xref: /freebsd/sys/vm/uma_core.c (revision c96ae1968a6ab7056427a739bce81bf07447c2d4)
1 /*-
2  * Copyright (c) 2002, 2003, 2004, 2005 Jeffrey Roberson <jeff@FreeBSD.org>
3  * Copyright (c) 2004, 2005 Bosko Milekic <bmilekic@FreeBSD.org>
4  * Copyright (c) 2004-2006 Robert N. M. Watson
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 unmodified, this list of conditions, and the following
12  *    disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /*
30  * uma_core.c  Implementation of the Universal Memory allocator
31  *
32  * This allocator is intended to replace the multitude of similar object caches
33  * in the standard FreeBSD kernel.  The intent is to be flexible as well as
34  * effecient.  A primary design goal is to return unused memory to the rest of
35  * the system.  This will make the system as a whole more flexible due to the
36  * ability to move memory to subsystems which most need it instead of leaving
37  * pools of reserved memory unused.
38  *
39  * The basic ideas stem from similar slab/zone based allocators whose algorithms
40  * are well known.
41  *
42  */
43 
44 /*
45  * TODO:
46  *	- Improve memory usage for large allocations
47  *	- Investigate cache size adjustments
48  */
49 
50 #include <sys/cdefs.h>
51 __FBSDID("$FreeBSD$");
52 
53 /* I should really use ktr.. */
54 /*
55 #define UMA_DEBUG 1
56 #define UMA_DEBUG_ALLOC 1
57 #define UMA_DEBUG_ALLOC_1 1
58 */
59 
60 #include "opt_ddb.h"
61 #include "opt_param.h"
62 
63 #include <sys/param.h>
64 #include <sys/systm.h>
65 #include <sys/kernel.h>
66 #include <sys/types.h>
67 #include <sys/queue.h>
68 #include <sys/malloc.h>
69 #include <sys/ktr.h>
70 #include <sys/lock.h>
71 #include <sys/sysctl.h>
72 #include <sys/mutex.h>
73 #include <sys/proc.h>
74 #include <sys/sbuf.h>
75 #include <sys/smp.h>
76 #include <sys/vmmeter.h>
77 
78 #include <vm/vm.h>
79 #include <vm/vm_object.h>
80 #include <vm/vm_page.h>
81 #include <vm/vm_param.h>
82 #include <vm/vm_map.h>
83 #include <vm/vm_kern.h>
84 #include <vm/vm_extern.h>
85 #include <vm/uma.h>
86 #include <vm/uma_int.h>
87 #include <vm/uma_dbg.h>
88 
89 #include <machine/vmparam.h>
90 
91 #include <ddb/ddb.h>
92 
93 /*
94  * This is the zone and keg from which all zones are spawned.  The idea is that
95  * even the zone & keg heads are allocated from the allocator, so we use the
96  * bss section to bootstrap us.
97  */
98 static struct uma_keg masterkeg;
99 static struct uma_zone masterzone_k;
100 static struct uma_zone masterzone_z;
101 static uma_zone_t kegs = &masterzone_k;
102 static uma_zone_t zones = &masterzone_z;
103 
104 /* This is the zone from which all of uma_slab_t's are allocated. */
105 static uma_zone_t slabzone;
106 static uma_zone_t slabrefzone;	/* With refcounters (for UMA_ZONE_REFCNT) */
107 
108 /*
109  * The initial hash tables come out of this zone so they can be allocated
110  * prior to malloc coming up.
111  */
112 static uma_zone_t hashzone;
113 
114 static MALLOC_DEFINE(M_UMAHASH, "UMAHash", "UMA Hash Buckets");
115 
116 /*
117  * Are we allowed to allocate buckets?
118  */
119 static int bucketdisable = 1;
120 
121 /* Linked list of all kegs in the system */
122 static LIST_HEAD(,uma_keg) uma_kegs = LIST_HEAD_INITIALIZER(&uma_kegs);
123 
124 /* This mutex protects the keg list */
125 static struct mtx uma_mtx;
126 
127 /* Linked list of boot time pages */
128 static LIST_HEAD(,uma_slab) uma_boot_pages =
129     LIST_HEAD_INITIALIZER(&uma_boot_pages);
130 
131 /* This mutex protects the boot time pages list */
132 static struct mtx uma_boot_pages_mtx;
133 
134 /* Is the VM done starting up? */
135 static int booted = 0;
136 
137 /* Maximum number of allowed items-per-slab if the slab header is OFFPAGE */
138 static u_int uma_max_ipers;
139 static u_int uma_max_ipers_ref;
140 
141 /*
142  * This is the handle used to schedule events that need to happen
143  * outside of the allocation fast path.
144  */
145 static struct callout uma_callout;
146 #define	UMA_TIMEOUT	20		/* Seconds for callout interval. */
147 
148 /*
149  * This structure is passed as the zone ctor arg so that I don't have to create
150  * a special allocation function just for zones.
151  */
152 struct uma_zctor_args {
153 	char *name;
154 	size_t size;
155 	uma_ctor ctor;
156 	uma_dtor dtor;
157 	uma_init uminit;
158 	uma_fini fini;
159 	uma_keg_t keg;
160 	int align;
161 	u_int32_t flags;
162 };
163 
164 struct uma_kctor_args {
165 	uma_zone_t zone;
166 	size_t size;
167 	uma_init uminit;
168 	uma_fini fini;
169 	int align;
170 	u_int32_t flags;
171 };
172 
173 struct uma_bucket_zone {
174 	uma_zone_t	ubz_zone;
175 	char		*ubz_name;
176 	int		ubz_entries;
177 };
178 
179 #define	BUCKET_MAX	128
180 
181 struct uma_bucket_zone bucket_zones[] = {
182 	{ NULL, "16 Bucket", 16 },
183 	{ NULL, "32 Bucket", 32 },
184 	{ NULL, "64 Bucket", 64 },
185 	{ NULL, "128 Bucket", 128 },
186 	{ NULL, NULL, 0}
187 };
188 
189 #define	BUCKET_SHIFT	4
190 #define	BUCKET_ZONES	((BUCKET_MAX >> BUCKET_SHIFT) + 1)
191 
192 /*
193  * bucket_size[] maps requested bucket sizes to zones that allocate a bucket
194  * of approximately the right size.
195  */
196 static uint8_t bucket_size[BUCKET_ZONES];
197 
198 /*
199  * Flags and enumerations to be passed to internal functions.
200  */
201 enum zfreeskip { SKIP_NONE, SKIP_DTOR, SKIP_FINI };
202 
203 #define	ZFREE_STATFAIL	0x00000001	/* Update zone failure statistic. */
204 #define	ZFREE_STATFREE	0x00000002	/* Update zone free statistic. */
205 
206 /* Prototypes.. */
207 
208 static void *obj_alloc(uma_zone_t, int, u_int8_t *, int);
209 static void *page_alloc(uma_zone_t, int, u_int8_t *, int);
210 static void *startup_alloc(uma_zone_t, int, u_int8_t *, int);
211 static void page_free(void *, int, u_int8_t);
212 static uma_slab_t slab_zalloc(uma_zone_t, int);
213 static void cache_drain(uma_zone_t);
214 static void bucket_drain(uma_zone_t, uma_bucket_t);
215 static void bucket_cache_drain(uma_zone_t zone);
216 static int keg_ctor(void *, int, void *, int);
217 static void keg_dtor(void *, int, void *);
218 static int zone_ctor(void *, int, void *, int);
219 static void zone_dtor(void *, int, void *);
220 static int zero_init(void *, int, int);
221 static void zone_small_init(uma_zone_t zone);
222 static void zone_large_init(uma_zone_t zone);
223 static void zone_foreach(void (*zfunc)(uma_zone_t));
224 static void zone_timeout(uma_zone_t zone);
225 static int hash_alloc(struct uma_hash *);
226 static int hash_expand(struct uma_hash *, struct uma_hash *);
227 static void hash_free(struct uma_hash *hash);
228 static void uma_timeout(void *);
229 static void uma_startup3(void);
230 static void *uma_zalloc_internal(uma_zone_t, void *, int);
231 static void uma_zfree_internal(uma_zone_t, void *, void *, enum zfreeskip,
232     int);
233 static void bucket_enable(void);
234 static void bucket_init(void);
235 static uma_bucket_t bucket_alloc(int, int);
236 static void bucket_free(uma_bucket_t);
237 static void bucket_zone_drain(void);
238 static int uma_zalloc_bucket(uma_zone_t zone, int flags);
239 static uma_slab_t uma_zone_slab(uma_zone_t zone, int flags);
240 static void *uma_slab_alloc(uma_zone_t zone, uma_slab_t slab);
241 static uma_zone_t uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit,
242     uma_fini fini, int align, u_int32_t flags);
243 
244 void uma_print_zone(uma_zone_t);
245 void uma_print_stats(void);
246 static int sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS);
247 static int sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS);
248 
249 #ifdef WITNESS
250 static int nosleepwithlocks = 1;
251 #else
252 static int nosleepwithlocks = 0;
253 #endif
254 SYSCTL_INT(_debug, OID_AUTO, nosleepwithlocks, CTLFLAG_RW, &nosleepwithlocks,
255     0, "Convert M_WAITOK to M_NOWAIT to avoid lock-held-across-sleep paths");
256 SYSINIT(uma_startup3, SI_SUB_VM_CONF, SI_ORDER_SECOND, uma_startup3, NULL);
257 
258 SYSCTL_PROC(_vm, OID_AUTO, zone_count, CTLFLAG_RD|CTLTYPE_INT,
259     0, 0, sysctl_vm_zone_count, "I", "Number of UMA zones");
260 
261 SYSCTL_PROC(_vm, OID_AUTO, zone_stats, CTLFLAG_RD|CTLTYPE_STRUCT,
262     0, 0, sysctl_vm_zone_stats, "s,struct uma_type_header", "Zone Stats");
263 
264 /*
265  * This routine checks to see whether or not it's safe to enable buckets.
266  */
267 
268 static void
269 bucket_enable(void)
270 {
271 	if (cnt.v_free_count < cnt.v_free_min)
272 		bucketdisable = 1;
273 	else
274 		bucketdisable = 0;
275 }
276 
277 /*
278  * Initialize bucket_zones, the array of zones of buckets of various sizes.
279  *
280  * For each zone, calculate the memory required for each bucket, consisting
281  * of the header and an array of pointers.  Initialize bucket_size[] to point
282  * the range of appropriate bucket sizes at the zone.
283  */
284 static void
285 bucket_init(void)
286 {
287 	struct uma_bucket_zone *ubz;
288 	int i;
289 	int j;
290 
291 	for (i = 0, j = 0; bucket_zones[j].ubz_entries != 0; j++) {
292 		int size;
293 
294 		ubz = &bucket_zones[j];
295 		size = roundup(sizeof(struct uma_bucket), sizeof(void *));
296 		size += sizeof(void *) * ubz->ubz_entries;
297 		ubz->ubz_zone = uma_zcreate(ubz->ubz_name, size,
298 		    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
299 		for (; i <= ubz->ubz_entries; i += (1 << BUCKET_SHIFT))
300 			bucket_size[i >> BUCKET_SHIFT] = j;
301 	}
302 }
303 
304 /*
305  * Given a desired number of entries for a bucket, return the zone from which
306  * to allocate the bucket.
307  */
308 static struct uma_bucket_zone *
309 bucket_zone_lookup(int entries)
310 {
311 	int idx;
312 
313 	idx = howmany(entries, 1 << BUCKET_SHIFT);
314 	return (&bucket_zones[bucket_size[idx]]);
315 }
316 
317 static uma_bucket_t
318 bucket_alloc(int entries, int bflags)
319 {
320 	struct uma_bucket_zone *ubz;
321 	uma_bucket_t bucket;
322 
323 	/*
324 	 * This is to stop us from allocating per cpu buckets while we're
325 	 * running out of vm.boot_pages.  Otherwise, we would exhaust the
326 	 * boot pages.  This also prevents us from allocating buckets in
327 	 * low memory situations.
328 	 */
329 	if (bucketdisable)
330 		return (NULL);
331 
332 	ubz = bucket_zone_lookup(entries);
333 	bucket = uma_zalloc_internal(ubz->ubz_zone, NULL, bflags);
334 	if (bucket) {
335 #ifdef INVARIANTS
336 		bzero(bucket->ub_bucket, sizeof(void *) * ubz->ubz_entries);
337 #endif
338 		bucket->ub_cnt = 0;
339 		bucket->ub_entries = ubz->ubz_entries;
340 	}
341 
342 	return (bucket);
343 }
344 
345 static void
346 bucket_free(uma_bucket_t bucket)
347 {
348 	struct uma_bucket_zone *ubz;
349 
350 	ubz = bucket_zone_lookup(bucket->ub_entries);
351 	uma_zfree_internal(ubz->ubz_zone, bucket, NULL, SKIP_NONE,
352 	    ZFREE_STATFREE);
353 }
354 
355 static void
356 bucket_zone_drain(void)
357 {
358 	struct uma_bucket_zone *ubz;
359 
360 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
361 		zone_drain(ubz->ubz_zone);
362 }
363 
364 
365 /*
366  * Routine called by timeout which is used to fire off some time interval
367  * based calculations.  (stats, hash size, etc.)
368  *
369  * Arguments:
370  *	arg   Unused
371  *
372  * Returns:
373  *	Nothing
374  */
375 static void
376 uma_timeout(void *unused)
377 {
378 	bucket_enable();
379 	zone_foreach(zone_timeout);
380 
381 	/* Reschedule this event */
382 	callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
383 }
384 
385 /*
386  * Routine to perform timeout driven calculations.  This expands the
387  * hashes and does per cpu statistics aggregation.
388  *
389  *  Arguments:
390  *	zone  The zone to operate on
391  *
392  *  Returns:
393  *	Nothing
394  */
395 static void
396 zone_timeout(uma_zone_t zone)
397 {
398 	uma_keg_t keg;
399 	u_int64_t alloc;
400 
401 	keg = zone->uz_keg;
402 	alloc = 0;
403 
404 	/*
405 	 * Expand the zone hash table.
406 	 *
407 	 * This is done if the number of slabs is larger than the hash size.
408 	 * What I'm trying to do here is completely reduce collisions.  This
409 	 * may be a little aggressive.  Should I allow for two collisions max?
410 	 */
411 	ZONE_LOCK(zone);
412 	if (keg->uk_flags & UMA_ZONE_HASH &&
413 	    keg->uk_pages / keg->uk_ppera >= keg->uk_hash.uh_hashsize) {
414 		struct uma_hash newhash;
415 		struct uma_hash oldhash;
416 		int ret;
417 
418 		/*
419 		 * This is so involved because allocating and freeing
420 		 * while the zone lock is held will lead to deadlock.
421 		 * I have to do everything in stages and check for
422 		 * races.
423 		 */
424 		newhash = keg->uk_hash;
425 		ZONE_UNLOCK(zone);
426 		ret = hash_alloc(&newhash);
427 		ZONE_LOCK(zone);
428 		if (ret) {
429 			if (hash_expand(&keg->uk_hash, &newhash)) {
430 				oldhash = keg->uk_hash;
431 				keg->uk_hash = newhash;
432 			} else
433 				oldhash = newhash;
434 
435 			ZONE_UNLOCK(zone);
436 			hash_free(&oldhash);
437 			ZONE_LOCK(zone);
438 		}
439 	}
440 	ZONE_UNLOCK(zone);
441 }
442 
443 /*
444  * Allocate and zero fill the next sized hash table from the appropriate
445  * backing store.
446  *
447  * Arguments:
448  *	hash  A new hash structure with the old hash size in uh_hashsize
449  *
450  * Returns:
451  *	1 on sucess and 0 on failure.
452  */
453 static int
454 hash_alloc(struct uma_hash *hash)
455 {
456 	int oldsize;
457 	int alloc;
458 
459 	oldsize = hash->uh_hashsize;
460 
461 	/* We're just going to go to a power of two greater */
462 	if (oldsize)  {
463 		hash->uh_hashsize = oldsize * 2;
464 		alloc = sizeof(hash->uh_slab_hash[0]) * hash->uh_hashsize;
465 		hash->uh_slab_hash = (struct slabhead *)malloc(alloc,
466 		    M_UMAHASH, M_NOWAIT);
467 	} else {
468 		alloc = sizeof(hash->uh_slab_hash[0]) * UMA_HASH_SIZE_INIT;
469 		hash->uh_slab_hash = uma_zalloc_internal(hashzone, NULL,
470 		    M_WAITOK);
471 		hash->uh_hashsize = UMA_HASH_SIZE_INIT;
472 	}
473 	if (hash->uh_slab_hash) {
474 		bzero(hash->uh_slab_hash, alloc);
475 		hash->uh_hashmask = hash->uh_hashsize - 1;
476 		return (1);
477 	}
478 
479 	return (0);
480 }
481 
482 /*
483  * Expands the hash table for HASH zones.  This is done from zone_timeout
484  * to reduce collisions.  This must not be done in the regular allocation
485  * path, otherwise, we can recurse on the vm while allocating pages.
486  *
487  * Arguments:
488  *	oldhash  The hash you want to expand
489  *	newhash  The hash structure for the new table
490  *
491  * Returns:
492  *	Nothing
493  *
494  * Discussion:
495  */
496 static int
497 hash_expand(struct uma_hash *oldhash, struct uma_hash *newhash)
498 {
499 	uma_slab_t slab;
500 	int hval;
501 	int i;
502 
503 	if (!newhash->uh_slab_hash)
504 		return (0);
505 
506 	if (oldhash->uh_hashsize >= newhash->uh_hashsize)
507 		return (0);
508 
509 	/*
510 	 * I need to investigate hash algorithms for resizing without a
511 	 * full rehash.
512 	 */
513 
514 	for (i = 0; i < oldhash->uh_hashsize; i++)
515 		while (!SLIST_EMPTY(&oldhash->uh_slab_hash[i])) {
516 			slab = SLIST_FIRST(&oldhash->uh_slab_hash[i]);
517 			SLIST_REMOVE_HEAD(&oldhash->uh_slab_hash[i], us_hlink);
518 			hval = UMA_HASH(newhash, slab->us_data);
519 			SLIST_INSERT_HEAD(&newhash->uh_slab_hash[hval],
520 			    slab, us_hlink);
521 		}
522 
523 	return (1);
524 }
525 
526 /*
527  * Free the hash bucket to the appropriate backing store.
528  *
529  * Arguments:
530  *	slab_hash  The hash bucket we're freeing
531  *	hashsize   The number of entries in that hash bucket
532  *
533  * Returns:
534  *	Nothing
535  */
536 static void
537 hash_free(struct uma_hash *hash)
538 {
539 	if (hash->uh_slab_hash == NULL)
540 		return;
541 	if (hash->uh_hashsize == UMA_HASH_SIZE_INIT)
542 		uma_zfree_internal(hashzone,
543 		    hash->uh_slab_hash, NULL, SKIP_NONE, ZFREE_STATFREE);
544 	else
545 		free(hash->uh_slab_hash, M_UMAHASH);
546 }
547 
548 /*
549  * Frees all outstanding items in a bucket
550  *
551  * Arguments:
552  *	zone   The zone to free to, must be unlocked.
553  *	bucket The free/alloc bucket with items, cpu queue must be locked.
554  *
555  * Returns:
556  *	Nothing
557  */
558 
559 static void
560 bucket_drain(uma_zone_t zone, uma_bucket_t bucket)
561 {
562 	uma_slab_t slab;
563 	int mzone;
564 	void *item;
565 
566 	if (bucket == NULL)
567 		return;
568 
569 	slab = NULL;
570 	mzone = 0;
571 
572 	/* We have to lookup the slab again for malloc.. */
573 	if (zone->uz_keg->uk_flags & UMA_ZONE_MALLOC)
574 		mzone = 1;
575 
576 	while (bucket->ub_cnt > 0)  {
577 		bucket->ub_cnt--;
578 		item = bucket->ub_bucket[bucket->ub_cnt];
579 #ifdef INVARIANTS
580 		bucket->ub_bucket[bucket->ub_cnt] = NULL;
581 		KASSERT(item != NULL,
582 		    ("bucket_drain: botched ptr, item is NULL"));
583 #endif
584 		/*
585 		 * This is extremely inefficient.  The slab pointer was passed
586 		 * to uma_zfree_arg, but we lost it because the buckets don't
587 		 * hold them.  This will go away when free() gets a size passed
588 		 * to it.
589 		 */
590 		if (mzone)
591 			slab = vtoslab((vm_offset_t)item & (~UMA_SLAB_MASK));
592 		uma_zfree_internal(zone, item, slab, SKIP_DTOR, 0);
593 	}
594 }
595 
596 /*
597  * Drains the per cpu caches for a zone.
598  *
599  * NOTE: This may only be called while the zone is being turn down, and not
600  * during normal operation.  This is necessary in order that we do not have
601  * to migrate CPUs to drain the per-CPU caches.
602  *
603  * Arguments:
604  *	zone     The zone to drain, must be unlocked.
605  *
606  * Returns:
607  *	Nothing
608  */
609 static void
610 cache_drain(uma_zone_t zone)
611 {
612 	uma_cache_t cache;
613 	int cpu;
614 
615 	/*
616 	 * XXX: It is safe to not lock the per-CPU caches, because we're
617 	 * tearing down the zone anyway.  I.e., there will be no further use
618 	 * of the caches at this point.
619 	 *
620 	 * XXX: It would good to be able to assert that the zone is being
621 	 * torn down to prevent improper use of cache_drain().
622 	 *
623 	 * XXX: We lock the zone before passing into bucket_cache_drain() as
624 	 * it is used elsewhere.  Should the tear-down path be made special
625 	 * there in some form?
626 	 */
627 	for (cpu = 0; cpu <= mp_maxid; cpu++) {
628 		if (CPU_ABSENT(cpu))
629 			continue;
630 		cache = &zone->uz_cpu[cpu];
631 		bucket_drain(zone, cache->uc_allocbucket);
632 		bucket_drain(zone, cache->uc_freebucket);
633 		if (cache->uc_allocbucket != NULL)
634 			bucket_free(cache->uc_allocbucket);
635 		if (cache->uc_freebucket != NULL)
636 			bucket_free(cache->uc_freebucket);
637 		cache->uc_allocbucket = cache->uc_freebucket = NULL;
638 	}
639 	ZONE_LOCK(zone);
640 	bucket_cache_drain(zone);
641 	ZONE_UNLOCK(zone);
642 }
643 
644 /*
645  * Drain the cached buckets from a zone.  Expects a locked zone on entry.
646  */
647 static void
648 bucket_cache_drain(uma_zone_t zone)
649 {
650 	uma_bucket_t bucket;
651 
652 	/*
653 	 * Drain the bucket queues and free the buckets, we just keep two per
654 	 * cpu (alloc/free).
655 	 */
656 	while ((bucket = LIST_FIRST(&zone->uz_full_bucket)) != NULL) {
657 		LIST_REMOVE(bucket, ub_link);
658 		ZONE_UNLOCK(zone);
659 		bucket_drain(zone, bucket);
660 		bucket_free(bucket);
661 		ZONE_LOCK(zone);
662 	}
663 
664 	/* Now we do the free queue.. */
665 	while ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) {
666 		LIST_REMOVE(bucket, ub_link);
667 		bucket_free(bucket);
668 	}
669 }
670 
671 /*
672  * Frees pages from a zone back to the system.  This is done on demand from
673  * the pageout daemon.
674  *
675  * Arguments:
676  *	zone  The zone to free pages from
677  *	 all  Should we drain all items?
678  *
679  * Returns:
680  *	Nothing.
681  */
682 void
683 zone_drain(uma_zone_t zone)
684 {
685 	struct slabhead freeslabs = { 0 };
686 	uma_keg_t keg;
687 	uma_slab_t slab;
688 	uma_slab_t n;
689 	u_int8_t flags;
690 	u_int8_t *mem;
691 	int i;
692 
693 	keg = zone->uz_keg;
694 
695 	/*
696 	 * We don't want to take pages from statically allocated zones at this
697 	 * time
698 	 */
699 	if (keg->uk_flags & UMA_ZONE_NOFREE || keg->uk_freef == NULL)
700 		return;
701 
702 	ZONE_LOCK(zone);
703 
704 #ifdef UMA_DEBUG
705 	printf("%s free items: %u\n", zone->uz_name, keg->uk_free);
706 #endif
707 	bucket_cache_drain(zone);
708 	if (keg->uk_free == 0)
709 		goto finished;
710 
711 	slab = LIST_FIRST(&keg->uk_free_slab);
712 	while (slab) {
713 		n = LIST_NEXT(slab, us_link);
714 
715 		/* We have no where to free these to */
716 		if (slab->us_flags & UMA_SLAB_BOOT) {
717 			slab = n;
718 			continue;
719 		}
720 
721 		LIST_REMOVE(slab, us_link);
722 		keg->uk_pages -= keg->uk_ppera;
723 		keg->uk_free -= keg->uk_ipers;
724 
725 		if (keg->uk_flags & UMA_ZONE_HASH)
726 			UMA_HASH_REMOVE(&keg->uk_hash, slab, slab->us_data);
727 
728 		SLIST_INSERT_HEAD(&freeslabs, slab, us_hlink);
729 
730 		slab = n;
731 	}
732 finished:
733 	ZONE_UNLOCK(zone);
734 
735 	while ((slab = SLIST_FIRST(&freeslabs)) != NULL) {
736 		SLIST_REMOVE(&freeslabs, slab, uma_slab, us_hlink);
737 		if (keg->uk_fini)
738 			for (i = 0; i < keg->uk_ipers; i++)
739 				keg->uk_fini(
740 				    slab->us_data + (keg->uk_rsize * i),
741 				    keg->uk_size);
742 		flags = slab->us_flags;
743 		mem = slab->us_data;
744 
745 		if ((keg->uk_flags & UMA_ZONE_MALLOC) ||
746 		    (keg->uk_flags & UMA_ZONE_REFCNT)) {
747 			vm_object_t obj;
748 
749 			if (flags & UMA_SLAB_KMEM)
750 				obj = kmem_object;
751 			else
752 				obj = NULL;
753 			for (i = 0; i < keg->uk_ppera; i++)
754 				vsetobj((vm_offset_t)mem + (i * PAGE_SIZE),
755 				    obj);
756 		}
757 		if (keg->uk_flags & UMA_ZONE_OFFPAGE)
758 			uma_zfree_internal(keg->uk_slabzone, slab, NULL,
759 			    SKIP_NONE, ZFREE_STATFREE);
760 #ifdef UMA_DEBUG
761 		printf("%s: Returning %d bytes.\n",
762 		    zone->uz_name, UMA_SLAB_SIZE * keg->uk_ppera);
763 #endif
764 		keg->uk_freef(mem, UMA_SLAB_SIZE * keg->uk_ppera, flags);
765 	}
766 }
767 
768 /*
769  * Allocate a new slab for a zone.  This does not insert the slab onto a list.
770  *
771  * Arguments:
772  *	zone  The zone to allocate slabs for
773  *	wait  Shall we wait?
774  *
775  * Returns:
776  *	The slab that was allocated or NULL if there is no memory and the
777  *	caller specified M_NOWAIT.
778  */
779 static uma_slab_t
780 slab_zalloc(uma_zone_t zone, int wait)
781 {
782 	uma_slabrefcnt_t slabref;
783 	uma_slab_t slab;
784 	uma_keg_t keg;
785 	u_int8_t *mem;
786 	u_int8_t flags;
787 	int i;
788 
789 	slab = NULL;
790 	keg = zone->uz_keg;
791 
792 #ifdef UMA_DEBUG
793 	printf("slab_zalloc:  Allocating a new slab for %s\n", zone->uz_name);
794 #endif
795 	ZONE_UNLOCK(zone);
796 
797 	if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
798 		slab = uma_zalloc_internal(keg->uk_slabzone, NULL, wait);
799 		if (slab == NULL) {
800 			ZONE_LOCK(zone);
801 			return NULL;
802 		}
803 	}
804 
805 	/*
806 	 * This reproduces the old vm_zone behavior of zero filling pages the
807 	 * first time they are added to a zone.
808 	 *
809 	 * Malloced items are zeroed in uma_zalloc.
810 	 */
811 
812 	if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
813 		wait |= M_ZERO;
814 	else
815 		wait &= ~M_ZERO;
816 
817 	mem = keg->uk_allocf(zone, keg->uk_ppera * UMA_SLAB_SIZE,
818 	    &flags, wait);
819 	if (mem == NULL) {
820 		if (keg->uk_flags & UMA_ZONE_OFFPAGE)
821 			uma_zfree_internal(keg->uk_slabzone, slab, NULL,
822 			    SKIP_NONE, ZFREE_STATFREE);
823 		ZONE_LOCK(zone);
824 		return (NULL);
825 	}
826 
827 	/* Point the slab into the allocated memory */
828 	if (!(keg->uk_flags & UMA_ZONE_OFFPAGE))
829 		slab = (uma_slab_t )(mem + keg->uk_pgoff);
830 
831 	if ((keg->uk_flags & UMA_ZONE_MALLOC) ||
832 	    (keg->uk_flags & UMA_ZONE_REFCNT))
833 		for (i = 0; i < keg->uk_ppera; i++)
834 			vsetslab((vm_offset_t)mem + (i * PAGE_SIZE), slab);
835 
836 	slab->us_keg = keg;
837 	slab->us_data = mem;
838 	slab->us_freecount = keg->uk_ipers;
839 	slab->us_firstfree = 0;
840 	slab->us_flags = flags;
841 
842 	if (keg->uk_flags & UMA_ZONE_REFCNT) {
843 		slabref = (uma_slabrefcnt_t)slab;
844 		for (i = 0; i < keg->uk_ipers; i++) {
845 			slabref->us_freelist[i].us_refcnt = 0;
846 			slabref->us_freelist[i].us_item = i+1;
847 		}
848 	} else {
849 		for (i = 0; i < keg->uk_ipers; i++)
850 			slab->us_freelist[i].us_item = i+1;
851 	}
852 
853 	if (keg->uk_init != NULL) {
854 		for (i = 0; i < keg->uk_ipers; i++)
855 			if (keg->uk_init(slab->us_data + (keg->uk_rsize * i),
856 			    keg->uk_size, wait) != 0)
857 				break;
858 		if (i != keg->uk_ipers) {
859 			if (keg->uk_fini != NULL) {
860 				for (i--; i > -1; i--)
861 					keg->uk_fini(slab->us_data +
862 					    (keg->uk_rsize * i),
863 					    keg->uk_size);
864 			}
865 			if ((keg->uk_flags & UMA_ZONE_MALLOC) ||
866 			    (keg->uk_flags & UMA_ZONE_REFCNT)) {
867 				vm_object_t obj;
868 
869 				if (flags & UMA_SLAB_KMEM)
870 					obj = kmem_object;
871 				else
872 					obj = NULL;
873 				for (i = 0; i < keg->uk_ppera; i++)
874 					vsetobj((vm_offset_t)mem +
875 					    (i * PAGE_SIZE), obj);
876 			}
877 			if (keg->uk_flags & UMA_ZONE_OFFPAGE)
878 				uma_zfree_internal(keg->uk_slabzone, slab,
879 				    NULL, SKIP_NONE, ZFREE_STATFREE);
880 			keg->uk_freef(mem, UMA_SLAB_SIZE * keg->uk_ppera,
881 			    flags);
882 			ZONE_LOCK(zone);
883 			return (NULL);
884 		}
885 	}
886 	ZONE_LOCK(zone);
887 
888 	if (keg->uk_flags & UMA_ZONE_HASH)
889 		UMA_HASH_INSERT(&keg->uk_hash, slab, mem);
890 
891 	keg->uk_pages += keg->uk_ppera;
892 	keg->uk_free += keg->uk_ipers;
893 
894 	return (slab);
895 }
896 
897 /*
898  * This function is intended to be used early on in place of page_alloc() so
899  * that we may use the boot time page cache to satisfy allocations before
900  * the VM is ready.
901  */
902 static void *
903 startup_alloc(uma_zone_t zone, int bytes, u_int8_t *pflag, int wait)
904 {
905 	uma_keg_t keg;
906 	uma_slab_t tmps;
907 
908 	keg = zone->uz_keg;
909 
910 	/*
911 	 * Check our small startup cache to see if it has pages remaining.
912 	 */
913 	mtx_lock(&uma_boot_pages_mtx);
914 	if ((tmps = LIST_FIRST(&uma_boot_pages)) != NULL) {
915 		LIST_REMOVE(tmps, us_link);
916 		mtx_unlock(&uma_boot_pages_mtx);
917 		*pflag = tmps->us_flags;
918 		return (tmps->us_data);
919 	}
920 	mtx_unlock(&uma_boot_pages_mtx);
921 	if (booted == 0)
922 		panic("UMA: Increase vm.boot_pages");
923 	/*
924 	 * Now that we've booted reset these users to their real allocator.
925 	 */
926 #ifdef UMA_MD_SMALL_ALLOC
927 	keg->uk_allocf = uma_small_alloc;
928 #else
929 	keg->uk_allocf = page_alloc;
930 #endif
931 	return keg->uk_allocf(zone, bytes, pflag, wait);
932 }
933 
934 /*
935  * Allocates a number of pages from the system
936  *
937  * Arguments:
938  *	zone  Unused
939  *	bytes  The number of bytes requested
940  *	wait  Shall we wait?
941  *
942  * Returns:
943  *	A pointer to the alloced memory or possibly
944  *	NULL if M_NOWAIT is set.
945  */
946 static void *
947 page_alloc(uma_zone_t zone, int bytes, u_int8_t *pflag, int wait)
948 {
949 	void *p;	/* Returned page */
950 
951 	*pflag = UMA_SLAB_KMEM;
952 	p = (void *) kmem_malloc(kmem_map, bytes, wait);
953 
954 	return (p);
955 }
956 
957 /*
958  * Allocates a number of pages from within an object
959  *
960  * Arguments:
961  *	zone   Unused
962  *	bytes  The number of bytes requested
963  *	wait   Shall we wait?
964  *
965  * Returns:
966  *	A pointer to the alloced memory or possibly
967  *	NULL if M_NOWAIT is set.
968  */
969 static void *
970 obj_alloc(uma_zone_t zone, int bytes, u_int8_t *flags, int wait)
971 {
972 	vm_object_t object;
973 	vm_offset_t retkva, zkva;
974 	vm_page_t p;
975 	int pages, startpages;
976 
977 	object = zone->uz_keg->uk_obj;
978 	retkva = 0;
979 
980 	/*
981 	 * This looks a little weird since we're getting one page at a time.
982 	 */
983 	VM_OBJECT_LOCK(object);
984 	p = TAILQ_LAST(&object->memq, pglist);
985 	pages = p != NULL ? p->pindex + 1 : 0;
986 	startpages = pages;
987 	zkva = zone->uz_keg->uk_kva + pages * PAGE_SIZE;
988 	for (; bytes > 0; bytes -= PAGE_SIZE) {
989 		p = vm_page_alloc(object, pages,
990 		    VM_ALLOC_INTERRUPT | VM_ALLOC_WIRED);
991 		if (p == NULL) {
992 			if (pages != startpages)
993 				pmap_qremove(retkva, pages - startpages);
994 			while (pages != startpages) {
995 				pages--;
996 				p = TAILQ_LAST(&object->memq, pglist);
997 				vm_page_lock_queues();
998 				vm_page_unwire(p, 0);
999 				vm_page_free(p);
1000 				vm_page_unlock_queues();
1001 			}
1002 			retkva = 0;
1003 			goto done;
1004 		}
1005 		pmap_qenter(zkva, &p, 1);
1006 		if (retkva == 0)
1007 			retkva = zkva;
1008 		zkva += PAGE_SIZE;
1009 		pages += 1;
1010 	}
1011 done:
1012 	VM_OBJECT_UNLOCK(object);
1013 	*flags = UMA_SLAB_PRIV;
1014 
1015 	return ((void *)retkva);
1016 }
1017 
1018 /*
1019  * Frees a number of pages to the system
1020  *
1021  * Arguments:
1022  *	mem   A pointer to the memory to be freed
1023  *	size  The size of the memory being freed
1024  *	flags The original p->us_flags field
1025  *
1026  * Returns:
1027  *	Nothing
1028  */
1029 static void
1030 page_free(void *mem, int size, u_int8_t flags)
1031 {
1032 	vm_map_t map;
1033 
1034 	if (flags & UMA_SLAB_KMEM)
1035 		map = kmem_map;
1036 	else
1037 		panic("UMA: page_free used with invalid flags %d\n", flags);
1038 
1039 	kmem_free(map, (vm_offset_t)mem, size);
1040 }
1041 
1042 /*
1043  * Zero fill initializer
1044  *
1045  * Arguments/Returns follow uma_init specifications
1046  */
1047 static int
1048 zero_init(void *mem, int size, int flags)
1049 {
1050 	bzero(mem, size);
1051 	return (0);
1052 }
1053 
1054 /*
1055  * Finish creating a small uma zone.  This calculates ipers, and the zone size.
1056  *
1057  * Arguments
1058  *	zone  The zone we should initialize
1059  *
1060  * Returns
1061  *	Nothing
1062  */
1063 static void
1064 zone_small_init(uma_zone_t zone)
1065 {
1066 	uma_keg_t keg;
1067 	u_int rsize;
1068 	u_int memused;
1069 	u_int wastedspace;
1070 	u_int shsize;
1071 
1072 	keg = zone->uz_keg;
1073 	KASSERT(keg != NULL, ("Keg is null in zone_small_init"));
1074 	rsize = keg->uk_size;
1075 
1076 	if (rsize < UMA_SMALLEST_UNIT)
1077 		rsize = UMA_SMALLEST_UNIT;
1078 	if (rsize & keg->uk_align)
1079 		rsize = (rsize & ~keg->uk_align) + (keg->uk_align + 1);
1080 
1081 	keg->uk_rsize = rsize;
1082 	keg->uk_ppera = 1;
1083 
1084 	if (keg->uk_flags & UMA_ZONE_REFCNT) {
1085 		rsize += UMA_FRITMREF_SZ;	/* linkage & refcnt */
1086 		shsize = sizeof(struct uma_slab_refcnt);
1087 	} else {
1088 		rsize += UMA_FRITM_SZ;	/* Account for linkage */
1089 		shsize = sizeof(struct uma_slab);
1090 	}
1091 
1092 	keg->uk_ipers = (UMA_SLAB_SIZE - shsize) / rsize;
1093 	KASSERT(keg->uk_ipers != 0, ("zone_small_init: ipers is 0"));
1094 	memused = keg->uk_ipers * rsize + shsize;
1095 	wastedspace = UMA_SLAB_SIZE - memused;
1096 
1097 	/*
1098 	 * We can't do OFFPAGE if we're internal or if we've been
1099 	 * asked to not go to the VM for buckets.  If we do this we
1100 	 * may end up going to the VM (kmem_map) for slabs which we
1101 	 * do not want to do if we're UMA_ZFLAG_CACHEONLY as a
1102 	 * result of UMA_ZONE_VM, which clearly forbids it.
1103 	 */
1104 	if ((keg->uk_flags & UMA_ZFLAG_INTERNAL) ||
1105 	    (keg->uk_flags & UMA_ZFLAG_CACHEONLY))
1106 		return;
1107 
1108 	if ((wastedspace >= UMA_MAX_WASTE) &&
1109 	    (keg->uk_ipers < (UMA_SLAB_SIZE / keg->uk_rsize))) {
1110 		keg->uk_ipers = UMA_SLAB_SIZE / keg->uk_rsize;
1111 		KASSERT(keg->uk_ipers <= 255,
1112 		    ("zone_small_init: keg->uk_ipers too high!"));
1113 #ifdef UMA_DEBUG
1114 		printf("UMA decided we need offpage slab headers for "
1115 		    "zone: %s, calculated wastedspace = %d, "
1116 		    "maximum wasted space allowed = %d, "
1117 		    "calculated ipers = %d, "
1118 		    "new wasted space = %d\n", zone->uz_name, wastedspace,
1119 		    UMA_MAX_WASTE, keg->uk_ipers,
1120 		    UMA_SLAB_SIZE - keg->uk_ipers * keg->uk_rsize);
1121 #endif
1122 		keg->uk_flags |= UMA_ZONE_OFFPAGE;
1123 		if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
1124 			keg->uk_flags |= UMA_ZONE_HASH;
1125 	}
1126 }
1127 
1128 /*
1129  * Finish creating a large (> UMA_SLAB_SIZE) uma zone.  Just give in and do
1130  * OFFPAGE for now.  When I can allow for more dynamic slab sizes this will be
1131  * more complicated.
1132  *
1133  * Arguments
1134  *	zone  The zone we should initialize
1135  *
1136  * Returns
1137  *	Nothing
1138  */
1139 static void
1140 zone_large_init(uma_zone_t zone)
1141 {
1142 	uma_keg_t keg;
1143 	int pages;
1144 
1145 	keg = zone->uz_keg;
1146 
1147 	KASSERT(keg != NULL, ("Keg is null in zone_large_init"));
1148 	KASSERT((keg->uk_flags & UMA_ZFLAG_CACHEONLY) == 0,
1149 	    ("zone_large_init: Cannot large-init a UMA_ZFLAG_CACHEONLY zone"));
1150 
1151 	pages = keg->uk_size / UMA_SLAB_SIZE;
1152 
1153 	/* Account for remainder */
1154 	if ((pages * UMA_SLAB_SIZE) < keg->uk_size)
1155 		pages++;
1156 
1157 	keg->uk_ppera = pages;
1158 	keg->uk_ipers = 1;
1159 
1160 	keg->uk_flags |= UMA_ZONE_OFFPAGE;
1161 	if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
1162 		keg->uk_flags |= UMA_ZONE_HASH;
1163 
1164 	keg->uk_rsize = keg->uk_size;
1165 }
1166 
1167 /*
1168  * Keg header ctor.  This initializes all fields, locks, etc.  And inserts
1169  * the keg onto the global keg list.
1170  *
1171  * Arguments/Returns follow uma_ctor specifications
1172  *	udata  Actually uma_kctor_args
1173  */
1174 static int
1175 keg_ctor(void *mem, int size, void *udata, int flags)
1176 {
1177 	struct uma_kctor_args *arg = udata;
1178 	uma_keg_t keg = mem;
1179 	uma_zone_t zone;
1180 
1181 	bzero(keg, size);
1182 	keg->uk_size = arg->size;
1183 	keg->uk_init = arg->uminit;
1184 	keg->uk_fini = arg->fini;
1185 	keg->uk_align = arg->align;
1186 	keg->uk_free = 0;
1187 	keg->uk_pages = 0;
1188 	keg->uk_flags = arg->flags;
1189 	keg->uk_allocf = page_alloc;
1190 	keg->uk_freef = page_free;
1191 	keg->uk_recurse = 0;
1192 	keg->uk_slabzone = NULL;
1193 
1194 	/*
1195 	 * The master zone is passed to us at keg-creation time.
1196 	 */
1197 	zone = arg->zone;
1198 	zone->uz_keg = keg;
1199 
1200 	if (arg->flags & UMA_ZONE_VM)
1201 		keg->uk_flags |= UMA_ZFLAG_CACHEONLY;
1202 
1203 	if (arg->flags & UMA_ZONE_ZINIT)
1204 		keg->uk_init = zero_init;
1205 
1206 	/*
1207 	 * The +UMA_FRITM_SZ added to uk_size is to account for the
1208 	 * linkage that is added to the size in zone_small_init().  If
1209 	 * we don't account for this here then we may end up in
1210 	 * zone_small_init() with a calculated 'ipers' of 0.
1211 	 */
1212 	if (keg->uk_flags & UMA_ZONE_REFCNT) {
1213 		if ((keg->uk_size+UMA_FRITMREF_SZ) >
1214 		    (UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt)))
1215 			zone_large_init(zone);
1216 		else
1217 			zone_small_init(zone);
1218 	} else {
1219 		if ((keg->uk_size+UMA_FRITM_SZ) >
1220 		    (UMA_SLAB_SIZE - sizeof(struct uma_slab)))
1221 			zone_large_init(zone);
1222 		else
1223 			zone_small_init(zone);
1224 	}
1225 
1226 	if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
1227 		if (keg->uk_flags & UMA_ZONE_REFCNT)
1228 			keg->uk_slabzone = slabrefzone;
1229 		else
1230 			keg->uk_slabzone = slabzone;
1231 	}
1232 
1233 	/*
1234 	 * If we haven't booted yet we need allocations to go through the
1235 	 * startup cache until the vm is ready.
1236 	 */
1237 	if (keg->uk_ppera == 1) {
1238 #ifdef UMA_MD_SMALL_ALLOC
1239 		keg->uk_allocf = uma_small_alloc;
1240 		keg->uk_freef = uma_small_free;
1241 #endif
1242 		if (booted == 0)
1243 			keg->uk_allocf = startup_alloc;
1244 	}
1245 
1246 	/*
1247 	 * Initialize keg's lock (shared among zones) through
1248 	 * Master zone
1249 	 */
1250 	zone->uz_lock = &keg->uk_lock;
1251 	if (arg->flags & UMA_ZONE_MTXCLASS)
1252 		ZONE_LOCK_INIT(zone, 1);
1253 	else
1254 		ZONE_LOCK_INIT(zone, 0);
1255 
1256 	/*
1257 	 * If we're putting the slab header in the actual page we need to
1258 	 * figure out where in each page it goes.  This calculates a right
1259 	 * justified offset into the memory on an ALIGN_PTR boundary.
1260 	 */
1261 	if (!(keg->uk_flags & UMA_ZONE_OFFPAGE)) {
1262 		u_int totsize;
1263 
1264 		/* Size of the slab struct and free list */
1265 		if (keg->uk_flags & UMA_ZONE_REFCNT)
1266 			totsize = sizeof(struct uma_slab_refcnt) +
1267 			    keg->uk_ipers * UMA_FRITMREF_SZ;
1268 		else
1269 			totsize = sizeof(struct uma_slab) +
1270 			    keg->uk_ipers * UMA_FRITM_SZ;
1271 
1272 		if (totsize & UMA_ALIGN_PTR)
1273 			totsize = (totsize & ~UMA_ALIGN_PTR) +
1274 			    (UMA_ALIGN_PTR + 1);
1275 		keg->uk_pgoff = UMA_SLAB_SIZE - totsize;
1276 
1277 		if (keg->uk_flags & UMA_ZONE_REFCNT)
1278 			totsize = keg->uk_pgoff + sizeof(struct uma_slab_refcnt)
1279 			    + keg->uk_ipers * UMA_FRITMREF_SZ;
1280 		else
1281 			totsize = keg->uk_pgoff + sizeof(struct uma_slab)
1282 			    + keg->uk_ipers * UMA_FRITM_SZ;
1283 
1284 		/*
1285 		 * The only way the following is possible is if with our
1286 		 * UMA_ALIGN_PTR adjustments we are now bigger than
1287 		 * UMA_SLAB_SIZE.  I haven't checked whether this is
1288 		 * mathematically possible for all cases, so we make
1289 		 * sure here anyway.
1290 		 */
1291 		if (totsize > UMA_SLAB_SIZE) {
1292 			printf("zone %s ipers %d rsize %d size %d\n",
1293 			    zone->uz_name, keg->uk_ipers, keg->uk_rsize,
1294 			    keg->uk_size);
1295 			panic("UMA slab won't fit.\n");
1296 		}
1297 	}
1298 
1299 	if (keg->uk_flags & UMA_ZONE_HASH)
1300 		hash_alloc(&keg->uk_hash);
1301 
1302 #ifdef UMA_DEBUG
1303 	printf("%s(%p) size = %d ipers = %d ppera = %d pgoff = %d\n",
1304 	    zone->uz_name, zone,
1305 	    keg->uk_size, keg->uk_ipers,
1306 	    keg->uk_ppera, keg->uk_pgoff);
1307 #endif
1308 
1309 	LIST_INSERT_HEAD(&keg->uk_zones, zone, uz_link);
1310 
1311 	mtx_lock(&uma_mtx);
1312 	LIST_INSERT_HEAD(&uma_kegs, keg, uk_link);
1313 	mtx_unlock(&uma_mtx);
1314 	return (0);
1315 }
1316 
1317 /*
1318  * Zone header ctor.  This initializes all fields, locks, etc.
1319  *
1320  * Arguments/Returns follow uma_ctor specifications
1321  *	udata  Actually uma_zctor_args
1322  */
1323 
1324 static int
1325 zone_ctor(void *mem, int size, void *udata, int flags)
1326 {
1327 	struct uma_zctor_args *arg = udata;
1328 	uma_zone_t zone = mem;
1329 	uma_zone_t z;
1330 	uma_keg_t keg;
1331 
1332 	bzero(zone, size);
1333 	zone->uz_name = arg->name;
1334 	zone->uz_ctor = arg->ctor;
1335 	zone->uz_dtor = arg->dtor;
1336 	zone->uz_init = NULL;
1337 	zone->uz_fini = NULL;
1338 	zone->uz_allocs = 0;
1339 	zone->uz_frees = 0;
1340 	zone->uz_fails = 0;
1341 	zone->uz_fills = zone->uz_count = 0;
1342 
1343 	if (arg->flags & UMA_ZONE_SECONDARY) {
1344 		KASSERT(arg->keg != NULL, ("Secondary zone on zero'd keg"));
1345 		keg = arg->keg;
1346 		zone->uz_keg = keg;
1347 		zone->uz_init = arg->uminit;
1348 		zone->uz_fini = arg->fini;
1349 		zone->uz_lock = &keg->uk_lock;
1350 		mtx_lock(&uma_mtx);
1351 		ZONE_LOCK(zone);
1352 		keg->uk_flags |= UMA_ZONE_SECONDARY;
1353 		LIST_FOREACH(z, &keg->uk_zones, uz_link) {
1354 			if (LIST_NEXT(z, uz_link) == NULL) {
1355 				LIST_INSERT_AFTER(z, zone, uz_link);
1356 				break;
1357 			}
1358 		}
1359 		ZONE_UNLOCK(zone);
1360 		mtx_unlock(&uma_mtx);
1361 	} else if (arg->keg == NULL) {
1362 		if (uma_kcreate(zone, arg->size, arg->uminit, arg->fini,
1363 		    arg->align, arg->flags) == NULL)
1364 			return (ENOMEM);
1365 	} else {
1366 		struct uma_kctor_args karg;
1367 		int error;
1368 
1369 		/* We should only be here from uma_startup() */
1370 		karg.size = arg->size;
1371 		karg.uminit = arg->uminit;
1372 		karg.fini = arg->fini;
1373 		karg.align = arg->align;
1374 		karg.flags = arg->flags;
1375 		karg.zone = zone;
1376 		error = keg_ctor(arg->keg, sizeof(struct uma_keg), &karg,
1377 		    flags);
1378 		if (error)
1379 			return (error);
1380 	}
1381 	keg = zone->uz_keg;
1382 	zone->uz_lock = &keg->uk_lock;
1383 
1384 	/*
1385 	 * Some internal zones don't have room allocated for the per cpu
1386 	 * caches.  If we're internal, bail out here.
1387 	 */
1388 	if (keg->uk_flags & UMA_ZFLAG_INTERNAL) {
1389 		KASSERT((keg->uk_flags & UMA_ZONE_SECONDARY) == 0,
1390 		    ("Secondary zone requested UMA_ZFLAG_INTERNAL"));
1391 		return (0);
1392 	}
1393 
1394 	if (keg->uk_flags & UMA_ZONE_MAXBUCKET)
1395 		zone->uz_count = BUCKET_MAX;
1396 	else if (keg->uk_ipers <= BUCKET_MAX)
1397 		zone->uz_count = keg->uk_ipers;
1398 	else
1399 		zone->uz_count = BUCKET_MAX;
1400 	return (0);
1401 }
1402 
1403 /*
1404  * Keg header dtor.  This frees all data, destroys locks, frees the hash
1405  * table and removes the keg from the global list.
1406  *
1407  * Arguments/Returns follow uma_dtor specifications
1408  *	udata  unused
1409  */
1410 static void
1411 keg_dtor(void *arg, int size, void *udata)
1412 {
1413 	uma_keg_t keg;
1414 
1415 	keg = (uma_keg_t)arg;
1416 	mtx_lock(&keg->uk_lock);
1417 	if (keg->uk_free != 0) {
1418 		printf("Freed UMA keg was not empty (%d items). "
1419 		    " Lost %d pages of memory.\n",
1420 		    keg->uk_free, keg->uk_pages);
1421 	}
1422 	mtx_unlock(&keg->uk_lock);
1423 
1424 	if (keg->uk_flags & UMA_ZONE_HASH)
1425 		hash_free(&keg->uk_hash);
1426 
1427 	mtx_destroy(&keg->uk_lock);
1428 }
1429 
1430 /*
1431  * Zone header dtor.
1432  *
1433  * Arguments/Returns follow uma_dtor specifications
1434  *	udata  unused
1435  */
1436 static void
1437 zone_dtor(void *arg, int size, void *udata)
1438 {
1439 	uma_zone_t zone;
1440 	uma_keg_t keg;
1441 
1442 	zone = (uma_zone_t)arg;
1443 	keg = zone->uz_keg;
1444 
1445 	if (!(keg->uk_flags & UMA_ZFLAG_INTERNAL))
1446 		cache_drain(zone);
1447 
1448 	mtx_lock(&uma_mtx);
1449 	zone_drain(zone);
1450 	if (keg->uk_flags & UMA_ZONE_SECONDARY) {
1451 		LIST_REMOVE(zone, uz_link);
1452 		/*
1453 		 * XXX there are some races here where
1454 		 * the zone can be drained but zone lock
1455 		 * released and then refilled before we
1456 		 * remove it... we dont care for now
1457 		 */
1458 		ZONE_LOCK(zone);
1459 		if (LIST_EMPTY(&keg->uk_zones))
1460 			keg->uk_flags &= ~UMA_ZONE_SECONDARY;
1461 		ZONE_UNLOCK(zone);
1462 		mtx_unlock(&uma_mtx);
1463 	} else {
1464 		LIST_REMOVE(keg, uk_link);
1465 		LIST_REMOVE(zone, uz_link);
1466 		mtx_unlock(&uma_mtx);
1467 		uma_zfree_internal(kegs, keg, NULL, SKIP_NONE,
1468 		    ZFREE_STATFREE);
1469 	}
1470 	zone->uz_keg = NULL;
1471 }
1472 
1473 /*
1474  * Traverses every zone in the system and calls a callback
1475  *
1476  * Arguments:
1477  *	zfunc  A pointer to a function which accepts a zone
1478  *		as an argument.
1479  *
1480  * Returns:
1481  *	Nothing
1482  */
1483 static void
1484 zone_foreach(void (*zfunc)(uma_zone_t))
1485 {
1486 	uma_keg_t keg;
1487 	uma_zone_t zone;
1488 
1489 	mtx_lock(&uma_mtx);
1490 	LIST_FOREACH(keg, &uma_kegs, uk_link) {
1491 		LIST_FOREACH(zone, &keg->uk_zones, uz_link)
1492 			zfunc(zone);
1493 	}
1494 	mtx_unlock(&uma_mtx);
1495 }
1496 
1497 /* Public functions */
1498 /* See uma.h */
1499 void
1500 uma_startup(void *bootmem, int boot_pages)
1501 {
1502 	struct uma_zctor_args args;
1503 	uma_slab_t slab;
1504 	u_int slabsize;
1505 	u_int objsize, totsize, wsize;
1506 	int i;
1507 
1508 #ifdef UMA_DEBUG
1509 	printf("Creating uma keg headers zone and keg.\n");
1510 #endif
1511 	mtx_init(&uma_mtx, "UMA lock", NULL, MTX_DEF);
1512 
1513 	/*
1514 	 * Figure out the maximum number of items-per-slab we'll have if
1515 	 * we're using the OFFPAGE slab header to track free items, given
1516 	 * all possible object sizes and the maximum desired wastage
1517 	 * (UMA_MAX_WASTE).
1518 	 *
1519 	 * We iterate until we find an object size for
1520 	 * which the calculated wastage in zone_small_init() will be
1521 	 * enough to warrant OFFPAGE.  Since wastedspace versus objsize
1522 	 * is an overall increasing see-saw function, we find the smallest
1523 	 * objsize such that the wastage is always acceptable for objects
1524 	 * with that objsize or smaller.  Since a smaller objsize always
1525 	 * generates a larger possible uma_max_ipers, we use this computed
1526 	 * objsize to calculate the largest ipers possible.  Since the
1527 	 * ipers calculated for OFFPAGE slab headers is always larger than
1528 	 * the ipers initially calculated in zone_small_init(), we use
1529 	 * the former's equation (UMA_SLAB_SIZE / keg->uk_rsize) to
1530 	 * obtain the maximum ipers possible for offpage slab headers.
1531 	 *
1532 	 * It should be noted that ipers versus objsize is an inversly
1533 	 * proportional function which drops off rather quickly so as
1534 	 * long as our UMA_MAX_WASTE is such that the objsize we calculate
1535 	 * falls into the portion of the inverse relation AFTER the steep
1536 	 * falloff, then uma_max_ipers shouldn't be too high (~10 on i386).
1537 	 *
1538 	 * Note that we have 8-bits (1 byte) to use as a freelist index
1539 	 * inside the actual slab header itself and this is enough to
1540 	 * accomodate us.  In the worst case, a UMA_SMALLEST_UNIT sized
1541 	 * object with offpage slab header would have ipers =
1542 	 * UMA_SLAB_SIZE / UMA_SMALLEST_UNIT (currently = 256), which is
1543 	 * 1 greater than what our byte-integer freelist index can
1544 	 * accomodate, but we know that this situation never occurs as
1545 	 * for UMA_SMALLEST_UNIT-sized objects, we will never calculate
1546 	 * that we need to go to offpage slab headers.  Or, if we do,
1547 	 * then we trap that condition below and panic in the INVARIANTS case.
1548 	 */
1549 	wsize = UMA_SLAB_SIZE - sizeof(struct uma_slab) - UMA_MAX_WASTE;
1550 	totsize = wsize;
1551 	objsize = UMA_SMALLEST_UNIT;
1552 	while (totsize >= wsize) {
1553 		totsize = (UMA_SLAB_SIZE - sizeof(struct uma_slab)) /
1554 		    (objsize + UMA_FRITM_SZ);
1555 		totsize *= (UMA_FRITM_SZ + objsize);
1556 		objsize++;
1557 	}
1558 	if (objsize > UMA_SMALLEST_UNIT)
1559 		objsize--;
1560 	uma_max_ipers = UMA_SLAB_SIZE / objsize;
1561 
1562 	wsize = UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt) - UMA_MAX_WASTE;
1563 	totsize = wsize;
1564 	objsize = UMA_SMALLEST_UNIT;
1565 	while (totsize >= wsize) {
1566 		totsize = (UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt)) /
1567 		    (objsize + UMA_FRITMREF_SZ);
1568 		totsize *= (UMA_FRITMREF_SZ + objsize);
1569 		objsize++;
1570 	}
1571 	if (objsize > UMA_SMALLEST_UNIT)
1572 		objsize--;
1573 	uma_max_ipers_ref = UMA_SLAB_SIZE / objsize;
1574 
1575 	KASSERT((uma_max_ipers_ref <= 255) && (uma_max_ipers <= 255),
1576 	    ("uma_startup: calculated uma_max_ipers values too large!"));
1577 
1578 #ifdef UMA_DEBUG
1579 	printf("Calculated uma_max_ipers (for OFFPAGE) is %d\n", uma_max_ipers);
1580 	printf("Calculated uma_max_ipers_slab (for OFFPAGE) is %d\n",
1581 	    uma_max_ipers_ref);
1582 #endif
1583 
1584 	/* "manually" create the initial zone */
1585 	args.name = "UMA Kegs";
1586 	args.size = sizeof(struct uma_keg);
1587 	args.ctor = keg_ctor;
1588 	args.dtor = keg_dtor;
1589 	args.uminit = zero_init;
1590 	args.fini = NULL;
1591 	args.keg = &masterkeg;
1592 	args.align = 32 - 1;
1593 	args.flags = UMA_ZFLAG_INTERNAL;
1594 	/* The initial zone has no Per cpu queues so it's smaller */
1595 	zone_ctor(kegs, sizeof(struct uma_zone), &args, M_WAITOK);
1596 
1597 #ifdef UMA_DEBUG
1598 	printf("Filling boot free list.\n");
1599 #endif
1600 	for (i = 0; i < boot_pages; i++) {
1601 		slab = (uma_slab_t)((u_int8_t *)bootmem + (i * UMA_SLAB_SIZE));
1602 		slab->us_data = (u_int8_t *)slab;
1603 		slab->us_flags = UMA_SLAB_BOOT;
1604 		LIST_INSERT_HEAD(&uma_boot_pages, slab, us_link);
1605 	}
1606 	mtx_init(&uma_boot_pages_mtx, "UMA boot pages", NULL, MTX_DEF);
1607 
1608 #ifdef UMA_DEBUG
1609 	printf("Creating uma zone headers zone and keg.\n");
1610 #endif
1611 	args.name = "UMA Zones";
1612 	args.size = sizeof(struct uma_zone) +
1613 	    (sizeof(struct uma_cache) * (mp_maxid + 1));
1614 	args.ctor = zone_ctor;
1615 	args.dtor = zone_dtor;
1616 	args.uminit = zero_init;
1617 	args.fini = NULL;
1618 	args.keg = NULL;
1619 	args.align = 32 - 1;
1620 	args.flags = UMA_ZFLAG_INTERNAL;
1621 	/* The initial zone has no Per cpu queues so it's smaller */
1622 	zone_ctor(zones, sizeof(struct uma_zone), &args, M_WAITOK);
1623 
1624 #ifdef UMA_DEBUG
1625 	printf("Initializing pcpu cache locks.\n");
1626 #endif
1627 #ifdef UMA_DEBUG
1628 	printf("Creating slab and hash zones.\n");
1629 #endif
1630 
1631 	/*
1632 	 * This is the max number of free list items we'll have with
1633 	 * offpage slabs.
1634 	 */
1635 	slabsize = uma_max_ipers * UMA_FRITM_SZ;
1636 	slabsize += sizeof(struct uma_slab);
1637 
1638 	/* Now make a zone for slab headers */
1639 	slabzone = uma_zcreate("UMA Slabs",
1640 				slabsize,
1641 				NULL, NULL, NULL, NULL,
1642 				UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
1643 
1644 	/*
1645 	 * We also create a zone for the bigger slabs with reference
1646 	 * counts in them, to accomodate UMA_ZONE_REFCNT zones.
1647 	 */
1648 	slabsize = uma_max_ipers_ref * UMA_FRITMREF_SZ;
1649 	slabsize += sizeof(struct uma_slab_refcnt);
1650 	slabrefzone = uma_zcreate("UMA RCntSlabs",
1651 				  slabsize,
1652 				  NULL, NULL, NULL, NULL,
1653 				  UMA_ALIGN_PTR,
1654 				  UMA_ZFLAG_INTERNAL);
1655 
1656 	hashzone = uma_zcreate("UMA Hash",
1657 	    sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT,
1658 	    NULL, NULL, NULL, NULL,
1659 	    UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
1660 
1661 	bucket_init();
1662 
1663 #ifdef UMA_MD_SMALL_ALLOC
1664 	booted = 1;
1665 #endif
1666 
1667 #ifdef UMA_DEBUG
1668 	printf("UMA startup complete.\n");
1669 #endif
1670 }
1671 
1672 /* see uma.h */
1673 void
1674 uma_startup2(void)
1675 {
1676 	booted = 1;
1677 	bucket_enable();
1678 #ifdef UMA_DEBUG
1679 	printf("UMA startup2 complete.\n");
1680 #endif
1681 }
1682 
1683 /*
1684  * Initialize our callout handle
1685  *
1686  */
1687 
1688 static void
1689 uma_startup3(void)
1690 {
1691 #ifdef UMA_DEBUG
1692 	printf("Starting callout.\n");
1693 #endif
1694 	callout_init(&uma_callout, CALLOUT_MPSAFE);
1695 	callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
1696 #ifdef UMA_DEBUG
1697 	printf("UMA startup3 complete.\n");
1698 #endif
1699 }
1700 
1701 static uma_zone_t
1702 uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini,
1703 		int align, u_int32_t flags)
1704 {
1705 	struct uma_kctor_args args;
1706 
1707 	args.size = size;
1708 	args.uminit = uminit;
1709 	args.fini = fini;
1710 	args.align = align;
1711 	args.flags = flags;
1712 	args.zone = zone;
1713 	return (uma_zalloc_internal(kegs, &args, M_WAITOK));
1714 }
1715 
1716 /* See uma.h */
1717 uma_zone_t
1718 uma_zcreate(char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
1719 		uma_init uminit, uma_fini fini, int align, u_int32_t flags)
1720 
1721 {
1722 	struct uma_zctor_args args;
1723 
1724 	/* This stuff is essential for the zone ctor */
1725 	args.name = name;
1726 	args.size = size;
1727 	args.ctor = ctor;
1728 	args.dtor = dtor;
1729 	args.uminit = uminit;
1730 	args.fini = fini;
1731 	args.align = align;
1732 	args.flags = flags;
1733 	args.keg = NULL;
1734 
1735 	return (uma_zalloc_internal(zones, &args, M_WAITOK));
1736 }
1737 
1738 /* See uma.h */
1739 uma_zone_t
1740 uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
1741 		    uma_init zinit, uma_fini zfini, uma_zone_t master)
1742 {
1743 	struct uma_zctor_args args;
1744 
1745 	args.name = name;
1746 	args.size = master->uz_keg->uk_size;
1747 	args.ctor = ctor;
1748 	args.dtor = dtor;
1749 	args.uminit = zinit;
1750 	args.fini = zfini;
1751 	args.align = master->uz_keg->uk_align;
1752 	args.flags = master->uz_keg->uk_flags | UMA_ZONE_SECONDARY;
1753 	args.keg = master->uz_keg;
1754 
1755 	return (uma_zalloc_internal(zones, &args, M_WAITOK));
1756 }
1757 
1758 /* See uma.h */
1759 void
1760 uma_zdestroy(uma_zone_t zone)
1761 {
1762 
1763 	uma_zfree_internal(zones, zone, NULL, SKIP_NONE, ZFREE_STATFREE);
1764 }
1765 
1766 /* See uma.h */
1767 void *
1768 uma_zalloc_arg(uma_zone_t zone, void *udata, int flags)
1769 {
1770 	void *item;
1771 	uma_cache_t cache;
1772 	uma_bucket_t bucket;
1773 	int cpu;
1774 
1775 	/* This is the fast path allocation */
1776 #ifdef UMA_DEBUG_ALLOC_1
1777 	printf("Allocating one item from %s(%p)\n", zone->uz_name, zone);
1778 #endif
1779 	CTR3(KTR_UMA, "uma_zalloc_arg thread %x zone %s flags %d", curthread,
1780 	    zone->uz_name, flags);
1781 
1782 	if (flags & M_WAITOK) {
1783 		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
1784 		    "uma_zalloc_arg: zone \"%s\"", zone->uz_name);
1785 	}
1786 
1787 	/*
1788 	 * If possible, allocate from the per-CPU cache.  There are two
1789 	 * requirements for safe access to the per-CPU cache: (1) the thread
1790 	 * accessing the cache must not be preempted or yield during access,
1791 	 * and (2) the thread must not migrate CPUs without switching which
1792 	 * cache it accesses.  We rely on a critical section to prevent
1793 	 * preemption and migration.  We release the critical section in
1794 	 * order to acquire the zone mutex if we are unable to allocate from
1795 	 * the current cache; when we re-acquire the critical section, we
1796 	 * must detect and handle migration if it has occurred.
1797 	 */
1798 zalloc_restart:
1799 	critical_enter();
1800 	cpu = curcpu;
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 			critical_exit();
1817 #ifdef INVARIANTS
1818 			ZONE_LOCK(zone);
1819 			uma_dbg_alloc(zone, NULL, item);
1820 			ZONE_UNLOCK(zone);
1821 #endif
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, ZFREE_STATFAIL |
1827 					    ZFREE_STATFREE);
1828 					return (NULL);
1829 				}
1830 			}
1831 			if (flags & M_ZERO)
1832 				bzero(item, zone->uz_keg->uk_size);
1833 			return (item);
1834 		} else if (cache->uc_freebucket) {
1835 			/*
1836 			 * We have run out of items in our allocbucket.
1837 			 * See if we can switch with our free bucket.
1838 			 */
1839 			if (cache->uc_freebucket->ub_cnt > 0) {
1840 #ifdef UMA_DEBUG_ALLOC
1841 				printf("uma_zalloc: Swapping empty with"
1842 				    " alloc.\n");
1843 #endif
1844 				bucket = cache->uc_freebucket;
1845 				cache->uc_freebucket = cache->uc_allocbucket;
1846 				cache->uc_allocbucket = bucket;
1847 
1848 				goto zalloc_start;
1849 			}
1850 		}
1851 	}
1852 	/*
1853 	 * Attempt to retrieve the item from the per-CPU cache has failed, so
1854 	 * we must go back to the zone.  This requires the zone lock, so we
1855 	 * must drop the critical section, then re-acquire it when we go back
1856 	 * to the cache.  Since the critical section is released, we may be
1857 	 * preempted or migrate.  As such, make sure not to maintain any
1858 	 * thread-local state specific to the cache from prior to releasing
1859 	 * the critical section.
1860 	 */
1861 	critical_exit();
1862 	ZONE_LOCK(zone);
1863 	critical_enter();
1864 	cpu = curcpu;
1865 	cache = &zone->uz_cpu[cpu];
1866 	bucket = cache->uc_allocbucket;
1867 	if (bucket != NULL) {
1868 		if (bucket->ub_cnt > 0) {
1869 			ZONE_UNLOCK(zone);
1870 			goto zalloc_start;
1871 		}
1872 		bucket = cache->uc_freebucket;
1873 		if (bucket != NULL && bucket->ub_cnt > 0) {
1874 			ZONE_UNLOCK(zone);
1875 			goto zalloc_start;
1876 		}
1877 	}
1878 
1879 	/* Since we have locked the zone we may as well send back our stats */
1880 	zone->uz_allocs += cache->uc_allocs;
1881 	cache->uc_allocs = 0;
1882 	zone->uz_frees += cache->uc_frees;
1883 	cache->uc_frees = 0;
1884 
1885 	/* Our old one is now a free bucket */
1886 	if (cache->uc_allocbucket) {
1887 		KASSERT(cache->uc_allocbucket->ub_cnt == 0,
1888 		    ("uma_zalloc_arg: Freeing a non free bucket."));
1889 		LIST_INSERT_HEAD(&zone->uz_free_bucket,
1890 		    cache->uc_allocbucket, ub_link);
1891 		cache->uc_allocbucket = NULL;
1892 	}
1893 
1894 	/* Check the free list for a new alloc bucket */
1895 	if ((bucket = LIST_FIRST(&zone->uz_full_bucket)) != NULL) {
1896 		KASSERT(bucket->ub_cnt != 0,
1897 		    ("uma_zalloc_arg: Returning an empty bucket."));
1898 
1899 		LIST_REMOVE(bucket, ub_link);
1900 		cache->uc_allocbucket = bucket;
1901 		ZONE_UNLOCK(zone);
1902 		goto zalloc_start;
1903 	}
1904 	/* We are no longer associated with this CPU. */
1905 	critical_exit();
1906 
1907 	/* Bump up our uz_count so we get here less */
1908 	if (zone->uz_count < BUCKET_MAX)
1909 		zone->uz_count++;
1910 
1911 	/*
1912 	 * Now lets just fill a bucket and put it on the free list.  If that
1913 	 * works we'll restart the allocation from the begining.
1914 	 */
1915 	if (uma_zalloc_bucket(zone, flags)) {
1916 		ZONE_UNLOCK(zone);
1917 		goto zalloc_restart;
1918 	}
1919 	ZONE_UNLOCK(zone);
1920 	/*
1921 	 * We may not be able to get a bucket so return an actual item.
1922 	 */
1923 #ifdef UMA_DEBUG
1924 	printf("uma_zalloc_arg: Bucketzone returned NULL\n");
1925 #endif
1926 
1927 	return (uma_zalloc_internal(zone, udata, flags));
1928 }
1929 
1930 static uma_slab_t
1931 uma_zone_slab(uma_zone_t zone, int flags)
1932 {
1933 	uma_slab_t slab;
1934 	uma_keg_t keg;
1935 
1936 	keg = zone->uz_keg;
1937 
1938 	/*
1939 	 * This is to prevent us from recursively trying to allocate
1940 	 * buckets.  The problem is that if an allocation forces us to
1941 	 * grab a new bucket we will call page_alloc, which will go off
1942 	 * and cause the vm to allocate vm_map_entries.  If we need new
1943 	 * buckets there too we will recurse in kmem_alloc and bad
1944 	 * things happen.  So instead we return a NULL bucket, and make
1945 	 * the code that allocates buckets smart enough to deal with it
1946 	 *
1947 	 * XXX: While we want this protection for the bucket zones so that
1948 	 * recursion from the VM is handled (and the calling code that
1949 	 * allocates buckets knows how to deal with it), we do not want
1950 	 * to prevent allocation from the slab header zones (slabzone
1951 	 * and slabrefzone) if uk_recurse is not zero for them.  The
1952 	 * reason is that it could lead to NULL being returned for
1953 	 * slab header allocations even in the M_WAITOK case, and the
1954 	 * caller can't handle that.
1955 	 */
1956 	if (keg->uk_flags & UMA_ZFLAG_INTERNAL && keg->uk_recurse != 0)
1957 		if ((zone != slabzone) && (zone != slabrefzone))
1958 			return (NULL);
1959 
1960 	slab = NULL;
1961 
1962 	for (;;) {
1963 		/*
1964 		 * Find a slab with some space.  Prefer slabs that are partially
1965 		 * used over those that are totally full.  This helps to reduce
1966 		 * fragmentation.
1967 		 */
1968 		if (keg->uk_free != 0) {
1969 			if (!LIST_EMPTY(&keg->uk_part_slab)) {
1970 				slab = LIST_FIRST(&keg->uk_part_slab);
1971 			} else {
1972 				slab = LIST_FIRST(&keg->uk_free_slab);
1973 				LIST_REMOVE(slab, us_link);
1974 				LIST_INSERT_HEAD(&keg->uk_part_slab, slab,
1975 				    us_link);
1976 			}
1977 			return (slab);
1978 		}
1979 
1980 		/*
1981 		 * M_NOVM means don't ask at all!
1982 		 */
1983 		if (flags & M_NOVM)
1984 			break;
1985 
1986 		if (keg->uk_maxpages &&
1987 		    keg->uk_pages >= keg->uk_maxpages) {
1988 			keg->uk_flags |= UMA_ZFLAG_FULL;
1989 
1990 			if (flags & M_NOWAIT)
1991 				break;
1992 			else
1993 				msleep(keg, &keg->uk_lock, PVM,
1994 				    "zonelimit", 0);
1995 			continue;
1996 		}
1997 		keg->uk_recurse++;
1998 		slab = slab_zalloc(zone, flags);
1999 		keg->uk_recurse--;
2000 
2001 		/*
2002 		 * If we got a slab here it's safe to mark it partially used
2003 		 * and return.  We assume that the caller is going to remove
2004 		 * at least one item.
2005 		 */
2006 		if (slab) {
2007 			LIST_INSERT_HEAD(&keg->uk_part_slab, slab, us_link);
2008 			return (slab);
2009 		}
2010 		/*
2011 		 * We might not have been able to get a slab but another cpu
2012 		 * could have while we were unlocked.  Check again before we
2013 		 * fail.
2014 		 */
2015 		if (flags & M_NOWAIT)
2016 			flags |= M_NOVM;
2017 	}
2018 	return (slab);
2019 }
2020 
2021 static void *
2022 uma_slab_alloc(uma_zone_t zone, uma_slab_t slab)
2023 {
2024 	uma_keg_t keg;
2025 	uma_slabrefcnt_t slabref;
2026 	void *item;
2027 	u_int8_t freei;
2028 
2029 	keg = zone->uz_keg;
2030 
2031 	freei = slab->us_firstfree;
2032 	if (keg->uk_flags & UMA_ZONE_REFCNT) {
2033 		slabref = (uma_slabrefcnt_t)slab;
2034 		slab->us_firstfree = slabref->us_freelist[freei].us_item;
2035 	} else {
2036 		slab->us_firstfree = slab->us_freelist[freei].us_item;
2037 	}
2038 	item = slab->us_data + (keg->uk_rsize * freei);
2039 
2040 	slab->us_freecount--;
2041 	keg->uk_free--;
2042 #ifdef INVARIANTS
2043 	uma_dbg_alloc(zone, slab, item);
2044 #endif
2045 	/* Move this slab to the full list */
2046 	if (slab->us_freecount == 0) {
2047 		LIST_REMOVE(slab, us_link);
2048 		LIST_INSERT_HEAD(&keg->uk_full_slab, slab, us_link);
2049 	}
2050 
2051 	return (item);
2052 }
2053 
2054 static int
2055 uma_zalloc_bucket(uma_zone_t zone, int flags)
2056 {
2057 	uma_bucket_t bucket;
2058 	uma_slab_t slab;
2059 	int16_t saved;
2060 	int max, origflags = flags;
2061 
2062 	/*
2063 	 * Try this zone's free list first so we don't allocate extra buckets.
2064 	 */
2065 	if ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) {
2066 		KASSERT(bucket->ub_cnt == 0,
2067 		    ("uma_zalloc_bucket: Bucket on free list is not empty."));
2068 		LIST_REMOVE(bucket, ub_link);
2069 	} else {
2070 		int bflags;
2071 
2072 		bflags = (flags & ~M_ZERO);
2073 		if (zone->uz_keg->uk_flags & UMA_ZFLAG_CACHEONLY)
2074 			bflags |= M_NOVM;
2075 
2076 		ZONE_UNLOCK(zone);
2077 		bucket = bucket_alloc(zone->uz_count, bflags);
2078 		ZONE_LOCK(zone);
2079 	}
2080 
2081 	if (bucket == NULL)
2082 		return (0);
2083 
2084 #ifdef SMP
2085 	/*
2086 	 * This code is here to limit the number of simultaneous bucket fills
2087 	 * for any given zone to the number of per cpu caches in this zone. This
2088 	 * is done so that we don't allocate more memory than we really need.
2089 	 */
2090 	if (zone->uz_fills >= mp_ncpus)
2091 		goto done;
2092 
2093 #endif
2094 	zone->uz_fills++;
2095 
2096 	max = MIN(bucket->ub_entries, zone->uz_count);
2097 	/* Try to keep the buckets totally full */
2098 	saved = bucket->ub_cnt;
2099 	while (bucket->ub_cnt < max &&
2100 	    (slab = uma_zone_slab(zone, flags)) != NULL) {
2101 		while (slab->us_freecount && bucket->ub_cnt < max) {
2102 			bucket->ub_bucket[bucket->ub_cnt++] =
2103 			    uma_slab_alloc(zone, slab);
2104 		}
2105 
2106 		/* Don't block on the next fill */
2107 		flags |= M_NOWAIT;
2108 	}
2109 
2110 	/*
2111 	 * We unlock here because we need to call the zone's init.
2112 	 * It should be safe to unlock because the slab dealt with
2113 	 * above is already on the appropriate list within the keg
2114 	 * and the bucket we filled is not yet on any list, so we
2115 	 * own it.
2116 	 */
2117 	if (zone->uz_init != NULL) {
2118 		int i;
2119 
2120 		ZONE_UNLOCK(zone);
2121 		for (i = saved; i < bucket->ub_cnt; i++)
2122 			if (zone->uz_init(bucket->ub_bucket[i],
2123 			    zone->uz_keg->uk_size, origflags) != 0)
2124 				break;
2125 		/*
2126 		 * If we couldn't initialize the whole bucket, put the
2127 		 * rest back onto the freelist.
2128 		 */
2129 		if (i != bucket->ub_cnt) {
2130 			int j;
2131 
2132 			for (j = i; j < bucket->ub_cnt; j++) {
2133 				uma_zfree_internal(zone, bucket->ub_bucket[j],
2134 				    NULL, SKIP_FINI, 0);
2135 #ifdef INVARIANTS
2136 				bucket->ub_bucket[j] = NULL;
2137 #endif
2138 			}
2139 			bucket->ub_cnt = i;
2140 		}
2141 		ZONE_LOCK(zone);
2142 	}
2143 
2144 	zone->uz_fills--;
2145 	if (bucket->ub_cnt != 0) {
2146 		LIST_INSERT_HEAD(&zone->uz_full_bucket,
2147 		    bucket, ub_link);
2148 		return (1);
2149 	}
2150 #ifdef SMP
2151 done:
2152 #endif
2153 	bucket_free(bucket);
2154 
2155 	return (0);
2156 }
2157 /*
2158  * Allocates an item for an internal zone
2159  *
2160  * Arguments
2161  *	zone   The zone to alloc for.
2162  *	udata  The data to be passed to the constructor.
2163  *	flags  M_WAITOK, M_NOWAIT, M_ZERO.
2164  *
2165  * Returns
2166  *	NULL if there is no memory and M_NOWAIT is set
2167  *	An item if successful
2168  */
2169 
2170 static void *
2171 uma_zalloc_internal(uma_zone_t zone, void *udata, int flags)
2172 {
2173 	uma_keg_t keg;
2174 	uma_slab_t slab;
2175 	void *item;
2176 
2177 	item = NULL;
2178 	keg = zone->uz_keg;
2179 
2180 #ifdef UMA_DEBUG_ALLOC
2181 	printf("INTERNAL: Allocating one item from %s(%p)\n", zone->uz_name, zone);
2182 #endif
2183 	ZONE_LOCK(zone);
2184 
2185 	slab = uma_zone_slab(zone, flags);
2186 	if (slab == NULL) {
2187 		zone->uz_fails++;
2188 		ZONE_UNLOCK(zone);
2189 		return (NULL);
2190 	}
2191 
2192 	item = uma_slab_alloc(zone, slab);
2193 
2194 	zone->uz_allocs++;
2195 
2196 	ZONE_UNLOCK(zone);
2197 
2198 	/*
2199 	 * We have to call both the zone's init (not the keg's init)
2200 	 * and the zone's ctor.  This is because the item is going from
2201 	 * a keg slab directly to the user, and the user is expecting it
2202 	 * to be both zone-init'd as well as zone-ctor'd.
2203 	 */
2204 	if (zone->uz_init != NULL) {
2205 		if (zone->uz_init(item, keg->uk_size, flags) != 0) {
2206 			uma_zfree_internal(zone, item, udata, SKIP_FINI,
2207 			    ZFREE_STATFAIL | ZFREE_STATFREE);
2208 			return (NULL);
2209 		}
2210 	}
2211 	if (zone->uz_ctor != NULL) {
2212 		if (zone->uz_ctor(item, keg->uk_size, udata, flags) != 0) {
2213 			uma_zfree_internal(zone, item, udata, SKIP_DTOR,
2214 			    ZFREE_STATFAIL | ZFREE_STATFREE);
2215 			return (NULL);
2216 		}
2217 	}
2218 	if (flags & M_ZERO)
2219 		bzero(item, keg->uk_size);
2220 
2221 	return (item);
2222 }
2223 
2224 /* See uma.h */
2225 void
2226 uma_zfree_arg(uma_zone_t zone, void *item, void *udata)
2227 {
2228 	uma_keg_t keg;
2229 	uma_cache_t cache;
2230 	uma_bucket_t bucket;
2231 	int bflags;
2232 	int cpu;
2233 
2234 	keg = zone->uz_keg;
2235 
2236 #ifdef UMA_DEBUG_ALLOC_1
2237 	printf("Freeing item %p to %s(%p)\n", item, zone->uz_name, zone);
2238 #endif
2239 	CTR2(KTR_UMA, "uma_zfree_arg thread %x zone %s", curthread,
2240 	    zone->uz_name);
2241 
2242 	if (zone->uz_dtor)
2243 		zone->uz_dtor(item, keg->uk_size, udata);
2244 #ifdef INVARIANTS
2245 	ZONE_LOCK(zone);
2246 	if (keg->uk_flags & UMA_ZONE_MALLOC)
2247 		uma_dbg_free(zone, udata, item);
2248 	else
2249 		uma_dbg_free(zone, NULL, item);
2250 	ZONE_UNLOCK(zone);
2251 #endif
2252 	/*
2253 	 * The race here is acceptable.  If we miss it we'll just have to wait
2254 	 * a little longer for the limits to be reset.
2255 	 */
2256 	if (keg->uk_flags & UMA_ZFLAG_FULL)
2257 		goto zfree_internal;
2258 
2259 	/*
2260 	 * If possible, free to the per-CPU cache.  There are two
2261 	 * requirements for safe access to the per-CPU cache: (1) the thread
2262 	 * accessing the cache must not be preempted or yield during access,
2263 	 * and (2) the thread must not migrate CPUs without switching which
2264 	 * cache it accesses.  We rely on a critical section to prevent
2265 	 * preemption and migration.  We release the critical section in
2266 	 * order to acquire the zone mutex if we are unable to free to the
2267 	 * current cache; when we re-acquire the critical section, we must
2268 	 * detect and handle migration if it has occurred.
2269 	 */
2270 zfree_restart:
2271 	critical_enter();
2272 	cpu = curcpu;
2273 	cache = &zone->uz_cpu[cpu];
2274 
2275 zfree_start:
2276 	bucket = cache->uc_freebucket;
2277 
2278 	if (bucket) {
2279 		/*
2280 		 * Do we have room in our bucket? It is OK for this uz count
2281 		 * check to be slightly out of sync.
2282 		 */
2283 
2284 		if (bucket->ub_cnt < bucket->ub_entries) {
2285 			KASSERT(bucket->ub_bucket[bucket->ub_cnt] == NULL,
2286 			    ("uma_zfree: Freeing to non free bucket index."));
2287 			bucket->ub_bucket[bucket->ub_cnt] = item;
2288 			bucket->ub_cnt++;
2289 			cache->uc_frees++;
2290 			critical_exit();
2291 			return;
2292 		} else if (cache->uc_allocbucket) {
2293 #ifdef UMA_DEBUG_ALLOC
2294 			printf("uma_zfree: Swapping buckets.\n");
2295 #endif
2296 			/*
2297 			 * We have run out of space in our freebucket.
2298 			 * See if we can switch with our alloc bucket.
2299 			 */
2300 			if (cache->uc_allocbucket->ub_cnt <
2301 			    cache->uc_freebucket->ub_cnt) {
2302 				bucket = cache->uc_freebucket;
2303 				cache->uc_freebucket = cache->uc_allocbucket;
2304 				cache->uc_allocbucket = bucket;
2305 				goto zfree_start;
2306 			}
2307 		}
2308 	}
2309 	/*
2310 	 * We can get here for two reasons:
2311 	 *
2312 	 * 1) The buckets are NULL
2313 	 * 2) The alloc and free buckets are both somewhat full.
2314 	 *
2315 	 * We must go back the zone, which requires acquiring the zone lock,
2316 	 * which in turn means we must release and re-acquire the critical
2317 	 * section.  Since the critical section is released, we may be
2318 	 * preempted or migrate.  As such, make sure not to maintain any
2319 	 * thread-local state specific to the cache from prior to releasing
2320 	 * the critical section.
2321 	 */
2322 	critical_exit();
2323 	ZONE_LOCK(zone);
2324 	critical_enter();
2325 	cpu = curcpu;
2326 	cache = &zone->uz_cpu[cpu];
2327 	if (cache->uc_freebucket != NULL) {
2328 		if (cache->uc_freebucket->ub_cnt <
2329 		    cache->uc_freebucket->ub_entries) {
2330 			ZONE_UNLOCK(zone);
2331 			goto zfree_start;
2332 		}
2333 		if (cache->uc_allocbucket != NULL &&
2334 		    (cache->uc_allocbucket->ub_cnt <
2335 		    cache->uc_freebucket->ub_cnt)) {
2336 			ZONE_UNLOCK(zone);
2337 			goto zfree_start;
2338 		}
2339 	}
2340 
2341 	/* Since we have locked the zone we may as well send back our stats */
2342 	zone->uz_allocs += cache->uc_allocs;
2343 	cache->uc_allocs = 0;
2344 	zone->uz_frees += cache->uc_frees;
2345 	cache->uc_frees = 0;
2346 
2347 	bucket = cache->uc_freebucket;
2348 	cache->uc_freebucket = NULL;
2349 
2350 	/* Can we throw this on the zone full list? */
2351 	if (bucket != NULL) {
2352 #ifdef UMA_DEBUG_ALLOC
2353 		printf("uma_zfree: Putting old bucket on the free list.\n");
2354 #endif
2355 		/* ub_cnt is pointing to the last free item */
2356 		KASSERT(bucket->ub_cnt != 0,
2357 		    ("uma_zfree: Attempting to insert an empty bucket onto the full list.\n"));
2358 		LIST_INSERT_HEAD(&zone->uz_full_bucket,
2359 		    bucket, ub_link);
2360 	}
2361 	if ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) {
2362 		LIST_REMOVE(bucket, ub_link);
2363 		ZONE_UNLOCK(zone);
2364 		cache->uc_freebucket = bucket;
2365 		goto zfree_start;
2366 	}
2367 	/* We are no longer associated with this CPU. */
2368 	critical_exit();
2369 
2370 	/* And the zone.. */
2371 	ZONE_UNLOCK(zone);
2372 
2373 #ifdef UMA_DEBUG_ALLOC
2374 	printf("uma_zfree: Allocating new free bucket.\n");
2375 #endif
2376 	bflags = M_NOWAIT;
2377 
2378 	if (keg->uk_flags & UMA_ZFLAG_CACHEONLY)
2379 		bflags |= M_NOVM;
2380 	bucket = bucket_alloc(zone->uz_count, bflags);
2381 	if (bucket) {
2382 		ZONE_LOCK(zone);
2383 		LIST_INSERT_HEAD(&zone->uz_free_bucket,
2384 		    bucket, ub_link);
2385 		ZONE_UNLOCK(zone);
2386 		goto zfree_restart;
2387 	}
2388 
2389 	/*
2390 	 * If nothing else caught this, we'll just do an internal free.
2391 	 */
2392 zfree_internal:
2393 	uma_zfree_internal(zone, item, udata, SKIP_DTOR, ZFREE_STATFREE);
2394 
2395 	return;
2396 }
2397 
2398 /*
2399  * Frees an item to an INTERNAL zone or allocates a free bucket
2400  *
2401  * Arguments:
2402  *	zone   The zone to free to
2403  *	item   The item we're freeing
2404  *	udata  User supplied data for the dtor
2405  *	skip   Skip dtors and finis
2406  */
2407 static void
2408 uma_zfree_internal(uma_zone_t zone, void *item, void *udata,
2409     enum zfreeskip skip, int flags)
2410 {
2411 	uma_slab_t slab;
2412 	uma_slabrefcnt_t slabref;
2413 	uma_keg_t keg;
2414 	u_int8_t *mem;
2415 	u_int8_t freei;
2416 
2417 	keg = zone->uz_keg;
2418 
2419 	if (skip < SKIP_DTOR && zone->uz_dtor)
2420 		zone->uz_dtor(item, keg->uk_size, udata);
2421 	if (skip < SKIP_FINI && zone->uz_fini)
2422 		zone->uz_fini(item, keg->uk_size);
2423 
2424 	ZONE_LOCK(zone);
2425 
2426 	if (flags & ZFREE_STATFAIL)
2427 		zone->uz_fails++;
2428 	if (flags & ZFREE_STATFREE)
2429 		zone->uz_frees++;
2430 
2431 	if (!(keg->uk_flags & UMA_ZONE_MALLOC)) {
2432 		mem = (u_int8_t *)((unsigned long)item & (~UMA_SLAB_MASK));
2433 		if (keg->uk_flags & UMA_ZONE_HASH)
2434 			slab = hash_sfind(&keg->uk_hash, mem);
2435 		else {
2436 			mem += keg->uk_pgoff;
2437 			slab = (uma_slab_t)mem;
2438 		}
2439 	} else {
2440 		slab = (uma_slab_t)udata;
2441 	}
2442 
2443 	/* Do we need to remove from any lists? */
2444 	if (slab->us_freecount+1 == keg->uk_ipers) {
2445 		LIST_REMOVE(slab, us_link);
2446 		LIST_INSERT_HEAD(&keg->uk_free_slab, slab, us_link);
2447 	} else if (slab->us_freecount == 0) {
2448 		LIST_REMOVE(slab, us_link);
2449 		LIST_INSERT_HEAD(&keg->uk_part_slab, slab, us_link);
2450 	}
2451 
2452 	/* Slab management stuff */
2453 	freei = ((unsigned long)item - (unsigned long)slab->us_data)
2454 		/ keg->uk_rsize;
2455 
2456 #ifdef INVARIANTS
2457 	if (!skip)
2458 		uma_dbg_free(zone, slab, item);
2459 #endif
2460 
2461 	if (keg->uk_flags & UMA_ZONE_REFCNT) {
2462 		slabref = (uma_slabrefcnt_t)slab;
2463 		slabref->us_freelist[freei].us_item = slab->us_firstfree;
2464 	} else {
2465 		slab->us_freelist[freei].us_item = slab->us_firstfree;
2466 	}
2467 	slab->us_firstfree = freei;
2468 	slab->us_freecount++;
2469 
2470 	/* Zone statistics */
2471 	keg->uk_free++;
2472 
2473 	if (keg->uk_flags & UMA_ZFLAG_FULL) {
2474 		if (keg->uk_pages < keg->uk_maxpages)
2475 			keg->uk_flags &= ~UMA_ZFLAG_FULL;
2476 
2477 		/*
2478 		 * We can handle one more allocation. Since we're clearing ZFLAG_FULL,
2479 		 * wake up all procs blocked on pages. This should be uncommon, so
2480 		 * keeping this simple for now (rather than adding count of blocked
2481 		 * threads etc).
2482 		 */
2483 		wakeup(keg);
2484 	}
2485 
2486 	ZONE_UNLOCK(zone);
2487 }
2488 
2489 /* See uma.h */
2490 void
2491 uma_zone_set_max(uma_zone_t zone, int nitems)
2492 {
2493 	uma_keg_t keg;
2494 
2495 	keg = zone->uz_keg;
2496 	ZONE_LOCK(zone);
2497 	if (keg->uk_ppera > 1)
2498 		keg->uk_maxpages = nitems * keg->uk_ppera;
2499 	else
2500 		keg->uk_maxpages = nitems / keg->uk_ipers;
2501 
2502 	if (keg->uk_maxpages * keg->uk_ipers < nitems)
2503 		keg->uk_maxpages++;
2504 
2505 	ZONE_UNLOCK(zone);
2506 }
2507 
2508 /* See uma.h */
2509 void
2510 uma_zone_set_init(uma_zone_t zone, uma_init uminit)
2511 {
2512 	ZONE_LOCK(zone);
2513 	KASSERT(zone->uz_keg->uk_pages == 0,
2514 	    ("uma_zone_set_init on non-empty keg"));
2515 	zone->uz_keg->uk_init = uminit;
2516 	ZONE_UNLOCK(zone);
2517 }
2518 
2519 /* See uma.h */
2520 void
2521 uma_zone_set_fini(uma_zone_t zone, uma_fini fini)
2522 {
2523 	ZONE_LOCK(zone);
2524 	KASSERT(zone->uz_keg->uk_pages == 0,
2525 	    ("uma_zone_set_fini on non-empty keg"));
2526 	zone->uz_keg->uk_fini = fini;
2527 	ZONE_UNLOCK(zone);
2528 }
2529 
2530 /* See uma.h */
2531 void
2532 uma_zone_set_zinit(uma_zone_t zone, uma_init zinit)
2533 {
2534 	ZONE_LOCK(zone);
2535 	KASSERT(zone->uz_keg->uk_pages == 0,
2536 	    ("uma_zone_set_zinit on non-empty keg"));
2537 	zone->uz_init = zinit;
2538 	ZONE_UNLOCK(zone);
2539 }
2540 
2541 /* See uma.h */
2542 void
2543 uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini)
2544 {
2545 	ZONE_LOCK(zone);
2546 	KASSERT(zone->uz_keg->uk_pages == 0,
2547 	    ("uma_zone_set_zfini on non-empty keg"));
2548 	zone->uz_fini = zfini;
2549 	ZONE_UNLOCK(zone);
2550 }
2551 
2552 /* See uma.h */
2553 /* XXX uk_freef is not actually used with the zone locked */
2554 void
2555 uma_zone_set_freef(uma_zone_t zone, uma_free freef)
2556 {
2557 	ZONE_LOCK(zone);
2558 	zone->uz_keg->uk_freef = freef;
2559 	ZONE_UNLOCK(zone);
2560 }
2561 
2562 /* See uma.h */
2563 /* XXX uk_allocf is not actually used with the zone locked */
2564 void
2565 uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf)
2566 {
2567 	ZONE_LOCK(zone);
2568 	zone->uz_keg->uk_flags |= UMA_ZFLAG_PRIVALLOC;
2569 	zone->uz_keg->uk_allocf = allocf;
2570 	ZONE_UNLOCK(zone);
2571 }
2572 
2573 /* See uma.h */
2574 int
2575 uma_zone_set_obj(uma_zone_t zone, struct vm_object *obj, int count)
2576 {
2577 	uma_keg_t keg;
2578 	vm_offset_t kva;
2579 	int pages;
2580 
2581 	keg = zone->uz_keg;
2582 	pages = count / keg->uk_ipers;
2583 
2584 	if (pages * keg->uk_ipers < count)
2585 		pages++;
2586 
2587 	kva = kmem_alloc_nofault(kernel_map, pages * UMA_SLAB_SIZE);
2588 
2589 	if (kva == 0)
2590 		return (0);
2591 	if (obj == NULL) {
2592 		obj = vm_object_allocate(OBJT_DEFAULT,
2593 		    pages);
2594 	} else {
2595 		VM_OBJECT_LOCK_INIT(obj, "uma object");
2596 		_vm_object_allocate(OBJT_DEFAULT,
2597 		    pages, obj);
2598 	}
2599 	ZONE_LOCK(zone);
2600 	keg->uk_kva = kva;
2601 	keg->uk_obj = obj;
2602 	keg->uk_maxpages = pages;
2603 	keg->uk_allocf = obj_alloc;
2604 	keg->uk_flags |= UMA_ZONE_NOFREE | UMA_ZFLAG_PRIVALLOC;
2605 	ZONE_UNLOCK(zone);
2606 	return (1);
2607 }
2608 
2609 /* See uma.h */
2610 void
2611 uma_prealloc(uma_zone_t zone, int items)
2612 {
2613 	int slabs;
2614 	uma_slab_t slab;
2615 	uma_keg_t keg;
2616 
2617 	keg = zone->uz_keg;
2618 	ZONE_LOCK(zone);
2619 	slabs = items / keg->uk_ipers;
2620 	if (slabs * keg->uk_ipers < items)
2621 		slabs++;
2622 	while (slabs > 0) {
2623 		slab = slab_zalloc(zone, M_WAITOK);
2624 		LIST_INSERT_HEAD(&keg->uk_free_slab, slab, us_link);
2625 		slabs--;
2626 	}
2627 	ZONE_UNLOCK(zone);
2628 }
2629 
2630 /* See uma.h */
2631 u_int32_t *
2632 uma_find_refcnt(uma_zone_t zone, void *item)
2633 {
2634 	uma_slabrefcnt_t slabref;
2635 	uma_keg_t keg;
2636 	u_int32_t *refcnt;
2637 	int idx;
2638 
2639 	keg = zone->uz_keg;
2640 	slabref = (uma_slabrefcnt_t)vtoslab((vm_offset_t)item &
2641 	    (~UMA_SLAB_MASK));
2642 	KASSERT(slabref != NULL && slabref->us_keg->uk_flags & UMA_ZONE_REFCNT,
2643 	    ("uma_find_refcnt(): zone possibly not UMA_ZONE_REFCNT"));
2644 	idx = ((unsigned long)item - (unsigned long)slabref->us_data)
2645 	    / keg->uk_rsize;
2646 	refcnt = &slabref->us_freelist[idx].us_refcnt;
2647 	return refcnt;
2648 }
2649 
2650 /* See uma.h */
2651 void
2652 uma_reclaim(void)
2653 {
2654 #ifdef UMA_DEBUG
2655 	printf("UMA: vm asked us to release pages!\n");
2656 #endif
2657 	bucket_enable();
2658 	zone_foreach(zone_drain);
2659 	/*
2660 	 * Some slabs may have been freed but this zone will be visited early
2661 	 * we visit again so that we can free pages that are empty once other
2662 	 * zones are drained.  We have to do the same for buckets.
2663 	 */
2664 	zone_drain(slabzone);
2665 	zone_drain(slabrefzone);
2666 	bucket_zone_drain();
2667 }
2668 
2669 /* See uma.h */
2670 int
2671 uma_zone_exhausted(uma_zone_t zone)
2672 {
2673 	int full;
2674 
2675 	ZONE_LOCK(zone);
2676 	full = (zone->uz_keg->uk_flags & UMA_ZFLAG_FULL);
2677 	ZONE_UNLOCK(zone);
2678 	return (full);
2679 }
2680 
2681 int
2682 uma_zone_exhausted_nolock(uma_zone_t zone)
2683 {
2684 	return (zone->uz_keg->uk_flags & UMA_ZFLAG_FULL);
2685 }
2686 
2687 void *
2688 uma_large_malloc(int size, int wait)
2689 {
2690 	void *mem;
2691 	uma_slab_t slab;
2692 	u_int8_t flags;
2693 
2694 	slab = uma_zalloc_internal(slabzone, NULL, wait);
2695 	if (slab == NULL)
2696 		return (NULL);
2697 	mem = page_alloc(NULL, size, &flags, wait);
2698 	if (mem) {
2699 		vsetslab((vm_offset_t)mem, slab);
2700 		slab->us_data = mem;
2701 		slab->us_flags = flags | UMA_SLAB_MALLOC;
2702 		slab->us_size = size;
2703 	} else {
2704 		uma_zfree_internal(slabzone, slab, NULL, SKIP_NONE,
2705 		    ZFREE_STATFAIL | ZFREE_STATFREE);
2706 	}
2707 
2708 	return (mem);
2709 }
2710 
2711 void
2712 uma_large_free(uma_slab_t slab)
2713 {
2714 	vsetobj((vm_offset_t)slab->us_data, kmem_object);
2715 	page_free(slab->us_data, slab->us_size, slab->us_flags);
2716 	uma_zfree_internal(slabzone, slab, NULL, SKIP_NONE, ZFREE_STATFREE);
2717 }
2718 
2719 void
2720 uma_print_stats(void)
2721 {
2722 	zone_foreach(uma_print_zone);
2723 }
2724 
2725 static void
2726 slab_print(uma_slab_t slab)
2727 {
2728 	printf("slab: keg %p, data %p, freecount %d, firstfree %d\n",
2729 		slab->us_keg, slab->us_data, slab->us_freecount,
2730 		slab->us_firstfree);
2731 }
2732 
2733 static void
2734 cache_print(uma_cache_t cache)
2735 {
2736 	printf("alloc: %p(%d), free: %p(%d)\n",
2737 		cache->uc_allocbucket,
2738 		cache->uc_allocbucket?cache->uc_allocbucket->ub_cnt:0,
2739 		cache->uc_freebucket,
2740 		cache->uc_freebucket?cache->uc_freebucket->ub_cnt:0);
2741 }
2742 
2743 void
2744 uma_print_zone(uma_zone_t zone)
2745 {
2746 	uma_cache_t cache;
2747 	uma_keg_t keg;
2748 	uma_slab_t slab;
2749 	int i;
2750 
2751 	keg = zone->uz_keg;
2752 	printf("%s(%p) size %d(%d) flags %d ipers %d ppera %d out %d free %d\n",
2753 	    zone->uz_name, zone, keg->uk_size, keg->uk_rsize, keg->uk_flags,
2754 	    keg->uk_ipers, keg->uk_ppera,
2755 	    (keg->uk_ipers * keg->uk_pages) - keg->uk_free, keg->uk_free);
2756 	printf("Part slabs:\n");
2757 	LIST_FOREACH(slab, &keg->uk_part_slab, us_link)
2758 		slab_print(slab);
2759 	printf("Free slabs:\n");
2760 	LIST_FOREACH(slab, &keg->uk_free_slab, us_link)
2761 		slab_print(slab);
2762 	printf("Full slabs:\n");
2763 	LIST_FOREACH(slab, &keg->uk_full_slab, us_link)
2764 		slab_print(slab);
2765 	for (i = 0; i <= mp_maxid; i++) {
2766 		if (CPU_ABSENT(i))
2767 			continue;
2768 		cache = &zone->uz_cpu[i];
2769 		printf("CPU %d Cache:\n", i);
2770 		cache_print(cache);
2771 	}
2772 }
2773 
2774 #ifdef DDB
2775 /*
2776  * Generate statistics across both the zone and its per-cpu cache's.  Return
2777  * desired statistics if the pointer is non-NULL for that statistic.
2778  *
2779  * Note: does not update the zone statistics, as it can't safely clear the
2780  * per-CPU cache statistic.
2781  *
2782  * XXXRW: Following the uc_allocbucket and uc_freebucket pointers here isn't
2783  * safe from off-CPU; we should modify the caches to track this information
2784  * directly so that we don't have to.
2785  */
2786 static void
2787 uma_zone_sumstat(uma_zone_t z, int *cachefreep, u_int64_t *allocsp,
2788     u_int64_t *freesp)
2789 {
2790 	uma_cache_t cache;
2791 	u_int64_t allocs, frees;
2792 	int cachefree, cpu;
2793 
2794 	allocs = frees = 0;
2795 	cachefree = 0;
2796 	for (cpu = 0; cpu <= mp_maxid; cpu++) {
2797 		if (CPU_ABSENT(cpu))
2798 			continue;
2799 		cache = &z->uz_cpu[cpu];
2800 		if (cache->uc_allocbucket != NULL)
2801 			cachefree += cache->uc_allocbucket->ub_cnt;
2802 		if (cache->uc_freebucket != NULL)
2803 			cachefree += cache->uc_freebucket->ub_cnt;
2804 		allocs += cache->uc_allocs;
2805 		frees += cache->uc_frees;
2806 	}
2807 	allocs += z->uz_allocs;
2808 	frees += z->uz_frees;
2809 	if (cachefreep != NULL)
2810 		*cachefreep = cachefree;
2811 	if (allocsp != NULL)
2812 		*allocsp = allocs;
2813 	if (freesp != NULL)
2814 		*freesp = frees;
2815 }
2816 #endif /* DDB */
2817 
2818 static int
2819 sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS)
2820 {
2821 	uma_keg_t kz;
2822 	uma_zone_t z;
2823 	int count;
2824 
2825 	count = 0;
2826 	mtx_lock(&uma_mtx);
2827 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
2828 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
2829 			count++;
2830 	}
2831 	mtx_unlock(&uma_mtx);
2832 	return (sysctl_handle_int(oidp, &count, 0, req));
2833 }
2834 
2835 static int
2836 sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS)
2837 {
2838 	struct uma_stream_header ush;
2839 	struct uma_type_header uth;
2840 	struct uma_percpu_stat ups;
2841 	uma_bucket_t bucket;
2842 	struct sbuf sbuf;
2843 	uma_cache_t cache;
2844 	uma_keg_t kz;
2845 	uma_zone_t z;
2846 	char *buffer;
2847 	int buflen, count, error, i;
2848 
2849 	mtx_lock(&uma_mtx);
2850 restart:
2851 	mtx_assert(&uma_mtx, MA_OWNED);
2852 	count = 0;
2853 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
2854 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
2855 			count++;
2856 	}
2857 	mtx_unlock(&uma_mtx);
2858 
2859 	buflen = sizeof(ush) + count * (sizeof(uth) + sizeof(ups) *
2860 	    (mp_maxid + 1)) + 1;
2861 	buffer = malloc(buflen, M_TEMP, M_WAITOK | M_ZERO);
2862 
2863 	mtx_lock(&uma_mtx);
2864 	i = 0;
2865 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
2866 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
2867 			i++;
2868 	}
2869 	if (i > count) {
2870 		free(buffer, M_TEMP);
2871 		goto restart;
2872 	}
2873 	count =  i;
2874 
2875 	sbuf_new(&sbuf, buffer, buflen, SBUF_FIXEDLEN);
2876 
2877 	/*
2878 	 * Insert stream header.
2879 	 */
2880 	bzero(&ush, sizeof(ush));
2881 	ush.ush_version = UMA_STREAM_VERSION;
2882 	ush.ush_maxcpus = (mp_maxid + 1);
2883 	ush.ush_count = count;
2884 	if (sbuf_bcat(&sbuf, &ush, sizeof(ush)) < 0) {
2885 		mtx_unlock(&uma_mtx);
2886 		error = ENOMEM;
2887 		goto out;
2888 	}
2889 
2890 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
2891 		LIST_FOREACH(z, &kz->uk_zones, uz_link) {
2892 			bzero(&uth, sizeof(uth));
2893 			ZONE_LOCK(z);
2894 			strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
2895 			uth.uth_align = kz->uk_align;
2896 			uth.uth_pages = kz->uk_pages;
2897 			uth.uth_keg_free = kz->uk_free;
2898 			uth.uth_size = kz->uk_size;
2899 			uth.uth_rsize = kz->uk_rsize;
2900 			uth.uth_maxpages = kz->uk_maxpages;
2901 			if (kz->uk_ppera > 1)
2902 				uth.uth_limit = kz->uk_maxpages /
2903 				    kz->uk_ppera;
2904 			else
2905 				uth.uth_limit = kz->uk_maxpages *
2906 				    kz->uk_ipers;
2907 
2908 			/*
2909 			 * A zone is secondary is it is not the first entry
2910 			 * on the keg's zone list.
2911 			 */
2912 			if ((kz->uk_flags & UMA_ZONE_SECONDARY) &&
2913 			    (LIST_FIRST(&kz->uk_zones) != z))
2914 				uth.uth_zone_flags = UTH_ZONE_SECONDARY;
2915 
2916 			LIST_FOREACH(bucket, &z->uz_full_bucket, ub_link)
2917 				uth.uth_zone_free += bucket->ub_cnt;
2918 			uth.uth_allocs = z->uz_allocs;
2919 			uth.uth_frees = z->uz_frees;
2920 			uth.uth_fails = z->uz_fails;
2921 			if (sbuf_bcat(&sbuf, &uth, sizeof(uth)) < 0) {
2922 				ZONE_UNLOCK(z);
2923 				mtx_unlock(&uma_mtx);
2924 				error = ENOMEM;
2925 				goto out;
2926 			}
2927 			/*
2928 			 * While it is not normally safe to access the cache
2929 			 * bucket pointers while not on the CPU that owns the
2930 			 * cache, we only allow the pointers to be exchanged
2931 			 * without the zone lock held, not invalidated, so
2932 			 * accept the possible race associated with bucket
2933 			 * exchange during monitoring.
2934 			 */
2935 			for (i = 0; i < (mp_maxid + 1); i++) {
2936 				bzero(&ups, sizeof(ups));
2937 				if (kz->uk_flags & UMA_ZFLAG_INTERNAL)
2938 					goto skip;
2939 				if (CPU_ABSENT(i))
2940 					goto skip;
2941 				cache = &z->uz_cpu[i];
2942 				if (cache->uc_allocbucket != NULL)
2943 					ups.ups_cache_free +=
2944 					    cache->uc_allocbucket->ub_cnt;
2945 				if (cache->uc_freebucket != NULL)
2946 					ups.ups_cache_free +=
2947 					    cache->uc_freebucket->ub_cnt;
2948 				ups.ups_allocs = cache->uc_allocs;
2949 				ups.ups_frees = cache->uc_frees;
2950 skip:
2951 				if (sbuf_bcat(&sbuf, &ups, sizeof(ups)) < 0) {
2952 					ZONE_UNLOCK(z);
2953 					mtx_unlock(&uma_mtx);
2954 					error = ENOMEM;
2955 					goto out;
2956 				}
2957 			}
2958 			ZONE_UNLOCK(z);
2959 		}
2960 	}
2961 	mtx_unlock(&uma_mtx);
2962 	sbuf_finish(&sbuf);
2963 	error = SYSCTL_OUT(req, sbuf_data(&sbuf), sbuf_len(&sbuf));
2964 out:
2965 	free(buffer, M_TEMP);
2966 	return (error);
2967 }
2968 
2969 #ifdef DDB
2970 DB_SHOW_COMMAND(uma, db_show_uma)
2971 {
2972 	u_int64_t allocs, frees;
2973 	uma_bucket_t bucket;
2974 	uma_keg_t kz;
2975 	uma_zone_t z;
2976 	int cachefree;
2977 
2978 	db_printf("%18s %8s %8s %8s %12s\n", "Zone", "Size", "Used", "Free",
2979 	    "Requests");
2980 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
2981 		LIST_FOREACH(z, &kz->uk_zones, uz_link) {
2982 			if (kz->uk_flags & UMA_ZFLAG_INTERNAL) {
2983 				allocs = z->uz_allocs;
2984 				frees = z->uz_frees;
2985 				cachefree = 0;
2986 			} else
2987 				uma_zone_sumstat(z, &cachefree, &allocs,
2988 				    &frees);
2989 			if (!((kz->uk_flags & UMA_ZONE_SECONDARY) &&
2990 			    (LIST_FIRST(&kz->uk_zones) != z)))
2991 				cachefree += kz->uk_free;
2992 			LIST_FOREACH(bucket, &z->uz_full_bucket, ub_link)
2993 				cachefree += bucket->ub_cnt;
2994 			db_printf("%18s %8ju %8jd %8d %12ju\n", z->uz_name,
2995 			    (uintmax_t)kz->uk_size,
2996 			    (intmax_t)(allocs - frees), cachefree,
2997 			    (uintmax_t)allocs);
2998 		}
2999 	}
3000 }
3001 #endif
3002