1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
|
/*
* Copyright (c) 1991 Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* The Mach Operating System project at Carnegie-Mellon University.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)vm_page.c 7.4 (Berkeley) 5/7/91
*/
/*
* Copyright (c) 1987, 1990 Carnegie-Mellon University.
* All rights reserved.
*
* Authors: Avadis Tevanian, Jr., Michael Wayne Young
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/kernel.h>
#include <sys/linker_set.h>
#include <sys/sysctl.h>
#include <sys/vmmeter.h>
#include <sys/vnode.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_kern.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pageout.h>
#include <vm/vm_pager.h>
#include <vm/vm_extern.h>
static int
vm_contig_launder_page(vm_page_t m)
{
vm_object_t object;
vm_page_t m_tmp;
struct vnode *vp;
if (vm_page_sleep_if_busy(m, TRUE, "vpctw0")) {
vm_page_lock_queues();
return (EBUSY);
}
if (!VM_OBJECT_TRYLOCK(m->object))
return (EAGAIN);
vm_page_test_dirty(m);
if (m->dirty == 0 && m->hold_count == 0)
pmap_remove_all(m);
if (m->dirty) {
object = m->object;
if (object->type == OBJT_VNODE) {
vm_page_unlock_queues();
vp = object->handle;
VM_OBJECT_UNLOCK(object);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, curthread);
VM_OBJECT_LOCK(object);
vm_object_page_clean(object, 0, 0, OBJPC_SYNC);
VM_OBJECT_UNLOCK(object);
VOP_UNLOCK(vp, 0, curthread);
vm_page_lock_queues();
return (0);
} else if (object->type == OBJT_SWAP ||
object->type == OBJT_DEFAULT) {
m_tmp = m;
vm_pageout_flush(&m_tmp, 1, VM_PAGER_PUT_SYNC);
VM_OBJECT_UNLOCK(object);
return (0);
}
} else if (m->hold_count == 0)
vm_page_cache(m);
VM_OBJECT_UNLOCK(m->object);
return (0);
}
static int
vm_contig_launder(int queue)
{
vm_page_t m, next;
int error;
for (m = TAILQ_FIRST(&vm_page_queues[queue].pl); m != NULL; m = next) {
next = TAILQ_NEXT(m, pageq);
KASSERT(m->queue == queue,
("vm_contig_launder: page %p's queue is not %d", m, queue));
error = vm_contig_launder_page(m);
if (error == 0)
return (TRUE);
if (error == EBUSY)
return (FALSE);
}
return (FALSE);
}
/*
* This interface is for merging with malloc() someday.
* Even if we never implement compaction so that contiguous allocation
* works after initialization time, malloc()'s data structures are good
* for statistics and for allocations of less than a page.
*/
static void *
contigmalloc1(
unsigned long size, /* should be size_t here and for malloc() */
struct malloc_type *type,
int flags,
vm_paddr_t low,
vm_paddr_t high,
unsigned long alignment,
unsigned long boundary,
vm_map_t map)
{
int i, start;
vm_paddr_t phys;
vm_object_t object;
vm_offset_t addr, tmp_addr;
int pass, pqtype;
int inactl, actl, inactmax, actmax;
vm_page_t pga = vm_page_array;
size = round_page(size);
if (size == 0)
panic("contigmalloc1: size must not be 0");
if ((alignment & (alignment - 1)) != 0)
panic("contigmalloc1: alignment must be a power of 2");
if ((boundary & (boundary - 1)) != 0)
panic("contigmalloc1: boundary must be a power of 2");
start = 0;
for (pass = 2; pass >= 0; pass--) {
vm_page_lock_queues();
again0:
mtx_lock_spin(&vm_page_queue_free_mtx);
again:
/*
* Find first page in array that is free, within range,
* aligned, and such that the boundary won't be crossed.
*/
for (i = start; i < cnt.v_page_count; i++) {
phys = VM_PAGE_TO_PHYS(&pga[i]);
pqtype = pga[i].queue - pga[i].pc;
if (((pqtype == PQ_FREE) || (pqtype == PQ_CACHE)) &&
(phys >= low) && (phys < high) &&
((phys & (alignment - 1)) == 0) &&
(((phys ^ (phys + size - 1)) & ~(boundary - 1)) == 0))
break;
}
/*
* If the above failed or we will exceed the upper bound, fail.
*/
if ((i == cnt.v_page_count) ||
((VM_PAGE_TO_PHYS(&pga[i]) + size) > high)) {
mtx_unlock_spin(&vm_page_queue_free_mtx);
/*
* Instead of racing to empty the inactive/active
* queues, give up, even with more left to free,
* if we try more than the initial amount of pages.
*
* There's no point attempting this on the last pass.
*/
if (pass > 0) {
inactl = actl = 0;
inactmax = vm_page_queues[PQ_INACTIVE].lcnt;
actmax = vm_page_queues[PQ_ACTIVE].lcnt;
again1:
if (inactl < inactmax &&
vm_contig_launder(PQ_INACTIVE)) {
inactl++;
goto again1;
}
if (actl < actmax &&
vm_contig_launder(PQ_ACTIVE)) {
actl++;
goto again1;
}
}
vm_page_unlock_queues();
continue;
}
start = i;
/*
* Check successive pages for contiguous and free.
*/
for (i = start + 1; i < (start + size / PAGE_SIZE); i++) {
pqtype = pga[i].queue - pga[i].pc;
if ((VM_PAGE_TO_PHYS(&pga[i]) !=
(VM_PAGE_TO_PHYS(&pga[i - 1]) + PAGE_SIZE)) ||
((pqtype != PQ_FREE) && (pqtype != PQ_CACHE))) {
start++;
goto again;
}
}
mtx_unlock_spin(&vm_page_queue_free_mtx);
for (i = start; i < (start + size / PAGE_SIZE); i++) {
vm_page_t m = &pga[i];
if ((m->queue - m->pc) == PQ_CACHE) {
object = m->object;
if (!VM_OBJECT_TRYLOCK(object)) {
start++;
goto again0;
}
vm_page_busy(m);
vm_page_free(m);
VM_OBJECT_UNLOCK(object);
}
}
mtx_lock_spin(&vm_page_queue_free_mtx);
for (i = start; i < (start + size / PAGE_SIZE); i++) {
pqtype = pga[i].queue - pga[i].pc;
if (pqtype != PQ_FREE) {
start++;
goto again;
}
}
for (i = start; i < (start + size / PAGE_SIZE); i++) {
vm_page_t m = &pga[i];
vm_pageq_remove_nowakeup(m);
m->valid = VM_PAGE_BITS_ALL;
if (m->flags & PG_ZERO)
vm_page_zero_count--;
/* Don't clear the PG_ZERO flag, we'll need it later. */
m->flags = PG_UNMANAGED | (m->flags & PG_ZERO);
KASSERT(m->dirty == 0,
("contigmalloc1: page %p was dirty", m));
m->wire_count = 0;
m->busy = 0;
m->object = NULL;
}
mtx_unlock_spin(&vm_page_queue_free_mtx);
vm_page_unlock_queues();
/*
* We've found a contiguous chunk that meets are requirements.
* Allocate kernel VM, unfree and assign the physical pages to
* it and return kernel VM pointer.
*/
vm_map_lock(map);
if (vm_map_findspace(map, vm_map_min(map), size, &addr) !=
KERN_SUCCESS) {
/*
* XXX We almost never run out of kernel virtual
* space, so we don't make the allocated memory
* above available.
*/
vm_map_unlock(map);
return (NULL);
}
vm_object_reference(kernel_object);
vm_map_insert(map, kernel_object, addr - VM_MIN_KERNEL_ADDRESS,
addr, addr + size, VM_PROT_ALL, VM_PROT_ALL, 0);
vm_map_unlock(map);
tmp_addr = addr;
VM_OBJECT_LOCK(kernel_object);
for (i = start; i < (start + size / PAGE_SIZE); i++) {
vm_page_t m = &pga[i];
vm_page_insert(m, kernel_object,
OFF_TO_IDX(tmp_addr - VM_MIN_KERNEL_ADDRESS));
if ((flags & M_ZERO) && !(m->flags & PG_ZERO))
pmap_zero_page(m);
tmp_addr += PAGE_SIZE;
}
VM_OBJECT_UNLOCK(kernel_object);
vm_map_wire(map, addr, addr + size,
VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
return ((void *)addr);
}
return (NULL);
}
static void
vm_page_release_contigl(vm_page_t m, vm_pindex_t count)
{
mtx_lock_spin(&vm_page_queue_free_mtx);
while (count--) {
vm_page_free_toq(m);
m++;
}
mtx_unlock_spin(&vm_page_queue_free_mtx);
}
void
vm_page_release_contig(vm_page_t m, vm_pindex_t count)
{
vm_page_lock_queues();
vm_page_release_contigl(m, count);
vm_page_unlock_queues();
}
static int
vm_contig_unqueue_free(vm_page_t m)
{
int error = 0;
mtx_lock_spin(&vm_page_queue_free_mtx);
if ((m->queue - m->pc) == PQ_FREE)
vm_pageq_remove_nowakeup(m);
else
error = EAGAIN;
mtx_unlock_spin(&vm_page_queue_free_mtx);
if (error)
return (error);
m->valid = VM_PAGE_BITS_ALL;
if (m->flags & PG_ZERO)
vm_page_zero_count--;
/* Don't clear the PG_ZERO flag; we'll need it later. */
m->flags = PG_UNMANAGED | (m->flags & PG_ZERO);
KASSERT(m->dirty == 0,
("contigmalloc2: page %p was dirty", m));
m->wire_count = 0;
m->busy = 0;
m->object = NULL;
return (error);
}
vm_page_t
vm_page_alloc_contig(vm_pindex_t npages, vm_paddr_t low, vm_paddr_t high,
vm_offset_t alignment, vm_offset_t boundary)
{
vm_object_t object;
vm_offset_t size;
vm_paddr_t phys;
vm_page_t pga = vm_page_array;
int i, pass, pqtype, start;
size = npages << PAGE_SHIFT;
if (size == 0)
panic("vm_page_alloc_contig: size must not be 0");
if ((alignment & (alignment - 1)) != 0)
panic("vm_page_alloc_contig: alignment must be a power of 2");
if ((boundary & (boundary - 1)) != 0)
panic("vm_page_alloc_contig: boundary must be a power of 2");
for (pass = 0; pass < 2; pass++) {
start = vm_page_array_size;
vm_page_lock_queues();
retry:
start--;
/*
* Find last page in array that is free, within range,
* aligned, and such that the boundary won't be crossed.
*/
for (i = start; i >= 0; i--) {
phys = VM_PAGE_TO_PHYS(&pga[i]);
pqtype = pga[i].queue - pga[i].pc;
if (pass == 0) {
if (pqtype != PQ_FREE && pqtype != PQ_CACHE)
continue;
} else if (pqtype != PQ_FREE && pqtype != PQ_CACHE &&
pga[i].queue != PQ_ACTIVE &&
pga[i].queue != PQ_INACTIVE)
continue;
if (phys >= low && phys + size <= high &&
((phys & (alignment - 1)) == 0) &&
((phys ^ (phys + size - 1)) & ~(boundary - 1)) == 0)
break;
}
/* There are no candidates at all. */
if (i == -1) {
vm_page_unlock_queues();
continue;
}
start = i;
/*
* Check successive pages for contiguous and free.
*/
for (i = start + 1; i < start + npages; i++) {
pqtype = pga[i].queue - pga[i].pc;
if (VM_PAGE_TO_PHYS(&pga[i]) !=
VM_PAGE_TO_PHYS(&pga[i - 1]) + PAGE_SIZE)
goto retry;
if (pass == 0) {
if (pqtype != PQ_FREE && pqtype != PQ_CACHE)
goto retry;
} else if (pqtype != PQ_FREE && pqtype != PQ_CACHE &&
pga[i].queue != PQ_ACTIVE &&
pga[i].queue != PQ_INACTIVE)
goto retry;
}
for (i = start; i < start + npages; i++) {
vm_page_t m = &pga[i];
retry_page:
pqtype = m->queue - m->pc;
if (pass != 0 && pqtype != PQ_FREE &&
pqtype != PQ_CACHE) {
switch (m->queue) {
case PQ_ACTIVE:
case PQ_INACTIVE:
if (vm_contig_launder_page(m) != 0)
goto cleanup_freed;
pqtype = m->queue - m->pc;
if (pqtype == PQ_FREE ||
pqtype == PQ_CACHE)
break;
default:
cleanup_freed:
vm_page_release_contigl(&pga[start],
i - start);
goto retry;
}
}
if (pqtype == PQ_CACHE) {
object = m->object;
if (!VM_OBJECT_TRYLOCK(object))
goto retry;
vm_page_busy(m);
vm_page_free(m);
VM_OBJECT_UNLOCK(object);
}
/*
* There is no good API for freeing a page
* directly to PQ_NONE on our behalf, so spin.
*/
if (vm_contig_unqueue_free(m) != 0)
goto retry_page;
}
vm_page_unlock_queues();
/*
* We've found a contiguous chunk that meets are requirements.
*/
return (&pga[start]);
}
return (NULL);
}
static void *
contigmalloc2(vm_page_t m, vm_pindex_t npages, int flags)
{
vm_object_t object = kernel_object;
vm_map_t map = kernel_map;
vm_offset_t addr, tmp_addr;
vm_pindex_t i;
/*
* Allocate kernel VM, unfree and assign the physical pages to
* it and return kernel VM pointer.
*/
vm_map_lock(map);
if (vm_map_findspace(map, vm_map_min(map), npages << PAGE_SHIFT, &addr)
!= KERN_SUCCESS) {
vm_map_unlock(map);
return (NULL);
}
vm_object_reference(object);
vm_map_insert(map, object, addr - VM_MIN_KERNEL_ADDRESS,
addr, addr + (npages << PAGE_SHIFT), VM_PROT_ALL, VM_PROT_ALL, 0);
vm_map_unlock(map);
tmp_addr = addr;
VM_OBJECT_LOCK(object);
for (i = 0; i < npages; i++) {
vm_page_insert(&m[i], object,
OFF_TO_IDX(tmp_addr - VM_MIN_KERNEL_ADDRESS));
if ((flags & M_ZERO) && !(m->flags & PG_ZERO))
pmap_zero_page(&m[i]);
tmp_addr += PAGE_SIZE;
}
VM_OBJECT_UNLOCK(object);
vm_map_wire(map, addr, addr + (npages << PAGE_SHIFT),
VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES);
return ((void *)addr);
}
static int vm_old_contigmalloc = 1;
SYSCTL_INT(_vm, OID_AUTO, old_contigmalloc,
CTLFLAG_RW, &vm_old_contigmalloc, 0, "Use the old contigmalloc algorithm");
TUNABLE_INT("vm.old_contigmalloc", &vm_old_contigmalloc);
void *
contigmalloc(
unsigned long size, /* should be size_t here and for malloc() */
struct malloc_type *type,
int flags,
vm_paddr_t low,
vm_paddr_t high,
unsigned long alignment,
unsigned long boundary)
{
void * ret;
vm_page_t pages;
vm_pindex_t npgs;
npgs = round_page(size) >> PAGE_SHIFT;
mtx_lock(&Giant);
if (vm_old_contigmalloc) {
ret = contigmalloc1(size, type, flags, low, high, alignment,
boundary, kernel_map);
} else {
pages = vm_page_alloc_contig(npgs, low, high,
alignment, boundary);
if (pages == NULL) {
ret = NULL;
} else {
ret = contigmalloc2(pages, npgs, flags);
if (ret == NULL)
vm_page_release_contig(pages, npgs);
}
}
mtx_unlock(&Giant);
malloc_type_allocated(type, ret == NULL ? 0 : npgs << PAGE_SHIFT);
return (ret);
}
void
contigfree(void *addr, unsigned long size, struct malloc_type *type)
{
vm_pindex_t npgs;
npgs = round_page(size) >> PAGE_SHIFT;
kmem_free(kernel_map, (vm_offset_t)addr, size);
malloc_type_freed(type, npgs << PAGE_SHIFT);
}
|