. Returns an error when
3441 * retry is necessary.
3442 *
3443 */
3444 static int
vm_domain_alloc_fail(struct vm_domain * vmd,vm_object_t object,int req)3445 vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, int req)
3446 {
3447
3448 vm_domain_free_assert_unlocked(vmd);
3449
3450 atomic_add_int(&vmd->vmd_pageout_deficit,
3451 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1));
3452 if (req & (VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL)) {
3453 if (object != NULL)
3454 VM_OBJECT_WUNLOCK(object);
3455 vm_wait_domain(vmd->vmd_domain);
3456 if (object != NULL)
3457 VM_OBJECT_WLOCK(object);
3458 if (req & VM_ALLOC_WAITOK)
3459 return (EAGAIN);
3460 }
3461
3462 return (0);
3463 }
3464
3465 /*
3466 * vm_waitpfault:
3467 *
3468 * Sleep until free pages are available for allocation.
3469 * - Called only in vm_fault so that processes page faulting
3470 * can be easily tracked.
3471 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing
3472 * processes will be able to grab memory first. Do not change
3473 * this balance without careful testing first.
3474 */
3475 void
vm_waitpfault(struct domainset * dset,int timo)3476 vm_waitpfault(struct domainset *dset, int timo)
3477 {
3478
3479 /*
3480 * XXX Ideally we would wait only until the allocation could
3481 * be satisfied. This condition can cause new allocators to
3482 * consume all freed pages while old allocators wait.
3483 */
3484 mtx_lock(&vm_domainset_lock);
3485 if (vm_page_count_min_set(&dset->ds_mask)) {
3486 vm_min_waiters++;
3487 msleep(&vm_min_domains, &vm_domainset_lock, PUSER | PDROP,
3488 "pfault", timo);
3489 } else
3490 mtx_unlock(&vm_domainset_lock);
3491 }
3492
3493 static struct vm_pagequeue *
_vm_page_pagequeue(vm_page_t m,uint8_t queue)3494 _vm_page_pagequeue(vm_page_t m, uint8_t queue)
3495 {
3496
3497 return (&vm_pagequeue_domain(m)->vmd_pagequeues[queue]);
3498 }
3499
3500 #ifdef INVARIANTS
3501 static struct vm_pagequeue *
vm_page_pagequeue(vm_page_t m)3502 vm_page_pagequeue(vm_page_t m)
3503 {
3504
3505 return (_vm_page_pagequeue(m, vm_page_astate_load(m).queue));
3506 }
3507 #endif
3508
3509 static __always_inline bool
vm_page_pqstate_fcmpset(vm_page_t m,vm_page_astate_t * old,vm_page_astate_t new)3510 vm_page_pqstate_fcmpset(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new)
3511 {
3512 vm_page_astate_t tmp;
3513
3514 tmp = *old;
3515 do {
3516 if (__predict_true(vm_page_astate_fcmpset(m, old, new)))
3517 return (true);
3518 counter_u64_add(pqstate_commit_retries, 1);
3519 } while (old->_bits == tmp._bits);
3520
3521 return (false);
3522 }
3523
3524 /*
3525 * Do the work of committing a queue state update that moves the page out of
3526 * its current queue.
3527 */
3528 static bool
_vm_page_pqstate_commit_dequeue(struct vm_pagequeue * pq,vm_page_t m,vm_page_astate_t * old,vm_page_astate_t new)3529 _vm_page_pqstate_commit_dequeue(struct vm_pagequeue *pq, vm_page_t m,
3530 vm_page_astate_t *old, vm_page_astate_t new)
3531 {
3532 vm_page_t next;
3533
3534 vm_pagequeue_assert_locked(pq);
3535 KASSERT(vm_page_pagequeue(m) == pq,
3536 ("%s: queue %p does not match page %p", __func__, pq, m));
3537 KASSERT(old->queue != PQ_NONE && new.queue != old->queue,
3538 ("%s: invalid queue indices %d %d",
3539 __func__, old->queue, new.queue));
3540
3541 /*
3542 * Once the queue index of the page changes there is nothing
3543 * synchronizing with further updates to the page's physical
3544 * queue state. Therefore we must speculatively remove the page
3545 * from the queue now and be prepared to roll back if the queue
3546 * state update fails. If the page is not physically enqueued then
3547 * we just update its queue index.
3548 */
3549 if ((old->flags & PGA_ENQUEUED) != 0) {
3550 new.flags &= ~PGA_ENQUEUED;
3551 next = TAILQ_NEXT(m, plinks.q);
3552 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q);
3553 vm_pagequeue_cnt_dec(pq);
3554 if (!vm_page_pqstate_fcmpset(m, old, new)) {
3555 if (next == NULL)
3556 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q);
3557 else
3558 TAILQ_INSERT_BEFORE(next, m, plinks.q);
3559 vm_pagequeue_cnt_inc(pq);
3560 return (false);
3561 } else {
3562 return (true);
3563 }
3564 } else {
3565 return (vm_page_pqstate_fcmpset(m, old, new));
3566 }
3567 }
3568
3569 static bool
vm_page_pqstate_commit_dequeue(vm_page_t m,vm_page_astate_t * old,vm_page_astate_t new)3570 vm_page_pqstate_commit_dequeue(vm_page_t m, vm_page_astate_t *old,
3571 vm_page_astate_t new)
3572 {
3573 struct vm_pagequeue *pq;
3574 vm_page_astate_t as;
3575 bool ret;
3576
3577 pq = _vm_page_pagequeue(m, old->queue);
3578
3579 /*
3580 * The queue field and PGA_ENQUEUED flag are stable only so long as the
3581 * corresponding page queue lock is held.
3582 */
3583 vm_pagequeue_lock(pq);
3584 as = vm_page_astate_load(m);
3585 if (__predict_false(as._bits != old->_bits)) {
3586 *old = as;
3587 ret = false;
3588 } else {
3589 ret = _vm_page_pqstate_commit_dequeue(pq, m, old, new);
3590 }
3591 vm_pagequeue_unlock(pq);
3592 return (ret);
3593 }
3594
3595 /*
3596 * Commit a queue state update that enqueues or requeues a page.
3597 */
3598 static bool
_vm_page_pqstate_commit_requeue(struct vm_pagequeue * pq,vm_page_t m,vm_page_astate_t * old,vm_page_astate_t new)3599 _vm_page_pqstate_commit_requeue(struct vm_pagequeue *pq, vm_page_t m,
3600 vm_page_astate_t *old, vm_page_astate_t new)
3601 {
3602 struct vm_domain *vmd;
3603
3604 vm_pagequeue_assert_locked(pq);
3605 KASSERT(old->queue != PQ_NONE && new.queue == old->queue,
3606 ("%s: invalid queue indices %d %d",
3607 __func__, old->queue, new.queue));
3608
3609 new.flags |= PGA_ENQUEUED;
3610 if (!vm_page_pqstate_fcmpset(m, old, new))
3611 return (false);
3612
3613 if ((old->flags & PGA_ENQUEUED) != 0)
3614 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q);
3615 else
3616 vm_pagequeue_cnt_inc(pq);
3617
3618 /*
3619 * Give PGA_REQUEUE_HEAD precedence over PGA_REQUEUE. In particular, if
3620 * both flags are set in close succession, only PGA_REQUEUE_HEAD will be
3621 * applied, even if it was set first.
3622 */
3623 if ((old->flags & PGA_REQUEUE_HEAD) != 0) {
3624 vmd = vm_pagequeue_domain(m);
3625 KASSERT(pq == &vmd->vmd_pagequeues[PQ_INACTIVE],
3626 ("%s: invalid page queue for page %p", __func__, m));
3627 TAILQ_INSERT_BEFORE(&vmd->vmd_inacthead, m, plinks.q);
3628 } else {
3629 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q);
3630 }
3631 return (true);
3632 }
3633
3634 /*
3635 * Commit a queue state update that encodes a request for a deferred queue
3636 * operation.
3637 */
3638 static bool
vm_page_pqstate_commit_request(vm_page_t m,vm_page_astate_t * old,vm_page_astate_t new)3639 vm_page_pqstate_commit_request(vm_page_t m, vm_page_astate_t *old,
3640 vm_page_astate_t new)
3641 {
3642
3643 KASSERT(old->queue == new.queue || new.queue != PQ_NONE,
3644 ("%s: invalid state, queue %d flags %x",
3645 __func__, new.queue, new.flags));
3646
3647 if (old->_bits != new._bits &&
3648 !vm_page_pqstate_fcmpset(m, old, new))
3649 return (false);
3650 vm_page_pqbatch_submit(m, new.queue);
3651 return (true);
3652 }
3653
3654 /*
3655 * A generic queue state update function. This handles more cases than the
3656 * specialized functions above.
3657 */
3658 bool
vm_page_pqstate_commit(vm_page_t m,vm_page_astate_t * old,vm_page_astate_t new)3659 vm_page_pqstate_commit(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new)
3660 {
3661
3662 if (old->_bits == new._bits)
3663 return (true);
3664
3665 if (old->queue != PQ_NONE && new.queue != old->queue) {
3666 if (!vm_page_pqstate_commit_dequeue(m, old, new))
3667 return (false);
3668 if (new.queue != PQ_NONE)
3669 vm_page_pqbatch_submit(m, new.queue);
3670 } else {
3671 if (!vm_page_pqstate_fcmpset(m, old, new))
3672 return (false);
3673 if (new.queue != PQ_NONE &&
3674 ((new.flags & ~old->flags) & PGA_QUEUE_OP_MASK) != 0)
3675 vm_page_pqbatch_submit(m, new.queue);
3676 }
3677 return (true);
3678 }
3679
3680 /*
3681 * Apply deferred queue state updates to a page.
3682 */
3683 static inline void
vm_pqbatch_process_page(struct vm_pagequeue * pq,vm_page_t m,uint8_t queue)3684 vm_pqbatch_process_page(struct vm_pagequeue *pq, vm_page_t m, uint8_t queue)
3685 {
3686 vm_page_astate_t new, old;
3687
3688 CRITICAL_ASSERT(curthread);
3689 vm_pagequeue_assert_locked(pq);
3690 KASSERT(queue < PQ_COUNT,
3691 ("%s: invalid queue index %d", __func__, queue));
3692 KASSERT(pq == _vm_page_pagequeue(m, queue),
3693 ("%s: page %p does not belong to queue %p", __func__, m, pq));
3694
3695 for (old = vm_page_astate_load(m);;) {
3696 if (__predict_false(old.queue != queue ||
3697 (old.flags & PGA_QUEUE_OP_MASK) == 0)) {
3698 counter_u64_add(queue_nops, 1);
3699 break;
3700 }
3701 KASSERT((m->oflags & VPO_UNMANAGED) == 0,
3702 ("%s: page %p is unmanaged", __func__, m));
3703
3704 new = old;
3705 if ((old.flags & PGA_DEQUEUE) != 0) {
3706 new.flags &= ~PGA_QUEUE_OP_MASK;
3707 new.queue = PQ_NONE;
3708 if (__predict_true(_vm_page_pqstate_commit_dequeue(pq,
3709 m, &old, new))) {
3710 counter_u64_add(queue_ops, 1);
3711 break;
3712 }
3713 } else {
3714 new.flags &= ~(PGA_REQUEUE | PGA_REQUEUE_HEAD);
3715 if (__predict_true(_vm_page_pqstate_commit_requeue(pq,
3716 m, &old, new))) {
3717 counter_u64_add(queue_ops, 1);
3718 break;
3719 }
3720 }
3721 }
3722 }
3723
3724 static void
vm_pqbatch_process(struct vm_pagequeue * pq,struct vm_batchqueue * bq,uint8_t queue)3725 vm_pqbatch_process(struct vm_pagequeue *pq, struct vm_batchqueue *bq,
3726 uint8_t queue)
3727 {
3728 int i;
3729
3730 for (i = 0; i < bq->bq_cnt; i++)
3731 vm_pqbatch_process_page(pq, bq->bq_pa[i], queue);
3732 vm_batchqueue_init(bq);
3733 }
3734
3735 /*
3736 * vm_page_pqbatch_submit: [ internal use only ]
3737 *
3738 * Enqueue a page in the specified page queue's batched work queue.
3739 * The caller must have encoded the requested operation in the page
3740 * structure's a.flags field.
3741 */
3742 void
vm_page_pqbatch_submit(vm_page_t m,uint8_t queue)3743 vm_page_pqbatch_submit(vm_page_t m, uint8_t queue)
3744 {
3745 struct vm_batchqueue *bq;
3746 struct vm_pagequeue *pq;
3747 int domain, slots_remaining;
3748
3749 KASSERT(queue < PQ_COUNT, ("invalid queue %d", queue));
3750
3751 domain = vm_page_domain(m);
3752 critical_enter();
3753 bq = DPCPU_PTR(pqbatch[domain][queue]);
3754 slots_remaining = vm_batchqueue_insert(bq, m);
3755 if (slots_remaining > (VM_BATCHQUEUE_SIZE >> 1)) {
3756 /* keep building the bq */
3757 critical_exit();
3758 return;
3759 } else if (slots_remaining > 0 ) {
3760 /* Try to process the bq if we can get the lock */
3761 pq = &VM_DOMAIN(domain)->vmd_pagequeues[queue];
3762 if (vm_pagequeue_trylock(pq)) {
3763 vm_pqbatch_process(pq, bq, queue);
3764 vm_pagequeue_unlock(pq);
3765 }
3766 critical_exit();
3767 return;
3768 }
3769 critical_exit();
3770
3771 /* if we make it here, the bq is full so wait for the lock */
3772
3773 pq = &VM_DOMAIN(domain)->vmd_pagequeues[queue];
3774 vm_pagequeue_lock(pq);
3775 critical_enter();
3776 bq = DPCPU_PTR(pqbatch[domain][queue]);
3777 vm_pqbatch_process(pq, bq, queue);
3778 vm_pqbatch_process_page(pq, m, queue);
3779 vm_pagequeue_unlock(pq);
3780 critical_exit();
3781 }
3782
3783 /*
3784 * vm_page_pqbatch_drain: [ internal use only ]
3785 *
3786 * Force all per-CPU page queue batch queues to be drained. This is
3787 * intended for use in severe memory shortages, to ensure that pages
3788 * do not remain stuck in the batch queues.
3789 */
3790 void
vm_page_pqbatch_drain(void)3791 vm_page_pqbatch_drain(void)
3792 {
3793 struct thread *td;
3794 struct vm_domain *vmd;
3795 struct vm_pagequeue *pq;
3796 int cpu, domain, queue;
3797
3798 td = curthread;
3799 CPU_FOREACH(cpu) {
3800 thread_lock(td);
3801 sched_bind(td, cpu);
3802 thread_unlock(td);
3803
3804 for (domain = 0; domain < vm_ndomains; domain++) {
3805 vmd = VM_DOMAIN(domain);
3806 for (queue = 0; queue < PQ_COUNT; queue++) {
3807 pq = &vmd->vmd_pagequeues[queue];
3808 vm_pagequeue_lock(pq);
3809 critical_enter();
3810 vm_pqbatch_process(pq,
3811 DPCPU_PTR(pqbatch[domain][queue]), queue);
3812 critical_exit();
3813 vm_pagequeue_unlock(pq);
3814 }
3815 }
3816 }
3817 thread_lock(td);
3818 sched_unbind(td);
3819 thread_unlock(td);
3820 }
3821
3822 /*
3823 * vm_page_dequeue_deferred: [ internal use only ]
3824 *
3825 * Request removal of the given page from its current page
3826 * queue. Physical removal from the queue may be deferred
3827 * indefinitely.
3828 */
3829 void
vm_page_dequeue_deferred(vm_page_t m)3830 vm_page_dequeue_deferred(vm_page_t m)
3831 {
3832 vm_page_astate_t new, old;
3833
3834 old = vm_page_astate_load(m);
3835 do {
3836 if (old.queue == PQ_NONE) {
3837 KASSERT((old.flags & PGA_QUEUE_STATE_MASK) == 0,
3838 ("%s: page %p has unexpected queue state",
3839 __func__, m));
3840 break;
3841 }
3842 new = old;
3843 new.flags |= PGA_DEQUEUE;
3844 } while (!vm_page_pqstate_commit_request(m, &old, new));
3845 }
3846
3847 /*
3848 * vm_page_dequeue:
3849 *
3850 * Remove the page from whichever page queue it's in, if any, before
3851 * returning.
3852 */
3853 void
vm_page_dequeue(vm_page_t m)3854 vm_page_dequeue(vm_page_t m)
3855 {
3856 vm_page_astate_t new, old;
3857
3858 old = vm_page_astate_load(m);
3859 do {
3860 if (old.queue == PQ_NONE) {
3861 KASSERT((old.flags & PGA_QUEUE_STATE_MASK) == 0,
3862 ("%s: page %p has unexpected queue state",
3863 __func__, m));
3864 break;
3865 }
3866 new = old;
3867 new.flags &= ~PGA_QUEUE_OP_MASK;
3868 new.queue = PQ_NONE;
3869 } while (!vm_page_pqstate_commit_dequeue(m, &old, new));
3870
3871 }
3872
3873 /*
3874 * Schedule the given page for insertion into the specified page queue.
3875 * Physical insertion of the page may be deferred indefinitely.
3876 */
3877 static void
vm_page_enqueue(vm_page_t m,uint8_t queue)3878 vm_page_enqueue(vm_page_t m, uint8_t queue)
3879 {
3880
3881 KASSERT(m->a.queue == PQ_NONE &&
3882 (m->a.flags & PGA_QUEUE_STATE_MASK) == 0,
3883 ("%s: page %p is already enqueued", __func__, m));
3884 KASSERT(m->ref_count > 0,
3885 ("%s: page %p does not carry any references", __func__, m));
3886
3887 m->a.queue = queue;
3888 if ((m->a.flags & PGA_REQUEUE) == 0)
3889 vm_page_aflag_set(m, PGA_REQUEUE);
3890 vm_page_pqbatch_submit(m, queue);
3891 }
3892
3893 /*
3894 * vm_page_free_prep:
3895 *
3896 * Prepares the given page to be put on the free list,
3897 * disassociating it from any VM object. The caller may return
3898 * the page to the free list only if this function returns true.
3899 *
3900 * The object, if it exists, must be locked, and then the page must
3901 * be xbusy. Otherwise the page must be not busied. A managed
3902 * page must be unmapped.
3903 */
3904 static bool
vm_page_free_prep(vm_page_t m)3905 vm_page_free_prep(vm_page_t m)
3906 {
3907
3908 /*
3909 * Synchronize with threads that have dropped a reference to this
3910 * page.
3911 */
3912 atomic_thread_fence_acq();
3913
3914 #if defined(DIAGNOSTIC) && defined(PHYS_TO_DMAP)
3915 if (PMAP_HAS_DMAP && (m->flags & PG_ZERO) != 0) {
3916 uint64_t *p;
3917 int i;
3918 p = (uint64_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m));
3919 for (i = 0; i < PAGE_SIZE / sizeof(uint64_t); i++, p++)
3920 KASSERT(*p == 0, ("vm_page_free_prep %p PG_ZERO %d %jx",
3921 m, i, (uintmax_t)*p));
3922 }
3923 #endif
3924 if ((m->oflags & VPO_UNMANAGED) == 0) {
3925 KASSERT(!pmap_page_is_mapped(m),
3926 ("vm_page_free_prep: freeing mapped page %p", m));
3927 KASSERT((m->a.flags & (PGA_EXECUTABLE | PGA_WRITEABLE)) == 0,
3928 ("vm_page_free_prep: mapping flags set in page %p", m));
3929 } else {
3930 KASSERT(m->a.queue == PQ_NONE,
3931 ("vm_page_free_prep: unmanaged page %p is queued", m));
3932 }
3933 VM_CNT_INC(v_tfree);
3934
3935 if (m->object != NULL) {
3936 KASSERT(((m->oflags & VPO_UNMANAGED) != 0) ==
3937 ((m->object->flags & OBJ_UNMANAGED) != 0),
3938 ("vm_page_free_prep: managed flag mismatch for page %p",
3939 m));
3940 vm_page_assert_xbusied(m);
3941
3942 /*
3943 * The object reference can be released without an atomic
3944 * operation.
3945 */
3946 KASSERT((m->flags & PG_FICTITIOUS) != 0 ||
3947 m->ref_count == VPRC_OBJREF,
3948 ("vm_page_free_prep: page %p has unexpected ref_count %u",
3949 m, m->ref_count));
3950 vm_page_object_remove(m);
3951 m->ref_count -= VPRC_OBJREF;
3952 } else
3953 vm_page_assert_unbusied(m);
3954
3955 vm_page_busy_free(m);
3956
3957 /*
3958 * If fictitious remove object association and
3959 * return.
3960 */
3961 if ((m->flags & PG_FICTITIOUS) != 0) {
3962 KASSERT(m->ref_count == 1,
3963 ("fictitious page %p is referenced", m));
3964 KASSERT(m->a.queue == PQ_NONE,
3965 ("fictitious page %p is queued", m));
3966 return (false);
3967 }
3968
3969 /*
3970 * Pages need not be dequeued before they are returned to the physical
3971 * memory allocator, but they must at least be marked for a deferred
3972 * dequeue.
3973 */
3974 if ((m->oflags & VPO_UNMANAGED) == 0)
3975 vm_page_dequeue_deferred(m);
3976
3977 m->valid = 0;
3978 vm_page_undirty(m);
3979
3980 if (m->ref_count != 0)
3981 panic("vm_page_free_prep: page %p has references", m);
3982
3983 /*
3984 * Restore the default memory attribute to the page.
3985 */
3986 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT)
3987 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT);
3988
3989 #if VM_NRESERVLEVEL > 0
3990 /*
3991 * Determine whether the page belongs to a reservation. If the page was
3992 * allocated from a per-CPU cache, it cannot belong to a reservation, so
3993 * as an optimization, we avoid the check in that case.
3994 */
3995 if ((m->flags & PG_PCPU_CACHE) == 0 && vm_reserv_free_page(m))
3996 return (false);
3997 #endif
3998
3999 return (true);
4000 }
4001
4002 /*
4003 * vm_page_free_toq:
4004 *
4005 * Returns the given page to the free list, disassociating it
4006 * from any VM object.
4007 *
4008 * The object must be locked. The page must be exclusively busied if it
4009 * belongs to an object.
4010 */
4011 static void
vm_page_free_toq(vm_page_t m)4012 vm_page_free_toq(vm_page_t m)
4013 {
4014 struct vm_domain *vmd;
4015 uma_zone_t zone;
4016
4017 if (!vm_page_free_prep(m))
4018 return;
4019
4020 vmd = vm_pagequeue_domain(m);
4021 zone = vmd->vmd_pgcache[m->pool].zone;
4022 if ((m->flags & PG_PCPU_CACHE) != 0 && zone != NULL) {
4023 uma_zfree(zone, m);
4024 return;
4025 }
4026 vm_domain_free_lock(vmd);
4027 vm_phys_free_pages(m, 0);
4028 vm_domain_free_unlock(vmd);
4029 vm_domain_freecnt_inc(vmd, 1);
4030 }
4031
4032 /*
4033 * vm_page_free_pages_toq:
4034 *
4035 * Returns a list of pages to the free list, disassociating it
4036 * from any VM object. In other words, this is equivalent to
4037 * calling vm_page_free_toq() for each page of a list of VM objects.
4038 */
4039 void
vm_page_free_pages_toq(struct spglist * free,bool update_wire_count)4040 vm_page_free_pages_toq(struct spglist *free, bool update_wire_count)
4041 {
4042 vm_page_t m;
4043 int count;
4044
4045 if (SLIST_EMPTY(free))
4046 return;
4047
4048 count = 0;
4049 while ((m = SLIST_FIRST(free)) != NULL) {
4050 count++;
4051 SLIST_REMOVE_HEAD(free, plinks.s.ss);
4052 vm_page_free_toq(m);
4053 }
4054
4055 if (update_wire_count)
4056 vm_wire_sub(count);
4057 }
4058
4059 /*
4060 * Mark this page as wired down. For managed pages, this prevents reclamation
4061 * by the page daemon, or when the containing object, if any, is destroyed.
4062 */
4063 void
vm_page_wire(vm_page_t m)4064 vm_page_wire(vm_page_t m)
4065 {
4066 u_int old;
4067
4068 #ifdef INVARIANTS
4069 if (m->object != NULL && !vm_page_busied(m) &&
4070 !vm_object_busied(m->object))
4071 VM_OBJECT_ASSERT_LOCKED(m->object);
4072 #endif
4073 KASSERT((m->flags & PG_FICTITIOUS) == 0 ||
4074 VPRC_WIRE_COUNT(m->ref_count) >= 1,
4075 ("vm_page_wire: fictitious page %p has zero wirings", m));
4076
4077 old = atomic_fetchadd_int(&m->ref_count, 1);
4078 KASSERT(VPRC_WIRE_COUNT(old) != VPRC_WIRE_COUNT_MAX,
4079 ("vm_page_wire: counter overflow for page %p", m));
4080 if (VPRC_WIRE_COUNT(old) == 0) {
4081 if ((m->oflags & VPO_UNMANAGED) == 0)
4082 vm_page_aflag_set(m, PGA_DEQUEUE);
4083 vm_wire_add(1);
4084 }
4085 }
4086
4087 /*
4088 * Attempt to wire a mapped page following a pmap lookup of that page.
4089 * This may fail if a thread is concurrently tearing down mappings of the page.
4090 * The transient failure is acceptable because it translates to the
4091 * failure of the caller pmap_extract_and_hold(), which should be then
4092 * followed by the vm_fault() fallback, see e.g. vm_fault_quick_hold_pages().
4093 */
4094 bool
vm_page_wire_mapped(vm_page_t m)4095 vm_page_wire_mapped(vm_page_t m)
4096 {
4097 u_int old;
4098
4099 old = m->ref_count;
4100 do {
4101 KASSERT(old > 0,
4102 ("vm_page_wire_mapped: wiring unreferenced page %p", m));
4103 if ((old & VPRC_BLOCKED) != 0)
4104 return (false);
4105 } while (!atomic_fcmpset_int(&m->ref_count, &old, old + 1));
4106
4107 if (VPRC_WIRE_COUNT(old) == 0) {
4108 if ((m->oflags & VPO_UNMANAGED) == 0)
4109 vm_page_aflag_set(m, PGA_DEQUEUE);
4110 vm_wire_add(1);
4111 }
4112 return (true);
4113 }
4114
4115 /*
4116 * Release a wiring reference to a managed page. If the page still belongs to
4117 * an object, update its position in the page queues to reflect the reference.
4118 * If the wiring was the last reference to the page, free the page.
4119 */
4120 static void
vm_page_unwire_managed(vm_page_t m,uint8_t nqueue,bool noreuse)4121 vm_page_unwire_managed(vm_page_t m, uint8_t nqueue, bool noreuse)
4122 {
4123 u_int old;
4124
4125 KASSERT((m->oflags & VPO_UNMANAGED) == 0,
4126 ("%s: page %p is unmanaged", __func__, m));
4127
4128 /*
4129 * Update LRU state before releasing the wiring reference.
4130 * Use a release store when updating the reference count to
4131 * synchronize with vm_page_free_prep().
4132 */
4133 old = m->ref_count;
4134 do {
4135 KASSERT(VPRC_WIRE_COUNT(old) > 0,
4136 ("vm_page_unwire: wire count underflow for page %p", m));
4137
4138 if (old > VPRC_OBJREF + 1) {
4139 /*
4140 * The page has at least one other wiring reference. An
4141 * earlier iteration of this loop may have called
4142 * vm_page_release_toq() and cleared PGA_DEQUEUE, so
4143 * re-set it if necessary.
4144 */
4145 if ((vm_page_astate_load(m).flags & PGA_DEQUEUE) == 0)
4146 vm_page_aflag_set(m, PGA_DEQUEUE);
4147 } else if (old == VPRC_OBJREF + 1) {
4148 /*
4149 * This is the last wiring. Clear PGA_DEQUEUE and
4150 * update the page's queue state to reflect the
4151 * reference. If the page does not belong to an object
4152 * (i.e., the VPRC_OBJREF bit is clear), we only need to
4153 * clear leftover queue state.
4154 */
4155 vm_page_release_toq(m, nqueue, noreuse);
4156 } else if (old == 1) {
4157 vm_page_aflag_clear(m, PGA_DEQUEUE);
4158 }
4159 } while (!atomic_fcmpset_rel_int(&m->ref_count, &old, old - 1));
4160
4161 if (VPRC_WIRE_COUNT(old) == 1) {
4162 vm_wire_sub(1);
4163 if (old == 1)
4164 vm_page_free(m);
4165 }
4166 }
4167
4168 /*
4169 * Release one wiring of the specified page, potentially allowing it to be
4170 * paged out.
4171 *
4172 * Only managed pages belonging to an object can be paged out. If the number
4173 * of wirings transitions to zero and the page is eligible for page out, then
4174 * the page is added to the specified paging queue. If the released wiring
4175 * represented the last reference to the page, the page is freed.
4176 */
4177 void
vm_page_unwire(vm_page_t m,uint8_t nqueue)4178 vm_page_unwire(vm_page_t m, uint8_t nqueue)
4179 {
4180
4181 KASSERT(nqueue < PQ_COUNT,
4182 ("vm_page_unwire: invalid queue %u request for page %p",
4183 nqueue, m));
4184
4185 if ((m->oflags & VPO_UNMANAGED) != 0) {
4186 if (vm_page_unwire_noq(m) && m->ref_count == 0)
4187 vm_page_free(m);
4188 return;
4189 }
4190 vm_page_unwire_managed(m, nqueue, false);
4191 }
4192
4193 /*
4194 * Unwire a page without (re-)inserting it into a page queue. It is up
4195 * to the caller to enqueue, requeue, or free the page as appropriate.
4196 * In most cases involving managed pages, vm_page_unwire() should be used
4197 * instead.
4198 */
4199 bool
vm_page_unwire_noq(vm_page_t m)4200 vm_page_unwire_noq(vm_page_t m)
4201 {
4202 u_int old;
4203
4204 old = vm_page_drop(m, 1);
4205 KASSERT(VPRC_WIRE_COUNT(old) != 0,
4206 ("%s: counter underflow for page %p", __func__, m));
4207 KASSERT((m->flags & PG_FICTITIOUS) == 0 || VPRC_WIRE_COUNT(old) > 1,
4208 ("%s: missing ref on fictitious page %p", __func__, m));
4209
4210 if (VPRC_WIRE_COUNT(old) > 1)
4211 return (false);
4212 if ((m->oflags & VPO_UNMANAGED) == 0)
4213 vm_page_aflag_clear(m, PGA_DEQUEUE);
4214 vm_wire_sub(1);
4215 return (true);
4216 }
4217
4218 /*
4219 * Ensure that the page ends up in the specified page queue. If the page is
4220 * active or being moved to the active queue, ensure that its act_count is
4221 * at least ACT_INIT but do not otherwise mess with it.
4222 */
4223 static __always_inline void
vm_page_mvqueue(vm_page_t m,const uint8_t nqueue,const uint16_t nflag)4224 vm_page_mvqueue(vm_page_t m, const uint8_t nqueue, const uint16_t nflag)
4225 {
4226 vm_page_astate_t old, new;
4227
4228 KASSERT(m->ref_count > 0,
4229 ("%s: page %p does not carry any references", __func__, m));
4230 KASSERT(nflag == PGA_REQUEUE || nflag == PGA_REQUEUE_HEAD,
4231 ("%s: invalid flags %x", __func__, nflag));
4232
4233 if ((m->oflags & VPO_UNMANAGED) != 0 || vm_page_wired(m))
4234 return;
4235
4236 old = vm_page_astate_load(m);
4237 do {
4238 if ((old.flags & PGA_DEQUEUE) != 0)
4239 break;
4240 new = old;
4241 new.flags &= ~PGA_QUEUE_OP_MASK;
4242 if (nqueue == PQ_ACTIVE)
4243 new.act_count = max(old.act_count, ACT_INIT);
4244 if (old.queue == nqueue) {
4245 /*
4246 * There is no need to requeue pages already in the
4247 * active queue.
4248 */
4249 if (nqueue != PQ_ACTIVE ||
4250 (old.flags & PGA_ENQUEUED) == 0)
4251 new.flags |= nflag;
4252 } else {
4253 new.flags |= nflag;
4254 new.queue = nqueue;
4255 }
4256 } while (!vm_page_pqstate_commit(m, &old, new));
4257 }
4258
4259 /*
4260 * Put the specified page on the active list (if appropriate).
4261 */
4262 void
vm_page_activate(vm_page_t m)4263 vm_page_activate(vm_page_t m)
4264 {
4265
4266 vm_page_mvqueue(m, PQ_ACTIVE, PGA_REQUEUE);
4267 }
4268
4269 /*
4270 * Move the specified page to the tail of the inactive queue, or requeue
4271 * the page if it is already in the inactive queue.
4272 */
4273 void
vm_page_deactivate(vm_page_t m)4274 vm_page_deactivate(vm_page_t m)
4275 {
4276
4277 vm_page_mvqueue(m, PQ_INACTIVE, PGA_REQUEUE);
4278 }
4279
4280 void
vm_page_deactivate_noreuse(vm_page_t m)4281 vm_page_deactivate_noreuse(vm_page_t m)
4282 {
4283
4284 vm_page_mvqueue(m, PQ_INACTIVE, PGA_REQUEUE_HEAD);
4285 }
4286
4287 /*
4288 * Put a page in the laundry, or requeue it if it is already there.
4289 */
4290 void
vm_page_launder(vm_page_t m)4291 vm_page_launder(vm_page_t m)
4292 {
4293
4294 vm_page_mvqueue(m, PQ_LAUNDRY, PGA_REQUEUE);
4295 }
4296
4297 /*
4298 * Put a page in the PQ_UNSWAPPABLE holding queue.
4299 */
4300 void
vm_page_unswappable(vm_page_t m)4301 vm_page_unswappable(vm_page_t m)
4302 {
4303
4304 VM_OBJECT_ASSERT_LOCKED(m->object);
4305 KASSERT((m->oflags & VPO_UNMANAGED) == 0,
4306 ("page %p already unswappable", m));
4307
4308 vm_page_dequeue(m);
4309 vm_page_enqueue(m, PQ_UNSWAPPABLE);
4310 }
4311
4312 /*
4313 * Release a page back to the page queues in preparation for unwiring.
4314 */
4315 static void
vm_page_release_toq(vm_page_t m,uint8_t nqueue,const bool noreuse)4316 vm_page_release_toq(vm_page_t m, uint8_t nqueue, const bool noreuse)
4317 {
4318 vm_page_astate_t old, new;
4319 uint16_t nflag;
4320
4321 /*
4322 * Use a check of the valid bits to determine whether we should
4323 * accelerate reclamation of the page. The object lock might not be
4324 * held here, in which case the check is racy. At worst we will either
4325 * accelerate reclamation of a valid page and violate LRU, or
4326 * unnecessarily defer reclamation of an invalid page.
4327 *
4328 * If we were asked to not cache the page, place it near the head of the
4329 * inactive queue so that is reclaimed sooner.
4330 */
4331 if (noreuse || vm_page_none_valid(m)) {
4332 nqueue = PQ_INACTIVE;
4333 nflag = PGA_REQUEUE_HEAD;
4334 } else {
4335 nflag = PGA_REQUEUE;
4336 }
4337
4338 old = vm_page_astate_load(m);
4339 do {
4340 new = old;
4341
4342 /*
4343 * If the page is already in the active queue and we are not
4344 * trying to accelerate reclamation, simply mark it as
4345 * referenced and avoid any queue operations.
4346 */
4347 new.flags &= ~PGA_QUEUE_OP_MASK;
4348 if (nflag != PGA_REQUEUE_HEAD && old.queue == PQ_ACTIVE &&
4349 (old.flags & PGA_ENQUEUED) != 0)
4350 new.flags |= PGA_REFERENCED;
4351 else {
4352 new.flags |= nflag;
4353 new.queue = nqueue;
4354 }
4355 } while (!vm_page_pqstate_commit(m, &old, new));
4356 }
4357
4358 /*
4359 * Unwire a page and either attempt to free it or re-add it to the page queues.
4360 */
4361 void
vm_page_release(vm_page_t m,int flags)4362 vm_page_release(vm_page_t m, int flags)
4363 {
4364 vm_object_t object;
4365
4366 KASSERT((m->oflags & VPO_UNMANAGED) == 0,
4367 ("vm_page_release: page %p is unmanaged", m));
4368
4369 if ((flags & VPR_TRYFREE) != 0) {
4370 for (;;) {
4371 object = atomic_load_ptr(&m->object);
4372 if (object == NULL)
4373 break;
4374 /* Depends on type-stability. */
4375 if (vm_page_busied(m) || !VM_OBJECT_TRYWLOCK(object))
4376 break;
4377 if (object == m->object) {
4378 vm_page_release_locked(m, flags);
4379 VM_OBJECT_WUNLOCK(object);
4380 return;
4381 }
4382 VM_OBJECT_WUNLOCK(object);
4383 }
4384 }
4385 vm_page_unwire_managed(m, PQ_INACTIVE, flags != 0);
4386 }
4387
4388 /* See vm_page_release(). */
4389 void
vm_page_release_locked(vm_page_t m,int flags)4390 vm_page_release_locked(vm_page_t m, int flags)
4391 {
4392
4393 VM_OBJECT_ASSERT_WLOCKED(m->object);
4394 KASSERT((m->oflags & VPO_UNMANAGED) == 0,
4395 ("vm_page_release_locked: page %p is unmanaged", m));
4396
4397 if (vm_page_unwire_noq(m)) {
4398 if ((flags & VPR_TRYFREE) != 0 &&
4399 (m->object->ref_count == 0 || !pmap_page_is_mapped(m)) &&
4400 m->dirty == 0 && vm_page_tryxbusy(m)) {
4401 /*
4402 * An unlocked lookup may have wired the page before the
4403 * busy lock was acquired, in which case the page must
4404 * not be freed.
4405 */
4406 if (__predict_true(!vm_page_wired(m))) {
4407 vm_page_free(m);
4408 return;
4409 }
4410 vm_page_xunbusy(m);
4411 } else {
4412 vm_page_release_toq(m, PQ_INACTIVE, flags != 0);
4413 }
4414 }
4415 }
4416
4417 static bool
vm_page_try_blocked_op(vm_page_t m,void (* op)(vm_page_t))4418 vm_page_try_blocked_op(vm_page_t m, void (*op)(vm_page_t))
4419 {
4420 u_int old;
4421
4422 KASSERT(m->object != NULL && (m->oflags & VPO_UNMANAGED) == 0,
4423 ("vm_page_try_blocked_op: page %p has no object", m));
4424 KASSERT(vm_page_busied(m),
4425 ("vm_page_try_blocked_op: page %p is not busy", m));
4426 VM_OBJECT_ASSERT_LOCKED(m->object);
4427
4428 old = m->ref_count;
4429 do {
4430 KASSERT(old != 0,
4431 ("vm_page_try_blocked_op: page %p has no references", m));
4432 if (VPRC_WIRE_COUNT(old) != 0)
4433 return (false);
4434 } while (!atomic_fcmpset_int(&m->ref_count, &old, old | VPRC_BLOCKED));
4435
4436 (op)(m);
4437
4438 /*
4439 * If the object is read-locked, new wirings may be created via an
4440 * object lookup.
4441 */
4442 old = vm_page_drop(m, VPRC_BLOCKED);
4443 KASSERT(!VM_OBJECT_WOWNED(m->object) ||
4444 old == (VPRC_BLOCKED | VPRC_OBJREF),
4445 ("vm_page_try_blocked_op: unexpected refcount value %u for %p",
4446 old, m));
4447 return (true);
4448 }
4449
4450 /*
4451 * Atomically check for wirings and remove all mappings of the page.
4452 */
4453 bool
vm_page_try_remove_all(vm_page_t m)4454 vm_page_try_remove_all(vm_page_t m)
4455 {
4456
4457 return (vm_page_try_blocked_op(m, pmap_remove_all));
4458 }
4459
4460 /*
4461 * Atomically check for wirings and remove all writeable mappings of the page.
4462 */
4463 bool
vm_page_try_remove_write(vm_page_t m)4464 vm_page_try_remove_write(vm_page_t m)
4465 {
4466
4467 return (vm_page_try_blocked_op(m, pmap_remove_write));
4468 }
4469
4470 /*
4471 * vm_page_advise
4472 *
4473 * Apply the specified advice to the given page.
4474 */
4475 void
vm_page_advise(vm_page_t m,int advice)4476 vm_page_advise(vm_page_t m, int advice)
4477 {
4478
4479 VM_OBJECT_ASSERT_WLOCKED(m->object);
4480 vm_page_assert_xbusied(m);
4481
4482 if (advice == MADV_FREE)
4483 /*
4484 * Mark the page clean. This will allow the page to be freed
4485 * without first paging it out. MADV_FREE pages are often
4486 * quickly reused by malloc(3), so we do not do anything that
4487 * would result in a page fault on a later access.
4488 */
4489 vm_page_undirty(m);
4490 else if (advice != MADV_DONTNEED) {
4491 if (advice == MADV_WILLNEED)
4492 vm_page_activate(m);
4493 return;
4494 }
4495
4496 if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m))
4497 vm_page_dirty(m);
4498
4499 /*
4500 * Clear any references to the page. Otherwise, the page daemon will
4501 * immediately reactivate the page.
4502 */
4503 vm_page_aflag_clear(m, PGA_REFERENCED);
4504
4505 /*
4506 * Place clean pages near the head of the inactive queue rather than
4507 * the tail, thus defeating the queue's LRU operation and ensuring that
4508 * the page will be reused quickly. Dirty pages not already in the
4509 * laundry are moved there.
4510 */
4511 if (m->dirty == 0)
4512 vm_page_deactivate_noreuse(m);
4513 else if (!vm_page_in_laundry(m))
4514 vm_page_launder(m);
4515 }
4516
4517 /*
4518 * vm_page_grab_release
4519 *
4520 * Helper routine for grab functions to release busy on return.
4521 */
4522 static inline void
vm_page_grab_release(vm_page_t m,int allocflags)4523 vm_page_grab_release(vm_page_t m, int allocflags)
4524 {
4525
4526 if ((allocflags & VM_ALLOC_NOBUSY) != 0) {
4527 if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0)
4528 vm_page_sunbusy(m);
4529 else
4530 vm_page_xunbusy(m);
4531 }
4532 }
4533
4534 /*
4535 * vm_page_grab_sleep
4536 *
4537 * Sleep for busy according to VM_ALLOC_ parameters. Returns true
4538 * if the caller should retry and false otherwise.
4539 *
4540 * If the object is locked on entry the object will be unlocked with
4541 * false returns and still locked but possibly having been dropped
4542 * with true returns.
4543 */
4544 static bool
vm_page_grab_sleep(vm_object_t object,vm_page_t m,vm_pindex_t pindex,const char * wmesg,int allocflags,bool locked)4545 vm_page_grab_sleep(vm_object_t object, vm_page_t m, vm_pindex_t pindex,
4546 const char *wmesg, int allocflags, bool locked)
4547 {
4548
4549 if ((allocflags & VM_ALLOC_NOWAIT) != 0)
4550 return (false);
4551
4552 /*
4553 * Reference the page before unlocking and sleeping so that
4554 * the page daemon is less likely to reclaim it.
4555 */
4556 if (locked && (allocflags & VM_ALLOC_NOCREAT) == 0)
4557 vm_page_reference(m);
4558
4559 if (_vm_page_busy_sleep(object, m, pindex, wmesg, allocflags, locked) &&
4560 locked)
4561 VM_OBJECT_WLOCK(object);
4562 if ((allocflags & VM_ALLOC_WAITFAIL) != 0)
4563 return (false);
4564
4565 return (true);
4566 }
4567
4568 /*
4569 * Assert that the grab flags are valid.
4570 */
4571 static inline void
vm_page_grab_check(int allocflags)4572 vm_page_grab_check(int allocflags)
4573 {
4574
4575 KASSERT((allocflags & VM_ALLOC_NOBUSY) == 0 ||
4576 (allocflags & VM_ALLOC_WIRED) != 0,
4577 ("vm_page_grab*: the pages must be busied or wired"));
4578
4579 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 ||
4580 (allocflags & VM_ALLOC_IGN_SBUSY) != 0,
4581 ("vm_page_grab*: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch"));
4582 }
4583
4584 /*
4585 * Calculate the page allocation flags for grab.
4586 */
4587 static inline int
vm_page_grab_pflags(int allocflags)4588 vm_page_grab_pflags(int allocflags)
4589 {
4590 int pflags;
4591
4592 pflags = allocflags &
4593 ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL |
4594 VM_ALLOC_NOBUSY | VM_ALLOC_IGN_SBUSY);
4595 if ((allocflags & VM_ALLOC_NOWAIT) == 0)
4596 pflags |= VM_ALLOC_WAITFAIL;
4597 if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0)
4598 pflags |= VM_ALLOC_SBUSY;
4599
4600 return (pflags);
4601 }
4602
4603 /*
4604 * Grab a page, waiting until we are waken up due to the page
4605 * changing state. We keep on waiting, if the page continues
4606 * to be in the object. If the page doesn't exist, first allocate it
4607 * and then conditionally zero it.
4608 *
4609 * This routine may sleep.
4610 *
4611 * The object must be locked on entry. The lock will, however, be released
4612 * and reacquired if the routine sleeps.
4613 */
4614 vm_page_t
vm_page_grab(vm_object_t object,vm_pindex_t pindex,int allocflags)4615 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags)
4616 {
4617 vm_page_t m;
4618
4619 VM_OBJECT_ASSERT_WLOCKED(object);
4620 vm_page_grab_check(allocflags);
4621
4622 retrylookup:
4623 if ((m = vm_page_lookup(object, pindex)) != NULL) {
4624 if (!vm_page_tryacquire(m, allocflags)) {
4625 if (vm_page_grab_sleep(object, m, pindex, "pgrbwt",
4626 allocflags, true))
4627 goto retrylookup;
4628 return (NULL);
4629 }
4630 goto out;
4631 }
4632 if ((allocflags & VM_ALLOC_NOCREAT) != 0)
4633 return (NULL);
4634 m = vm_page_alloc(object, pindex, vm_page_grab_pflags(allocflags));
4635 if (m == NULL) {
4636 if ((allocflags & (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL)) != 0)
4637 return (NULL);
4638 goto retrylookup;
4639 }
4640 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0)
4641 pmap_zero_page(m);
4642
4643 out:
4644 vm_page_grab_release(m, allocflags);
4645
4646 return (m);
4647 }
4648
4649 /*
4650 * Locklessly attempt to acquire a page given a (object, pindex) tuple
4651 * and an optional previous page to avoid the radix lookup. The resulting
4652 * page will be validated against the identity tuple and busied or wired
4653 * as requested. A NULL *mp return guarantees that the page was not in
4654 * radix at the time of the call but callers must perform higher level
4655 * synchronization or retry the operation under a lock if they require
4656 * an atomic answer. This is the only lock free validation routine,
4657 * other routines can depend on the resulting page state.
4658 *
4659 * The return value indicates whether the operation failed due to caller
4660 * flags. The return is tri-state with mp:
4661 *
4662 * (true, *mp != NULL) - The operation was successful.
4663 * (true, *mp == NULL) - The page was not found in tree.
4664 * (false, *mp == NULL) - WAITFAIL or NOWAIT prevented acquisition.
4665 */
4666 static bool
vm_page_acquire_unlocked(vm_object_t object,vm_pindex_t pindex,vm_page_t prev,vm_page_t * mp,int allocflags)4667 vm_page_acquire_unlocked(vm_object_t object, vm_pindex_t pindex,
4668 vm_page_t prev, vm_page_t *mp, int allocflags)
4669 {
4670 vm_page_t m;
4671
4672 vm_page_grab_check(allocflags);
4673 MPASS(prev == NULL || vm_page_busied(prev) || vm_page_wired(prev));
4674
4675 *mp = NULL;
4676 for (;;) {
4677 /*
4678 * We may see a false NULL here because the previous page
4679 * has been removed or just inserted and the list is loaded
4680 * without barriers. Switch to radix to verify.
4681 */
4682 if (prev == NULL || (m = TAILQ_NEXT(prev, listq)) == NULL ||
4683 QMD_IS_TRASHED(m) || m->pindex != pindex ||
4684 atomic_load_ptr(&m->object) != object) {
4685 prev = NULL;
4686 /*
4687 * This guarantees the result is instantaneously
4688 * correct.
4689 */
4690 m = vm_radix_lookup_unlocked(&object->rtree, pindex);
4691 }
4692 if (m == NULL)
4693 return (true);
4694 if (vm_page_trybusy(m, allocflags)) {
4695 if (m->object == object && m->pindex == pindex)
4696 break;
4697 /* relookup. */
4698 vm_page_busy_release(m);
4699 cpu_spinwait();
4700 continue;
4701 }
4702 if (!vm_page_grab_sleep(object, m, pindex, "pgnslp",
4703 allocflags, false))
4704 return (false);
4705 }
4706 if ((allocflags & VM_ALLOC_WIRED) != 0)
4707 vm_page_wire(m);
4708 vm_page_grab_release(m, allocflags);
4709 *mp = m;
4710 return (true);
4711 }
4712
4713 /*
4714 * Try to locklessly grab a page and fall back to the object lock if NOCREAT
4715 * is not set.
4716 */
4717 vm_page_t
vm_page_grab_unlocked(vm_object_t object,vm_pindex_t pindex,int allocflags)4718 vm_page_grab_unlocked(vm_object_t object, vm_pindex_t pindex, int allocflags)
4719 {
4720 vm_page_t m;
4721
4722 vm_page_grab_check(allocflags);
4723
4724 if (!vm_page_acquire_unlocked(object, pindex, NULL, &m, allocflags))
4725 return (NULL);
4726 if (m != NULL)
4727 return (m);
4728
4729 /*
4730 * The radix lockless lookup should never return a false negative
4731 * errors. If the user specifies NOCREAT they are guaranteed there
4732 * was no page present at the instant of the call. A NOCREAT caller
4733 * must handle create races gracefully.
4734 */
4735 if ((allocflags & VM_ALLOC_NOCREAT) != 0)
4736 return (NULL);
4737
4738 VM_OBJECT_WLOCK(object);
4739 m = vm_page_grab(object, pindex, allocflags);
4740 VM_OBJECT_WUNLOCK(object);
4741
4742 return (m);
4743 }
4744
4745 /*
4746 * Grab a page and make it valid, paging in if necessary. Pages missing from
4747 * their pager are zero filled and validated. If a VM_ALLOC_COUNT is supplied
4748 * and the page is not valid as many as VM_INITIAL_PAGEIN pages can be brought
4749 * in simultaneously. Additional pages will be left on a paging queue but
4750 * will neither be wired nor busy regardless of allocflags.
4751 */
4752 int
vm_page_grab_valid(vm_page_t * mp,vm_object_t object,vm_pindex_t pindex,int allocflags)4753 vm_page_grab_valid(vm_page_t *mp, vm_object_t object, vm_pindex_t pindex, int allocflags)
4754 {
4755 vm_page_t m;
4756 vm_page_t ma[VM_INITIAL_PAGEIN];
4757 int after, i, pflags, rv;
4758
4759 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 ||
4760 (allocflags & VM_ALLOC_IGN_SBUSY) != 0,
4761 ("vm_page_grab_valid: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch"));
4762 KASSERT((allocflags &
4763 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0,
4764 ("vm_page_grab_valid: Invalid flags 0x%X", allocflags));
4765 VM_OBJECT_ASSERT_WLOCKED(object);
4766 pflags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY |
4767 VM_ALLOC_WIRED | VM_ALLOC_IGN_SBUSY);
4768 pflags |= VM_ALLOC_WAITFAIL;
4769
4770 retrylookup:
4771 if ((m = vm_page_lookup(object, pindex)) != NULL) {
4772 /*
4773 * If the page is fully valid it can only become invalid
4774 * with the object lock held. If it is not valid it can
4775 * become valid with the busy lock held. Therefore, we
4776 * may unnecessarily lock the exclusive busy here if we
4777 * race with I/O completion not using the object lock.
4778 * However, we will not end up with an invalid page and a
4779 * shared lock.
4780 */
4781 if (!vm_page_trybusy(m,
4782 vm_page_all_valid(m) ? allocflags : 0)) {
4783 (void)vm_page_grab_sleep(object, m, pindex, "pgrbwt",
4784 allocflags, true);
4785 goto retrylookup;
4786 }
4787 if (vm_page_all_valid(m))
4788 goto out;
4789 if ((allocflags & VM_ALLOC_NOCREAT) != 0) {
4790 vm_page_busy_release(m);
4791 *mp = NULL;
4792 return (VM_PAGER_FAIL);
4793 }
4794 } else if ((allocflags & VM_ALLOC_NOCREAT) != 0) {
4795 *mp = NULL;
4796 return (VM_PAGER_FAIL);
4797 } else if ((m = vm_page_alloc(object, pindex, pflags)) == NULL) {
4798 if (!vm_pager_can_alloc_page(object, pindex)) {
4799 *mp = NULL;
4800 return (VM_PAGER_AGAIN);
4801 }
4802 goto retrylookup;
4803 }
4804
4805 vm_page_assert_xbusied(m);
4806 if (vm_pager_has_page(object, pindex, NULL, &after)) {
4807 after = MIN(after, VM_INITIAL_PAGEIN);
4808 after = MIN(after, allocflags >> VM_ALLOC_COUNT_SHIFT);
4809 after = MAX(after, 1);
4810 ma[0] = m;
4811 for (i = 1; i < after; i++) {
4812 if ((ma[i] = vm_page_next(ma[i - 1])) != NULL) {
4813 if (vm_page_any_valid(ma[i]) ||
4814 !vm_page_tryxbusy(ma[i]))
4815 break;
4816 } else {
4817 ma[i] = vm_page_alloc(object, m->pindex + i,
4818 VM_ALLOC_NORMAL);
4819 if (ma[i] == NULL)
4820 break;
4821 }
4822 }
4823 after = i;
4824 vm_object_pip_add(object, after);
4825 VM_OBJECT_WUNLOCK(object);
4826 rv = vm_pager_get_pages(object, ma, after, NULL, NULL);
4827 VM_OBJECT_WLOCK(object);
4828 vm_object_pip_wakeupn(object, after);
4829 /* Pager may have replaced a page. */
4830 m = ma[0];
4831 if (rv != VM_PAGER_OK) {
4832 for (i = 0; i < after; i++) {
4833 if (!vm_page_wired(ma[i]))
4834 vm_page_free(ma[i]);
4835 else
4836 vm_page_xunbusy(ma[i]);
4837 }
4838 *mp = NULL;
4839 return (rv);
4840 }
4841 for (i = 1; i < after; i++)
4842 vm_page_readahead_finish(ma[i]);
4843 MPASS(vm_page_all_valid(m));
4844 } else {
4845 vm_page_zero_invalid(m, TRUE);
4846 }
4847 out:
4848 if ((allocflags & VM_ALLOC_WIRED) != 0)
4849 vm_page_wire(m);
4850 if ((allocflags & VM_ALLOC_SBUSY) != 0 && vm_page_xbusied(m))
4851 vm_page_busy_downgrade(m);
4852 else if ((allocflags & VM_ALLOC_NOBUSY) != 0)
4853 vm_page_busy_release(m);
4854 *mp = m;
4855 return (VM_PAGER_OK);
4856 }
4857
4858 /*
4859 * Locklessly grab a valid page. If the page is not valid or not yet
4860 * allocated this will fall back to the object lock method.
4861 */
4862 int
vm_page_grab_valid_unlocked(vm_page_t * mp,vm_object_t object,vm_pindex_t pindex,int allocflags)4863 vm_page_grab_valid_unlocked(vm_page_t *mp, vm_object_t object,
4864 vm_pindex_t pindex, int allocflags)
4865 {
4866 vm_page_t m;
4867 int flags;
4868 int error;
4869
4870 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 ||
4871 (allocflags & VM_ALLOC_IGN_SBUSY) != 0,
4872 ("vm_page_grab_valid_unlocked: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY "
4873 "mismatch"));
4874 KASSERT((allocflags &
4875 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0,
4876 ("vm_page_grab_valid_unlocked: Invalid flags 0x%X", allocflags));
4877
4878 /*
4879 * Attempt a lockless lookup and busy. We need at least an sbusy
4880 * before we can inspect the valid field and return a wired page.
4881 */
4882 flags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_WIRED);
4883 if (!vm_page_acquire_unlocked(object, pindex, NULL, mp, flags))
4884 return (VM_PAGER_FAIL);
4885 if ((m = *mp) != NULL) {
4886 if (vm_page_all_valid(m)) {
4887 if ((allocflags & VM_ALLOC_WIRED) != 0)
4888 vm_page_wire(m);
4889 vm_page_grab_release(m, allocflags);
4890 return (VM_PAGER_OK);
4891 }
4892 vm_page_busy_release(m);
4893 }
4894 if ((allocflags & VM_ALLOC_NOCREAT) != 0) {
4895 *mp = NULL;
4896 return (VM_PAGER_FAIL);
4897 }
4898 VM_OBJECT_WLOCK(object);
4899 error = vm_page_grab_valid(mp, object, pindex, allocflags);
4900 VM_OBJECT_WUNLOCK(object);
4901
4902 return (error);
4903 }
4904
4905 /*
4906 * Return the specified range of pages from the given object. For each
4907 * page offset within the range, if a page already exists within the object
4908 * at that offset and it is busy, then wait for it to change state. If,
4909 * instead, the page doesn't exist, then allocate it.
4910 *
4911 * The caller must always specify an allocation class.
4912 *
4913 * allocation classes:
4914 * VM_ALLOC_NORMAL normal process request
4915 * VM_ALLOC_SYSTEM system *really* needs the pages
4916 *
4917 * The caller must always specify that the pages are to be busied and/or
4918 * wired.
4919 *
4920 * optional allocation flags:
4921 * VM_ALLOC_IGN_SBUSY do not sleep on soft busy pages
4922 * VM_ALLOC_NOBUSY do not exclusive busy the page
4923 * VM_ALLOC_NOWAIT do not sleep
4924 * VM_ALLOC_SBUSY set page to sbusy state
4925 * VM_ALLOC_WIRED wire the pages
4926 * VM_ALLOC_ZERO zero and validate any invalid pages
4927 *
4928 * If VM_ALLOC_NOWAIT is not specified, this routine may sleep. Otherwise, it
4929 * may return a partial prefix of the requested range.
4930 */
4931 int
vm_page_grab_pages(vm_object_t object,vm_pindex_t pindex,int allocflags,vm_page_t * ma,int count)4932 vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags,
4933 vm_page_t *ma, int count)
4934 {
4935 vm_page_t m, mpred;
4936 int pflags;
4937 int i;
4938
4939 VM_OBJECT_ASSERT_WLOCKED(object);
4940 KASSERT(((u_int)allocflags >> VM_ALLOC_COUNT_SHIFT) == 0,
4941 ("vm_page_grap_pages: VM_ALLOC_COUNT() is not allowed"));
4942 KASSERT(count > 0,
4943 ("vm_page_grab_pages: invalid page count %d", count));
4944 vm_page_grab_check(allocflags);
4945
4946 pflags = vm_page_grab_pflags(allocflags);
4947 i = 0;
4948 retrylookup:
4949 m = vm_radix_lookup_le(&object->rtree, pindex + i);
4950 if (m == NULL || m->pindex != pindex + i) {
4951 mpred = m;
4952 m = NULL;
4953 } else
4954 mpred = TAILQ_PREV(m, pglist, listq);
4955 for (; i < count; i++) {
4956 if (m != NULL) {
4957 if (!vm_page_tryacquire(m, allocflags)) {
4958 if (vm_page_grab_sleep(object, m, pindex + i,
4959 "grbmaw", allocflags, true))
4960 goto retrylookup;
4961 break;
4962 }
4963 } else {
4964 if ((allocflags & VM_ALLOC_NOCREAT) != 0)
4965 break;
4966 m = vm_page_alloc_after(object, pindex + i,
4967 pflags | VM_ALLOC_COUNT(count - i), mpred);
4968 if (m == NULL) {
4969 if ((allocflags & (VM_ALLOC_NOWAIT |
4970 VM_ALLOC_WAITFAIL)) != 0)
4971 break;
4972 goto retrylookup;
4973 }
4974 }
4975 if (vm_page_none_valid(m) &&
4976 (allocflags & VM_ALLOC_ZERO) != 0) {
4977 if ((m->flags & PG_ZERO) == 0)
4978 pmap_zero_page(m);
4979 vm_page_valid(m);
4980 }
4981 vm_page_grab_release(m, allocflags);
4982 ma[i] = mpred = m;
4983 m = vm_page_next(m);
4984 }
4985 return (i);
4986 }
4987
4988 /*
4989 * Unlocked variant of vm_page_grab_pages(). This accepts the same flags
4990 * and will fall back to the locked variant to handle allocation.
4991 */
4992 int
vm_page_grab_pages_unlocked(vm_object_t object,vm_pindex_t pindex,int allocflags,vm_page_t * ma,int count)4993 vm_page_grab_pages_unlocked(vm_object_t object, vm_pindex_t pindex,
4994 int allocflags, vm_page_t *ma, int count)
4995 {
4996 vm_page_t m, pred;
4997 int flags;
4998 int i;
4999
5000 KASSERT(count > 0,
5001 ("vm_page_grab_pages_unlocked: invalid page count %d", count));
5002 vm_page_grab_check(allocflags);
5003
5004 /*
5005 * Modify flags for lockless acquire to hold the page until we
5006 * set it valid if necessary.
5007 */
5008 flags = allocflags & ~VM_ALLOC_NOBUSY;
5009 pred = NULL;
5010 for (i = 0; i < count; i++, pindex++) {
5011 if (!vm_page_acquire_unlocked(object, pindex, pred, &m, flags))
5012 return (i);
5013 if (m == NULL)
5014 break;
5015 if ((flags & VM_ALLOC_ZERO) != 0 && vm_page_none_valid(m)) {
5016 if ((m->flags & PG_ZERO) == 0)
5017 pmap_zero_page(m);
5018 vm_page_valid(m);
5019 }
5020 /* m will still be wired or busy according to flags. */
5021 vm_page_grab_release(m, allocflags);
5022 pred = ma[i] = m;
5023 }
5024 if (i == count || (allocflags & VM_ALLOC_NOCREAT) != 0)
5025 return (i);
5026 count -= i;
5027 VM_OBJECT_WLOCK(object);
5028 i += vm_page_grab_pages(object, pindex, allocflags, &ma[i], count);
5029 VM_OBJECT_WUNLOCK(object);
5030
5031 return (i);
5032 }
5033
5034 /*
5035 * Mapping function for valid or dirty bits in a page.
5036 *
5037 * Inputs are required to range within a page.
5038 */
5039 vm_page_bits_t
vm_page_bits(int base,int size)5040 vm_page_bits(int base, int size)
5041 {
5042 int first_bit;
5043 int last_bit;
5044
5045 KASSERT(
5046 base + size <= PAGE_SIZE,
5047 ("vm_page_bits: illegal base/size %d/%d", base, size)
5048 );
5049
5050 if (size == 0) /* handle degenerate case */
5051 return (0);
5052
5053 first_bit = base >> DEV_BSHIFT;
5054 last_bit = (base + size - 1) >> DEV_BSHIFT;
5055
5056 return (((vm_page_bits_t)2 << last_bit) -
5057 ((vm_page_bits_t)1 << first_bit));
5058 }
5059
5060 void
vm_page_bits_set(vm_page_t m,vm_page_bits_t * bits,vm_page_bits_t set)5061 vm_page_bits_set(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t set)
5062 {
5063
5064 #if PAGE_SIZE == 32768
5065 atomic_set_64((uint64_t *)bits, set);
5066 #elif PAGE_SIZE == 16384
5067 atomic_set_32((uint32_t *)bits, set);
5068 #elif (PAGE_SIZE == 8192) && defined(atomic_set_16)
5069 atomic_set_16((uint16_t *)bits, set);
5070 #elif (PAGE_SIZE == 4096) && defined(atomic_set_8)
5071 atomic_set_8((uint8_t *)bits, set);
5072 #else /* PAGE_SIZE <= 8192 */
5073 uintptr_t addr;
5074 int shift;
5075
5076 addr = (uintptr_t)bits;
5077 /*
5078 * Use a trick to perform a 32-bit atomic on the
5079 * containing aligned word, to not depend on the existence
5080 * of atomic_{set, clear}_{8, 16}.
5081 */
5082 shift = addr & (sizeof(uint32_t) - 1);
5083 #if BYTE_ORDER == BIG_ENDIAN
5084 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY;
5085 #else
5086 shift *= NBBY;
5087 #endif
5088 addr &= ~(sizeof(uint32_t) - 1);
5089 atomic_set_32((uint32_t *)addr, set << shift);
5090 #endif /* PAGE_SIZE */
5091 }
5092
5093 static inline void
vm_page_bits_clear(vm_page_t m,vm_page_bits_t * bits,vm_page_bits_t clear)5094 vm_page_bits_clear(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t clear)
5095 {
5096
5097 #if PAGE_SIZE == 32768
5098 atomic_clear_64((uint64_t *)bits, clear);
5099 #elif PAGE_SIZE == 16384
5100 atomic_clear_32((uint32_t *)bits, clear);
5101 #elif (PAGE_SIZE == 8192) && defined(atomic_clear_16)
5102 atomic_clear_16((uint16_t *)bits, clear);
5103 #elif (PAGE_SIZE == 4096) && defined(atomic_clear_8)
5104 atomic_clear_8((uint8_t *)bits, clear);
5105 #else /* PAGE_SIZE <= 8192 */
5106 uintptr_t addr;
5107 int shift;
5108
5109 addr = (uintptr_t)bits;
5110 /*
5111 * Use a trick to perform a 32-bit atomic on the
5112 * containing aligned word, to not depend on the existence
5113 * of atomic_{set, clear}_{8, 16}.
5114 */
5115 shift = addr & (sizeof(uint32_t) - 1);
5116 #if BYTE_ORDER == BIG_ENDIAN
5117 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY;
5118 #else
5119 shift *= NBBY;
5120 #endif
5121 addr &= ~(sizeof(uint32_t) - 1);
5122 atomic_clear_32((uint32_t *)addr, clear << shift);
5123 #endif /* PAGE_SIZE */
5124 }
5125
5126 static inline vm_page_bits_t
vm_page_bits_swap(vm_page_t m,vm_page_bits_t * bits,vm_page_bits_t newbits)5127 vm_page_bits_swap(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t newbits)
5128 {
5129 #if PAGE_SIZE == 32768
5130 uint64_t old;
5131
5132 old = *bits;
5133 while (atomic_fcmpset_64(bits, &old, newbits) == 0);
5134 return (old);
5135 #elif PAGE_SIZE == 16384
5136 uint32_t old;
5137
5138 old = *bits;
5139 while (atomic_fcmpset_32(bits, &old, newbits) == 0);
5140 return (old);
5141 #elif (PAGE_SIZE == 8192) && defined(atomic_fcmpset_16)
5142 uint16_t old;
5143
5144 old = *bits;
5145 while (atomic_fcmpset_16(bits, &old, newbits) == 0);
5146 return (old);
5147 #elif (PAGE_SIZE == 4096) && defined(atomic_fcmpset_8)
5148 uint8_t old;
5149
5150 old = *bits;
5151 while (atomic_fcmpset_8(bits, &old, newbits) == 0);
5152 return (old);
5153 #else /* PAGE_SIZE <= 4096*/
5154 uintptr_t addr;
5155 uint32_t old, new, mask;
5156 int shift;
5157
5158 addr = (uintptr_t)bits;
5159 /*
5160 * Use a trick to perform a 32-bit atomic on the
5161 * containing aligned word, to not depend on the existence
5162 * of atomic_{set, swap, clear}_{8, 16}.
5163 */
5164 shift = addr & (sizeof(uint32_t) - 1);
5165 #if BYTE_ORDER == BIG_ENDIAN
5166 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY;
5167 #else
5168 shift *= NBBY;
5169 #endif
5170 addr &= ~(sizeof(uint32_t) - 1);
5171 mask = VM_PAGE_BITS_ALL << shift;
5172
5173 old = *bits;
5174 do {
5175 new = old & ~mask;
5176 new |= newbits << shift;
5177 } while (atomic_fcmpset_32((uint32_t *)addr, &old, new) == 0);
5178 return (old >> shift);
5179 #endif /* PAGE_SIZE */
5180 }
5181
5182 /*
5183 * vm_page_set_valid_range:
5184 *
5185 * Sets portions of a page valid. The arguments are expected
5186 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive
5187 * of any partial chunks touched by the range. The invalid portion of
5188 * such chunks will be zeroed.
5189 *
5190 * (base + size) must be less then or equal to PAGE_SIZE.
5191 */
5192 void
vm_page_set_valid_range(vm_page_t m,int base,int size)5193 vm_page_set_valid_range(vm_page_t m, int base, int size)
5194 {
5195 int endoff, frag;
5196 vm_page_bits_t pagebits;
5197
5198 vm_page_assert_busied(m);
5199 if (size == 0) /* handle degenerate case */
5200 return;
5201
5202 /*
5203 * If the base is not DEV_BSIZE aligned and the valid
5204 * bit is clear, we have to zero out a portion of the
5205 * first block.
5206 */
5207 if ((frag = rounddown2(base, DEV_BSIZE)) != base &&
5208 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0)
5209 pmap_zero_page_area(m, frag, base - frag);
5210
5211 /*
5212 * If the ending offset is not DEV_BSIZE aligned and the
5213 * valid bit is clear, we have to zero out a portion of
5214 * the last block.
5215 */
5216 endoff = base + size;
5217 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff &&
5218 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0)
5219 pmap_zero_page_area(m, endoff,
5220 DEV_BSIZE - (endoff & (DEV_BSIZE - 1)));
5221
5222 /*
5223 * Assert that no previously invalid block that is now being validated
5224 * is already dirty.
5225 */
5226 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0,
5227 ("vm_page_set_valid_range: page %p is dirty", m));
5228
5229 /*
5230 * Set valid bits inclusive of any overlap.
5231 */
5232 pagebits = vm_page_bits(base, size);
5233 if (vm_page_xbusied(m))
5234 m->valid |= pagebits;
5235 else
5236 vm_page_bits_set(m, &m->valid, pagebits);
5237 }
5238
5239 /*
5240 * Set the page dirty bits and free the invalid swap space if
5241 * present. Returns the previous dirty bits.
5242 */
5243 vm_page_bits_t
vm_page_set_dirty(vm_page_t m)5244 vm_page_set_dirty(vm_page_t m)
5245 {
5246 vm_page_bits_t old;
5247
5248 VM_PAGE_OBJECT_BUSY_ASSERT(m);
5249
5250 if (vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) {
5251 old = m->dirty;
5252 m->dirty = VM_PAGE_BITS_ALL;
5253 } else
5254 old = vm_page_bits_swap(m, &m->dirty, VM_PAGE_BITS_ALL);
5255 if (old == 0 && (m->a.flags & PGA_SWAP_SPACE) != 0)
5256 vm_pager_page_unswapped(m);
5257
5258 return (old);
5259 }
5260
5261 /*
5262 * Clear the given bits from the specified page's dirty field.
5263 */
5264 static __inline void
vm_page_clear_dirty_mask(vm_page_t m,vm_page_bits_t pagebits)5265 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits)
5266 {
5267
5268 vm_page_assert_busied(m);
5269
5270 /*
5271 * If the page is xbusied and not write mapped we are the
5272 * only thread that can modify dirty bits. Otherwise, The pmap
5273 * layer can call vm_page_dirty() without holding a distinguished
5274 * lock. The combination of page busy and atomic operations
5275 * suffice to guarantee consistency of the page dirty field.
5276 */
5277 if (vm_page_xbusied(m) && !pmap_page_is_write_mapped(m))
5278 m->dirty &= ~pagebits;
5279 else
5280 vm_page_bits_clear(m, &m->dirty, pagebits);
5281 }
5282
5283 /*
5284 * vm_page_set_validclean:
5285 *
5286 * Sets portions of a page valid and clean. The arguments are expected
5287 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive
5288 * of any partial chunks touched by the range. The invalid portion of
5289 * such chunks will be zero'd.
5290 *
5291 * (base + size) must be less then or equal to PAGE_SIZE.
5292 */
5293 void
vm_page_set_validclean(vm_page_t m,int base,int size)5294 vm_page_set_validclean(vm_page_t m, int base, int size)
5295 {
5296 vm_page_bits_t oldvalid, pagebits;
5297 int endoff, frag;
5298
5299 vm_page_assert_busied(m);
5300 if (size == 0) /* handle degenerate case */
5301 return;
5302
5303 /*
5304 * If the base is not DEV_BSIZE aligned and the valid
5305 * bit is clear, we have to zero out a portion of the
5306 * first block.
5307 */
5308 if ((frag = rounddown2(base, DEV_BSIZE)) != base &&
5309 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0)
5310 pmap_zero_page_area(m, frag, base - frag);
5311
5312 /*
5313 * If the ending offset is not DEV_BSIZE aligned and the
5314 * valid bit is clear, we have to zero out a portion of
5315 * the last block.
5316 */
5317 endoff = base + size;
5318 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff &&
5319 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0)
5320 pmap_zero_page_area(m, endoff,
5321 DEV_BSIZE - (endoff & (DEV_BSIZE - 1)));
5322
5323 /*
5324 * Set valid, clear dirty bits. If validating the entire
5325 * page we can safely clear the pmap modify bit. We also
5326 * use this opportunity to clear the PGA_NOSYNC flag. If a process
5327 * takes a write fault on a MAP_NOSYNC memory area the flag will
5328 * be set again.
5329 *
5330 * We set valid bits inclusive of any overlap, but we can only
5331 * clear dirty bits for DEV_BSIZE chunks that are fully within
5332 * the range.
5333 */
5334 oldvalid = m->valid;
5335 pagebits = vm_page_bits(base, size);
5336 if (vm_page_xbusied(m))
5337 m->valid |= pagebits;
5338 else
5339 vm_page_bits_set(m, &m->valid, pagebits);
5340 #if 0 /* NOT YET */
5341 if ((frag = base & (DEV_BSIZE - 1)) != 0) {
5342 frag = DEV_BSIZE - frag;
5343 base += frag;
5344 size -= frag;
5345 if (size < 0)
5346 size = 0;
5347 }
5348 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1));
5349 #endif
5350 if (base == 0 && size == PAGE_SIZE) {
5351 /*
5352 * The page can only be modified within the pmap if it is
5353 * mapped, and it can only be mapped if it was previously
5354 * fully valid.
5355 */
5356 if (oldvalid == VM_PAGE_BITS_ALL)
5357 /*
5358 * Perform the pmap_clear_modify() first. Otherwise,
5359 * a concurrent pmap operation, such as
5360 * pmap_protect(), could clear a modification in the
5361 * pmap and set the dirty field on the page before
5362 * pmap_clear_modify() had begun and after the dirty
5363 * field was cleared here.
5364 */
5365 pmap_clear_modify(m);
5366 m->dirty = 0;
5367 vm_page_aflag_clear(m, PGA_NOSYNC);
5368 } else if (oldvalid != VM_PAGE_BITS_ALL && vm_page_xbusied(m))
5369 m->dirty &= ~pagebits;
5370 else
5371 vm_page_clear_dirty_mask(m, pagebits);
5372 }
5373
5374 void
vm_page_clear_dirty(vm_page_t m,int base,int size)5375 vm_page_clear_dirty(vm_page_t m, int base, int size)
5376 {
5377
5378 vm_page_clear_dirty_mask(m, vm_page_bits(base, size));
5379 }
5380
5381 /*
5382 * vm_page_set_invalid:
5383 *
5384 * Invalidates DEV_BSIZE'd chunks within a page. Both the
5385 * valid and dirty bits for the effected areas are cleared.
5386 */
5387 void
vm_page_set_invalid(vm_page_t m,int base,int size)5388 vm_page_set_invalid(vm_page_t m, int base, int size)
5389 {
5390 vm_page_bits_t bits;
5391 vm_object_t object;
5392
5393 /*
5394 * The object lock is required so that pages can't be mapped
5395 * read-only while we're in the process of invalidating them.
5396 */
5397 object = m->object;
5398 VM_OBJECT_ASSERT_WLOCKED(object);
5399 vm_page_assert_busied(m);
5400
5401 if (object->type == OBJT_VNODE && base == 0 && IDX_TO_OFF(m->pindex) +
5402 size >= object->un_pager.vnp.vnp_size)
5403 bits = VM_PAGE_BITS_ALL;
5404 else
5405 bits = vm_page_bits(base, size);
5406 if (object->ref_count != 0 && vm_page_all_valid(m) && bits != 0)
5407 pmap_remove_all(m);
5408 KASSERT((bits == 0 && vm_page_all_valid(m)) ||
5409 !pmap_page_is_mapped(m),
5410 ("vm_page_set_invalid: page %p is mapped", m));
5411 if (vm_page_xbusied(m)) {
5412 m->valid &= ~bits;
5413 m->dirty &= ~bits;
5414 } else {
5415 vm_page_bits_clear(m, &m->valid, bits);
5416 vm_page_bits_clear(m, &m->dirty, bits);
5417 }
5418 }
5419
5420 /*
5421 * vm_page_invalid:
5422 *
5423 * Invalidates the entire page. The page must be busy, unmapped, and
5424 * the enclosing object must be locked. The object locks protects
5425 * against concurrent read-only pmap enter which is done without
5426 * busy.
5427 */
5428 void
vm_page_invalid(vm_page_t m)5429 vm_page_invalid(vm_page_t m)
5430 {
5431
5432 vm_page_assert_busied(m);
5433 VM_OBJECT_ASSERT_WLOCKED(m->object);
5434 MPASS(!pmap_page_is_mapped(m));
5435
5436 if (vm_page_xbusied(m))
5437 m->valid = 0;
5438 else
5439 vm_page_bits_clear(m, &m->valid, VM_PAGE_BITS_ALL);
5440 }
5441
5442 /*
5443 * vm_page_zero_invalid()
5444 *
5445 * The kernel assumes that the invalid portions of a page contain
5446 * garbage, but such pages can be mapped into memory by user code.
5447 * When this occurs, we must zero out the non-valid portions of the
5448 * page so user code sees what it expects.
5449 *
5450 * Pages are most often semi-valid when the end of a file is mapped
5451 * into memory and the file's size is not page aligned.
5452 */
5453 void
vm_page_zero_invalid(vm_page_t m,boolean_t setvalid)5454 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid)
5455 {
5456 int b;
5457 int i;
5458
5459 /*
5460 * Scan the valid bits looking for invalid sections that
5461 * must be zeroed. Invalid sub-DEV_BSIZE'd areas ( where the
5462 * valid bit may be set ) have already been zeroed by
5463 * vm_page_set_validclean().
5464 */
5465 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) {
5466 if (i == (PAGE_SIZE / DEV_BSIZE) ||
5467 (m->valid & ((vm_page_bits_t)1 << i))) {
5468 if (i > b) {
5469 pmap_zero_page_area(m,
5470 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT);
5471 }
5472 b = i + 1;
5473 }
5474 }
5475
5476 /*
5477 * setvalid is TRUE when we can safely set the zero'd areas
5478 * as being valid. We can do this if there are no cache consistency
5479 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS.
5480 */
5481 if (setvalid)
5482 vm_page_valid(m);
5483 }
5484
5485 /*
5486 * vm_page_is_valid:
5487 *
5488 * Is (partial) page valid? Note that the case where size == 0
5489 * will return FALSE in the degenerate case where the page is
5490 * entirely invalid, and TRUE otherwise.
5491 *
5492 * Some callers envoke this routine without the busy lock held and
5493 * handle races via higher level locks. Typical callers should
5494 * hold a busy lock to prevent invalidation.
5495 */
5496 int
vm_page_is_valid(vm_page_t m,int base,int size)5497 vm_page_is_valid(vm_page_t m, int base, int size)
5498 {
5499 vm_page_bits_t bits;
5500
5501 bits = vm_page_bits(base, size);
5502 return (vm_page_any_valid(m) && (m->valid & bits) == bits);
5503 }
5504
5505 /*
5506 * Returns true if all of the specified predicates are true for the entire
5507 * (super)page and false otherwise.
5508 */
5509 bool
vm_page_ps_test(vm_page_t m,int flags,vm_page_t skip_m)5510 vm_page_ps_test(vm_page_t m, int flags, vm_page_t skip_m)
5511 {
5512 vm_object_t object;
5513 int i, npages;
5514
5515 object = m->object;
5516 if (skip_m != NULL && skip_m->object != object)
5517 return (false);
5518 VM_OBJECT_ASSERT_LOCKED(object);
5519 npages = atop(pagesizes[m->psind]);
5520
5521 /*
5522 * The physically contiguous pages that make up a superpage, i.e., a
5523 * page with a page size index ("psind") greater than zero, will
5524 * occupy adjacent entries in vm_page_array[].
5525 */
5526 for (i = 0; i < npages; i++) {
5527 /* Always test object consistency, including "skip_m". */
5528 if (m[i].object != object)
5529 return (false);
5530 if (&m[i] == skip_m)
5531 continue;
5532 if ((flags & PS_NONE_BUSY) != 0 && vm_page_busied(&m[i]))
5533 return (false);
5534 if ((flags & PS_ALL_DIRTY) != 0) {
5535 /*
5536 * Calling vm_page_test_dirty() or pmap_is_modified()
5537 * might stop this case from spuriously returning
5538 * "false". However, that would require a write lock
5539 * on the object containing "m[i]".
5540 */
5541 if (m[i].dirty != VM_PAGE_BITS_ALL)
5542 return (false);
5543 }
5544 if ((flags & PS_ALL_VALID) != 0 &&
5545 m[i].valid != VM_PAGE_BITS_ALL)
5546 return (false);
5547 }
5548 return (true);
5549 }
5550
5551 /*
5552 * Set the page's dirty bits if the page is modified.
5553 */
5554 void
vm_page_test_dirty(vm_page_t m)5555 vm_page_test_dirty(vm_page_t m)
5556 {
5557
5558 vm_page_assert_busied(m);
5559 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m))
5560 vm_page_dirty(m);
5561 }
5562
5563 void
vm_page_valid(vm_page_t m)5564 vm_page_valid(vm_page_t m)
5565 {
5566
5567 vm_page_assert_busied(m);
5568 if (vm_page_xbusied(m))
5569 m->valid = VM_PAGE_BITS_ALL;
5570 else
5571 vm_page_bits_set(m, &m->valid, VM_PAGE_BITS_ALL);
5572 }
5573
5574 void
vm_page_lock_KBI(vm_page_t m,const char * file,int line)5575 vm_page_lock_KBI(vm_page_t m, const char *file, int line)
5576 {
5577
5578 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line);
5579 }
5580
5581 void
vm_page_unlock_KBI(vm_page_t m,const char * file,int line)5582 vm_page_unlock_KBI(vm_page_t m, const char *file, int line)
5583 {
5584
5585 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line);
5586 }
5587
5588 int
vm_page_trylock_KBI(vm_page_t m,const char * file,int line)5589 vm_page_trylock_KBI(vm_page_t m, const char *file, int line)
5590 {
5591
5592 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line));
5593 }
5594
5595 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
5596 void
vm_page_assert_locked_KBI(vm_page_t m,const char * file,int line)5597 vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line)
5598 {
5599
5600 vm_page_lock_assert_KBI(m, MA_OWNED, file, line);
5601 }
5602
5603 void
vm_page_lock_assert_KBI(vm_page_t m,int a,const char * file,int line)5604 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line)
5605 {
5606
5607 mtx_assert_(vm_page_lockptr(m), a, file, line);
5608 }
5609 #endif
5610
5611 #ifdef INVARIANTS
5612 void
vm_page_object_busy_assert(vm_page_t m)5613 vm_page_object_busy_assert(vm_page_t m)
5614 {
5615
5616 /*
5617 * Certain of the page's fields may only be modified by the
5618 * holder of a page or object busy.
5619 */
5620 if (m->object != NULL && !vm_page_busied(m))
5621 VM_OBJECT_ASSERT_BUSY(m->object);
5622 }
5623
5624 void
vm_page_assert_pga_writeable(vm_page_t m,uint16_t bits)5625 vm_page_assert_pga_writeable(vm_page_t m, uint16_t bits)
5626 {
5627
5628 if ((bits & PGA_WRITEABLE) == 0)
5629 return;
5630
5631 /*
5632 * The PGA_WRITEABLE flag can only be set if the page is
5633 * managed, is exclusively busied or the object is locked.
5634 * Currently, this flag is only set by pmap_enter().
5635 */
5636 KASSERT((m->oflags & VPO_UNMANAGED) == 0,
5637 ("PGA_WRITEABLE on unmanaged page"));
5638 if (!vm_page_xbusied(m))
5639 VM_OBJECT_ASSERT_BUSY(m->object);
5640 }
5641 #endif
5642
5643 #include "opt_ddb.h"
5644 #ifdef DDB
5645 #include <sys/kernel.h>
5646
5647 #include <ddb/ddb.h>
5648
DB_SHOW_COMMAND_FLAGS(page,vm_page_print_page_info,DB_CMD_MEMSAFE)5649 DB_SHOW_COMMAND_FLAGS(page, vm_page_print_page_info, DB_CMD_MEMSAFE)
5650 {
5651
5652 db_printf("vm_cnt.v_free_count: %d\n", vm_free_count());
5653 db_printf("vm_cnt.v_inactive_count: %d\n", vm_inactive_count());
5654 db_printf("vm_cnt.v_active_count: %d\n", vm_active_count());
5655 db_printf("vm_cnt.v_laundry_count: %d\n", vm_laundry_count());
5656 db_printf("vm_cnt.v_wire_count: %d\n", vm_wire_count());
5657 db_printf("vm_cnt.v_free_reserved: %d\n", vm_cnt.v_free_reserved);
5658 db_printf("vm_cnt.v_free_min: %d\n", vm_cnt.v_free_min);
5659 db_printf("vm_cnt.v_free_target: %d\n", vm_cnt.v_free_target);
5660 db_printf("vm_cnt.v_inactive_target: %d\n", vm_cnt.v_inactive_target);
5661 }
5662
DB_SHOW_COMMAND_FLAGS(pageq,vm_page_print_pageq_info,DB_CMD_MEMSAFE)5663 DB_SHOW_COMMAND_FLAGS(pageq, vm_page_print_pageq_info, DB_CMD_MEMSAFE)
5664 {
5665 int dom;
5666
5667 db_printf("pq_free %d\n", vm_free_count());
5668 for (dom = 0; dom < vm_ndomains; dom++) {
5669 db_printf(
5670 "dom %d page_cnt %d free %d pq_act %d pq_inact %d pq_laund %d pq_unsw %d\n",
5671 dom,
5672 vm_dom[dom].vmd_page_count,
5673 vm_dom[dom].vmd_free_count,
5674 vm_dom[dom].vmd_pagequeues[PQ_ACTIVE].pq_cnt,
5675 vm_dom[dom].vmd_pagequeues[PQ_INACTIVE].pq_cnt,
5676 vm_dom[dom].vmd_pagequeues[PQ_LAUNDRY].pq_cnt,
5677 vm_dom[dom].vmd_pagequeues[PQ_UNSWAPPABLE].pq_cnt);
5678 }
5679 }
5680
DB_SHOW_COMMAND(pginfo,vm_page_print_pginfo)5681 DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo)
5682 {
5683 vm_page_t m;
5684 boolean_t phys, virt;
5685
5686 if (!have_addr) {
5687 db_printf("show pginfo addr\n");
5688 return;
5689 }
5690
5691 phys = strchr(modif, 'p') != NULL;
5692 virt = strchr(modif, 'v') != NULL;
5693 if (virt)
5694 m = PHYS_TO_VM_PAGE(pmap_kextract(addr));
5695 else if (phys)
5696 m = PHYS_TO_VM_PAGE(addr);
5697 else
5698 m = (vm_page_t)addr;
5699 db_printf(
5700 "page %p obj %p pidx 0x%jx phys 0x%jx q %d ref 0x%x\n"
5701 " af 0x%x of 0x%x f 0x%x act %d busy %x valid 0x%x dirty 0x%x\n",
5702 m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr,
5703 m->a.queue, m->ref_count, m->a.flags, m->oflags,
5704 m->flags, m->a.act_count, m->busy_lock, m->valid, m->dirty);
5705 }
5706 #endif /* DDB */
5707