xref: /netbsd-src/sys/kern/subr_vmem.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: subr_vmem.c,v 1.37 2007/12/13 02:45:10 yamt Exp $	*/
2 
3 /*-
4  * Copyright (c)2006 YAMAMOTO Takashi,
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 /*
30  * reference:
31  * -	Magazines and Vmem: Extending the Slab Allocator
32  *	to Many CPUs and Arbitrary Resources
33  *	http://www.usenix.org/event/usenix01/bonwick.html
34  *
35  * todo:
36  * -	decide how to import segments for vmem_xalloc.
37  * -	don't rely on malloc(9).
38  */
39 
40 #include <sys/cdefs.h>
41 __KERNEL_RCSID(0, "$NetBSD: subr_vmem.c,v 1.37 2007/12/13 02:45:10 yamt Exp $");
42 
43 #define	VMEM_DEBUG
44 #if defined(_KERNEL)
45 #include "opt_ddb.h"
46 #define	QCACHE
47 #endif /* defined(_KERNEL) */
48 
49 #include <sys/param.h>
50 #include <sys/hash.h>
51 #include <sys/queue.h>
52 
53 #if defined(_KERNEL)
54 #include <sys/systm.h>
55 #include <sys/kernel.h>	/* hz */
56 #include <sys/callout.h>
57 #include <sys/lock.h>
58 #include <sys/malloc.h>
59 #include <sys/once.h>
60 #include <sys/pool.h>
61 #include <sys/proc.h>
62 #include <sys/vmem.h>
63 #include <sys/workqueue.h>
64 #else /* defined(_KERNEL) */
65 #include "../sys/vmem.h"
66 #endif /* defined(_KERNEL) */
67 
68 #if defined(_KERNEL)
69 #define	LOCK_DECL(name)		kmutex_t name
70 #else /* defined(_KERNEL) */
71 #include <errno.h>
72 #include <assert.h>
73 #include <stdlib.h>
74 
75 #define	KASSERT(a)		assert(a)
76 #define	LOCK_DECL(name)		/* nothing */
77 #define	mutex_init(a, b, c)	/* nothing */
78 #define	mutex_destroy(a)	/* nothing */
79 #define	mutex_enter(a)		/* nothing */
80 #define	mutex_exit(a)		/* nothing */
81 #define	mutex_owned(a)		/* nothing */
82 #define	ASSERT_SLEEPABLE(lk, msg) /* nothing */
83 #define	IPL_VM			0
84 #endif /* defined(_KERNEL) */
85 
86 struct vmem;
87 struct vmem_btag;
88 
89 #if defined(VMEM_DEBUG)
90 void vmem_dump(const vmem_t *);
91 #endif /* defined(VMEM_DEBUG) */
92 
93 #define	VMEM_MAXORDER		(sizeof(vmem_size_t) * CHAR_BIT)
94 
95 #define	VMEM_HASHSIZE_MIN	1	/* XXX */
96 #define	VMEM_HASHSIZE_MAX	8192	/* XXX */
97 #define	VMEM_HASHSIZE_INIT	VMEM_HASHSIZE_MIN
98 
99 #define	VM_FITMASK	(VM_BESTFIT | VM_INSTANTFIT)
100 
101 CIRCLEQ_HEAD(vmem_seglist, vmem_btag);
102 LIST_HEAD(vmem_freelist, vmem_btag);
103 LIST_HEAD(vmem_hashlist, vmem_btag);
104 
105 #if defined(QCACHE)
106 #define	VMEM_QCACHE_IDX_MAX	32
107 
108 #define	QC_NAME_MAX	16
109 
110 struct qcache {
111 	pool_cache_t qc_cache;
112 	vmem_t *qc_vmem;
113 	char qc_name[QC_NAME_MAX];
114 };
115 typedef struct qcache qcache_t;
116 #define	QC_POOL_TO_QCACHE(pool)	((qcache_t *)(pool->pr_qcache))
117 #endif /* defined(QCACHE) */
118 
119 /* vmem arena */
120 struct vmem {
121 	LOCK_DECL(vm_lock);
122 	vmem_addr_t (*vm_allocfn)(vmem_t *, vmem_size_t, vmem_size_t *,
123 	    vm_flag_t);
124 	void (*vm_freefn)(vmem_t *, vmem_addr_t, vmem_size_t);
125 	vmem_t *vm_source;
126 	struct vmem_seglist vm_seglist;
127 	struct vmem_freelist vm_freelist[VMEM_MAXORDER];
128 	size_t vm_hashsize;
129 	size_t vm_nbusytag;
130 	struct vmem_hashlist *vm_hashlist;
131 	size_t vm_quantum_mask;
132 	int vm_quantum_shift;
133 	const char *vm_name;
134 	LIST_ENTRY(vmem) vm_alllist;
135 
136 #if defined(QCACHE)
137 	/* quantum cache */
138 	size_t vm_qcache_max;
139 	struct pool_allocator vm_qcache_allocator;
140 	qcache_t vm_qcache_store[VMEM_QCACHE_IDX_MAX];
141 	qcache_t *vm_qcache[VMEM_QCACHE_IDX_MAX];
142 #endif /* defined(QCACHE) */
143 };
144 
145 #define	VMEM_LOCK(vm)		mutex_enter(&vm->vm_lock)
146 #define	VMEM_TRYLOCK(vm)	mutex_tryenter(&vm->vm_lock)
147 #define	VMEM_UNLOCK(vm)		mutex_exit(&vm->vm_lock)
148 #define	VMEM_LOCK_INIT(vm, ipl)	mutex_init(&vm->vm_lock, MUTEX_DEFAULT, ipl)
149 #define	VMEM_LOCK_DESTROY(vm)	mutex_destroy(&vm->vm_lock)
150 #define	VMEM_ASSERT_LOCKED(vm)	KASSERT(mutex_owned(&vm->vm_lock))
151 
152 /* boundary tag */
153 struct vmem_btag {
154 	CIRCLEQ_ENTRY(vmem_btag) bt_seglist;
155 	union {
156 		LIST_ENTRY(vmem_btag) u_freelist; /* BT_TYPE_FREE */
157 		LIST_ENTRY(vmem_btag) u_hashlist; /* BT_TYPE_BUSY */
158 	} bt_u;
159 #define	bt_hashlist	bt_u.u_hashlist
160 #define	bt_freelist	bt_u.u_freelist
161 	vmem_addr_t bt_start;
162 	vmem_size_t bt_size;
163 	int bt_type;
164 };
165 
166 #define	BT_TYPE_SPAN		1
167 #define	BT_TYPE_SPAN_STATIC	2
168 #define	BT_TYPE_FREE		3
169 #define	BT_TYPE_BUSY		4
170 #define	BT_ISSPAN_P(bt)	((bt)->bt_type <= BT_TYPE_SPAN_STATIC)
171 
172 #define	BT_END(bt)	((bt)->bt_start + (bt)->bt_size)
173 
174 typedef struct vmem_btag bt_t;
175 
176 /* ---- misc */
177 
178 #define	VMEM_ALIGNUP(addr, align) \
179 	(-(-(addr) & -(align)))
180 #define	VMEM_CROSS_P(addr1, addr2, boundary) \
181 	((((addr1) ^ (addr2)) & -(boundary)) != 0)
182 
183 #define	ORDER2SIZE(order)	((vmem_size_t)1 << (order))
184 
185 static int
186 calc_order(vmem_size_t size)
187 {
188 	vmem_size_t target;
189 	int i;
190 
191 	KASSERT(size != 0);
192 
193 	i = 0;
194 	target = size >> 1;
195 	while (ORDER2SIZE(i) <= target) {
196 		i++;
197 	}
198 
199 	KASSERT(ORDER2SIZE(i) <= size);
200 	KASSERT(size < ORDER2SIZE(i + 1) || ORDER2SIZE(i + 1) < ORDER2SIZE(i));
201 
202 	return i;
203 }
204 
205 #if defined(_KERNEL)
206 static MALLOC_DEFINE(M_VMEM, "vmem", "vmem");
207 #endif /* defined(_KERNEL) */
208 
209 static void *
210 xmalloc(size_t sz, vm_flag_t flags)
211 {
212 
213 #if defined(_KERNEL)
214 	return malloc(sz, M_VMEM,
215 	    M_CANFAIL | ((flags & VM_SLEEP) ? M_WAITOK : M_NOWAIT));
216 #else /* defined(_KERNEL) */
217 	return malloc(sz);
218 #endif /* defined(_KERNEL) */
219 }
220 
221 static void
222 xfree(void *p)
223 {
224 
225 #if defined(_KERNEL)
226 	return free(p, M_VMEM);
227 #else /* defined(_KERNEL) */
228 	return free(p);
229 #endif /* defined(_KERNEL) */
230 }
231 
232 /* ---- boundary tag */
233 
234 #if defined(_KERNEL)
235 static struct pool_cache bt_cache;
236 #endif /* defined(_KERNEL) */
237 
238 static bt_t *
239 bt_alloc(vmem_t *vm, vm_flag_t flags)
240 {
241 	bt_t *bt;
242 
243 #if defined(_KERNEL)
244 	bt = pool_cache_get(&bt_cache,
245 	    (flags & VM_SLEEP) != 0 ? PR_WAITOK : PR_NOWAIT);
246 #else /* defined(_KERNEL) */
247 	bt = malloc(sizeof *bt);
248 #endif /* defined(_KERNEL) */
249 
250 	return bt;
251 }
252 
253 static void
254 bt_free(vmem_t *vm, bt_t *bt)
255 {
256 
257 #if defined(_KERNEL)
258 	pool_cache_put(&bt_cache, bt);
259 #else /* defined(_KERNEL) */
260 	free(bt);
261 #endif /* defined(_KERNEL) */
262 }
263 
264 /*
265  * freelist[0] ... [1, 1]
266  * freelist[1] ... [2, 3]
267  * freelist[2] ... [4, 7]
268  * freelist[3] ... [8, 15]
269  *  :
270  * freelist[n] ... [(1 << n), (1 << (n + 1)) - 1]
271  *  :
272  */
273 
274 static struct vmem_freelist *
275 bt_freehead_tofree(vmem_t *vm, vmem_size_t size)
276 {
277 	const vmem_size_t qsize = size >> vm->vm_quantum_shift;
278 	int idx;
279 
280 	KASSERT((size & vm->vm_quantum_mask) == 0);
281 	KASSERT(size != 0);
282 
283 	idx = calc_order(qsize);
284 	KASSERT(idx >= 0);
285 	KASSERT(idx < VMEM_MAXORDER);
286 
287 	return &vm->vm_freelist[idx];
288 }
289 
290 static struct vmem_freelist *
291 bt_freehead_toalloc(vmem_t *vm, vmem_size_t size, vm_flag_t strat)
292 {
293 	const vmem_size_t qsize = size >> vm->vm_quantum_shift;
294 	int idx;
295 
296 	KASSERT((size & vm->vm_quantum_mask) == 0);
297 	KASSERT(size != 0);
298 
299 	idx = calc_order(qsize);
300 	if (strat == VM_INSTANTFIT && ORDER2SIZE(idx) != qsize) {
301 		idx++;
302 		/* check too large request? */
303 	}
304 	KASSERT(idx >= 0);
305 	KASSERT(idx < VMEM_MAXORDER);
306 
307 	return &vm->vm_freelist[idx];
308 }
309 
310 /* ---- boundary tag hash */
311 
312 static struct vmem_hashlist *
313 bt_hashhead(vmem_t *vm, vmem_addr_t addr)
314 {
315 	struct vmem_hashlist *list;
316 	unsigned int hash;
317 
318 	hash = hash32_buf(&addr, sizeof(addr), HASH32_BUF_INIT);
319 	list = &vm->vm_hashlist[hash % vm->vm_hashsize];
320 
321 	return list;
322 }
323 
324 static bt_t *
325 bt_lookupbusy(vmem_t *vm, vmem_addr_t addr)
326 {
327 	struct vmem_hashlist *list;
328 	bt_t *bt;
329 
330 	list = bt_hashhead(vm, addr);
331 	LIST_FOREACH(bt, list, bt_hashlist) {
332 		if (bt->bt_start == addr) {
333 			break;
334 		}
335 	}
336 
337 	return bt;
338 }
339 
340 static void
341 bt_rembusy(vmem_t *vm, bt_t *bt)
342 {
343 
344 	KASSERT(vm->vm_nbusytag > 0);
345 	vm->vm_nbusytag--;
346 	LIST_REMOVE(bt, bt_hashlist);
347 }
348 
349 static void
350 bt_insbusy(vmem_t *vm, bt_t *bt)
351 {
352 	struct vmem_hashlist *list;
353 
354 	KASSERT(bt->bt_type == BT_TYPE_BUSY);
355 
356 	list = bt_hashhead(vm, bt->bt_start);
357 	LIST_INSERT_HEAD(list, bt, bt_hashlist);
358 	vm->vm_nbusytag++;
359 }
360 
361 /* ---- boundary tag list */
362 
363 static void
364 bt_remseg(vmem_t *vm, bt_t *bt)
365 {
366 
367 	CIRCLEQ_REMOVE(&vm->vm_seglist, bt, bt_seglist);
368 }
369 
370 static void
371 bt_insseg(vmem_t *vm, bt_t *bt, bt_t *prev)
372 {
373 
374 	CIRCLEQ_INSERT_AFTER(&vm->vm_seglist, prev, bt, bt_seglist);
375 }
376 
377 static void
378 bt_insseg_tail(vmem_t *vm, bt_t *bt)
379 {
380 
381 	CIRCLEQ_INSERT_TAIL(&vm->vm_seglist, bt, bt_seglist);
382 }
383 
384 static void
385 bt_remfree(vmem_t *vm, bt_t *bt)
386 {
387 
388 	KASSERT(bt->bt_type == BT_TYPE_FREE);
389 
390 	LIST_REMOVE(bt, bt_freelist);
391 }
392 
393 static void
394 bt_insfree(vmem_t *vm, bt_t *bt)
395 {
396 	struct vmem_freelist *list;
397 
398 	list = bt_freehead_tofree(vm, bt->bt_size);
399 	LIST_INSERT_HEAD(list, bt, bt_freelist);
400 }
401 
402 /* ---- vmem internal functions */
403 
404 #if defined(_KERNEL)
405 static kmutex_t vmem_list_lock;
406 static LIST_HEAD(, vmem) vmem_list = LIST_HEAD_INITIALIZER(vmem_list);
407 #endif /* defined(_KERNEL) */
408 
409 #if defined(QCACHE)
410 static inline vm_flag_t
411 prf_to_vmf(int prflags)
412 {
413 	vm_flag_t vmflags;
414 
415 	KASSERT((prflags & ~(PR_LIMITFAIL | PR_WAITOK | PR_NOWAIT)) == 0);
416 	if ((prflags & PR_WAITOK) != 0) {
417 		vmflags = VM_SLEEP;
418 	} else {
419 		vmflags = VM_NOSLEEP;
420 	}
421 	return vmflags;
422 }
423 
424 static inline int
425 vmf_to_prf(vm_flag_t vmflags)
426 {
427 	int prflags;
428 
429 	if ((vmflags & VM_SLEEP) != 0) {
430 		prflags = PR_WAITOK;
431 	} else {
432 		prflags = PR_NOWAIT;
433 	}
434 	return prflags;
435 }
436 
437 static size_t
438 qc_poolpage_size(size_t qcache_max)
439 {
440 	int i;
441 
442 	for (i = 0; ORDER2SIZE(i) <= qcache_max * 3; i++) {
443 		/* nothing */
444 	}
445 	return ORDER2SIZE(i);
446 }
447 
448 static void *
449 qc_poolpage_alloc(struct pool *pool, int prflags)
450 {
451 	qcache_t *qc = QC_POOL_TO_QCACHE(pool);
452 	vmem_t *vm = qc->qc_vmem;
453 
454 	return (void *)vmem_alloc(vm, pool->pr_alloc->pa_pagesz,
455 	    prf_to_vmf(prflags) | VM_INSTANTFIT);
456 }
457 
458 static void
459 qc_poolpage_free(struct pool *pool, void *addr)
460 {
461 	qcache_t *qc = QC_POOL_TO_QCACHE(pool);
462 	vmem_t *vm = qc->qc_vmem;
463 
464 	vmem_free(vm, (vmem_addr_t)addr, pool->pr_alloc->pa_pagesz);
465 }
466 
467 static void
468 qc_init(vmem_t *vm, size_t qcache_max, int ipl)
469 {
470 	qcache_t *prevqc;
471 	struct pool_allocator *pa;
472 	int qcache_idx_max;
473 	int i;
474 
475 	KASSERT((qcache_max & vm->vm_quantum_mask) == 0);
476 	if (qcache_max > (VMEM_QCACHE_IDX_MAX << vm->vm_quantum_shift)) {
477 		qcache_max = VMEM_QCACHE_IDX_MAX << vm->vm_quantum_shift;
478 	}
479 	vm->vm_qcache_max = qcache_max;
480 	pa = &vm->vm_qcache_allocator;
481 	memset(pa, 0, sizeof(*pa));
482 	pa->pa_alloc = qc_poolpage_alloc;
483 	pa->pa_free = qc_poolpage_free;
484 	pa->pa_pagesz = qc_poolpage_size(qcache_max);
485 
486 	qcache_idx_max = qcache_max >> vm->vm_quantum_shift;
487 	prevqc = NULL;
488 	for (i = qcache_idx_max; i > 0; i--) {
489 		qcache_t *qc = &vm->vm_qcache_store[i - 1];
490 		size_t size = i << vm->vm_quantum_shift;
491 
492 		qc->qc_vmem = vm;
493 		snprintf(qc->qc_name, sizeof(qc->qc_name), "%s-%zu",
494 		    vm->vm_name, size);
495 		qc->qc_cache = pool_cache_init(size,
496 		    ORDER2SIZE(vm->vm_quantum_shift), 0,
497 		    PR_NOALIGN | PR_NOTOUCH /* XXX */,
498 		    qc->qc_name, pa, ipl, NULL, NULL, NULL);
499 		KASSERT(qc->qc_cache != NULL);	/* XXX */
500 		if (prevqc != NULL &&
501 		    qc->qc_cache->pc_pool.pr_itemsperpage ==
502 		    prevqc->qc_cache->pc_pool.pr_itemsperpage) {
503 			pool_cache_destroy(qc->qc_cache);
504 			vm->vm_qcache[i - 1] = prevqc;
505 			continue;
506 		}
507 		qc->qc_cache->pc_pool.pr_qcache = qc;
508 		vm->vm_qcache[i - 1] = qc;
509 		prevqc = qc;
510 	}
511 }
512 
513 static void
514 qc_destroy(vmem_t *vm)
515 {
516 	const qcache_t *prevqc;
517 	int i;
518 	int qcache_idx_max;
519 
520 	qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift;
521 	prevqc = NULL;
522 	for (i = 0; i < qcache_idx_max; i++) {
523 		qcache_t *qc = vm->vm_qcache[i];
524 
525 		if (prevqc == qc) {
526 			continue;
527 		}
528 		pool_cache_destroy(qc->qc_cache);
529 		prevqc = qc;
530 	}
531 }
532 
533 static bool
534 qc_reap(vmem_t *vm)
535 {
536 	const qcache_t *prevqc;
537 	int i;
538 	int qcache_idx_max;
539 	bool didsomething = false;
540 
541 	qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift;
542 	prevqc = NULL;
543 	for (i = 0; i < qcache_idx_max; i++) {
544 		qcache_t *qc = vm->vm_qcache[i];
545 
546 		if (prevqc == qc) {
547 			continue;
548 		}
549 		if (pool_cache_reclaim(qc->qc_cache) != 0) {
550 			didsomething = true;
551 		}
552 		prevqc = qc;
553 	}
554 
555 	return didsomething;
556 }
557 #endif /* defined(QCACHE) */
558 
559 #if defined(_KERNEL)
560 static int
561 vmem_init(void)
562 {
563 
564 	mutex_init(&vmem_list_lock, MUTEX_DEFAULT, IPL_NONE);
565 	pool_cache_bootstrap(&bt_cache, sizeof(bt_t), 0, 0, 0, "vmembt",
566 	    NULL, IPL_VM, NULL, NULL, NULL);
567 	return 0;
568 }
569 #endif /* defined(_KERNEL) */
570 
571 static vmem_addr_t
572 vmem_add1(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, vm_flag_t flags,
573     int spanbttype)
574 {
575 	bt_t *btspan;
576 	bt_t *btfree;
577 
578 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
579 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
580 
581 	btspan = bt_alloc(vm, flags);
582 	if (btspan == NULL) {
583 		return VMEM_ADDR_NULL;
584 	}
585 	btfree = bt_alloc(vm, flags);
586 	if (btfree == NULL) {
587 		bt_free(vm, btspan);
588 		return VMEM_ADDR_NULL;
589 	}
590 
591 	btspan->bt_type = spanbttype;
592 	btspan->bt_start = addr;
593 	btspan->bt_size = size;
594 
595 	btfree->bt_type = BT_TYPE_FREE;
596 	btfree->bt_start = addr;
597 	btfree->bt_size = size;
598 
599 	VMEM_LOCK(vm);
600 	bt_insseg_tail(vm, btspan);
601 	bt_insseg(vm, btfree, btspan);
602 	bt_insfree(vm, btfree);
603 	VMEM_UNLOCK(vm);
604 
605 	return addr;
606 }
607 
608 static void
609 vmem_destroy1(vmem_t *vm)
610 {
611 
612 #if defined(QCACHE)
613 	qc_destroy(vm);
614 #endif /* defined(QCACHE) */
615 	if (vm->vm_hashlist != NULL) {
616 		int i;
617 
618 		for (i = 0; i < vm->vm_hashsize; i++) {
619 			bt_t *bt;
620 
621 			while ((bt = LIST_FIRST(&vm->vm_hashlist[i])) != NULL) {
622 				KASSERT(bt->bt_type == BT_TYPE_SPAN_STATIC);
623 				bt_free(vm, bt);
624 			}
625 		}
626 		xfree(vm->vm_hashlist);
627 	}
628 	VMEM_LOCK_DESTROY(vm);
629 	xfree(vm);
630 }
631 
632 static int
633 vmem_import(vmem_t *vm, vmem_size_t size, vm_flag_t flags)
634 {
635 	vmem_addr_t addr;
636 
637 	if (vm->vm_allocfn == NULL) {
638 		return EINVAL;
639 	}
640 
641 	addr = (*vm->vm_allocfn)(vm->vm_source, size, &size, flags);
642 	if (addr == VMEM_ADDR_NULL) {
643 		return ENOMEM;
644 	}
645 
646 	if (vmem_add1(vm, addr, size, flags, BT_TYPE_SPAN) == VMEM_ADDR_NULL) {
647 		(*vm->vm_freefn)(vm->vm_source, addr, size);
648 		return ENOMEM;
649 	}
650 
651 	return 0;
652 }
653 
654 static int
655 vmem_rehash(vmem_t *vm, size_t newhashsize, vm_flag_t flags)
656 {
657 	bt_t *bt;
658 	int i;
659 	struct vmem_hashlist *newhashlist;
660 	struct vmem_hashlist *oldhashlist;
661 	size_t oldhashsize;
662 
663 	KASSERT(newhashsize > 0);
664 
665 	newhashlist =
666 	    xmalloc(sizeof(struct vmem_hashlist *) * newhashsize, flags);
667 	if (newhashlist == NULL) {
668 		return ENOMEM;
669 	}
670 	for (i = 0; i < newhashsize; i++) {
671 		LIST_INIT(&newhashlist[i]);
672 	}
673 
674 	if (!VMEM_TRYLOCK(vm)) {
675 		xfree(newhashlist);
676 		return EBUSY;
677 	}
678 	oldhashlist = vm->vm_hashlist;
679 	oldhashsize = vm->vm_hashsize;
680 	vm->vm_hashlist = newhashlist;
681 	vm->vm_hashsize = newhashsize;
682 	if (oldhashlist == NULL) {
683 		VMEM_UNLOCK(vm);
684 		return 0;
685 	}
686 	for (i = 0; i < oldhashsize; i++) {
687 		while ((bt = LIST_FIRST(&oldhashlist[i])) != NULL) {
688 			bt_rembusy(vm, bt); /* XXX */
689 			bt_insbusy(vm, bt);
690 		}
691 	}
692 	VMEM_UNLOCK(vm);
693 
694 	xfree(oldhashlist);
695 
696 	return 0;
697 }
698 
699 /*
700  * vmem_fit: check if a bt can satisfy the given restrictions.
701  */
702 
703 static vmem_addr_t
704 vmem_fit(const bt_t *bt, vmem_size_t size, vmem_size_t align, vmem_size_t phase,
705     vmem_size_t nocross, vmem_addr_t minaddr, vmem_addr_t maxaddr)
706 {
707 	vmem_addr_t start;
708 	vmem_addr_t end;
709 
710 	KASSERT(bt->bt_size >= size);
711 
712 	/*
713 	 * XXX assumption: vmem_addr_t and vmem_size_t are
714 	 * unsigned integer of the same size.
715 	 */
716 
717 	start = bt->bt_start;
718 	if (start < minaddr) {
719 		start = minaddr;
720 	}
721 	end = BT_END(bt);
722 	if (end > maxaddr - 1) {
723 		end = maxaddr - 1;
724 	}
725 	if (start >= end) {
726 		return VMEM_ADDR_NULL;
727 	}
728 
729 	start = VMEM_ALIGNUP(start - phase, align) + phase;
730 	if (start < bt->bt_start) {
731 		start += align;
732 	}
733 	if (VMEM_CROSS_P(start, start + size - 1, nocross)) {
734 		KASSERT(align < nocross);
735 		start = VMEM_ALIGNUP(start - phase, nocross) + phase;
736 	}
737 	if (start < end && end - start >= size) {
738 		KASSERT((start & (align - 1)) == phase);
739 		KASSERT(!VMEM_CROSS_P(start, start + size - 1, nocross));
740 		KASSERT(minaddr <= start);
741 		KASSERT(maxaddr == 0 || start + size <= maxaddr);
742 		KASSERT(bt->bt_start <= start);
743 		KASSERT(start + size <= BT_END(bt));
744 		return start;
745 	}
746 	return VMEM_ADDR_NULL;
747 }
748 
749 /* ---- vmem API */
750 
751 /*
752  * vmem_create: create an arena.
753  *
754  * => must not be called from interrupt context.
755  */
756 
757 vmem_t *
758 vmem_create(const char *name, vmem_addr_t base, vmem_size_t size,
759     vmem_size_t quantum,
760     vmem_addr_t (*allocfn)(vmem_t *, vmem_size_t, vmem_size_t *, vm_flag_t),
761     void (*freefn)(vmem_t *, vmem_addr_t, vmem_size_t),
762     vmem_t *source, vmem_size_t qcache_max, vm_flag_t flags,
763     int ipl)
764 {
765 	vmem_t *vm;
766 	int i;
767 #if defined(_KERNEL)
768 	static ONCE_DECL(control);
769 #endif /* defined(_KERNEL) */
770 
771 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
772 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
773 
774 #if defined(_KERNEL)
775 	if (RUN_ONCE(&control, vmem_init)) {
776 		return NULL;
777 	}
778 #endif /* defined(_KERNEL) */
779 	vm = xmalloc(sizeof(*vm), flags);
780 	if (vm == NULL) {
781 		return NULL;
782 	}
783 
784 	VMEM_LOCK_INIT(vm, ipl);
785 	vm->vm_name = name;
786 	vm->vm_quantum_mask = quantum - 1;
787 	vm->vm_quantum_shift = calc_order(quantum);
788 	KASSERT(ORDER2SIZE(vm->vm_quantum_shift) == quantum);
789 	vm->vm_allocfn = allocfn;
790 	vm->vm_freefn = freefn;
791 	vm->vm_source = source;
792 	vm->vm_nbusytag = 0;
793 #if defined(QCACHE)
794 	qc_init(vm, qcache_max, ipl);
795 #endif /* defined(QCACHE) */
796 
797 	CIRCLEQ_INIT(&vm->vm_seglist);
798 	for (i = 0; i < VMEM_MAXORDER; i++) {
799 		LIST_INIT(&vm->vm_freelist[i]);
800 	}
801 	vm->vm_hashlist = NULL;
802 	if (vmem_rehash(vm, VMEM_HASHSIZE_INIT, flags)) {
803 		vmem_destroy1(vm);
804 		return NULL;
805 	}
806 
807 	if (size != 0) {
808 		if (vmem_add(vm, base, size, flags) == 0) {
809 			vmem_destroy1(vm);
810 			return NULL;
811 		}
812 	}
813 
814 #if defined(_KERNEL)
815 	mutex_enter(&vmem_list_lock);
816 	LIST_INSERT_HEAD(&vmem_list, vm, vm_alllist);
817 	mutex_exit(&vmem_list_lock);
818 #endif /* defined(_KERNEL) */
819 
820 	return vm;
821 }
822 
823 void
824 vmem_destroy(vmem_t *vm)
825 {
826 
827 #if defined(_KERNEL)
828 	mutex_enter(&vmem_list_lock);
829 	LIST_REMOVE(vm, vm_alllist);
830 	mutex_exit(&vmem_list_lock);
831 #endif /* defined(_KERNEL) */
832 
833 	vmem_destroy1(vm);
834 }
835 
836 vmem_size_t
837 vmem_roundup_size(vmem_t *vm, vmem_size_t size)
838 {
839 
840 	return (size + vm->vm_quantum_mask) & ~vm->vm_quantum_mask;
841 }
842 
843 /*
844  * vmem_alloc:
845  *
846  * => caller must ensure appropriate spl,
847  *    if the arena can be accessed from interrupt context.
848  */
849 
850 vmem_addr_t
851 vmem_alloc(vmem_t *vm, vmem_size_t size0, vm_flag_t flags)
852 {
853 	const vmem_size_t size __unused = vmem_roundup_size(vm, size0);
854 	const vm_flag_t strat __unused = flags & VM_FITMASK;
855 
856 	KASSERT((flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
857 	KASSERT((~flags & (VM_SLEEP|VM_NOSLEEP)) != 0);
858 
859 	KASSERT(size0 > 0);
860 	KASSERT(size > 0);
861 	KASSERT(strat == VM_BESTFIT || strat == VM_INSTANTFIT);
862 	if ((flags & VM_SLEEP) != 0) {
863 		ASSERT_SLEEPABLE(NULL, __func__);
864 	}
865 
866 #if defined(QCACHE)
867 	if (size <= vm->vm_qcache_max) {
868 		int qidx = size >> vm->vm_quantum_shift;
869 		qcache_t *qc = vm->vm_qcache[qidx - 1];
870 
871 		return (vmem_addr_t)pool_cache_get(qc->qc_cache,
872 		    vmf_to_prf(flags));
873 	}
874 #endif /* defined(QCACHE) */
875 
876 	return vmem_xalloc(vm, size0, 0, 0, 0, 0, 0, flags);
877 }
878 
879 vmem_addr_t
880 vmem_xalloc(vmem_t *vm, vmem_size_t size0, vmem_size_t align, vmem_size_t phase,
881     vmem_size_t nocross, vmem_addr_t minaddr, vmem_addr_t maxaddr,
882     vm_flag_t flags)
883 {
884 	struct vmem_freelist *list;
885 	struct vmem_freelist *first;
886 	struct vmem_freelist *end;
887 	bt_t *bt;
888 	bt_t *btnew;
889 	bt_t *btnew2;
890 	const vmem_size_t size = vmem_roundup_size(vm, size0);
891 	vm_flag_t strat = flags & VM_FITMASK;
892 	vmem_addr_t start;
893 
894 	KASSERT(size0 > 0);
895 	KASSERT(size > 0);
896 	KASSERT(strat == VM_BESTFIT || strat == VM_INSTANTFIT);
897 	if ((flags & VM_SLEEP) != 0) {
898 		ASSERT_SLEEPABLE(NULL, __func__);
899 	}
900 	KASSERT((align & vm->vm_quantum_mask) == 0);
901 	KASSERT((align & (align - 1)) == 0);
902 	KASSERT((phase & vm->vm_quantum_mask) == 0);
903 	KASSERT((nocross & vm->vm_quantum_mask) == 0);
904 	KASSERT((nocross & (nocross - 1)) == 0);
905 	KASSERT((align == 0 && phase == 0) || phase < align);
906 	KASSERT(nocross == 0 || nocross >= size);
907 	KASSERT(maxaddr == 0 || minaddr < maxaddr);
908 	KASSERT(!VMEM_CROSS_P(phase, phase + size - 1, nocross));
909 
910 	if (align == 0) {
911 		align = vm->vm_quantum_mask + 1;
912 	}
913 	btnew = bt_alloc(vm, flags);
914 	if (btnew == NULL) {
915 		return VMEM_ADDR_NULL;
916 	}
917 	btnew2 = bt_alloc(vm, flags); /* XXX not necessary if no restrictions */
918 	if (btnew2 == NULL) {
919 		bt_free(vm, btnew);
920 		return VMEM_ADDR_NULL;
921 	}
922 
923 retry_strat:
924 	first = bt_freehead_toalloc(vm, size, strat);
925 	end = &vm->vm_freelist[VMEM_MAXORDER];
926 retry:
927 	bt = NULL;
928 	VMEM_LOCK(vm);
929 	if (strat == VM_INSTANTFIT) {
930 		for (list = first; list < end; list++) {
931 			bt = LIST_FIRST(list);
932 			if (bt != NULL) {
933 				start = vmem_fit(bt, size, align, phase,
934 				    nocross, minaddr, maxaddr);
935 				if (start != VMEM_ADDR_NULL) {
936 					goto gotit;
937 				}
938 			}
939 		}
940 	} else { /* VM_BESTFIT */
941 		for (list = first; list < end; list++) {
942 			LIST_FOREACH(bt, list, bt_freelist) {
943 				if (bt->bt_size >= size) {
944 					start = vmem_fit(bt, size, align, phase,
945 					    nocross, minaddr, maxaddr);
946 					if (start != VMEM_ADDR_NULL) {
947 						goto gotit;
948 					}
949 				}
950 			}
951 		}
952 	}
953 	VMEM_UNLOCK(vm);
954 #if 1
955 	if (strat == VM_INSTANTFIT) {
956 		strat = VM_BESTFIT;
957 		goto retry_strat;
958 	}
959 #endif
960 	if (align != vm->vm_quantum_mask + 1 || phase != 0 ||
961 	    nocross != 0 || minaddr != 0 || maxaddr != 0) {
962 
963 		/*
964 		 * XXX should try to import a region large enough to
965 		 * satisfy restrictions?
966 		 */
967 
968 		goto fail;
969 	}
970 	if (vmem_import(vm, size, flags) == 0) {
971 		goto retry;
972 	}
973 	/* XXX */
974 fail:
975 	bt_free(vm, btnew);
976 	bt_free(vm, btnew2);
977 	return VMEM_ADDR_NULL;
978 
979 gotit:
980 	KASSERT(bt->bt_type == BT_TYPE_FREE);
981 	KASSERT(bt->bt_size >= size);
982 	bt_remfree(vm, bt);
983 	if (bt->bt_start != start) {
984 		btnew2->bt_type = BT_TYPE_FREE;
985 		btnew2->bt_start = bt->bt_start;
986 		btnew2->bt_size = start - bt->bt_start;
987 		bt->bt_start = start;
988 		bt->bt_size -= btnew2->bt_size;
989 		bt_insfree(vm, btnew2);
990 		bt_insseg(vm, btnew2, CIRCLEQ_PREV(bt, bt_seglist));
991 		btnew2 = NULL;
992 	}
993 	KASSERT(bt->bt_start == start);
994 	if (bt->bt_size != size && bt->bt_size - size > vm->vm_quantum_mask) {
995 		/* split */
996 		btnew->bt_type = BT_TYPE_BUSY;
997 		btnew->bt_start = bt->bt_start;
998 		btnew->bt_size = size;
999 		bt->bt_start = bt->bt_start + size;
1000 		bt->bt_size -= size;
1001 		bt_insfree(vm, bt);
1002 		bt_insseg(vm, btnew, CIRCLEQ_PREV(bt, bt_seglist));
1003 		bt_insbusy(vm, btnew);
1004 		VMEM_UNLOCK(vm);
1005 	} else {
1006 		bt->bt_type = BT_TYPE_BUSY;
1007 		bt_insbusy(vm, bt);
1008 		VMEM_UNLOCK(vm);
1009 		bt_free(vm, btnew);
1010 		btnew = bt;
1011 	}
1012 	if (btnew2 != NULL) {
1013 		bt_free(vm, btnew2);
1014 	}
1015 	KASSERT(btnew->bt_size >= size);
1016 	btnew->bt_type = BT_TYPE_BUSY;
1017 
1018 	return btnew->bt_start;
1019 }
1020 
1021 /*
1022  * vmem_free:
1023  *
1024  * => caller must ensure appropriate spl,
1025  *    if the arena can be accessed from interrupt context.
1026  */
1027 
1028 void
1029 vmem_free(vmem_t *vm, vmem_addr_t addr, vmem_size_t size)
1030 {
1031 
1032 	KASSERT(addr != VMEM_ADDR_NULL);
1033 	KASSERT(size > 0);
1034 
1035 #if defined(QCACHE)
1036 	if (size <= vm->vm_qcache_max) {
1037 		int qidx = (size + vm->vm_quantum_mask) >> vm->vm_quantum_shift;
1038 		qcache_t *qc = vm->vm_qcache[qidx - 1];
1039 
1040 		return pool_cache_put(qc->qc_cache, (void *)addr);
1041 	}
1042 #endif /* defined(QCACHE) */
1043 
1044 	vmem_xfree(vm, addr, size);
1045 }
1046 
1047 void
1048 vmem_xfree(vmem_t *vm, vmem_addr_t addr, vmem_size_t size)
1049 {
1050 	bt_t *bt;
1051 	bt_t *t;
1052 
1053 	KASSERT(addr != VMEM_ADDR_NULL);
1054 	KASSERT(size > 0);
1055 
1056 	VMEM_LOCK(vm);
1057 
1058 	bt = bt_lookupbusy(vm, addr);
1059 	KASSERT(bt != NULL);
1060 	KASSERT(bt->bt_start == addr);
1061 	KASSERT(bt->bt_size == vmem_roundup_size(vm, size) ||
1062 	    bt->bt_size - vmem_roundup_size(vm, size) <= vm->vm_quantum_mask);
1063 	KASSERT(bt->bt_type == BT_TYPE_BUSY);
1064 	bt_rembusy(vm, bt);
1065 	bt->bt_type = BT_TYPE_FREE;
1066 
1067 	/* coalesce */
1068 	t = CIRCLEQ_NEXT(bt, bt_seglist);
1069 	if (t != NULL && t->bt_type == BT_TYPE_FREE) {
1070 		KASSERT(BT_END(bt) == t->bt_start);
1071 		bt_remfree(vm, t);
1072 		bt_remseg(vm, t);
1073 		bt->bt_size += t->bt_size;
1074 		bt_free(vm, t);
1075 	}
1076 	t = CIRCLEQ_PREV(bt, bt_seglist);
1077 	if (t != NULL && t->bt_type == BT_TYPE_FREE) {
1078 		KASSERT(BT_END(t) == bt->bt_start);
1079 		bt_remfree(vm, t);
1080 		bt_remseg(vm, t);
1081 		bt->bt_size += t->bt_size;
1082 		bt->bt_start = t->bt_start;
1083 		bt_free(vm, t);
1084 	}
1085 
1086 	t = CIRCLEQ_PREV(bt, bt_seglist);
1087 	KASSERT(t != NULL);
1088 	KASSERT(BT_ISSPAN_P(t) || t->bt_type == BT_TYPE_BUSY);
1089 	if (vm->vm_freefn != NULL && t->bt_type == BT_TYPE_SPAN &&
1090 	    t->bt_size == bt->bt_size) {
1091 		vmem_addr_t spanaddr;
1092 		vmem_size_t spansize;
1093 
1094 		KASSERT(t->bt_start == bt->bt_start);
1095 		spanaddr = bt->bt_start;
1096 		spansize = bt->bt_size;
1097 		bt_remseg(vm, bt);
1098 		bt_free(vm, bt);
1099 		bt_remseg(vm, t);
1100 		bt_free(vm, t);
1101 		VMEM_UNLOCK(vm);
1102 		(*vm->vm_freefn)(vm->vm_source, spanaddr, spansize);
1103 	} else {
1104 		bt_insfree(vm, bt);
1105 		VMEM_UNLOCK(vm);
1106 	}
1107 }
1108 
1109 /*
1110  * vmem_add:
1111  *
1112  * => caller must ensure appropriate spl,
1113  *    if the arena can be accessed from interrupt context.
1114  */
1115 
1116 vmem_addr_t
1117 vmem_add(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, vm_flag_t flags)
1118 {
1119 
1120 	return vmem_add1(vm, addr, size, flags, BT_TYPE_SPAN_STATIC);
1121 }
1122 
1123 /*
1124  * vmem_reap: reap unused resources.
1125  *
1126  * => return true if we successfully reaped something.
1127  */
1128 
1129 bool
1130 vmem_reap(vmem_t *vm)
1131 {
1132 	bool didsomething = false;
1133 
1134 #if defined(QCACHE)
1135 	didsomething = qc_reap(vm);
1136 #endif /* defined(QCACHE) */
1137 	return didsomething;
1138 }
1139 
1140 /* ---- rehash */
1141 
1142 #if defined(_KERNEL)
1143 static struct callout vmem_rehash_ch;
1144 static int vmem_rehash_interval;
1145 static struct workqueue *vmem_rehash_wq;
1146 static struct work vmem_rehash_wk;
1147 
1148 static void
1149 vmem_rehash_all(struct work *wk, void *dummy)
1150 {
1151 	vmem_t *vm;
1152 
1153 	KASSERT(wk == &vmem_rehash_wk);
1154 	mutex_enter(&vmem_list_lock);
1155 	LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1156 		size_t desired;
1157 		size_t current;
1158 
1159 		if (!VMEM_TRYLOCK(vm)) {
1160 			continue;
1161 		}
1162 		desired = vm->vm_nbusytag;
1163 		current = vm->vm_hashsize;
1164 		VMEM_UNLOCK(vm);
1165 
1166 		if (desired > VMEM_HASHSIZE_MAX) {
1167 			desired = VMEM_HASHSIZE_MAX;
1168 		} else if (desired < VMEM_HASHSIZE_MIN) {
1169 			desired = VMEM_HASHSIZE_MIN;
1170 		}
1171 		if (desired > current * 2 || desired * 2 < current) {
1172 			vmem_rehash(vm, desired, VM_NOSLEEP);
1173 		}
1174 	}
1175 	mutex_exit(&vmem_list_lock);
1176 
1177 	callout_schedule(&vmem_rehash_ch, vmem_rehash_interval);
1178 }
1179 
1180 static void
1181 vmem_rehash_all_kick(void *dummy)
1182 {
1183 
1184 	workqueue_enqueue(vmem_rehash_wq, &vmem_rehash_wk, NULL);
1185 }
1186 
1187 void
1188 vmem_rehash_start(void)
1189 {
1190 	int error;
1191 
1192 	error = workqueue_create(&vmem_rehash_wq, "vmem_rehash",
1193 	    vmem_rehash_all, NULL, PRI_VM, IPL_SOFTCLOCK, 0);
1194 	if (error) {
1195 		panic("%s: workqueue_create %d\n", __func__, error);
1196 	}
1197 	callout_init(&vmem_rehash_ch, 0);
1198 	callout_setfunc(&vmem_rehash_ch, vmem_rehash_all_kick, NULL);
1199 
1200 	vmem_rehash_interval = hz * 10;
1201 	callout_schedule(&vmem_rehash_ch, vmem_rehash_interval);
1202 }
1203 #endif /* defined(_KERNEL) */
1204 
1205 /* ---- debug */
1206 
1207 #if defined(DDB)
1208 static bt_t *
1209 vmem_whatis_lookup(vmem_t *vm, uintptr_t addr)
1210 {
1211 	int i;
1212 
1213 	for (i = 0; i < vm->vm_hashsize; i++) {
1214 		bt_t *bt;
1215 
1216 		LIST_FOREACH(bt, &vm->vm_hashlist[i], bt_hashlist) {
1217 			if (bt->bt_start <= addr && addr < BT_END(bt)) {
1218 				return bt;
1219 			}
1220 		}
1221 	}
1222 
1223 	return NULL;
1224 }
1225 
1226 void
1227 vmem_whatis(uintptr_t addr, void (*pr)(const char *, ...))
1228 {
1229 	vmem_t *vm;
1230 
1231 	LIST_FOREACH(vm, &vmem_list, vm_alllist) {
1232 		bt_t *bt;
1233 
1234 		bt = vmem_whatis_lookup(vm, addr);
1235 		if (bt == NULL) {
1236 			continue;
1237 		}
1238 		(*pr)("%p is %p+%zu from VMEM '%s'\n",
1239 		    (void *)addr, (void *)bt->bt_start,
1240 		    (size_t)(addr - bt->bt_start), vm->vm_name);
1241 	}
1242 }
1243 #endif /* defined(DDB) */
1244 
1245 #if defined(VMEM_DEBUG)
1246 
1247 #if !defined(_KERNEL)
1248 #include <stdio.h>
1249 #endif /* !defined(_KERNEL) */
1250 
1251 void bt_dump(const bt_t *);
1252 
1253 void
1254 bt_dump(const bt_t *bt)
1255 {
1256 
1257 	printf("\t%p: %" PRIu64 ", %" PRIu64 ", %d\n",
1258 	    bt, (uint64_t)bt->bt_start, (uint64_t)bt->bt_size,
1259 	    bt->bt_type);
1260 }
1261 
1262 void
1263 vmem_dump(const vmem_t *vm)
1264 {
1265 	const bt_t *bt;
1266 	int i;
1267 
1268 	printf("vmem %p '%s'\n", vm, vm->vm_name);
1269 	CIRCLEQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
1270 		bt_dump(bt);
1271 	}
1272 
1273 	for (i = 0; i < VMEM_MAXORDER; i++) {
1274 		const struct vmem_freelist *fl = &vm->vm_freelist[i];
1275 
1276 		if (LIST_EMPTY(fl)) {
1277 			continue;
1278 		}
1279 
1280 		printf("freelist[%d]\n", i);
1281 		LIST_FOREACH(bt, fl, bt_freelist) {
1282 			bt_dump(bt);
1283 			if (bt->bt_size) {
1284 			}
1285 		}
1286 	}
1287 }
1288 
1289 #if !defined(_KERNEL)
1290 
1291 int
1292 main()
1293 {
1294 	vmem_t *vm;
1295 	vmem_addr_t p;
1296 	struct reg {
1297 		vmem_addr_t p;
1298 		vmem_size_t sz;
1299 		bool x;
1300 	} *reg = NULL;
1301 	int nreg = 0;
1302 	int nalloc = 0;
1303 	int nfree = 0;
1304 	vmem_size_t total = 0;
1305 #if 1
1306 	vm_flag_t strat = VM_INSTANTFIT;
1307 #else
1308 	vm_flag_t strat = VM_BESTFIT;
1309 #endif
1310 
1311 	vm = vmem_create("test", VMEM_ADDR_NULL, 0, 1,
1312 	    NULL, NULL, NULL, 0, VM_SLEEP);
1313 	if (vm == NULL) {
1314 		printf("vmem_create\n");
1315 		exit(EXIT_FAILURE);
1316 	}
1317 	vmem_dump(vm);
1318 
1319 	p = vmem_add(vm, 100, 200, VM_SLEEP);
1320 	p = vmem_add(vm, 2000, 1, VM_SLEEP);
1321 	p = vmem_add(vm, 40000, 0x10000000>>12, VM_SLEEP);
1322 	p = vmem_add(vm, 10000, 10000, VM_SLEEP);
1323 	p = vmem_add(vm, 500, 1000, VM_SLEEP);
1324 	vmem_dump(vm);
1325 	for (;;) {
1326 		struct reg *r;
1327 		int t = rand() % 100;
1328 
1329 		if (t > 45) {
1330 			/* alloc */
1331 			vmem_size_t sz = rand() % 500 + 1;
1332 			bool x;
1333 			vmem_size_t align, phase, nocross;
1334 			vmem_addr_t minaddr, maxaddr;
1335 
1336 			if (t > 70) {
1337 				x = true;
1338 				/* XXX */
1339 				align = 1 << (rand() % 15);
1340 				phase = rand() % 65536;
1341 				nocross = 1 << (rand() % 15);
1342 				if (align <= phase) {
1343 					phase = 0;
1344 				}
1345 				if (VMEM_CROSS_P(phase, phase + sz - 1,
1346 				    nocross)) {
1347 					nocross = 0;
1348 				}
1349 				minaddr = rand() % 50000;
1350 				maxaddr = rand() % 70000;
1351 				if (minaddr > maxaddr) {
1352 					minaddr = 0;
1353 					maxaddr = 0;
1354 				}
1355 				printf("=== xalloc %" PRIu64
1356 				    " align=%" PRIu64 ", phase=%" PRIu64
1357 				    ", nocross=%" PRIu64 ", min=%" PRIu64
1358 				    ", max=%" PRIu64 "\n",
1359 				    (uint64_t)sz,
1360 				    (uint64_t)align,
1361 				    (uint64_t)phase,
1362 				    (uint64_t)nocross,
1363 				    (uint64_t)minaddr,
1364 				    (uint64_t)maxaddr);
1365 				p = vmem_xalloc(vm, sz, align, phase, nocross,
1366 				    minaddr, maxaddr, strat|VM_SLEEP);
1367 			} else {
1368 				x = false;
1369 				printf("=== alloc %" PRIu64 "\n", (uint64_t)sz);
1370 				p = vmem_alloc(vm, sz, strat|VM_SLEEP);
1371 			}
1372 			printf("-> %" PRIu64 "\n", (uint64_t)p);
1373 			vmem_dump(vm);
1374 			if (p == VMEM_ADDR_NULL) {
1375 				if (x) {
1376 					continue;
1377 				}
1378 				break;
1379 			}
1380 			nreg++;
1381 			reg = realloc(reg, sizeof(*reg) * nreg);
1382 			r = &reg[nreg - 1];
1383 			r->p = p;
1384 			r->sz = sz;
1385 			r->x = x;
1386 			total += sz;
1387 			nalloc++;
1388 		} else if (nreg != 0) {
1389 			/* free */
1390 			r = &reg[rand() % nreg];
1391 			printf("=== free %" PRIu64 ", %" PRIu64 "\n",
1392 			    (uint64_t)r->p, (uint64_t)r->sz);
1393 			if (r->x) {
1394 				vmem_xfree(vm, r->p, r->sz);
1395 			} else {
1396 				vmem_free(vm, r->p, r->sz);
1397 			}
1398 			total -= r->sz;
1399 			vmem_dump(vm);
1400 			*r = reg[nreg - 1];
1401 			nreg--;
1402 			nfree++;
1403 		}
1404 		printf("total=%" PRIu64 "\n", (uint64_t)total);
1405 	}
1406 	fprintf(stderr, "total=%" PRIu64 ", nalloc=%d, nfree=%d\n",
1407 	    (uint64_t)total, nalloc, nfree);
1408 	exit(EXIT_SUCCESS);
1409 }
1410 #endif /* !defined(_KERNEL) */
1411 #endif /* defined(VMEM_DEBUG) */
1412