1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c)2006,2007,2008,2009 YAMAMOTO Takashi,
5 * Copyright (c) 2013 EMC Corp.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 /*
31 * From:
32 * $NetBSD: vmem_impl.h,v 1.2 2013/01/29 21:26:24 para Exp $
33 * $NetBSD: subr_vmem.c,v 1.83 2013/03/06 11:20:10 yamt Exp $
34 */
35
36 /*
37 * reference:
38 * - Magazines and Vmem: Extending the Slab Allocator
39 * to Many CPUs and Arbitrary Resources
40 * http://www.usenix.org/event/usenix01/bonwick.html
41 */
42
43 #include <sys/cdefs.h>
44 #include "opt_ddb.h"
45
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/kernel.h>
49 #include <sys/queue.h>
50 #include <sys/callout.h>
51 #include <sys/hash.h>
52 #include <sys/lock.h>
53 #include <sys/malloc.h>
54 #include <sys/mutex.h>
55 #include <sys/smp.h>
56 #include <sys/condvar.h>
57 #include <sys/sysctl.h>
58 #include <sys/taskqueue.h>
59 #include <sys/vmem.h>
60 #include <sys/vmmeter.h>
61
62 #include "opt_vm.h"
63
64 #include <vm/uma.h>
65 #include <vm/vm.h>
66 #include <vm/pmap.h>
67 #include <vm/vm_map.h>
68 #include <vm/vm_object.h>
69 #include <vm/vm_kern.h>
70 #include <vm/vm_extern.h>
71 #include <vm/vm_param.h>
72 #include <vm/vm_page.h>
73 #include <vm/vm_pageout.h>
74 #include <vm/vm_phys.h>
75 #include <vm/vm_pagequeue.h>
76 #include <vm/uma_int.h>
77
78 #define VMEM_OPTORDER 5
79 #define VMEM_OPTVALUE (1 << VMEM_OPTORDER)
80 #define VMEM_MAXORDER \
81 (VMEM_OPTVALUE - 1 + sizeof(vmem_size_t) * NBBY - VMEM_OPTORDER)
82
83 #define VMEM_HASHSIZE_MIN 16
84 #define VMEM_HASHSIZE_MAX 131072
85
86 #define VMEM_QCACHE_IDX_MAX 16
87
88 #define VMEM_FITMASK (M_BESTFIT | M_FIRSTFIT | M_NEXTFIT)
89
90 #define VMEM_FLAGS (M_NOWAIT | M_WAITOK | M_USE_RESERVE | M_NOVM | \
91 M_BESTFIT | M_FIRSTFIT | M_NEXTFIT)
92
93 #define BT_FLAGS (M_NOWAIT | M_WAITOK | M_USE_RESERVE | M_NOVM)
94
95 #define QC_NAME_MAX 16
96
97 /*
98 * Data structures private to vmem.
99 */
100 MALLOC_DEFINE(M_VMEM, "vmem", "vmem internal structures");
101
102 typedef struct vmem_btag bt_t;
103
104 TAILQ_HEAD(vmem_seglist, vmem_btag);
105 LIST_HEAD(vmem_freelist, vmem_btag);
106 LIST_HEAD(vmem_hashlist, vmem_btag);
107
108 struct qcache {
109 uma_zone_t qc_cache;
110 vmem_t *qc_vmem;
111 vmem_size_t qc_size;
112 char qc_name[QC_NAME_MAX];
113 };
114 typedef struct qcache qcache_t;
115 #define QC_POOL_TO_QCACHE(pool) ((qcache_t *)(pool->pr_qcache))
116
117 #define VMEM_NAME_MAX 16
118
119 /* boundary tag */
120 struct vmem_btag {
121 TAILQ_ENTRY(vmem_btag) bt_seglist;
122 union {
123 LIST_ENTRY(vmem_btag) u_freelist; /* BT_TYPE_FREE */
124 LIST_ENTRY(vmem_btag) u_hashlist; /* BT_TYPE_BUSY */
125 } bt_u;
126 #define bt_hashlist bt_u.u_hashlist
127 #define bt_freelist bt_u.u_freelist
128 vmem_addr_t bt_start;
129 vmem_size_t bt_size;
130 int bt_type;
131 };
132
133 /* vmem arena */
134 struct vmem {
135 struct mtx_padalign vm_lock;
136 struct cv vm_cv;
137 char vm_name[VMEM_NAME_MAX+1];
138 LIST_ENTRY(vmem) vm_alllist;
139 struct vmem_hashlist vm_hash0[VMEM_HASHSIZE_MIN];
140 struct vmem_freelist vm_freelist[VMEM_MAXORDER];
141 struct vmem_seglist vm_seglist;
142 struct vmem_hashlist *vm_hashlist;
143 vmem_size_t vm_hashsize;
144
145 /* Constant after init */
146 vmem_size_t vm_qcache_max;
147 vmem_size_t vm_quantum_mask;
148 vmem_size_t vm_import_quantum;
149 int vm_quantum_shift;
150
151 /* Written on alloc/free */
152 LIST_HEAD(, vmem_btag) vm_freetags;
153 int vm_nfreetags;
154 int vm_nbusytag;
155 vmem_size_t vm_inuse;
156 vmem_size_t vm_size;
157 vmem_size_t vm_limit;
158 struct vmem_btag vm_cursor;
159
160 /* Used on import. */
161 vmem_import_t *vm_importfn;
162 vmem_release_t *vm_releasefn;
163 void *vm_arg;
164
165 /* Space exhaustion callback. */
166 vmem_reclaim_t *vm_reclaimfn;
167
168 /* quantum cache */
169 qcache_t vm_qcache[VMEM_QCACHE_IDX_MAX];
170 };
171
172 #define BT_TYPE_SPAN 1 /* Allocated from importfn */
173 #define BT_TYPE_SPAN_STATIC 2 /* vmem_add() or create. */
174 #define BT_TYPE_FREE 3 /* Available space. */
175 #define BT_TYPE_BUSY 4 /* Used space. */
176 #define BT_TYPE_CURSOR 5 /* Cursor for nextfit allocations. */
177 #define BT_ISSPAN_P(bt) ((bt)->bt_type <= BT_TYPE_SPAN_STATIC)
178
179 #define BT_END(bt) ((bt)->bt_start + (bt)->bt_size - 1)
180
181 #if defined(DIAGNOSTIC)
182 static int enable_vmem_check = 0;
183 SYSCTL_INT(_debug, OID_AUTO, vmem_check, CTLFLAG_RWTUN,
184 &enable_vmem_check, 0, "Enable vmem check");
185 static void vmem_check(vmem_t *);
186 #endif
187
188 static struct callout vmem_periodic_ch;
189 static int vmem_periodic_interval;
190 static struct task vmem_periodic_wk;
191
192 static struct mtx_padalign __exclusive_cache_line vmem_list_lock;
193 static LIST_HEAD(, vmem) vmem_list = LIST_HEAD_INITIALIZER(vmem_list);
194 static uma_zone_t vmem_zone;
195
196 /* ---- misc */
197 #define VMEM_CONDVAR_INIT(vm, wchan) cv_init(&vm->vm_cv, wchan)
198 #define VMEM_CONDVAR_DESTROY(vm) cv_destroy(&vm->vm_cv)
199 #define VMEM_CONDVAR_WAIT(vm) cv_wait(&vm->vm_cv, &vm->vm_lock)
200 #define VMEM_CONDVAR_BROADCAST(vm) cv_broadcast(&vm->vm_cv)
201
202 #define VMEM_LOCK(vm) mtx_lock(&vm->vm_lock)
203 #define VMEM_TRYLOCK(vm) mtx_trylock(&vm->vm_lock)
204 #define VMEM_UNLOCK(vm) mtx_unlock(&vm->vm_lock)
205 #define VMEM_LOCK_INIT(vm, name) mtx_init(&vm->vm_lock, (name), NULL, MTX_DEF)
206 #define VMEM_LOCK_DESTROY(vm) mtx_destroy(&vm->vm_lock)
207 #define VMEM_ASSERT_LOCKED(vm) mtx_assert(&vm->vm_lock, MA_OWNED);
208
209 #define VMEM_ALIGNUP(addr, align) (-(-(addr) & -(align)))
210
211 #define VMEM_CROSS_P(addr1, addr2, boundary) \
212 ((((addr1) ^ (addr2)) & -(boundary)) != 0)
213
214 #define ORDER2SIZE(order) ((order) < VMEM_OPTVALUE ? ((order) + 1) : \
215 (vmem_size_t)1 << ((order) - (VMEM_OPTVALUE - VMEM_OPTORDER - 1)))
216 #define SIZE2ORDER(size) ((size) <= VMEM_OPTVALUE ? ((size) - 1) : \
217 (flsl(size) + (VMEM_OPTVALUE - VMEM_OPTORDER - 2)))
218
219 /*
220 * Maximum number of boundary tags that may be required to satisfy an
221 * allocation. Two may be required to import. Another two may be
222 * required to clip edges.
223 */
224 #define BT_MAXALLOC 4
225
226 /*
227 * Max free limits the number of locally cached boundary tags. We
228 * just want to avoid hitting the zone allocator for every call.
229 */
230 #define BT_MAXFREE (BT_MAXALLOC * 8)
231
232 /* Allocator for boundary tags. */
233 static uma_zone_t vmem_bt_zone;
234
235 /* boot time arena storage. */
236 static struct vmem kernel_arena_storage;
237 static struct vmem buffer_arena_storage;
238 static struct vmem transient_arena_storage;
239 vmem_t *kernel_arena = &kernel_arena_storage;
240 vmem_t *buffer_arena = &buffer_arena_storage;
241 vmem_t *transient_arena = &transient_arena_storage;
242
243 #ifdef DEBUG_MEMGUARD
244 static struct vmem memguard_arena_storage;
245 vmem_t *memguard_arena = &memguard_arena_storage;
246 #endif
247
248 static bool
bt_isbusy(bt_t * bt)249 bt_isbusy(bt_t *bt)
250 {
251 return (bt->bt_type == BT_TYPE_BUSY);
252 }
253
254 static bool
bt_isfree(bt_t * bt)255 bt_isfree(bt_t *bt)
256 {
257 return (bt->bt_type == BT_TYPE_FREE);
258 }
259
260 /*
261 * Fill the vmem's boundary tag cache. We guarantee that boundary tag
262 * allocation will not fail once bt_fill() passes. To do so we cache
263 * at least the maximum possible tag allocations in the arena.
264 */
265 static __noinline int
_bt_fill(vmem_t * vm,int flags)266 _bt_fill(vmem_t *vm, int flags)
267 {
268 bt_t *bt;
269
270 VMEM_ASSERT_LOCKED(vm);
271
272 /*
273 * Only allow the kernel arena and arenas derived from kernel arena to
274 * dip into reserve tags. They are where new tags come from.
275 */
276 flags &= BT_FLAGS;
277 if (vm != kernel_arena && vm->vm_arg != kernel_arena)
278 flags &= ~M_USE_RESERVE;
279
280 /*
281 * Loop until we meet the reserve. To minimize the lock shuffle
282 * and prevent simultaneous fills we first try a NOWAIT regardless
283 * of the caller's flags. Specify M_NOVM so we don't recurse while
284 * holding a vmem lock.
285 */
286 while (vm->vm_nfreetags < BT_MAXALLOC) {
287 bt = uma_zalloc(vmem_bt_zone,
288 (flags & M_USE_RESERVE) | M_NOWAIT | M_NOVM);
289 if (bt == NULL) {
290 VMEM_UNLOCK(vm);
291 bt = uma_zalloc(vmem_bt_zone, flags);
292 VMEM_LOCK(vm);
293 if (bt == NULL)
294 break;
295 }
296 LIST_INSERT_HEAD(&vm->vm_freetags, bt, bt_freelist);
297 vm->vm_nfreetags++;
298 }
299
300 if (vm->vm_nfreetags < BT_MAXALLOC)
301 return ENOMEM;
302
303 return 0;
304 }
305
306 static inline int
bt_fill(vmem_t * vm,int flags)307 bt_fill(vmem_t *vm, int flags)
308 {
309 if (vm->vm_nfreetags >= BT_MAXALLOC)
310 return (0);
311 return (_bt_fill(vm, flags));
312 }
313
314 /*
315 * Pop a tag off of the freetag stack.
316 */
317 static bt_t *
bt_alloc(vmem_t * vm)318 bt_alloc(vmem_t *vm)
319 {
320 bt_t *bt;
321
322 VMEM_ASSERT_LOCKED(vm);
323 bt = LIST_FIRST(&vm->vm_freetags);
324 MPASS(bt != NULL);
325 LIST_REMOVE(bt, bt_freelist);
326 vm->vm_nfreetags--;
327
328 return bt;
329 }
330
331 /*
332 * Trim the per-vmem free list. Returns with the lock released to
333 * avoid allocator recursions.
334 */
335 static void
bt_freetrim(vmem_t * vm,int freelimit)336 bt_freetrim(vmem_t *vm, int freelimit)
337 {
338 LIST_HEAD(, vmem_btag) freetags;
339 bt_t *bt;
340
341 LIST_INIT(&freetags);
342 VMEM_ASSERT_LOCKED(vm);
343 while (vm->vm_nfreetags > freelimit) {
344 bt = LIST_FIRST(&vm->vm_freetags);
345 LIST_REMOVE(bt, bt_freelist);
346 vm->vm_nfreetags--;
347 LIST_INSERT_HEAD(&freetags, bt, bt_freelist);
348 }
349 VMEM_UNLOCK(vm);
350 while ((bt = LIST_FIRST(&freetags)) != NULL) {
351 LIST_REMOVE(bt, bt_freelist);
352 uma_zfree(vmem_bt_zone, bt);
353 }
354 }
355
356 static inline void
bt_free(vmem_t * vm,bt_t * bt)357 bt_free(vmem_t *vm, bt_t *bt)
358 {
359
360 VMEM_ASSERT_LOCKED(vm);
361 MPASS(LIST_FIRST(&vm->vm_freetags) != bt);
362 LIST_INSERT_HEAD(&vm->vm_freetags, bt, bt_freelist);
363 vm->vm_nfreetags++;
364 }
365
366 /*
367 * Hide MAXALLOC tags before dropping the arena lock to ensure that a
368 * concurrent allocation attempt does not grab them.
369 */
370 static void
bt_save(vmem_t * vm)371 bt_save(vmem_t *vm)
372 {
373 KASSERT(vm->vm_nfreetags >= BT_MAXALLOC,
374 ("%s: insufficient free tags %d", __func__, vm->vm_nfreetags));
375 vm->vm_nfreetags -= BT_MAXALLOC;
376 }
377
378 static void
bt_restore(vmem_t * vm)379 bt_restore(vmem_t *vm)
380 {
381 vm->vm_nfreetags += BT_MAXALLOC;
382 }
383
384 /*
385 * freelist[0] ... [1, 1]
386 * freelist[1] ... [2, 2]
387 * :
388 * freelist[29] ... [30, 30]
389 * freelist[30] ... [31, 31]
390 * freelist[31] ... [32, 63]
391 * freelist[33] ... [64, 127]
392 * :
393 * freelist[n] ... [(1 << (n - 26)), (1 << (n - 25)) - 1]
394 * :
395 */
396
397 static struct vmem_freelist *
bt_freehead_tofree(vmem_t * vm,vmem_size_t size)398 bt_freehead_tofree(vmem_t *vm, vmem_size_t size)
399 {
400 const vmem_size_t qsize = size >> vm->vm_quantum_shift;
401 const int idx = SIZE2ORDER(qsize);
402
403 MPASS(size != 0 && qsize != 0);
404 MPASS((size & vm->vm_quantum_mask) == 0);
405 MPASS(idx >= 0);
406 MPASS(idx < VMEM_MAXORDER);
407
408 return &vm->vm_freelist[idx];
409 }
410
411 /*
412 * bt_freehead_toalloc: return the freelist for the given size and allocation
413 * strategy.
414 *
415 * For M_FIRSTFIT, return the list in which any blocks are large enough
416 * for the requested size. otherwise, return the list which can have blocks
417 * large enough for the requested size.
418 */
419 static struct vmem_freelist *
bt_freehead_toalloc(vmem_t * vm,vmem_size_t size,int strat)420 bt_freehead_toalloc(vmem_t *vm, vmem_size_t size, int strat)
421 {
422 const vmem_size_t qsize = size >> vm->vm_quantum_shift;
423 int idx = SIZE2ORDER(qsize);
424
425 MPASS(size != 0 && qsize != 0);
426 MPASS((size & vm->vm_quantum_mask) == 0);
427
428 if (strat == M_FIRSTFIT && ORDER2SIZE(idx) != qsize) {
429 idx++;
430 /* check too large request? */
431 }
432 MPASS(idx >= 0);
433 MPASS(idx < VMEM_MAXORDER);
434
435 return &vm->vm_freelist[idx];
436 }
437
438 /* ---- boundary tag hash */
439
440 static struct vmem_hashlist *
bt_hashhead(vmem_t * vm,vmem_addr_t addr)441 bt_hashhead(vmem_t *vm, vmem_addr_t addr)
442 {
443 struct vmem_hashlist *list;
444 unsigned int hash;
445
446 hash = hash32_buf(&addr, sizeof(addr), 0);
447 list = &vm->vm_hashlist[hash % vm->vm_hashsize];
448
449 return list;
450 }
451
452 static bt_t *
bt_lookupbusy(vmem_t * vm,vmem_addr_t addr)453 bt_lookupbusy(vmem_t *vm, vmem_addr_t addr)
454 {
455 struct vmem_hashlist *list;
456 bt_t *bt;
457
458 VMEM_ASSERT_LOCKED(vm);
459 list = bt_hashhead(vm, addr);
460 LIST_FOREACH(bt, list, bt_hashlist) {
461 if (bt->bt_start == addr) {
462 break;
463 }
464 }
465
466 return bt;
467 }
468
469 static void
bt_rembusy(vmem_t * vm,bt_t * bt)470 bt_rembusy(vmem_t *vm, bt_t *bt)
471 {
472
473 VMEM_ASSERT_LOCKED(vm);
474 MPASS(vm->vm_nbusytag > 0);
475 vm->vm_inuse -= bt->bt_size;
476 vm->vm_nbusytag--;
477 LIST_REMOVE(bt, bt_hashlist);
478 }
479
480 static void
bt_insbusy(vmem_t * vm,bt_t * bt)481 bt_insbusy(vmem_t *vm, bt_t *bt)
482 {
483 struct vmem_hashlist *list;
484
485 VMEM_ASSERT_LOCKED(vm);
486 MPASS(bt->bt_type == BT_TYPE_BUSY);
487
488 list = bt_hashhead(vm, bt->bt_start);
489 LIST_INSERT_HEAD(list, bt, bt_hashlist);
490 vm->vm_nbusytag++;
491 vm->vm_inuse += bt->bt_size;
492 }
493
494 /* ---- boundary tag list */
495
496 static void
bt_remseg(vmem_t * vm,bt_t * bt)497 bt_remseg(vmem_t *vm, bt_t *bt)
498 {
499
500 MPASS(bt->bt_type != BT_TYPE_CURSOR);
501 TAILQ_REMOVE(&vm->vm_seglist, bt, bt_seglist);
502 bt_free(vm, bt);
503 }
504
505 static void
bt_insseg(vmem_t * vm,bt_t * bt,bt_t * prev)506 bt_insseg(vmem_t *vm, bt_t *bt, bt_t *prev)
507 {
508
509 TAILQ_INSERT_AFTER(&vm->vm_seglist, prev, bt, bt_seglist);
510 }
511
512 static void
bt_insseg_tail(vmem_t * vm,bt_t * bt)513 bt_insseg_tail(vmem_t *vm, bt_t *bt)
514 {
515
516 TAILQ_INSERT_TAIL(&vm->vm_seglist, bt, bt_seglist);
517 }
518
519 static void
bt_remfree(vmem_t * vm __unused,bt_t * bt)520 bt_remfree(vmem_t *vm __unused, bt_t *bt)
521 {
522
523 MPASS(bt->bt_type == BT_TYPE_FREE);
524
525 LIST_REMOVE(bt, bt_freelist);
526 }
527
528 static void
bt_insfree(vmem_t * vm,bt_t * bt)529 bt_insfree(vmem_t *vm, bt_t *bt)
530 {
531 struct vmem_freelist *list;
532
533 list = bt_freehead_tofree(vm, bt->bt_size);
534 LIST_INSERT_HEAD(list, bt, bt_freelist);
535 }
536
537 /* ---- vmem internal functions */
538
539 /*
540 * Import from the arena into the quantum cache in UMA.
541 *
542 * We use VMEM_ADDR_QCACHE_MIN instead of 0: uma_zalloc() returns 0 to indicate
543 * failure, so UMA can't be used to cache a resource with value 0.
544 */
545 static int
qc_import(void * arg,void ** store,int cnt,int domain,int flags)546 qc_import(void *arg, void **store, int cnt, int domain, int flags)
547 {
548 qcache_t *qc;
549 vmem_addr_t addr;
550 int i;
551
552 KASSERT((flags & M_WAITOK) == 0, ("blocking allocation"));
553
554 qc = arg;
555 for (i = 0; i < cnt; i++) {
556 if (vmem_xalloc(qc->qc_vmem, qc->qc_size, 0, 0, 0,
557 VMEM_ADDR_QCACHE_MIN, VMEM_ADDR_MAX, flags, &addr) != 0)
558 break;
559 store[i] = (void *)addr;
560 }
561 return (i);
562 }
563
564 /*
565 * Release memory from the UMA cache to the arena.
566 */
567 static void
qc_release(void * arg,void ** store,int cnt)568 qc_release(void *arg, void **store, int cnt)
569 {
570 qcache_t *qc;
571 int i;
572
573 qc = arg;
574 for (i = 0; i < cnt; i++)
575 vmem_xfree(qc->qc_vmem, (vmem_addr_t)store[i], qc->qc_size);
576 }
577
578 static void
qc_init(vmem_t * vm,vmem_size_t qcache_max)579 qc_init(vmem_t *vm, vmem_size_t qcache_max)
580 {
581 qcache_t *qc;
582 vmem_size_t size;
583 int qcache_idx_max;
584 int i;
585
586 MPASS((qcache_max & vm->vm_quantum_mask) == 0);
587 qcache_idx_max = MIN(qcache_max >> vm->vm_quantum_shift,
588 VMEM_QCACHE_IDX_MAX);
589 vm->vm_qcache_max = qcache_idx_max << vm->vm_quantum_shift;
590 for (i = 0; i < qcache_idx_max; i++) {
591 qc = &vm->vm_qcache[i];
592 size = (i + 1) << vm->vm_quantum_shift;
593 snprintf(qc->qc_name, sizeof(qc->qc_name), "%s-%zu",
594 vm->vm_name, size);
595 qc->qc_vmem = vm;
596 qc->qc_size = size;
597 qc->qc_cache = uma_zcache_create(qc->qc_name, size,
598 NULL, NULL, NULL, NULL, qc_import, qc_release, qc, 0);
599 MPASS(qc->qc_cache);
600 }
601 }
602
603 static void
qc_destroy(vmem_t * vm)604 qc_destroy(vmem_t *vm)
605 {
606 int qcache_idx_max;
607 int i;
608
609 qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift;
610 for (i = 0; i < qcache_idx_max; i++)
611 uma_zdestroy(vm->vm_qcache[i].qc_cache);
612 }
613
614 static void
qc_drain(vmem_t * vm)615 qc_drain(vmem_t *vm)
616 {
617 int qcache_idx_max;
618 int i;
619
620 qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift;
621 for (i = 0; i < qcache_idx_max; i++)
622 uma_zone_reclaim(vm->vm_qcache[i].qc_cache, UMA_RECLAIM_DRAIN);
623 }
624
625 #ifndef UMA_USE_DMAP
626
627 static struct mtx_padalign __exclusive_cache_line vmem_bt_lock;
628
629 /*
630 * vmem_bt_alloc: Allocate a new page of boundary tags.
631 *
632 * On architectures with UMA_USE_DMAP there is no recursion; no address
633 * space need be allocated to allocate boundary tags. For the others, we
634 * must handle recursion. Boundary tags are necessary to allocate new
635 * boundary tags.
636 *
637 * UMA guarantees that enough tags are held in reserve to allocate a new
638 * page of kva. We dip into this reserve by specifying M_USE_RESERVE only
639 * when allocating the page to hold new boundary tags. In this way the
640 * reserve is automatically filled by the allocation that uses the reserve.
641 *
642 * We still have to guarantee that the new tags are allocated atomically since
643 * many threads may try concurrently. The bt_lock provides this guarantee.
644 * We convert WAITOK allocations to NOWAIT and then handle the blocking here
645 * on failure. It's ok to return NULL for a WAITOK allocation as UMA will
646 * loop again after checking to see if we lost the race to allocate.
647 *
648 * There is a small race between vmem_bt_alloc() returning the page and the
649 * zone lock being acquired to add the page to the zone. For WAITOK
650 * allocations we just pause briefly. NOWAIT may experience a transient
651 * failure. To alleviate this we permit a small number of simultaneous
652 * fills to proceed concurrently so NOWAIT is less likely to fail unless
653 * we are really out of KVA.
654 */
655 static void *
vmem_bt_alloc(uma_zone_t zone,vm_size_t bytes,int domain,uint8_t * pflag,int wait)656 vmem_bt_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
657 int wait)
658 {
659 vmem_addr_t addr;
660
661 *pflag = UMA_SLAB_KERNEL;
662
663 /*
664 * Single thread boundary tag allocation so that the address space
665 * and memory are added in one atomic operation.
666 */
667 mtx_lock(&vmem_bt_lock);
668 if (vmem_xalloc(vm_dom[domain].vmd_kernel_arena, bytes, 0, 0, 0,
669 VMEM_ADDR_MIN, VMEM_ADDR_MAX,
670 M_NOWAIT | M_NOVM | M_USE_RESERVE | M_BESTFIT, &addr) == 0) {
671 if (kmem_back_domain(domain, kernel_object, addr, bytes,
672 M_NOWAIT | M_USE_RESERVE) == 0) {
673 mtx_unlock(&vmem_bt_lock);
674 return ((void *)addr);
675 }
676 vmem_xfree(vm_dom[domain].vmd_kernel_arena, addr, bytes);
677 mtx_unlock(&vmem_bt_lock);
678 /*
679 * Out of memory, not address space. This may not even be
680 * possible due to M_USE_RESERVE page allocation.
681 */
682 if (wait & M_WAITOK)
683 vm_wait_domain(domain);
684 return (NULL);
685 }
686 mtx_unlock(&vmem_bt_lock);
687 /*
688 * We're either out of address space or lost a fill race.
689 */
690 if (wait & M_WAITOK)
691 pause("btalloc", 1);
692
693 return (NULL);
694 }
695 #endif
696
697 void
vmem_startup(void)698 vmem_startup(void)
699 {
700
701 mtx_init(&vmem_list_lock, "vmem list lock", NULL, MTX_DEF);
702 vmem_zone = uma_zcreate("vmem",
703 sizeof(struct vmem), NULL, NULL, NULL, NULL,
704 UMA_ALIGN_PTR, 0);
705 vmem_bt_zone = uma_zcreate("vmem btag",
706 sizeof(struct vmem_btag), NULL, NULL, NULL, NULL,
707 UMA_ALIGN_PTR, UMA_ZONE_VM);
708 #ifndef UMA_USE_DMAP
709 mtx_init(&vmem_bt_lock, "btag lock", NULL, MTX_DEF);
710 uma_prealloc(vmem_bt_zone, BT_MAXALLOC);
711 /*
712 * Reserve enough tags to allocate new tags. We allow multiple
713 * CPUs to attempt to allocate new tags concurrently to limit
714 * false restarts in UMA. vmem_bt_alloc() allocates from a per-domain
715 * arena, which may involve importing a range from the kernel arena,
716 * so we need to keep at least 2 * BT_MAXALLOC tags reserved.
717 */
718 uma_zone_reserve(vmem_bt_zone, 2 * BT_MAXALLOC * mp_ncpus);
719 uma_zone_set_allocf(vmem_bt_zone, vmem_bt_alloc);
720 #endif
721 }
722
723 /* ---- rehash */
724
725 static int
vmem_rehash(vmem_t * vm,vmem_size_t newhashsize)726 vmem_rehash(vmem_t *vm, vmem_size_t newhashsize)
727 {
728 bt_t *bt;
729 struct vmem_hashlist *newhashlist;
730 struct vmem_hashlist *oldhashlist;
731 vmem_size_t i, oldhashsize;
732
733 MPASS(newhashsize > 0);
734
735 newhashlist = malloc(sizeof(struct vmem_hashlist) * newhashsize,
736 M_VMEM, M_NOWAIT);
737 if (newhashlist == NULL)
738 return ENOMEM;
739 for (i = 0; i < newhashsize; i++) {
740 LIST_INIT(&newhashlist[i]);
741 }
742
743 VMEM_LOCK(vm);
744 oldhashlist = vm->vm_hashlist;
745 oldhashsize = vm->vm_hashsize;
746 vm->vm_hashlist = newhashlist;
747 vm->vm_hashsize = newhashsize;
748 if (oldhashlist == NULL) {
749 VMEM_UNLOCK(vm);
750 return 0;
751 }
752 for (i = 0; i < oldhashsize; i++) {
753 while ((bt = LIST_FIRST(&oldhashlist[i])) != NULL) {
754 bt_rembusy(vm, bt);
755 bt_insbusy(vm, bt);
756 }
757 }
758 VMEM_UNLOCK(vm);
759
760 if (oldhashlist != vm->vm_hash0)
761 free(oldhashlist, M_VMEM);
762
763 return 0;
764 }
765
766 static void
vmem_periodic_kick(void * dummy)767 vmem_periodic_kick(void *dummy)
768 {
769
770 taskqueue_enqueue(taskqueue_thread, &vmem_periodic_wk);
771 }
772
773 static void
vmem_periodic(void * unused,int pending)774 vmem_periodic(void *unused, int pending)
775 {
776 vmem_t *vm;
777 vmem_size_t desired;
778 vmem_size_t current;
779
780 mtx_lock(&vmem_list_lock);
781 LIST_FOREACH(vm, &vmem_list, vm_alllist) {
782 #ifdef DIAGNOSTIC
783 /* Convenient time to verify vmem state. */
784 if (enable_vmem_check == 1) {
785 VMEM_LOCK(vm);
786 vmem_check(vm);
787 VMEM_UNLOCK(vm);
788 }
789 #endif
790 desired = 1 << flsl(vm->vm_nbusytag);
791 desired = MIN(MAX(desired, VMEM_HASHSIZE_MIN),
792 VMEM_HASHSIZE_MAX);
793 current = vm->vm_hashsize;
794
795 /* Grow in powers of two. Shrink less aggressively. */
796 if (desired >= current * 2 || desired * 4 <= current)
797 vmem_rehash(vm, desired);
798
799 /*
800 * Periodically wake up threads waiting for resources,
801 * so they could ask for reclamation again.
802 */
803 VMEM_CONDVAR_BROADCAST(vm);
804 }
805 mtx_unlock(&vmem_list_lock);
806
807 callout_reset(&vmem_periodic_ch, vmem_periodic_interval,
808 vmem_periodic_kick, NULL);
809 }
810
811 static void
vmem_start_callout(void * unused)812 vmem_start_callout(void *unused)
813 {
814
815 TASK_INIT(&vmem_periodic_wk, 0, vmem_periodic, NULL);
816 vmem_periodic_interval = hz * 10;
817 callout_init(&vmem_periodic_ch, 1);
818 callout_reset(&vmem_periodic_ch, vmem_periodic_interval,
819 vmem_periodic_kick, NULL);
820 }
821 SYSINIT(vfs, SI_SUB_CONFIGURE, SI_ORDER_ANY, vmem_start_callout, NULL);
822
823 static void
vmem_add1(vmem_t * vm,vmem_addr_t addr,vmem_size_t size,int type)824 vmem_add1(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, int type)
825 {
826 bt_t *btfree, *btprev, *btspan;
827
828 VMEM_ASSERT_LOCKED(vm);
829 MPASS(type == BT_TYPE_SPAN || type == BT_TYPE_SPAN_STATIC);
830 MPASS((size & vm->vm_quantum_mask) == 0);
831
832 if (vm->vm_releasefn == NULL) {
833 /*
834 * The new segment will never be released, so see if it is
835 * contiguous with respect to an existing segment. In this case
836 * a span tag is not needed, and it may be possible now or in
837 * the future to coalesce the new segment with an existing free
838 * segment.
839 */
840 btprev = TAILQ_LAST(&vm->vm_seglist, vmem_seglist);
841 if ((!bt_isbusy(btprev) && !bt_isfree(btprev)) ||
842 btprev->bt_start + btprev->bt_size != addr)
843 btprev = NULL;
844 } else {
845 btprev = NULL;
846 }
847
848 if (btprev == NULL || bt_isbusy(btprev)) {
849 if (btprev == NULL) {
850 btspan = bt_alloc(vm);
851 btspan->bt_type = type;
852 btspan->bt_start = addr;
853 btspan->bt_size = size;
854 bt_insseg_tail(vm, btspan);
855 }
856
857 btfree = bt_alloc(vm);
858 btfree->bt_type = BT_TYPE_FREE;
859 btfree->bt_start = addr;
860 btfree->bt_size = size;
861 bt_insseg_tail(vm, btfree);
862 bt_insfree(vm, btfree);
863 } else {
864 bt_remfree(vm, btprev);
865 btprev->bt_size += size;
866 bt_insfree(vm, btprev);
867 }
868
869 vm->vm_size += size;
870 }
871
872 static void
vmem_destroy1(vmem_t * vm)873 vmem_destroy1(vmem_t *vm)
874 {
875 bt_t *bt;
876
877 /*
878 * Drain per-cpu quantum caches.
879 */
880 qc_destroy(vm);
881
882 /*
883 * The vmem should now only contain empty segments.
884 */
885 VMEM_LOCK(vm);
886 MPASS(vm->vm_nbusytag == 0);
887
888 TAILQ_REMOVE(&vm->vm_seglist, &vm->vm_cursor, bt_seglist);
889 while ((bt = TAILQ_FIRST(&vm->vm_seglist)) != NULL)
890 bt_remseg(vm, bt);
891
892 if (vm->vm_hashlist != NULL && vm->vm_hashlist != vm->vm_hash0)
893 free(vm->vm_hashlist, M_VMEM);
894
895 bt_freetrim(vm, 0);
896
897 VMEM_CONDVAR_DESTROY(vm);
898 VMEM_LOCK_DESTROY(vm);
899 uma_zfree(vmem_zone, vm);
900 }
901
902 static int
vmem_import(vmem_t * vm,vmem_size_t size,vmem_size_t align,int flags)903 vmem_import(vmem_t *vm, vmem_size_t size, vmem_size_t align, int flags)
904 {
905 vmem_addr_t addr;
906 int error;
907
908 if (vm->vm_importfn == NULL)
909 return (EINVAL);
910
911 /*
912 * To make sure we get a span that meets the alignment we double it
913 * and add the size to the tail. This slightly overestimates.
914 */
915 if (align != vm->vm_quantum_mask + 1)
916 size = (align * 2) + size;
917 size = roundup(size, vm->vm_import_quantum);
918
919 if (vm->vm_limit != 0 && vm->vm_limit < vm->vm_size + size)
920 return (ENOMEM);
921
922 bt_save(vm);
923 VMEM_UNLOCK(vm);
924 error = (vm->vm_importfn)(vm->vm_arg, size, flags, &addr);
925 VMEM_LOCK(vm);
926 bt_restore(vm);
927 if (error)
928 return (ENOMEM);
929
930 vmem_add1(vm, addr, size, BT_TYPE_SPAN);
931
932 return 0;
933 }
934
935 /*
936 * vmem_fit: check if a bt can satisfy the given restrictions.
937 *
938 * it's a caller's responsibility to ensure the region is big enough
939 * before calling us.
940 */
941 static int
vmem_fit(const bt_t * bt,vmem_size_t size,vmem_size_t align,vmem_size_t phase,vmem_size_t nocross,vmem_addr_t minaddr,vmem_addr_t maxaddr,vmem_addr_t * addrp)942 vmem_fit(const bt_t *bt, vmem_size_t size, vmem_size_t align,
943 vmem_size_t phase, vmem_size_t nocross, vmem_addr_t minaddr,
944 vmem_addr_t maxaddr, vmem_addr_t *addrp)
945 {
946 vmem_addr_t start;
947 vmem_addr_t end;
948
949 MPASS(size > 0);
950 MPASS(bt->bt_size >= size); /* caller's responsibility */
951
952 /*
953 * XXX assumption: vmem_addr_t and vmem_size_t are
954 * unsigned integer of the same size.
955 */
956
957 start = bt->bt_start;
958 if (start < minaddr) {
959 start = minaddr;
960 }
961 end = BT_END(bt);
962 if (end > maxaddr)
963 end = maxaddr;
964 if (start > end)
965 return (ENOMEM);
966
967 start = VMEM_ALIGNUP(start - phase, align) + phase;
968 if (start < bt->bt_start)
969 start += align;
970 if (VMEM_CROSS_P(start, start + size - 1, nocross)) {
971 MPASS(align < nocross);
972 start = VMEM_ALIGNUP(start - phase, nocross) + phase;
973 }
974 if (start <= end && end - start >= size - 1) {
975 MPASS((start & (align - 1)) == phase);
976 MPASS(!VMEM_CROSS_P(start, start + size - 1, nocross));
977 MPASS(minaddr <= start);
978 MPASS(maxaddr == 0 || start + size - 1 <= maxaddr);
979 MPASS(bt->bt_start <= start);
980 MPASS(BT_END(bt) - start >= size - 1);
981 *addrp = start;
982
983 return (0);
984 }
985 return (ENOMEM);
986 }
987
988 /*
989 * vmem_clip: Trim the boundary tag edges to the requested start and size.
990 */
991 static void
vmem_clip(vmem_t * vm,bt_t * bt,vmem_addr_t start,vmem_size_t size)992 vmem_clip(vmem_t *vm, bt_t *bt, vmem_addr_t start, vmem_size_t size)
993 {
994 bt_t *btnew;
995 bt_t *btprev;
996
997 VMEM_ASSERT_LOCKED(vm);
998 MPASS(bt->bt_type == BT_TYPE_FREE);
999 MPASS(bt->bt_size >= size);
1000 bt_remfree(vm, bt);
1001 if (bt->bt_start != start) {
1002 btprev = bt_alloc(vm);
1003 btprev->bt_type = BT_TYPE_FREE;
1004 btprev->bt_start = bt->bt_start;
1005 btprev->bt_size = start - bt->bt_start;
1006 bt->bt_start = start;
1007 bt->bt_size -= btprev->bt_size;
1008 bt_insfree(vm, btprev);
1009 bt_insseg(vm, btprev,
1010 TAILQ_PREV(bt, vmem_seglist, bt_seglist));
1011 }
1012 MPASS(bt->bt_start == start);
1013 if (bt->bt_size != size && bt->bt_size - size > vm->vm_quantum_mask) {
1014 /* split */
1015 btnew = bt_alloc(vm);
1016 btnew->bt_type = BT_TYPE_BUSY;
1017 btnew->bt_start = bt->bt_start;
1018 btnew->bt_size = size;
1019 bt->bt_start = bt->bt_start + size;
1020 bt->bt_size -= size;
1021 bt_insfree(vm, bt);
1022 bt_insseg(vm, btnew,
1023 TAILQ_PREV(bt, vmem_seglist, bt_seglist));
1024 bt_insbusy(vm, btnew);
1025 bt = btnew;
1026 } else {
1027 bt->bt_type = BT_TYPE_BUSY;
1028 bt_insbusy(vm, bt);
1029 }
1030 MPASS(bt->bt_size >= size);
1031 }
1032
1033 static int
vmem_try_fetch(vmem_t * vm,const vmem_size_t size,vmem_size_t align,int flags)1034 vmem_try_fetch(vmem_t *vm, const vmem_size_t size, vmem_size_t align, int flags)
1035 {
1036 vmem_size_t avail;
1037
1038 VMEM_ASSERT_LOCKED(vm);
1039
1040 /*
1041 * XXX it is possible to fail to meet xalloc constraints with the
1042 * imported region. It is up to the user to specify the
1043 * import quantum such that it can satisfy any allocation.
1044 */
1045 if (vmem_import(vm, size, align, flags) == 0)
1046 return (1);
1047
1048 /*
1049 * Try to free some space from the quantum cache or reclaim
1050 * functions if available.
1051 */
1052 if (vm->vm_qcache_max != 0 || vm->vm_reclaimfn != NULL) {
1053 avail = vm->vm_size - vm->vm_inuse;
1054 bt_save(vm);
1055 VMEM_UNLOCK(vm);
1056 if (vm->vm_qcache_max != 0)
1057 qc_drain(vm);
1058 if (vm->vm_reclaimfn != NULL)
1059 vm->vm_reclaimfn(vm, flags);
1060 VMEM_LOCK(vm);
1061 bt_restore(vm);
1062 /* If we were successful retry even NOWAIT. */
1063 if (vm->vm_size - vm->vm_inuse > avail)
1064 return (1);
1065 }
1066 if ((flags & M_NOWAIT) != 0)
1067 return (0);
1068 bt_save(vm);
1069 VMEM_CONDVAR_WAIT(vm);
1070 bt_restore(vm);
1071 return (1);
1072 }
1073
1074 static int
vmem_try_release(vmem_t * vm,struct vmem_btag * bt,const bool remfree)1075 vmem_try_release(vmem_t *vm, struct vmem_btag *bt, const bool remfree)
1076 {
1077 struct vmem_btag *prev;
1078
1079 MPASS(bt->bt_type == BT_TYPE_FREE);
1080
1081 if (vm->vm_releasefn == NULL)
1082 return (0);
1083
1084 prev = TAILQ_PREV(bt, vmem_seglist, bt_seglist);
1085 MPASS(prev != NULL);
1086 MPASS(prev->bt_type != BT_TYPE_FREE);
1087
1088 if (prev->bt_type == BT_TYPE_SPAN && prev->bt_size == bt->bt_size) {
1089 vmem_addr_t spanaddr;
1090 vmem_size_t spansize;
1091
1092 MPASS(prev->bt_start == bt->bt_start);
1093 spanaddr = prev->bt_start;
1094 spansize = prev->bt_size;
1095 if (remfree)
1096 bt_remfree(vm, bt);
1097 bt_remseg(vm, bt);
1098 bt_remseg(vm, prev);
1099 vm->vm_size -= spansize;
1100 VMEM_CONDVAR_BROADCAST(vm);
1101 bt_freetrim(vm, BT_MAXFREE);
1102 vm->vm_releasefn(vm->vm_arg, spanaddr, spansize);
1103 return (1);
1104 }
1105 return (0);
1106 }
1107
1108 static int
vmem_xalloc_nextfit(vmem_t * vm,const vmem_size_t size,vmem_size_t align,const vmem_size_t phase,const vmem_size_t nocross,int flags,vmem_addr_t * addrp)1109 vmem_xalloc_nextfit(vmem_t *vm, const vmem_size_t size, vmem_size_t align,
1110 const vmem_size_t phase, const vmem_size_t nocross, int flags,
1111 vmem_addr_t *addrp)
1112 {
1113 struct vmem_btag *bt, *cursor, *next, *prev;
1114 int error;
1115
1116 error = ENOMEM;
1117 VMEM_LOCK(vm);
1118
1119 /*
1120 * Make sure we have enough tags to complete the operation.
1121 */
1122 if (bt_fill(vm, flags) != 0)
1123 goto out;
1124
1125 retry:
1126 /*
1127 * Find the next free tag meeting our constraints. If one is found,
1128 * perform the allocation.
1129 */
1130 for (cursor = &vm->vm_cursor, bt = TAILQ_NEXT(cursor, bt_seglist);
1131 bt != cursor; bt = TAILQ_NEXT(bt, bt_seglist)) {
1132 if (bt == NULL)
1133 bt = TAILQ_FIRST(&vm->vm_seglist);
1134 if (bt->bt_type == BT_TYPE_FREE && bt->bt_size >= size &&
1135 (error = vmem_fit(bt, size, align, phase, nocross,
1136 VMEM_ADDR_MIN, VMEM_ADDR_MAX, addrp)) == 0) {
1137 vmem_clip(vm, bt, *addrp, size);
1138 break;
1139 }
1140 }
1141
1142 /*
1143 * Try to coalesce free segments around the cursor. If we succeed, and
1144 * have not yet satisfied the allocation request, try again with the
1145 * newly coalesced segment.
1146 */
1147 if ((next = TAILQ_NEXT(cursor, bt_seglist)) != NULL &&
1148 (prev = TAILQ_PREV(cursor, vmem_seglist, bt_seglist)) != NULL &&
1149 next->bt_type == BT_TYPE_FREE && prev->bt_type == BT_TYPE_FREE &&
1150 prev->bt_start + prev->bt_size == next->bt_start) {
1151 prev->bt_size += next->bt_size;
1152 bt_remfree(vm, next);
1153 bt_remseg(vm, next);
1154
1155 /*
1156 * The coalesced segment might be able to satisfy our request.
1157 * If not, we might need to release it from the arena.
1158 */
1159 if (error == ENOMEM && prev->bt_size >= size &&
1160 (error = vmem_fit(prev, size, align, phase, nocross,
1161 VMEM_ADDR_MIN, VMEM_ADDR_MAX, addrp)) == 0) {
1162 vmem_clip(vm, prev, *addrp, size);
1163 bt = prev;
1164 } else
1165 (void)vmem_try_release(vm, prev, true);
1166 }
1167
1168 /*
1169 * If the allocation was successful, advance the cursor.
1170 */
1171 if (error == 0) {
1172 TAILQ_REMOVE(&vm->vm_seglist, cursor, bt_seglist);
1173 for (; bt != NULL && bt->bt_start < *addrp + size;
1174 bt = TAILQ_NEXT(bt, bt_seglist))
1175 ;
1176 if (bt != NULL)
1177 TAILQ_INSERT_BEFORE(bt, cursor, bt_seglist);
1178 else
1179 TAILQ_INSERT_HEAD(&vm->vm_seglist, cursor, bt_seglist);
1180 }
1181
1182 /*
1183 * Attempt to bring additional resources into the arena. If that fails
1184 * and M_WAITOK is specified, sleep waiting for resources to be freed.
1185 */
1186 if (error == ENOMEM && vmem_try_fetch(vm, size, align, flags))
1187 goto retry;
1188
1189 out:
1190 VMEM_UNLOCK(vm);
1191 return (error);
1192 }
1193
1194 /* ---- vmem API */
1195
1196 void
vmem_set_import(vmem_t * vm,vmem_import_t * importfn,vmem_release_t * releasefn,void * arg,vmem_size_t import_quantum)1197 vmem_set_import(vmem_t *vm, vmem_import_t *importfn,
1198 vmem_release_t *releasefn, void *arg, vmem_size_t import_quantum)
1199 {
1200
1201 VMEM_LOCK(vm);
1202 KASSERT(vm->vm_size == 0, ("%s: arena is non-empty", __func__));
1203 vm->vm_importfn = importfn;
1204 vm->vm_releasefn = releasefn;
1205 vm->vm_arg = arg;
1206 vm->vm_import_quantum = import_quantum;
1207 VMEM_UNLOCK(vm);
1208 }
1209
1210 void
vmem_set_limit(vmem_t * vm,vmem_size_t limit)1211 vmem_set_limit(vmem_t *vm, vmem_size_t limit)
1212 {
1213
1214 VMEM_LOCK(vm);
1215 vm->vm_limit = limit;
1216 VMEM_UNLOCK(vm);
1217 }
1218
1219 void
vmem_set_reclaim(vmem_t * vm,vmem_reclaim_t * reclaimfn)1220 vmem_set_reclaim(vmem_t *vm, vmem_reclaim_t *reclaimfn)
1221 {
1222
1223 VMEM_LOCK(vm);
1224 vm->vm_reclaimfn = reclaimfn;
1225 VMEM_UNLOCK(vm);
1226 }
1227
1228 /*
1229 * vmem_init: Initializes vmem arena.
1230 */
1231 vmem_t *
vmem_init(vmem_t * vm,const char * name,vmem_addr_t base,vmem_size_t size,vmem_size_t quantum,vmem_size_t qcache_max,int flags)1232 vmem_init(vmem_t *vm, const char *name, vmem_addr_t base, vmem_size_t size,
1233 vmem_size_t quantum, vmem_size_t qcache_max, int flags)
1234 {
1235 vmem_size_t i;
1236
1237 MPASS(quantum > 0);
1238 MPASS((quantum & (quantum - 1)) == 0);
1239
1240 bzero(vm, sizeof(*vm));
1241
1242 VMEM_CONDVAR_INIT(vm, name);
1243 VMEM_LOCK_INIT(vm, name);
1244 vm->vm_nfreetags = 0;
1245 LIST_INIT(&vm->vm_freetags);
1246 strlcpy(vm->vm_name, name, sizeof(vm->vm_name));
1247 vm->vm_quantum_mask = quantum - 1;
1248 vm->vm_quantum_shift = flsl(quantum) - 1;
1249 vm->vm_nbusytag = 0;
1250 vm->vm_size = 0;
1251 vm->vm_limit = 0;
1252 vm->vm_inuse = 0;
1253 qc_init(vm, qcache_max);
1254
1255 TAILQ_INIT(&vm->vm_seglist);
1256 vm->vm_cursor.bt_start = vm->vm_cursor.bt_size = 0;
1257 vm->vm_cursor.bt_type = BT_TYPE_CURSOR;
1258 TAILQ_INSERT_TAIL(&vm->vm_seglist, &vm->vm_cursor, bt_seglist);
1259
1260 for (i = 0; i < VMEM_MAXORDER; i++)
1261 LIST_INIT(&vm->vm_freelist[i]);
1262
1263 memset(&vm->vm_hash0, 0, sizeof(vm->vm_hash0));
1264 vm->vm_hashsize = VMEM_HASHSIZE_MIN;
1265 vm->vm_hashlist = vm->vm_hash0;
1266
1267 if (size != 0) {
1268 if (vmem_add(vm, base, size, flags) != 0) {
1269 vmem_destroy1(vm);
1270 return NULL;
1271 }
1272 }
1273
1274 mtx_lock(&vmem_list_lock);
1275 LIST_INSERT_HEAD(&vmem_list, vm, vm_alllist);
1276 mtx_unlock(&vmem_list_lock);
1277
1278 return vm;
1279 }
1280
1281 /*
1282 * vmem_create: create an arena.
1283 */
1284 vmem_t *
vmem_create(const char * name,vmem_addr_t base,vmem_size_t size,vmem_size_t quantum,vmem_size_t qcache_max,int flags)1285 vmem_create(const char *name, vmem_addr_t base, vmem_size_t size,
1286 vmem_size_t quantum, vmem_size_t qcache_max, int flags)
1287 {
1288
1289 vmem_t *vm;
1290
1291 vm = uma_zalloc(vmem_zone, flags & (M_WAITOK|M_NOWAIT));
1292 if (vm == NULL)
1293 return (NULL);
1294 if (vmem_init(vm, name, base, size, quantum, qcache_max,
1295 flags) == NULL)
1296 return (NULL);
1297 return (vm);
1298 }
1299
1300 void
vmem_destroy(vmem_t * vm)1301 vmem_destroy(vmem_t *vm)
1302 {
1303
1304 mtx_lock(&vmem_list_lock);
1305 LIST_REMOVE(vm, vm_alllist);
1306 mtx_unlock(&vmem_list_lock);
1307
1308 vmem_destroy1(vm);
1309 }
1310
1311 vmem_size_t
vmem_roundup_size(vmem_t * vm,vmem_size_t size)1312 vmem_roundup_size(vmem_t *vm, vmem_size_t size)
1313 {
1314
1315 return (size + vm->vm_quantum_mask) & ~vm->vm_quantum_mask;
1316 }
1317
1318 /*
1319 * vmem_alloc: allocate resource from the arena.
1320 */
1321 int
vmem_alloc(vmem_t * vm,vmem_size_t size,int flags,vmem_addr_t * addrp)1322 vmem_alloc(vmem_t *vm, vmem_size_t size, int flags, vmem_addr_t *addrp)
1323 {
1324 const int strat __unused = flags & VMEM_FITMASK;
1325 qcache_t *qc;
1326
1327 flags &= VMEM_FLAGS;
1328 MPASS(size > 0);
1329 MPASS(strat == M_BESTFIT || strat == M_FIRSTFIT || strat == M_NEXTFIT);
1330 if ((flags & M_NOWAIT) == 0)
1331 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "vmem_alloc");
1332
1333 if (size <= vm->vm_qcache_max) {
1334 /*
1335 * Resource 0 cannot be cached, so avoid a blocking allocation
1336 * in qc_import() and give the vmem_xalloc() call below a chance
1337 * to return 0.
1338 */
1339 qc = &vm->vm_qcache[(size - 1) >> vm->vm_quantum_shift];
1340 *addrp = (vmem_addr_t)uma_zalloc(qc->qc_cache,
1341 (flags & ~M_WAITOK) | M_NOWAIT);
1342 if (__predict_true(*addrp != 0))
1343 return (0);
1344 }
1345
1346 return (vmem_xalloc(vm, size, 0, 0, 0, VMEM_ADDR_MIN, VMEM_ADDR_MAX,
1347 flags, addrp));
1348 }
1349
1350 int
vmem_xalloc(vmem_t * vm,const vmem_size_t size0,vmem_size_t align,const vmem_size_t phase,const vmem_size_t nocross,const vmem_addr_t minaddr,const vmem_addr_t maxaddr,int flags,vmem_addr_t * addrp)1351 vmem_xalloc(vmem_t *vm, const vmem_size_t size0, vmem_size_t align,
1352 const vmem_size_t phase, const vmem_size_t nocross,
1353 const vmem_addr_t minaddr, const vmem_addr_t maxaddr, int flags,
1354 vmem_addr_t *addrp)
1355 {
1356 const vmem_size_t size = vmem_roundup_size(vm, size0);
1357 struct vmem_freelist *list;
1358 struct vmem_freelist *first;
1359 struct vmem_freelist *end;
1360 bt_t *bt;
1361 int error;
1362 int strat;
1363
1364 flags &= VMEM_FLAGS;
1365 strat = flags & VMEM_FITMASK;
1366 MPASS(size0 > 0);
1367 MPASS(size > 0);
1368 MPASS(strat == M_BESTFIT || strat == M_FIRSTFIT || strat == M_NEXTFIT);
1369 MPASS((flags & (M_NOWAIT|M_WAITOK)) != (M_NOWAIT|M_WAITOK));
1370 if ((flags & M_NOWAIT) == 0)
1371 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "vmem_xalloc");
1372 MPASS((align & vm->vm_quantum_mask) == 0);
1373 MPASS((align & (align - 1)) == 0);
1374 MPASS((phase & vm->vm_quantum_mask) == 0);
1375 MPASS((nocross & vm->vm_quantum_mask) == 0);
1376 MPASS((nocross & (nocross - 1)) == 0);
1377 MPASS((align == 0 && phase == 0) || phase < align);
1378 MPASS(nocross == 0 || nocross >= size);
1379 MPASS(minaddr <= maxaddr);
1380 MPASS(!VMEM_CROSS_P(phase, phase + size - 1, nocross));
1381 if (strat == M_NEXTFIT)
1382 MPASS(minaddr == VMEM_ADDR_MIN && maxaddr == VMEM_ADDR_MAX);
1383
1384 if (align == 0)
1385 align = vm->vm_quantum_mask + 1;
1386 *addrp = 0;
1387
1388 /*
1389 * Next-fit allocations don't use the freelists.
1390 */
1391 if (strat == M_NEXTFIT)
1392 return (vmem_xalloc_nextfit(vm, size0, align, phase, nocross,
1393 flags, addrp));
1394
1395 end = &vm->vm_freelist[VMEM_MAXORDER];
1396 /*
1397 * choose a free block from which we allocate.
1398 */
1399 first = bt_freehead_toalloc(vm, size, strat);
1400 VMEM_LOCK(vm);
1401
1402 /*
1403 * Make sure we have enough tags to complete the operation.
1404 */
1405 error = bt_fill(vm, flags);
1406 if (error != 0)
1407 goto out;
1408 for (;;) {
1409 /*
1410 * Scan freelists looking for a tag that satisfies the
1411 * allocation. If we're doing BESTFIT we may encounter
1412 * sizes below the request. If we're doing FIRSTFIT we
1413 * inspect only the first element from each list.
1414 */
1415 for (list = first; list < end; list++) {
1416 LIST_FOREACH(bt, list, bt_freelist) {
1417 if (bt->bt_size >= size) {
1418 error = vmem_fit(bt, size, align, phase,
1419 nocross, minaddr, maxaddr, addrp);
1420 if (error == 0) {
1421 vmem_clip(vm, bt, *addrp, size);
1422 goto out;
1423 }
1424 }
1425 /* FIRST skips to the next list. */
1426 if (strat == M_FIRSTFIT)
1427 break;
1428 }
1429 }
1430
1431 /*
1432 * Retry if the fast algorithm failed.
1433 */
1434 if (strat == M_FIRSTFIT) {
1435 strat = M_BESTFIT;
1436 first = bt_freehead_toalloc(vm, size, strat);
1437 continue;
1438 }
1439
1440 /*
1441 * Try a few measures to bring additional resources into the
1442 * arena. If all else fails, we will sleep waiting for
1443 * resources to be freed.
1444 */
1445 if (!vmem_try_fetch(vm, size, align, flags)) {
1446 error = ENOMEM;
1447 break;
1448 }
1449 }
1450 out:
1451 VMEM_UNLOCK(vm);
1452 if (error != 0 && (flags & M_NOWAIT) == 0)
1453 panic("failed to allocate waiting allocation\n");
1454
1455 return (error);
1456 }
1457
1458 /*
1459 * vmem_free: free the resource to the arena.
1460 */
1461 void
vmem_free(vmem_t * vm,vmem_addr_t addr,vmem_size_t size)1462 vmem_free(vmem_t *vm, vmem_addr_t addr, vmem_size_t size)
1463 {
1464 qcache_t *qc;
1465 MPASS(size > 0);
1466
1467 if (size <= vm->vm_qcache_max &&
1468 __predict_true(addr >= VMEM_ADDR_QCACHE_MIN)) {
1469 qc = &vm->vm_qcache[(size - 1) >> vm->vm_quantum_shift];
1470 uma_zfree(qc->qc_cache, (void *)addr);
1471 } else
1472 vmem_xfree(vm, addr, size);
1473 }
1474
1475 void
vmem_xfree(vmem_t * vm,vmem_addr_t addr,vmem_size_t size __unused)1476 vmem_xfree(vmem_t *vm, vmem_addr_t addr, vmem_size_t size __unused)
1477 {
1478 bt_t *bt;
1479 bt_t *t;
1480
1481 MPASS(size > 0);
1482
1483 VMEM_LOCK(vm);
1484 bt = bt_lookupbusy(vm, addr);
1485 MPASS(bt != NULL);
1486 MPASS(bt->bt_start == addr);
1487 MPASS(bt->bt_size == vmem_roundup_size(vm, size) ||
1488 bt->bt_size - vmem_roundup_size(vm, size) <= vm->vm_quantum_mask);
1489 MPASS(bt->bt_type == BT_TYPE_BUSY);
1490 bt_rembusy(vm, bt);
1491 bt->bt_type = BT_TYPE_FREE;
1492
1493 /* coalesce */
1494 t = TAILQ_NEXT(bt, bt_seglist);
1495 if (t != NULL && t->bt_type == BT_TYPE_FREE) {
1496 MPASS(BT_END(bt) < t->bt_start); /* YYY */
1497 bt->bt_size += t->bt_size;
1498 bt_remfree(vm, t);
1499 bt_remseg(vm, t);
1500 }
1501 t = TAILQ_PREV(bt, vmem_seglist, bt_seglist);
1502 if (t != NULL && t->bt_type == BT_TYPE_FREE) {
1503 MPASS(BT_END(t) < bt->bt_start); /* YYY */
1504 bt->bt_size += t->bt_size;
1505 bt->bt_start = t->bt_start;
1506 bt_remfree(vm, t);
1507 bt_remseg(vm, t);
1508 }
1509
1510 if (!vmem_try_release(vm, bt, false)) {
1511 bt_insfree(vm, bt);
1512 VMEM_CONDVAR_BROADCAST(vm);
1513 bt_freetrim(vm, BT_MAXFREE);
1514 }
1515 }
1516
1517 /*
1518 * vmem_add:
1519 *
1520 */
1521 int
vmem_add(vmem_t * vm,vmem_addr_t addr,vmem_size_t size,int flags)1522 vmem_add(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, int flags)
1523 {
1524 int error;
1525
1526 flags &= VMEM_FLAGS;
1527
1528 VMEM_LOCK(vm);
1529 error = bt_fill(vm, flags);
1530 if (error == 0)
1531 vmem_add1(vm, addr, size, BT_TYPE_SPAN_STATIC);
1532 VMEM_UNLOCK(vm);
1533
1534 return (error);
1535 }
1536
1537 /*
1538 * vmem_size: information about arenas size
1539 */
1540 vmem_size_t
vmem_size(vmem_t * vm,int typemask)1541 vmem_size(vmem_t *vm, int typemask)
1542 {
1543 int i;
1544
1545 switch (typemask) {
1546 case VMEM_ALLOC:
1547 return vm->vm_inuse;
1548 case VMEM_FREE:
1549 return vm->vm_size - vm->vm_inuse;
1550 case VMEM_FREE|VMEM_ALLOC:
1551 return vm->vm_size;
1552 case VMEM_MAXFREE:
1553 VMEM_LOCK(vm);
1554 for (i = VMEM_MAXORDER - 1; i >= 0; i--) {
1555 if (LIST_EMPTY(&vm->vm_freelist[i]))
1556 continue;
1557 VMEM_UNLOCK(vm);
1558 return ((vmem_size_t)ORDER2SIZE(i) <<
1559 vm->vm_quantum_shift);
1560 }
1561 VMEM_UNLOCK(vm);
1562 return (0);
1563 default:
1564 panic("vmem_size");
1565 }
1566 }
1567
1568 /* ---- debug */
1569
1570 #if defined(DDB) || defined(DIAGNOSTIC)
1571
1572 static void bt_dump(const bt_t *, int (*)(const char *, ...)
1573 __printflike(1, 2));
1574
1575 static const char *
bt_type_string(int type)1576 bt_type_string(int type)
1577 {
1578
1579 switch (type) {
1580 case BT_TYPE_BUSY:
1581 return "busy";
1582 case BT_TYPE_FREE:
1583 return "free";
1584 case BT_TYPE_SPAN:
1585 return "span";
1586 case BT_TYPE_SPAN_STATIC:
1587 return "static span";
1588 case BT_TYPE_CURSOR:
1589 return "cursor";
1590 default:
1591 break;
1592 }
1593 return "BOGUS";
1594 }
1595
1596 static void
bt_dump(const bt_t * bt,int (* pr)(const char *,...))1597 bt_dump(const bt_t *bt, int (*pr)(const char *, ...))
1598 {
1599
1600 (*pr)("\t%p: %jx %jx, %d(%s)\n",
1601 bt, (intmax_t)bt->bt_start, (intmax_t)bt->bt_size,
1602 bt->bt_type, bt_type_string(bt->bt_type));
1603 }
1604
1605 static void
1606 vmem_dump(const vmem_t *vm , int (*pr)(const char *, ...) __printflike(1, 2))
1607 {
1608 const bt_t *bt;
1609 int i;
1610
1611 (*pr)("vmem %p '%s'\n", vm, vm->vm_name);
1612 TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1613 bt_dump(bt, pr);
1614 }
1615
1616 for (i = 0; i < VMEM_MAXORDER; i++) {
1617 const struct vmem_freelist *fl = &vm->vm_freelist[i];
1618
1619 if (LIST_EMPTY(fl)) {
1620 continue;
1621 }
1622
1623 (*pr)("freelist[%d]\n", i);
LIST_FOREACH(bt,fl,bt_freelist)1624 LIST_FOREACH(bt, fl, bt_freelist) {
1625 bt_dump(bt, pr);
1626 }
1627 }
1628 }
1629
1630 #endif /* defined(DDB) || defined(DIAGNOSTIC) */
1631
1632 #if defined(DDB)
1633 #include <ddb/ddb.h>
1634
1635 static bt_t *
vmem_whatis_lookup(vmem_t * vm,vmem_addr_t addr)1636 vmem_whatis_lookup(vmem_t *vm, vmem_addr_t addr)
1637 {
1638 bt_t *bt;
1639
1640 TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1641 if (BT_ISSPAN_P(bt)) {
1642 continue;
1643 }
1644 if (bt->bt_start <= addr && addr <= BT_END(bt)) {
1645 return bt;
1646 }
1647 }
1648
1649 return NULL;
1650 }
1651
1652 void
vmem_whatis(vmem_addr_t addr,int (* pr)(const char *,...))1653 vmem_whatis(vmem_addr_t addr, int (*pr)(const char *, ...))
1654 {
1655 vmem_t *vm;
1656
1657 LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1658 bt_t *bt;
1659
1660 bt = vmem_whatis_lookup(vm, addr);
1661 if (bt == NULL) {
1662 continue;
1663 }
1664 (*pr)("%p is %p+%zu in VMEM '%s' (%s)\n",
1665 (void *)addr, (void *)bt->bt_start,
1666 (vmem_size_t)(addr - bt->bt_start), vm->vm_name,
1667 (bt->bt_type == BT_TYPE_BUSY) ? "allocated" : "free");
1668 }
1669 }
1670
1671 void
vmem_printall(const char * modif,int (* pr)(const char *,...))1672 vmem_printall(const char *modif, int (*pr)(const char *, ...))
1673 {
1674 const vmem_t *vm;
1675
1676 LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1677 vmem_dump(vm, pr);
1678 }
1679 }
1680
1681 void
vmem_print(vmem_addr_t addr,const char * modif,int (* pr)(const char *,...))1682 vmem_print(vmem_addr_t addr, const char *modif, int (*pr)(const char *, ...))
1683 {
1684 const vmem_t *vm = (const void *)addr;
1685
1686 vmem_dump(vm, pr);
1687 }
1688
DB_SHOW_COMMAND(vmemdump,vmemdump)1689 DB_SHOW_COMMAND(vmemdump, vmemdump)
1690 {
1691
1692 if (!have_addr) {
1693 db_printf("usage: show vmemdump <addr>\n");
1694 return;
1695 }
1696
1697 vmem_dump((const vmem_t *)addr, db_printf);
1698 }
1699
DB_SHOW_ALL_COMMAND(vmemdump,vmemdumpall)1700 DB_SHOW_ALL_COMMAND(vmemdump, vmemdumpall)
1701 {
1702 const vmem_t *vm;
1703
1704 LIST_FOREACH(vm, &vmem_list, vm_alllist)
1705 vmem_dump(vm, db_printf);
1706 }
1707
DB_SHOW_COMMAND(vmem,vmem_summ)1708 DB_SHOW_COMMAND(vmem, vmem_summ)
1709 {
1710 const vmem_t *vm = (const void *)addr;
1711 const bt_t *bt;
1712 size_t ft[VMEM_MAXORDER], ut[VMEM_MAXORDER];
1713 size_t fs[VMEM_MAXORDER], us[VMEM_MAXORDER];
1714 int ord;
1715
1716 if (!have_addr) {
1717 db_printf("usage: show vmem <addr>\n");
1718 return;
1719 }
1720
1721 db_printf("vmem %p '%s'\n", vm, vm->vm_name);
1722 db_printf("\tquantum:\t%zu\n", vm->vm_quantum_mask + 1);
1723 db_printf("\tsize:\t%zu\n", vm->vm_size);
1724 db_printf("\tinuse:\t%zu\n", vm->vm_inuse);
1725 db_printf("\tfree:\t%zu\n", vm->vm_size - vm->vm_inuse);
1726 db_printf("\tbusy tags:\t%d\n", vm->vm_nbusytag);
1727 db_printf("\tfree tags:\t%d\n", vm->vm_nfreetags);
1728
1729 memset(&ft, 0, sizeof(ft));
1730 memset(&ut, 0, sizeof(ut));
1731 memset(&fs, 0, sizeof(fs));
1732 memset(&us, 0, sizeof(us));
1733 TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1734 ord = SIZE2ORDER(bt->bt_size >> vm->vm_quantum_shift);
1735 if (bt->bt_type == BT_TYPE_BUSY) {
1736 ut[ord]++;
1737 us[ord] += bt->bt_size;
1738 } else if (bt->bt_type == BT_TYPE_FREE) {
1739 ft[ord]++;
1740 fs[ord] += bt->bt_size;
1741 }
1742 }
1743 db_printf("\t\t\tinuse\tsize\t\tfree\tsize\n");
1744 for (ord = 0; ord < VMEM_MAXORDER; ord++) {
1745 if (ut[ord] == 0 && ft[ord] == 0)
1746 continue;
1747 db_printf("\t%-15zu %zu\t%-15zu %zu\t%-16zu\n",
1748 ORDER2SIZE(ord) << vm->vm_quantum_shift,
1749 ut[ord], us[ord], ft[ord], fs[ord]);
1750 }
1751 }
1752
DB_SHOW_ALL_COMMAND(vmem,vmem_summall)1753 DB_SHOW_ALL_COMMAND(vmem, vmem_summall)
1754 {
1755 const vmem_t *vm;
1756
1757 LIST_FOREACH(vm, &vmem_list, vm_alllist)
1758 vmem_summ((db_expr_t)vm, TRUE, count, modif);
1759 }
1760 #endif /* defined(DDB) */
1761
1762 #define vmem_printf printf
1763
1764 #if defined(DIAGNOSTIC)
1765
1766 static bool
vmem_check_sanity(vmem_t * vm)1767 vmem_check_sanity(vmem_t *vm)
1768 {
1769 const bt_t *bt, *bt2;
1770
1771 MPASS(vm != NULL);
1772
1773 TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1774 if (bt->bt_start > BT_END(bt)) {
1775 printf("corrupted tag\n");
1776 bt_dump(bt, vmem_printf);
1777 return false;
1778 }
1779 }
1780 TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1781 if (bt->bt_type == BT_TYPE_CURSOR) {
1782 if (bt->bt_start != 0 || bt->bt_size != 0) {
1783 printf("corrupted cursor\n");
1784 return false;
1785 }
1786 continue;
1787 }
1788 TAILQ_FOREACH(bt2, &vm->vm_seglist, bt_seglist) {
1789 if (bt == bt2) {
1790 continue;
1791 }
1792 if (bt2->bt_type == BT_TYPE_CURSOR) {
1793 continue;
1794 }
1795 if (BT_ISSPAN_P(bt) != BT_ISSPAN_P(bt2)) {
1796 continue;
1797 }
1798 if (bt->bt_start <= BT_END(bt2) &&
1799 bt2->bt_start <= BT_END(bt)) {
1800 printf("overwrapped tags\n");
1801 bt_dump(bt, vmem_printf);
1802 bt_dump(bt2, vmem_printf);
1803 return false;
1804 }
1805 }
1806 }
1807
1808 return true;
1809 }
1810
1811 static void
vmem_check(vmem_t * vm)1812 vmem_check(vmem_t *vm)
1813 {
1814
1815 if (!vmem_check_sanity(vm)) {
1816 panic("insanity vmem %p", vm);
1817 }
1818 }
1819
1820 #endif /* defined(DIAGNOSTIC) */
1821