xref: /freebsd/sys/vm/uma_core.c (revision 74bf4e164ba5851606a27d4feff27717452583e5)
1 /*
2  * Copyright (c) 2002, Jeffrey Roberson <jeff@freebsd.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice unmodified, this list of conditions, and the following
10  *    disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 /*
28  * uma_core.c  Implementation of the Universal Memory allocator
29  *
30  * This allocator is intended to replace the multitude of similar object caches
31  * in the standard FreeBSD kernel.  The intent is to be flexible as well as
32  * effecient.  A primary design goal is to return unused memory to the rest of
33  * the system.  This will make the system as a whole more flexible due to the
34  * ability to move memory to subsystems which most need it instead of leaving
35  * pools of reserved memory unused.
36  *
37  * The basic ideas stem from similar slab/zone based allocators whose algorithms
38  * are well known.
39  *
40  */
41 
42 /*
43  * TODO:
44  *	- Improve memory usage for large allocations
45  *	- Investigate cache size adjustments
46  */
47 
48 #include <sys/cdefs.h>
49 __FBSDID("$FreeBSD$");
50 
51 /* I should really use ktr.. */
52 /*
53 #define UMA_DEBUG 1
54 #define UMA_DEBUG_ALLOC 1
55 #define UMA_DEBUG_ALLOC_1 1
56 */
57 
58 #include "opt_param.h"
59 #include <sys/param.h>
60 #include <sys/systm.h>
61 #include <sys/kernel.h>
62 #include <sys/types.h>
63 #include <sys/queue.h>
64 #include <sys/malloc.h>
65 #include <sys/ktr.h>
66 #include <sys/lock.h>
67 #include <sys/sysctl.h>
68 #include <sys/mutex.h>
69 #include <sys/proc.h>
70 #include <sys/smp.h>
71 #include <sys/vmmeter.h>
72 
73 #include <vm/vm.h>
74 #include <vm/vm_object.h>
75 #include <vm/vm_page.h>
76 #include <vm/vm_param.h>
77 #include <vm/vm_map.h>
78 #include <vm/vm_kern.h>
79 #include <vm/vm_extern.h>
80 #include <vm/uma.h>
81 #include <vm/uma_int.h>
82 #include <vm/uma_dbg.h>
83 
84 #include <machine/vmparam.h>
85 
86 /*
87  * This is the zone and keg from which all zones are spawned.  The idea is that
88  * even the zone & keg heads are allocated from the allocator, so we use the
89  * bss section to bootstrap us.
90  */
91 static struct uma_keg masterkeg;
92 static struct uma_zone masterzone_k;
93 static struct uma_zone masterzone_z;
94 static uma_zone_t kegs = &masterzone_k;
95 static uma_zone_t zones = &masterzone_z;
96 
97 /* This is the zone from which all of uma_slab_t's are allocated. */
98 static uma_zone_t slabzone;
99 static uma_zone_t slabrefzone;	/* With refcounters (for UMA_ZONE_REFCNT) */
100 
101 /*
102  * The initial hash tables come out of this zone so they can be allocated
103  * prior to malloc coming up.
104  */
105 static uma_zone_t hashzone;
106 
107 static MALLOC_DEFINE(M_UMAHASH, "UMAHash", "UMA Hash Buckets");
108 
109 /*
110  * Are we allowed to allocate buckets?
111  */
112 static int bucketdisable = 1;
113 
114 /* Linked list of all kegs in the system */
115 static LIST_HEAD(,uma_keg) uma_kegs = LIST_HEAD_INITIALIZER(&uma_kegs);
116 
117 /* This mutex protects the keg list */
118 static struct mtx uma_mtx;
119 
120 /* These are the pcpu cache locks */
121 static struct mtx uma_pcpu_mtx[MAXCPU];
122 
123 /* Linked list of boot time pages */
124 static LIST_HEAD(,uma_slab) uma_boot_pages =
125     LIST_HEAD_INITIALIZER(&uma_boot_pages);
126 
127 /* Count of free boottime pages */
128 static int uma_boot_free = 0;
129 
130 /* Is the VM done starting up? */
131 static int booted = 0;
132 
133 /* Maximum number of allowed items-per-slab if the slab header is OFFPAGE */
134 static u_int uma_max_ipers;
135 static u_int uma_max_ipers_ref;
136 
137 /*
138  * This is the handle used to schedule events that need to happen
139  * outside of the allocation fast path.
140  */
141 static struct callout uma_callout;
142 #define	UMA_TIMEOUT	20		/* Seconds for callout interval. */
143 
144 /*
145  * This structure is passed as the zone ctor arg so that I don't have to create
146  * a special allocation function just for zones.
147  */
148 struct uma_zctor_args {
149 	char *name;
150 	size_t size;
151 	uma_ctor ctor;
152 	uma_dtor dtor;
153 	uma_init uminit;
154 	uma_fini fini;
155 	uma_keg_t keg;
156 	int align;
157 	u_int16_t flags;
158 };
159 
160 struct uma_kctor_args {
161 	uma_zone_t zone;
162 	size_t size;
163 	uma_init uminit;
164 	uma_fini fini;
165 	int align;
166 	u_int16_t flags;
167 };
168 
169 struct uma_bucket_zone {
170 	uma_zone_t	ubz_zone;
171 	char		*ubz_name;
172 	int		ubz_entries;
173 };
174 
175 #define	BUCKET_MAX	128
176 
177 struct uma_bucket_zone bucket_zones[] = {
178 	{ NULL, "16 Bucket", 16 },
179 	{ NULL, "32 Bucket", 32 },
180 	{ NULL, "64 Bucket", 64 },
181 	{ NULL, "128 Bucket", 128 },
182 	{ NULL, NULL, 0}
183 };
184 
185 #define	BUCKET_SHIFT	4
186 #define	BUCKET_ZONES	((BUCKET_MAX >> BUCKET_SHIFT) + 1)
187 
188 uint8_t bucket_size[BUCKET_ZONES];
189 
190 enum zfreeskip { SKIP_NONE, SKIP_DTOR, SKIP_FINI };
191 
192 /* Prototypes.. */
193 
194 static void *obj_alloc(uma_zone_t, int, u_int8_t *, int);
195 static void *page_alloc(uma_zone_t, int, u_int8_t *, int);
196 static void *startup_alloc(uma_zone_t, int, u_int8_t *, int);
197 static void page_free(void *, int, u_int8_t);
198 static uma_slab_t slab_zalloc(uma_zone_t, int);
199 static void cache_drain(uma_zone_t);
200 static void bucket_drain(uma_zone_t, uma_bucket_t);
201 static void bucket_cache_drain(uma_zone_t zone);
202 static int keg_ctor(void *, int, void *, int);
203 static void keg_dtor(void *, int, void *);
204 static int zone_ctor(void *, int, void *, int);
205 static void zone_dtor(void *, int, void *);
206 static int zero_init(void *, int, int);
207 static void zone_small_init(uma_zone_t zone);
208 static void zone_large_init(uma_zone_t zone);
209 static void zone_foreach(void (*zfunc)(uma_zone_t));
210 static void zone_timeout(uma_zone_t zone);
211 static int hash_alloc(struct uma_hash *);
212 static int hash_expand(struct uma_hash *, struct uma_hash *);
213 static void hash_free(struct uma_hash *hash);
214 static void uma_timeout(void *);
215 static void uma_startup3(void);
216 static void *uma_zalloc_internal(uma_zone_t, void *, int);
217 static void uma_zfree_internal(uma_zone_t, void *, void *, enum zfreeskip);
218 static void bucket_enable(void);
219 static void bucket_init(void);
220 static uma_bucket_t bucket_alloc(int, int);
221 static void bucket_free(uma_bucket_t);
222 static void bucket_zone_drain(void);
223 static int uma_zalloc_bucket(uma_zone_t zone, int flags);
224 static uma_slab_t uma_zone_slab(uma_zone_t zone, int flags);
225 static void *uma_slab_alloc(uma_zone_t zone, uma_slab_t slab);
226 static void zone_drain(uma_zone_t);
227 static uma_zone_t uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit,
228     uma_fini fini, int align, u_int16_t flags);
229 
230 void uma_print_zone(uma_zone_t);
231 void uma_print_stats(void);
232 static int sysctl_vm_zone(SYSCTL_HANDLER_ARGS);
233 
234 #ifdef WITNESS
235 static int nosleepwithlocks = 1;
236 SYSCTL_INT(_debug, OID_AUTO, nosleepwithlocks, CTLFLAG_RW, &nosleepwithlocks,
237     0, "Convert M_WAITOK to M_NOWAIT to avoid lock-held-across-sleep paths");
238 #else
239 static int nosleepwithlocks = 0;
240 SYSCTL_INT(_debug, OID_AUTO, nosleepwithlocks, CTLFLAG_RW, &nosleepwithlocks,
241     0, "Convert M_WAITOK to M_NOWAIT to avoid lock-held-across-sleep paths");
242 #endif
243 SYSCTL_OID(_vm, OID_AUTO, zone, CTLTYPE_STRING|CTLFLAG_RD,
244     NULL, 0, sysctl_vm_zone, "A", "Zone Info");
245 SYSINIT(uma_startup3, SI_SUB_VM_CONF, SI_ORDER_SECOND, uma_startup3, NULL);
246 
247 /*
248  * This routine checks to see whether or not it's safe to enable buckets.
249  */
250 
251 static void
252 bucket_enable(void)
253 {
254 	if (cnt.v_free_count < cnt.v_free_min)
255 		bucketdisable = 1;
256 	else
257 		bucketdisable = 0;
258 }
259 
260 static void
261 bucket_init(void)
262 {
263 	struct uma_bucket_zone *ubz;
264 	int i;
265 	int j;
266 
267 	for (i = 0, j = 0; bucket_zones[j].ubz_entries != 0; j++) {
268 		int size;
269 
270 		ubz = &bucket_zones[j];
271 		size = roundup(sizeof(struct uma_bucket), sizeof(void *));
272 		size += sizeof(void *) * ubz->ubz_entries;
273 		ubz->ubz_zone = uma_zcreate(ubz->ubz_name, size,
274 		    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
275 		for (; i <= ubz->ubz_entries; i += (1 << BUCKET_SHIFT))
276 			bucket_size[i >> BUCKET_SHIFT] = j;
277 	}
278 }
279 
280 static uma_bucket_t
281 bucket_alloc(int entries, int bflags)
282 {
283 	struct uma_bucket_zone *ubz;
284 	uma_bucket_t bucket;
285 	int idx;
286 
287 	/*
288 	 * This is to stop us from allocating per cpu buckets while we're
289 	 * running out of UMA_BOOT_PAGES.  Otherwise, we would exhaust the
290 	 * boot pages.  This also prevents us from allocating buckets in
291 	 * low memory situations.
292 	 */
293 
294 	if (bucketdisable)
295 		return (NULL);
296 	idx = howmany(entries, 1 << BUCKET_SHIFT);
297 	ubz = &bucket_zones[bucket_size[idx]];
298 	bucket = uma_zalloc_internal(ubz->ubz_zone, NULL, bflags);
299 	if (bucket) {
300 #ifdef INVARIANTS
301 		bzero(bucket->ub_bucket, sizeof(void *) * ubz->ubz_entries);
302 #endif
303 		bucket->ub_cnt = 0;
304 		bucket->ub_entries = ubz->ubz_entries;
305 	}
306 
307 	return (bucket);
308 }
309 
310 static void
311 bucket_free(uma_bucket_t bucket)
312 {
313 	struct uma_bucket_zone *ubz;
314 	int idx;
315 
316 	idx = howmany(bucket->ub_entries, 1 << BUCKET_SHIFT);
317 	ubz = &bucket_zones[bucket_size[idx]];
318 	uma_zfree_internal(ubz->ubz_zone, bucket, NULL, SKIP_NONE);
319 }
320 
321 static void
322 bucket_zone_drain(void)
323 {
324 	struct uma_bucket_zone *ubz;
325 
326 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
327 		zone_drain(ubz->ubz_zone);
328 }
329 
330 
331 /*
332  * Routine called by timeout which is used to fire off some time interval
333  * based calculations.  (stats, hash size, etc.)
334  *
335  * Arguments:
336  *	arg   Unused
337  *
338  * Returns:
339  *	Nothing
340  */
341 static void
342 uma_timeout(void *unused)
343 {
344 	bucket_enable();
345 	zone_foreach(zone_timeout);
346 
347 	/* Reschedule this event */
348 	callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
349 }
350 
351 /*
352  * Routine to perform timeout driven calculations.  This expands the
353  * hashes and does per cpu statistics aggregation.
354  *
355  *  Arguments:
356  *	zone  The zone to operate on
357  *
358  *  Returns:
359  *	Nothing
360  */
361 static void
362 zone_timeout(uma_zone_t zone)
363 {
364 	uma_keg_t keg;
365 	uma_cache_t cache;
366 	u_int64_t alloc;
367 	int cpu;
368 
369 	keg = zone->uz_keg;
370 	alloc = 0;
371 
372 	/*
373 	 * Aggregate per cpu cache statistics back to the zone.
374 	 *
375 	 * XXX This should be done in the sysctl handler.
376 	 *
377 	 * I may rewrite this to set a flag in the per cpu cache instead of
378 	 * locking.  If the flag is not cleared on the next round I will have
379 	 * to lock and do it here instead so that the statistics don't get too
380 	 * far out of sync.
381 	 */
382 	if (!(keg->uk_flags & UMA_ZFLAG_INTERNAL)) {
383 		for (cpu = 0; cpu <= mp_maxid; cpu++) {
384 			if (CPU_ABSENT(cpu))
385 				continue;
386 			CPU_LOCK(cpu);
387 			cache = &zone->uz_cpu[cpu];
388 			/* Add them up, and reset */
389 			alloc += cache->uc_allocs;
390 			cache->uc_allocs = 0;
391 			CPU_UNLOCK(cpu);
392 		}
393 	}
394 
395 	/* Now push these stats back into the zone.. */
396 	ZONE_LOCK(zone);
397 	zone->uz_allocs += alloc;
398 
399 	/*
400 	 * Expand the zone hash table.
401 	 *
402 	 * This is done if the number of slabs is larger than the hash size.
403 	 * What I'm trying to do here is completely reduce collisions.  This
404 	 * may be a little aggressive.  Should I allow for two collisions max?
405 	 */
406 
407 	if (keg->uk_flags & UMA_ZONE_HASH &&
408 	    keg->uk_pages / keg->uk_ppera >= keg->uk_hash.uh_hashsize) {
409 		struct uma_hash newhash;
410 		struct uma_hash oldhash;
411 		int ret;
412 
413 		/*
414 		 * This is so involved because allocating and freeing
415 		 * while the zone lock is held will lead to deadlock.
416 		 * I have to do everything in stages and check for
417 		 * races.
418 		 */
419 		newhash = keg->uk_hash;
420 		ZONE_UNLOCK(zone);
421 		ret = hash_alloc(&newhash);
422 		ZONE_LOCK(zone);
423 		if (ret) {
424 			if (hash_expand(&keg->uk_hash, &newhash)) {
425 				oldhash = keg->uk_hash;
426 				keg->uk_hash = newhash;
427 			} else
428 				oldhash = newhash;
429 
430 			ZONE_UNLOCK(zone);
431 			hash_free(&oldhash);
432 			ZONE_LOCK(zone);
433 		}
434 	}
435 	ZONE_UNLOCK(zone);
436 }
437 
438 /*
439  * Allocate and zero fill the next sized hash table from the appropriate
440  * backing store.
441  *
442  * Arguments:
443  *	hash  A new hash structure with the old hash size in uh_hashsize
444  *
445  * Returns:
446  *	1 on sucess and 0 on failure.
447  */
448 static int
449 hash_alloc(struct uma_hash *hash)
450 {
451 	int oldsize;
452 	int alloc;
453 
454 	oldsize = hash->uh_hashsize;
455 
456 	/* We're just going to go to a power of two greater */
457 	if (oldsize)  {
458 		hash->uh_hashsize = oldsize * 2;
459 		alloc = sizeof(hash->uh_slab_hash[0]) * hash->uh_hashsize;
460 		hash->uh_slab_hash = (struct slabhead *)malloc(alloc,
461 		    M_UMAHASH, M_NOWAIT);
462 	} else {
463 		alloc = sizeof(hash->uh_slab_hash[0]) * UMA_HASH_SIZE_INIT;
464 		hash->uh_slab_hash = uma_zalloc_internal(hashzone, NULL,
465 		    M_WAITOK);
466 		hash->uh_hashsize = UMA_HASH_SIZE_INIT;
467 	}
468 	if (hash->uh_slab_hash) {
469 		bzero(hash->uh_slab_hash, alloc);
470 		hash->uh_hashmask = hash->uh_hashsize - 1;
471 		return (1);
472 	}
473 
474 	return (0);
475 }
476 
477 /*
478  * Expands the hash table for HASH zones.  This is done from zone_timeout
479  * to reduce collisions.  This must not be done in the regular allocation
480  * path, otherwise, we can recurse on the vm while allocating pages.
481  *
482  * Arguments:
483  *	oldhash  The hash you want to expand
484  *	newhash  The hash structure for the new table
485  *
486  * Returns:
487  *	Nothing
488  *
489  * Discussion:
490  */
491 static int
492 hash_expand(struct uma_hash *oldhash, struct uma_hash *newhash)
493 {
494 	uma_slab_t slab;
495 	int hval;
496 	int i;
497 
498 	if (!newhash->uh_slab_hash)
499 		return (0);
500 
501 	if (oldhash->uh_hashsize >= newhash->uh_hashsize)
502 		return (0);
503 
504 	/*
505 	 * I need to investigate hash algorithms for resizing without a
506 	 * full rehash.
507 	 */
508 
509 	for (i = 0; i < oldhash->uh_hashsize; i++)
510 		while (!SLIST_EMPTY(&oldhash->uh_slab_hash[i])) {
511 			slab = SLIST_FIRST(&oldhash->uh_slab_hash[i]);
512 			SLIST_REMOVE_HEAD(&oldhash->uh_slab_hash[i], us_hlink);
513 			hval = UMA_HASH(newhash, slab->us_data);
514 			SLIST_INSERT_HEAD(&newhash->uh_slab_hash[hval],
515 			    slab, us_hlink);
516 		}
517 
518 	return (1);
519 }
520 
521 /*
522  * Free the hash bucket to the appropriate backing store.
523  *
524  * Arguments:
525  *	slab_hash  The hash bucket we're freeing
526  *	hashsize   The number of entries in that hash bucket
527  *
528  * Returns:
529  *	Nothing
530  */
531 static void
532 hash_free(struct uma_hash *hash)
533 {
534 	if (hash->uh_slab_hash == NULL)
535 		return;
536 	if (hash->uh_hashsize == UMA_HASH_SIZE_INIT)
537 		uma_zfree_internal(hashzone,
538 		    hash->uh_slab_hash, NULL, SKIP_NONE);
539 	else
540 		free(hash->uh_slab_hash, M_UMAHASH);
541 }
542 
543 /*
544  * Frees all outstanding items in a bucket
545  *
546  * Arguments:
547  *	zone   The zone to free to, must be unlocked.
548  *	bucket The free/alloc bucket with items, cpu queue must be locked.
549  *
550  * Returns:
551  *	Nothing
552  */
553 
554 static void
555 bucket_drain(uma_zone_t zone, uma_bucket_t bucket)
556 {
557 	uma_slab_t slab;
558 	int mzone;
559 	void *item;
560 
561 	if (bucket == NULL)
562 		return;
563 
564 	slab = NULL;
565 	mzone = 0;
566 
567 	/* We have to lookup the slab again for malloc.. */
568 	if (zone->uz_keg->uk_flags & UMA_ZONE_MALLOC)
569 		mzone = 1;
570 
571 	while (bucket->ub_cnt > 0)  {
572 		bucket->ub_cnt--;
573 		item = bucket->ub_bucket[bucket->ub_cnt];
574 #ifdef INVARIANTS
575 		bucket->ub_bucket[bucket->ub_cnt] = NULL;
576 		KASSERT(item != NULL,
577 		    ("bucket_drain: botched ptr, item is NULL"));
578 #endif
579 		/*
580 		 * This is extremely inefficient.  The slab pointer was passed
581 		 * to uma_zfree_arg, but we lost it because the buckets don't
582 		 * hold them.  This will go away when free() gets a size passed
583 		 * to it.
584 		 */
585 		if (mzone)
586 			slab = vtoslab((vm_offset_t)item & (~UMA_SLAB_MASK));
587 		uma_zfree_internal(zone, item, slab, SKIP_DTOR);
588 	}
589 }
590 
591 /*
592  * Drains the per cpu caches for a zone.
593  *
594  * Arguments:
595  *	zone     The zone to drain, must be unlocked.
596  *
597  * Returns:
598  *	Nothing
599  */
600 static void
601 cache_drain(uma_zone_t zone)
602 {
603 	uma_cache_t cache;
604 	int cpu;
605 
606 	/*
607 	 * We have to lock each cpu cache before locking the zone
608 	 */
609 	for (cpu = 0; cpu <= mp_maxid; cpu++) {
610 		if (CPU_ABSENT(cpu))
611 			continue;
612 		CPU_LOCK(cpu);
613 		cache = &zone->uz_cpu[cpu];
614 		bucket_drain(zone, cache->uc_allocbucket);
615 		bucket_drain(zone, cache->uc_freebucket);
616 		if (cache->uc_allocbucket != NULL)
617 			bucket_free(cache->uc_allocbucket);
618 		if (cache->uc_freebucket != NULL)
619 			bucket_free(cache->uc_freebucket);
620 		cache->uc_allocbucket = cache->uc_freebucket = NULL;
621 	}
622 	ZONE_LOCK(zone);
623 	bucket_cache_drain(zone);
624 	ZONE_UNLOCK(zone);
625 	for (cpu = 0; cpu <= mp_maxid; cpu++) {
626 		if (CPU_ABSENT(cpu))
627 			continue;
628 		CPU_UNLOCK(cpu);
629 	}
630 }
631 
632 /*
633  * Drain the cached buckets from a zone.  Expects a locked zone on entry.
634  */
635 static void
636 bucket_cache_drain(uma_zone_t zone)
637 {
638 	uma_bucket_t bucket;
639 
640 	/*
641 	 * Drain the bucket queues and free the buckets, we just keep two per
642 	 * cpu (alloc/free).
643 	 */
644 	while ((bucket = LIST_FIRST(&zone->uz_full_bucket)) != NULL) {
645 		LIST_REMOVE(bucket, ub_link);
646 		ZONE_UNLOCK(zone);
647 		bucket_drain(zone, bucket);
648 		bucket_free(bucket);
649 		ZONE_LOCK(zone);
650 	}
651 
652 	/* Now we do the free queue.. */
653 	while ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) {
654 		LIST_REMOVE(bucket, ub_link);
655 		bucket_free(bucket);
656 	}
657 }
658 
659 /*
660  * Frees pages from a zone back to the system.  This is done on demand from
661  * the pageout daemon.
662  *
663  * Arguments:
664  *	zone  The zone to free pages from
665  *	 all  Should we drain all items?
666  *
667  * Returns:
668  *	Nothing.
669  */
670 static void
671 zone_drain(uma_zone_t zone)
672 {
673 	struct slabhead freeslabs = {};
674 	uma_keg_t keg;
675 	uma_slab_t slab;
676 	uma_slab_t n;
677 	u_int8_t flags;
678 	u_int8_t *mem;
679 	int i;
680 
681 	keg = zone->uz_keg;
682 
683 	/*
684 	 * We don't want to take pages from statically allocated zones at this
685 	 * time
686 	 */
687 	if (keg->uk_flags & UMA_ZONE_NOFREE || keg->uk_freef == NULL)
688 		return;
689 
690 	ZONE_LOCK(zone);
691 
692 #ifdef UMA_DEBUG
693 	printf("%s free items: %u\n", zone->uz_name, keg->uk_free);
694 #endif
695 	bucket_cache_drain(zone);
696 	if (keg->uk_free == 0)
697 		goto finished;
698 
699 	slab = LIST_FIRST(&keg->uk_free_slab);
700 	while (slab) {
701 		n = LIST_NEXT(slab, us_link);
702 
703 		/* We have no where to free these to */
704 		if (slab->us_flags & UMA_SLAB_BOOT) {
705 			slab = n;
706 			continue;
707 		}
708 
709 		LIST_REMOVE(slab, us_link);
710 		keg->uk_pages -= keg->uk_ppera;
711 		keg->uk_free -= keg->uk_ipers;
712 
713 		if (keg->uk_flags & UMA_ZONE_HASH)
714 			UMA_HASH_REMOVE(&keg->uk_hash, slab, slab->us_data);
715 
716 		SLIST_INSERT_HEAD(&freeslabs, slab, us_hlink);
717 
718 		slab = n;
719 	}
720 finished:
721 	ZONE_UNLOCK(zone);
722 
723 	while ((slab = SLIST_FIRST(&freeslabs)) != NULL) {
724 		SLIST_REMOVE(&freeslabs, slab, uma_slab, us_hlink);
725 		if (keg->uk_fini)
726 			for (i = 0; i < keg->uk_ipers; i++)
727 				keg->uk_fini(
728 				    slab->us_data + (keg->uk_rsize * i),
729 				    keg->uk_size);
730 		flags = slab->us_flags;
731 		mem = slab->us_data;
732 
733 		if ((keg->uk_flags & UMA_ZONE_MALLOC) ||
734 		    (keg->uk_flags & UMA_ZONE_REFCNT)) {
735 			vm_object_t obj;
736 
737 			if (flags & UMA_SLAB_KMEM)
738 				obj = kmem_object;
739 			else
740 				obj = NULL;
741 			for (i = 0; i < keg->uk_ppera; i++)
742 				vsetobj((vm_offset_t)mem + (i * PAGE_SIZE),
743 				    obj);
744 		}
745 		if (keg->uk_flags & UMA_ZONE_OFFPAGE)
746 			uma_zfree_internal(keg->uk_slabzone, slab, NULL,
747 			    SKIP_NONE);
748 #ifdef UMA_DEBUG
749 		printf("%s: Returning %d bytes.\n",
750 		    zone->uz_name, UMA_SLAB_SIZE * keg->uk_ppera);
751 #endif
752 		keg->uk_freef(mem, UMA_SLAB_SIZE * keg->uk_ppera, flags);
753 	}
754 }
755 
756 /*
757  * Allocate a new slab for a zone.  This does not insert the slab onto a list.
758  *
759  * Arguments:
760  *	zone  The zone to allocate slabs for
761  *	wait  Shall we wait?
762  *
763  * Returns:
764  *	The slab that was allocated or NULL if there is no memory and the
765  *	caller specified M_NOWAIT.
766  */
767 static uma_slab_t
768 slab_zalloc(uma_zone_t zone, int wait)
769 {
770 	uma_slabrefcnt_t slabref;
771 	uma_slab_t slab;
772 	uma_keg_t keg;
773 	u_int8_t *mem;
774 	u_int8_t flags;
775 	int i;
776 
777 	slab = NULL;
778 	keg = zone->uz_keg;
779 
780 #ifdef UMA_DEBUG
781 	printf("slab_zalloc:  Allocating a new slab for %s\n", zone->uz_name);
782 #endif
783 	ZONE_UNLOCK(zone);
784 
785 	if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
786 		slab = uma_zalloc_internal(keg->uk_slabzone, NULL, wait);
787 		if (slab == NULL) {
788 			ZONE_LOCK(zone);
789 			return NULL;
790 		}
791 	}
792 
793 	/*
794 	 * This reproduces the old vm_zone behavior of zero filling pages the
795 	 * first time they are added to a zone.
796 	 *
797 	 * Malloced items are zeroed in uma_zalloc.
798 	 */
799 
800 	if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
801 		wait |= M_ZERO;
802 	else
803 		wait &= ~M_ZERO;
804 
805 	mem = keg->uk_allocf(zone, keg->uk_ppera * UMA_SLAB_SIZE,
806 	    &flags, wait);
807 	if (mem == NULL) {
808 		if (keg->uk_flags & UMA_ZONE_OFFPAGE)
809 			uma_zfree_internal(keg->uk_slabzone, slab, NULL, 0);
810 		ZONE_LOCK(zone);
811 		return (NULL);
812 	}
813 
814 	/* Point the slab into the allocated memory */
815 	if (!(keg->uk_flags & UMA_ZONE_OFFPAGE))
816 		slab = (uma_slab_t )(mem + keg->uk_pgoff);
817 
818 	if ((keg->uk_flags & UMA_ZONE_MALLOC) ||
819 	    (keg->uk_flags & UMA_ZONE_REFCNT))
820 		for (i = 0; i < keg->uk_ppera; i++)
821 			vsetslab((vm_offset_t)mem + (i * PAGE_SIZE), slab);
822 
823 	slab->us_keg = keg;
824 	slab->us_data = mem;
825 	slab->us_freecount = keg->uk_ipers;
826 	slab->us_firstfree = 0;
827 	slab->us_flags = flags;
828 	for (i = 0; i < keg->uk_ipers; i++)
829 		slab->us_freelist[i].us_item = i+1;
830 
831 	if (keg->uk_flags & UMA_ZONE_REFCNT) {
832 		slabref = (uma_slabrefcnt_t)slab;
833 		for (i = 0; i < keg->uk_ipers; i++)
834 			slabref->us_freelist[i].us_refcnt = 0;
835 	}
836 
837 	if (keg->uk_init != NULL) {
838 		for (i = 0; i < keg->uk_ipers; i++)
839 			if (keg->uk_init(slab->us_data + (keg->uk_rsize * i),
840 			    keg->uk_size, wait) != 0)
841 				break;
842 		if (i != keg->uk_ipers) {
843 			if (keg->uk_fini != NULL) {
844 				for (i--; i > -1; i--)
845 					keg->uk_fini(slab->us_data +
846 					    (keg->uk_rsize * i),
847 					    keg->uk_size);
848 			}
849 			if ((keg->uk_flags & UMA_ZONE_MALLOC) ||
850 			    (keg->uk_flags & UMA_ZONE_REFCNT))
851 				for (i = 0; i < keg->uk_ppera; i++)
852 					vsetobj((vm_offset_t)mem +
853 					    (i * PAGE_SIZE), NULL);
854 			if (keg->uk_flags & UMA_ZONE_OFFPAGE)
855 				uma_zfree_internal(keg->uk_slabzone, slab,
856 				    NULL, SKIP_NONE);
857 			keg->uk_freef(mem, UMA_SLAB_SIZE * keg->uk_ppera,
858 			    flags);
859 			ZONE_LOCK(zone);
860 			return (NULL);
861 		}
862 	}
863 	ZONE_LOCK(zone);
864 
865 	if (keg->uk_flags & UMA_ZONE_HASH)
866 		UMA_HASH_INSERT(&keg->uk_hash, slab, mem);
867 
868 	keg->uk_pages += keg->uk_ppera;
869 	keg->uk_free += keg->uk_ipers;
870 
871 	return (slab);
872 }
873 
874 /*
875  * This function is intended to be used early on in place of page_alloc() so
876  * that we may use the boot time page cache to satisfy allocations before
877  * the VM is ready.
878  */
879 static void *
880 startup_alloc(uma_zone_t zone, int bytes, u_int8_t *pflag, int wait)
881 {
882 	uma_keg_t keg;
883 
884 	keg = zone->uz_keg;
885 
886 	/*
887 	 * Check our small startup cache to see if it has pages remaining.
888 	 */
889 	mtx_lock(&uma_mtx);
890 	if (uma_boot_free != 0) {
891 		uma_slab_t tmps;
892 
893 		tmps = LIST_FIRST(&uma_boot_pages);
894 		LIST_REMOVE(tmps, us_link);
895 		uma_boot_free--;
896 		mtx_unlock(&uma_mtx);
897 		*pflag = tmps->us_flags;
898 		return (tmps->us_data);
899 	}
900 	mtx_unlock(&uma_mtx);
901 	if (booted == 0)
902 		panic("UMA: Increase UMA_BOOT_PAGES");
903 	/*
904 	 * Now that we've booted reset these users to their real allocator.
905 	 */
906 #ifdef UMA_MD_SMALL_ALLOC
907 	keg->uk_allocf = uma_small_alloc;
908 #else
909 	keg->uk_allocf = page_alloc;
910 #endif
911 	return keg->uk_allocf(zone, bytes, pflag, wait);
912 }
913 
914 /*
915  * Allocates a number of pages from the system
916  *
917  * Arguments:
918  *	zone  Unused
919  *	bytes  The number of bytes requested
920  *	wait  Shall we wait?
921  *
922  * Returns:
923  *	A pointer to the alloced memory or possibly
924  *	NULL if M_NOWAIT is set.
925  */
926 static void *
927 page_alloc(uma_zone_t zone, int bytes, u_int8_t *pflag, int wait)
928 {
929 	void *p;	/* Returned page */
930 
931 	*pflag = UMA_SLAB_KMEM;
932 	p = (void *) kmem_malloc(kmem_map, bytes, wait);
933 
934 	return (p);
935 }
936 
937 /*
938  * Allocates a number of pages from within an object
939  *
940  * Arguments:
941  *	zone   Unused
942  *	bytes  The number of bytes requested
943  *	wait   Shall we wait?
944  *
945  * Returns:
946  *	A pointer to the alloced memory or possibly
947  *	NULL if M_NOWAIT is set.
948  */
949 static void *
950 obj_alloc(uma_zone_t zone, int bytes, u_int8_t *flags, int wait)
951 {
952 	vm_object_t object;
953 	vm_offset_t retkva, zkva;
954 	vm_page_t p;
955 	int pages, startpages;
956 
957 	object = zone->uz_keg->uk_obj;
958 	retkva = 0;
959 
960 	/*
961 	 * This looks a little weird since we're getting one page at a time.
962 	 */
963 	VM_OBJECT_LOCK(object);
964 	p = TAILQ_LAST(&object->memq, pglist);
965 	pages = p != NULL ? p->pindex + 1 : 0;
966 	startpages = pages;
967 	zkva = zone->uz_keg->uk_kva + pages * PAGE_SIZE;
968 	for (; bytes > 0; bytes -= PAGE_SIZE) {
969 		p = vm_page_alloc(object, pages,
970 		    VM_ALLOC_INTERRUPT | VM_ALLOC_WIRED);
971 		if (p == NULL) {
972 			if (pages != startpages)
973 				pmap_qremove(retkva, pages - startpages);
974 			while (pages != startpages) {
975 				pages--;
976 				p = TAILQ_LAST(&object->memq, pglist);
977 				vm_page_lock_queues();
978 				vm_page_unwire(p, 0);
979 				vm_page_free(p);
980 				vm_page_unlock_queues();
981 			}
982 			retkva = 0;
983 			goto done;
984 		}
985 		pmap_qenter(zkva, &p, 1);
986 		if (retkva == 0)
987 			retkva = zkva;
988 		zkva += PAGE_SIZE;
989 		pages += 1;
990 	}
991 done:
992 	VM_OBJECT_UNLOCK(object);
993 	*flags = UMA_SLAB_PRIV;
994 
995 	return ((void *)retkva);
996 }
997 
998 /*
999  * Frees a number of pages to the system
1000  *
1001  * Arguments:
1002  *	mem   A pointer to the memory to be freed
1003  *	size  The size of the memory being freed
1004  *	flags The original p->us_flags field
1005  *
1006  * Returns:
1007  *	Nothing
1008  */
1009 static void
1010 page_free(void *mem, int size, u_int8_t flags)
1011 {
1012 	vm_map_t map;
1013 
1014 	if (flags & UMA_SLAB_KMEM)
1015 		map = kmem_map;
1016 	else
1017 		panic("UMA: page_free used with invalid flags %d\n", flags);
1018 
1019 	kmem_free(map, (vm_offset_t)mem, size);
1020 }
1021 
1022 /*
1023  * Zero fill initializer
1024  *
1025  * Arguments/Returns follow uma_init specifications
1026  */
1027 static int
1028 zero_init(void *mem, int size, int flags)
1029 {
1030 	bzero(mem, size);
1031 	return (0);
1032 }
1033 
1034 /*
1035  * Finish creating a small uma zone.  This calculates ipers, and the zone size.
1036  *
1037  * Arguments
1038  *	zone  The zone we should initialize
1039  *
1040  * Returns
1041  *	Nothing
1042  */
1043 static void
1044 zone_small_init(uma_zone_t zone)
1045 {
1046 	uma_keg_t keg;
1047 	u_int rsize;
1048 	u_int memused;
1049 	u_int wastedspace;
1050 	u_int shsize;
1051 
1052 	keg = zone->uz_keg;
1053 	KASSERT(keg != NULL, ("Keg is null in zone_small_init"));
1054 	rsize = keg->uk_size;
1055 
1056 	if (rsize < UMA_SMALLEST_UNIT)
1057 		rsize = UMA_SMALLEST_UNIT;
1058 	if (rsize & keg->uk_align)
1059 		rsize = (rsize & ~keg->uk_align) + (keg->uk_align + 1);
1060 
1061 	keg->uk_rsize = rsize;
1062 	keg->uk_ppera = 1;
1063 
1064 	if (keg->uk_flags & UMA_ZONE_REFCNT) {
1065 		rsize += UMA_FRITMREF_SZ;	/* linkage & refcnt */
1066 		shsize = sizeof(struct uma_slab_refcnt);
1067 	} else {
1068 		rsize += UMA_FRITM_SZ;	/* Account for linkage */
1069 		shsize = sizeof(struct uma_slab);
1070 	}
1071 
1072 	keg->uk_ipers = (UMA_SLAB_SIZE - shsize) / rsize;
1073 	KASSERT(keg->uk_ipers != 0, ("zone_small_init: ipers is 0"));
1074 	memused = keg->uk_ipers * rsize + shsize;
1075 	wastedspace = UMA_SLAB_SIZE - memused;
1076 
1077 	/*
1078 	 * We can't do OFFPAGE if we're internal or if we've been
1079 	 * asked to not go to the VM for buckets.  If we do this we
1080 	 * may end up going to the VM (kmem_map) for slabs which we
1081 	 * do not want to do if we're UMA_ZFLAG_CACHEONLY as a
1082 	 * result of UMA_ZONE_VM, which clearly forbids it.
1083 	 */
1084 	if ((keg->uk_flags & UMA_ZFLAG_INTERNAL) ||
1085 	    (keg->uk_flags & UMA_ZFLAG_CACHEONLY))
1086 		return;
1087 
1088 	if ((wastedspace >= UMA_MAX_WASTE) &&
1089 	    (keg->uk_ipers < (UMA_SLAB_SIZE / keg->uk_rsize))) {
1090 		keg->uk_ipers = UMA_SLAB_SIZE / keg->uk_rsize;
1091 		KASSERT(keg->uk_ipers <= 255,
1092 		    ("zone_small_init: keg->uk_ipers too high!"));
1093 #ifdef UMA_DEBUG
1094 		printf("UMA decided we need offpage slab headers for "
1095 		    "zone: %s, calculated wastedspace = %d, "
1096 		    "maximum wasted space allowed = %d, "
1097 		    "calculated ipers = %d, "
1098 		    "new wasted space = %d\n", zone->uz_name, wastedspace,
1099 		    UMA_MAX_WASTE, keg->uk_ipers,
1100 		    UMA_SLAB_SIZE - keg->uk_ipers * keg->uk_rsize);
1101 #endif
1102 		keg->uk_flags |= UMA_ZONE_OFFPAGE;
1103 		if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
1104 			keg->uk_flags |= UMA_ZONE_HASH;
1105 	}
1106 }
1107 
1108 /*
1109  * Finish creating a large (> UMA_SLAB_SIZE) uma zone.  Just give in and do
1110  * OFFPAGE for now.  When I can allow for more dynamic slab sizes this will be
1111  * more complicated.
1112  *
1113  * Arguments
1114  *	zone  The zone we should initialize
1115  *
1116  * Returns
1117  *	Nothing
1118  */
1119 static void
1120 zone_large_init(uma_zone_t zone)
1121 {
1122 	uma_keg_t keg;
1123 	int pages;
1124 
1125 	keg = zone->uz_keg;
1126 
1127 	KASSERT(keg != NULL, ("Keg is null in zone_large_init"));
1128 	KASSERT((keg->uk_flags & UMA_ZFLAG_CACHEONLY) == 0,
1129 	    ("zone_large_init: Cannot large-init a UMA_ZFLAG_CACHEONLY zone"));
1130 
1131 	pages = keg->uk_size / UMA_SLAB_SIZE;
1132 
1133 	/* Account for remainder */
1134 	if ((pages * UMA_SLAB_SIZE) < keg->uk_size)
1135 		pages++;
1136 
1137 	keg->uk_ppera = pages;
1138 	keg->uk_ipers = 1;
1139 
1140 	keg->uk_flags |= UMA_ZONE_OFFPAGE;
1141 	if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
1142 		keg->uk_flags |= UMA_ZONE_HASH;
1143 
1144 	keg->uk_rsize = keg->uk_size;
1145 }
1146 
1147 /*
1148  * Keg header ctor.  This initializes all fields, locks, etc.  And inserts
1149  * the keg onto the global keg list.
1150  *
1151  * Arguments/Returns follow uma_ctor specifications
1152  *	udata  Actually uma_kctor_args
1153  */
1154 static int
1155 keg_ctor(void *mem, int size, void *udata, int flags)
1156 {
1157 	struct uma_kctor_args *arg = udata;
1158 	uma_keg_t keg = mem;
1159 	uma_zone_t zone;
1160 
1161 	bzero(keg, size);
1162 	keg->uk_size = arg->size;
1163 	keg->uk_init = arg->uminit;
1164 	keg->uk_fini = arg->fini;
1165 	keg->uk_align = arg->align;
1166 	keg->uk_free = 0;
1167 	keg->uk_pages = 0;
1168 	keg->uk_flags = arg->flags;
1169 	keg->uk_allocf = page_alloc;
1170 	keg->uk_freef = page_free;
1171 	keg->uk_recurse = 0;
1172 	keg->uk_slabzone = NULL;
1173 
1174 	/*
1175 	 * The master zone is passed to us at keg-creation time.
1176 	 */
1177 	zone = arg->zone;
1178 	zone->uz_keg = keg;
1179 
1180 	if (arg->flags & UMA_ZONE_VM)
1181 		keg->uk_flags |= UMA_ZFLAG_CACHEONLY;
1182 
1183 	if (arg->flags & UMA_ZONE_ZINIT)
1184 		keg->uk_init = zero_init;
1185 
1186 	/*
1187 	 * The +UMA_FRITM_SZ added to uk_size is to account for the
1188 	 * linkage that is added to the size in zone_small_init().  If
1189 	 * we don't account for this here then we may end up in
1190 	 * zone_small_init() with a calculated 'ipers' of 0.
1191 	 */
1192 	if (keg->uk_flags & UMA_ZONE_REFCNT) {
1193 		if ((keg->uk_size+UMA_FRITMREF_SZ) >
1194 		    (UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt)))
1195 			zone_large_init(zone);
1196 		else
1197 			zone_small_init(zone);
1198 	} else {
1199 		if ((keg->uk_size+UMA_FRITM_SZ) >
1200 		    (UMA_SLAB_SIZE - sizeof(struct uma_slab)))
1201 			zone_large_init(zone);
1202 		else
1203 			zone_small_init(zone);
1204 	}
1205 
1206 	if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
1207 		if (keg->uk_flags & UMA_ZONE_REFCNT)
1208 			keg->uk_slabzone = slabrefzone;
1209 		else
1210 			keg->uk_slabzone = slabzone;
1211 	}
1212 
1213 	/*
1214 	 * If we haven't booted yet we need allocations to go through the
1215 	 * startup cache until the vm is ready.
1216 	 */
1217 	if (keg->uk_ppera == 1) {
1218 #ifdef UMA_MD_SMALL_ALLOC
1219 		keg->uk_allocf = uma_small_alloc;
1220 		keg->uk_freef = uma_small_free;
1221 #endif
1222 		if (booted == 0)
1223 			keg->uk_allocf = startup_alloc;
1224 	}
1225 
1226 	/*
1227 	 * Initialize keg's lock (shared among zones) through
1228 	 * Master zone
1229 	 */
1230 	zone->uz_lock = &keg->uk_lock;
1231 	if (arg->flags & UMA_ZONE_MTXCLASS)
1232 		ZONE_LOCK_INIT(zone, 1);
1233 	else
1234 		ZONE_LOCK_INIT(zone, 0);
1235 
1236 	/*
1237 	 * If we're putting the slab header in the actual page we need to
1238 	 * figure out where in each page it goes.  This calculates a right
1239 	 * justified offset into the memory on an ALIGN_PTR boundary.
1240 	 */
1241 	if (!(keg->uk_flags & UMA_ZONE_OFFPAGE)) {
1242 		u_int totsize;
1243 
1244 		/* Size of the slab struct and free list */
1245 		if (keg->uk_flags & UMA_ZONE_REFCNT)
1246 			totsize = sizeof(struct uma_slab_refcnt) +
1247 			    keg->uk_ipers * UMA_FRITMREF_SZ;
1248 		else
1249 			totsize = sizeof(struct uma_slab) +
1250 			    keg->uk_ipers * UMA_FRITM_SZ;
1251 
1252 		if (totsize & UMA_ALIGN_PTR)
1253 			totsize = (totsize & ~UMA_ALIGN_PTR) +
1254 			    (UMA_ALIGN_PTR + 1);
1255 		keg->uk_pgoff = UMA_SLAB_SIZE - totsize;
1256 
1257 		if (keg->uk_flags & UMA_ZONE_REFCNT)
1258 			totsize = keg->uk_pgoff + sizeof(struct uma_slab_refcnt)
1259 			    + keg->uk_ipers * UMA_FRITMREF_SZ;
1260 		else
1261 			totsize = keg->uk_pgoff + sizeof(struct uma_slab)
1262 			    + keg->uk_ipers * UMA_FRITM_SZ;
1263 
1264 		/*
1265 		 * The only way the following is possible is if with our
1266 		 * UMA_ALIGN_PTR adjustments we are now bigger than
1267 		 * UMA_SLAB_SIZE.  I haven't checked whether this is
1268 		 * mathematically possible for all cases, so we make
1269 		 * sure here anyway.
1270 		 */
1271 		if (totsize > UMA_SLAB_SIZE) {
1272 			printf("zone %s ipers %d rsize %d size %d\n",
1273 			    zone->uz_name, keg->uk_ipers, keg->uk_rsize,
1274 			    keg->uk_size);
1275 			panic("UMA slab won't fit.\n");
1276 		}
1277 	}
1278 
1279 	if (keg->uk_flags & UMA_ZONE_HASH)
1280 		hash_alloc(&keg->uk_hash);
1281 
1282 #ifdef UMA_DEBUG
1283 	printf("%s(%p) size = %d ipers = %d ppera = %d pgoff = %d\n",
1284 	    zone->uz_name, zone,
1285 	    keg->uk_size, keg->uk_ipers,
1286 	    keg->uk_ppera, keg->uk_pgoff);
1287 #endif
1288 
1289 	LIST_INSERT_HEAD(&keg->uk_zones, zone, uz_link);
1290 
1291 	mtx_lock(&uma_mtx);
1292 	LIST_INSERT_HEAD(&uma_kegs, keg, uk_link);
1293 	mtx_unlock(&uma_mtx);
1294 	return (0);
1295 }
1296 
1297 /*
1298  * Zone header ctor.  This initializes all fields, locks, etc.
1299  *
1300  * Arguments/Returns follow uma_ctor specifications
1301  *	udata  Actually uma_zctor_args
1302  */
1303 
1304 static int
1305 zone_ctor(void *mem, int size, void *udata, int flags)
1306 {
1307 	struct uma_zctor_args *arg = udata;
1308 	uma_zone_t zone = mem;
1309 	uma_zone_t z;
1310 	uma_keg_t keg;
1311 
1312 	bzero(zone, size);
1313 	zone->uz_name = arg->name;
1314 	zone->uz_ctor = arg->ctor;
1315 	zone->uz_dtor = arg->dtor;
1316 	zone->uz_init = NULL;
1317 	zone->uz_fini = NULL;
1318 	zone->uz_allocs = 0;
1319 	zone->uz_fills = zone->uz_count = 0;
1320 
1321 	if (arg->flags & UMA_ZONE_SECONDARY) {
1322 		KASSERT(arg->keg != NULL, ("Secondary zone on zero'd keg"));
1323 		keg = arg->keg;
1324 		zone->uz_keg = keg;
1325 		zone->uz_init = arg->uminit;
1326 		zone->uz_fini = arg->fini;
1327 		zone->uz_lock = &keg->uk_lock;
1328 		mtx_lock(&uma_mtx);
1329 		ZONE_LOCK(zone);
1330 		keg->uk_flags |= UMA_ZONE_SECONDARY;
1331 		LIST_FOREACH(z, &keg->uk_zones, uz_link) {
1332 			if (LIST_NEXT(z, uz_link) == NULL) {
1333 				LIST_INSERT_AFTER(z, zone, uz_link);
1334 				break;
1335 			}
1336 		}
1337 		ZONE_UNLOCK(zone);
1338 		mtx_unlock(&uma_mtx);
1339 	} else if (arg->keg == NULL) {
1340 		if (uma_kcreate(zone, arg->size, arg->uminit, arg->fini,
1341 		    arg->align, arg->flags) == NULL)
1342 			return (ENOMEM);
1343 	} else {
1344 		struct uma_kctor_args karg;
1345 		int error;
1346 
1347 		/* We should only be here from uma_startup() */
1348 		karg.size = arg->size;
1349 		karg.uminit = arg->uminit;
1350 		karg.fini = arg->fini;
1351 		karg.align = arg->align;
1352 		karg.flags = arg->flags;
1353 		karg.zone = zone;
1354 		error = keg_ctor(arg->keg, sizeof(struct uma_keg), &karg,
1355 		    flags);
1356 		if (error)
1357 			return (error);
1358 	}
1359 	keg = zone->uz_keg;
1360 	zone->uz_lock = &keg->uk_lock;
1361 
1362 	/*
1363 	 * Some internal zones don't have room allocated for the per cpu
1364 	 * caches.  If we're internal, bail out here.
1365 	 */
1366 	if (keg->uk_flags & UMA_ZFLAG_INTERNAL) {
1367 		KASSERT((keg->uk_flags & UMA_ZONE_SECONDARY) == 0,
1368 		    ("Secondary zone requested UMA_ZFLAG_INTERNAL"));
1369 		return (0);
1370 	}
1371 
1372 	if (keg->uk_flags & UMA_ZONE_MAXBUCKET)
1373 		zone->uz_count = BUCKET_MAX;
1374 	else if (keg->uk_ipers <= BUCKET_MAX)
1375 		zone->uz_count = keg->uk_ipers;
1376 	else
1377 		zone->uz_count = BUCKET_MAX;
1378 	return (0);
1379 }
1380 
1381 /*
1382  * Keg header dtor.  This frees all data, destroys locks, frees the hash
1383  * table and removes the keg from the global list.
1384  *
1385  * Arguments/Returns follow uma_dtor specifications
1386  *	udata  unused
1387  */
1388 static void
1389 keg_dtor(void *arg, int size, void *udata)
1390 {
1391 	uma_keg_t keg;
1392 
1393 	keg = (uma_keg_t)arg;
1394 	mtx_lock(&keg->uk_lock);
1395 	if (keg->uk_free != 0) {
1396 		printf("Freed UMA keg was not empty (%d items). "
1397 		    " Lost %d pages of memory.\n",
1398 		    keg->uk_free, keg->uk_pages);
1399 	}
1400 	mtx_unlock(&keg->uk_lock);
1401 
1402 	if (keg->uk_flags & UMA_ZONE_HASH)
1403 		hash_free(&keg->uk_hash);
1404 
1405 	mtx_destroy(&keg->uk_lock);
1406 }
1407 
1408 /*
1409  * Zone header dtor.
1410  *
1411  * Arguments/Returns follow uma_dtor specifications
1412  *	udata  unused
1413  */
1414 static void
1415 zone_dtor(void *arg, int size, void *udata)
1416 {
1417 	uma_zone_t zone;
1418 	uma_keg_t keg;
1419 
1420 	zone = (uma_zone_t)arg;
1421 	keg = zone->uz_keg;
1422 
1423 	if (!(keg->uk_flags & UMA_ZFLAG_INTERNAL))
1424 		cache_drain(zone);
1425 
1426 	mtx_lock(&uma_mtx);
1427 	zone_drain(zone);
1428 	if (keg->uk_flags & UMA_ZONE_SECONDARY) {
1429 		LIST_REMOVE(zone, uz_link);
1430 		/*
1431 		 * XXX there are some races here where
1432 		 * the zone can be drained but zone lock
1433 		 * released and then refilled before we
1434 		 * remove it... we dont care for now
1435 		 */
1436 		ZONE_LOCK(zone);
1437 		if (LIST_EMPTY(&keg->uk_zones))
1438 			keg->uk_flags &= ~UMA_ZONE_SECONDARY;
1439 		ZONE_UNLOCK(zone);
1440 		mtx_unlock(&uma_mtx);
1441 	} else {
1442 		LIST_REMOVE(keg, uk_link);
1443 		LIST_REMOVE(zone, uz_link);
1444 		mtx_unlock(&uma_mtx);
1445 		uma_zfree_internal(kegs, keg, NULL, SKIP_NONE);
1446 	}
1447 	zone->uz_keg = NULL;
1448 }
1449 
1450 /*
1451  * Traverses every zone in the system and calls a callback
1452  *
1453  * Arguments:
1454  *	zfunc  A pointer to a function which accepts a zone
1455  *		as an argument.
1456  *
1457  * Returns:
1458  *	Nothing
1459  */
1460 static void
1461 zone_foreach(void (*zfunc)(uma_zone_t))
1462 {
1463 	uma_keg_t keg;
1464 	uma_zone_t zone;
1465 
1466 	mtx_lock(&uma_mtx);
1467 	LIST_FOREACH(keg, &uma_kegs, uk_link) {
1468 		LIST_FOREACH(zone, &keg->uk_zones, uz_link)
1469 			zfunc(zone);
1470 	}
1471 	mtx_unlock(&uma_mtx);
1472 }
1473 
1474 /* Public functions */
1475 /* See uma.h */
1476 void
1477 uma_startup(void *bootmem)
1478 {
1479 	struct uma_zctor_args args;
1480 	uma_slab_t slab;
1481 	u_int slabsize;
1482 	u_int objsize, totsize, wsize;
1483 	int i;
1484 
1485 #ifdef UMA_DEBUG
1486 	printf("Creating uma keg headers zone and keg.\n");
1487 #endif
1488 	/*
1489 	 * The general UMA lock is a recursion-allowed lock because
1490 	 * there is a code path where, while we're still configured
1491 	 * to use startup_alloc() for backend page allocations, we
1492 	 * may end up in uma_reclaim() which calls zone_foreach(zone_drain),
1493 	 * which grabs uma_mtx, only to later call into startup_alloc()
1494 	 * because while freeing we needed to allocate a bucket.  Since
1495 	 * startup_alloc() also takes uma_mtx, we need to be able to
1496 	 * recurse on it.
1497 	 */
1498 	mtx_init(&uma_mtx, "UMA lock", NULL, MTX_DEF | MTX_RECURSE);
1499 
1500 	/*
1501 	 * Figure out the maximum number of items-per-slab we'll have if
1502 	 * we're using the OFFPAGE slab header to track free items, given
1503 	 * all possible object sizes and the maximum desired wastage
1504 	 * (UMA_MAX_WASTE).
1505 	 *
1506 	 * We iterate until we find an object size for
1507 	 * which the calculated wastage in zone_small_init() will be
1508 	 * enough to warrant OFFPAGE.  Since wastedspace versus objsize
1509 	 * is an overall increasing see-saw function, we find the smallest
1510 	 * objsize such that the wastage is always acceptable for objects
1511 	 * with that objsize or smaller.  Since a smaller objsize always
1512 	 * generates a larger possible uma_max_ipers, we use this computed
1513 	 * objsize to calculate the largest ipers possible.  Since the
1514 	 * ipers calculated for OFFPAGE slab headers is always larger than
1515 	 * the ipers initially calculated in zone_small_init(), we use
1516 	 * the former's equation (UMA_SLAB_SIZE / keg->uk_rsize) to
1517 	 * obtain the maximum ipers possible for offpage slab headers.
1518 	 *
1519 	 * It should be noted that ipers versus objsize is an inversly
1520 	 * proportional function which drops off rather quickly so as
1521 	 * long as our UMA_MAX_WASTE is such that the objsize we calculate
1522 	 * falls into the portion of the inverse relation AFTER the steep
1523 	 * falloff, then uma_max_ipers shouldn't be too high (~10 on i386).
1524 	 *
1525 	 * Note that we have 8-bits (1 byte) to use as a freelist index
1526 	 * inside the actual slab header itself and this is enough to
1527 	 * accomodate us.  In the worst case, a UMA_SMALLEST_UNIT sized
1528 	 * object with offpage slab header would have ipers =
1529 	 * UMA_SLAB_SIZE / UMA_SMALLEST_UNIT (currently = 256), which is
1530 	 * 1 greater than what our byte-integer freelist index can
1531 	 * accomodate, but we know that this situation never occurs as
1532 	 * for UMA_SMALLEST_UNIT-sized objects, we will never calculate
1533 	 * that we need to go to offpage slab headers.  Or, if we do,
1534 	 * then we trap that condition below and panic in the INVARIANTS case.
1535 	 */
1536 	wsize = UMA_SLAB_SIZE - sizeof(struct uma_slab) - UMA_MAX_WASTE;
1537 	totsize = wsize;
1538 	objsize = UMA_SMALLEST_UNIT;
1539 	while (totsize >= wsize) {
1540 		totsize = (UMA_SLAB_SIZE - sizeof(struct uma_slab)) /
1541 		    (objsize + UMA_FRITM_SZ);
1542 		totsize *= (UMA_FRITM_SZ + objsize);
1543 		objsize++;
1544 	}
1545 	if (objsize > UMA_SMALLEST_UNIT)
1546 		objsize--;
1547 	uma_max_ipers = UMA_SLAB_SIZE / objsize;
1548 
1549 	wsize = UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt) - UMA_MAX_WASTE;
1550 	totsize = wsize;
1551 	objsize = UMA_SMALLEST_UNIT;
1552 	while (totsize >= wsize) {
1553 		totsize = (UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt)) /
1554 		    (objsize + UMA_FRITMREF_SZ);
1555 		totsize *= (UMA_FRITMREF_SZ + objsize);
1556 		objsize++;
1557 	}
1558 	if (objsize > UMA_SMALLEST_UNIT)
1559 		objsize--;
1560 	uma_max_ipers_ref = UMA_SLAB_SIZE / objsize;
1561 
1562 	KASSERT((uma_max_ipers_ref <= 255) && (uma_max_ipers <= 255),
1563 	    ("uma_startup: calculated uma_max_ipers values too large!"));
1564 
1565 #ifdef UMA_DEBUG
1566 	printf("Calculated uma_max_ipers (for OFFPAGE) is %d\n", uma_max_ipers);
1567 	printf("Calculated uma_max_ipers_slab (for OFFPAGE) is %d\n",
1568 	    uma_max_ipers_ref);
1569 #endif
1570 
1571 	/* "manually" create the initial zone */
1572 	args.name = "UMA Kegs";
1573 	args.size = sizeof(struct uma_keg);
1574 	args.ctor = keg_ctor;
1575 	args.dtor = keg_dtor;
1576 	args.uminit = zero_init;
1577 	args.fini = NULL;
1578 	args.keg = &masterkeg;
1579 	args.align = 32 - 1;
1580 	args.flags = UMA_ZFLAG_INTERNAL;
1581 	/* The initial zone has no Per cpu queues so it's smaller */
1582 	zone_ctor(kegs, sizeof(struct uma_zone), &args, M_WAITOK);
1583 
1584 #ifdef UMA_DEBUG
1585 	printf("Filling boot free list.\n");
1586 #endif
1587 	for (i = 0; i < UMA_BOOT_PAGES; i++) {
1588 		slab = (uma_slab_t)((u_int8_t *)bootmem + (i * UMA_SLAB_SIZE));
1589 		slab->us_data = (u_int8_t *)slab;
1590 		slab->us_flags = UMA_SLAB_BOOT;
1591 		LIST_INSERT_HEAD(&uma_boot_pages, slab, us_link);
1592 		uma_boot_free++;
1593 	}
1594 
1595 #ifdef UMA_DEBUG
1596 	printf("Creating uma zone headers zone and keg.\n");
1597 #endif
1598 	args.name = "UMA Zones";
1599 	args.size = sizeof(struct uma_zone) +
1600 	    (sizeof(struct uma_cache) * (mp_maxid + 1));
1601 	args.ctor = zone_ctor;
1602 	args.dtor = zone_dtor;
1603 	args.uminit = zero_init;
1604 	args.fini = NULL;
1605 	args.keg = NULL;
1606 	args.align = 32 - 1;
1607 	args.flags = UMA_ZFLAG_INTERNAL;
1608 	/* The initial zone has no Per cpu queues so it's smaller */
1609 	zone_ctor(zones, sizeof(struct uma_zone), &args, M_WAITOK);
1610 
1611 #ifdef UMA_DEBUG
1612 	printf("Initializing pcpu cache locks.\n");
1613 #endif
1614 	/* Initialize the pcpu cache lock set once and for all */
1615 	for (i = 0; i <= mp_maxid; i++)
1616 		CPU_LOCK_INIT(i);
1617 
1618 #ifdef UMA_DEBUG
1619 	printf("Creating slab and hash zones.\n");
1620 #endif
1621 
1622 	/*
1623 	 * This is the max number of free list items we'll have with
1624 	 * offpage slabs.
1625 	 */
1626 	slabsize = uma_max_ipers * UMA_FRITM_SZ;
1627 	slabsize += sizeof(struct uma_slab);
1628 
1629 	/* Now make a zone for slab headers */
1630 	slabzone = uma_zcreate("UMA Slabs",
1631 				slabsize,
1632 				NULL, NULL, NULL, NULL,
1633 				UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
1634 
1635 	/*
1636 	 * We also create a zone for the bigger slabs with reference
1637 	 * counts in them, to accomodate UMA_ZONE_REFCNT zones.
1638 	 */
1639 	slabsize = uma_max_ipers_ref * UMA_FRITMREF_SZ;
1640 	slabsize += sizeof(struct uma_slab_refcnt);
1641 	slabrefzone = uma_zcreate("UMA RCntSlabs",
1642 				  slabsize,
1643 				  NULL, NULL, NULL, NULL,
1644 				  UMA_ALIGN_PTR,
1645 				  UMA_ZFLAG_INTERNAL);
1646 
1647 	hashzone = uma_zcreate("UMA Hash",
1648 	    sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT,
1649 	    NULL, NULL, NULL, NULL,
1650 	    UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
1651 
1652 	bucket_init();
1653 
1654 #ifdef UMA_MD_SMALL_ALLOC
1655 	booted = 1;
1656 #endif
1657 
1658 #ifdef UMA_DEBUG
1659 	printf("UMA startup complete.\n");
1660 #endif
1661 }
1662 
1663 /* see uma.h */
1664 void
1665 uma_startup2(void)
1666 {
1667 	booted = 1;
1668 	bucket_enable();
1669 #ifdef UMA_DEBUG
1670 	printf("UMA startup2 complete.\n");
1671 #endif
1672 }
1673 
1674 /*
1675  * Initialize our callout handle
1676  *
1677  */
1678 
1679 static void
1680 uma_startup3(void)
1681 {
1682 #ifdef UMA_DEBUG
1683 	printf("Starting callout.\n");
1684 #endif
1685 	callout_init(&uma_callout, CALLOUT_MPSAFE);
1686 	callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
1687 #ifdef UMA_DEBUG
1688 	printf("UMA startup3 complete.\n");
1689 #endif
1690 }
1691 
1692 static uma_zone_t
1693 uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini,
1694 		int align, u_int16_t flags)
1695 {
1696 	struct uma_kctor_args args;
1697 
1698 	args.size = size;
1699 	args.uminit = uminit;
1700 	args.fini = fini;
1701 	args.align = align;
1702 	args.flags = flags;
1703 	args.zone = zone;
1704 	return (uma_zalloc_internal(kegs, &args, M_WAITOK));
1705 }
1706 
1707 /* See uma.h */
1708 uma_zone_t
1709 uma_zcreate(char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
1710 		uma_init uminit, uma_fini fini, int align, u_int16_t flags)
1711 
1712 {
1713 	struct uma_zctor_args args;
1714 
1715 	/* This stuff is essential for the zone ctor */
1716 	args.name = name;
1717 	args.size = size;
1718 	args.ctor = ctor;
1719 	args.dtor = dtor;
1720 	args.uminit = uminit;
1721 	args.fini = fini;
1722 	args.align = align;
1723 	args.flags = flags;
1724 	args.keg = NULL;
1725 
1726 	return (uma_zalloc_internal(zones, &args, M_WAITOK));
1727 }
1728 
1729 /* See uma.h */
1730 uma_zone_t
1731 uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
1732 		    uma_init zinit, uma_fini zfini, uma_zone_t master)
1733 {
1734 	struct uma_zctor_args args;
1735 
1736 	args.name = name;
1737 	args.size = master->uz_keg->uk_size;
1738 	args.ctor = ctor;
1739 	args.dtor = dtor;
1740 	args.uminit = zinit;
1741 	args.fini = zfini;
1742 	args.align = master->uz_keg->uk_align;
1743 	args.flags = master->uz_keg->uk_flags | UMA_ZONE_SECONDARY;
1744 	args.keg = master->uz_keg;
1745 
1746 	return (uma_zalloc_internal(zones, &args, M_WAITOK));
1747 }
1748 
1749 /* See uma.h */
1750 void
1751 uma_zdestroy(uma_zone_t zone)
1752 {
1753 	uma_zfree_internal(zones, zone, NULL, SKIP_NONE);
1754 }
1755 
1756 /* See uma.h */
1757 void *
1758 uma_zalloc_arg(uma_zone_t zone, void *udata, int flags)
1759 {
1760 	void *item;
1761 	uma_cache_t cache;
1762 	uma_bucket_t bucket;
1763 	int cpu;
1764 	int badness;
1765 
1766 	/* This is the fast path allocation */
1767 #ifdef UMA_DEBUG_ALLOC_1
1768 	printf("Allocating one item from %s(%p)\n", zone->uz_name, zone);
1769 #endif
1770 	CTR3(KTR_UMA, "uma_zalloc_arg thread %x zone %s flags %d", curthread,
1771 	    zone->uz_name, flags);
1772 
1773 	if (!(flags & M_NOWAIT)) {
1774 		KASSERT(curthread->td_intr_nesting_level == 0,
1775 		   ("malloc(M_WAITOK) in interrupt context"));
1776 		if (nosleepwithlocks) {
1777 #ifdef WITNESS
1778 			badness = WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
1779 			    NULL,
1780 			    "malloc(M_WAITOK) of \"%s\", forcing M_NOWAIT",
1781 			    zone->uz_name);
1782 #else
1783 			badness = 1;
1784 #endif
1785 		} else {
1786 			badness = 0;
1787 #ifdef WITNESS
1788 			WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
1789 			    "malloc(M_WAITOK) of \"%s\"", zone->uz_name);
1790 #endif
1791 		}
1792 		if (badness) {
1793 			flags &= ~M_WAITOK;
1794 			flags |= M_NOWAIT;
1795 		}
1796 	}
1797 
1798 zalloc_restart:
1799 	cpu = PCPU_GET(cpuid);
1800 	CPU_LOCK(cpu);
1801 	cache = &zone->uz_cpu[cpu];
1802 
1803 zalloc_start:
1804 	bucket = cache->uc_allocbucket;
1805 
1806 	if (bucket) {
1807 		if (bucket->ub_cnt > 0) {
1808 			bucket->ub_cnt--;
1809 			item = bucket->ub_bucket[bucket->ub_cnt];
1810 #ifdef INVARIANTS
1811 			bucket->ub_bucket[bucket->ub_cnt] = NULL;
1812 #endif
1813 			KASSERT(item != NULL,
1814 			    ("uma_zalloc: Bucket pointer mangled."));
1815 			cache->uc_allocs++;
1816 #ifdef INVARIANTS
1817 			ZONE_LOCK(zone);
1818 			uma_dbg_alloc(zone, NULL, item);
1819 			ZONE_UNLOCK(zone);
1820 #endif
1821 			CPU_UNLOCK(cpu);
1822 			if (zone->uz_ctor != NULL) {
1823 				if (zone->uz_ctor(item, zone->uz_keg->uk_size,
1824 				    udata, flags) != 0) {
1825 					uma_zfree_internal(zone, item, udata,
1826 					    SKIP_DTOR);
1827 					return (NULL);
1828 				}
1829 			}
1830 			if (flags & M_ZERO)
1831 				bzero(item, zone->uz_keg->uk_size);
1832 			return (item);
1833 		} else if (cache->uc_freebucket) {
1834 			/*
1835 			 * We have run out of items in our allocbucket.
1836 			 * See if we can switch with our free bucket.
1837 			 */
1838 			if (cache->uc_freebucket->ub_cnt > 0) {
1839 #ifdef UMA_DEBUG_ALLOC
1840 				printf("uma_zalloc: Swapping empty with"
1841 				    " alloc.\n");
1842 #endif
1843 				bucket = cache->uc_freebucket;
1844 				cache->uc_freebucket = cache->uc_allocbucket;
1845 				cache->uc_allocbucket = bucket;
1846 
1847 				goto zalloc_start;
1848 			}
1849 		}
1850 	}
1851 	ZONE_LOCK(zone);
1852 	/* Since we have locked the zone we may as well send back our stats */
1853 	zone->uz_allocs += cache->uc_allocs;
1854 	cache->uc_allocs = 0;
1855 
1856 	/* Our old one is now a free bucket */
1857 	if (cache->uc_allocbucket) {
1858 		KASSERT(cache->uc_allocbucket->ub_cnt == 0,
1859 		    ("uma_zalloc_arg: Freeing a non free bucket."));
1860 		LIST_INSERT_HEAD(&zone->uz_free_bucket,
1861 		    cache->uc_allocbucket, ub_link);
1862 		cache->uc_allocbucket = NULL;
1863 	}
1864 
1865 	/* Check the free list for a new alloc bucket */
1866 	if ((bucket = LIST_FIRST(&zone->uz_full_bucket)) != NULL) {
1867 		KASSERT(bucket->ub_cnt != 0,
1868 		    ("uma_zalloc_arg: Returning an empty bucket."));
1869 
1870 		LIST_REMOVE(bucket, ub_link);
1871 		cache->uc_allocbucket = bucket;
1872 		ZONE_UNLOCK(zone);
1873 		goto zalloc_start;
1874 	}
1875 	/* We are no longer associated with this cpu!!! */
1876 	CPU_UNLOCK(cpu);
1877 
1878 	/* Bump up our uz_count so we get here less */
1879 	if (zone->uz_count < BUCKET_MAX)
1880 		zone->uz_count++;
1881 
1882 	/*
1883 	 * Now lets just fill a bucket and put it on the free list.  If that
1884 	 * works we'll restart the allocation from the begining.
1885 	 */
1886 	if (uma_zalloc_bucket(zone, flags)) {
1887 		ZONE_UNLOCK(zone);
1888 		goto zalloc_restart;
1889 	}
1890 	ZONE_UNLOCK(zone);
1891 	/*
1892 	 * We may not be able to get a bucket so return an actual item.
1893 	 */
1894 #ifdef UMA_DEBUG
1895 	printf("uma_zalloc_arg: Bucketzone returned NULL\n");
1896 #endif
1897 
1898 	return (uma_zalloc_internal(zone, udata, flags));
1899 }
1900 
1901 static uma_slab_t
1902 uma_zone_slab(uma_zone_t zone, int flags)
1903 {
1904 	uma_slab_t slab;
1905 	uma_keg_t keg;
1906 
1907 	keg = zone->uz_keg;
1908 
1909 	/*
1910 	 * This is to prevent us from recursively trying to allocate
1911 	 * buckets.  The problem is that if an allocation forces us to
1912 	 * grab a new bucket we will call page_alloc, which will go off
1913 	 * and cause the vm to allocate vm_map_entries.  If we need new
1914 	 * buckets there too we will recurse in kmem_alloc and bad
1915 	 * things happen.  So instead we return a NULL bucket, and make
1916 	 * the code that allocates buckets smart enough to deal with it
1917 	 */
1918 	if (keg->uk_flags & UMA_ZFLAG_INTERNAL && keg->uk_recurse != 0)
1919 		return (NULL);
1920 
1921 	slab = NULL;
1922 
1923 	for (;;) {
1924 		/*
1925 		 * Find a slab with some space.  Prefer slabs that are partially
1926 		 * used over those that are totally full.  This helps to reduce
1927 		 * fragmentation.
1928 		 */
1929 		if (keg->uk_free != 0) {
1930 			if (!LIST_EMPTY(&keg->uk_part_slab)) {
1931 				slab = LIST_FIRST(&keg->uk_part_slab);
1932 			} else {
1933 				slab = LIST_FIRST(&keg->uk_free_slab);
1934 				LIST_REMOVE(slab, us_link);
1935 				LIST_INSERT_HEAD(&keg->uk_part_slab, slab,
1936 				    us_link);
1937 			}
1938 			return (slab);
1939 		}
1940 
1941 		/*
1942 		 * M_NOVM means don't ask at all!
1943 		 */
1944 		if (flags & M_NOVM)
1945 			break;
1946 
1947 		if (keg->uk_maxpages &&
1948 		    keg->uk_pages >= keg->uk_maxpages) {
1949 			keg->uk_flags |= UMA_ZFLAG_FULL;
1950 
1951 			if (flags & M_NOWAIT)
1952 				break;
1953 			else
1954 				msleep(keg, &keg->uk_lock, PVM,
1955 				    "zonelimit", 0);
1956 			continue;
1957 		}
1958 		keg->uk_recurse++;
1959 		slab = slab_zalloc(zone, flags);
1960 		keg->uk_recurse--;
1961 
1962 		/*
1963 		 * If we got a slab here it's safe to mark it partially used
1964 		 * and return.  We assume that the caller is going to remove
1965 		 * at least one item.
1966 		 */
1967 		if (slab) {
1968 			LIST_INSERT_HEAD(&keg->uk_part_slab, slab, us_link);
1969 			return (slab);
1970 		}
1971 		/*
1972 		 * We might not have been able to get a slab but another cpu
1973 		 * could have while we were unlocked.  Check again before we
1974 		 * fail.
1975 		 */
1976 		if (flags & M_NOWAIT)
1977 			flags |= M_NOVM;
1978 	}
1979 	return (slab);
1980 }
1981 
1982 static void *
1983 uma_slab_alloc(uma_zone_t zone, uma_slab_t slab)
1984 {
1985 	uma_keg_t keg;
1986 	void *item;
1987 	u_int8_t freei;
1988 
1989 	keg = zone->uz_keg;
1990 
1991 	freei = slab->us_firstfree;
1992 	slab->us_firstfree = slab->us_freelist[freei].us_item;
1993 	item = slab->us_data + (keg->uk_rsize * freei);
1994 
1995 	slab->us_freecount--;
1996 	keg->uk_free--;
1997 #ifdef INVARIANTS
1998 	uma_dbg_alloc(zone, slab, item);
1999 #endif
2000 	/* Move this slab to the full list */
2001 	if (slab->us_freecount == 0) {
2002 		LIST_REMOVE(slab, us_link);
2003 		LIST_INSERT_HEAD(&keg->uk_full_slab, slab, us_link);
2004 	}
2005 
2006 	return (item);
2007 }
2008 
2009 static int
2010 uma_zalloc_bucket(uma_zone_t zone, int flags)
2011 {
2012 	uma_bucket_t bucket;
2013 	uma_slab_t slab;
2014 	int16_t saved;
2015 	int max, origflags = flags;
2016 
2017 	/*
2018 	 * Try this zone's free list first so we don't allocate extra buckets.
2019 	 */
2020 	if ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) {
2021 		KASSERT(bucket->ub_cnt == 0,
2022 		    ("uma_zalloc_bucket: Bucket on free list is not empty."));
2023 		LIST_REMOVE(bucket, ub_link);
2024 	} else {
2025 		int bflags;
2026 
2027 		bflags = (flags & ~M_ZERO);
2028 		if (zone->uz_keg->uk_flags & UMA_ZFLAG_CACHEONLY)
2029 			bflags |= M_NOVM;
2030 
2031 		ZONE_UNLOCK(zone);
2032 		bucket = bucket_alloc(zone->uz_count, bflags);
2033 		ZONE_LOCK(zone);
2034 	}
2035 
2036 	if (bucket == NULL)
2037 		return (0);
2038 
2039 #ifdef SMP
2040 	/*
2041 	 * This code is here to limit the number of simultaneous bucket fills
2042 	 * for any given zone to the number of per cpu caches in this zone. This
2043 	 * is done so that we don't allocate more memory than we really need.
2044 	 */
2045 	if (zone->uz_fills >= mp_ncpus)
2046 		goto done;
2047 
2048 #endif
2049 	zone->uz_fills++;
2050 
2051 	max = MIN(bucket->ub_entries, zone->uz_count);
2052 	/* Try to keep the buckets totally full */
2053 	saved = bucket->ub_cnt;
2054 	while (bucket->ub_cnt < max &&
2055 	    (slab = uma_zone_slab(zone, flags)) != NULL) {
2056 		while (slab->us_freecount && bucket->ub_cnt < max) {
2057 			bucket->ub_bucket[bucket->ub_cnt++] =
2058 			    uma_slab_alloc(zone, slab);
2059 		}
2060 
2061 		/* Don't block on the next fill */
2062 		flags |= M_NOWAIT;
2063 	}
2064 
2065 	/*
2066 	 * We unlock here because we need to call the zone's init.
2067 	 * It should be safe to unlock because the slab dealt with
2068 	 * above is already on the appropriate list within the keg
2069 	 * and the bucket we filled is not yet on any list, so we
2070 	 * own it.
2071 	 */
2072 	if (zone->uz_init != NULL) {
2073 		int i;
2074 
2075 		ZONE_UNLOCK(zone);
2076 		for (i = saved; i < bucket->ub_cnt; i++)
2077 			if (zone->uz_init(bucket->ub_bucket[i],
2078 			    zone->uz_keg->uk_size, origflags) != 0)
2079 				break;
2080 		/*
2081 		 * If we couldn't initialize the whole bucket, put the
2082 		 * rest back onto the freelist.
2083 		 */
2084 		if (i != bucket->ub_cnt) {
2085 			int j;
2086 
2087 			for (j = i; j < bucket->ub_cnt; j++)
2088 				uma_zfree_internal(zone, bucket->ub_bucket[j],
2089 				    NULL, SKIP_FINI);
2090 			bucket->ub_cnt = i;
2091 		}
2092 		ZONE_LOCK(zone);
2093 	}
2094 
2095 	zone->uz_fills--;
2096 	if (bucket->ub_cnt != 0) {
2097 		LIST_INSERT_HEAD(&zone->uz_full_bucket,
2098 		    bucket, ub_link);
2099 		return (1);
2100 	}
2101 #ifdef SMP
2102 done:
2103 #endif
2104 	bucket_free(bucket);
2105 
2106 	return (0);
2107 }
2108 /*
2109  * Allocates an item for an internal zone
2110  *
2111  * Arguments
2112  *	zone   The zone to alloc for.
2113  *	udata  The data to be passed to the constructor.
2114  *	flags  M_WAITOK, M_NOWAIT, M_ZERO.
2115  *
2116  * Returns
2117  *	NULL if there is no memory and M_NOWAIT is set
2118  *	An item if successful
2119  */
2120 
2121 static void *
2122 uma_zalloc_internal(uma_zone_t zone, void *udata, int flags)
2123 {
2124 	uma_keg_t keg;
2125 	uma_slab_t slab;
2126 	void *item;
2127 
2128 	item = NULL;
2129 	keg = zone->uz_keg;
2130 
2131 #ifdef UMA_DEBUG_ALLOC
2132 	printf("INTERNAL: Allocating one item from %s(%p)\n", zone->uz_name, zone);
2133 #endif
2134 	ZONE_LOCK(zone);
2135 
2136 	slab = uma_zone_slab(zone, flags);
2137 	if (slab == NULL) {
2138 		ZONE_UNLOCK(zone);
2139 		return (NULL);
2140 	}
2141 
2142 	item = uma_slab_alloc(zone, slab);
2143 
2144 	ZONE_UNLOCK(zone);
2145 
2146 	/*
2147 	 * We have to call both the zone's init (not the keg's init)
2148 	 * and the zone's ctor.  This is because the item is going from
2149 	 * a keg slab directly to the user, and the user is expecting it
2150 	 * to be both zone-init'd as well as zone-ctor'd.
2151 	 */
2152 	if (zone->uz_init != NULL) {
2153 		if (zone->uz_init(item, keg->uk_size, flags) != 0) {
2154 			uma_zfree_internal(zone, item, udata, SKIP_FINI);
2155 			return (NULL);
2156 		}
2157 	}
2158 	if (zone->uz_ctor != NULL) {
2159 		if (zone->uz_ctor(item, keg->uk_size, udata, flags) != 0) {
2160 			uma_zfree_internal(zone, item, udata, SKIP_DTOR);
2161 			return (NULL);
2162 		}
2163 	}
2164 	if (flags & M_ZERO)
2165 		bzero(item, keg->uk_size);
2166 
2167 	return (item);
2168 }
2169 
2170 /* See uma.h */
2171 void
2172 uma_zfree_arg(uma_zone_t zone, void *item, void *udata)
2173 {
2174 	uma_keg_t keg;
2175 	uma_cache_t cache;
2176 	uma_bucket_t bucket;
2177 	int bflags;
2178 	int cpu;
2179 	enum zfreeskip skip;
2180 
2181 	/* This is the fast path free */
2182 	skip = SKIP_NONE;
2183 	keg = zone->uz_keg;
2184 
2185 #ifdef UMA_DEBUG_ALLOC_1
2186 	printf("Freeing item %p to %s(%p)\n", item, zone->uz_name, zone);
2187 #endif
2188 	CTR2(KTR_UMA, "uma_zfree_arg thread %x zone %s", curthread,
2189 	    zone->uz_name);
2190 
2191 	/*
2192 	 * The race here is acceptable.  If we miss it we'll just have to wait
2193 	 * a little longer for the limits to be reset.
2194 	 */
2195 
2196 	if (keg->uk_flags & UMA_ZFLAG_FULL)
2197 		goto zfree_internal;
2198 
2199 	if (zone->uz_dtor) {
2200 		zone->uz_dtor(item, keg->uk_size, udata);
2201 		skip = SKIP_DTOR;
2202 	}
2203 
2204 zfree_restart:
2205 	cpu = PCPU_GET(cpuid);
2206 	CPU_LOCK(cpu);
2207 	cache = &zone->uz_cpu[cpu];
2208 
2209 zfree_start:
2210 	bucket = cache->uc_freebucket;
2211 
2212 	if (bucket) {
2213 		/*
2214 		 * Do we have room in our bucket? It is OK for this uz count
2215 		 * check to be slightly out of sync.
2216 		 */
2217 
2218 		if (bucket->ub_cnt < bucket->ub_entries) {
2219 			KASSERT(bucket->ub_bucket[bucket->ub_cnt] == NULL,
2220 			    ("uma_zfree: Freeing to non free bucket index."));
2221 			bucket->ub_bucket[bucket->ub_cnt] = item;
2222 			bucket->ub_cnt++;
2223 #ifdef INVARIANTS
2224 			ZONE_LOCK(zone);
2225 			if (keg->uk_flags & UMA_ZONE_MALLOC)
2226 				uma_dbg_free(zone, udata, item);
2227 			else
2228 				uma_dbg_free(zone, NULL, item);
2229 			ZONE_UNLOCK(zone);
2230 #endif
2231 			CPU_UNLOCK(cpu);
2232 			return;
2233 		} else if (cache->uc_allocbucket) {
2234 #ifdef UMA_DEBUG_ALLOC
2235 			printf("uma_zfree: Swapping buckets.\n");
2236 #endif
2237 			/*
2238 			 * We have run out of space in our freebucket.
2239 			 * See if we can switch with our alloc bucket.
2240 			 */
2241 			if (cache->uc_allocbucket->ub_cnt <
2242 			    cache->uc_freebucket->ub_cnt) {
2243 				bucket = cache->uc_freebucket;
2244 				cache->uc_freebucket = cache->uc_allocbucket;
2245 				cache->uc_allocbucket = bucket;
2246 				goto zfree_start;
2247 			}
2248 		}
2249 	}
2250 	/*
2251 	 * We can get here for two reasons:
2252 	 *
2253 	 * 1) The buckets are NULL
2254 	 * 2) The alloc and free buckets are both somewhat full.
2255 	 */
2256 
2257 	ZONE_LOCK(zone);
2258 
2259 	bucket = cache->uc_freebucket;
2260 	cache->uc_freebucket = NULL;
2261 
2262 	/* Can we throw this on the zone full list? */
2263 	if (bucket != NULL) {
2264 #ifdef UMA_DEBUG_ALLOC
2265 		printf("uma_zfree: Putting old bucket on the free list.\n");
2266 #endif
2267 		/* ub_cnt is pointing to the last free item */
2268 		KASSERT(bucket->ub_cnt != 0,
2269 		    ("uma_zfree: Attempting to insert an empty bucket onto the full list.\n"));
2270 		LIST_INSERT_HEAD(&zone->uz_full_bucket,
2271 		    bucket, ub_link);
2272 	}
2273 	if ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) {
2274 		LIST_REMOVE(bucket, ub_link);
2275 		ZONE_UNLOCK(zone);
2276 		cache->uc_freebucket = bucket;
2277 		goto zfree_start;
2278 	}
2279 	/* We're done with this CPU now */
2280 	CPU_UNLOCK(cpu);
2281 
2282 	/* And the zone.. */
2283 	ZONE_UNLOCK(zone);
2284 
2285 #ifdef UMA_DEBUG_ALLOC
2286 	printf("uma_zfree: Allocating new free bucket.\n");
2287 #endif
2288 	bflags = M_NOWAIT;
2289 
2290 	if (keg->uk_flags & UMA_ZFLAG_CACHEONLY)
2291 		bflags |= M_NOVM;
2292 	bucket = bucket_alloc(zone->uz_count, bflags);
2293 	if (bucket) {
2294 		ZONE_LOCK(zone);
2295 		LIST_INSERT_HEAD(&zone->uz_free_bucket,
2296 		    bucket, ub_link);
2297 		ZONE_UNLOCK(zone);
2298 		goto zfree_restart;
2299 	}
2300 
2301 	/*
2302 	 * If nothing else caught this, we'll just do an internal free.
2303 	 */
2304 
2305 zfree_internal:
2306 
2307 #ifdef INVARIANTS
2308 	/*
2309 	 * If we need to skip the dtor and the uma_dbg_free in
2310 	 * uma_zfree_internal because we've already called the dtor
2311 	 * above, but we ended up here, then we need to make sure
2312 	 * that we take care of the uma_dbg_free immediately.
2313 	 */
2314 	if (skip) {
2315 		ZONE_LOCK(zone);
2316 		if (keg->uk_flags & UMA_ZONE_MALLOC)
2317 			uma_dbg_free(zone, udata, item);
2318 		else
2319 			uma_dbg_free(zone, NULL, item);
2320 		ZONE_UNLOCK(zone);
2321 	}
2322 #endif
2323 	uma_zfree_internal(zone, item, udata, skip);
2324 
2325 	return;
2326 }
2327 
2328 /*
2329  * Frees an item to an INTERNAL zone or allocates a free bucket
2330  *
2331  * Arguments:
2332  *	zone   The zone to free to
2333  *	item   The item we're freeing
2334  *	udata  User supplied data for the dtor
2335  *	skip   Skip dtors and finis
2336  */
2337 static void
2338 uma_zfree_internal(uma_zone_t zone, void *item, void *udata,
2339     enum zfreeskip skip)
2340 {
2341 	uma_slab_t slab;
2342 	uma_keg_t keg;
2343 	u_int8_t *mem;
2344 	u_int8_t freei;
2345 
2346 	keg = zone->uz_keg;
2347 
2348 	if (skip < SKIP_DTOR && zone->uz_dtor)
2349 		zone->uz_dtor(item, keg->uk_size, udata);
2350 	if (skip < SKIP_FINI && zone->uz_fini)
2351 		zone->uz_fini(item, keg->uk_size);
2352 
2353 	ZONE_LOCK(zone);
2354 
2355 	if (!(keg->uk_flags & UMA_ZONE_MALLOC)) {
2356 		mem = (u_int8_t *)((unsigned long)item & (~UMA_SLAB_MASK));
2357 		if (keg->uk_flags & UMA_ZONE_HASH)
2358 			slab = hash_sfind(&keg->uk_hash, mem);
2359 		else {
2360 			mem += keg->uk_pgoff;
2361 			slab = (uma_slab_t)mem;
2362 		}
2363 	} else {
2364 		slab = (uma_slab_t)udata;
2365 	}
2366 
2367 	/* Do we need to remove from any lists? */
2368 	if (slab->us_freecount+1 == keg->uk_ipers) {
2369 		LIST_REMOVE(slab, us_link);
2370 		LIST_INSERT_HEAD(&keg->uk_free_slab, slab, us_link);
2371 	} else if (slab->us_freecount == 0) {
2372 		LIST_REMOVE(slab, us_link);
2373 		LIST_INSERT_HEAD(&keg->uk_part_slab, slab, us_link);
2374 	}
2375 
2376 	/* Slab management stuff */
2377 	freei = ((unsigned long)item - (unsigned long)slab->us_data)
2378 		/ keg->uk_rsize;
2379 
2380 #ifdef INVARIANTS
2381 	if (!skip)
2382 		uma_dbg_free(zone, slab, item);
2383 #endif
2384 
2385 	slab->us_freelist[freei].us_item = slab->us_firstfree;
2386 	slab->us_firstfree = freei;
2387 	slab->us_freecount++;
2388 
2389 	/* Zone statistics */
2390 	keg->uk_free++;
2391 
2392 	if (keg->uk_flags & UMA_ZFLAG_FULL) {
2393 		if (keg->uk_pages < keg->uk_maxpages)
2394 			keg->uk_flags &= ~UMA_ZFLAG_FULL;
2395 
2396 		/* We can handle one more allocation */
2397 		wakeup_one(keg);
2398 	}
2399 
2400 	ZONE_UNLOCK(zone);
2401 }
2402 
2403 /* See uma.h */
2404 void
2405 uma_zone_set_max(uma_zone_t zone, int nitems)
2406 {
2407 	uma_keg_t keg;
2408 
2409 	keg = zone->uz_keg;
2410 	ZONE_LOCK(zone);
2411 	if (keg->uk_ppera > 1)
2412 		keg->uk_maxpages = nitems * keg->uk_ppera;
2413 	else
2414 		keg->uk_maxpages = nitems / keg->uk_ipers;
2415 
2416 	if (keg->uk_maxpages * keg->uk_ipers < nitems)
2417 		keg->uk_maxpages++;
2418 
2419 	ZONE_UNLOCK(zone);
2420 }
2421 
2422 /* See uma.h */
2423 void
2424 uma_zone_set_init(uma_zone_t zone, uma_init uminit)
2425 {
2426 	ZONE_LOCK(zone);
2427 	KASSERT(zone->uz_keg->uk_pages == 0,
2428 	    ("uma_zone_set_init on non-empty keg"));
2429 	zone->uz_keg->uk_init = uminit;
2430 	ZONE_UNLOCK(zone);
2431 }
2432 
2433 /* See uma.h */
2434 void
2435 uma_zone_set_fini(uma_zone_t zone, uma_fini fini)
2436 {
2437 	ZONE_LOCK(zone);
2438 	KASSERT(zone->uz_keg->uk_pages == 0,
2439 	    ("uma_zone_set_fini on non-empty keg"));
2440 	zone->uz_keg->uk_fini = fini;
2441 	ZONE_UNLOCK(zone);
2442 }
2443 
2444 /* See uma.h */
2445 void
2446 uma_zone_set_zinit(uma_zone_t zone, uma_init zinit)
2447 {
2448 	ZONE_LOCK(zone);
2449 	KASSERT(zone->uz_keg->uk_pages == 0,
2450 	    ("uma_zone_set_zinit on non-empty keg"));
2451 	zone->uz_init = zinit;
2452 	ZONE_UNLOCK(zone);
2453 }
2454 
2455 /* See uma.h */
2456 void
2457 uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini)
2458 {
2459 	ZONE_LOCK(zone);
2460 	KASSERT(zone->uz_keg->uk_pages == 0,
2461 	    ("uma_zone_set_zfini on non-empty keg"));
2462 	zone->uz_fini = zfini;
2463 	ZONE_UNLOCK(zone);
2464 }
2465 
2466 /* See uma.h */
2467 /* XXX uk_freef is not actually used with the zone locked */
2468 void
2469 uma_zone_set_freef(uma_zone_t zone, uma_free freef)
2470 {
2471 	ZONE_LOCK(zone);
2472 	zone->uz_keg->uk_freef = freef;
2473 	ZONE_UNLOCK(zone);
2474 }
2475 
2476 /* See uma.h */
2477 /* XXX uk_allocf is not actually used with the zone locked */
2478 void
2479 uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf)
2480 {
2481 	ZONE_LOCK(zone);
2482 	zone->uz_keg->uk_flags |= UMA_ZFLAG_PRIVALLOC;
2483 	zone->uz_keg->uk_allocf = allocf;
2484 	ZONE_UNLOCK(zone);
2485 }
2486 
2487 /* See uma.h */
2488 int
2489 uma_zone_set_obj(uma_zone_t zone, struct vm_object *obj, int count)
2490 {
2491 	uma_keg_t keg;
2492 	vm_offset_t kva;
2493 	int pages;
2494 
2495 	keg = zone->uz_keg;
2496 	pages = count / keg->uk_ipers;
2497 
2498 	if (pages * keg->uk_ipers < count)
2499 		pages++;
2500 
2501 	kva = kmem_alloc_nofault(kernel_map, pages * UMA_SLAB_SIZE);
2502 
2503 	if (kva == 0)
2504 		return (0);
2505 	if (obj == NULL) {
2506 		obj = vm_object_allocate(OBJT_DEFAULT,
2507 		    pages);
2508 	} else {
2509 		VM_OBJECT_LOCK_INIT(obj, "uma object");
2510 		_vm_object_allocate(OBJT_DEFAULT,
2511 		    pages, obj);
2512 	}
2513 	ZONE_LOCK(zone);
2514 	keg->uk_kva = kva;
2515 	keg->uk_obj = obj;
2516 	keg->uk_maxpages = pages;
2517 	keg->uk_allocf = obj_alloc;
2518 	keg->uk_flags |= UMA_ZONE_NOFREE | UMA_ZFLAG_PRIVALLOC;
2519 	ZONE_UNLOCK(zone);
2520 	return (1);
2521 }
2522 
2523 /* See uma.h */
2524 void
2525 uma_prealloc(uma_zone_t zone, int items)
2526 {
2527 	int slabs;
2528 	uma_slab_t slab;
2529 	uma_keg_t keg;
2530 
2531 	keg = zone->uz_keg;
2532 	ZONE_LOCK(zone);
2533 	slabs = items / keg->uk_ipers;
2534 	if (slabs * keg->uk_ipers < items)
2535 		slabs++;
2536 	while (slabs > 0) {
2537 		slab = slab_zalloc(zone, M_WAITOK);
2538 		LIST_INSERT_HEAD(&keg->uk_free_slab, slab, us_link);
2539 		slabs--;
2540 	}
2541 	ZONE_UNLOCK(zone);
2542 }
2543 
2544 /* See uma.h */
2545 u_int32_t *
2546 uma_find_refcnt(uma_zone_t zone, void *item)
2547 {
2548 	uma_slabrefcnt_t slab;
2549 	uma_keg_t keg;
2550 	u_int32_t *refcnt;
2551 	int idx;
2552 
2553 	keg = zone->uz_keg;
2554 	slab = (uma_slabrefcnt_t)vtoslab((vm_offset_t)item & (~UMA_SLAB_MASK));
2555 	KASSERT(slab != NULL,
2556 	    ("uma_find_refcnt(): zone possibly not UMA_ZONE_REFCNT"));
2557 	idx = ((unsigned long)item - (unsigned long)slab->us_data)
2558 	    / keg->uk_rsize;
2559 	refcnt = &(slab->us_freelist[idx].us_refcnt);
2560 	return refcnt;
2561 }
2562 
2563 /* See uma.h */
2564 void
2565 uma_reclaim(void)
2566 {
2567 #ifdef UMA_DEBUG
2568 	printf("UMA: vm asked us to release pages!\n");
2569 #endif
2570 	bucket_enable();
2571 	zone_foreach(zone_drain);
2572 	/*
2573 	 * Some slabs may have been freed but this zone will be visited early
2574 	 * we visit again so that we can free pages that are empty once other
2575 	 * zones are drained.  We have to do the same for buckets.
2576 	 */
2577 	zone_drain(slabzone);
2578 	zone_drain(slabrefzone);
2579 	bucket_zone_drain();
2580 }
2581 
2582 void *
2583 uma_large_malloc(int size, int wait)
2584 {
2585 	void *mem;
2586 	uma_slab_t slab;
2587 	u_int8_t flags;
2588 
2589 	slab = uma_zalloc_internal(slabzone, NULL, wait);
2590 	if (slab == NULL)
2591 		return (NULL);
2592 	mem = page_alloc(NULL, size, &flags, wait);
2593 	if (mem) {
2594 		vsetslab((vm_offset_t)mem, slab);
2595 		slab->us_data = mem;
2596 		slab->us_flags = flags | UMA_SLAB_MALLOC;
2597 		slab->us_size = size;
2598 	} else {
2599 		uma_zfree_internal(slabzone, slab, NULL, 0);
2600 	}
2601 
2602 	return (mem);
2603 }
2604 
2605 void
2606 uma_large_free(uma_slab_t slab)
2607 {
2608 	vsetobj((vm_offset_t)slab->us_data, kmem_object);
2609 	page_free(slab->us_data, slab->us_size, slab->us_flags);
2610 	uma_zfree_internal(slabzone, slab, NULL, 0);
2611 }
2612 
2613 void
2614 uma_print_stats(void)
2615 {
2616 	zone_foreach(uma_print_zone);
2617 }
2618 
2619 static void
2620 slab_print(uma_slab_t slab)
2621 {
2622 	printf("slab: keg %p, data %p, freecount %d, firstfree %d\n",
2623 		slab->us_keg, slab->us_data, slab->us_freecount,
2624 		slab->us_firstfree);
2625 }
2626 
2627 static void
2628 cache_print(uma_cache_t cache)
2629 {
2630 	printf("alloc: %p(%d), free: %p(%d)\n",
2631 		cache->uc_allocbucket,
2632 		cache->uc_allocbucket?cache->uc_allocbucket->ub_cnt:0,
2633 		cache->uc_freebucket,
2634 		cache->uc_freebucket?cache->uc_freebucket->ub_cnt:0);
2635 }
2636 
2637 void
2638 uma_print_zone(uma_zone_t zone)
2639 {
2640 	uma_cache_t cache;
2641 	uma_keg_t keg;
2642 	uma_slab_t slab;
2643 	int i;
2644 
2645 	keg = zone->uz_keg;
2646 	printf("%s(%p) size %d(%d) flags %d ipers %d ppera %d out %d free %d\n",
2647 	    zone->uz_name, zone, keg->uk_size, keg->uk_rsize, keg->uk_flags,
2648 	    keg->uk_ipers, keg->uk_ppera,
2649 	    (keg->uk_ipers * keg->uk_pages) - keg->uk_free, keg->uk_free);
2650 	printf("Part slabs:\n");
2651 	LIST_FOREACH(slab, &keg->uk_part_slab, us_link)
2652 		slab_print(slab);
2653 	printf("Free slabs:\n");
2654 	LIST_FOREACH(slab, &keg->uk_free_slab, us_link)
2655 		slab_print(slab);
2656 	printf("Full slabs:\n");
2657 	LIST_FOREACH(slab, &keg->uk_full_slab, us_link)
2658 		slab_print(slab);
2659 	for (i = 0; i <= mp_maxid; i++) {
2660 		if (CPU_ABSENT(i))
2661 			continue;
2662 		cache = &zone->uz_cpu[i];
2663 		printf("CPU %d Cache:\n", i);
2664 		cache_print(cache);
2665 	}
2666 }
2667 
2668 /*
2669  * Sysctl handler for vm.zone
2670  *
2671  * stolen from vm_zone.c
2672  */
2673 static int
2674 sysctl_vm_zone(SYSCTL_HANDLER_ARGS)
2675 {
2676 	int error, len, cnt;
2677 	const int linesize = 128;	/* conservative */
2678 	int totalfree;
2679 	char *tmpbuf, *offset;
2680 	uma_zone_t z;
2681 	uma_keg_t zk;
2682 	char *p;
2683 	int cpu;
2684 	int cachefree;
2685 	uma_bucket_t bucket;
2686 	uma_cache_t cache;
2687 
2688 	cnt = 0;
2689 	mtx_lock(&uma_mtx);
2690 	LIST_FOREACH(zk, &uma_kegs, uk_link) {
2691 		LIST_FOREACH(z, &zk->uk_zones, uz_link)
2692 			cnt++;
2693 	}
2694 	mtx_unlock(&uma_mtx);
2695 	MALLOC(tmpbuf, char *, (cnt == 0 ? 1 : cnt) * linesize,
2696 			M_TEMP, M_WAITOK);
2697 	len = snprintf(tmpbuf, linesize,
2698 	    "\nITEM            SIZE     LIMIT     USED    FREE  REQUESTS\n\n");
2699 	if (cnt == 0)
2700 		tmpbuf[len - 1] = '\0';
2701 	error = SYSCTL_OUT(req, tmpbuf, cnt == 0 ? len-1 : len);
2702 	if (error || cnt == 0)
2703 		goto out;
2704 	offset = tmpbuf;
2705 	mtx_lock(&uma_mtx);
2706 	LIST_FOREACH(zk, &uma_kegs, uk_link) {
2707 	  LIST_FOREACH(z, &zk->uk_zones, uz_link) {
2708 		if (cnt == 0)	/* list may have changed size */
2709 			break;
2710 		if (!(zk->uk_flags & UMA_ZFLAG_INTERNAL)) {
2711 			for (cpu = 0; cpu <= mp_maxid; cpu++) {
2712 				if (CPU_ABSENT(cpu))
2713 					continue;
2714 				CPU_LOCK(cpu);
2715 			}
2716 		}
2717 		ZONE_LOCK(z);
2718 		cachefree = 0;
2719 		if (!(zk->uk_flags & UMA_ZFLAG_INTERNAL)) {
2720 			for (cpu = 0; cpu <= mp_maxid; cpu++) {
2721 				if (CPU_ABSENT(cpu))
2722 					continue;
2723 				cache = &z->uz_cpu[cpu];
2724 				if (cache->uc_allocbucket != NULL)
2725 					cachefree += cache->uc_allocbucket->ub_cnt;
2726 				if (cache->uc_freebucket != NULL)
2727 					cachefree += cache->uc_freebucket->ub_cnt;
2728 				CPU_UNLOCK(cpu);
2729 			}
2730 		}
2731 		LIST_FOREACH(bucket, &z->uz_full_bucket, ub_link) {
2732 			cachefree += bucket->ub_cnt;
2733 		}
2734 		totalfree = zk->uk_free + cachefree;
2735 		len = snprintf(offset, linesize,
2736 		    "%-12.12s  %6.6u, %8.8u, %6.6u, %6.6u, %8.8llu\n",
2737 		    z->uz_name, zk->uk_size,
2738 		    zk->uk_maxpages * zk->uk_ipers,
2739 		    (zk->uk_ipers * (zk->uk_pages / zk->uk_ppera)) - totalfree,
2740 		    totalfree,
2741 		    (unsigned long long)z->uz_allocs);
2742 		ZONE_UNLOCK(z);
2743 		for (p = offset + 12; p > offset && *p == ' '; --p)
2744 			/* nothing */ ;
2745 		p[1] = ':';
2746 		cnt--;
2747 		offset += len;
2748 	  }
2749 	}
2750 	mtx_unlock(&uma_mtx);
2751 	*offset++ = '\0';
2752 	error = SYSCTL_OUT(req, tmpbuf, offset - tmpbuf);
2753 out:
2754 	FREE(tmpbuf, M_TEMP);
2755 	return (error);
2756 }
2757