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_DOMAIN(vm_phys_domain(pa));
337 vm_domain_free_lock(vmd);
338 found = vm_phys_unfree_page(pa);
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,int pool)500 vm_page_init_page(vm_page_t m, vm_paddr_t pa, int segind, int pool)
501 {
502 m->object = NULL;
503 m->ref_count = 0;
504 m->busy_lock = VPB_FREED;
505 m->flags = m->a.flags = 0;
506 m->phys_addr = pa;
507 m->a.queue = PQ_NONE;
508 m->psind = 0;
509 m->segind = segind;
510 m->order = VM_NFREEORDER;
511 m->pool = pool;
512 m->valid = m->dirty = 0;
513 pmap_page_init(m);
514 }
515
516 #ifndef PMAP_HAS_PAGE_ARRAY
517 static vm_paddr_t
vm_page_array_alloc(vm_offset_t * vaddr,vm_paddr_t end,vm_paddr_t page_range)518 vm_page_array_alloc(vm_offset_t *vaddr, vm_paddr_t end, vm_paddr_t page_range)
519 {
520 vm_paddr_t new_end;
521
522 /*
523 * Reserve an unmapped guard page to trap access to vm_page_array[-1].
524 * However, because this page is allocated from KVM, out-of-bounds
525 * accesses using the direct map will not be trapped.
526 */
527 *vaddr += PAGE_SIZE;
528
529 /*
530 * Allocate physical memory for the page structures, and map it.
531 */
532 new_end = trunc_page(end - page_range * sizeof(struct vm_page));
533 vm_page_array = (vm_page_t)pmap_map(vaddr, new_end, end,
534 VM_PROT_READ | VM_PROT_WRITE);
535 vm_page_array_size = page_range;
536
537 return (new_end);
538 }
539 #endif
540
541 /*
542 * vm_page_startup:
543 *
544 * Initializes the resident memory module. Allocates physical memory for
545 * bootstrapping UMA and some data structures that are used to manage
546 * physical pages. Initializes these structures, and populates the free
547 * page queues.
548 */
549 vm_offset_t
vm_page_startup(vm_offset_t vaddr)550 vm_page_startup(vm_offset_t vaddr)
551 {
552 struct vm_phys_seg *seg;
553 struct vm_domain *vmd;
554 vm_page_t m;
555 char *list, *listend;
556 vm_paddr_t end, high_avail, low_avail, new_end, size;
557 vm_paddr_t page_range __unused;
558 vm_paddr_t last_pa, pa, startp, endp;
559 u_long pagecount;
560 #if MINIDUMP_PAGE_TRACKING
561 u_long vm_page_dump_size;
562 #endif
563 int biggestone, i, segind;
564 #ifdef WITNESS
565 vm_offset_t mapped;
566 int witness_size;
567 #endif
568 #if defined(__i386__) && defined(VM_PHYSSEG_DENSE)
569 long ii;
570 #endif
571 #ifdef VM_FREEPOOL_LAZYINIT
572 int lazyinit;
573 #endif
574
575 vaddr = round_page(vaddr);
576
577 vm_phys_early_startup();
578 biggestone = vm_phys_avail_largest();
579 end = phys_avail[biggestone+1];
580
581 /*
582 * Initialize the page and queue locks.
583 */
584 mtx_init(&vm_domainset_lock, "vm domainset lock", NULL, MTX_DEF);
585 for (i = 0; i < PA_LOCK_COUNT; i++)
586 mtx_init(&pa_lock[i], "vm page", NULL, MTX_DEF);
587 for (i = 0; i < vm_ndomains; i++)
588 vm_page_domain_init(i);
589
590 new_end = end;
591 #ifdef WITNESS
592 witness_size = round_page(witness_startup_count());
593 new_end -= witness_size;
594 mapped = pmap_map(&vaddr, new_end, new_end + witness_size,
595 VM_PROT_READ | VM_PROT_WRITE);
596 bzero((void *)mapped, witness_size);
597 witness_startup((void *)mapped);
598 #endif
599
600 #if MINIDUMP_PAGE_TRACKING
601 /*
602 * Allocate a bitmap to indicate that a random physical page
603 * needs to be included in a minidump.
604 *
605 * The amd64 port needs this to indicate which direct map pages
606 * need to be dumped, via calls to dump_add_page()/dump_drop_page().
607 *
608 * However, i386 still needs this workspace internally within the
609 * minidump code. In theory, they are not needed on i386, but are
610 * included should the sf_buf code decide to use them.
611 */
612 last_pa = 0;
613 vm_page_dump_pages = 0;
614 for (i = 0; dump_avail[i + 1] != 0; i += 2) {
615 vm_page_dump_pages += howmany(dump_avail[i + 1], PAGE_SIZE) -
616 dump_avail[i] / PAGE_SIZE;
617 if (dump_avail[i + 1] > last_pa)
618 last_pa = dump_avail[i + 1];
619 }
620 vm_page_dump_size = round_page(BITSET_SIZE(vm_page_dump_pages));
621 new_end -= vm_page_dump_size;
622 vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end,
623 new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE);
624 bzero((void *)vm_page_dump, vm_page_dump_size);
625 #if MINIDUMP_STARTUP_PAGE_TRACKING
626 /*
627 * Include the UMA bootstrap pages, witness pages and vm_page_dump
628 * in a crash dump. When pmap_map() uses the direct map, they are
629 * not automatically included.
630 */
631 for (pa = new_end; pa < end; pa += PAGE_SIZE)
632 dump_add_page(pa);
633 #endif
634 #else
635 (void)last_pa;
636 #endif
637 phys_avail[biggestone + 1] = new_end;
638 #ifdef __amd64__
639 /*
640 * Request that the physical pages underlying the message buffer be
641 * included in a crash dump. Since the message buffer is accessed
642 * through the direct map, they are not automatically included.
643 */
644 pa = DMAP_TO_PHYS((vm_offset_t)msgbufp->msg_ptr);
645 last_pa = pa + round_page(msgbufsize);
646 while (pa < last_pa) {
647 dump_add_page(pa);
648 pa += PAGE_SIZE;
649 }
650 #endif
651 /*
652 * Compute the number of pages of memory that will be available for
653 * use, taking into account the overhead of a page structure per page.
654 * In other words, solve
655 * "available physical memory" - round_page(page_range *
656 * sizeof(struct vm_page)) = page_range * PAGE_SIZE
657 * for page_range.
658 */
659 low_avail = phys_avail[0];
660 high_avail = phys_avail[1];
661 for (i = 0; i < vm_phys_nsegs; i++) {
662 if (vm_phys_segs[i].start < low_avail)
663 low_avail = vm_phys_segs[i].start;
664 if (vm_phys_segs[i].end > high_avail)
665 high_avail = vm_phys_segs[i].end;
666 }
667 /* Skip the first chunk. It is already accounted for. */
668 for (i = 2; phys_avail[i + 1] != 0; i += 2) {
669 if (phys_avail[i] < low_avail)
670 low_avail = phys_avail[i];
671 if (phys_avail[i + 1] > high_avail)
672 high_avail = phys_avail[i + 1];
673 }
674 first_page = low_avail / PAGE_SIZE;
675 #ifdef VM_PHYSSEG_SPARSE
676 size = 0;
677 for (i = 0; i < vm_phys_nsegs; i++)
678 size += vm_phys_segs[i].end - vm_phys_segs[i].start;
679 for (i = 0; phys_avail[i + 1] != 0; i += 2)
680 size += phys_avail[i + 1] - phys_avail[i];
681 #elif defined(VM_PHYSSEG_DENSE)
682 size = high_avail - low_avail;
683 #else
684 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined."
685 #endif
686
687 #ifdef PMAP_HAS_PAGE_ARRAY
688 pmap_page_array_startup(size / PAGE_SIZE);
689 biggestone = vm_phys_avail_largest();
690 end = new_end = phys_avail[biggestone + 1];
691 #else
692 #ifdef VM_PHYSSEG_DENSE
693 /*
694 * In the VM_PHYSSEG_DENSE case, the number of pages can account for
695 * the overhead of a page structure per page only if vm_page_array is
696 * allocated from the last physical memory chunk. Otherwise, we must
697 * allocate page structures representing the physical memory
698 * underlying vm_page_array, even though they will not be used.
699 */
700 if (new_end != high_avail)
701 page_range = size / PAGE_SIZE;
702 else
703 #endif
704 {
705 page_range = size / (PAGE_SIZE + sizeof(struct vm_page));
706
707 /*
708 * If the partial bytes remaining are large enough for
709 * a page (PAGE_SIZE) without a corresponding
710 * 'struct vm_page', then new_end will contain an
711 * extra page after subtracting the length of the VM
712 * page array. Compensate by subtracting an extra
713 * page from new_end.
714 */
715 if (size % (PAGE_SIZE + sizeof(struct vm_page)) >= PAGE_SIZE) {
716 if (new_end == high_avail)
717 high_avail -= PAGE_SIZE;
718 new_end -= PAGE_SIZE;
719 }
720 }
721 end = new_end;
722 new_end = vm_page_array_alloc(&vaddr, end, page_range);
723 #endif
724
725 #if VM_NRESERVLEVEL > 0
726 /*
727 * Allocate physical memory for the reservation management system's
728 * data structures, and map it.
729 */
730 new_end = vm_reserv_startup(&vaddr, new_end);
731 #endif
732 #if MINIDUMP_PAGE_TRACKING && MINIDUMP_STARTUP_PAGE_TRACKING
733 /*
734 * Include vm_page_array and vm_reserv_array in a crash dump.
735 */
736 for (pa = new_end; pa < end; pa += PAGE_SIZE)
737 dump_add_page(pa);
738 #endif
739 phys_avail[biggestone + 1] = new_end;
740
741 /*
742 * Add physical memory segments corresponding to the available
743 * physical pages.
744 */
745 for (i = 0; phys_avail[i + 1] != 0; i += 2)
746 if (vm_phys_avail_size(i) != 0)
747 vm_phys_add_seg(phys_avail[i], phys_avail[i + 1]);
748
749 /*
750 * Initialize the physical memory allocator.
751 */
752 vm_phys_init();
753
754 #ifdef VM_FREEPOOL_LAZYINIT
755 lazyinit = 1;
756 TUNABLE_INT_FETCH("debug.vm.lazy_page_init", &lazyinit);
757 #endif
758
759 /*
760 * Initialize the page structures and add every available page to the
761 * physical memory allocator's free lists.
762 */
763 #if defined(__i386__) && defined(VM_PHYSSEG_DENSE)
764 for (ii = 0; ii < vm_page_array_size; ii++) {
765 m = &vm_page_array[ii];
766 vm_page_init_page(m, (first_page + ii) << PAGE_SHIFT, 0,
767 VM_FREEPOOL_DEFAULT);
768 m->flags = PG_FICTITIOUS;
769 }
770 #endif
771 vm_cnt.v_page_count = 0;
772 for (segind = 0; segind < vm_phys_nsegs; segind++) {
773 seg = &vm_phys_segs[segind];
774
775 /*
776 * If lazy vm_page initialization is not enabled, simply
777 * initialize all of the pages in the segment. Otherwise, we
778 * only initialize:
779 * 1. Pages not covered by phys_avail[], since they might be
780 * freed to the allocator at some future point, e.g., by
781 * kmem_bootstrap_free().
782 * 2. The first page of each run of free pages handed to the
783 * vm_phys allocator, which in turn defers initialization
784 * of pages until they are needed.
785 * This avoids blocking the boot process for long periods, which
786 * may be relevant for VMs (which ought to boot as quickly as
787 * possible) and/or systems with large amounts of physical
788 * memory.
789 */
790 #ifdef VM_FREEPOOL_LAZYINIT
791 if (lazyinit) {
792 startp = seg->start;
793 for (i = 0; phys_avail[i + 1] != 0; i += 2) {
794 if (startp >= seg->end)
795 break;
796
797 if (phys_avail[i + 1] < startp)
798 continue;
799 if (phys_avail[i] <= startp) {
800 startp = phys_avail[i + 1];
801 continue;
802 }
803
804 m = vm_phys_seg_paddr_to_vm_page(seg, startp);
805 for (endp = MIN(phys_avail[i], seg->end);
806 startp < endp; startp += PAGE_SIZE, m++) {
807 vm_page_init_page(m, startp, segind,
808 VM_FREEPOOL_DEFAULT);
809 }
810 }
811 } else
812 #endif
813 for (m = seg->first_page, pa = seg->start;
814 pa < seg->end; m++, pa += PAGE_SIZE) {
815 vm_page_init_page(m, pa, segind,
816 VM_FREEPOOL_DEFAULT);
817 }
818
819 /*
820 * Add the segment's pages that are covered by one of
821 * phys_avail's ranges to the free lists.
822 */
823 for (i = 0; phys_avail[i + 1] != 0; i += 2) {
824 if (seg->end <= phys_avail[i] ||
825 seg->start >= phys_avail[i + 1])
826 continue;
827
828 startp = MAX(seg->start, phys_avail[i]);
829 endp = MIN(seg->end, phys_avail[i + 1]);
830 pagecount = (u_long)atop(endp - startp);
831 if (pagecount == 0)
832 continue;
833
834 m = vm_phys_seg_paddr_to_vm_page(seg, startp);
835 #ifdef VM_FREEPOOL_LAZYINIT
836 if (lazyinit) {
837 vm_page_init_page(m, startp, segind,
838 VM_FREEPOOL_LAZYINIT);
839 }
840 #endif
841 vmd = VM_DOMAIN(seg->domain);
842 vm_domain_free_lock(vmd);
843 vm_phys_enqueue_contig(m, pagecount);
844 vm_domain_free_unlock(vmd);
845 vm_domain_freecnt_inc(vmd, pagecount);
846 vm_cnt.v_page_count += (u_int)pagecount;
847 vmd->vmd_page_count += (u_int)pagecount;
848 vmd->vmd_segs |= 1UL << segind;
849 }
850 }
851
852 /*
853 * Remove blacklisted pages from the physical memory allocator.
854 */
855 TAILQ_INIT(&blacklist_head);
856 vm_page_blacklist_load(&list, &listend);
857 vm_page_blacklist_check(list, listend);
858
859 list = kern_getenv("vm.blacklist");
860 vm_page_blacklist_check(list, NULL);
861
862 freeenv(list);
863 #if VM_NRESERVLEVEL > 0
864 /*
865 * Initialize the reservation management system.
866 */
867 vm_reserv_init();
868 #endif
869
870 return (vaddr);
871 }
872
873 void
vm_page_reference(vm_page_t m)874 vm_page_reference(vm_page_t m)
875 {
876
877 vm_page_aflag_set(m, PGA_REFERENCED);
878 }
879
880 /*
881 * vm_page_trybusy
882 *
883 * Helper routine for grab functions to trylock busy.
884 *
885 * Returns true on success and false on failure.
886 */
887 static bool
vm_page_trybusy(vm_page_t m,int allocflags)888 vm_page_trybusy(vm_page_t m, int allocflags)
889 {
890
891 if ((allocflags & (VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY)) != 0)
892 return (vm_page_trysbusy(m));
893 else
894 return (vm_page_tryxbusy(m));
895 }
896
897 /*
898 * vm_page_tryacquire
899 *
900 * Helper routine for grab functions to trylock busy and wire.
901 *
902 * Returns true on success and false on failure.
903 */
904 static inline bool
vm_page_tryacquire(vm_page_t m,int allocflags)905 vm_page_tryacquire(vm_page_t m, int allocflags)
906 {
907 bool locked;
908
909 locked = vm_page_trybusy(m, allocflags);
910 if (locked && (allocflags & VM_ALLOC_WIRED) != 0)
911 vm_page_wire(m);
912 return (locked);
913 }
914
915 /*
916 * vm_page_busy_acquire:
917 *
918 * Acquire the busy lock as described by VM_ALLOC_* flags. Will loop
919 * and drop the object lock if necessary.
920 */
921 bool
vm_page_busy_acquire(vm_page_t m,int allocflags)922 vm_page_busy_acquire(vm_page_t m, int allocflags)
923 {
924 vm_object_t obj;
925 bool locked;
926
927 /*
928 * The page-specific object must be cached because page
929 * identity can change during the sleep, causing the
930 * re-lock of a different object.
931 * It is assumed that a reference to the object is already
932 * held by the callers.
933 */
934 obj = atomic_load_ptr(&m->object);
935 for (;;) {
936 if (vm_page_tryacquire(m, allocflags))
937 return (true);
938 if ((allocflags & VM_ALLOC_NOWAIT) != 0)
939 return (false);
940 if (obj != NULL)
941 locked = VM_OBJECT_WOWNED(obj);
942 else
943 locked = false;
944 MPASS(locked || vm_page_wired(m));
945 if (_vm_page_busy_sleep(obj, m, m->pindex, "vmpba", allocflags,
946 locked) && locked)
947 VM_OBJECT_WLOCK(obj);
948 if ((allocflags & VM_ALLOC_WAITFAIL) != 0)
949 return (false);
950 KASSERT(m->object == obj || m->object == NULL,
951 ("vm_page_busy_acquire: page %p does not belong to %p",
952 m, obj));
953 }
954 }
955
956 /*
957 * vm_page_busy_downgrade:
958 *
959 * Downgrade an exclusive busy page into a single shared busy page.
960 */
961 void
vm_page_busy_downgrade(vm_page_t m)962 vm_page_busy_downgrade(vm_page_t m)
963 {
964 u_int x;
965
966 vm_page_assert_xbusied(m);
967
968 x = vm_page_busy_fetch(m);
969 for (;;) {
970 if (atomic_fcmpset_rel_int(&m->busy_lock,
971 &x, VPB_SHARERS_WORD(1)))
972 break;
973 }
974 if ((x & VPB_BIT_WAITERS) != 0)
975 wakeup(m);
976 }
977
978 /*
979 *
980 * vm_page_busy_tryupgrade:
981 *
982 * Attempt to upgrade a single shared busy into an exclusive busy.
983 */
984 int
vm_page_busy_tryupgrade(vm_page_t m)985 vm_page_busy_tryupgrade(vm_page_t m)
986 {
987 u_int ce, x;
988
989 vm_page_assert_sbusied(m);
990
991 x = vm_page_busy_fetch(m);
992 ce = VPB_CURTHREAD_EXCLUSIVE;
993 for (;;) {
994 if (VPB_SHARERS(x) > 1)
995 return (0);
996 KASSERT((x & ~VPB_BIT_WAITERS) == VPB_SHARERS_WORD(1),
997 ("vm_page_busy_tryupgrade: invalid lock state"));
998 if (!atomic_fcmpset_acq_int(&m->busy_lock, &x,
999 ce | (x & VPB_BIT_WAITERS)))
1000 continue;
1001 return (1);
1002 }
1003 }
1004
1005 /*
1006 * vm_page_sbusied:
1007 *
1008 * Return a positive value if the page is shared busied, 0 otherwise.
1009 */
1010 int
vm_page_sbusied(vm_page_t m)1011 vm_page_sbusied(vm_page_t m)
1012 {
1013 u_int x;
1014
1015 x = vm_page_busy_fetch(m);
1016 return ((x & VPB_BIT_SHARED) != 0 && x != VPB_UNBUSIED);
1017 }
1018
1019 /*
1020 * vm_page_sunbusy:
1021 *
1022 * Shared unbusy a page.
1023 */
1024 void
vm_page_sunbusy(vm_page_t m)1025 vm_page_sunbusy(vm_page_t m)
1026 {
1027 u_int x;
1028
1029 vm_page_assert_sbusied(m);
1030
1031 x = vm_page_busy_fetch(m);
1032 for (;;) {
1033 KASSERT(x != VPB_FREED,
1034 ("vm_page_sunbusy: Unlocking freed page."));
1035 if (VPB_SHARERS(x) > 1) {
1036 if (atomic_fcmpset_int(&m->busy_lock, &x,
1037 x - VPB_ONE_SHARER))
1038 break;
1039 continue;
1040 }
1041 KASSERT((x & ~VPB_BIT_WAITERS) == VPB_SHARERS_WORD(1),
1042 ("vm_page_sunbusy: invalid lock state"));
1043 if (!atomic_fcmpset_rel_int(&m->busy_lock, &x, VPB_UNBUSIED))
1044 continue;
1045 if ((x & VPB_BIT_WAITERS) == 0)
1046 break;
1047 wakeup(m);
1048 break;
1049 }
1050 }
1051
1052 /*
1053 * vm_page_busy_sleep:
1054 *
1055 * Sleep if the page is busy, using the page pointer as wchan.
1056 * This is used to implement the hard-path of the busying mechanism.
1057 *
1058 * If VM_ALLOC_IGN_SBUSY is specified in allocflags, the function
1059 * will not sleep if the page is shared-busy.
1060 *
1061 * The object lock must be held on entry.
1062 *
1063 * Returns true if it slept and dropped the object lock, or false
1064 * if there was no sleep and the lock is still held.
1065 */
1066 bool
vm_page_busy_sleep(vm_page_t m,const char * wmesg,int allocflags)1067 vm_page_busy_sleep(vm_page_t m, const char *wmesg, int allocflags)
1068 {
1069 vm_object_t obj;
1070
1071 obj = m->object;
1072 VM_OBJECT_ASSERT_LOCKED(obj);
1073
1074 return (_vm_page_busy_sleep(obj, m, m->pindex, wmesg, allocflags,
1075 true));
1076 }
1077
1078 /*
1079 * vm_page_busy_sleep_unlocked:
1080 *
1081 * Sleep if the page is busy, using the page pointer as wchan.
1082 * This is used to implement the hard-path of busying mechanism.
1083 *
1084 * If VM_ALLOC_IGN_SBUSY is specified in allocflags, the function
1085 * will not sleep if the page is shared-busy.
1086 *
1087 * The object lock must not be held on entry. The operation will
1088 * return if the page changes identity.
1089 */
1090 void
vm_page_busy_sleep_unlocked(vm_object_t obj,vm_page_t m,vm_pindex_t pindex,const char * wmesg,int allocflags)1091 vm_page_busy_sleep_unlocked(vm_object_t obj, vm_page_t m, vm_pindex_t pindex,
1092 const char *wmesg, int allocflags)
1093 {
1094 VM_OBJECT_ASSERT_UNLOCKED(obj);
1095
1096 (void)_vm_page_busy_sleep(obj, m, pindex, wmesg, allocflags, false);
1097 }
1098
1099 /*
1100 * _vm_page_busy_sleep:
1101 *
1102 * Internal busy sleep function. Verifies the page identity and
1103 * lockstate against parameters. Returns true if it sleeps and
1104 * false otherwise.
1105 *
1106 * allocflags uses VM_ALLOC_* flags to specify the lock required.
1107 *
1108 * If locked is true the lock will be dropped for any true returns
1109 * and held for any false returns.
1110 */
1111 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)1112 _vm_page_busy_sleep(vm_object_t obj, vm_page_t m, vm_pindex_t pindex,
1113 const char *wmesg, int allocflags, bool locked)
1114 {
1115 bool xsleep;
1116 u_int x;
1117
1118 /*
1119 * If the object is busy we must wait for that to drain to zero
1120 * before trying the page again.
1121 */
1122 if (obj != NULL && vm_object_busied(obj)) {
1123 if (locked)
1124 VM_OBJECT_DROP(obj);
1125 vm_object_busy_wait(obj, wmesg);
1126 return (true);
1127 }
1128
1129 if (!vm_page_busied(m))
1130 return (false);
1131
1132 xsleep = (allocflags & (VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY)) != 0;
1133 sleepq_lock(m);
1134 x = vm_page_busy_fetch(m);
1135 do {
1136 /*
1137 * If the page changes objects or becomes unlocked we can
1138 * simply return.
1139 */
1140 if (x == VPB_UNBUSIED ||
1141 (xsleep && (x & VPB_BIT_SHARED) != 0) ||
1142 m->object != obj || m->pindex != pindex) {
1143 sleepq_release(m);
1144 return (false);
1145 }
1146 if ((x & VPB_BIT_WAITERS) != 0)
1147 break;
1148 } while (!atomic_fcmpset_int(&m->busy_lock, &x, x | VPB_BIT_WAITERS));
1149 if (locked)
1150 VM_OBJECT_DROP(obj);
1151 DROP_GIANT();
1152 sleepq_add(m, NULL, wmesg, 0, 0);
1153 sleepq_wait(m, PVM);
1154 PICKUP_GIANT();
1155 return (true);
1156 }
1157
1158 /*
1159 * vm_page_trysbusy:
1160 *
1161 * Try to shared busy a page.
1162 * If the operation succeeds 1 is returned otherwise 0.
1163 * The operation never sleeps.
1164 */
1165 int
vm_page_trysbusy(vm_page_t m)1166 vm_page_trysbusy(vm_page_t m)
1167 {
1168 vm_object_t obj;
1169 u_int x;
1170
1171 obj = m->object;
1172 x = vm_page_busy_fetch(m);
1173 for (;;) {
1174 if ((x & VPB_BIT_SHARED) == 0)
1175 return (0);
1176 /*
1177 * Reduce the window for transient busies that will trigger
1178 * false negatives in vm_page_ps_test().
1179 */
1180 if (obj != NULL && vm_object_busied(obj))
1181 return (0);
1182 if (atomic_fcmpset_acq_int(&m->busy_lock, &x,
1183 x + VPB_ONE_SHARER))
1184 break;
1185 }
1186
1187 /* Refetch the object now that we're guaranteed that it is stable. */
1188 obj = m->object;
1189 if (obj != NULL && vm_object_busied(obj)) {
1190 vm_page_sunbusy(m);
1191 return (0);
1192 }
1193 return (1);
1194 }
1195
1196 /*
1197 * vm_page_tryxbusy:
1198 *
1199 * Try to exclusive busy a page.
1200 * If the operation succeeds 1 is returned otherwise 0.
1201 * The operation never sleeps.
1202 */
1203 int
vm_page_tryxbusy(vm_page_t m)1204 vm_page_tryxbusy(vm_page_t m)
1205 {
1206 vm_object_t obj;
1207
1208 if (atomic_cmpset_acq_int(&m->busy_lock, VPB_UNBUSIED,
1209 VPB_CURTHREAD_EXCLUSIVE) == 0)
1210 return (0);
1211
1212 obj = m->object;
1213 if (obj != NULL && vm_object_busied(obj)) {
1214 vm_page_xunbusy(m);
1215 return (0);
1216 }
1217 return (1);
1218 }
1219
1220 static void
vm_page_xunbusy_hard_tail(vm_page_t m)1221 vm_page_xunbusy_hard_tail(vm_page_t m)
1222 {
1223 atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED);
1224 /* Wake the waiter. */
1225 wakeup(m);
1226 }
1227
1228 /*
1229 * vm_page_xunbusy_hard:
1230 *
1231 * Called when unbusy has failed because there is a waiter.
1232 */
1233 void
vm_page_xunbusy_hard(vm_page_t m)1234 vm_page_xunbusy_hard(vm_page_t m)
1235 {
1236 vm_page_assert_xbusied(m);
1237 vm_page_xunbusy_hard_tail(m);
1238 }
1239
1240 void
vm_page_xunbusy_hard_unchecked(vm_page_t m)1241 vm_page_xunbusy_hard_unchecked(vm_page_t m)
1242 {
1243 vm_page_assert_xbusied_unchecked(m);
1244 vm_page_xunbusy_hard_tail(m);
1245 }
1246
1247 static void
vm_page_busy_free(vm_page_t m)1248 vm_page_busy_free(vm_page_t m)
1249 {
1250 u_int x;
1251
1252 atomic_thread_fence_rel();
1253 x = atomic_swap_int(&m->busy_lock, VPB_FREED);
1254 if ((x & VPB_BIT_WAITERS) != 0)
1255 wakeup(m);
1256 }
1257
1258 /*
1259 * vm_page_unhold_pages:
1260 *
1261 * Unhold each of the pages that is referenced by the given array.
1262 */
1263 void
vm_page_unhold_pages(vm_page_t * ma,int count)1264 vm_page_unhold_pages(vm_page_t *ma, int count)
1265 {
1266
1267 for (; count != 0; count--) {
1268 vm_page_unwire(*ma, PQ_ACTIVE);
1269 ma++;
1270 }
1271 }
1272
1273 vm_page_t
PHYS_TO_VM_PAGE(vm_paddr_t pa)1274 PHYS_TO_VM_PAGE(vm_paddr_t pa)
1275 {
1276 vm_page_t m;
1277
1278 #ifdef VM_PHYSSEG_SPARSE
1279 m = vm_phys_paddr_to_vm_page(pa);
1280 if (m == NULL)
1281 m = vm_phys_fictitious_to_vm_page(pa);
1282 return (m);
1283 #elif defined(VM_PHYSSEG_DENSE)
1284 long pi;
1285
1286 pi = atop(pa);
1287 if (pi >= first_page && (pi - first_page) < vm_page_array_size) {
1288 m = &vm_page_array[pi - first_page];
1289 return (m);
1290 }
1291 return (vm_phys_fictitious_to_vm_page(pa));
1292 #else
1293 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined."
1294 #endif
1295 }
1296
1297 /*
1298 * vm_page_getfake:
1299 *
1300 * Create a fictitious page with the specified physical address and
1301 * memory attribute. The memory attribute is the only the machine-
1302 * dependent aspect of a fictitious page that must be initialized.
1303 */
1304 vm_page_t
vm_page_getfake(vm_paddr_t paddr,vm_memattr_t memattr)1305 vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr)
1306 {
1307 vm_page_t m;
1308
1309 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO);
1310 vm_page_initfake(m, paddr, memattr);
1311 return (m);
1312 }
1313
1314 void
vm_page_initfake(vm_page_t m,vm_paddr_t paddr,vm_memattr_t memattr)1315 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr)
1316 {
1317
1318 if ((m->flags & PG_FICTITIOUS) != 0) {
1319 /*
1320 * The page's memattr might have changed since the
1321 * previous initialization. Update the pmap to the
1322 * new memattr.
1323 */
1324 goto memattr;
1325 }
1326 m->phys_addr = paddr;
1327 m->a.queue = PQ_NONE;
1328 /* Fictitious pages don't use "segind". */
1329 m->flags = PG_FICTITIOUS;
1330 /* Fictitious pages don't use "order" or "pool". */
1331 m->oflags = VPO_UNMANAGED;
1332 m->busy_lock = VPB_CURTHREAD_EXCLUSIVE;
1333 /* Fictitious pages are unevictable. */
1334 m->ref_count = 1;
1335 pmap_page_init(m);
1336 memattr:
1337 pmap_page_set_memattr(m, memattr);
1338 }
1339
1340 /*
1341 * vm_page_putfake:
1342 *
1343 * Release a fictitious page.
1344 */
1345 void
vm_page_putfake(vm_page_t m)1346 vm_page_putfake(vm_page_t m)
1347 {
1348
1349 KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m));
1350 KASSERT((m->flags & PG_FICTITIOUS) != 0,
1351 ("vm_page_putfake: bad page %p", m));
1352 vm_page_assert_xbusied(m);
1353 vm_page_busy_free(m);
1354 uma_zfree(fakepg_zone, m);
1355 }
1356
1357 /*
1358 * vm_page_updatefake:
1359 *
1360 * Update the given fictitious page to the specified physical address and
1361 * memory attribute.
1362 */
1363 void
vm_page_updatefake(vm_page_t m,vm_paddr_t paddr,vm_memattr_t memattr)1364 vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr)
1365 {
1366
1367 KASSERT((m->flags & PG_FICTITIOUS) != 0,
1368 ("vm_page_updatefake: bad page %p", m));
1369 m->phys_addr = paddr;
1370 pmap_page_set_memattr(m, memattr);
1371 }
1372
1373 /*
1374 * vm_page_free:
1375 *
1376 * Free a page.
1377 */
1378 void
vm_page_free(vm_page_t m)1379 vm_page_free(vm_page_t m)
1380 {
1381
1382 m->flags &= ~PG_ZERO;
1383 vm_page_free_toq(m);
1384 }
1385
1386 /*
1387 * vm_page_free_zero:
1388 *
1389 * Free a page to the zerod-pages queue
1390 */
1391 void
vm_page_free_zero(vm_page_t m)1392 vm_page_free_zero(vm_page_t m)
1393 {
1394
1395 m->flags |= PG_ZERO;
1396 vm_page_free_toq(m);
1397 }
1398
1399 /*
1400 * Unbusy and handle the page queueing for a page from a getpages request that
1401 * was optionally read ahead or behind.
1402 */
1403 void
vm_page_readahead_finish(vm_page_t m)1404 vm_page_readahead_finish(vm_page_t m)
1405 {
1406
1407 /* We shouldn't put invalid pages on queues. */
1408 KASSERT(!vm_page_none_valid(m), ("%s: %p is invalid", __func__, m));
1409
1410 /*
1411 * Since the page is not the actually needed one, whether it should
1412 * be activated or deactivated is not obvious. Empirical results
1413 * have shown that deactivating the page is usually the best choice,
1414 * unless the page is wanted by another thread.
1415 */
1416 if ((vm_page_busy_fetch(m) & VPB_BIT_WAITERS) != 0)
1417 vm_page_activate(m);
1418 else
1419 vm_page_deactivate(m);
1420 vm_page_xunbusy_unchecked(m);
1421 }
1422
1423 /*
1424 * Destroy the identity of an invalid page and free it if possible.
1425 * This is intended to be used when reading a page from backing store fails.
1426 */
1427 void
vm_page_free_invalid(vm_page_t m)1428 vm_page_free_invalid(vm_page_t m)
1429 {
1430
1431 KASSERT(vm_page_none_valid(m), ("page %p is valid", m));
1432 KASSERT(!pmap_page_is_mapped(m), ("page %p is mapped", m));
1433 KASSERT(m->object != NULL, ("page %p has no object", m));
1434 VM_OBJECT_ASSERT_WLOCKED(m->object);
1435
1436 /*
1437 * We may be attempting to free the page as part of the handling for an
1438 * I/O error, in which case the page was xbusied by a different thread.
1439 */
1440 vm_page_xbusy_claim(m);
1441
1442 /*
1443 * If someone has wired this page while the object lock
1444 * was not held, then the thread that unwires is responsible
1445 * for freeing the page. Otherwise just free the page now.
1446 * The wire count of this unmapped page cannot change while
1447 * we have the page xbusy and the page's object wlocked.
1448 */
1449 if (vm_page_remove(m))
1450 vm_page_free(m);
1451 }
1452
1453 /*
1454 * vm_page_dirty_KBI: [ internal use only ]
1455 *
1456 * Set all bits in the page's dirty field.
1457 *
1458 * The object containing the specified page must be locked if the
1459 * call is made from the machine-independent layer.
1460 *
1461 * See vm_page_clear_dirty_mask().
1462 *
1463 * This function should only be called by vm_page_dirty().
1464 */
1465 void
vm_page_dirty_KBI(vm_page_t m)1466 vm_page_dirty_KBI(vm_page_t m)
1467 {
1468
1469 /* Refer to this operation by its public name. */
1470 KASSERT(vm_page_all_valid(m), ("vm_page_dirty: page is invalid!"));
1471 m->dirty = VM_PAGE_BITS_ALL;
1472 }
1473
1474 /*
1475 * Insert the given page into the given object at the given pindex. mpred is
1476 * used for memq linkage. From vm_page_insert, lookup is true, mpred is
1477 * initially NULL, and this procedure looks it up. From vm_page_insert_after,
1478 * lookup is false and mpred is known to the caller to be valid, and may be
1479 * NULL if this will be the page with the lowest pindex.
1480 *
1481 * The procedure is marked __always_inline to suggest to the compiler to
1482 * eliminate the lookup parameter and the associated alternate branch.
1483 */
1484 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)1485 vm_page_insert_lookup(vm_page_t m, vm_object_t object, vm_pindex_t pindex,
1486 vm_page_t mpred, bool lookup)
1487 {
1488 int error;
1489
1490 VM_OBJECT_ASSERT_WLOCKED(object);
1491 KASSERT(m->object == NULL,
1492 ("vm_page_insert: page %p already inserted", m));
1493
1494 /*
1495 * Record the object/offset pair in this page.
1496 */
1497 m->object = object;
1498 m->pindex = pindex;
1499 m->ref_count |= VPRC_OBJREF;
1500
1501 /*
1502 * Add this page to the object's radix tree, and look up mpred if
1503 * needed.
1504 */
1505 if (lookup)
1506 error = vm_radix_insert_lookup_lt(&object->rtree, m, &mpred);
1507 else
1508 error = vm_radix_insert(&object->rtree, m);
1509 if (__predict_false(error != 0)) {
1510 m->object = NULL;
1511 m->pindex = 0;
1512 m->ref_count &= ~VPRC_OBJREF;
1513 return (1);
1514 }
1515
1516 /*
1517 * Now link into the object's ordered list of backed pages.
1518 */
1519 vm_page_insert_radixdone(m, object, mpred);
1520 vm_pager_page_inserted(object, m);
1521 return (0);
1522 }
1523
1524 /*
1525 * vm_page_insert: [ internal use only ]
1526 *
1527 * Inserts the given mem entry into the object and object list.
1528 *
1529 * The object must be locked.
1530 */
1531 int
vm_page_insert(vm_page_t m,vm_object_t object,vm_pindex_t pindex)1532 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex)
1533 {
1534 return (vm_page_insert_lookup(m, object, pindex, NULL, true));
1535 }
1536
1537 /*
1538 * vm_page_insert_after:
1539 *
1540 * Inserts the page "m" into the specified object at offset "pindex".
1541 *
1542 * The page "mpred" must immediately precede the offset "pindex" within
1543 * the specified object.
1544 *
1545 * The object must be locked.
1546 */
1547 static int
vm_page_insert_after(vm_page_t m,vm_object_t object,vm_pindex_t pindex,vm_page_t mpred)1548 vm_page_insert_after(vm_page_t m, vm_object_t object, vm_pindex_t pindex,
1549 vm_page_t mpred)
1550 {
1551 return (vm_page_insert_lookup(m, object, pindex, mpred, false));
1552 }
1553
1554 /*
1555 * vm_page_insert_radixdone:
1556 *
1557 * Complete page "m" insertion into the specified object after the
1558 * radix trie hooking.
1559 *
1560 * The page "mpred" must precede the offset "m->pindex" within the
1561 * specified object.
1562 *
1563 * The object must be locked.
1564 */
1565 static void
vm_page_insert_radixdone(vm_page_t m,vm_object_t object,vm_page_t mpred)1566 vm_page_insert_radixdone(vm_page_t m, vm_object_t object, vm_page_t mpred)
1567 {
1568
1569 VM_OBJECT_ASSERT_WLOCKED(object);
1570 KASSERT(object != NULL && m->object == object,
1571 ("vm_page_insert_radixdone: page %p has inconsistent object", m));
1572 KASSERT((m->ref_count & VPRC_OBJREF) != 0,
1573 ("vm_page_insert_radixdone: page %p is missing object ref", m));
1574 if (mpred != NULL) {
1575 KASSERT(mpred->object == object,
1576 ("vm_page_insert_radixdone: object doesn't contain mpred"));
1577 KASSERT(mpred->pindex < m->pindex,
1578 ("vm_page_insert_radixdone: mpred doesn't precede pindex"));
1579 KASSERT(TAILQ_NEXT(mpred, listq) == NULL ||
1580 m->pindex < TAILQ_NEXT(mpred, listq)->pindex,
1581 ("vm_page_insert_radixdone: pindex doesn't precede msucc"));
1582 } else {
1583 KASSERT(TAILQ_EMPTY(&object->memq) ||
1584 m->pindex < TAILQ_FIRST(&object->memq)->pindex,
1585 ("vm_page_insert_radixdone: no mpred but not first page"));
1586 }
1587
1588 if (mpred != NULL)
1589 TAILQ_INSERT_AFTER(&object->memq, mpred, m, listq);
1590 else
1591 TAILQ_INSERT_HEAD(&object->memq, m, listq);
1592
1593 /*
1594 * Show that the object has one more resident page.
1595 */
1596 object->resident_page_count++;
1597
1598 /*
1599 * Hold the vnode until the last page is released.
1600 */
1601 if (object->resident_page_count == 1 && object->type == OBJT_VNODE)
1602 vhold(object->handle);
1603
1604 /*
1605 * Since we are inserting a new and possibly dirty page,
1606 * update the object's generation count.
1607 */
1608 if (pmap_page_is_write_mapped(m))
1609 vm_object_set_writeable_dirty(object);
1610 }
1611
1612 /*
1613 * Do the work to remove a page from its object. The caller is responsible for
1614 * updating the page's fields to reflect this removal.
1615 */
1616 static void
vm_page_object_remove(vm_page_t m)1617 vm_page_object_remove(vm_page_t m)
1618 {
1619 vm_object_t object;
1620 vm_page_t mrem __diagused;
1621
1622 vm_page_assert_xbusied(m);
1623 object = m->object;
1624 VM_OBJECT_ASSERT_WLOCKED(object);
1625 KASSERT((m->ref_count & VPRC_OBJREF) != 0,
1626 ("page %p is missing its object ref", m));
1627
1628 /* Deferred free of swap space. */
1629 if ((m->a.flags & PGA_SWAP_FREE) != 0)
1630 vm_pager_page_unswapped(m);
1631
1632 vm_pager_page_removed(object, m);
1633
1634 m->object = NULL;
1635 mrem = vm_radix_remove(&object->rtree, m->pindex);
1636 KASSERT(mrem == m, ("removed page %p, expected page %p", mrem, m));
1637
1638 /*
1639 * Now remove from the object's list of backed pages.
1640 */
1641 TAILQ_REMOVE(&object->memq, m, listq);
1642
1643 /*
1644 * And show that the object has one fewer resident page.
1645 */
1646 object->resident_page_count--;
1647
1648 /*
1649 * The vnode may now be recycled.
1650 */
1651 if (object->resident_page_count == 0 && object->type == OBJT_VNODE)
1652 vdrop(object->handle);
1653 }
1654
1655 /*
1656 * vm_page_remove:
1657 *
1658 * Removes the specified page from its containing object, but does not
1659 * invalidate any backing storage. Returns true if the object's reference
1660 * was the last reference to the page, and false otherwise.
1661 *
1662 * The object must be locked and the page must be exclusively busied.
1663 * The exclusive busy will be released on return. If this is not the
1664 * final ref and the caller does not hold a wire reference it may not
1665 * continue to access the page.
1666 */
1667 bool
vm_page_remove(vm_page_t m)1668 vm_page_remove(vm_page_t m)
1669 {
1670 bool dropped;
1671
1672 dropped = vm_page_remove_xbusy(m);
1673 vm_page_xunbusy(m);
1674
1675 return (dropped);
1676 }
1677
1678 /*
1679 * vm_page_remove_xbusy
1680 *
1681 * Removes the page but leaves the xbusy held. Returns true if this
1682 * removed the final ref and false otherwise.
1683 */
1684 bool
vm_page_remove_xbusy(vm_page_t m)1685 vm_page_remove_xbusy(vm_page_t m)
1686 {
1687
1688 vm_page_object_remove(m);
1689 return (vm_page_drop(m, VPRC_OBJREF) == VPRC_OBJREF);
1690 }
1691
1692 /*
1693 * vm_page_lookup:
1694 *
1695 * Returns the page associated with the object/offset
1696 * pair specified; if none is found, NULL is returned.
1697 *
1698 * The object must be locked.
1699 */
1700 vm_page_t
vm_page_lookup(vm_object_t object,vm_pindex_t pindex)1701 vm_page_lookup(vm_object_t object, vm_pindex_t pindex)
1702 {
1703
1704 VM_OBJECT_ASSERT_LOCKED(object);
1705 return (vm_radix_lookup(&object->rtree, pindex));
1706 }
1707
1708 /*
1709 * vm_page_lookup_unlocked:
1710 *
1711 * Returns the page associated with the object/offset pair specified;
1712 * if none is found, NULL is returned. The page may be no longer be
1713 * present in the object at the time that this function returns. Only
1714 * useful for opportunistic checks such as inmem().
1715 */
1716 vm_page_t
vm_page_lookup_unlocked(vm_object_t object,vm_pindex_t pindex)1717 vm_page_lookup_unlocked(vm_object_t object, vm_pindex_t pindex)
1718 {
1719
1720 return (vm_radix_lookup_unlocked(&object->rtree, pindex));
1721 }
1722
1723 /*
1724 * vm_page_relookup:
1725 *
1726 * Returns a page that must already have been busied by
1727 * the caller. Used for bogus page replacement.
1728 */
1729 vm_page_t
vm_page_relookup(vm_object_t object,vm_pindex_t pindex)1730 vm_page_relookup(vm_object_t object, vm_pindex_t pindex)
1731 {
1732 vm_page_t m;
1733
1734 m = vm_radix_lookup_unlocked(&object->rtree, pindex);
1735 KASSERT(m != NULL && (vm_page_busied(m) || vm_page_wired(m)) &&
1736 m->object == object && m->pindex == pindex,
1737 ("vm_page_relookup: Invalid page %p", m));
1738 return (m);
1739 }
1740
1741 /*
1742 * This should only be used by lockless functions for releasing transient
1743 * incorrect acquires. The page may have been freed after we acquired a
1744 * busy lock. In this case busy_lock == VPB_FREED and we have nothing
1745 * further to do.
1746 */
1747 static void
vm_page_busy_release(vm_page_t m)1748 vm_page_busy_release(vm_page_t m)
1749 {
1750 u_int x;
1751
1752 x = vm_page_busy_fetch(m);
1753 for (;;) {
1754 if (x == VPB_FREED)
1755 break;
1756 if ((x & VPB_BIT_SHARED) != 0 && VPB_SHARERS(x) > 1) {
1757 if (atomic_fcmpset_int(&m->busy_lock, &x,
1758 x - VPB_ONE_SHARER))
1759 break;
1760 continue;
1761 }
1762 KASSERT((x & VPB_BIT_SHARED) != 0 ||
1763 (x & ~VPB_BIT_WAITERS) == VPB_CURTHREAD_EXCLUSIVE,
1764 ("vm_page_busy_release: %p xbusy not owned.", m));
1765 if (!atomic_fcmpset_rel_int(&m->busy_lock, &x, VPB_UNBUSIED))
1766 continue;
1767 if ((x & VPB_BIT_WAITERS) != 0)
1768 wakeup(m);
1769 break;
1770 }
1771 }
1772
1773 /*
1774 * vm_page_find_least:
1775 *
1776 * Returns the page associated with the object with least pindex
1777 * greater than or equal to the parameter pindex, or NULL.
1778 *
1779 * The object must be locked.
1780 */
1781 vm_page_t
vm_page_find_least(vm_object_t object,vm_pindex_t pindex)1782 vm_page_find_least(vm_object_t object, vm_pindex_t pindex)
1783 {
1784 vm_page_t m;
1785
1786 VM_OBJECT_ASSERT_LOCKED(object);
1787 if ((m = TAILQ_FIRST(&object->memq)) != NULL && m->pindex < pindex)
1788 m = vm_radix_lookup_ge(&object->rtree, pindex);
1789 return (m);
1790 }
1791
1792 /*
1793 * Returns the given page's successor (by pindex) within the object if it is
1794 * resident; if none is found, NULL is returned.
1795 *
1796 * The object must be locked.
1797 */
1798 vm_page_t
vm_page_next(vm_page_t m)1799 vm_page_next(vm_page_t m)
1800 {
1801 vm_page_t next;
1802
1803 VM_OBJECT_ASSERT_LOCKED(m->object);
1804 if ((next = TAILQ_NEXT(m, listq)) != NULL) {
1805 MPASS(next->object == m->object);
1806 if (next->pindex != m->pindex + 1)
1807 next = NULL;
1808 }
1809 return (next);
1810 }
1811
1812 /*
1813 * Returns the given page's predecessor (by pindex) within the object if it is
1814 * resident; if none is found, NULL is returned.
1815 *
1816 * The object must be locked.
1817 */
1818 vm_page_t
vm_page_prev(vm_page_t m)1819 vm_page_prev(vm_page_t m)
1820 {
1821 vm_page_t prev;
1822
1823 VM_OBJECT_ASSERT_LOCKED(m->object);
1824 if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL) {
1825 MPASS(prev->object == m->object);
1826 if (prev->pindex != m->pindex - 1)
1827 prev = NULL;
1828 }
1829 return (prev);
1830 }
1831
1832 /*
1833 * Uses the page mnew as a replacement for an existing page at index
1834 * pindex which must be already present in the object.
1835 *
1836 * Both pages must be exclusively busied on enter. The old page is
1837 * unbusied on exit.
1838 *
1839 * A return value of true means mold is now free. If this is not the
1840 * final ref and the caller does not hold a wire reference it may not
1841 * continue to access the page.
1842 */
1843 static bool
vm_page_replace_hold(vm_page_t mnew,vm_object_t object,vm_pindex_t pindex,vm_page_t mold)1844 vm_page_replace_hold(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex,
1845 vm_page_t mold)
1846 {
1847 vm_page_t mret __diagused;
1848 bool dropped;
1849
1850 VM_OBJECT_ASSERT_WLOCKED(object);
1851 vm_page_assert_xbusied(mold);
1852 KASSERT(mnew->object == NULL && (mnew->ref_count & VPRC_OBJREF) == 0,
1853 ("vm_page_replace: page %p already in object", mnew));
1854
1855 /*
1856 * This function mostly follows vm_page_insert() and
1857 * vm_page_remove() without the radix, object count and vnode
1858 * dance. Double check such functions for more comments.
1859 */
1860
1861 mnew->object = object;
1862 mnew->pindex = pindex;
1863 atomic_set_int(&mnew->ref_count, VPRC_OBJREF);
1864 mret = vm_radix_replace(&object->rtree, mnew);
1865 KASSERT(mret == mold,
1866 ("invalid page replacement, mold=%p, mret=%p", mold, mret));
1867 KASSERT((mold->oflags & VPO_UNMANAGED) ==
1868 (mnew->oflags & VPO_UNMANAGED),
1869 ("vm_page_replace: mismatched VPO_UNMANAGED"));
1870
1871 /* Keep the resident page list in sorted order. */
1872 TAILQ_INSERT_AFTER(&object->memq, mold, mnew, listq);
1873 TAILQ_REMOVE(&object->memq, mold, listq);
1874 mold->object = NULL;
1875
1876 /*
1877 * The object's resident_page_count does not change because we have
1878 * swapped one page for another, but the generation count should
1879 * change if the page is dirty.
1880 */
1881 if (pmap_page_is_write_mapped(mnew))
1882 vm_object_set_writeable_dirty(object);
1883 dropped = vm_page_drop(mold, VPRC_OBJREF) == VPRC_OBJREF;
1884 vm_page_xunbusy(mold);
1885
1886 return (dropped);
1887 }
1888
1889 void
vm_page_replace(vm_page_t mnew,vm_object_t object,vm_pindex_t pindex,vm_page_t mold)1890 vm_page_replace(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex,
1891 vm_page_t mold)
1892 {
1893
1894 vm_page_assert_xbusied(mnew);
1895
1896 if (vm_page_replace_hold(mnew, object, pindex, mold))
1897 vm_page_free(mold);
1898 }
1899
1900 /*
1901 * vm_page_rename:
1902 *
1903 * Move the given memory entry from its
1904 * current object to the specified target object/offset.
1905 *
1906 * Note: swap associated with the page must be invalidated by the move. We
1907 * have to do this for several reasons: (1) we aren't freeing the
1908 * page, (2) we are dirtying the page, (3) the VM system is probably
1909 * moving the page from object A to B, and will then later move
1910 * the backing store from A to B and we can't have a conflict.
1911 *
1912 * Note: we *always* dirty the page. It is necessary both for the
1913 * fact that we moved it, and because we may be invalidating
1914 * swap.
1915 *
1916 * The objects must be locked.
1917 */
1918 int
vm_page_rename(vm_page_t m,vm_object_t new_object,vm_pindex_t new_pindex)1919 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex)
1920 {
1921 vm_page_t mpred;
1922 vm_pindex_t opidx;
1923
1924 VM_OBJECT_ASSERT_WLOCKED(new_object);
1925
1926 KASSERT(m->ref_count != 0, ("vm_page_rename: page %p has no refs", m));
1927
1928 /*
1929 * Create a custom version of vm_page_insert() which does not depend
1930 * by m_prev and can cheat on the implementation aspects of the
1931 * function.
1932 */
1933 opidx = m->pindex;
1934 m->pindex = new_pindex;
1935 if (vm_radix_insert_lookup_lt(&new_object->rtree, m, &mpred) != 0) {
1936 m->pindex = opidx;
1937 return (1);
1938 }
1939
1940 /*
1941 * The operation cannot fail anymore. The removal must happen before
1942 * the listq iterator is tainted.
1943 */
1944 m->pindex = opidx;
1945 vm_page_object_remove(m);
1946
1947 /* Return back to the new pindex to complete vm_page_insert(). */
1948 m->pindex = new_pindex;
1949 m->object = new_object;
1950
1951 vm_page_insert_radixdone(m, new_object, mpred);
1952 vm_page_dirty(m);
1953 vm_pager_page_inserted(new_object, m);
1954 return (0);
1955 }
1956
1957 /*
1958 * vm_page_alloc:
1959 *
1960 * Allocate and return a page that is associated with the specified
1961 * object and offset pair. By default, this page is exclusive busied.
1962 *
1963 * The caller must always specify an allocation class.
1964 *
1965 * allocation classes:
1966 * VM_ALLOC_NORMAL normal process request
1967 * VM_ALLOC_SYSTEM system *really* needs a page
1968 * VM_ALLOC_INTERRUPT interrupt time request
1969 *
1970 * optional allocation flags:
1971 * VM_ALLOC_COUNT(number) the number of additional pages that the caller
1972 * intends to allocate
1973 * VM_ALLOC_NOBUSY do not exclusive busy the page
1974 * VM_ALLOC_NODUMP do not include the page in a kernel core dump
1975 * VM_ALLOC_SBUSY shared busy the allocated page
1976 * VM_ALLOC_WIRED wire the allocated page
1977 * VM_ALLOC_ZERO prefer a zeroed page
1978 */
1979 vm_page_t
vm_page_alloc(vm_object_t object,vm_pindex_t pindex,int req)1980 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req)
1981 {
1982
1983 return (vm_page_alloc_after(object, pindex, req,
1984 vm_radix_lookup_le(&object->rtree, pindex)));
1985 }
1986
1987 vm_page_t
vm_page_alloc_domain(vm_object_t object,vm_pindex_t pindex,int domain,int req)1988 vm_page_alloc_domain(vm_object_t object, vm_pindex_t pindex, int domain,
1989 int req)
1990 {
1991
1992 return (vm_page_alloc_domain_after(object, pindex, domain, req,
1993 vm_radix_lookup_le(&object->rtree, pindex)));
1994 }
1995
1996 /*
1997 * Allocate a page in the specified object with the given page index. To
1998 * optimize insertion of the page into the object, the caller must also specifiy
1999 * the resident page in the object with largest index smaller than the given
2000 * page index, or NULL if no such page exists.
2001 */
2002 vm_page_t
vm_page_alloc_after(vm_object_t object,vm_pindex_t pindex,int req,vm_page_t mpred)2003 vm_page_alloc_after(vm_object_t object, vm_pindex_t pindex,
2004 int req, vm_page_t mpred)
2005 {
2006 struct vm_domainset_iter di;
2007 vm_page_t m;
2008 int domain;
2009
2010 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req);
2011 do {
2012 m = vm_page_alloc_domain_after(object, pindex, domain, req,
2013 mpred);
2014 if (m != NULL)
2015 break;
2016 } while (vm_domainset_iter_page(&di, object, &domain) == 0);
2017
2018 return (m);
2019 }
2020
2021 /*
2022 * Returns true if the number of free pages exceeds the minimum
2023 * for the request class and false otherwise.
2024 */
2025 static int
_vm_domain_allocate(struct vm_domain * vmd,int req_class,int npages)2026 _vm_domain_allocate(struct vm_domain *vmd, int req_class, int npages)
2027 {
2028 u_int limit, old, new;
2029
2030 if (req_class == VM_ALLOC_INTERRUPT)
2031 limit = 0;
2032 else if (req_class == VM_ALLOC_SYSTEM)
2033 limit = vmd->vmd_interrupt_free_min;
2034 else
2035 limit = vmd->vmd_free_reserved;
2036
2037 /*
2038 * Attempt to reserve the pages. Fail if we're below the limit.
2039 */
2040 limit += npages;
2041 old = vmd->vmd_free_count;
2042 do {
2043 if (old < limit)
2044 return (0);
2045 new = old - npages;
2046 } while (atomic_fcmpset_int(&vmd->vmd_free_count, &old, new) == 0);
2047
2048 /* Wake the page daemon if we've crossed the threshold. */
2049 if (vm_paging_needed(vmd, new) && !vm_paging_needed(vmd, old))
2050 pagedaemon_wakeup(vmd->vmd_domain);
2051
2052 /* Only update bitsets on transitions. */
2053 if ((old >= vmd->vmd_free_min && new < vmd->vmd_free_min) ||
2054 (old >= vmd->vmd_free_severe && new < vmd->vmd_free_severe))
2055 vm_domain_set(vmd);
2056
2057 return (1);
2058 }
2059
2060 int
vm_domain_allocate(struct vm_domain * vmd,int req,int npages)2061 vm_domain_allocate(struct vm_domain *vmd, int req, int npages)
2062 {
2063 int req_class;
2064
2065 /*
2066 * The page daemon is allowed to dig deeper into the free page list.
2067 */
2068 req_class = req & VM_ALLOC_CLASS_MASK;
2069 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT)
2070 req_class = VM_ALLOC_SYSTEM;
2071 return (_vm_domain_allocate(vmd, req_class, npages));
2072 }
2073
2074 vm_page_t
vm_page_alloc_domain_after(vm_object_t object,vm_pindex_t pindex,int domain,int req,vm_page_t mpred)2075 vm_page_alloc_domain_after(vm_object_t object, vm_pindex_t pindex, int domain,
2076 int req, vm_page_t mpred)
2077 {
2078 struct vm_domain *vmd;
2079 vm_page_t m;
2080 int flags;
2081
2082 #define VPA_FLAGS (VM_ALLOC_CLASS_MASK | VM_ALLOC_WAITFAIL | \
2083 VM_ALLOC_NOWAIT | VM_ALLOC_NOBUSY | \
2084 VM_ALLOC_SBUSY | VM_ALLOC_WIRED | \
2085 VM_ALLOC_NODUMP | VM_ALLOC_ZERO | VM_ALLOC_COUNT_MASK)
2086 KASSERT((req & ~VPA_FLAGS) == 0,
2087 ("invalid request %#x", req));
2088 KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) !=
2089 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)),
2090 ("invalid request %#x", req));
2091 KASSERT(mpred == NULL || mpred->pindex < pindex,
2092 ("mpred %p doesn't precede pindex 0x%jx", mpred,
2093 (uintmax_t)pindex));
2094 VM_OBJECT_ASSERT_WLOCKED(object);
2095
2096 flags = 0;
2097 m = NULL;
2098 if (!vm_pager_can_alloc_page(object, pindex))
2099 return (NULL);
2100 again:
2101 #if VM_NRESERVLEVEL > 0
2102 /*
2103 * Can we allocate the page from a reservation?
2104 */
2105 if (vm_object_reserv(object) &&
2106 (m = vm_reserv_alloc_page(object, pindex, domain, req, mpred)) !=
2107 NULL) {
2108 goto found;
2109 }
2110 #endif
2111 vmd = VM_DOMAIN(domain);
2112 if (vmd->vmd_pgcache[VM_FREEPOOL_DEFAULT].zone != NULL) {
2113 m = uma_zalloc(vmd->vmd_pgcache[VM_FREEPOOL_DEFAULT].zone,
2114 M_NOWAIT | M_NOVM);
2115 if (m != NULL) {
2116 flags |= PG_PCPU_CACHE;
2117 goto found;
2118 }
2119 }
2120 if (vm_domain_allocate(vmd, req, 1)) {
2121 /*
2122 * If not, allocate it from the free page queues.
2123 */
2124 vm_domain_free_lock(vmd);
2125 m = vm_phys_alloc_pages(domain, VM_FREEPOOL_DEFAULT, 0);
2126 vm_domain_free_unlock(vmd);
2127 if (m == NULL) {
2128 vm_domain_freecnt_inc(vmd, 1);
2129 #if VM_NRESERVLEVEL > 0
2130 if (vm_reserv_reclaim_inactive(domain))
2131 goto again;
2132 #endif
2133 }
2134 }
2135 if (m == NULL) {
2136 /*
2137 * Not allocatable, give up.
2138 */
2139 if (vm_domain_alloc_fail(vmd, object, req))
2140 goto again;
2141 return (NULL);
2142 }
2143
2144 /*
2145 * At this point we had better have found a good page.
2146 */
2147 found:
2148 vm_page_dequeue(m);
2149 vm_page_alloc_check(m);
2150
2151 /*
2152 * Initialize the page. Only the PG_ZERO flag is inherited.
2153 */
2154 flags |= m->flags & PG_ZERO;
2155 if ((req & VM_ALLOC_NODUMP) != 0)
2156 flags |= PG_NODUMP;
2157 m->flags = flags;
2158 m->a.flags = 0;
2159 m->oflags = (object->flags & OBJ_UNMANAGED) != 0 ? VPO_UNMANAGED : 0;
2160 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0)
2161 m->busy_lock = VPB_CURTHREAD_EXCLUSIVE;
2162 else if ((req & VM_ALLOC_SBUSY) != 0)
2163 m->busy_lock = VPB_SHARERS_WORD(1);
2164 else
2165 m->busy_lock = VPB_UNBUSIED;
2166 if (req & VM_ALLOC_WIRED) {
2167 vm_wire_add(1);
2168 m->ref_count = 1;
2169 }
2170 m->a.act_count = 0;
2171
2172 if (vm_page_insert_after(m, object, pindex, mpred)) {
2173 if (req & VM_ALLOC_WIRED) {
2174 vm_wire_sub(1);
2175 m->ref_count = 0;
2176 }
2177 KASSERT(m->object == NULL, ("page %p has object", m));
2178 m->oflags = VPO_UNMANAGED;
2179 m->busy_lock = VPB_UNBUSIED;
2180 /* Don't change PG_ZERO. */
2181 vm_page_free_toq(m);
2182 if (req & VM_ALLOC_WAITFAIL) {
2183 VM_OBJECT_WUNLOCK(object);
2184 vm_radix_wait();
2185 VM_OBJECT_WLOCK(object);
2186 }
2187 return (NULL);
2188 }
2189
2190 /* Ignore device objects; the pager sets "memattr" for them. */
2191 if (object->memattr != VM_MEMATTR_DEFAULT &&
2192 (object->flags & OBJ_FICTITIOUS) == 0)
2193 pmap_page_set_memattr(m, object->memattr);
2194
2195 return (m);
2196 }
2197
2198 /*
2199 * vm_page_alloc_contig:
2200 *
2201 * Allocate a contiguous set of physical pages of the given size "npages"
2202 * from the free lists. All of the physical pages must be at or above
2203 * the given physical address "low" and below the given physical address
2204 * "high". The given value "alignment" determines the alignment of the
2205 * first physical page in the set. If the given value "boundary" is
2206 * non-zero, then the set of physical pages cannot cross any physical
2207 * address boundary that is a multiple of that value. Both "alignment"
2208 * and "boundary" must be a power of two.
2209 *
2210 * If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT,
2211 * then the memory attribute setting for the physical pages is configured
2212 * to the object's memory attribute setting. Otherwise, the memory
2213 * attribute setting for the physical pages is configured to "memattr",
2214 * overriding the object's memory attribute setting. However, if the
2215 * object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the
2216 * memory attribute setting for the physical pages cannot be configured
2217 * to VM_MEMATTR_DEFAULT.
2218 *
2219 * The specified object may not contain fictitious pages.
2220 *
2221 * The caller must always specify an allocation class.
2222 *
2223 * allocation classes:
2224 * VM_ALLOC_NORMAL normal process request
2225 * VM_ALLOC_SYSTEM system *really* needs a page
2226 * VM_ALLOC_INTERRUPT interrupt time request
2227 *
2228 * optional allocation flags:
2229 * VM_ALLOC_NOBUSY do not exclusive busy the page
2230 * VM_ALLOC_NODUMP do not include the page in a kernel core dump
2231 * VM_ALLOC_SBUSY shared busy the allocated page
2232 * VM_ALLOC_WIRED wire the allocated page
2233 * VM_ALLOC_ZERO prefer a zeroed page
2234 */
2235 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)2236 vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req,
2237 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
2238 vm_paddr_t boundary, vm_memattr_t memattr)
2239 {
2240 struct vm_domainset_iter di;
2241 vm_page_t bounds[2];
2242 vm_page_t m;
2243 int domain;
2244 int start_segind;
2245
2246 start_segind = -1;
2247
2248 vm_domainset_iter_page_init(&di, object, pindex, &domain, &req);
2249 do {
2250 m = vm_page_alloc_contig_domain(object, pindex, domain, req,
2251 npages, low, high, alignment, boundary, memattr);
2252 if (m != NULL)
2253 break;
2254 if (start_segind == -1)
2255 start_segind = vm_phys_lookup_segind(low);
2256 if (vm_phys_find_range(bounds, start_segind, domain,
2257 npages, low, high) == -1) {
2258 vm_domainset_iter_ignore(&di, domain);
2259 }
2260 } while (vm_domainset_iter_page(&di, object, &domain) == 0);
2261
2262 return (m);
2263 }
2264
2265 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)2266 vm_page_find_contig_domain(int domain, int req, u_long npages, vm_paddr_t low,
2267 vm_paddr_t high, u_long alignment, vm_paddr_t boundary)
2268 {
2269 struct vm_domain *vmd;
2270 vm_page_t m_ret;
2271
2272 /*
2273 * Can we allocate the pages without the number of free pages falling
2274 * below the lower bound for the allocation class?
2275 */
2276 vmd = VM_DOMAIN(domain);
2277 if (!vm_domain_allocate(vmd, req, npages))
2278 return (NULL);
2279 /*
2280 * Try to allocate the pages from the free page queues.
2281 */
2282 vm_domain_free_lock(vmd);
2283 m_ret = vm_phys_alloc_contig(domain, npages, low, high,
2284 alignment, boundary);
2285 vm_domain_free_unlock(vmd);
2286 if (m_ret != NULL)
2287 return (m_ret);
2288 #if VM_NRESERVLEVEL > 0
2289 /*
2290 * Try to break a reservation to allocate the pages.
2291 */
2292 if ((req & VM_ALLOC_NORECLAIM) == 0) {
2293 m_ret = vm_reserv_reclaim_contig(domain, npages, low,
2294 high, alignment, boundary);
2295 if (m_ret != NULL)
2296 return (m_ret);
2297 }
2298 #endif
2299 vm_domain_freecnt_inc(vmd, npages);
2300 return (NULL);
2301 }
2302
2303 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)2304 vm_page_alloc_contig_domain(vm_object_t object, vm_pindex_t pindex, int domain,
2305 int req, u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
2306 vm_paddr_t boundary, vm_memattr_t memattr)
2307 {
2308 vm_page_t m, m_ret, mpred;
2309 u_int busy_lock, flags, oflags;
2310
2311 #define VPAC_FLAGS (VPA_FLAGS | VM_ALLOC_NORECLAIM)
2312 KASSERT((req & ~VPAC_FLAGS) == 0,
2313 ("invalid request %#x", req));
2314 KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) !=
2315 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)),
2316 ("invalid request %#x", req));
2317 KASSERT((req & (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM)) !=
2318 (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM),
2319 ("invalid request %#x", req));
2320 VM_OBJECT_ASSERT_WLOCKED(object);
2321 KASSERT((object->flags & OBJ_FICTITIOUS) == 0,
2322 ("vm_page_alloc_contig: object %p has fictitious pages",
2323 object));
2324 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero"));
2325
2326 mpred = vm_radix_lookup_le(&object->rtree, pindex);
2327 KASSERT(mpred == NULL || mpred->pindex != pindex,
2328 ("vm_page_alloc_contig: pindex already allocated"));
2329 for (;;) {
2330 #if VM_NRESERVLEVEL > 0
2331 /*
2332 * Can we allocate the pages from a reservation?
2333 */
2334 if (vm_object_reserv(object) &&
2335 (m_ret = vm_reserv_alloc_contig(object, pindex, domain, req,
2336 mpred, npages, low, high, alignment, boundary)) != NULL) {
2337 break;
2338 }
2339 #endif
2340 if ((m_ret = vm_page_find_contig_domain(domain, req, npages,
2341 low, high, alignment, boundary)) != NULL)
2342 break;
2343 if (!vm_domain_alloc_fail(VM_DOMAIN(domain), object, req))
2344 return (NULL);
2345 }
2346 for (m = m_ret; m < &m_ret[npages]; m++) {
2347 vm_page_dequeue(m);
2348 vm_page_alloc_check(m);
2349 }
2350
2351 /*
2352 * Initialize the pages. Only the PG_ZERO flag is inherited.
2353 */
2354 flags = PG_ZERO;
2355 if ((req & VM_ALLOC_NODUMP) != 0)
2356 flags |= PG_NODUMP;
2357 oflags = (object->flags & OBJ_UNMANAGED) != 0 ? VPO_UNMANAGED : 0;
2358 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0)
2359 busy_lock = VPB_CURTHREAD_EXCLUSIVE;
2360 else if ((req & VM_ALLOC_SBUSY) != 0)
2361 busy_lock = VPB_SHARERS_WORD(1);
2362 else
2363 busy_lock = VPB_UNBUSIED;
2364 if ((req & VM_ALLOC_WIRED) != 0)
2365 vm_wire_add(npages);
2366 if (object->memattr != VM_MEMATTR_DEFAULT &&
2367 memattr == VM_MEMATTR_DEFAULT)
2368 memattr = object->memattr;
2369 for (m = m_ret; m < &m_ret[npages]; m++) {
2370 m->a.flags = 0;
2371 m->flags = (m->flags | PG_NODUMP) & flags;
2372 m->busy_lock = busy_lock;
2373 if ((req & VM_ALLOC_WIRED) != 0)
2374 m->ref_count = 1;
2375 m->a.act_count = 0;
2376 m->oflags = oflags;
2377 if (vm_page_insert_after(m, object, pindex, mpred)) {
2378 if ((req & VM_ALLOC_WIRED) != 0)
2379 vm_wire_sub(npages);
2380 KASSERT(m->object == NULL,
2381 ("page %p has object", m));
2382 mpred = m;
2383 for (m = m_ret; m < &m_ret[npages]; m++) {
2384 if (m <= mpred &&
2385 (req & VM_ALLOC_WIRED) != 0)
2386 m->ref_count = 0;
2387 m->oflags = VPO_UNMANAGED;
2388 m->busy_lock = VPB_UNBUSIED;
2389 /* Don't change PG_ZERO. */
2390 vm_page_free_toq(m);
2391 }
2392 if (req & VM_ALLOC_WAITFAIL) {
2393 VM_OBJECT_WUNLOCK(object);
2394 vm_radix_wait();
2395 VM_OBJECT_WLOCK(object);
2396 }
2397 return (NULL);
2398 }
2399 mpred = m;
2400 if (memattr != VM_MEMATTR_DEFAULT)
2401 pmap_page_set_memattr(m, memattr);
2402 pindex++;
2403 }
2404 return (m_ret);
2405 }
2406
2407 /*
2408 * Allocate a physical page that is not intended to be inserted into a VM
2409 * object. If the "freelist" parameter is not equal to VM_NFREELIST, then only
2410 * pages from the specified vm_phys freelist will be returned.
2411 */
2412 static __always_inline vm_page_t
_vm_page_alloc_noobj_domain(int domain,const int freelist,int req)2413 _vm_page_alloc_noobj_domain(int domain, const int freelist, int req)
2414 {
2415 struct vm_domain *vmd;
2416 vm_page_t m;
2417 int flags;
2418
2419 #define VPAN_FLAGS (VM_ALLOC_CLASS_MASK | VM_ALLOC_WAITFAIL | \
2420 VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | \
2421 VM_ALLOC_NOBUSY | VM_ALLOC_WIRED | \
2422 VM_ALLOC_NODUMP | VM_ALLOC_ZERO | VM_ALLOC_COUNT_MASK)
2423 KASSERT((req & ~VPAN_FLAGS) == 0,
2424 ("invalid request %#x", req));
2425
2426 flags = (req & VM_ALLOC_NODUMP) != 0 ? PG_NODUMP : 0;
2427 vmd = VM_DOMAIN(domain);
2428 again:
2429 if (freelist == VM_NFREELIST &&
2430 vmd->vmd_pgcache[VM_FREEPOOL_DIRECT].zone != NULL) {
2431 m = uma_zalloc(vmd->vmd_pgcache[VM_FREEPOOL_DIRECT].zone,
2432 M_NOWAIT | M_NOVM);
2433 if (m != NULL) {
2434 flags |= PG_PCPU_CACHE;
2435 goto found;
2436 }
2437 }
2438
2439 if (vm_domain_allocate(vmd, req, 1)) {
2440 vm_domain_free_lock(vmd);
2441 if (freelist == VM_NFREELIST)
2442 m = vm_phys_alloc_pages(domain, VM_FREEPOOL_DIRECT, 0);
2443 else
2444 m = vm_phys_alloc_freelist_pages(domain, freelist,
2445 VM_FREEPOOL_DIRECT, 0);
2446 vm_domain_free_unlock(vmd);
2447 if (m == NULL) {
2448 vm_domain_freecnt_inc(vmd, 1);
2449 #if VM_NRESERVLEVEL > 0
2450 if (freelist == VM_NFREELIST &&
2451 vm_reserv_reclaim_inactive(domain))
2452 goto again;
2453 #endif
2454 }
2455 }
2456 if (m == NULL) {
2457 if (vm_domain_alloc_fail(vmd, NULL, req))
2458 goto again;
2459 return (NULL);
2460 }
2461
2462 found:
2463 vm_page_dequeue(m);
2464 vm_page_alloc_check(m);
2465
2466 /*
2467 * Consumers should not rely on a useful default pindex value.
2468 */
2469 m->pindex = 0xdeadc0dedeadc0de;
2470 m->flags = (m->flags & PG_ZERO) | flags;
2471 m->a.flags = 0;
2472 m->oflags = VPO_UNMANAGED;
2473 m->busy_lock = VPB_UNBUSIED;
2474 if ((req & VM_ALLOC_WIRED) != 0) {
2475 vm_wire_add(1);
2476 m->ref_count = 1;
2477 }
2478
2479 if ((req & VM_ALLOC_ZERO) != 0 && (m->flags & PG_ZERO) == 0)
2480 pmap_zero_page(m);
2481
2482 return (m);
2483 }
2484
2485 vm_page_t
vm_page_alloc_freelist(int freelist,int req)2486 vm_page_alloc_freelist(int freelist, int req)
2487 {
2488 struct vm_domainset_iter di;
2489 vm_page_t m;
2490 int domain;
2491
2492 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req);
2493 do {
2494 m = vm_page_alloc_freelist_domain(domain, freelist, req);
2495 if (m != NULL)
2496 break;
2497 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0);
2498
2499 return (m);
2500 }
2501
2502 vm_page_t
vm_page_alloc_freelist_domain(int domain,int freelist,int req)2503 vm_page_alloc_freelist_domain(int domain, int freelist, int req)
2504 {
2505 KASSERT(freelist >= 0 && freelist < VM_NFREELIST,
2506 ("%s: invalid freelist %d", __func__, freelist));
2507
2508 return (_vm_page_alloc_noobj_domain(domain, freelist, req));
2509 }
2510
2511 vm_page_t
vm_page_alloc_noobj(int req)2512 vm_page_alloc_noobj(int req)
2513 {
2514 struct vm_domainset_iter di;
2515 vm_page_t m;
2516 int domain;
2517
2518 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req);
2519 do {
2520 m = vm_page_alloc_noobj_domain(domain, req);
2521 if (m != NULL)
2522 break;
2523 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0);
2524
2525 return (m);
2526 }
2527
2528 vm_page_t
vm_page_alloc_noobj_domain(int domain,int req)2529 vm_page_alloc_noobj_domain(int domain, int req)
2530 {
2531 return (_vm_page_alloc_noobj_domain(domain, VM_NFREELIST, req));
2532 }
2533
2534 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)2535 vm_page_alloc_noobj_contig(int req, u_long npages, vm_paddr_t low,
2536 vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
2537 vm_memattr_t memattr)
2538 {
2539 struct vm_domainset_iter di;
2540 vm_page_t m;
2541 int domain;
2542
2543 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req);
2544 do {
2545 m = vm_page_alloc_noobj_contig_domain(domain, req, npages, low,
2546 high, alignment, boundary, memattr);
2547 if (m != NULL)
2548 break;
2549 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0);
2550
2551 return (m);
2552 }
2553
2554 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)2555 vm_page_alloc_noobj_contig_domain(int domain, int req, u_long npages,
2556 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
2557 vm_memattr_t memattr)
2558 {
2559 vm_page_t m, m_ret;
2560 u_int flags;
2561
2562 #define VPANC_FLAGS (VPAN_FLAGS | VM_ALLOC_NORECLAIM)
2563 KASSERT((req & ~VPANC_FLAGS) == 0,
2564 ("invalid request %#x", req));
2565 KASSERT((req & (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM)) !=
2566 (VM_ALLOC_WAITOK | VM_ALLOC_NORECLAIM),
2567 ("invalid request %#x", req));
2568 KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) !=
2569 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)),
2570 ("invalid request %#x", req));
2571 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero"));
2572
2573 while ((m_ret = vm_page_find_contig_domain(domain, req, npages,
2574 low, high, alignment, boundary)) == NULL) {
2575 if (!vm_domain_alloc_fail(VM_DOMAIN(domain), NULL, req))
2576 return (NULL);
2577 }
2578
2579 /*
2580 * Initialize the pages. Only the PG_ZERO flag is inherited.
2581 */
2582 flags = PG_ZERO;
2583 if ((req & VM_ALLOC_NODUMP) != 0)
2584 flags |= PG_NODUMP;
2585 if ((req & VM_ALLOC_WIRED) != 0)
2586 vm_wire_add(npages);
2587 for (m = m_ret; m < &m_ret[npages]; m++) {
2588 vm_page_dequeue(m);
2589 vm_page_alloc_check(m);
2590
2591 /*
2592 * Consumers should not rely on a useful default pindex value.
2593 */
2594 m->pindex = 0xdeadc0dedeadc0de;
2595 m->a.flags = 0;
2596 m->flags = (m->flags | PG_NODUMP) & flags;
2597 m->busy_lock = VPB_UNBUSIED;
2598 if ((req & VM_ALLOC_WIRED) != 0)
2599 m->ref_count = 1;
2600 m->a.act_count = 0;
2601 m->oflags = VPO_UNMANAGED;
2602
2603 /*
2604 * Zero the page before updating any mappings since the page is
2605 * not yet shared with any devices which might require the
2606 * non-default memory attribute. pmap_page_set_memattr()
2607 * flushes data caches before returning.
2608 */
2609 if ((req & VM_ALLOC_ZERO) != 0 && (m->flags & PG_ZERO) == 0)
2610 pmap_zero_page(m);
2611 if (memattr != VM_MEMATTR_DEFAULT)
2612 pmap_page_set_memattr(m, memattr);
2613 }
2614 return (m_ret);
2615 }
2616
2617 /*
2618 * Check a page that has been freshly dequeued from a freelist.
2619 */
2620 static void
vm_page_alloc_check(vm_page_t m)2621 vm_page_alloc_check(vm_page_t m)
2622 {
2623
2624 KASSERT(m->object == NULL, ("page %p has object", m));
2625 KASSERT(m->a.queue == PQ_NONE &&
2626 (m->a.flags & PGA_QUEUE_STATE_MASK) == 0,
2627 ("page %p has unexpected queue %d, flags %#x",
2628 m, m->a.queue, (m->a.flags & PGA_QUEUE_STATE_MASK)));
2629 KASSERT(m->ref_count == 0, ("page %p has references", m));
2630 KASSERT(vm_page_busy_freed(m), ("page %p is not freed", m));
2631 KASSERT(m->dirty == 0, ("page %p is dirty", m));
2632 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT,
2633 ("page %p has unexpected memattr %d",
2634 m, pmap_page_get_memattr(m)));
2635 KASSERT(vm_page_none_valid(m), ("free page %p is valid", m));
2636 pmap_vm_page_alloc_check(m);
2637 }
2638
2639 static int
vm_page_zone_import(void * arg,void ** store,int cnt,int domain,int flags)2640 vm_page_zone_import(void *arg, void **store, int cnt, int domain, int flags)
2641 {
2642 struct vm_domain *vmd;
2643 struct vm_pgcache *pgcache;
2644 int i;
2645
2646 pgcache = arg;
2647 vmd = VM_DOMAIN(pgcache->domain);
2648
2649 /*
2650 * The page daemon should avoid creating extra memory pressure since its
2651 * main purpose is to replenish the store of free pages.
2652 */
2653 if (vmd->vmd_severeset || curproc == pageproc ||
2654 !_vm_domain_allocate(vmd, VM_ALLOC_NORMAL, cnt))
2655 return (0);
2656 domain = vmd->vmd_domain;
2657 vm_domain_free_lock(vmd);
2658 i = vm_phys_alloc_npages(domain, pgcache->pool, cnt,
2659 (vm_page_t *)store);
2660 vm_domain_free_unlock(vmd);
2661 if (cnt != i)
2662 vm_domain_freecnt_inc(vmd, cnt - i);
2663
2664 return (i);
2665 }
2666
2667 static void
vm_page_zone_release(void * arg,void ** store,int cnt)2668 vm_page_zone_release(void *arg, void **store, int cnt)
2669 {
2670 struct vm_domain *vmd;
2671 struct vm_pgcache *pgcache;
2672 vm_page_t m;
2673 int i;
2674
2675 pgcache = arg;
2676 vmd = VM_DOMAIN(pgcache->domain);
2677 vm_domain_free_lock(vmd);
2678 for (i = 0; i < cnt; i++) {
2679 m = (vm_page_t)store[i];
2680 vm_phys_free_pages(m, 0);
2681 }
2682 vm_domain_free_unlock(vmd);
2683 vm_domain_freecnt_inc(vmd, cnt);
2684 }
2685
2686 #define VPSC_ANY 0 /* No restrictions. */
2687 #define VPSC_NORESERV 1 /* Skip reservations; implies VPSC_NOSUPER. */
2688 #define VPSC_NOSUPER 2 /* Skip superpages. */
2689
2690 /*
2691 * vm_page_scan_contig:
2692 *
2693 * Scan vm_page_array[] between the specified entries "m_start" and
2694 * "m_end" for a run of contiguous physical pages that satisfy the
2695 * specified conditions, and return the lowest page in the run. The
2696 * specified "alignment" determines the alignment of the lowest physical
2697 * page in the run. If the specified "boundary" is non-zero, then the
2698 * run of physical pages cannot span a physical address that is a
2699 * multiple of "boundary".
2700 *
2701 * "m_end" is never dereferenced, so it need not point to a vm_page
2702 * structure within vm_page_array[].
2703 *
2704 * "npages" must be greater than zero. "m_start" and "m_end" must not
2705 * span a hole (or discontiguity) in the physical address space. Both
2706 * "alignment" and "boundary" must be a power of two.
2707 */
2708 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)2709 vm_page_scan_contig(u_long npages, vm_page_t m_start, vm_page_t m_end,
2710 u_long alignment, vm_paddr_t boundary, int options)
2711 {
2712 vm_object_t object;
2713 vm_paddr_t pa;
2714 vm_page_t m, m_run;
2715 #if VM_NRESERVLEVEL > 0
2716 int level;
2717 #endif
2718 int m_inc, order, run_ext, run_len;
2719
2720 KASSERT(npages > 0, ("npages is 0"));
2721 KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
2722 KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
2723 m_run = NULL;
2724 run_len = 0;
2725 for (m = m_start; m < m_end && run_len < npages; m += m_inc) {
2726 KASSERT((m->flags & PG_MARKER) == 0,
2727 ("page %p is PG_MARKER", m));
2728 KASSERT((m->flags & PG_FICTITIOUS) == 0 || m->ref_count >= 1,
2729 ("fictitious page %p has invalid ref count", m));
2730
2731 /*
2732 * If the current page would be the start of a run, check its
2733 * physical address against the end, alignment, and boundary
2734 * conditions. If it doesn't satisfy these conditions, either
2735 * terminate the scan or advance to the next page that
2736 * satisfies the failed condition.
2737 */
2738 if (run_len == 0) {
2739 KASSERT(m_run == NULL, ("m_run != NULL"));
2740 if (m + npages > m_end)
2741 break;
2742 pa = VM_PAGE_TO_PHYS(m);
2743 if (!vm_addr_align_ok(pa, alignment)) {
2744 m_inc = atop(roundup2(pa, alignment) - pa);
2745 continue;
2746 }
2747 if (!vm_addr_bound_ok(pa, ptoa(npages), boundary)) {
2748 m_inc = atop(roundup2(pa, boundary) - pa);
2749 continue;
2750 }
2751 } else
2752 KASSERT(m_run != NULL, ("m_run == NULL"));
2753
2754 retry:
2755 m_inc = 1;
2756 if (vm_page_wired(m))
2757 run_ext = 0;
2758 #if VM_NRESERVLEVEL > 0
2759 else if ((level = vm_reserv_level(m)) >= 0 &&
2760 (options & VPSC_NORESERV) != 0) {
2761 run_ext = 0;
2762 /* Advance to the end of the reservation. */
2763 pa = VM_PAGE_TO_PHYS(m);
2764 m_inc = atop(roundup2(pa + 1, vm_reserv_size(level)) -
2765 pa);
2766 }
2767 #endif
2768 else if ((object = atomic_load_ptr(&m->object)) != NULL) {
2769 /*
2770 * The page is considered eligible for relocation if
2771 * and only if it could be laundered or reclaimed by
2772 * the page daemon.
2773 */
2774 VM_OBJECT_RLOCK(object);
2775 if (object != m->object) {
2776 VM_OBJECT_RUNLOCK(object);
2777 goto retry;
2778 }
2779 /* Don't care: PG_NODUMP, PG_ZERO. */
2780 if ((object->flags & OBJ_SWAP) == 0 &&
2781 object->type != OBJT_VNODE) {
2782 run_ext = 0;
2783 #if VM_NRESERVLEVEL > 0
2784 } else if ((options & VPSC_NOSUPER) != 0 &&
2785 (level = vm_reserv_level_iffullpop(m)) >= 0) {
2786 run_ext = 0;
2787 /* Advance to the end of the superpage. */
2788 pa = VM_PAGE_TO_PHYS(m);
2789 m_inc = atop(roundup2(pa + 1,
2790 vm_reserv_size(level)) - pa);
2791 #endif
2792 } else if (object->memattr == VM_MEMATTR_DEFAULT &&
2793 vm_page_queue(m) != PQ_NONE && !vm_page_busied(m)) {
2794 /*
2795 * The page is allocated but eligible for
2796 * relocation. Extend the current run by one
2797 * page.
2798 */
2799 KASSERT(pmap_page_get_memattr(m) ==
2800 VM_MEMATTR_DEFAULT,
2801 ("page %p has an unexpected memattr", m));
2802 KASSERT((m->oflags & (VPO_SWAPINPROG |
2803 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0,
2804 ("page %p has unexpected oflags", m));
2805 /* Don't care: PGA_NOSYNC. */
2806 run_ext = 1;
2807 } else
2808 run_ext = 0;
2809 VM_OBJECT_RUNLOCK(object);
2810 #if VM_NRESERVLEVEL > 0
2811 } else if (level >= 0) {
2812 /*
2813 * The page is reserved but not yet allocated. In
2814 * other words, it is still free. Extend the current
2815 * run by one page.
2816 */
2817 run_ext = 1;
2818 #endif
2819 } else if ((order = m->order) < VM_NFREEORDER) {
2820 /*
2821 * The page is enqueued in the physical memory
2822 * allocator's free page queues. Moreover, it is the
2823 * first page in a power-of-two-sized run of
2824 * contiguous free pages. Add these pages to the end
2825 * of the current run, and jump ahead.
2826 */
2827 run_ext = 1 << order;
2828 m_inc = 1 << order;
2829 } else {
2830 /*
2831 * Skip the page for one of the following reasons: (1)
2832 * It is enqueued in the physical memory allocator's
2833 * free page queues. However, it is not the first
2834 * page in a run of contiguous free pages. (This case
2835 * rarely occurs because the scan is performed in
2836 * ascending order.) (2) It is not reserved, and it is
2837 * transitioning from free to allocated. (Conversely,
2838 * the transition from allocated to free for managed
2839 * pages is blocked by the page busy lock.) (3) It is
2840 * allocated but not contained by an object and not
2841 * wired, e.g., allocated by Xen's balloon driver.
2842 */
2843 run_ext = 0;
2844 }
2845
2846 /*
2847 * Extend or reset the current run of pages.
2848 */
2849 if (run_ext > 0) {
2850 if (run_len == 0)
2851 m_run = m;
2852 run_len += run_ext;
2853 } else {
2854 if (run_len > 0) {
2855 m_run = NULL;
2856 run_len = 0;
2857 }
2858 }
2859 }
2860 if (run_len >= npages)
2861 return (m_run);
2862 return (NULL);
2863 }
2864
2865 /*
2866 * vm_page_reclaim_run:
2867 *
2868 * Try to relocate each of the allocated virtual pages within the
2869 * specified run of physical pages to a new physical address. Free the
2870 * physical pages underlying the relocated virtual pages. A virtual page
2871 * is relocatable if and only if it could be laundered or reclaimed by
2872 * the page daemon. Whenever possible, a virtual page is relocated to a
2873 * physical address above "high".
2874 *
2875 * Returns 0 if every physical page within the run was already free or
2876 * just freed by a successful relocation. Otherwise, returns a non-zero
2877 * value indicating why the last attempt to relocate a virtual page was
2878 * unsuccessful.
2879 *
2880 * "req_class" must be an allocation class.
2881 */
2882 static int
vm_page_reclaim_run(int req_class,int domain,u_long npages,vm_page_t m_run,vm_paddr_t high)2883 vm_page_reclaim_run(int req_class, int domain, u_long npages, vm_page_t m_run,
2884 vm_paddr_t high)
2885 {
2886 struct vm_domain *vmd;
2887 struct spglist free;
2888 vm_object_t object;
2889 vm_paddr_t pa;
2890 vm_page_t m, m_end, m_new;
2891 int error, order, req;
2892
2893 KASSERT((req_class & VM_ALLOC_CLASS_MASK) == req_class,
2894 ("req_class is not an allocation class"));
2895 SLIST_INIT(&free);
2896 error = 0;
2897 m = m_run;
2898 m_end = m_run + npages;
2899 for (; error == 0 && m < m_end; m++) {
2900 KASSERT((m->flags & (PG_FICTITIOUS | PG_MARKER)) == 0,
2901 ("page %p is PG_FICTITIOUS or PG_MARKER", m));
2902
2903 /*
2904 * Racily check for wirings. Races are handled once the object
2905 * lock is held and the page is unmapped.
2906 */
2907 if (vm_page_wired(m))
2908 error = EBUSY;
2909 else if ((object = atomic_load_ptr(&m->object)) != NULL) {
2910 /*
2911 * The page is relocated if and only if it could be
2912 * laundered or reclaimed by the page daemon.
2913 */
2914 VM_OBJECT_WLOCK(object);
2915 /* Don't care: PG_NODUMP, PG_ZERO. */
2916 if (m->object != object ||
2917 ((object->flags & OBJ_SWAP) == 0 &&
2918 object->type != OBJT_VNODE))
2919 error = EINVAL;
2920 else if (object->memattr != VM_MEMATTR_DEFAULT)
2921 error = EINVAL;
2922 else if (vm_page_queue(m) != PQ_NONE &&
2923 vm_page_tryxbusy(m) != 0) {
2924 if (vm_page_wired(m)) {
2925 vm_page_xunbusy(m);
2926 error = EBUSY;
2927 goto unlock;
2928 }
2929 KASSERT(pmap_page_get_memattr(m) ==
2930 VM_MEMATTR_DEFAULT,
2931 ("page %p has an unexpected memattr", m));
2932 KASSERT(m->oflags == 0,
2933 ("page %p has unexpected oflags", m));
2934 /* Don't care: PGA_NOSYNC. */
2935 if (!vm_page_none_valid(m)) {
2936 /*
2937 * First, try to allocate a new page
2938 * that is above "high". Failing
2939 * that, try to allocate a new page
2940 * that is below "m_run". Allocate
2941 * the new page between the end of
2942 * "m_run" and "high" only as a last
2943 * resort.
2944 */
2945 req = req_class;
2946 if ((m->flags & PG_NODUMP) != 0)
2947 req |= VM_ALLOC_NODUMP;
2948 if (trunc_page(high) !=
2949 ~(vm_paddr_t)PAGE_MASK) {
2950 m_new =
2951 vm_page_alloc_noobj_contig(
2952 req, 1, round_page(high),
2953 ~(vm_paddr_t)0, PAGE_SIZE,
2954 0, VM_MEMATTR_DEFAULT);
2955 } else
2956 m_new = NULL;
2957 if (m_new == NULL) {
2958 pa = VM_PAGE_TO_PHYS(m_run);
2959 m_new =
2960 vm_page_alloc_noobj_contig(
2961 req, 1, 0, pa - 1,
2962 PAGE_SIZE, 0,
2963 VM_MEMATTR_DEFAULT);
2964 }
2965 if (m_new == NULL) {
2966 pa += ptoa(npages);
2967 m_new =
2968 vm_page_alloc_noobj_contig(
2969 req, 1, pa, high, PAGE_SIZE,
2970 0, VM_MEMATTR_DEFAULT);
2971 }
2972 if (m_new == NULL) {
2973 vm_page_xunbusy(m);
2974 error = ENOMEM;
2975 goto unlock;
2976 }
2977
2978 /*
2979 * Unmap the page and check for new
2980 * wirings that may have been acquired
2981 * through a pmap lookup.
2982 */
2983 if (object->ref_count != 0 &&
2984 !vm_page_try_remove_all(m)) {
2985 vm_page_xunbusy(m);
2986 vm_page_free(m_new);
2987 error = EBUSY;
2988 goto unlock;
2989 }
2990
2991 /*
2992 * Replace "m" with the new page. For
2993 * vm_page_replace(), "m" must be busy
2994 * and dequeued. Finally, change "m"
2995 * as if vm_page_free() was called.
2996 */
2997 m_new->a.flags = m->a.flags &
2998 ~PGA_QUEUE_STATE_MASK;
2999 KASSERT(m_new->oflags == VPO_UNMANAGED,
3000 ("page %p is managed", m_new));
3001 m_new->oflags = 0;
3002 pmap_copy_page(m, m_new);
3003 m_new->valid = m->valid;
3004 m_new->dirty = m->dirty;
3005 m->flags &= ~PG_ZERO;
3006 vm_page_dequeue(m);
3007 if (vm_page_replace_hold(m_new, object,
3008 m->pindex, m) &&
3009 vm_page_free_prep(m))
3010 SLIST_INSERT_HEAD(&free, m,
3011 plinks.s.ss);
3012
3013 /*
3014 * The new page must be deactivated
3015 * before the object is unlocked.
3016 */
3017 vm_page_deactivate(m_new);
3018 } else {
3019 m->flags &= ~PG_ZERO;
3020 vm_page_dequeue(m);
3021 if (vm_page_free_prep(m))
3022 SLIST_INSERT_HEAD(&free, m,
3023 plinks.s.ss);
3024 KASSERT(m->dirty == 0,
3025 ("page %p is dirty", m));
3026 }
3027 } else
3028 error = EBUSY;
3029 unlock:
3030 VM_OBJECT_WUNLOCK(object);
3031 } else {
3032 MPASS(vm_page_domain(m) == domain);
3033 vmd = VM_DOMAIN(domain);
3034 vm_domain_free_lock(vmd);
3035 order = m->order;
3036 if (order < VM_NFREEORDER) {
3037 /*
3038 * The page is enqueued in the physical memory
3039 * allocator's free page queues. Moreover, it
3040 * is the first page in a power-of-two-sized
3041 * run of contiguous free pages. Jump ahead
3042 * to the last page within that run, and
3043 * continue from there.
3044 */
3045 m += (1 << order) - 1;
3046 }
3047 #if VM_NRESERVLEVEL > 0
3048 else if (vm_reserv_is_page_free(m))
3049 order = 0;
3050 #endif
3051 vm_domain_free_unlock(vmd);
3052 if (order == VM_NFREEORDER)
3053 error = EINVAL;
3054 }
3055 }
3056 if ((m = SLIST_FIRST(&free)) != NULL) {
3057 int cnt;
3058
3059 vmd = VM_DOMAIN(domain);
3060 cnt = 0;
3061 vm_domain_free_lock(vmd);
3062 do {
3063 MPASS(vm_page_domain(m) == domain);
3064 SLIST_REMOVE_HEAD(&free, plinks.s.ss);
3065 vm_phys_free_pages(m, 0);
3066 cnt++;
3067 } while ((m = SLIST_FIRST(&free)) != NULL);
3068 vm_domain_free_unlock(vmd);
3069 vm_domain_freecnt_inc(vmd, cnt);
3070 }
3071 return (error);
3072 }
3073
3074 #define NRUNS 16
3075
3076 #define RUN_INDEX(count, nruns) ((count) % (nruns))
3077
3078 #define MIN_RECLAIM 8
3079
3080 /*
3081 * vm_page_reclaim_contig:
3082 *
3083 * Reclaim allocated, contiguous physical memory satisfying the specified
3084 * conditions by relocating the virtual pages using that physical memory.
3085 * Returns 0 if reclamation is successful, ERANGE if the specified domain
3086 * can't possibly satisfy the reclamation request, or ENOMEM if not
3087 * currently able to reclaim the requested number of pages. Since
3088 * relocation requires the allocation of physical pages, reclamation may
3089 * fail with ENOMEM due to a shortage of free pages. When reclamation
3090 * fails in this manner, callers are expected to perform vm_wait() before
3091 * retrying a failed allocation operation, e.g., vm_page_alloc_contig().
3092 *
3093 * The caller must always specify an allocation class through "req".
3094 *
3095 * allocation classes:
3096 * VM_ALLOC_NORMAL normal process request
3097 * VM_ALLOC_SYSTEM system *really* needs a page
3098 * VM_ALLOC_INTERRUPT interrupt time request
3099 *
3100 * The optional allocation flags are ignored.
3101 *
3102 * "npages" must be greater than zero. Both "alignment" and "boundary"
3103 * must be a power of two.
3104 */
3105 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)3106 vm_page_reclaim_contig_domain_ext(int domain, int req, u_long npages,
3107 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
3108 int desired_runs)
3109 {
3110 struct vm_domain *vmd;
3111 vm_page_t bounds[2], m_run, _m_runs[NRUNS], *m_runs;
3112 u_long count, minalign, reclaimed;
3113 int error, i, min_reclaim, nruns, options, req_class;
3114 int segind, start_segind;
3115 int ret;
3116
3117 KASSERT(npages > 0, ("npages is 0"));
3118 KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
3119 KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
3120
3121 ret = ENOMEM;
3122
3123 /*
3124 * If the caller wants to reclaim multiple runs, try to allocate
3125 * space to store the runs. If that fails, fall back to the old
3126 * behavior of just reclaiming MIN_RECLAIM pages.
3127 */
3128 if (desired_runs > 1)
3129 m_runs = malloc((NRUNS + desired_runs) * sizeof(*m_runs),
3130 M_TEMP, M_NOWAIT);
3131 else
3132 m_runs = NULL;
3133
3134 if (m_runs == NULL) {
3135 m_runs = _m_runs;
3136 nruns = NRUNS;
3137 } else {
3138 nruns = NRUNS + desired_runs - 1;
3139 }
3140 min_reclaim = MAX(desired_runs * npages, MIN_RECLAIM);
3141
3142 /*
3143 * The caller will attempt an allocation after some runs have been
3144 * reclaimed and added to the vm_phys buddy lists. Due to limitations
3145 * of vm_phys_alloc_contig(), round up the requested length to the next
3146 * power of two or maximum chunk size, and ensure that each run is
3147 * suitably aligned.
3148 */
3149 minalign = 1ul << imin(flsl(npages - 1), VM_NFREEORDER - 1);
3150 npages = roundup2(npages, minalign);
3151 if (alignment < ptoa(minalign))
3152 alignment = ptoa(minalign);
3153
3154 /*
3155 * The page daemon is allowed to dig deeper into the free page list.
3156 */
3157 req_class = req & VM_ALLOC_CLASS_MASK;
3158 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT)
3159 req_class = VM_ALLOC_SYSTEM;
3160
3161 start_segind = vm_phys_lookup_segind(low);
3162
3163 /*
3164 * Return if the number of free pages cannot satisfy the requested
3165 * allocation.
3166 */
3167 vmd = VM_DOMAIN(domain);
3168 count = vmd->vmd_free_count;
3169 if (count < npages + vmd->vmd_free_reserved || (count < npages +
3170 vmd->vmd_interrupt_free_min && req_class == VM_ALLOC_SYSTEM) ||
3171 (count < npages && req_class == VM_ALLOC_INTERRUPT))
3172 goto done;
3173
3174 /*
3175 * Scan up to three times, relaxing the restrictions ("options") on
3176 * the reclamation of reservations and superpages each time.
3177 */
3178 for (options = VPSC_NORESERV;;) {
3179 bool phys_range_exists = false;
3180
3181 /*
3182 * Find the highest runs that satisfy the given constraints
3183 * and restrictions, and record them in "m_runs".
3184 */
3185 count = 0;
3186 segind = start_segind;
3187 while ((segind = vm_phys_find_range(bounds, segind, domain,
3188 npages, low, high)) != -1) {
3189 phys_range_exists = true;
3190 while ((m_run = vm_page_scan_contig(npages, bounds[0],
3191 bounds[1], alignment, boundary, options))) {
3192 bounds[0] = m_run + npages;
3193 m_runs[RUN_INDEX(count, nruns)] = m_run;
3194 count++;
3195 }
3196 segind++;
3197 }
3198
3199 if (!phys_range_exists) {
3200 ret = ERANGE;
3201 goto done;
3202 }
3203
3204 /*
3205 * Reclaim the highest runs in LIFO (descending) order until
3206 * the number of reclaimed pages, "reclaimed", is at least
3207 * "min_reclaim". Reset "reclaimed" each time because each
3208 * reclamation is idempotent, and runs will (likely) recur
3209 * from one scan to the next as restrictions are relaxed.
3210 */
3211 reclaimed = 0;
3212 for (i = 0; count > 0 && i < nruns; i++) {
3213 count--;
3214 m_run = m_runs[RUN_INDEX(count, nruns)];
3215 error = vm_page_reclaim_run(req_class, domain, npages,
3216 m_run, high);
3217 if (error == 0) {
3218 reclaimed += npages;
3219 if (reclaimed >= min_reclaim) {
3220 ret = 0;
3221 goto done;
3222 }
3223 }
3224 }
3225
3226 /*
3227 * Either relax the restrictions on the next scan or return if
3228 * the last scan had no restrictions.
3229 */
3230 if (options == VPSC_NORESERV)
3231 options = VPSC_NOSUPER;
3232 else if (options == VPSC_NOSUPER)
3233 options = VPSC_ANY;
3234 else if (options == VPSC_ANY) {
3235 if (reclaimed != 0)
3236 ret = 0;
3237 goto done;
3238 }
3239 }
3240 done:
3241 if (m_runs != _m_runs)
3242 free(m_runs, M_TEMP);
3243 return (ret);
3244 }
3245
3246 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)3247 vm_page_reclaim_contig_domain(int domain, int req, u_long npages,
3248 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary)
3249 {
3250 return (vm_page_reclaim_contig_domain_ext(domain, req, npages, low, high,
3251 alignment, boundary, 1));
3252 }
3253
3254 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)3255 vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, vm_paddr_t high,
3256 u_long alignment, vm_paddr_t boundary)
3257 {
3258 struct vm_domainset_iter di;
3259 int domain, ret, status;
3260
3261 ret = ERANGE;
3262
3263 vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req);
3264 do {
3265 status = vm_page_reclaim_contig_domain(domain, req, npages, low,
3266 high, alignment, boundary);
3267 if (status == 0)
3268 return (0);
3269 else if (status == ERANGE)
3270 vm_domainset_iter_ignore(&di, domain);
3271 else {
3272 KASSERT(status == ENOMEM, ("Unrecognized error %d "
3273 "from vm_page_reclaim_contig_domain()", status));
3274 ret = ENOMEM;
3275 }
3276 } while (vm_domainset_iter_page(&di, NULL, &domain) == 0);
3277
3278 return (ret);
3279 }
3280
3281 /*
3282 * Set the domain in the appropriate page level domainset.
3283 */
3284 void
vm_domain_set(struct vm_domain * vmd)3285 vm_domain_set(struct vm_domain *vmd)
3286 {
3287
3288 mtx_lock(&vm_domainset_lock);
3289 if (!vmd->vmd_minset && vm_paging_min(vmd)) {
3290 vmd->vmd_minset = 1;
3291 DOMAINSET_SET(vmd->vmd_domain, &vm_min_domains);
3292 }
3293 if (!vmd->vmd_severeset && vm_paging_severe(vmd)) {
3294 vmd->vmd_severeset = 1;
3295 DOMAINSET_SET(vmd->vmd_domain, &vm_severe_domains);
3296 }
3297 mtx_unlock(&vm_domainset_lock);
3298 }
3299
3300 /*
3301 * Clear the domain from the appropriate page level domainset.
3302 */
3303 void
vm_domain_clear(struct vm_domain * vmd)3304 vm_domain_clear(struct vm_domain *vmd)
3305 {
3306
3307 mtx_lock(&vm_domainset_lock);
3308 if (vmd->vmd_minset && !vm_paging_min(vmd)) {
3309 vmd->vmd_minset = 0;
3310 DOMAINSET_CLR(vmd->vmd_domain, &vm_min_domains);
3311 if (vm_min_waiters != 0) {
3312 vm_min_waiters = 0;
3313 wakeup(&vm_min_domains);
3314 }
3315 }
3316 if (vmd->vmd_severeset && !vm_paging_severe(vmd)) {
3317 vmd->vmd_severeset = 0;
3318 DOMAINSET_CLR(vmd->vmd_domain, &vm_severe_domains);
3319 if (vm_severe_waiters != 0) {
3320 vm_severe_waiters = 0;
3321 wakeup(&vm_severe_domains);
3322 }
3323 }
3324
3325 /*
3326 * If pageout daemon needs pages, then tell it that there are
3327 * some free.
3328 */
3329 if (vmd->vmd_pageout_pages_needed &&
3330 vmd->vmd_free_count >= vmd->vmd_pageout_free_min) {
3331 wakeup(&vmd->vmd_pageout_pages_needed);
3332 vmd->vmd_pageout_pages_needed = 0;
3333 }
3334
3335 /* See comments in vm_wait_doms(). */
3336 if (vm_pageproc_waiters) {
3337 vm_pageproc_waiters = 0;
3338 wakeup(&vm_pageproc_waiters);
3339 }
3340 mtx_unlock(&vm_domainset_lock);
3341 }
3342
3343 /*
3344 * Wait for free pages to exceed the min threshold globally.
3345 */
3346 void
vm_wait_min(void)3347 vm_wait_min(void)
3348 {
3349
3350 mtx_lock(&vm_domainset_lock);
3351 while (vm_page_count_min()) {
3352 vm_min_waiters++;
3353 msleep(&vm_min_domains, &vm_domainset_lock, PVM, "vmwait", 0);
3354 }
3355 mtx_unlock(&vm_domainset_lock);
3356 }
3357
3358 /*
3359 * Wait for free pages to exceed the severe threshold globally.
3360 */
3361 void
vm_wait_severe(void)3362 vm_wait_severe(void)
3363 {
3364
3365 mtx_lock(&vm_domainset_lock);
3366 while (vm_page_count_severe()) {
3367 vm_severe_waiters++;
3368 msleep(&vm_severe_domains, &vm_domainset_lock, PVM,
3369 "vmwait", 0);
3370 }
3371 mtx_unlock(&vm_domainset_lock);
3372 }
3373
3374 u_int
vm_wait_count(void)3375 vm_wait_count(void)
3376 {
3377
3378 return (vm_severe_waiters + vm_min_waiters + vm_pageproc_waiters);
3379 }
3380
3381 int
vm_wait_doms(const domainset_t * wdoms,int mflags)3382 vm_wait_doms(const domainset_t *wdoms, int mflags)
3383 {
3384 int error;
3385
3386 error = 0;
3387
3388 /*
3389 * We use racey wakeup synchronization to avoid expensive global
3390 * locking for the pageproc when sleeping with a non-specific vm_wait.
3391 * To handle this, we only sleep for one tick in this instance. It
3392 * is expected that most allocations for the pageproc will come from
3393 * kmem or vm_page_grab* which will use the more specific and
3394 * race-free vm_wait_domain().
3395 */
3396 if (curproc == pageproc) {
3397 mtx_lock(&vm_domainset_lock);
3398 vm_pageproc_waiters++;
3399 error = msleep(&vm_pageproc_waiters, &vm_domainset_lock,
3400 PVM | PDROP | mflags, "pageprocwait", 1);
3401 } else {
3402 /*
3403 * XXX Ideally we would wait only until the allocation could
3404 * be satisfied. This condition can cause new allocators to
3405 * consume all freed pages while old allocators wait.
3406 */
3407 mtx_lock(&vm_domainset_lock);
3408 if (vm_page_count_min_set(wdoms)) {
3409 if (pageproc == NULL)
3410 panic("vm_wait in early boot");
3411 vm_min_waiters++;
3412 error = msleep(&vm_min_domains, &vm_domainset_lock,
3413 PVM | PDROP | mflags, "vmwait", 0);
3414 } else
3415 mtx_unlock(&vm_domainset_lock);
3416 }
3417 return (error);
3418 }
3419
3420 /*
3421 * vm_wait_domain:
3422 *
3423 * Sleep until free pages are available for allocation.
3424 * - Called in various places after failed memory allocations.
3425 */
3426 void
vm_wait_domain(int domain)3427 vm_wait_domain(int domain)
3428 {
3429 struct vm_domain *vmd;
3430 domainset_t wdom;
3431
3432 vmd = VM_DOMAIN(domain);
3433 vm_domain_free_assert_unlocked(vmd);
3434
3435 if (curproc == pageproc) {
3436 mtx_lock(&vm_domainset_lock);
3437 if (vmd->vmd_free_count < vmd->vmd_pageout_free_min) {
3438 vmd->vmd_pageout_pages_needed = 1;
3439 msleep(&vmd->vmd_pageout_pages_needed,
3440 &vm_domainset_lock, PDROP | PSWP, "VMWait", 0);
3441 } else
3442 mtx_unlock(&vm_domainset_lock);
3443 } else {
3444 DOMAINSET_ZERO(&wdom);
3445 DOMAINSET_SET(vmd->vmd_domain, &wdom);
3446 vm_wait_doms(&wdom, 0);
3447 }
3448 }
3449
3450 static int
vm_wait_flags(vm_object_t obj,int mflags)3451 vm_wait_flags(vm_object_t obj, int mflags)
3452 {
3453 struct domainset *d;
3454
3455 d = NULL;
3456
3457 /*
3458 * Carefully fetch pointers only once: the struct domainset
3459 * itself is ummutable but the pointer might change.
3460 */
3461 if (obj != NULL)
3462 d = obj->domain.dr_policy;
3463 if (d == NULL)
3464 d = curthread->td_domain.dr_policy;
3465
3466 return (vm_wait_doms(&d->ds_mask, mflags));
3467 }
3468
3469 /*
3470 * vm_wait:
3471 *
3472 * Sleep until free pages are available for allocation in the
3473 * affinity domains of the obj. If obj is NULL, the domain set
3474 * for the calling thread is used.
3475 * Called in various places after failed memory allocations.
3476 */
3477 void
vm_wait(vm_object_t obj)3478 vm_wait(vm_object_t obj)
3479 {
3480 (void)vm_wait_flags(obj, 0);
3481 }
3482
3483 int
vm_wait_intr(vm_object_t obj)3484 vm_wait_intr(vm_object_t obj)
3485 {
3486 return (vm_wait_flags(obj, PCATCH));
3487 }
3488
3489 /*
3490 * vm_domain_alloc_fail:
3491 *
3492 * Called when a page allocation function fails. Informs the
3493 * pagedaemon and performs the requested wait. Requires the
3494 * domain_free and object lock on entry. Returns with the
3495 * object lock held and free lock released. Returns an error when
3496 * retry is necessary.
3497 *
3498 */
3499 static int
vm_domain_alloc_fail(struct vm_domain * vmd,vm_object_t object,int req)3500 vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, int req)
3501 {
3502
3503 vm_domain_free_assert_unlocked(vmd);
3504
3505 atomic_add_int(&vmd->vmd_pageout_deficit,
3506 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1));
3507 if (req & (VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL)) {
3508 if (object != NULL)
3509 VM_OBJECT_WUNLOCK(object);
3510 vm_wait_domain(vmd->vmd_domain);
3511 if (object != NULL)
3512 VM_OBJECT_WLOCK(object);
3513 if (req & VM_ALLOC_WAITOK)
3514 return (EAGAIN);
3515 }
3516
3517 return (0);
3518 }
3519
3520 /*
3521 * vm_waitpfault:
3522 *
3523 * Sleep until free pages are available for allocation.
3524 * - Called only in vm_fault so that processes page faulting
3525 * can be easily tracked.
3526 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing
3527 * processes will be able to grab memory first. Do not change
3528 * this balance without careful testing first.
3529 */
3530 void
vm_waitpfault(struct domainset * dset,int timo)3531 vm_waitpfault(struct domainset *dset, int timo)
3532 {
3533
3534 /*
3535 * XXX Ideally we would wait only until the allocation could
3536 * be satisfied. This condition can cause new allocators to
3537 * consume all freed pages while old allocators wait.
3538 */
3539 mtx_lock(&vm_domainset_lock);
3540 if (vm_page_count_min_set(&dset->ds_mask)) {
3541 vm_min_waiters++;
3542 msleep(&vm_min_domains, &vm_domainset_lock, PUSER | PDROP,
3543 "pfault", timo);
3544 } else
3545 mtx_unlock(&vm_domainset_lock);
3546 }
3547
3548 static struct vm_pagequeue *
_vm_page_pagequeue(vm_page_t m,uint8_t queue)3549 _vm_page_pagequeue(vm_page_t m, uint8_t queue)
3550 {
3551
3552 return (&vm_pagequeue_domain(m)->vmd_pagequeues[queue]);
3553 }
3554
3555 #ifdef INVARIANTS
3556 static struct vm_pagequeue *
vm_page_pagequeue(vm_page_t m)3557 vm_page_pagequeue(vm_page_t m)
3558 {
3559
3560 return (_vm_page_pagequeue(m, vm_page_astate_load(m).queue));
3561 }
3562 #endif
3563
3564 static __always_inline bool
vm_page_pqstate_fcmpset(vm_page_t m,vm_page_astate_t * old,vm_page_astate_t new)3565 vm_page_pqstate_fcmpset(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new)
3566 {
3567 vm_page_astate_t tmp;
3568
3569 tmp = *old;
3570 do {
3571 if (__predict_true(vm_page_astate_fcmpset(m, old, new)))
3572 return (true);
3573 counter_u64_add(pqstate_commit_retries, 1);
3574 } while (old->_bits == tmp._bits);
3575
3576 return (false);
3577 }
3578
3579 /*
3580 * Do the work of committing a queue state update that moves the page out of
3581 * its current queue.
3582 */
3583 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)3584 _vm_page_pqstate_commit_dequeue(struct vm_pagequeue *pq, vm_page_t m,
3585 vm_page_astate_t *old, vm_page_astate_t new)
3586 {
3587 vm_page_t next;
3588
3589 vm_pagequeue_assert_locked(pq);
3590 KASSERT(vm_page_pagequeue(m) == pq,
3591 ("%s: queue %p does not match page %p", __func__, pq, m));
3592 KASSERT(old->queue != PQ_NONE && new.queue != old->queue,
3593 ("%s: invalid queue indices %d %d",
3594 __func__, old->queue, new.queue));
3595
3596 /*
3597 * Once the queue index of the page changes there is nothing
3598 * synchronizing with further updates to the page's physical
3599 * queue state. Therefore we must speculatively remove the page
3600 * from the queue now and be prepared to roll back if the queue
3601 * state update fails. If the page is not physically enqueued then
3602 * we just update its queue index.
3603 */
3604 if ((old->flags & PGA_ENQUEUED) != 0) {
3605 new.flags &= ~PGA_ENQUEUED;
3606 next = TAILQ_NEXT(m, plinks.q);
3607 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q);
3608 vm_pagequeue_cnt_dec(pq);
3609 if (!vm_page_pqstate_fcmpset(m, old, new)) {
3610 if (next == NULL)
3611 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q);
3612 else
3613 TAILQ_INSERT_BEFORE(next, m, plinks.q);
3614 vm_pagequeue_cnt_inc(pq);
3615 return (false);
3616 } else {
3617 return (true);
3618 }
3619 } else {
3620 return (vm_page_pqstate_fcmpset(m, old, new));
3621 }
3622 }
3623
3624 static bool
vm_page_pqstate_commit_dequeue(vm_page_t m,vm_page_astate_t * old,vm_page_astate_t new)3625 vm_page_pqstate_commit_dequeue(vm_page_t m, vm_page_astate_t *old,
3626 vm_page_astate_t new)
3627 {
3628 struct vm_pagequeue *pq;
3629 vm_page_astate_t as;
3630 bool ret;
3631
3632 pq = _vm_page_pagequeue(m, old->queue);
3633
3634 /*
3635 * The queue field and PGA_ENQUEUED flag are stable only so long as the
3636 * corresponding page queue lock is held.
3637 */
3638 vm_pagequeue_lock(pq);
3639 as = vm_page_astate_load(m);
3640 if (__predict_false(as._bits != old->_bits)) {
3641 *old = as;
3642 ret = false;
3643 } else {
3644 ret = _vm_page_pqstate_commit_dequeue(pq, m, old, new);
3645 }
3646 vm_pagequeue_unlock(pq);
3647 return (ret);
3648 }
3649
3650 /*
3651 * Commit a queue state update that enqueues or requeues a page.
3652 */
3653 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)3654 _vm_page_pqstate_commit_requeue(struct vm_pagequeue *pq, vm_page_t m,
3655 vm_page_astate_t *old, vm_page_astate_t new)
3656 {
3657 struct vm_domain *vmd;
3658
3659 vm_pagequeue_assert_locked(pq);
3660 KASSERT(old->queue != PQ_NONE && new.queue == old->queue,
3661 ("%s: invalid queue indices %d %d",
3662 __func__, old->queue, new.queue));
3663
3664 new.flags |= PGA_ENQUEUED;
3665 if (!vm_page_pqstate_fcmpset(m, old, new))
3666 return (false);
3667
3668 if ((old->flags & PGA_ENQUEUED) != 0)
3669 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q);
3670 else
3671 vm_pagequeue_cnt_inc(pq);
3672
3673 /*
3674 * Give PGA_REQUEUE_HEAD precedence over PGA_REQUEUE. In particular, if
3675 * both flags are set in close succession, only PGA_REQUEUE_HEAD will be
3676 * applied, even if it was set first.
3677 */
3678 if ((old->flags & PGA_REQUEUE_HEAD) != 0) {
3679 vmd = vm_pagequeue_domain(m);
3680 KASSERT(pq == &vmd->vmd_pagequeues[PQ_INACTIVE],
3681 ("%s: invalid page queue for page %p", __func__, m));
3682 TAILQ_INSERT_BEFORE(&vmd->vmd_inacthead, m, plinks.q);
3683 } else {
3684 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q);
3685 }
3686 return (true);
3687 }
3688
3689 /*
3690 * Commit a queue state update that encodes a request for a deferred queue
3691 * operation.
3692 */
3693 static bool
vm_page_pqstate_commit_request(vm_page_t m,vm_page_astate_t * old,vm_page_astate_t new)3694 vm_page_pqstate_commit_request(vm_page_t m, vm_page_astate_t *old,
3695 vm_page_astate_t new)
3696 {
3697
3698 KASSERT(old->queue == new.queue || new.queue != PQ_NONE,
3699 ("%s: invalid state, queue %d flags %x",
3700 __func__, new.queue, new.flags));
3701
3702 if (old->_bits != new._bits &&
3703 !vm_page_pqstate_fcmpset(m, old, new))
3704 return (false);
3705 vm_page_pqbatch_submit(m, new.queue);
3706 return (true);
3707 }
3708
3709 /*
3710 * A generic queue state update function. This handles more cases than the
3711 * specialized functions above.
3712 */
3713 bool
vm_page_pqstate_commit(vm_page_t m,vm_page_astate_t * old,vm_page_astate_t new)3714 vm_page_pqstate_commit(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new)
3715 {
3716
3717 if (old->_bits == new._bits)
3718 return (true);
3719
3720 if (old->queue != PQ_NONE && new.queue != old->queue) {
3721 if (!vm_page_pqstate_commit_dequeue(m, old, new))
3722 return (false);
3723 if (new.queue != PQ_NONE)
3724 vm_page_pqbatch_submit(m, new.queue);
3725 } else {
3726 if (!vm_page_pqstate_fcmpset(m, old, new))
3727 return (false);
3728 if (new.queue != PQ_NONE &&
3729 ((new.flags & ~old->flags) & PGA_QUEUE_OP_MASK) != 0)
3730 vm_page_pqbatch_submit(m, new.queue);
3731 }
3732 return (true);
3733 }
3734
3735 /*
3736 * Apply deferred queue state updates to a page.
3737 */
3738 static inline void
vm_pqbatch_process_page(struct vm_pagequeue * pq,vm_page_t m,uint8_t queue)3739 vm_pqbatch_process_page(struct vm_pagequeue *pq, vm_page_t m, uint8_t queue)
3740 {
3741 vm_page_astate_t new, old;
3742
3743 CRITICAL_ASSERT(curthread);
3744 vm_pagequeue_assert_locked(pq);
3745 KASSERT(queue < PQ_COUNT,
3746 ("%s: invalid queue index %d", __func__, queue));
3747 KASSERT(pq == _vm_page_pagequeue(m, queue),
3748 ("%s: page %p does not belong to queue %p", __func__, m, pq));
3749
3750 for (old = vm_page_astate_load(m);;) {
3751 if (__predict_false(old.queue != queue ||
3752 (old.flags & PGA_QUEUE_OP_MASK) == 0)) {
3753 counter_u64_add(queue_nops, 1);
3754 break;
3755 }
3756 KASSERT((m->oflags & VPO_UNMANAGED) == 0,
3757 ("%s: page %p is unmanaged", __func__, m));
3758
3759 new = old;
3760 if ((old.flags & PGA_DEQUEUE) != 0) {
3761 new.flags &= ~PGA_QUEUE_OP_MASK;
3762 new.queue = PQ_NONE;
3763 if (__predict_true(_vm_page_pqstate_commit_dequeue(pq,
3764 m, &old, new))) {
3765 counter_u64_add(queue_ops, 1);
3766 break;
3767 }
3768 } else {
3769 new.flags &= ~(PGA_REQUEUE | PGA_REQUEUE_HEAD);
3770 if (__predict_true(_vm_page_pqstate_commit_requeue(pq,
3771 m, &old, new))) {
3772 counter_u64_add(queue_ops, 1);
3773 break;
3774 }
3775 }
3776 }
3777 }
3778
3779 static void
vm_pqbatch_process(struct vm_pagequeue * pq,struct vm_batchqueue * bq,uint8_t queue)3780 vm_pqbatch_process(struct vm_pagequeue *pq, struct vm_batchqueue *bq,
3781 uint8_t queue)
3782 {
3783 int i;
3784
3785 for (i = 0; i < bq->bq_cnt; i++)
3786 vm_pqbatch_process_page(pq, bq->bq_pa[i], queue);
3787 vm_batchqueue_init(bq);
3788 }
3789
3790 /*
3791 * vm_page_pqbatch_submit: [ internal use only ]
3792 *
3793 * Enqueue a page in the specified page queue's batched work queue.
3794 * The caller must have encoded the requested operation in the page
3795 * structure's a.flags field.
3796 */
3797 void
vm_page_pqbatch_submit(vm_page_t m,uint8_t queue)3798 vm_page_pqbatch_submit(vm_page_t m, uint8_t queue)
3799 {
3800 struct vm_batchqueue *bq;
3801 struct vm_pagequeue *pq;
3802 int domain, slots_remaining;
3803
3804 KASSERT(queue < PQ_COUNT, ("invalid queue %d", queue));
3805
3806 domain = vm_page_domain(m);
3807 critical_enter();
3808 bq = DPCPU_PTR(pqbatch[domain][queue]);
3809 slots_remaining = vm_batchqueue_insert(bq, m);
3810 if (slots_remaining > (VM_BATCHQUEUE_SIZE >> 1)) {
3811 /* keep building the bq */
3812 critical_exit();
3813 return;
3814 } else if (slots_remaining > 0 ) {
3815 /* Try to process the bq if we can get the lock */
3816 pq = &VM_DOMAIN(domain)->vmd_pagequeues[queue];
3817 if (vm_pagequeue_trylock(pq)) {
3818 vm_pqbatch_process(pq, bq, queue);
3819 vm_pagequeue_unlock(pq);
3820 }
3821 critical_exit();
3822 return;
3823 }
3824 critical_exit();
3825
3826 /* if we make it here, the bq is full so wait for the lock */
3827
3828 pq = &VM_DOMAIN(domain)->vmd_pagequeues[queue];
3829 vm_pagequeue_lock(pq);
3830 critical_enter();
3831 bq = DPCPU_PTR(pqbatch[domain][queue]);
3832 vm_pqbatch_process(pq, bq, queue);
3833 vm_pqbatch_process_page(pq, m, queue);
3834 vm_pagequeue_unlock(pq);
3835 critical_exit();
3836 }
3837
3838 /*
3839 * vm_page_pqbatch_drain: [ internal use only ]
3840 *
3841 * Force all per-CPU page queue batch queues to be drained. This is
3842 * intended for use in severe memory shortages, to ensure that pages
3843 * do not remain stuck in the batch queues.
3844 */
3845 void
vm_page_pqbatch_drain(void)3846 vm_page_pqbatch_drain(void)
3847 {
3848 struct thread *td;
3849 struct vm_domain *vmd;
3850 struct vm_pagequeue *pq;
3851 int cpu, domain, queue;
3852
3853 td = curthread;
3854 CPU_FOREACH(cpu) {
3855 thread_lock(td);
3856 sched_bind(td, cpu);
3857 thread_unlock(td);
3858
3859 for (domain = 0; domain < vm_ndomains; domain++) {
3860 vmd = VM_DOMAIN(domain);
3861 for (queue = 0; queue < PQ_COUNT; queue++) {
3862 pq = &vmd->vmd_pagequeues[queue];
3863 vm_pagequeue_lock(pq);
3864 critical_enter();
3865 vm_pqbatch_process(pq,
3866 DPCPU_PTR(pqbatch[domain][queue]), queue);
3867 critical_exit();
3868 vm_pagequeue_unlock(pq);
3869 }
3870 }
3871 }
3872 thread_lock(td);
3873 sched_unbind(td);
3874 thread_unlock(td);
3875 }
3876
3877 /*
3878 * vm_page_dequeue_deferred: [ internal use only ]
3879 *
3880 * Request removal of the given page from its current page
3881 * queue. Physical removal from the queue may be deferred
3882 * indefinitely.
3883 */
3884 void
vm_page_dequeue_deferred(vm_page_t m)3885 vm_page_dequeue_deferred(vm_page_t m)
3886 {
3887 vm_page_astate_t new, old;
3888
3889 old = vm_page_astate_load(m);
3890 do {
3891 if (old.queue == PQ_NONE) {
3892 KASSERT((old.flags & PGA_QUEUE_STATE_MASK) == 0,
3893 ("%s: page %p has unexpected queue state",
3894 __func__, m));
3895 break;
3896 }
3897 new = old;
3898 new.flags |= PGA_DEQUEUE;
3899 } while (!vm_page_pqstate_commit_request(m, &old, new));
3900 }
3901
3902 /*
3903 * vm_page_dequeue:
3904 *
3905 * Remove the page from whichever page queue it's in, if any, before
3906 * returning.
3907 */
3908 void
vm_page_dequeue(vm_page_t m)3909 vm_page_dequeue(vm_page_t m)
3910 {
3911 vm_page_astate_t new, old;
3912
3913 old = vm_page_astate_load(m);
3914 do {
3915 if (old.queue == PQ_NONE) {
3916 KASSERT((old.flags & PGA_QUEUE_STATE_MASK) == 0,
3917 ("%s: page %p has unexpected queue state",
3918 __func__, m));
3919 break;
3920 }
3921 new = old;
3922 new.flags &= ~PGA_QUEUE_OP_MASK;
3923 new.queue = PQ_NONE;
3924 } while (!vm_page_pqstate_commit_dequeue(m, &old, new));
3925
3926 }
3927
3928 /*
3929 * Schedule the given page for insertion into the specified page queue.
3930 * Physical insertion of the page may be deferred indefinitely.
3931 */
3932 static void
vm_page_enqueue(vm_page_t m,uint8_t queue)3933 vm_page_enqueue(vm_page_t m, uint8_t queue)
3934 {
3935
3936 KASSERT(m->a.queue == PQ_NONE &&
3937 (m->a.flags & PGA_QUEUE_STATE_MASK) == 0,
3938 ("%s: page %p is already enqueued", __func__, m));
3939 KASSERT(m->ref_count > 0,
3940 ("%s: page %p does not carry any references", __func__, m));
3941
3942 m->a.queue = queue;
3943 if ((m->a.flags & PGA_REQUEUE) == 0)
3944 vm_page_aflag_set(m, PGA_REQUEUE);
3945 vm_page_pqbatch_submit(m, queue);
3946 }
3947
3948 /*
3949 * vm_page_free_prep:
3950 *
3951 * Prepares the given page to be put on the free list,
3952 * disassociating it from any VM object. The caller may return
3953 * the page to the free list only if this function returns true.
3954 *
3955 * The object, if it exists, must be locked, and then the page must
3956 * be xbusy. Otherwise the page must be not busied. A managed
3957 * page must be unmapped.
3958 */
3959 static bool
vm_page_free_prep(vm_page_t m)3960 vm_page_free_prep(vm_page_t m)
3961 {
3962
3963 /*
3964 * Synchronize with threads that have dropped a reference to this
3965 * page.
3966 */
3967 atomic_thread_fence_acq();
3968
3969 #if defined(DIAGNOSTIC) && defined(PHYS_TO_DMAP)
3970 if (PMAP_HAS_DMAP && (m->flags & PG_ZERO) != 0) {
3971 uint64_t *p;
3972 int i;
3973 p = (uint64_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m));
3974 for (i = 0; i < PAGE_SIZE / sizeof(uint64_t); i++, p++)
3975 KASSERT(*p == 0, ("vm_page_free_prep %p PG_ZERO %d %jx",
3976 m, i, (uintmax_t)*p));
3977 }
3978 #endif
3979 if ((m->oflags & VPO_UNMANAGED) == 0) {
3980 KASSERT(!pmap_page_is_mapped(m),
3981 ("vm_page_free_prep: freeing mapped page %p", m));
3982 KASSERT((m->a.flags & (PGA_EXECUTABLE | PGA_WRITEABLE)) == 0,
3983 ("vm_page_free_prep: mapping flags set in page %p", m));
3984 } else {
3985 KASSERT(m->a.queue == PQ_NONE,
3986 ("vm_page_free_prep: unmanaged page %p is queued", m));
3987 }
3988 VM_CNT_INC(v_tfree);
3989
3990 if (m->object != NULL) {
3991 KASSERT(((m->oflags & VPO_UNMANAGED) != 0) ==
3992 ((m->object->flags & OBJ_UNMANAGED) != 0),
3993 ("vm_page_free_prep: managed flag mismatch for page %p",
3994 m));
3995 vm_page_assert_xbusied(m);
3996
3997 /*
3998 * The object reference can be released without an atomic
3999 * operation.
4000 */
4001 KASSERT((m->flags & PG_FICTITIOUS) != 0 ||
4002 m->ref_count == VPRC_OBJREF,
4003 ("vm_page_free_prep: page %p has unexpected ref_count %u",
4004 m, m->ref_count));
4005 vm_page_object_remove(m);
4006 m->ref_count -= VPRC_OBJREF;
4007 } else
4008 vm_page_assert_unbusied(m);
4009
4010 vm_page_busy_free(m);
4011
4012 /*
4013 * If fictitious remove object association and
4014 * return.
4015 */
4016 if ((m->flags & PG_FICTITIOUS) != 0) {
4017 KASSERT(m->ref_count == 1,
4018 ("fictitious page %p is referenced", m));
4019 KASSERT(m->a.queue == PQ_NONE,
4020 ("fictitious page %p is queued", m));
4021 return (false);
4022 }
4023
4024 /*
4025 * Pages need not be dequeued before they are returned to the physical
4026 * memory allocator, but they must at least be marked for a deferred
4027 * dequeue.
4028 */
4029 if ((m->oflags & VPO_UNMANAGED) == 0)
4030 vm_page_dequeue_deferred(m);
4031
4032 m->valid = 0;
4033 vm_page_undirty(m);
4034
4035 if (m->ref_count != 0)
4036 panic("vm_page_free_prep: page %p has references", m);
4037
4038 /*
4039 * Restore the default memory attribute to the page.
4040 */
4041 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT)
4042 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT);
4043
4044 #if VM_NRESERVLEVEL > 0
4045 /*
4046 * Determine whether the page belongs to a reservation. If the page was
4047 * allocated from a per-CPU cache, it cannot belong to a reservation, so
4048 * as an optimization, we avoid the check in that case.
4049 */
4050 if ((m->flags & PG_PCPU_CACHE) == 0 && vm_reserv_free_page(m))
4051 return (false);
4052 #endif
4053
4054 return (true);
4055 }
4056
4057 /*
4058 * vm_page_free_toq:
4059 *
4060 * Returns the given page to the free list, disassociating it
4061 * from any VM object.
4062 *
4063 * The object must be locked. The page must be exclusively busied if it
4064 * belongs to an object.
4065 */
4066 static void
vm_page_free_toq(vm_page_t m)4067 vm_page_free_toq(vm_page_t m)
4068 {
4069 struct vm_domain *vmd;
4070 uma_zone_t zone;
4071
4072 if (!vm_page_free_prep(m))
4073 return;
4074
4075 vmd = vm_pagequeue_domain(m);
4076 zone = vmd->vmd_pgcache[m->pool].zone;
4077 if ((m->flags & PG_PCPU_CACHE) != 0 && zone != NULL) {
4078 uma_zfree(zone, m);
4079 return;
4080 }
4081 vm_domain_free_lock(vmd);
4082 vm_phys_free_pages(m, 0);
4083 vm_domain_free_unlock(vmd);
4084 vm_domain_freecnt_inc(vmd, 1);
4085 }
4086
4087 /*
4088 * vm_page_free_pages_toq:
4089 *
4090 * Returns a list of pages to the free list, disassociating it
4091 * from any VM object. In other words, this is equivalent to
4092 * calling vm_page_free_toq() for each page of a list of VM objects.
4093 */
4094 void
vm_page_free_pages_toq(struct spglist * free,bool update_wire_count)4095 vm_page_free_pages_toq(struct spglist *free, bool update_wire_count)
4096 {
4097 vm_page_t m;
4098 int count;
4099
4100 if (SLIST_EMPTY(free))
4101 return;
4102
4103 count = 0;
4104 while ((m = SLIST_FIRST(free)) != NULL) {
4105 count++;
4106 SLIST_REMOVE_HEAD(free, plinks.s.ss);
4107 vm_page_free_toq(m);
4108 }
4109
4110 if (update_wire_count)
4111 vm_wire_sub(count);
4112 }
4113
4114 /*
4115 * Mark this page as wired down. For managed pages, this prevents reclamation
4116 * by the page daemon, or when the containing object, if any, is destroyed.
4117 */
4118 void
vm_page_wire(vm_page_t m)4119 vm_page_wire(vm_page_t m)
4120 {
4121 u_int old;
4122
4123 #ifdef INVARIANTS
4124 if (m->object != NULL && !vm_page_busied(m) &&
4125 !vm_object_busied(m->object))
4126 VM_OBJECT_ASSERT_LOCKED(m->object);
4127 #endif
4128 KASSERT((m->flags & PG_FICTITIOUS) == 0 ||
4129 VPRC_WIRE_COUNT(m->ref_count) >= 1,
4130 ("vm_page_wire: fictitious page %p has zero wirings", m));
4131
4132 old = atomic_fetchadd_int(&m->ref_count, 1);
4133 KASSERT(VPRC_WIRE_COUNT(old) != VPRC_WIRE_COUNT_MAX,
4134 ("vm_page_wire: counter overflow for page %p", m));
4135 if (VPRC_WIRE_COUNT(old) == 0) {
4136 if ((m->oflags & VPO_UNMANAGED) == 0)
4137 vm_page_aflag_set(m, PGA_DEQUEUE);
4138 vm_wire_add(1);
4139 }
4140 }
4141
4142 /*
4143 * Attempt to wire a mapped page following a pmap lookup of that page.
4144 * This may fail if a thread is concurrently tearing down mappings of the page.
4145 * The transient failure is acceptable because it translates to the
4146 * failure of the caller pmap_extract_and_hold(), which should be then
4147 * followed by the vm_fault() fallback, see e.g. vm_fault_quick_hold_pages().
4148 */
4149 bool
vm_page_wire_mapped(vm_page_t m)4150 vm_page_wire_mapped(vm_page_t m)
4151 {
4152 u_int old;
4153
4154 old = m->ref_count;
4155 do {
4156 KASSERT(old > 0,
4157 ("vm_page_wire_mapped: wiring unreferenced page %p", m));
4158 if ((old & VPRC_BLOCKED) != 0)
4159 return (false);
4160 } while (!atomic_fcmpset_int(&m->ref_count, &old, old + 1));
4161
4162 if (VPRC_WIRE_COUNT(old) == 0) {
4163 if ((m->oflags & VPO_UNMANAGED) == 0)
4164 vm_page_aflag_set(m, PGA_DEQUEUE);
4165 vm_wire_add(1);
4166 }
4167 return (true);
4168 }
4169
4170 /*
4171 * Release a wiring reference to a managed page. If the page still belongs to
4172 * an object, update its position in the page queues to reflect the reference.
4173 * If the wiring was the last reference to the page, free the page.
4174 */
4175 static void
vm_page_unwire_managed(vm_page_t m,uint8_t nqueue,bool noreuse)4176 vm_page_unwire_managed(vm_page_t m, uint8_t nqueue, bool noreuse)
4177 {
4178 u_int old;
4179
4180 KASSERT((m->oflags & VPO_UNMANAGED) == 0,
4181 ("%s: page %p is unmanaged", __func__, m));
4182
4183 /*
4184 * Update LRU state before releasing the wiring reference.
4185 * Use a release store when updating the reference count to
4186 * synchronize with vm_page_free_prep().
4187 */
4188 old = m->ref_count;
4189 do {
4190 KASSERT(VPRC_WIRE_COUNT(old) > 0,
4191 ("vm_page_unwire: wire count underflow for page %p", m));
4192
4193 if (old > VPRC_OBJREF + 1) {
4194 /*
4195 * The page has at least one other wiring reference. An
4196 * earlier iteration of this loop may have called
4197 * vm_page_release_toq() and cleared PGA_DEQUEUE, so
4198 * re-set it if necessary.
4199 */
4200 if ((vm_page_astate_load(m).flags & PGA_DEQUEUE) == 0)
4201 vm_page_aflag_set(m, PGA_DEQUEUE);
4202 } else if (old == VPRC_OBJREF + 1) {
4203 /*
4204 * This is the last wiring. Clear PGA_DEQUEUE and
4205 * update the page's queue state to reflect the
4206 * reference. If the page does not belong to an object
4207 * (i.e., the VPRC_OBJREF bit is clear), we only need to
4208 * clear leftover queue state.
4209 */
4210 vm_page_release_toq(m, nqueue, noreuse);
4211 } else if (old == 1) {
4212 vm_page_aflag_clear(m, PGA_DEQUEUE);
4213 }
4214 } while (!atomic_fcmpset_rel_int(&m->ref_count, &old, old - 1));
4215
4216 if (VPRC_WIRE_COUNT(old) == 1) {
4217 vm_wire_sub(1);
4218 if (old == 1)
4219 vm_page_free(m);
4220 }
4221 }
4222
4223 /*
4224 * Release one wiring of the specified page, potentially allowing it to be
4225 * paged out.
4226 *
4227 * Only managed pages belonging to an object can be paged out. If the number
4228 * of wirings transitions to zero and the page is eligible for page out, then
4229 * the page is added to the specified paging queue. If the released wiring
4230 * represented the last reference to the page, the page is freed.
4231 */
4232 void
vm_page_unwire(vm_page_t m,uint8_t nqueue)4233 vm_page_unwire(vm_page_t m, uint8_t nqueue)
4234 {
4235
4236 KASSERT(nqueue < PQ_COUNT,
4237 ("vm_page_unwire: invalid queue %u request for page %p",
4238 nqueue, m));
4239
4240 if ((m->oflags & VPO_UNMANAGED) != 0) {
4241 if (vm_page_unwire_noq(m) && m->ref_count == 0)
4242 vm_page_free(m);
4243 return;
4244 }
4245 vm_page_unwire_managed(m, nqueue, false);
4246 }
4247
4248 /*
4249 * Unwire a page without (re-)inserting it into a page queue. It is up
4250 * to the caller to enqueue, requeue, or free the page as appropriate.
4251 * In most cases involving managed pages, vm_page_unwire() should be used
4252 * instead.
4253 */
4254 bool
vm_page_unwire_noq(vm_page_t m)4255 vm_page_unwire_noq(vm_page_t m)
4256 {
4257 u_int old;
4258
4259 old = vm_page_drop(m, 1);
4260 KASSERT(VPRC_WIRE_COUNT(old) != 0,
4261 ("%s: counter underflow for page %p", __func__, m));
4262 KASSERT((m->flags & PG_FICTITIOUS) == 0 || VPRC_WIRE_COUNT(old) > 1,
4263 ("%s: missing ref on fictitious page %p", __func__, m));
4264
4265 if (VPRC_WIRE_COUNT(old) > 1)
4266 return (false);
4267 if ((m->oflags & VPO_UNMANAGED) == 0)
4268 vm_page_aflag_clear(m, PGA_DEQUEUE);
4269 vm_wire_sub(1);
4270 return (true);
4271 }
4272
4273 /*
4274 * Ensure that the page ends up in the specified page queue. If the page is
4275 * active or being moved to the active queue, ensure that its act_count is
4276 * at least ACT_INIT but do not otherwise mess with it.
4277 */
4278 static __always_inline void
vm_page_mvqueue(vm_page_t m,const uint8_t nqueue,const uint16_t nflag)4279 vm_page_mvqueue(vm_page_t m, const uint8_t nqueue, const uint16_t nflag)
4280 {
4281 vm_page_astate_t old, new;
4282
4283 KASSERT(m->ref_count > 0,
4284 ("%s: page %p does not carry any references", __func__, m));
4285 KASSERT(nflag == PGA_REQUEUE || nflag == PGA_REQUEUE_HEAD,
4286 ("%s: invalid flags %x", __func__, nflag));
4287
4288 if ((m->oflags & VPO_UNMANAGED) != 0 || vm_page_wired(m))
4289 return;
4290
4291 old = vm_page_astate_load(m);
4292 do {
4293 if ((old.flags & PGA_DEQUEUE) != 0)
4294 break;
4295 new = old;
4296 new.flags &= ~PGA_QUEUE_OP_MASK;
4297 if (nqueue == PQ_ACTIVE)
4298 new.act_count = max(old.act_count, ACT_INIT);
4299 if (old.queue == nqueue) {
4300 /*
4301 * There is no need to requeue pages already in the
4302 * active queue.
4303 */
4304 if (nqueue != PQ_ACTIVE ||
4305 (old.flags & PGA_ENQUEUED) == 0)
4306 new.flags |= nflag;
4307 } else {
4308 new.flags |= nflag;
4309 new.queue = nqueue;
4310 }
4311 } while (!vm_page_pqstate_commit(m, &old, new));
4312 }
4313
4314 /*
4315 * Put the specified page on the active list (if appropriate).
4316 */
4317 void
vm_page_activate(vm_page_t m)4318 vm_page_activate(vm_page_t m)
4319 {
4320
4321 vm_page_mvqueue(m, PQ_ACTIVE, PGA_REQUEUE);
4322 }
4323
4324 /*
4325 * Move the specified page to the tail of the inactive queue, or requeue
4326 * the page if it is already in the inactive queue.
4327 */
4328 void
vm_page_deactivate(vm_page_t m)4329 vm_page_deactivate(vm_page_t m)
4330 {
4331
4332 vm_page_mvqueue(m, PQ_INACTIVE, PGA_REQUEUE);
4333 }
4334
4335 void
vm_page_deactivate_noreuse(vm_page_t m)4336 vm_page_deactivate_noreuse(vm_page_t m)
4337 {
4338
4339 vm_page_mvqueue(m, PQ_INACTIVE, PGA_REQUEUE_HEAD);
4340 }
4341
4342 /*
4343 * Put a page in the laundry, or requeue it if it is already there.
4344 */
4345 void
vm_page_launder(vm_page_t m)4346 vm_page_launder(vm_page_t m)
4347 {
4348
4349 vm_page_mvqueue(m, PQ_LAUNDRY, PGA_REQUEUE);
4350 }
4351
4352 /*
4353 * Put a page in the PQ_UNSWAPPABLE holding queue.
4354 */
4355 void
vm_page_unswappable(vm_page_t m)4356 vm_page_unswappable(vm_page_t m)
4357 {
4358
4359 VM_OBJECT_ASSERT_LOCKED(m->object);
4360 KASSERT((m->oflags & VPO_UNMANAGED) == 0,
4361 ("page %p already unswappable", m));
4362
4363 vm_page_dequeue(m);
4364 vm_page_enqueue(m, PQ_UNSWAPPABLE);
4365 }
4366
4367 /*
4368 * Release a page back to the page queues in preparation for unwiring.
4369 */
4370 static void
vm_page_release_toq(vm_page_t m,uint8_t nqueue,const bool noreuse)4371 vm_page_release_toq(vm_page_t m, uint8_t nqueue, const bool noreuse)
4372 {
4373 vm_page_astate_t old, new;
4374 uint16_t nflag;
4375
4376 /*
4377 * Use a check of the valid bits to determine whether we should
4378 * accelerate reclamation of the page. The object lock might not be
4379 * held here, in which case the check is racy. At worst we will either
4380 * accelerate reclamation of a valid page and violate LRU, or
4381 * unnecessarily defer reclamation of an invalid page.
4382 *
4383 * If we were asked to not cache the page, place it near the head of the
4384 * inactive queue so that is reclaimed sooner.
4385 */
4386 if (noreuse || vm_page_none_valid(m)) {
4387 nqueue = PQ_INACTIVE;
4388 nflag = PGA_REQUEUE_HEAD;
4389 } else {
4390 nflag = PGA_REQUEUE;
4391 }
4392
4393 old = vm_page_astate_load(m);
4394 do {
4395 new = old;
4396
4397 /*
4398 * If the page is already in the active queue and we are not
4399 * trying to accelerate reclamation, simply mark it as
4400 * referenced and avoid any queue operations.
4401 */
4402 new.flags &= ~PGA_QUEUE_OP_MASK;
4403 if (nflag != PGA_REQUEUE_HEAD && old.queue == PQ_ACTIVE &&
4404 (old.flags & PGA_ENQUEUED) != 0)
4405 new.flags |= PGA_REFERENCED;
4406 else {
4407 new.flags |= nflag;
4408 new.queue = nqueue;
4409 }
4410 } while (!vm_page_pqstate_commit(m, &old, new));
4411 }
4412
4413 /*
4414 * Unwire a page and either attempt to free it or re-add it to the page queues.
4415 */
4416 void
vm_page_release(vm_page_t m,int flags)4417 vm_page_release(vm_page_t m, int flags)
4418 {
4419 vm_object_t object;
4420
4421 KASSERT((m->oflags & VPO_UNMANAGED) == 0,
4422 ("vm_page_release: page %p is unmanaged", m));
4423
4424 if ((flags & VPR_TRYFREE) != 0) {
4425 for (;;) {
4426 object = atomic_load_ptr(&m->object);
4427 if (object == NULL)
4428 break;
4429 /* Depends on type-stability. */
4430 if (vm_page_busied(m) || !VM_OBJECT_TRYWLOCK(object))
4431 break;
4432 if (object == m->object) {
4433 vm_page_release_locked(m, flags);
4434 VM_OBJECT_WUNLOCK(object);
4435 return;
4436 }
4437 VM_OBJECT_WUNLOCK(object);
4438 }
4439 }
4440 vm_page_unwire_managed(m, PQ_INACTIVE, flags != 0);
4441 }
4442
4443 /* See vm_page_release(). */
4444 void
vm_page_release_locked(vm_page_t m,int flags)4445 vm_page_release_locked(vm_page_t m, int flags)
4446 {
4447
4448 VM_OBJECT_ASSERT_WLOCKED(m->object);
4449 KASSERT((m->oflags & VPO_UNMANAGED) == 0,
4450 ("vm_page_release_locked: page %p is unmanaged", m));
4451
4452 if (vm_page_unwire_noq(m)) {
4453 if ((flags & VPR_TRYFREE) != 0 &&
4454 (m->object->ref_count == 0 || !pmap_page_is_mapped(m)) &&
4455 m->dirty == 0 && vm_page_tryxbusy(m)) {
4456 /*
4457 * An unlocked lookup may have wired the page before the
4458 * busy lock was acquired, in which case the page must
4459 * not be freed.
4460 */
4461 if (__predict_true(!vm_page_wired(m))) {
4462 vm_page_free(m);
4463 return;
4464 }
4465 vm_page_xunbusy(m);
4466 } else {
4467 vm_page_release_toq(m, PQ_INACTIVE, flags != 0);
4468 }
4469 }
4470 }
4471
4472 static bool
vm_page_try_blocked_op(vm_page_t m,void (* op)(vm_page_t))4473 vm_page_try_blocked_op(vm_page_t m, void (*op)(vm_page_t))
4474 {
4475 u_int old;
4476
4477 KASSERT(m->object != NULL && (m->oflags & VPO_UNMANAGED) == 0,
4478 ("vm_page_try_blocked_op: page %p has no object", m));
4479 KASSERT(vm_page_busied(m),
4480 ("vm_page_try_blocked_op: page %p is not busy", m));
4481 VM_OBJECT_ASSERT_LOCKED(m->object);
4482
4483 old = m->ref_count;
4484 do {
4485 KASSERT(old != 0,
4486 ("vm_page_try_blocked_op: page %p has no references", m));
4487 if (VPRC_WIRE_COUNT(old) != 0)
4488 return (false);
4489 } while (!atomic_fcmpset_int(&m->ref_count, &old, old | VPRC_BLOCKED));
4490
4491 (op)(m);
4492
4493 /*
4494 * If the object is read-locked, new wirings may be created via an
4495 * object lookup.
4496 */
4497 old = vm_page_drop(m, VPRC_BLOCKED);
4498 KASSERT(!VM_OBJECT_WOWNED(m->object) ||
4499 old == (VPRC_BLOCKED | VPRC_OBJREF),
4500 ("vm_page_try_blocked_op: unexpected refcount value %u for %p",
4501 old, m));
4502 return (true);
4503 }
4504
4505 /*
4506 * Atomically check for wirings and remove all mappings of the page.
4507 */
4508 bool
vm_page_try_remove_all(vm_page_t m)4509 vm_page_try_remove_all(vm_page_t m)
4510 {
4511
4512 return (vm_page_try_blocked_op(m, pmap_remove_all));
4513 }
4514
4515 /*
4516 * Atomically check for wirings and remove all writeable mappings of the page.
4517 */
4518 bool
vm_page_try_remove_write(vm_page_t m)4519 vm_page_try_remove_write(vm_page_t m)
4520 {
4521
4522 return (vm_page_try_blocked_op(m, pmap_remove_write));
4523 }
4524
4525 /*
4526 * vm_page_advise
4527 *
4528 * Apply the specified advice to the given page.
4529 */
4530 void
vm_page_advise(vm_page_t m,int advice)4531 vm_page_advise(vm_page_t m, int advice)
4532 {
4533
4534 VM_OBJECT_ASSERT_WLOCKED(m->object);
4535 vm_page_assert_xbusied(m);
4536
4537 if (advice == MADV_FREE)
4538 /*
4539 * Mark the page clean. This will allow the page to be freed
4540 * without first paging it out. MADV_FREE pages are often
4541 * quickly reused by malloc(3), so we do not do anything that
4542 * would result in a page fault on a later access.
4543 */
4544 vm_page_undirty(m);
4545 else if (advice != MADV_DONTNEED) {
4546 if (advice == MADV_WILLNEED)
4547 vm_page_activate(m);
4548 return;
4549 }
4550
4551 if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m))
4552 vm_page_dirty(m);
4553
4554 /*
4555 * Clear any references to the page. Otherwise, the page daemon will
4556 * immediately reactivate the page.
4557 */
4558 vm_page_aflag_clear(m, PGA_REFERENCED);
4559
4560 /*
4561 * Place clean pages near the head of the inactive queue rather than
4562 * the tail, thus defeating the queue's LRU operation and ensuring that
4563 * the page will be reused quickly. Dirty pages not already in the
4564 * laundry are moved there.
4565 */
4566 if (m->dirty == 0)
4567 vm_page_deactivate_noreuse(m);
4568 else if (!vm_page_in_laundry(m))
4569 vm_page_launder(m);
4570 }
4571
4572 /*
4573 * vm_page_grab_release
4574 *
4575 * Helper routine for grab functions to release busy on return.
4576 */
4577 static inline void
vm_page_grab_release(vm_page_t m,int allocflags)4578 vm_page_grab_release(vm_page_t m, int allocflags)
4579 {
4580
4581 if ((allocflags & VM_ALLOC_NOBUSY) != 0) {
4582 if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0)
4583 vm_page_sunbusy(m);
4584 else
4585 vm_page_xunbusy(m);
4586 }
4587 }
4588
4589 /*
4590 * vm_page_grab_sleep
4591 *
4592 * Sleep for busy according to VM_ALLOC_ parameters. Returns true
4593 * if the caller should retry and false otherwise.
4594 *
4595 * If the object is locked on entry the object will be unlocked with
4596 * false returns and still locked but possibly having been dropped
4597 * with true returns.
4598 */
4599 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)4600 vm_page_grab_sleep(vm_object_t object, vm_page_t m, vm_pindex_t pindex,
4601 const char *wmesg, int allocflags, bool locked)
4602 {
4603
4604 if ((allocflags & VM_ALLOC_NOWAIT) != 0)
4605 return (false);
4606
4607 /*
4608 * Reference the page before unlocking and sleeping so that
4609 * the page daemon is less likely to reclaim it.
4610 */
4611 if (locked && (allocflags & VM_ALLOC_NOCREAT) == 0)
4612 vm_page_reference(m);
4613
4614 if (_vm_page_busy_sleep(object, m, pindex, wmesg, allocflags, locked) &&
4615 locked)
4616 VM_OBJECT_WLOCK(object);
4617 if ((allocflags & VM_ALLOC_WAITFAIL) != 0)
4618 return (false);
4619
4620 return (true);
4621 }
4622
4623 /*
4624 * Assert that the grab flags are valid.
4625 */
4626 static inline void
vm_page_grab_check(int allocflags)4627 vm_page_grab_check(int allocflags)
4628 {
4629
4630 KASSERT((allocflags & VM_ALLOC_NOBUSY) == 0 ||
4631 (allocflags & VM_ALLOC_WIRED) != 0,
4632 ("vm_page_grab*: the pages must be busied or wired"));
4633
4634 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 ||
4635 (allocflags & VM_ALLOC_IGN_SBUSY) != 0,
4636 ("vm_page_grab*: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch"));
4637 }
4638
4639 /*
4640 * Calculate the page allocation flags for grab.
4641 */
4642 static inline int
vm_page_grab_pflags(int allocflags)4643 vm_page_grab_pflags(int allocflags)
4644 {
4645 int pflags;
4646
4647 pflags = allocflags &
4648 ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL |
4649 VM_ALLOC_NOBUSY | VM_ALLOC_IGN_SBUSY);
4650 if ((allocflags & VM_ALLOC_NOWAIT) == 0)
4651 pflags |= VM_ALLOC_WAITFAIL;
4652 if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0)
4653 pflags |= VM_ALLOC_SBUSY;
4654
4655 return (pflags);
4656 }
4657
4658 /*
4659 * Grab a page, waiting until we are waken up due to the page
4660 * changing state. We keep on waiting, if the page continues
4661 * to be in the object. If the page doesn't exist, first allocate it
4662 * and then conditionally zero it.
4663 *
4664 * This routine may sleep.
4665 *
4666 * The object must be locked on entry. The lock will, however, be released
4667 * and reacquired if the routine sleeps.
4668 */
4669 vm_page_t
vm_page_grab(vm_object_t object,vm_pindex_t pindex,int allocflags)4670 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags)
4671 {
4672 vm_page_t m;
4673
4674 VM_OBJECT_ASSERT_WLOCKED(object);
4675 vm_page_grab_check(allocflags);
4676
4677 retrylookup:
4678 if ((m = vm_page_lookup(object, pindex)) != NULL) {
4679 if (!vm_page_tryacquire(m, allocflags)) {
4680 if (vm_page_grab_sleep(object, m, pindex, "pgrbwt",
4681 allocflags, true))
4682 goto retrylookup;
4683 return (NULL);
4684 }
4685 goto out;
4686 }
4687 if ((allocflags & VM_ALLOC_NOCREAT) != 0)
4688 return (NULL);
4689 m = vm_page_alloc(object, pindex, vm_page_grab_pflags(allocflags));
4690 if (m == NULL) {
4691 if ((allocflags & (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL)) != 0)
4692 return (NULL);
4693 goto retrylookup;
4694 }
4695 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0)
4696 pmap_zero_page(m);
4697
4698 out:
4699 vm_page_grab_release(m, allocflags);
4700
4701 return (m);
4702 }
4703
4704 /*
4705 * Locklessly attempt to acquire a page given a (object, pindex) tuple
4706 * and an optional previous page to avoid the radix lookup. The resulting
4707 * page will be validated against the identity tuple and busied or wired
4708 * as requested. A NULL *mp return guarantees that the page was not in
4709 * radix at the time of the call but callers must perform higher level
4710 * synchronization or retry the operation under a lock if they require
4711 * an atomic answer. This is the only lock free validation routine,
4712 * other routines can depend on the resulting page state.
4713 *
4714 * The return value indicates whether the operation failed due to caller
4715 * flags. The return is tri-state with mp:
4716 *
4717 * (true, *mp != NULL) - The operation was successful.
4718 * (true, *mp == NULL) - The page was not found in tree.
4719 * (false, *mp == NULL) - WAITFAIL or NOWAIT prevented acquisition.
4720 */
4721 static bool
vm_page_acquire_unlocked(vm_object_t object,vm_pindex_t pindex,vm_page_t prev,vm_page_t * mp,int allocflags)4722 vm_page_acquire_unlocked(vm_object_t object, vm_pindex_t pindex,
4723 vm_page_t prev, vm_page_t *mp, int allocflags)
4724 {
4725 vm_page_t m;
4726
4727 vm_page_grab_check(allocflags);
4728 MPASS(prev == NULL || vm_page_busied(prev) || vm_page_wired(prev));
4729
4730 *mp = NULL;
4731 for (;;) {
4732 /*
4733 * We may see a false NULL here because the previous page
4734 * has been removed or just inserted and the list is loaded
4735 * without barriers. Switch to radix to verify.
4736 */
4737 if (prev == NULL || (m = TAILQ_NEXT(prev, listq)) == NULL ||
4738 QMD_IS_TRASHED(m) || m->pindex != pindex ||
4739 atomic_load_ptr(&m->object) != object) {
4740 prev = NULL;
4741 /*
4742 * This guarantees the result is instantaneously
4743 * correct.
4744 */
4745 m = vm_radix_lookup_unlocked(&object->rtree, pindex);
4746 }
4747 if (m == NULL)
4748 return (true);
4749 if (vm_page_trybusy(m, allocflags)) {
4750 if (m->object == object && m->pindex == pindex)
4751 break;
4752 /* relookup. */
4753 vm_page_busy_release(m);
4754 cpu_spinwait();
4755 continue;
4756 }
4757 if (!vm_page_grab_sleep(object, m, pindex, "pgnslp",
4758 allocflags, false))
4759 return (false);
4760 }
4761 if ((allocflags & VM_ALLOC_WIRED) != 0)
4762 vm_page_wire(m);
4763 vm_page_grab_release(m, allocflags);
4764 *mp = m;
4765 return (true);
4766 }
4767
4768 /*
4769 * Try to locklessly grab a page and fall back to the object lock if NOCREAT
4770 * is not set.
4771 */
4772 vm_page_t
vm_page_grab_unlocked(vm_object_t object,vm_pindex_t pindex,int allocflags)4773 vm_page_grab_unlocked(vm_object_t object, vm_pindex_t pindex, int allocflags)
4774 {
4775 vm_page_t m;
4776
4777 vm_page_grab_check(allocflags);
4778
4779 if (!vm_page_acquire_unlocked(object, pindex, NULL, &m, allocflags))
4780 return (NULL);
4781 if (m != NULL)
4782 return (m);
4783
4784 /*
4785 * The radix lockless lookup should never return a false negative
4786 * errors. If the user specifies NOCREAT they are guaranteed there
4787 * was no page present at the instant of the call. A NOCREAT caller
4788 * must handle create races gracefully.
4789 */
4790 if ((allocflags & VM_ALLOC_NOCREAT) != 0)
4791 return (NULL);
4792
4793 VM_OBJECT_WLOCK(object);
4794 m = vm_page_grab(object, pindex, allocflags);
4795 VM_OBJECT_WUNLOCK(object);
4796
4797 return (m);
4798 }
4799
4800 /*
4801 * Grab a page and make it valid, paging in if necessary. Pages missing from
4802 * their pager are zero filled and validated. If a VM_ALLOC_COUNT is supplied
4803 * and the page is not valid as many as VM_INITIAL_PAGEIN pages can be brought
4804 * in simultaneously. Additional pages will be left on a paging queue but
4805 * will neither be wired nor busy regardless of allocflags.
4806 */
4807 int
vm_page_grab_valid(vm_page_t * mp,vm_object_t object,vm_pindex_t pindex,int allocflags)4808 vm_page_grab_valid(vm_page_t *mp, vm_object_t object, vm_pindex_t pindex, int allocflags)
4809 {
4810 vm_page_t m;
4811 vm_page_t ma[VM_INITIAL_PAGEIN];
4812 int after, i, pflags, rv;
4813
4814 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 ||
4815 (allocflags & VM_ALLOC_IGN_SBUSY) != 0,
4816 ("vm_page_grab_valid: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch"));
4817 KASSERT((allocflags &
4818 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0,
4819 ("vm_page_grab_valid: Invalid flags 0x%X", allocflags));
4820 VM_OBJECT_ASSERT_WLOCKED(object);
4821 pflags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY |
4822 VM_ALLOC_WIRED | VM_ALLOC_IGN_SBUSY);
4823 pflags |= VM_ALLOC_WAITFAIL;
4824
4825 retrylookup:
4826 if ((m = vm_page_lookup(object, pindex)) != NULL) {
4827 /*
4828 * If the page is fully valid it can only become invalid
4829 * with the object lock held. If it is not valid it can
4830 * become valid with the busy lock held. Therefore, we
4831 * may unnecessarily lock the exclusive busy here if we
4832 * race with I/O completion not using the object lock.
4833 * However, we will not end up with an invalid page and a
4834 * shared lock.
4835 */
4836 if (!vm_page_trybusy(m,
4837 vm_page_all_valid(m) ? allocflags : 0)) {
4838 (void)vm_page_grab_sleep(object, m, pindex, "pgrbwt",
4839 allocflags, true);
4840 goto retrylookup;
4841 }
4842 if (vm_page_all_valid(m))
4843 goto out;
4844 if ((allocflags & VM_ALLOC_NOCREAT) != 0) {
4845 vm_page_busy_release(m);
4846 *mp = NULL;
4847 return (VM_PAGER_FAIL);
4848 }
4849 } else if ((allocflags & VM_ALLOC_NOCREAT) != 0) {
4850 *mp = NULL;
4851 return (VM_PAGER_FAIL);
4852 } else if ((m = vm_page_alloc(object, pindex, pflags)) == NULL) {
4853 if (!vm_pager_can_alloc_page(object, pindex)) {
4854 *mp = NULL;
4855 return (VM_PAGER_AGAIN);
4856 }
4857 goto retrylookup;
4858 }
4859
4860 vm_page_assert_xbusied(m);
4861 if (vm_pager_has_page(object, pindex, NULL, &after)) {
4862 after = MIN(after, VM_INITIAL_PAGEIN);
4863 after = MIN(after, allocflags >> VM_ALLOC_COUNT_SHIFT);
4864 after = MAX(after, 1);
4865 ma[0] = m;
4866 for (i = 1; i < after; i++) {
4867 if ((ma[i] = vm_page_next(ma[i - 1])) != NULL) {
4868 if (vm_page_any_valid(ma[i]) ||
4869 !vm_page_tryxbusy(ma[i]))
4870 break;
4871 } else {
4872 ma[i] = vm_page_alloc(object, m->pindex + i,
4873 VM_ALLOC_NORMAL);
4874 if (ma[i] == NULL)
4875 break;
4876 }
4877 }
4878 after = i;
4879 vm_object_pip_add(object, after);
4880 VM_OBJECT_WUNLOCK(object);
4881 rv = vm_pager_get_pages(object, ma, after, NULL, NULL);
4882 VM_OBJECT_WLOCK(object);
4883 vm_object_pip_wakeupn(object, after);
4884 /* Pager may have replaced a page. */
4885 m = ma[0];
4886 if (rv != VM_PAGER_OK) {
4887 for (i = 0; i < after; i++) {
4888 if (!vm_page_wired(ma[i]))
4889 vm_page_free(ma[i]);
4890 else
4891 vm_page_xunbusy(ma[i]);
4892 }
4893 *mp = NULL;
4894 return (rv);
4895 }
4896 for (i = 1; i < after; i++)
4897 vm_page_readahead_finish(ma[i]);
4898 MPASS(vm_page_all_valid(m));
4899 } else {
4900 vm_page_zero_invalid(m, TRUE);
4901 }
4902 out:
4903 if ((allocflags & VM_ALLOC_WIRED) != 0)
4904 vm_page_wire(m);
4905 if ((allocflags & VM_ALLOC_SBUSY) != 0 && vm_page_xbusied(m))
4906 vm_page_busy_downgrade(m);
4907 else if ((allocflags & VM_ALLOC_NOBUSY) != 0)
4908 vm_page_busy_release(m);
4909 *mp = m;
4910 return (VM_PAGER_OK);
4911 }
4912
4913 /*
4914 * Locklessly grab a valid page. If the page is not valid or not yet
4915 * allocated this will fall back to the object lock method.
4916 */
4917 int
vm_page_grab_valid_unlocked(vm_page_t * mp,vm_object_t object,vm_pindex_t pindex,int allocflags)4918 vm_page_grab_valid_unlocked(vm_page_t *mp, vm_object_t object,
4919 vm_pindex_t pindex, int allocflags)
4920 {
4921 vm_page_t m;
4922 int flags;
4923 int error;
4924
4925 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 ||
4926 (allocflags & VM_ALLOC_IGN_SBUSY) != 0,
4927 ("vm_page_grab_valid_unlocked: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY "
4928 "mismatch"));
4929 KASSERT((allocflags &
4930 (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0,
4931 ("vm_page_grab_valid_unlocked: Invalid flags 0x%X", allocflags));
4932
4933 /*
4934 * Attempt a lockless lookup and busy. We need at least an sbusy
4935 * before we can inspect the valid field and return a wired page.
4936 */
4937 flags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_WIRED);
4938 if (!vm_page_acquire_unlocked(object, pindex, NULL, mp, flags))
4939 return (VM_PAGER_FAIL);
4940 if ((m = *mp) != NULL) {
4941 if (vm_page_all_valid(m)) {
4942 if ((allocflags & VM_ALLOC_WIRED) != 0)
4943 vm_page_wire(m);
4944 vm_page_grab_release(m, allocflags);
4945 return (VM_PAGER_OK);
4946 }
4947 vm_page_busy_release(m);
4948 }
4949 if ((allocflags & VM_ALLOC_NOCREAT) != 0) {
4950 *mp = NULL;
4951 return (VM_PAGER_FAIL);
4952 }
4953 VM_OBJECT_WLOCK(object);
4954 error = vm_page_grab_valid(mp, object, pindex, allocflags);
4955 VM_OBJECT_WUNLOCK(object);
4956
4957 return (error);
4958 }
4959
4960 /*
4961 * Return the specified range of pages from the given object. For each
4962 * page offset within the range, if a page already exists within the object
4963 * at that offset and it is busy, then wait for it to change state. If,
4964 * instead, the page doesn't exist, then allocate it.
4965 *
4966 * The caller must always specify an allocation class.
4967 *
4968 * allocation classes:
4969 * VM_ALLOC_NORMAL normal process request
4970 * VM_ALLOC_SYSTEM system *really* needs the pages
4971 *
4972 * The caller must always specify that the pages are to be busied and/or
4973 * wired.
4974 *
4975 * optional allocation flags:
4976 * VM_ALLOC_IGN_SBUSY do not sleep on soft busy pages
4977 * VM_ALLOC_NOBUSY do not exclusive busy the page
4978 * VM_ALLOC_NOWAIT do not sleep
4979 * VM_ALLOC_SBUSY set page to sbusy state
4980 * VM_ALLOC_WIRED wire the pages
4981 * VM_ALLOC_ZERO zero and validate any invalid pages
4982 *
4983 * If VM_ALLOC_NOWAIT is not specified, this routine may sleep. Otherwise, it
4984 * may return a partial prefix of the requested range.
4985 */
4986 int
vm_page_grab_pages(vm_object_t object,vm_pindex_t pindex,int allocflags,vm_page_t * ma,int count)4987 vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags,
4988 vm_page_t *ma, int count)
4989 {
4990 vm_page_t m, mpred;
4991 int pflags;
4992 int i;
4993
4994 VM_OBJECT_ASSERT_WLOCKED(object);
4995 KASSERT(((u_int)allocflags >> VM_ALLOC_COUNT_SHIFT) == 0,
4996 ("vm_page_grap_pages: VM_ALLOC_COUNT() is not allowed"));
4997 KASSERT(count > 0,
4998 ("vm_page_grab_pages: invalid page count %d", count));
4999 vm_page_grab_check(allocflags);
5000
5001 pflags = vm_page_grab_pflags(allocflags);
5002 i = 0;
5003 retrylookup:
5004 m = vm_radix_lookup_le(&object->rtree, pindex + i);
5005 if (m == NULL || m->pindex != pindex + i) {
5006 mpred = m;
5007 m = NULL;
5008 } else
5009 mpred = TAILQ_PREV(m, pglist, listq);
5010 for (; i < count; i++) {
5011 if (m != NULL) {
5012 if (!vm_page_tryacquire(m, allocflags)) {
5013 if (vm_page_grab_sleep(object, m, pindex + i,
5014 "grbmaw", allocflags, true))
5015 goto retrylookup;
5016 break;
5017 }
5018 } else {
5019 if ((allocflags & VM_ALLOC_NOCREAT) != 0)
5020 break;
5021 m = vm_page_alloc_after(object, pindex + i,
5022 pflags | VM_ALLOC_COUNT(count - i), mpred);
5023 if (m == NULL) {
5024 if ((allocflags & (VM_ALLOC_NOWAIT |
5025 VM_ALLOC_WAITFAIL)) != 0)
5026 break;
5027 goto retrylookup;
5028 }
5029 }
5030 if (vm_page_none_valid(m) &&
5031 (allocflags & VM_ALLOC_ZERO) != 0) {
5032 if ((m->flags & PG_ZERO) == 0)
5033 pmap_zero_page(m);
5034 vm_page_valid(m);
5035 }
5036 vm_page_grab_release(m, allocflags);
5037 ma[i] = mpred = m;
5038 m = vm_page_next(m);
5039 }
5040 return (i);
5041 }
5042
5043 /*
5044 * Unlocked variant of vm_page_grab_pages(). This accepts the same flags
5045 * and will fall back to the locked variant to handle allocation.
5046 */
5047 int
vm_page_grab_pages_unlocked(vm_object_t object,vm_pindex_t pindex,int allocflags,vm_page_t * ma,int count)5048 vm_page_grab_pages_unlocked(vm_object_t object, vm_pindex_t pindex,
5049 int allocflags, vm_page_t *ma, int count)
5050 {
5051 vm_page_t m, pred;
5052 int flags;
5053 int i;
5054
5055 KASSERT(count > 0,
5056 ("vm_page_grab_pages_unlocked: invalid page count %d", count));
5057 vm_page_grab_check(allocflags);
5058
5059 /*
5060 * Modify flags for lockless acquire to hold the page until we
5061 * set it valid if necessary.
5062 */
5063 flags = allocflags & ~VM_ALLOC_NOBUSY;
5064 pred = NULL;
5065 for (i = 0; i < count; i++, pindex++) {
5066 if (!vm_page_acquire_unlocked(object, pindex, pred, &m, flags))
5067 return (i);
5068 if (m == NULL)
5069 break;
5070 if ((flags & VM_ALLOC_ZERO) != 0 && vm_page_none_valid(m)) {
5071 if ((m->flags & PG_ZERO) == 0)
5072 pmap_zero_page(m);
5073 vm_page_valid(m);
5074 }
5075 /* m will still be wired or busy according to flags. */
5076 vm_page_grab_release(m, allocflags);
5077 pred = ma[i] = m;
5078 }
5079 if (i == count || (allocflags & VM_ALLOC_NOCREAT) != 0)
5080 return (i);
5081 count -= i;
5082 VM_OBJECT_WLOCK(object);
5083 i += vm_page_grab_pages(object, pindex, allocflags, &ma[i], count);
5084 VM_OBJECT_WUNLOCK(object);
5085
5086 return (i);
5087 }
5088
5089 /*
5090 * Mapping function for valid or dirty bits in a page.
5091 *
5092 * Inputs are required to range within a page.
5093 */
5094 vm_page_bits_t
vm_page_bits(int base,int size)5095 vm_page_bits(int base, int size)
5096 {
5097 int first_bit;
5098 int last_bit;
5099
5100 KASSERT(
5101 base + size <= PAGE_SIZE,
5102 ("vm_page_bits: illegal base/size %d/%d", base, size)
5103 );
5104
5105 if (size == 0) /* handle degenerate case */
5106 return (0);
5107
5108 first_bit = base >> DEV_BSHIFT;
5109 last_bit = (base + size - 1) >> DEV_BSHIFT;
5110
5111 return (((vm_page_bits_t)2 << last_bit) -
5112 ((vm_page_bits_t)1 << first_bit));
5113 }
5114
5115 void
vm_page_bits_set(vm_page_t m,vm_page_bits_t * bits,vm_page_bits_t set)5116 vm_page_bits_set(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t set)
5117 {
5118
5119 #if PAGE_SIZE == 32768
5120 atomic_set_64((uint64_t *)bits, set);
5121 #elif PAGE_SIZE == 16384
5122 atomic_set_32((uint32_t *)bits, set);
5123 #elif (PAGE_SIZE == 8192) && defined(atomic_set_16)
5124 atomic_set_16((uint16_t *)bits, set);
5125 #elif (PAGE_SIZE == 4096) && defined(atomic_set_8)
5126 atomic_set_8((uint8_t *)bits, set);
5127 #else /* PAGE_SIZE <= 8192 */
5128 uintptr_t addr;
5129 int shift;
5130
5131 addr = (uintptr_t)bits;
5132 /*
5133 * Use a trick to perform a 32-bit atomic on the
5134 * containing aligned word, to not depend on the existence
5135 * of atomic_{set, clear}_{8, 16}.
5136 */
5137 shift = addr & (sizeof(uint32_t) - 1);
5138 #if BYTE_ORDER == BIG_ENDIAN
5139 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY;
5140 #else
5141 shift *= NBBY;
5142 #endif
5143 addr &= ~(sizeof(uint32_t) - 1);
5144 atomic_set_32((uint32_t *)addr, set << shift);
5145 #endif /* PAGE_SIZE */
5146 }
5147
5148 static inline void
vm_page_bits_clear(vm_page_t m,vm_page_bits_t * bits,vm_page_bits_t clear)5149 vm_page_bits_clear(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t clear)
5150 {
5151
5152 #if PAGE_SIZE == 32768
5153 atomic_clear_64((uint64_t *)bits, clear);
5154 #elif PAGE_SIZE == 16384
5155 atomic_clear_32((uint32_t *)bits, clear);
5156 #elif (PAGE_SIZE == 8192) && defined(atomic_clear_16)
5157 atomic_clear_16((uint16_t *)bits, clear);
5158 #elif (PAGE_SIZE == 4096) && defined(atomic_clear_8)
5159 atomic_clear_8((uint8_t *)bits, clear);
5160 #else /* PAGE_SIZE <= 8192 */
5161 uintptr_t addr;
5162 int shift;
5163
5164 addr = (uintptr_t)bits;
5165 /*
5166 * Use a trick to perform a 32-bit atomic on the
5167 * containing aligned word, to not depend on the existence
5168 * of atomic_{set, clear}_{8, 16}.
5169 */
5170 shift = addr & (sizeof(uint32_t) - 1);
5171 #if BYTE_ORDER == BIG_ENDIAN
5172 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY;
5173 #else
5174 shift *= NBBY;
5175 #endif
5176 addr &= ~(sizeof(uint32_t) - 1);
5177 atomic_clear_32((uint32_t *)addr, clear << shift);
5178 #endif /* PAGE_SIZE */
5179 }
5180
5181 static inline vm_page_bits_t
vm_page_bits_swap(vm_page_t m,vm_page_bits_t * bits,vm_page_bits_t newbits)5182 vm_page_bits_swap(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t newbits)
5183 {
5184 #if PAGE_SIZE == 32768
5185 uint64_t old;
5186
5187 old = *bits;
5188 while (atomic_fcmpset_64(bits, &old, newbits) == 0);
5189 return (old);
5190 #elif PAGE_SIZE == 16384
5191 uint32_t old;
5192
5193 old = *bits;
5194 while (atomic_fcmpset_32(bits, &old, newbits) == 0);
5195 return (old);
5196 #elif (PAGE_SIZE == 8192) && defined(atomic_fcmpset_16)
5197 uint16_t old;
5198
5199 old = *bits;
5200 while (atomic_fcmpset_16(bits, &old, newbits) == 0);
5201 return (old);
5202 #elif (PAGE_SIZE == 4096) && defined(atomic_fcmpset_8)
5203 uint8_t old;
5204
5205 old = *bits;
5206 while (atomic_fcmpset_8(bits, &old, newbits) == 0);
5207 return (old);
5208 #else /* PAGE_SIZE <= 4096*/
5209 uintptr_t addr;
5210 uint32_t old, new, mask;
5211 int shift;
5212
5213 addr = (uintptr_t)bits;
5214 /*
5215 * Use a trick to perform a 32-bit atomic on the
5216 * containing aligned word, to not depend on the existence
5217 * of atomic_{set, swap, clear}_{8, 16}.
5218 */
5219 shift = addr & (sizeof(uint32_t) - 1);
5220 #if BYTE_ORDER == BIG_ENDIAN
5221 shift = (sizeof(uint32_t) - sizeof(vm_page_bits_t) - shift) * NBBY;
5222 #else
5223 shift *= NBBY;
5224 #endif
5225 addr &= ~(sizeof(uint32_t) - 1);
5226 mask = VM_PAGE_BITS_ALL << shift;
5227
5228 old = *bits;
5229 do {
5230 new = old & ~mask;
5231 new |= newbits << shift;
5232 } while (atomic_fcmpset_32((uint32_t *)addr, &old, new) == 0);
5233 return (old >> shift);
5234 #endif /* PAGE_SIZE */
5235 }
5236
5237 /*
5238 * vm_page_set_valid_range:
5239 *
5240 * Sets portions of a page valid. The arguments are expected
5241 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive
5242 * of any partial chunks touched by the range. The invalid portion of
5243 * such chunks will be zeroed.
5244 *
5245 * (base + size) must be less then or equal to PAGE_SIZE.
5246 */
5247 void
vm_page_set_valid_range(vm_page_t m,int base,int size)5248 vm_page_set_valid_range(vm_page_t m, int base, int size)
5249 {
5250 int endoff, frag;
5251 vm_page_bits_t pagebits;
5252
5253 vm_page_assert_busied(m);
5254 if (size == 0) /* handle degenerate case */
5255 return;
5256
5257 /*
5258 * If the base is not DEV_BSIZE aligned and the valid
5259 * bit is clear, we have to zero out a portion of the
5260 * first block.
5261 */
5262 if ((frag = rounddown2(base, DEV_BSIZE)) != base &&
5263 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0)
5264 pmap_zero_page_area(m, frag, base - frag);
5265
5266 /*
5267 * If the ending offset is not DEV_BSIZE aligned and the
5268 * valid bit is clear, we have to zero out a portion of
5269 * the last block.
5270 */
5271 endoff = base + size;
5272 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff &&
5273 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0)
5274 pmap_zero_page_area(m, endoff,
5275 DEV_BSIZE - (endoff & (DEV_BSIZE - 1)));
5276
5277 /*
5278 * Assert that no previously invalid block that is now being validated
5279 * is already dirty.
5280 */
5281 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0,
5282 ("vm_page_set_valid_range: page %p is dirty", m));
5283
5284 /*
5285 * Set valid bits inclusive of any overlap.
5286 */
5287 pagebits = vm_page_bits(base, size);
5288 if (vm_page_xbusied(m))
5289 m->valid |= pagebits;
5290 else
5291 vm_page_bits_set(m, &m->valid, pagebits);
5292 }
5293
5294 /*
5295 * Set the page dirty bits and free the invalid swap space if
5296 * present. Returns the previous dirty bits.
5297 */
5298 vm_page_bits_t
vm_page_set_dirty(vm_page_t m)5299 vm_page_set_dirty(vm_page_t m)
5300 {
5301 vm_page_bits_t old;
5302
5303 VM_PAGE_OBJECT_BUSY_ASSERT(m);
5304
5305 if (vm_page_xbusied(m) && !pmap_page_is_write_mapped(m)) {
5306 old = m->dirty;
5307 m->dirty = VM_PAGE_BITS_ALL;
5308 } else
5309 old = vm_page_bits_swap(m, &m->dirty, VM_PAGE_BITS_ALL);
5310 if (old == 0 && (m->a.flags & PGA_SWAP_SPACE) != 0)
5311 vm_pager_page_unswapped(m);
5312
5313 return (old);
5314 }
5315
5316 /*
5317 * Clear the given bits from the specified page's dirty field.
5318 */
5319 static __inline void
vm_page_clear_dirty_mask(vm_page_t m,vm_page_bits_t pagebits)5320 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits)
5321 {
5322
5323 vm_page_assert_busied(m);
5324
5325 /*
5326 * If the page is xbusied and not write mapped we are the
5327 * only thread that can modify dirty bits. Otherwise, The pmap
5328 * layer can call vm_page_dirty() without holding a distinguished
5329 * lock. The combination of page busy and atomic operations
5330 * suffice to guarantee consistency of the page dirty field.
5331 */
5332 if (vm_page_xbusied(m) && !pmap_page_is_write_mapped(m))
5333 m->dirty &= ~pagebits;
5334 else
5335 vm_page_bits_clear(m, &m->dirty, pagebits);
5336 }
5337
5338 /*
5339 * vm_page_set_validclean:
5340 *
5341 * Sets portions of a page valid and clean. The arguments are expected
5342 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive
5343 * of any partial chunks touched by the range. The invalid portion of
5344 * such chunks will be zero'd.
5345 *
5346 * (base + size) must be less then or equal to PAGE_SIZE.
5347 */
5348 void
vm_page_set_validclean(vm_page_t m,int base,int size)5349 vm_page_set_validclean(vm_page_t m, int base, int size)
5350 {
5351 vm_page_bits_t oldvalid, pagebits;
5352 int endoff, frag;
5353
5354 vm_page_assert_busied(m);
5355 if (size == 0) /* handle degenerate case */
5356 return;
5357
5358 /*
5359 * If the base is not DEV_BSIZE aligned and the valid
5360 * bit is clear, we have to zero out a portion of the
5361 * first block.
5362 */
5363 if ((frag = rounddown2(base, DEV_BSIZE)) != base &&
5364 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0)
5365 pmap_zero_page_area(m, frag, base - frag);
5366
5367 /*
5368 * If the ending offset is not DEV_BSIZE aligned and the
5369 * valid bit is clear, we have to zero out a portion of
5370 * the last block.
5371 */
5372 endoff = base + size;
5373 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff &&
5374 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0)
5375 pmap_zero_page_area(m, endoff,
5376 DEV_BSIZE - (endoff & (DEV_BSIZE - 1)));
5377
5378 /*
5379 * Set valid, clear dirty bits. If validating the entire
5380 * page we can safely clear the pmap modify bit. We also
5381 * use this opportunity to clear the PGA_NOSYNC flag. If a process
5382 * takes a write fault on a MAP_NOSYNC memory area the flag will
5383 * be set again.
5384 *
5385 * We set valid bits inclusive of any overlap, but we can only
5386 * clear dirty bits for DEV_BSIZE chunks that are fully within
5387 * the range.
5388 */
5389 oldvalid = m->valid;
5390 pagebits = vm_page_bits(base, size);
5391 if (vm_page_xbusied(m))
5392 m->valid |= pagebits;
5393 else
5394 vm_page_bits_set(m, &m->valid, pagebits);
5395 #if 0 /* NOT YET */
5396 if ((frag = base & (DEV_BSIZE - 1)) != 0) {
5397 frag = DEV_BSIZE - frag;
5398 base += frag;
5399 size -= frag;
5400 if (size < 0)
5401 size = 0;
5402 }
5403 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1));
5404 #endif
5405 if (base == 0 && size == PAGE_SIZE) {
5406 /*
5407 * The page can only be modified within the pmap if it is
5408 * mapped, and it can only be mapped if it was previously
5409 * fully valid.
5410 */
5411 if (oldvalid == VM_PAGE_BITS_ALL)
5412 /*
5413 * Perform the pmap_clear_modify() first. Otherwise,
5414 * a concurrent pmap operation, such as
5415 * pmap_protect(), could clear a modification in the
5416 * pmap and set the dirty field on the page before
5417 * pmap_clear_modify() had begun and after the dirty
5418 * field was cleared here.
5419 */
5420 pmap_clear_modify(m);
5421 m->dirty = 0;
5422 vm_page_aflag_clear(m, PGA_NOSYNC);
5423 } else if (oldvalid != VM_PAGE_BITS_ALL && vm_page_xbusied(m))
5424 m->dirty &= ~pagebits;
5425 else
5426 vm_page_clear_dirty_mask(m, pagebits);
5427 }
5428
5429 void
vm_page_clear_dirty(vm_page_t m,int base,int size)5430 vm_page_clear_dirty(vm_page_t m, int base, int size)
5431 {
5432
5433 vm_page_clear_dirty_mask(m, vm_page_bits(base, size));
5434 }
5435
5436 /*
5437 * vm_page_set_invalid:
5438 *
5439 * Invalidates DEV_BSIZE'd chunks within a page. Both the
5440 * valid and dirty bits for the effected areas are cleared.
5441 */
5442 void
vm_page_set_invalid(vm_page_t m,int base,int size)5443 vm_page_set_invalid(vm_page_t m, int base, int size)
5444 {
5445 vm_page_bits_t bits;
5446 vm_object_t object;
5447
5448 /*
5449 * The object lock is required so that pages can't be mapped
5450 * read-only while we're in the process of invalidating them.
5451 */
5452 object = m->object;
5453 VM_OBJECT_ASSERT_WLOCKED(object);
5454 vm_page_assert_busied(m);
5455
5456 if (object->type == OBJT_VNODE && base == 0 && IDX_TO_OFF(m->pindex) +
5457 size >= object->un_pager.vnp.vnp_size)
5458 bits = VM_PAGE_BITS_ALL;
5459 else
5460 bits = vm_page_bits(base, size);
5461 if (object->ref_count != 0 && vm_page_all_valid(m) && bits != 0)
5462 pmap_remove_all(m);
5463 KASSERT((bits == 0 && vm_page_all_valid(m)) ||
5464 !pmap_page_is_mapped(m),
5465 ("vm_page_set_invalid: page %p is mapped", m));
5466 if (vm_page_xbusied(m)) {
5467 m->valid &= ~bits;
5468 m->dirty &= ~bits;
5469 } else {
5470 vm_page_bits_clear(m, &m->valid, bits);
5471 vm_page_bits_clear(m, &m->dirty, bits);
5472 }
5473 }
5474
5475 /*
5476 * vm_page_invalid:
5477 *
5478 * Invalidates the entire page. The page must be busy, unmapped, and
5479 * the enclosing object must be locked. The object locks protects
5480 * against concurrent read-only pmap enter which is done without
5481 * busy.
5482 */
5483 void
vm_page_invalid(vm_page_t m)5484 vm_page_invalid(vm_page_t m)
5485 {
5486
5487 vm_page_assert_busied(m);
5488 VM_OBJECT_ASSERT_WLOCKED(m->object);
5489 MPASS(!pmap_page_is_mapped(m));
5490
5491 if (vm_page_xbusied(m))
5492 m->valid = 0;
5493 else
5494 vm_page_bits_clear(m, &m->valid, VM_PAGE_BITS_ALL);
5495 }
5496
5497 /*
5498 * vm_page_zero_invalid()
5499 *
5500 * The kernel assumes that the invalid portions of a page contain
5501 * garbage, but such pages can be mapped into memory by user code.
5502 * When this occurs, we must zero out the non-valid portions of the
5503 * page so user code sees what it expects.
5504 *
5505 * Pages are most often semi-valid when the end of a file is mapped
5506 * into memory and the file's size is not page aligned.
5507 */
5508 void
vm_page_zero_invalid(vm_page_t m,boolean_t setvalid)5509 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid)
5510 {
5511 int b;
5512 int i;
5513
5514 /*
5515 * Scan the valid bits looking for invalid sections that
5516 * must be zeroed. Invalid sub-DEV_BSIZE'd areas ( where the
5517 * valid bit may be set ) have already been zeroed by
5518 * vm_page_set_validclean().
5519 */
5520 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) {
5521 if (i == (PAGE_SIZE / DEV_BSIZE) ||
5522 (m->valid & ((vm_page_bits_t)1 << i))) {
5523 if (i > b) {
5524 pmap_zero_page_area(m,
5525 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT);
5526 }
5527 b = i + 1;
5528 }
5529 }
5530
5531 /*
5532 * setvalid is TRUE when we can safely set the zero'd areas
5533 * as being valid. We can do this if there are no cache consistency
5534 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS.
5535 */
5536 if (setvalid)
5537 vm_page_valid(m);
5538 }
5539
5540 /*
5541 * vm_page_is_valid:
5542 *
5543 * Is (partial) page valid? Note that the case where size == 0
5544 * will return FALSE in the degenerate case where the page is
5545 * entirely invalid, and TRUE otherwise.
5546 *
5547 * Some callers envoke this routine without the busy lock held and
5548 * handle races via higher level locks. Typical callers should
5549 * hold a busy lock to prevent invalidation.
5550 */
5551 int
vm_page_is_valid(vm_page_t m,int base,int size)5552 vm_page_is_valid(vm_page_t m, int base, int size)
5553 {
5554 vm_page_bits_t bits;
5555
5556 bits = vm_page_bits(base, size);
5557 return (vm_page_any_valid(m) && (m->valid & bits) == bits);
5558 }
5559
5560 /*
5561 * Returns true if all of the specified predicates are true for the entire
5562 * (super)page and false otherwise.
5563 */
5564 bool
vm_page_ps_test(vm_page_t m,int flags,vm_page_t skip_m)5565 vm_page_ps_test(vm_page_t m, int flags, vm_page_t skip_m)
5566 {
5567 vm_object_t object;
5568 int i, npages;
5569
5570 object = m->object;
5571 if (skip_m != NULL && skip_m->object != object)
5572 return (false);
5573 VM_OBJECT_ASSERT_LOCKED(object);
5574 npages = atop(pagesizes[m->psind]);
5575
5576 /*
5577 * The physically contiguous pages that make up a superpage, i.e., a
5578 * page with a page size index ("psind") greater than zero, will
5579 * occupy adjacent entries in vm_page_array[].
5580 */
5581 for (i = 0; i < npages; i++) {
5582 /* Always test object consistency, including "skip_m". */
5583 if (m[i].object != object)
5584 return (false);
5585 if (&m[i] == skip_m)
5586 continue;
5587 if ((flags & PS_NONE_BUSY) != 0 && vm_page_busied(&m[i]))
5588 return (false);
5589 if ((flags & PS_ALL_DIRTY) != 0) {
5590 /*
5591 * Calling vm_page_test_dirty() or pmap_is_modified()
5592 * might stop this case from spuriously returning
5593 * "false". However, that would require a write lock
5594 * on the object containing "m[i]".
5595 */
5596 if (m[i].dirty != VM_PAGE_BITS_ALL)
5597 return (false);
5598 }
5599 if ((flags & PS_ALL_VALID) != 0 &&
5600 m[i].valid != VM_PAGE_BITS_ALL)
5601 return (false);
5602 }
5603 return (true);
5604 }
5605
5606 /*
5607 * Set the page's dirty bits if the page is modified.
5608 */
5609 void
vm_page_test_dirty(vm_page_t m)5610 vm_page_test_dirty(vm_page_t m)
5611 {
5612
5613 vm_page_assert_busied(m);
5614 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m))
5615 vm_page_dirty(m);
5616 }
5617
5618 void
vm_page_valid(vm_page_t m)5619 vm_page_valid(vm_page_t m)
5620 {
5621
5622 vm_page_assert_busied(m);
5623 if (vm_page_xbusied(m))
5624 m->valid = VM_PAGE_BITS_ALL;
5625 else
5626 vm_page_bits_set(m, &m->valid, VM_PAGE_BITS_ALL);
5627 }
5628
5629 void
vm_page_lock_KBI(vm_page_t m,const char * file,int line)5630 vm_page_lock_KBI(vm_page_t m, const char *file, int line)
5631 {
5632
5633 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line);
5634 }
5635
5636 void
vm_page_unlock_KBI(vm_page_t m,const char * file,int line)5637 vm_page_unlock_KBI(vm_page_t m, const char *file, int line)
5638 {
5639
5640 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line);
5641 }
5642
5643 int
vm_page_trylock_KBI(vm_page_t m,const char * file,int line)5644 vm_page_trylock_KBI(vm_page_t m, const char *file, int line)
5645 {
5646
5647 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line));
5648 }
5649
5650 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
5651 void
vm_page_assert_locked_KBI(vm_page_t m,const char * file,int line)5652 vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line)
5653 {
5654
5655 vm_page_lock_assert_KBI(m, MA_OWNED, file, line);
5656 }
5657
5658 void
vm_page_lock_assert_KBI(vm_page_t m,int a,const char * file,int line)5659 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line)
5660 {
5661
5662 mtx_assert_(vm_page_lockptr(m), a, file, line);
5663 }
5664 #endif
5665
5666 #ifdef INVARIANTS
5667 void
vm_page_object_busy_assert(vm_page_t m)5668 vm_page_object_busy_assert(vm_page_t m)
5669 {
5670
5671 /*
5672 * Certain of the page's fields may only be modified by the
5673 * holder of a page or object busy.
5674 */
5675 if (m->object != NULL && !vm_page_busied(m))
5676 VM_OBJECT_ASSERT_BUSY(m->object);
5677 }
5678
5679 void
vm_page_assert_pga_writeable(vm_page_t m,uint16_t bits)5680 vm_page_assert_pga_writeable(vm_page_t m, uint16_t bits)
5681 {
5682
5683 if ((bits & PGA_WRITEABLE) == 0)
5684 return;
5685
5686 /*
5687 * The PGA_WRITEABLE flag can only be set if the page is
5688 * managed, is exclusively busied or the object is locked.
5689 * Currently, this flag is only set by pmap_enter().
5690 */
5691 KASSERT((m->oflags & VPO_UNMANAGED) == 0,
5692 ("PGA_WRITEABLE on unmanaged page"));
5693 if (!vm_page_xbusied(m))
5694 VM_OBJECT_ASSERT_BUSY(m->object);
5695 }
5696 #endif
5697
5698 #include "opt_ddb.h"
5699 #ifdef DDB
5700 #include <sys/kernel.h>
5701
5702 #include <ddb/ddb.h>
5703
DB_SHOW_COMMAND_FLAGS(page,vm_page_print_page_info,DB_CMD_MEMSAFE)5704 DB_SHOW_COMMAND_FLAGS(page, vm_page_print_page_info, DB_CMD_MEMSAFE)
5705 {
5706
5707 db_printf("vm_cnt.v_free_count: %d\n", vm_free_count());
5708 db_printf("vm_cnt.v_inactive_count: %d\n", vm_inactive_count());
5709 db_printf("vm_cnt.v_active_count: %d\n", vm_active_count());
5710 db_printf("vm_cnt.v_laundry_count: %d\n", vm_laundry_count());
5711 db_printf("vm_cnt.v_wire_count: %d\n", vm_wire_count());
5712 db_printf("vm_cnt.v_free_reserved: %d\n", vm_cnt.v_free_reserved);
5713 db_printf("vm_cnt.v_free_min: %d\n", vm_cnt.v_free_min);
5714 db_printf("vm_cnt.v_free_target: %d\n", vm_cnt.v_free_target);
5715 db_printf("vm_cnt.v_inactive_target: %d\n", vm_cnt.v_inactive_target);
5716 }
5717
DB_SHOW_COMMAND_FLAGS(pageq,vm_page_print_pageq_info,DB_CMD_MEMSAFE)5718 DB_SHOW_COMMAND_FLAGS(pageq, vm_page_print_pageq_info, DB_CMD_MEMSAFE)
5719 {
5720 int dom;
5721
5722 db_printf("pq_free %d\n", vm_free_count());
5723 for (dom = 0; dom < vm_ndomains; dom++) {
5724 db_printf(
5725 "dom %d page_cnt %d free %d pq_act %d pq_inact %d pq_laund %d pq_unsw %d\n",
5726 dom,
5727 vm_dom[dom].vmd_page_count,
5728 vm_dom[dom].vmd_free_count,
5729 vm_dom[dom].vmd_pagequeues[PQ_ACTIVE].pq_cnt,
5730 vm_dom[dom].vmd_pagequeues[PQ_INACTIVE].pq_cnt,
5731 vm_dom[dom].vmd_pagequeues[PQ_LAUNDRY].pq_cnt,
5732 vm_dom[dom].vmd_pagequeues[PQ_UNSWAPPABLE].pq_cnt);
5733 }
5734 }
5735
DB_SHOW_COMMAND(pginfo,vm_page_print_pginfo)5736 DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo)
5737 {
5738 vm_page_t m;
5739 boolean_t phys, virt;
5740
5741 if (!have_addr) {
5742 db_printf("show pginfo addr\n");
5743 return;
5744 }
5745
5746 phys = strchr(modif, 'p') != NULL;
5747 virt = strchr(modif, 'v') != NULL;
5748 if (virt)
5749 m = PHYS_TO_VM_PAGE(pmap_kextract(addr));
5750 else if (phys)
5751 m = PHYS_TO_VM_PAGE(addr);
5752 else
5753 m = (vm_page_t)addr;
5754 db_printf(
5755 "page %p obj %p pidx 0x%jx phys 0x%jx q %d ref 0x%x\n"
5756 " af 0x%x of 0x%x f 0x%x act %d busy %x valid 0x%x dirty 0x%x\n",
5757 m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr,
5758 m->a.queue, m->ref_count, m->a.flags, m->oflags,
5759 m->flags, m->a.act_count, m->busy_lock, m->valid, m->dirty);
5760 }
5761 #endif /* DDB */
5762