xref: /freebsd/sys/vm/uma_core.c (revision 6e660824a82f590542932de52f128db584029893)
1 /*-
2  * Copyright (c) 2002-2005, 2009, 2013 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 #include "opt_vm.h"
63 
64 #include <sys/param.h>
65 #include <sys/systm.h>
66 #include <sys/bitset.h>
67 #include <sys/kernel.h>
68 #include <sys/types.h>
69 #include <sys/queue.h>
70 #include <sys/malloc.h>
71 #include <sys/ktr.h>
72 #include <sys/lock.h>
73 #include <sys/sysctl.h>
74 #include <sys/mutex.h>
75 #include <sys/proc.h>
76 #include <sys/rwlock.h>
77 #include <sys/sbuf.h>
78 #include <sys/smp.h>
79 #include <sys/vmmeter.h>
80 
81 #include <vm/vm.h>
82 #include <vm/vm_object.h>
83 #include <vm/vm_page.h>
84 #include <vm/vm_pageout.h>
85 #include <vm/vm_param.h>
86 #include <vm/vm_map.h>
87 #include <vm/vm_kern.h>
88 #include <vm/vm_extern.h>
89 #include <vm/uma.h>
90 #include <vm/uma_int.h>
91 #include <vm/uma_dbg.h>
92 
93 #include <ddb/ddb.h>
94 
95 #ifdef DEBUG_MEMGUARD
96 #include <vm/memguard.h>
97 #endif
98 
99 /*
100  * This is the zone and keg from which all zones are spawned.  The idea is that
101  * even the zone & keg heads are allocated from the allocator, so we use the
102  * bss section to bootstrap us.
103  */
104 static struct uma_keg masterkeg;
105 static struct uma_zone masterzone_k;
106 static struct uma_zone masterzone_z;
107 static uma_zone_t kegs = &masterzone_k;
108 static uma_zone_t zones = &masterzone_z;
109 
110 /* This is the zone from which all of uma_slab_t's are allocated. */
111 static uma_zone_t slabzone;
112 static uma_zone_t slabrefzone;	/* With refcounters (for UMA_ZONE_REFCNT) */
113 
114 /*
115  * The initial hash tables come out of this zone so they can be allocated
116  * prior to malloc coming up.
117  */
118 static uma_zone_t hashzone;
119 
120 /* The boot-time adjusted value for cache line alignment. */
121 int uma_align_cache = 64 - 1;
122 
123 static MALLOC_DEFINE(M_UMAHASH, "UMAHash", "UMA Hash Buckets");
124 
125 /*
126  * Are we allowed to allocate buckets?
127  */
128 static int bucketdisable = 1;
129 
130 /* Linked list of all kegs in the system */
131 static LIST_HEAD(,uma_keg) uma_kegs = LIST_HEAD_INITIALIZER(uma_kegs);
132 
133 /* This mutex protects the keg list */
134 static struct mtx_padalign uma_mtx;
135 
136 /* Linked list of boot time pages */
137 static LIST_HEAD(,uma_slab) uma_boot_pages =
138     LIST_HEAD_INITIALIZER(uma_boot_pages);
139 
140 /* This mutex protects the boot time pages list */
141 static struct mtx_padalign uma_boot_pages_mtx;
142 
143 /* Is the VM done starting up? */
144 static int booted = 0;
145 #define	UMA_STARTUP	1
146 #define	UMA_STARTUP2	2
147 
148 /* Maximum number of allowed items-per-slab if the slab header is OFFPAGE */
149 static const u_int uma_max_ipers = SLAB_SETSIZE;
150 
151 /*
152  * Only mbuf clusters use ref zones.  Just provide enough references
153  * to support the one user.  New code should not use the ref facility.
154  */
155 static const u_int uma_max_ipers_ref = PAGE_SIZE / MCLBYTES;
156 
157 /*
158  * This is the handle used to schedule events that need to happen
159  * outside of the allocation fast path.
160  */
161 static struct callout uma_callout;
162 #define	UMA_TIMEOUT	20		/* Seconds for callout interval. */
163 
164 /*
165  * This structure is passed as the zone ctor arg so that I don't have to create
166  * a special allocation function just for zones.
167  */
168 struct uma_zctor_args {
169 	const char *name;
170 	size_t size;
171 	uma_ctor ctor;
172 	uma_dtor dtor;
173 	uma_init uminit;
174 	uma_fini fini;
175 	uma_import import;
176 	uma_release release;
177 	void *arg;
178 	uma_keg_t keg;
179 	int align;
180 	uint32_t flags;
181 };
182 
183 struct uma_kctor_args {
184 	uma_zone_t zone;
185 	size_t size;
186 	uma_init uminit;
187 	uma_fini fini;
188 	int align;
189 	uint32_t flags;
190 };
191 
192 struct uma_bucket_zone {
193 	uma_zone_t	ubz_zone;
194 	char		*ubz_name;
195 	int		ubz_entries;	/* Number of items it can hold. */
196 	int		ubz_maxsize;	/* Maximum allocation size per-item. */
197 };
198 
199 /*
200  * Compute the actual number of bucket entries to pack them in power
201  * of two sizes for more efficient space utilization.
202  */
203 #define	BUCKET_SIZE(n)						\
204     (((sizeof(void *) * (n)) - sizeof(struct uma_bucket)) / sizeof(void *))
205 
206 #define	BUCKET_MAX	BUCKET_SIZE(128)
207 
208 struct uma_bucket_zone bucket_zones[] = {
209 	{ NULL, "4 Bucket", BUCKET_SIZE(4), 4096 },
210 	{ NULL, "8 Bucket", BUCKET_SIZE(8), 2048 },
211 	{ NULL, "16 Bucket", BUCKET_SIZE(16), 1024 },
212 	{ NULL, "32 Bucket", BUCKET_SIZE(32), 512 },
213 	{ NULL, "64 Bucket", BUCKET_SIZE(64), 256 },
214 	{ NULL, "128 Bucket", BUCKET_SIZE(128), 128 },
215 	{ NULL, NULL, 0}
216 };
217 
218 /*
219  * Flags and enumerations to be passed to internal functions.
220  */
221 enum zfreeskip { SKIP_NONE = 0, SKIP_DTOR, SKIP_FINI };
222 
223 /* Prototypes.. */
224 
225 static void *noobj_alloc(uma_zone_t, int, uint8_t *, int);
226 static void *page_alloc(uma_zone_t, int, uint8_t *, int);
227 static void *startup_alloc(uma_zone_t, int, uint8_t *, int);
228 static void page_free(void *, int, uint8_t);
229 static uma_slab_t keg_alloc_slab(uma_keg_t, uma_zone_t, int);
230 static void cache_drain(uma_zone_t);
231 static void bucket_drain(uma_zone_t, uma_bucket_t);
232 static void bucket_cache_drain(uma_zone_t zone);
233 static int keg_ctor(void *, int, void *, int);
234 static void keg_dtor(void *, int, void *);
235 static int zone_ctor(void *, int, void *, int);
236 static void zone_dtor(void *, int, void *);
237 static int zero_init(void *, int, int);
238 static void keg_small_init(uma_keg_t keg);
239 static void keg_large_init(uma_keg_t keg);
240 static void zone_foreach(void (*zfunc)(uma_zone_t));
241 static void zone_timeout(uma_zone_t zone);
242 static int hash_alloc(struct uma_hash *);
243 static int hash_expand(struct uma_hash *, struct uma_hash *);
244 static void hash_free(struct uma_hash *hash);
245 static void uma_timeout(void *);
246 static void uma_startup3(void);
247 static void *zone_alloc_item(uma_zone_t, void *, int);
248 static void zone_free_item(uma_zone_t, void *, void *, enum zfreeskip);
249 static void bucket_enable(void);
250 static void bucket_init(void);
251 static uma_bucket_t bucket_alloc(uma_zone_t zone, void *, int);
252 static void bucket_free(uma_zone_t zone, uma_bucket_t, void *);
253 static void bucket_zone_drain(void);
254 static uma_bucket_t zone_alloc_bucket(uma_zone_t zone, void *, int flags);
255 static uma_slab_t zone_fetch_slab(uma_zone_t zone, uma_keg_t last, int flags);
256 static uma_slab_t zone_fetch_slab_multi(uma_zone_t zone, uma_keg_t last, int flags);
257 static void *slab_alloc_item(uma_keg_t keg, uma_slab_t slab);
258 static void slab_free_item(uma_keg_t keg, uma_slab_t slab, void *item);
259 static uma_keg_t uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit,
260     uma_fini fini, int align, uint32_t flags);
261 static int zone_import(uma_zone_t zone, void **bucket, int max, int flags);
262 static void zone_release(uma_zone_t zone, void **bucket, int cnt);
263 
264 void uma_print_zone(uma_zone_t);
265 void uma_print_stats(void);
266 static int sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS);
267 static int sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS);
268 
269 SYSINIT(uma_startup3, SI_SUB_VM_CONF, SI_ORDER_SECOND, uma_startup3, NULL);
270 
271 SYSCTL_PROC(_vm, OID_AUTO, zone_count, CTLFLAG_RD|CTLTYPE_INT,
272     0, 0, sysctl_vm_zone_count, "I", "Number of UMA zones");
273 
274 SYSCTL_PROC(_vm, OID_AUTO, zone_stats, CTLFLAG_RD|CTLTYPE_STRUCT,
275     0, 0, sysctl_vm_zone_stats, "s,struct uma_type_header", "Zone Stats");
276 
277 static int zone_warnings = 1;
278 TUNABLE_INT("vm.zone_warnings", &zone_warnings);
279 SYSCTL_INT(_vm, OID_AUTO, zone_warnings, CTLFLAG_RW, &zone_warnings, 0,
280     "Warn when UMA zones becomes full");
281 
282 /*
283  * This routine checks to see whether or not it's safe to enable buckets.
284  */
285 static void
286 bucket_enable(void)
287 {
288 	bucketdisable = vm_page_count_min();
289 }
290 
291 /*
292  * Initialize bucket_zones, the array of zones of buckets of various sizes.
293  *
294  * For each zone, calculate the memory required for each bucket, consisting
295  * of the header and an array of pointers.
296  */
297 static void
298 bucket_init(void)
299 {
300 	struct uma_bucket_zone *ubz;
301 	int size;
302 	int i;
303 
304 	for (i = 0, ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++) {
305 		size = roundup(sizeof(struct uma_bucket), sizeof(void *));
306 		size += sizeof(void *) * ubz->ubz_entries;
307 		ubz->ubz_zone = uma_zcreate(ubz->ubz_name, size,
308 		    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR,
309 		    UMA_ZONE_MTXCLASS | UMA_ZFLAG_BUCKET);
310 	}
311 }
312 
313 /*
314  * Given a desired number of entries for a bucket, return the zone from which
315  * to allocate the bucket.
316  */
317 static struct uma_bucket_zone *
318 bucket_zone_lookup(int entries)
319 {
320 	struct uma_bucket_zone *ubz;
321 
322 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
323 		if (ubz->ubz_entries >= entries)
324 			return (ubz);
325 	ubz--;
326 	return (ubz);
327 }
328 
329 static int
330 bucket_select(int size)
331 {
332 	struct uma_bucket_zone *ubz;
333 
334 	ubz = &bucket_zones[0];
335 	if (size > ubz->ubz_maxsize)
336 		return MAX((ubz->ubz_maxsize * ubz->ubz_entries) / size, 1);
337 
338 	for (; ubz->ubz_entries != 0; ubz++)
339 		if (ubz->ubz_maxsize < size)
340 			break;
341 	ubz--;
342 	return (ubz->ubz_entries);
343 }
344 
345 static uma_bucket_t
346 bucket_alloc(uma_zone_t zone, void *udata, int flags)
347 {
348 	struct uma_bucket_zone *ubz;
349 	uma_bucket_t bucket;
350 
351 	/*
352 	 * This is to stop us from allocating per cpu buckets while we're
353 	 * running out of vm.boot_pages.  Otherwise, we would exhaust the
354 	 * boot pages.  This also prevents us from allocating buckets in
355 	 * low memory situations.
356 	 */
357 	if (bucketdisable)
358 		return (NULL);
359 	/*
360 	 * To limit bucket recursion we store the original zone flags
361 	 * in a cookie passed via zalloc_arg/zfree_arg.  This allows the
362 	 * NOVM flag to persist even through deep recursions.  We also
363 	 * store ZFLAG_BUCKET once we have recursed attempting to allocate
364 	 * a bucket for a bucket zone so we do not allow infinite bucket
365 	 * recursion.  This cookie will even persist to frees of unused
366 	 * buckets via the allocation path or bucket allocations in the
367 	 * free path.
368 	 */
369 	if ((uintptr_t)udata & UMA_ZFLAG_BUCKET)
370 		return (NULL);
371 	if ((zone->uz_flags & UMA_ZFLAG_BUCKET) == 0)
372 		udata = (void *)(uintptr_t)zone->uz_flags;
373 	else
374 		udata = (void *)((uintptr_t)udata | UMA_ZFLAG_BUCKET);
375 	if ((uintptr_t)udata & UMA_ZFLAG_CACHEONLY)
376 		flags |= M_NOVM;
377 	ubz = bucket_zone_lookup(zone->uz_count);
378 	bucket = uma_zalloc_arg(ubz->ubz_zone, udata, flags);
379 	if (bucket) {
380 #ifdef INVARIANTS
381 		bzero(bucket->ub_bucket, sizeof(void *) * ubz->ubz_entries);
382 #endif
383 		bucket->ub_cnt = 0;
384 		bucket->ub_entries = ubz->ubz_entries;
385 	}
386 
387 	return (bucket);
388 }
389 
390 static void
391 bucket_free(uma_zone_t zone, uma_bucket_t bucket, void *udata)
392 {
393 	struct uma_bucket_zone *ubz;
394 
395 	KASSERT(bucket->ub_cnt == 0,
396 	    ("bucket_free: Freeing a non free bucket."));
397 	if ((zone->uz_flags & UMA_ZFLAG_BUCKET) == 0)
398 		udata = (void *)(uintptr_t)zone->uz_flags;
399 	ubz = bucket_zone_lookup(bucket->ub_entries);
400 	uma_zfree_arg(ubz->ubz_zone, bucket, udata);
401 }
402 
403 static void
404 bucket_zone_drain(void)
405 {
406 	struct uma_bucket_zone *ubz;
407 
408 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
409 		zone_drain(ubz->ubz_zone);
410 }
411 
412 static void
413 zone_log_warning(uma_zone_t zone)
414 {
415 	static const struct timeval warninterval = { 300, 0 };
416 
417 	if (!zone_warnings || zone->uz_warning == NULL)
418 		return;
419 
420 	if (ratecheck(&zone->uz_ratecheck, &warninterval))
421 		printf("[zone: %s] %s\n", zone->uz_name, zone->uz_warning);
422 }
423 
424 static void
425 zone_foreach_keg(uma_zone_t zone, void (*kegfn)(uma_keg_t))
426 {
427 	uma_klink_t klink;
428 
429 	LIST_FOREACH(klink, &zone->uz_kegs, kl_link)
430 		kegfn(klink->kl_keg);
431 }
432 
433 /*
434  * Routine called by timeout which is used to fire off some time interval
435  * based calculations.  (stats, hash size, etc.)
436  *
437  * Arguments:
438  *	arg   Unused
439  *
440  * Returns:
441  *	Nothing
442  */
443 static void
444 uma_timeout(void *unused)
445 {
446 	bucket_enable();
447 	zone_foreach(zone_timeout);
448 
449 	/* Reschedule this event */
450 	callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
451 }
452 
453 /*
454  * Routine to perform timeout driven calculations.  This expands the
455  * hashes and does per cpu statistics aggregation.
456  *
457  *  Returns nothing.
458  */
459 static void
460 keg_timeout(uma_keg_t keg)
461 {
462 
463 	KEG_LOCK(keg);
464 	/*
465 	 * Expand the keg hash table.
466 	 *
467 	 * This is done if the number of slabs is larger than the hash size.
468 	 * What I'm trying to do here is completely reduce collisions.  This
469 	 * may be a little aggressive.  Should I allow for two collisions max?
470 	 */
471 	if (keg->uk_flags & UMA_ZONE_HASH &&
472 	    keg->uk_pages / keg->uk_ppera >= keg->uk_hash.uh_hashsize) {
473 		struct uma_hash newhash;
474 		struct uma_hash oldhash;
475 		int ret;
476 
477 		/*
478 		 * This is so involved because allocating and freeing
479 		 * while the keg lock is held will lead to deadlock.
480 		 * I have to do everything in stages and check for
481 		 * races.
482 		 */
483 		newhash = keg->uk_hash;
484 		KEG_UNLOCK(keg);
485 		ret = hash_alloc(&newhash);
486 		KEG_LOCK(keg);
487 		if (ret) {
488 			if (hash_expand(&keg->uk_hash, &newhash)) {
489 				oldhash = keg->uk_hash;
490 				keg->uk_hash = newhash;
491 			} else
492 				oldhash = newhash;
493 
494 			KEG_UNLOCK(keg);
495 			hash_free(&oldhash);
496 			return;
497 		}
498 	}
499 	KEG_UNLOCK(keg);
500 }
501 
502 static void
503 zone_timeout(uma_zone_t zone)
504 {
505 
506 	zone_foreach_keg(zone, &keg_timeout);
507 }
508 
509 /*
510  * Allocate and zero fill the next sized hash table from the appropriate
511  * backing store.
512  *
513  * Arguments:
514  *	hash  A new hash structure with the old hash size in uh_hashsize
515  *
516  * Returns:
517  *	1 on sucess and 0 on failure.
518  */
519 static int
520 hash_alloc(struct uma_hash *hash)
521 {
522 	int oldsize;
523 	int alloc;
524 
525 	oldsize = hash->uh_hashsize;
526 
527 	/* We're just going to go to a power of two greater */
528 	if (oldsize)  {
529 		hash->uh_hashsize = oldsize * 2;
530 		alloc = sizeof(hash->uh_slab_hash[0]) * hash->uh_hashsize;
531 		hash->uh_slab_hash = (struct slabhead *)malloc(alloc,
532 		    M_UMAHASH, M_NOWAIT);
533 	} else {
534 		alloc = sizeof(hash->uh_slab_hash[0]) * UMA_HASH_SIZE_INIT;
535 		hash->uh_slab_hash = zone_alloc_item(hashzone, NULL,
536 		    M_WAITOK);
537 		hash->uh_hashsize = UMA_HASH_SIZE_INIT;
538 	}
539 	if (hash->uh_slab_hash) {
540 		bzero(hash->uh_slab_hash, alloc);
541 		hash->uh_hashmask = hash->uh_hashsize - 1;
542 		return (1);
543 	}
544 
545 	return (0);
546 }
547 
548 /*
549  * Expands the hash table for HASH zones.  This is done from zone_timeout
550  * to reduce collisions.  This must not be done in the regular allocation
551  * path, otherwise, we can recurse on the vm while allocating pages.
552  *
553  * Arguments:
554  *	oldhash  The hash you want to expand
555  *	newhash  The hash structure for the new table
556  *
557  * Returns:
558  *	Nothing
559  *
560  * Discussion:
561  */
562 static int
563 hash_expand(struct uma_hash *oldhash, struct uma_hash *newhash)
564 {
565 	uma_slab_t slab;
566 	int hval;
567 	int i;
568 
569 	if (!newhash->uh_slab_hash)
570 		return (0);
571 
572 	if (oldhash->uh_hashsize >= newhash->uh_hashsize)
573 		return (0);
574 
575 	/*
576 	 * I need to investigate hash algorithms for resizing without a
577 	 * full rehash.
578 	 */
579 
580 	for (i = 0; i < oldhash->uh_hashsize; i++)
581 		while (!SLIST_EMPTY(&oldhash->uh_slab_hash[i])) {
582 			slab = SLIST_FIRST(&oldhash->uh_slab_hash[i]);
583 			SLIST_REMOVE_HEAD(&oldhash->uh_slab_hash[i], us_hlink);
584 			hval = UMA_HASH(newhash, slab->us_data);
585 			SLIST_INSERT_HEAD(&newhash->uh_slab_hash[hval],
586 			    slab, us_hlink);
587 		}
588 
589 	return (1);
590 }
591 
592 /*
593  * Free the hash bucket to the appropriate backing store.
594  *
595  * Arguments:
596  *	slab_hash  The hash bucket we're freeing
597  *	hashsize   The number of entries in that hash bucket
598  *
599  * Returns:
600  *	Nothing
601  */
602 static void
603 hash_free(struct uma_hash *hash)
604 {
605 	if (hash->uh_slab_hash == NULL)
606 		return;
607 	if (hash->uh_hashsize == UMA_HASH_SIZE_INIT)
608 		zone_free_item(hashzone, hash->uh_slab_hash, NULL, SKIP_NONE);
609 	else
610 		free(hash->uh_slab_hash, M_UMAHASH);
611 }
612 
613 /*
614  * Frees all outstanding items in a bucket
615  *
616  * Arguments:
617  *	zone   The zone to free to, must be unlocked.
618  *	bucket The free/alloc bucket with items, cpu queue must be locked.
619  *
620  * Returns:
621  *	Nothing
622  */
623 
624 static void
625 bucket_drain(uma_zone_t zone, uma_bucket_t bucket)
626 {
627 	int i;
628 
629 	if (bucket == NULL)
630 		return;
631 
632 	if (zone->uz_fini)
633 		for (i = 0; i < bucket->ub_cnt; i++)
634 			zone->uz_fini(bucket->ub_bucket[i], zone->uz_size);
635 	zone->uz_release(zone->uz_arg, bucket->ub_bucket, bucket->ub_cnt);
636 	bucket->ub_cnt = 0;
637 }
638 
639 /*
640  * Drains the per cpu caches for a zone.
641  *
642  * NOTE: This may only be called while the zone is being turn down, and not
643  * during normal operation.  This is necessary in order that we do not have
644  * to migrate CPUs to drain the per-CPU caches.
645  *
646  * Arguments:
647  *	zone     The zone to drain, must be unlocked.
648  *
649  * Returns:
650  *	Nothing
651  */
652 static void
653 cache_drain(uma_zone_t zone)
654 {
655 	uma_cache_t cache;
656 	int cpu;
657 
658 	/*
659 	 * XXX: It is safe to not lock the per-CPU caches, because we're
660 	 * tearing down the zone anyway.  I.e., there will be no further use
661 	 * of the caches at this point.
662 	 *
663 	 * XXX: It would good to be able to assert that the zone is being
664 	 * torn down to prevent improper use of cache_drain().
665 	 *
666 	 * XXX: We lock the zone before passing into bucket_cache_drain() as
667 	 * it is used elsewhere.  Should the tear-down path be made special
668 	 * there in some form?
669 	 */
670 	CPU_FOREACH(cpu) {
671 		cache = &zone->uz_cpu[cpu];
672 		bucket_drain(zone, cache->uc_allocbucket);
673 		bucket_drain(zone, cache->uc_freebucket);
674 		if (cache->uc_allocbucket != NULL)
675 			bucket_free(zone, cache->uc_allocbucket, NULL);
676 		if (cache->uc_freebucket != NULL)
677 			bucket_free(zone, cache->uc_freebucket, NULL);
678 		cache->uc_allocbucket = cache->uc_freebucket = NULL;
679 	}
680 	ZONE_LOCK(zone);
681 	bucket_cache_drain(zone);
682 	ZONE_UNLOCK(zone);
683 }
684 
685 /*
686  * Drain the cached buckets from a zone.  Expects a locked zone on entry.
687  */
688 static void
689 bucket_cache_drain(uma_zone_t zone)
690 {
691 	uma_bucket_t bucket;
692 
693 	/*
694 	 * Drain the bucket queues and free the buckets, we just keep two per
695 	 * cpu (alloc/free).
696 	 */
697 	while ((bucket = LIST_FIRST(&zone->uz_buckets)) != NULL) {
698 		LIST_REMOVE(bucket, ub_link);
699 		ZONE_UNLOCK(zone);
700 		bucket_drain(zone, bucket);
701 		bucket_free(zone, bucket, NULL);
702 		ZONE_LOCK(zone);
703 	}
704 }
705 
706 static void
707 keg_free_slab(uma_keg_t keg, uma_slab_t slab, int start)
708 {
709 	uint8_t *mem;
710 	int i;
711 	uint8_t flags;
712 
713 	mem = slab->us_data;
714 	flags = slab->us_flags;
715 	i = start;
716 	if (keg->uk_fini != NULL) {
717 		for (i--; i > -1; i--)
718 			keg->uk_fini(slab->us_data + (keg->uk_rsize * i),
719 			    keg->uk_size);
720 	}
721 	if (keg->uk_flags & UMA_ZONE_VTOSLAB) {
722 		vm_object_t obj;
723 
724 		if (flags & UMA_SLAB_KMEM)
725 			obj = kmem_object;
726 		else if (flags & UMA_SLAB_KERNEL)
727 			obj = kernel_object;
728 		else
729 			obj = NULL;
730 		for (i = 0; i < keg->uk_ppera; i++)
731 			vsetobj((vm_offset_t)mem + (i * PAGE_SIZE), obj);
732 	}
733 	if (keg->uk_flags & UMA_ZONE_OFFPAGE)
734 		zone_free_item(keg->uk_slabzone, slab, NULL, SKIP_NONE);
735 #ifdef UMA_DEBUG
736 	printf("%s: Returning %d bytes.\n", keg->uk_name,
737 	    PAGE_SIZE * keg->uk_ppera);
738 #endif
739 	keg->uk_freef(mem, PAGE_SIZE * keg->uk_ppera, flags);
740 }
741 
742 /*
743  * Frees pages from a keg back to the system.  This is done on demand from
744  * the pageout daemon.
745  *
746  * Returns nothing.
747  */
748 static void
749 keg_drain(uma_keg_t keg)
750 {
751 	struct slabhead freeslabs = { 0 };
752 	uma_slab_t slab;
753 	uma_slab_t n;
754 
755 	/*
756 	 * We don't want to take pages from statically allocated kegs at this
757 	 * time
758 	 */
759 	if (keg->uk_flags & UMA_ZONE_NOFREE || keg->uk_freef == NULL)
760 		return;
761 
762 #ifdef UMA_DEBUG
763 	printf("%s free items: %u\n", keg->uk_name, keg->uk_free);
764 #endif
765 	KEG_LOCK(keg);
766 	if (keg->uk_free == 0)
767 		goto finished;
768 
769 	slab = LIST_FIRST(&keg->uk_free_slab);
770 	while (slab) {
771 		n = LIST_NEXT(slab, us_link);
772 
773 		/* We have no where to free these to */
774 		if (slab->us_flags & UMA_SLAB_BOOT) {
775 			slab = n;
776 			continue;
777 		}
778 
779 		LIST_REMOVE(slab, us_link);
780 		keg->uk_pages -= keg->uk_ppera;
781 		keg->uk_free -= keg->uk_ipers;
782 
783 		if (keg->uk_flags & UMA_ZONE_HASH)
784 			UMA_HASH_REMOVE(&keg->uk_hash, slab, slab->us_data);
785 
786 		SLIST_INSERT_HEAD(&freeslabs, slab, us_hlink);
787 
788 		slab = n;
789 	}
790 finished:
791 	KEG_UNLOCK(keg);
792 
793 	while ((slab = SLIST_FIRST(&freeslabs)) != NULL) {
794 		SLIST_REMOVE(&freeslabs, slab, uma_slab, us_hlink);
795 		keg_free_slab(keg, slab, 0);
796 	}
797 }
798 
799 static void
800 zone_drain_wait(uma_zone_t zone, int waitok)
801 {
802 
803 	/*
804 	 * Set draining to interlock with zone_dtor() so we can release our
805 	 * locks as we go.  Only dtor() should do a WAITOK call since it
806 	 * is the only call that knows the structure will still be available
807 	 * when it wakes up.
808 	 */
809 	ZONE_LOCK(zone);
810 	while (zone->uz_flags & UMA_ZFLAG_DRAINING) {
811 		if (waitok == M_NOWAIT)
812 			goto out;
813 		mtx_unlock(&uma_mtx);
814 		msleep(zone, zone->uz_lockptr, PVM, "zonedrain", 1);
815 		mtx_lock(&uma_mtx);
816 	}
817 	zone->uz_flags |= UMA_ZFLAG_DRAINING;
818 	bucket_cache_drain(zone);
819 	ZONE_UNLOCK(zone);
820 	/*
821 	 * The DRAINING flag protects us from being freed while
822 	 * we're running.  Normally the uma_mtx would protect us but we
823 	 * must be able to release and acquire the right lock for each keg.
824 	 */
825 	zone_foreach_keg(zone, &keg_drain);
826 	ZONE_LOCK(zone);
827 	zone->uz_flags &= ~UMA_ZFLAG_DRAINING;
828 	wakeup(zone);
829 out:
830 	ZONE_UNLOCK(zone);
831 }
832 
833 void
834 zone_drain(uma_zone_t zone)
835 {
836 
837 	zone_drain_wait(zone, M_NOWAIT);
838 }
839 
840 /*
841  * Allocate a new slab for a keg.  This does not insert the slab onto a list.
842  *
843  * Arguments:
844  *	wait  Shall we wait?
845  *
846  * Returns:
847  *	The slab that was allocated or NULL if there is no memory and the
848  *	caller specified M_NOWAIT.
849  */
850 static uma_slab_t
851 keg_alloc_slab(uma_keg_t keg, uma_zone_t zone, int wait)
852 {
853 	uma_slabrefcnt_t slabref;
854 	uma_alloc allocf;
855 	uma_slab_t slab;
856 	uint8_t *mem;
857 	uint8_t flags;
858 	int i;
859 
860 	mtx_assert(&keg->uk_lock, MA_OWNED);
861 	slab = NULL;
862 	mem = NULL;
863 
864 #ifdef UMA_DEBUG
865 	printf("alloc_slab:  Allocating a new slab for %s\n", keg->uk_name);
866 #endif
867 	allocf = keg->uk_allocf;
868 	KEG_UNLOCK(keg);
869 
870 	if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
871 		slab = zone_alloc_item(keg->uk_slabzone, NULL, wait);
872 		if (slab == NULL)
873 			goto out;
874 	}
875 
876 	/*
877 	 * This reproduces the old vm_zone behavior of zero filling pages the
878 	 * first time they are added to a zone.
879 	 *
880 	 * Malloced items are zeroed in uma_zalloc.
881 	 */
882 
883 	if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
884 		wait |= M_ZERO;
885 	else
886 		wait &= ~M_ZERO;
887 
888 	if (keg->uk_flags & UMA_ZONE_NODUMP)
889 		wait |= M_NODUMP;
890 
891 	/* zone is passed for legacy reasons. */
892 	mem = allocf(zone, keg->uk_ppera * PAGE_SIZE, &flags, wait);
893 	if (mem == NULL) {
894 		if (keg->uk_flags & UMA_ZONE_OFFPAGE)
895 			zone_free_item(keg->uk_slabzone, slab, NULL, SKIP_NONE);
896 		slab = NULL;
897 		goto out;
898 	}
899 
900 	/* Point the slab into the allocated memory */
901 	if (!(keg->uk_flags & UMA_ZONE_OFFPAGE))
902 		slab = (uma_slab_t )(mem + keg->uk_pgoff);
903 
904 	if (keg->uk_flags & UMA_ZONE_VTOSLAB)
905 		for (i = 0; i < keg->uk_ppera; i++)
906 			vsetslab((vm_offset_t)mem + (i * PAGE_SIZE), slab);
907 
908 	slab->us_keg = keg;
909 	slab->us_data = mem;
910 	slab->us_freecount = keg->uk_ipers;
911 	slab->us_flags = flags;
912 	BIT_FILL(SLAB_SETSIZE, &slab->us_free);
913 #ifdef INVARIANTS
914 	BIT_ZERO(SLAB_SETSIZE, &slab->us_debugfree);
915 #endif
916 	if (keg->uk_flags & UMA_ZONE_REFCNT) {
917 		slabref = (uma_slabrefcnt_t)slab;
918 		for (i = 0; i < keg->uk_ipers; i++)
919 			slabref->us_refcnt[i] = 0;
920 	}
921 
922 	if (keg->uk_init != NULL) {
923 		for (i = 0; i < keg->uk_ipers; i++)
924 			if (keg->uk_init(slab->us_data + (keg->uk_rsize * i),
925 			    keg->uk_size, wait) != 0)
926 				break;
927 		if (i != keg->uk_ipers) {
928 			keg_free_slab(keg, slab, i);
929 			slab = NULL;
930 			goto out;
931 		}
932 	}
933 out:
934 	KEG_LOCK(keg);
935 
936 	if (slab != NULL) {
937 		if (keg->uk_flags & UMA_ZONE_HASH)
938 			UMA_HASH_INSERT(&keg->uk_hash, slab, mem);
939 
940 		keg->uk_pages += keg->uk_ppera;
941 		keg->uk_free += keg->uk_ipers;
942 	}
943 
944 	return (slab);
945 }
946 
947 /*
948  * This function is intended to be used early on in place of page_alloc() so
949  * that we may use the boot time page cache to satisfy allocations before
950  * the VM is ready.
951  */
952 static void *
953 startup_alloc(uma_zone_t zone, int bytes, uint8_t *pflag, int wait)
954 {
955 	uma_keg_t keg;
956 	uma_slab_t tmps;
957 	int pages, check_pages;
958 
959 	keg = zone_first_keg(zone);
960 	pages = howmany(bytes, PAGE_SIZE);
961 	check_pages = pages - 1;
962 	KASSERT(pages > 0, ("startup_alloc can't reserve 0 pages\n"));
963 
964 	/*
965 	 * Check our small startup cache to see if it has pages remaining.
966 	 */
967 	mtx_lock(&uma_boot_pages_mtx);
968 
969 	/* First check if we have enough room. */
970 	tmps = LIST_FIRST(&uma_boot_pages);
971 	while (tmps != NULL && check_pages-- > 0)
972 		tmps = LIST_NEXT(tmps, us_link);
973 	if (tmps != NULL) {
974 		/*
975 		 * It's ok to lose tmps references.  The last one will
976 		 * have tmps->us_data pointing to the start address of
977 		 * "pages" contiguous pages of memory.
978 		 */
979 		while (pages-- > 0) {
980 			tmps = LIST_FIRST(&uma_boot_pages);
981 			LIST_REMOVE(tmps, us_link);
982 		}
983 		mtx_unlock(&uma_boot_pages_mtx);
984 		*pflag = tmps->us_flags;
985 		return (tmps->us_data);
986 	}
987 	mtx_unlock(&uma_boot_pages_mtx);
988 	if (booted < UMA_STARTUP2)
989 		panic("UMA: Increase vm.boot_pages");
990 	/*
991 	 * Now that we've booted reset these users to their real allocator.
992 	 */
993 #ifdef UMA_MD_SMALL_ALLOC
994 	keg->uk_allocf = (keg->uk_ppera > 1) ? page_alloc : uma_small_alloc;
995 #else
996 	keg->uk_allocf = page_alloc;
997 #endif
998 	return keg->uk_allocf(zone, bytes, pflag, wait);
999 }
1000 
1001 /*
1002  * Allocates a number of pages from the system
1003  *
1004  * Arguments:
1005  *	bytes  The number of bytes requested
1006  *	wait  Shall we wait?
1007  *
1008  * Returns:
1009  *	A pointer to the alloced memory or possibly
1010  *	NULL if M_NOWAIT is set.
1011  */
1012 static void *
1013 page_alloc(uma_zone_t zone, int bytes, uint8_t *pflag, int wait)
1014 {
1015 	void *p;	/* Returned page */
1016 
1017 	*pflag = UMA_SLAB_KMEM;
1018 	p = (void *) kmem_malloc(kmem_map, bytes, wait);
1019 
1020 	return (p);
1021 }
1022 
1023 /*
1024  * Allocates a number of pages from within an object
1025  *
1026  * Arguments:
1027  *	bytes  The number of bytes requested
1028  *	wait   Shall we wait?
1029  *
1030  * Returns:
1031  *	A pointer to the alloced memory or possibly
1032  *	NULL if M_NOWAIT is set.
1033  */
1034 static void *
1035 noobj_alloc(uma_zone_t zone, int bytes, uint8_t *flags, int wait)
1036 {
1037 	TAILQ_HEAD(, vm_page) alloctail;
1038 	u_long npages;
1039 	vm_offset_t retkva, zkva;
1040 	vm_page_t p, p_next;
1041 	uma_keg_t keg;
1042 
1043 	TAILQ_INIT(&alloctail);
1044 	keg = zone_first_keg(zone);
1045 
1046 	npages = howmany(bytes, PAGE_SIZE);
1047 	while (npages > 0) {
1048 		p = vm_page_alloc(NULL, 0, VM_ALLOC_INTERRUPT |
1049 		    VM_ALLOC_WIRED | VM_ALLOC_NOOBJ);
1050 		if (p != NULL) {
1051 			/*
1052 			 * Since the page does not belong to an object, its
1053 			 * listq is unused.
1054 			 */
1055 			TAILQ_INSERT_TAIL(&alloctail, p, listq);
1056 			npages--;
1057 			continue;
1058 		}
1059 		if (wait & M_WAITOK) {
1060 			VM_WAIT;
1061 			continue;
1062 		}
1063 
1064 		/*
1065 		 * Page allocation failed, free intermediate pages and
1066 		 * exit.
1067 		 */
1068 		TAILQ_FOREACH_SAFE(p, &alloctail, listq, p_next) {
1069 			vm_page_unwire(p, 0);
1070 			vm_page_free(p);
1071 		}
1072 		return (NULL);
1073 	}
1074 	*flags = UMA_SLAB_PRIV;
1075 	zkva = keg->uk_kva +
1076 	    atomic_fetchadd_long(&keg->uk_offset, round_page(bytes));
1077 	retkva = zkva;
1078 	TAILQ_FOREACH(p, &alloctail, listq) {
1079 		pmap_qenter(zkva, &p, 1);
1080 		zkva += PAGE_SIZE;
1081 	}
1082 
1083 	return ((void *)retkva);
1084 }
1085 
1086 /*
1087  * Frees a number of pages to the system
1088  *
1089  * Arguments:
1090  *	mem   A pointer to the memory to be freed
1091  *	size  The size of the memory being freed
1092  *	flags The original p->us_flags field
1093  *
1094  * Returns:
1095  *	Nothing
1096  */
1097 static void
1098 page_free(void *mem, int size, uint8_t flags)
1099 {
1100 	vm_map_t map;
1101 
1102 	if (flags & UMA_SLAB_KMEM)
1103 		map = kmem_map;
1104 	else if (flags & UMA_SLAB_KERNEL)
1105 		map = kernel_map;
1106 	else
1107 		panic("UMA: page_free used with invalid flags %d", flags);
1108 
1109 	kmem_free(map, (vm_offset_t)mem, size);
1110 }
1111 
1112 /*
1113  * Zero fill initializer
1114  *
1115  * Arguments/Returns follow uma_init specifications
1116  */
1117 static int
1118 zero_init(void *mem, int size, int flags)
1119 {
1120 	bzero(mem, size);
1121 	return (0);
1122 }
1123 
1124 /*
1125  * Finish creating a small uma keg.  This calculates ipers, and the keg size.
1126  *
1127  * Arguments
1128  *	keg  The zone we should initialize
1129  *
1130  * Returns
1131  *	Nothing
1132  */
1133 static void
1134 keg_small_init(uma_keg_t keg)
1135 {
1136 	u_int rsize;
1137 	u_int memused;
1138 	u_int wastedspace;
1139 	u_int shsize;
1140 
1141 	if (keg->uk_flags & UMA_ZONE_PCPU) {
1142 		u_int ncpus = mp_ncpus ? mp_ncpus : MAXCPU;
1143 
1144 		keg->uk_slabsize = sizeof(struct pcpu);
1145 		keg->uk_ppera = howmany(ncpus * sizeof(struct pcpu),
1146 		    PAGE_SIZE);
1147 	} else {
1148 		keg->uk_slabsize = UMA_SLAB_SIZE;
1149 		keg->uk_ppera = 1;
1150 	}
1151 
1152 	/*
1153 	 * Calculate the size of each allocation (rsize) according to
1154 	 * alignment.  If the requested size is smaller than we have
1155 	 * allocation bits for we round it up.
1156 	 */
1157 	rsize = keg->uk_size;
1158 	if (rsize < keg->uk_slabsize / SLAB_SETSIZE)
1159 		rsize = keg->uk_slabsize / SLAB_SETSIZE;
1160 	if (rsize & keg->uk_align)
1161 		rsize = (rsize & ~keg->uk_align) + (keg->uk_align + 1);
1162 	keg->uk_rsize = rsize;
1163 
1164 	KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0 ||
1165 	    keg->uk_rsize < sizeof(struct pcpu),
1166 	    ("%s: size %u too large", __func__, keg->uk_rsize));
1167 
1168 	if (keg->uk_flags & UMA_ZONE_REFCNT)
1169 		rsize += sizeof(uint32_t);
1170 
1171 	if (keg->uk_flags & UMA_ZONE_OFFPAGE)
1172 		shsize = 0;
1173 	else
1174 		shsize = sizeof(struct uma_slab);
1175 
1176 	keg->uk_ipers = (keg->uk_slabsize - shsize) / rsize;
1177 	KASSERT(keg->uk_ipers > 0 && keg->uk_ipers <= SLAB_SETSIZE,
1178 	    ("%s: keg->uk_ipers %u", __func__, keg->uk_ipers));
1179 
1180 	memused = keg->uk_ipers * rsize + shsize;
1181 	wastedspace = keg->uk_slabsize - memused;
1182 
1183 	/*
1184 	 * We can't do OFFPAGE if we're internal or if we've been
1185 	 * asked to not go to the VM for buckets.  If we do this we
1186 	 * may end up going to the VM  for slabs which we do not
1187 	 * want to do if we're UMA_ZFLAG_CACHEONLY as a result
1188 	 * of UMA_ZONE_VM, which clearly forbids it.
1189 	 */
1190 	if ((keg->uk_flags & UMA_ZFLAG_INTERNAL) ||
1191 	    (keg->uk_flags & UMA_ZFLAG_CACHEONLY))
1192 		return;
1193 
1194 	/*
1195 	 * See if using an OFFPAGE slab will limit our waste.  Only do
1196 	 * this if it permits more items per-slab.
1197 	 *
1198 	 * XXX We could try growing slabsize to limit max waste as well.
1199 	 * Historically this was not done because the VM could not
1200 	 * efficiently handle contiguous allocations.
1201 	 */
1202 	if ((wastedspace >= keg->uk_slabsize / UMA_MAX_WASTE) &&
1203 	    (keg->uk_ipers < (keg->uk_slabsize / keg->uk_rsize))) {
1204 		keg->uk_ipers = keg->uk_slabsize / keg->uk_rsize;
1205 		KASSERT(keg->uk_ipers > 0 && keg->uk_ipers <= SLAB_SETSIZE,
1206 		    ("%s: keg->uk_ipers %u", __func__, keg->uk_ipers));
1207 #ifdef UMA_DEBUG
1208 		printf("UMA decided we need offpage slab headers for "
1209 		    "keg: %s, calculated wastedspace = %d, "
1210 		    "maximum wasted space allowed = %d, "
1211 		    "calculated ipers = %d, "
1212 		    "new wasted space = %d\n", keg->uk_name, wastedspace,
1213 		    keg->uk_slabsize / UMA_MAX_WASTE, keg->uk_ipers,
1214 		    keg->uk_slabsize - keg->uk_ipers * keg->uk_rsize);
1215 #endif
1216 		keg->uk_flags |= UMA_ZONE_OFFPAGE;
1217 	}
1218 
1219 	if ((keg->uk_flags & UMA_ZONE_OFFPAGE) &&
1220 	    (keg->uk_flags & UMA_ZONE_VTOSLAB) == 0)
1221 		keg->uk_flags |= UMA_ZONE_HASH;
1222 }
1223 
1224 /*
1225  * Finish creating a large (> UMA_SLAB_SIZE) uma kegs.  Just give in and do
1226  * OFFPAGE for now.  When I can allow for more dynamic slab sizes this will be
1227  * more complicated.
1228  *
1229  * Arguments
1230  *	keg  The keg we should initialize
1231  *
1232  * Returns
1233  *	Nothing
1234  */
1235 static void
1236 keg_large_init(uma_keg_t keg)
1237 {
1238 
1239 	KASSERT(keg != NULL, ("Keg is null in keg_large_init"));
1240 	KASSERT((keg->uk_flags & UMA_ZFLAG_CACHEONLY) == 0,
1241 	    ("keg_large_init: Cannot large-init a UMA_ZFLAG_CACHEONLY keg"));
1242 	KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0,
1243 	    ("%s: Cannot large-init a UMA_ZONE_PCPU keg", __func__));
1244 
1245 	keg->uk_ppera = howmany(keg->uk_size, PAGE_SIZE);
1246 	keg->uk_slabsize = keg->uk_ppera * PAGE_SIZE;
1247 	keg->uk_ipers = 1;
1248 	keg->uk_rsize = keg->uk_size;
1249 
1250 	/* We can't do OFFPAGE if we're internal, bail out here. */
1251 	if (keg->uk_flags & UMA_ZFLAG_INTERNAL)
1252 		return;
1253 
1254 	keg->uk_flags |= UMA_ZONE_OFFPAGE;
1255 	if ((keg->uk_flags & UMA_ZONE_VTOSLAB) == 0)
1256 		keg->uk_flags |= UMA_ZONE_HASH;
1257 }
1258 
1259 static void
1260 keg_cachespread_init(uma_keg_t keg)
1261 {
1262 	int alignsize;
1263 	int trailer;
1264 	int pages;
1265 	int rsize;
1266 
1267 	KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0,
1268 	    ("%s: Cannot cachespread-init a UMA_ZONE_PCPU keg", __func__));
1269 
1270 	alignsize = keg->uk_align + 1;
1271 	rsize = keg->uk_size;
1272 	/*
1273 	 * We want one item to start on every align boundary in a page.  To
1274 	 * do this we will span pages.  We will also extend the item by the
1275 	 * size of align if it is an even multiple of align.  Otherwise, it
1276 	 * would fall on the same boundary every time.
1277 	 */
1278 	if (rsize & keg->uk_align)
1279 		rsize = (rsize & ~keg->uk_align) + alignsize;
1280 	if ((rsize & alignsize) == 0)
1281 		rsize += alignsize;
1282 	trailer = rsize - keg->uk_size;
1283 	pages = (rsize * (PAGE_SIZE / alignsize)) / PAGE_SIZE;
1284 	pages = MIN(pages, (128 * 1024) / PAGE_SIZE);
1285 	keg->uk_rsize = rsize;
1286 	keg->uk_ppera = pages;
1287 	keg->uk_slabsize = UMA_SLAB_SIZE;
1288 	keg->uk_ipers = ((pages * PAGE_SIZE) + trailer) / rsize;
1289 	keg->uk_flags |= UMA_ZONE_OFFPAGE | UMA_ZONE_VTOSLAB;
1290 	KASSERT(keg->uk_ipers <= uma_max_ipers,
1291 	    ("%s: keg->uk_ipers too high(%d) increase max_ipers", __func__,
1292 	    keg->uk_ipers));
1293 }
1294 
1295 /*
1296  * Keg header ctor.  This initializes all fields, locks, etc.  And inserts
1297  * the keg onto the global keg list.
1298  *
1299  * Arguments/Returns follow uma_ctor specifications
1300  *	udata  Actually uma_kctor_args
1301  */
1302 static int
1303 keg_ctor(void *mem, int size, void *udata, int flags)
1304 {
1305 	struct uma_kctor_args *arg = udata;
1306 	uma_keg_t keg = mem;
1307 	uma_zone_t zone;
1308 
1309 	bzero(keg, size);
1310 	keg->uk_size = arg->size;
1311 	keg->uk_init = arg->uminit;
1312 	keg->uk_fini = arg->fini;
1313 	keg->uk_align = arg->align;
1314 	keg->uk_free = 0;
1315 	keg->uk_reserve = 0;
1316 	keg->uk_pages = 0;
1317 	keg->uk_flags = arg->flags;
1318 	keg->uk_allocf = page_alloc;
1319 	keg->uk_freef = page_free;
1320 	keg->uk_slabzone = NULL;
1321 
1322 	/*
1323 	 * The master zone is passed to us at keg-creation time.
1324 	 */
1325 	zone = arg->zone;
1326 	keg->uk_name = zone->uz_name;
1327 
1328 	if (arg->flags & UMA_ZONE_VM)
1329 		keg->uk_flags |= UMA_ZFLAG_CACHEONLY;
1330 
1331 	if (arg->flags & UMA_ZONE_ZINIT)
1332 		keg->uk_init = zero_init;
1333 
1334 	if (arg->flags & UMA_ZONE_REFCNT || arg->flags & UMA_ZONE_MALLOC)
1335 		keg->uk_flags |= UMA_ZONE_VTOSLAB;
1336 
1337 	if (arg->flags & UMA_ZONE_PCPU)
1338 #ifdef SMP
1339 		keg->uk_flags |= UMA_ZONE_OFFPAGE;
1340 #else
1341 		keg->uk_flags &= ~UMA_ZONE_PCPU;
1342 #endif
1343 
1344 	if (keg->uk_flags & UMA_ZONE_CACHESPREAD) {
1345 		keg_cachespread_init(keg);
1346 	} else if (keg->uk_flags & UMA_ZONE_REFCNT) {
1347 		if (keg->uk_size >
1348 		    (UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt) -
1349 		    sizeof(uint32_t)))
1350 			keg_large_init(keg);
1351 		else
1352 			keg_small_init(keg);
1353 	} else {
1354 		if (keg->uk_size > (UMA_SLAB_SIZE - sizeof(struct uma_slab)))
1355 			keg_large_init(keg);
1356 		else
1357 			keg_small_init(keg);
1358 	}
1359 
1360 	if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
1361 		if (keg->uk_flags & UMA_ZONE_REFCNT) {
1362 			if (keg->uk_ipers > uma_max_ipers_ref)
1363 				panic("Too many ref items per zone: %d > %d\n",
1364 				    keg->uk_ipers, uma_max_ipers_ref);
1365 			keg->uk_slabzone = slabrefzone;
1366 		} else
1367 			keg->uk_slabzone = slabzone;
1368 	}
1369 
1370 	/*
1371 	 * If we haven't booted yet we need allocations to go through the
1372 	 * startup cache until the vm is ready.
1373 	 */
1374 	if (keg->uk_ppera == 1) {
1375 #ifdef UMA_MD_SMALL_ALLOC
1376 		keg->uk_allocf = uma_small_alloc;
1377 		keg->uk_freef = uma_small_free;
1378 
1379 		if (booted < UMA_STARTUP)
1380 			keg->uk_allocf = startup_alloc;
1381 #else
1382 		if (booted < UMA_STARTUP2)
1383 			keg->uk_allocf = startup_alloc;
1384 #endif
1385 	} else if (booted < UMA_STARTUP2 &&
1386 	    (keg->uk_flags & UMA_ZFLAG_INTERNAL))
1387 		keg->uk_allocf = startup_alloc;
1388 
1389 	/*
1390 	 * Initialize keg's lock
1391 	 */
1392 	KEG_LOCK_INIT(keg, (arg->flags & UMA_ZONE_MTXCLASS));
1393 
1394 	/*
1395 	 * If we're putting the slab header in the actual page we need to
1396 	 * figure out where in each page it goes.  This calculates a right
1397 	 * justified offset into the memory on an ALIGN_PTR boundary.
1398 	 */
1399 	if (!(keg->uk_flags & UMA_ZONE_OFFPAGE)) {
1400 		u_int totsize;
1401 
1402 		/* Size of the slab struct and free list */
1403 		totsize = sizeof(struct uma_slab);
1404 
1405 		/* Size of the reference counts. */
1406 		if (keg->uk_flags & UMA_ZONE_REFCNT)
1407 			totsize += keg->uk_ipers * sizeof(uint32_t);
1408 
1409 		if (totsize & UMA_ALIGN_PTR)
1410 			totsize = (totsize & ~UMA_ALIGN_PTR) +
1411 			    (UMA_ALIGN_PTR + 1);
1412 		keg->uk_pgoff = (PAGE_SIZE * keg->uk_ppera) - totsize;
1413 
1414 		/*
1415 		 * The only way the following is possible is if with our
1416 		 * UMA_ALIGN_PTR adjustments we are now bigger than
1417 		 * UMA_SLAB_SIZE.  I haven't checked whether this is
1418 		 * mathematically possible for all cases, so we make
1419 		 * sure here anyway.
1420 		 */
1421 		totsize = keg->uk_pgoff + sizeof(struct uma_slab);
1422 		if (keg->uk_flags & UMA_ZONE_REFCNT)
1423 			totsize += keg->uk_ipers * sizeof(uint32_t);
1424 		if (totsize > PAGE_SIZE * keg->uk_ppera) {
1425 			printf("zone %s ipers %d rsize %d size %d\n",
1426 			    zone->uz_name, keg->uk_ipers, keg->uk_rsize,
1427 			    keg->uk_size);
1428 			panic("UMA slab won't fit.");
1429 		}
1430 	}
1431 
1432 	if (keg->uk_flags & UMA_ZONE_HASH)
1433 		hash_alloc(&keg->uk_hash);
1434 
1435 #ifdef UMA_DEBUG
1436 	printf("UMA: %s(%p) size %d(%d) flags %#x ipers %d ppera %d out %d free %d\n",
1437 	    zone->uz_name, zone, keg->uk_size, keg->uk_rsize, keg->uk_flags,
1438 	    keg->uk_ipers, keg->uk_ppera,
1439 	    (keg->uk_ipers * keg->uk_pages) - keg->uk_free, keg->uk_free);
1440 #endif
1441 
1442 	LIST_INSERT_HEAD(&keg->uk_zones, zone, uz_link);
1443 
1444 	mtx_lock(&uma_mtx);
1445 	LIST_INSERT_HEAD(&uma_kegs, keg, uk_link);
1446 	mtx_unlock(&uma_mtx);
1447 	return (0);
1448 }
1449 
1450 /*
1451  * Zone header ctor.  This initializes all fields, locks, etc.
1452  *
1453  * Arguments/Returns follow uma_ctor specifications
1454  *	udata  Actually uma_zctor_args
1455  */
1456 static int
1457 zone_ctor(void *mem, int size, void *udata, int flags)
1458 {
1459 	struct uma_zctor_args *arg = udata;
1460 	uma_zone_t zone = mem;
1461 	uma_zone_t z;
1462 	uma_keg_t keg;
1463 
1464 	bzero(zone, size);
1465 	zone->uz_name = arg->name;
1466 	zone->uz_ctor = arg->ctor;
1467 	zone->uz_dtor = arg->dtor;
1468 	zone->uz_slab = zone_fetch_slab;
1469 	zone->uz_init = NULL;
1470 	zone->uz_fini = NULL;
1471 	zone->uz_allocs = 0;
1472 	zone->uz_frees = 0;
1473 	zone->uz_fails = 0;
1474 	zone->uz_sleeps = 0;
1475 	zone->uz_count = 0;
1476 	zone->uz_flags = 0;
1477 	zone->uz_warning = NULL;
1478 	timevalclear(&zone->uz_ratecheck);
1479 	keg = arg->keg;
1480 
1481 	ZONE_LOCK_INIT(zone, (arg->flags & UMA_ZONE_MTXCLASS));
1482 
1483 	/*
1484 	 * This is a pure cache zone, no kegs.
1485 	 */
1486 	if (arg->import) {
1487 		if (arg->flags & UMA_ZONE_VM)
1488 			arg->flags |= UMA_ZFLAG_CACHEONLY;
1489 		zone->uz_flags = arg->flags;
1490 		zone->uz_size = arg->size;
1491 		zone->uz_import = arg->import;
1492 		zone->uz_release = arg->release;
1493 		zone->uz_arg = arg->arg;
1494 		zone->uz_lockptr = &zone->uz_lock;
1495 		goto out;
1496 	}
1497 
1498 	/*
1499 	 * Use the regular zone/keg/slab allocator.
1500 	 */
1501 	zone->uz_import = (uma_import)zone_import;
1502 	zone->uz_release = (uma_release)zone_release;
1503 	zone->uz_arg = zone;
1504 
1505 	if (arg->flags & UMA_ZONE_SECONDARY) {
1506 		KASSERT(arg->keg != NULL, ("Secondary zone on zero'd keg"));
1507 		zone->uz_init = arg->uminit;
1508 		zone->uz_fini = arg->fini;
1509 		zone->uz_lockptr = &keg->uk_lock;
1510 		zone->uz_flags |= UMA_ZONE_SECONDARY;
1511 		mtx_lock(&uma_mtx);
1512 		ZONE_LOCK(zone);
1513 		LIST_FOREACH(z, &keg->uk_zones, uz_link) {
1514 			if (LIST_NEXT(z, uz_link) == NULL) {
1515 				LIST_INSERT_AFTER(z, zone, uz_link);
1516 				break;
1517 			}
1518 		}
1519 		ZONE_UNLOCK(zone);
1520 		mtx_unlock(&uma_mtx);
1521 	} else if (keg == NULL) {
1522 		if ((keg = uma_kcreate(zone, arg->size, arg->uminit, arg->fini,
1523 		    arg->align, arg->flags)) == NULL)
1524 			return (ENOMEM);
1525 	} else {
1526 		struct uma_kctor_args karg;
1527 		int error;
1528 
1529 		/* We should only be here from uma_startup() */
1530 		karg.size = arg->size;
1531 		karg.uminit = arg->uminit;
1532 		karg.fini = arg->fini;
1533 		karg.align = arg->align;
1534 		karg.flags = arg->flags;
1535 		karg.zone = zone;
1536 		error = keg_ctor(arg->keg, sizeof(struct uma_keg), &karg,
1537 		    flags);
1538 		if (error)
1539 			return (error);
1540 	}
1541 
1542 	/*
1543 	 * Link in the first keg.
1544 	 */
1545 	zone->uz_klink.kl_keg = keg;
1546 	LIST_INSERT_HEAD(&zone->uz_kegs, &zone->uz_klink, kl_link);
1547 	zone->uz_lockptr = &keg->uk_lock;
1548 	zone->uz_size = keg->uk_size;
1549 	zone->uz_flags |= (keg->uk_flags &
1550 	    (UMA_ZONE_INHERIT | UMA_ZFLAG_INHERIT));
1551 
1552 	/*
1553 	 * Some internal zones don't have room allocated for the per cpu
1554 	 * caches.  If we're internal, bail out here.
1555 	 */
1556 	if (keg->uk_flags & UMA_ZFLAG_INTERNAL) {
1557 		KASSERT((zone->uz_flags & UMA_ZONE_SECONDARY) == 0,
1558 		    ("Secondary zone requested UMA_ZFLAG_INTERNAL"));
1559 		return (0);
1560 	}
1561 
1562 out:
1563 	if ((arg->flags & UMA_ZONE_MAXBUCKET) == 0)
1564 		zone->uz_count = bucket_select(zone->uz_size);
1565 	else
1566 		zone->uz_count = BUCKET_MAX;
1567 
1568 	return (0);
1569 }
1570 
1571 /*
1572  * Keg header dtor.  This frees all data, destroys locks, frees the hash
1573  * table and removes the keg from the global list.
1574  *
1575  * Arguments/Returns follow uma_dtor specifications
1576  *	udata  unused
1577  */
1578 static void
1579 keg_dtor(void *arg, int size, void *udata)
1580 {
1581 	uma_keg_t keg;
1582 
1583 	keg = (uma_keg_t)arg;
1584 	KEG_LOCK(keg);
1585 	if (keg->uk_free != 0) {
1586 		printf("Freed UMA keg was not empty (%d items). "
1587 		    " Lost %d pages of memory.\n",
1588 		    keg->uk_free, keg->uk_pages);
1589 	}
1590 	KEG_UNLOCK(keg);
1591 
1592 	hash_free(&keg->uk_hash);
1593 
1594 	KEG_LOCK_FINI(keg);
1595 }
1596 
1597 /*
1598  * Zone header dtor.
1599  *
1600  * Arguments/Returns follow uma_dtor specifications
1601  *	udata  unused
1602  */
1603 static void
1604 zone_dtor(void *arg, int size, void *udata)
1605 {
1606 	uma_klink_t klink;
1607 	uma_zone_t zone;
1608 	uma_keg_t keg;
1609 
1610 	zone = (uma_zone_t)arg;
1611 	keg = zone_first_keg(zone);
1612 
1613 	if (!(zone->uz_flags & UMA_ZFLAG_INTERNAL))
1614 		cache_drain(zone);
1615 
1616 	mtx_lock(&uma_mtx);
1617 	LIST_REMOVE(zone, uz_link);
1618 	mtx_unlock(&uma_mtx);
1619 	/*
1620 	 * XXX there are some races here where
1621 	 * the zone can be drained but zone lock
1622 	 * released and then refilled before we
1623 	 * remove it... we dont care for now
1624 	 */
1625 	zone_drain_wait(zone, M_WAITOK);
1626 	/*
1627 	 * Unlink all of our kegs.
1628 	 */
1629 	while ((klink = LIST_FIRST(&zone->uz_kegs)) != NULL) {
1630 		klink->kl_keg = NULL;
1631 		LIST_REMOVE(klink, kl_link);
1632 		if (klink == &zone->uz_klink)
1633 			continue;
1634 		free(klink, M_TEMP);
1635 	}
1636 	/*
1637 	 * We only destroy kegs from non secondary zones.
1638 	 */
1639 	if (keg != NULL && (zone->uz_flags & UMA_ZONE_SECONDARY) == 0)  {
1640 		mtx_lock(&uma_mtx);
1641 		LIST_REMOVE(keg, uk_link);
1642 		mtx_unlock(&uma_mtx);
1643 		zone_free_item(kegs, keg, NULL, SKIP_NONE);
1644 	}
1645 	ZONE_LOCK_FINI(zone);
1646 }
1647 
1648 /*
1649  * Traverses every zone in the system and calls a callback
1650  *
1651  * Arguments:
1652  *	zfunc  A pointer to a function which accepts a zone
1653  *		as an argument.
1654  *
1655  * Returns:
1656  *	Nothing
1657  */
1658 static void
1659 zone_foreach(void (*zfunc)(uma_zone_t))
1660 {
1661 	uma_keg_t keg;
1662 	uma_zone_t zone;
1663 
1664 	mtx_lock(&uma_mtx);
1665 	LIST_FOREACH(keg, &uma_kegs, uk_link) {
1666 		LIST_FOREACH(zone, &keg->uk_zones, uz_link)
1667 			zfunc(zone);
1668 	}
1669 	mtx_unlock(&uma_mtx);
1670 }
1671 
1672 /* Public functions */
1673 /* See uma.h */
1674 void
1675 uma_startup(void *bootmem, int boot_pages)
1676 {
1677 	struct uma_zctor_args args;
1678 	uma_slab_t slab;
1679 	u_int slabsize;
1680 	int i;
1681 
1682 #ifdef UMA_DEBUG
1683 	printf("Creating uma keg headers zone and keg.\n");
1684 #endif
1685 	mtx_init(&uma_mtx, "UMA lock", NULL, MTX_DEF);
1686 
1687 	/* "manually" create the initial zone */
1688 	memset(&args, 0, sizeof(args));
1689 	args.name = "UMA Kegs";
1690 	args.size = sizeof(struct uma_keg);
1691 	args.ctor = keg_ctor;
1692 	args.dtor = keg_dtor;
1693 	args.uminit = zero_init;
1694 	args.fini = NULL;
1695 	args.keg = &masterkeg;
1696 	args.align = 32 - 1;
1697 	args.flags = UMA_ZFLAG_INTERNAL;
1698 	/* The initial zone has no Per cpu queues so it's smaller */
1699 	zone_ctor(kegs, sizeof(struct uma_zone), &args, M_WAITOK);
1700 
1701 #ifdef UMA_DEBUG
1702 	printf("Filling boot free list.\n");
1703 #endif
1704 	for (i = 0; i < boot_pages; i++) {
1705 		slab = (uma_slab_t)((uint8_t *)bootmem + (i * UMA_SLAB_SIZE));
1706 		slab->us_data = (uint8_t *)slab;
1707 		slab->us_flags = UMA_SLAB_BOOT;
1708 		LIST_INSERT_HEAD(&uma_boot_pages, slab, us_link);
1709 	}
1710 	mtx_init(&uma_boot_pages_mtx, "UMA boot pages", NULL, MTX_DEF);
1711 
1712 #ifdef UMA_DEBUG
1713 	printf("Creating uma zone headers zone and keg.\n");
1714 #endif
1715 	args.name = "UMA Zones";
1716 	args.size = sizeof(struct uma_zone) +
1717 	    (sizeof(struct uma_cache) * (mp_maxid + 1));
1718 	args.ctor = zone_ctor;
1719 	args.dtor = zone_dtor;
1720 	args.uminit = zero_init;
1721 	args.fini = NULL;
1722 	args.keg = NULL;
1723 	args.align = 32 - 1;
1724 	args.flags = UMA_ZFLAG_INTERNAL;
1725 	/* The initial zone has no Per cpu queues so it's smaller */
1726 	zone_ctor(zones, sizeof(struct uma_zone), &args, M_WAITOK);
1727 
1728 #ifdef UMA_DEBUG
1729 	printf("Initializing pcpu cache locks.\n");
1730 #endif
1731 #ifdef UMA_DEBUG
1732 	printf("Creating slab and hash zones.\n");
1733 #endif
1734 
1735 	/* Now make a zone for slab headers */
1736 	slabzone = uma_zcreate("UMA Slabs",
1737 				sizeof(struct uma_slab),
1738 				NULL, NULL, NULL, NULL,
1739 				UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
1740 
1741 	/*
1742 	 * We also create a zone for the bigger slabs with reference
1743 	 * counts in them, to accomodate UMA_ZONE_REFCNT zones.
1744 	 */
1745 	slabsize = sizeof(struct uma_slab_refcnt);
1746 	slabsize += uma_max_ipers_ref * sizeof(uint32_t);
1747 	slabrefzone = uma_zcreate("UMA RCntSlabs",
1748 				  slabsize,
1749 				  NULL, NULL, NULL, NULL,
1750 				  UMA_ALIGN_PTR,
1751 				  UMA_ZFLAG_INTERNAL);
1752 
1753 	hashzone = uma_zcreate("UMA Hash",
1754 	    sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT,
1755 	    NULL, NULL, NULL, NULL,
1756 	    UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
1757 
1758 	bucket_init();
1759 
1760 	booted = UMA_STARTUP;
1761 
1762 #ifdef UMA_DEBUG
1763 	printf("UMA startup complete.\n");
1764 #endif
1765 }
1766 
1767 /* see uma.h */
1768 void
1769 uma_startup2(void)
1770 {
1771 	booted = UMA_STARTUP2;
1772 	bucket_enable();
1773 #ifdef UMA_DEBUG
1774 	printf("UMA startup2 complete.\n");
1775 #endif
1776 }
1777 
1778 /*
1779  * Initialize our callout handle
1780  *
1781  */
1782 
1783 static void
1784 uma_startup3(void)
1785 {
1786 #ifdef UMA_DEBUG
1787 	printf("Starting callout.\n");
1788 #endif
1789 	callout_init(&uma_callout, CALLOUT_MPSAFE);
1790 	callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
1791 #ifdef UMA_DEBUG
1792 	printf("UMA startup3 complete.\n");
1793 #endif
1794 }
1795 
1796 static uma_keg_t
1797 uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini,
1798 		int align, uint32_t flags)
1799 {
1800 	struct uma_kctor_args args;
1801 
1802 	args.size = size;
1803 	args.uminit = uminit;
1804 	args.fini = fini;
1805 	args.align = (align == UMA_ALIGN_CACHE) ? uma_align_cache : align;
1806 	args.flags = flags;
1807 	args.zone = zone;
1808 	return (zone_alloc_item(kegs, &args, M_WAITOK));
1809 }
1810 
1811 /* See uma.h */
1812 void
1813 uma_set_align(int align)
1814 {
1815 
1816 	if (align != UMA_ALIGN_CACHE)
1817 		uma_align_cache = align;
1818 }
1819 
1820 /* See uma.h */
1821 uma_zone_t
1822 uma_zcreate(const char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
1823 		uma_init uminit, uma_fini fini, int align, uint32_t flags)
1824 
1825 {
1826 	struct uma_zctor_args args;
1827 
1828 	/* This stuff is essential for the zone ctor */
1829 	memset(&args, 0, sizeof(args));
1830 	args.name = name;
1831 	args.size = size;
1832 	args.ctor = ctor;
1833 	args.dtor = dtor;
1834 	args.uminit = uminit;
1835 	args.fini = fini;
1836 	args.align = align;
1837 	args.flags = flags;
1838 	args.keg = NULL;
1839 
1840 	return (zone_alloc_item(zones, &args, M_WAITOK));
1841 }
1842 
1843 /* See uma.h */
1844 uma_zone_t
1845 uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
1846 		    uma_init zinit, uma_fini zfini, uma_zone_t master)
1847 {
1848 	struct uma_zctor_args args;
1849 	uma_keg_t keg;
1850 
1851 	keg = zone_first_keg(master);
1852 	memset(&args, 0, sizeof(args));
1853 	args.name = name;
1854 	args.size = keg->uk_size;
1855 	args.ctor = ctor;
1856 	args.dtor = dtor;
1857 	args.uminit = zinit;
1858 	args.fini = zfini;
1859 	args.align = keg->uk_align;
1860 	args.flags = keg->uk_flags | UMA_ZONE_SECONDARY;
1861 	args.keg = keg;
1862 
1863 	/* XXX Attaches only one keg of potentially many. */
1864 	return (zone_alloc_item(zones, &args, M_WAITOK));
1865 }
1866 
1867 /* See uma.h */
1868 uma_zone_t
1869 uma_zcache_create(char *name, int size, uma_ctor ctor, uma_dtor dtor,
1870 		    uma_init zinit, uma_fini zfini, uma_import zimport,
1871 		    uma_release zrelease, void *arg, int flags)
1872 {
1873 	struct uma_zctor_args args;
1874 
1875 	memset(&args, 0, sizeof(args));
1876 	args.name = name;
1877 	args.size = size;
1878 	args.ctor = ctor;
1879 	args.dtor = dtor;
1880 	args.uminit = zinit;
1881 	args.fini = zfini;
1882 	args.import = zimport;
1883 	args.release = zrelease;
1884 	args.arg = arg;
1885 	args.align = 0;
1886 	args.flags = flags;
1887 
1888 	return (zone_alloc_item(zones, &args, M_WAITOK));
1889 }
1890 
1891 static void
1892 zone_lock_pair(uma_zone_t a, uma_zone_t b)
1893 {
1894 	if (a < b) {
1895 		ZONE_LOCK(a);
1896 		mtx_lock_flags(b->uz_lockptr, MTX_DUPOK);
1897 	} else {
1898 		ZONE_LOCK(b);
1899 		mtx_lock_flags(a->uz_lockptr, MTX_DUPOK);
1900 	}
1901 }
1902 
1903 static void
1904 zone_unlock_pair(uma_zone_t a, uma_zone_t b)
1905 {
1906 
1907 	ZONE_UNLOCK(a);
1908 	ZONE_UNLOCK(b);
1909 }
1910 
1911 int
1912 uma_zsecond_add(uma_zone_t zone, uma_zone_t master)
1913 {
1914 	uma_klink_t klink;
1915 	uma_klink_t kl;
1916 	int error;
1917 
1918 	error = 0;
1919 	klink = malloc(sizeof(*klink), M_TEMP, M_WAITOK | M_ZERO);
1920 
1921 	zone_lock_pair(zone, master);
1922 	/*
1923 	 * zone must use vtoslab() to resolve objects and must already be
1924 	 * a secondary.
1925 	 */
1926 	if ((zone->uz_flags & (UMA_ZONE_VTOSLAB | UMA_ZONE_SECONDARY))
1927 	    != (UMA_ZONE_VTOSLAB | UMA_ZONE_SECONDARY)) {
1928 		error = EINVAL;
1929 		goto out;
1930 	}
1931 	/*
1932 	 * The new master must also use vtoslab().
1933 	 */
1934 	if ((zone->uz_flags & UMA_ZONE_VTOSLAB) != UMA_ZONE_VTOSLAB) {
1935 		error = EINVAL;
1936 		goto out;
1937 	}
1938 	/*
1939 	 * Both must either be refcnt, or not be refcnt.
1940 	 */
1941 	if ((zone->uz_flags & UMA_ZONE_REFCNT) !=
1942 	    (master->uz_flags & UMA_ZONE_REFCNT)) {
1943 		error = EINVAL;
1944 		goto out;
1945 	}
1946 	/*
1947 	 * The underlying object must be the same size.  rsize
1948 	 * may be different.
1949 	 */
1950 	if (master->uz_size != zone->uz_size) {
1951 		error = E2BIG;
1952 		goto out;
1953 	}
1954 	/*
1955 	 * Put it at the end of the list.
1956 	 */
1957 	klink->kl_keg = zone_first_keg(master);
1958 	LIST_FOREACH(kl, &zone->uz_kegs, kl_link) {
1959 		if (LIST_NEXT(kl, kl_link) == NULL) {
1960 			LIST_INSERT_AFTER(kl, klink, kl_link);
1961 			break;
1962 		}
1963 	}
1964 	klink = NULL;
1965 	zone->uz_flags |= UMA_ZFLAG_MULTI;
1966 	zone->uz_slab = zone_fetch_slab_multi;
1967 
1968 out:
1969 	zone_unlock_pair(zone, master);
1970 	if (klink != NULL)
1971 		free(klink, M_TEMP);
1972 
1973 	return (error);
1974 }
1975 
1976 
1977 /* See uma.h */
1978 void
1979 uma_zdestroy(uma_zone_t zone)
1980 {
1981 
1982 	zone_free_item(zones, zone, NULL, SKIP_NONE);
1983 }
1984 
1985 /* See uma.h */
1986 void *
1987 uma_zalloc_arg(uma_zone_t zone, void *udata, int flags)
1988 {
1989 	void *item;
1990 	uma_cache_t cache;
1991 	uma_bucket_t bucket;
1992 	int lockfail;
1993 	int cpu;
1994 
1995 	/* This is the fast path allocation */
1996 #ifdef UMA_DEBUG_ALLOC_1
1997 	printf("Allocating one item from %s(%p)\n", zone->uz_name, zone);
1998 #endif
1999 	CTR3(KTR_UMA, "uma_zalloc_arg thread %x zone %s flags %d", curthread,
2000 	    zone->uz_name, flags);
2001 
2002 	if (flags & M_WAITOK) {
2003 		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
2004 		    "uma_zalloc_arg: zone \"%s\"", zone->uz_name);
2005 	}
2006 #ifdef DEBUG_MEMGUARD
2007 	if (memguard_cmp_zone(zone)) {
2008 		item = memguard_alloc(zone->uz_size, flags);
2009 		if (item != NULL) {
2010 			/*
2011 			 * Avoid conflict with the use-after-free
2012 			 * protecting infrastructure from INVARIANTS.
2013 			 */
2014 			if (zone->uz_init != NULL &&
2015 			    zone->uz_init != mtrash_init &&
2016 			    zone->uz_init(item, zone->uz_size, flags) != 0)
2017 				return (NULL);
2018 			if (zone->uz_ctor != NULL &&
2019 			    zone->uz_ctor != mtrash_ctor &&
2020 			    zone->uz_ctor(item, zone->uz_size, udata,
2021 			    flags) != 0) {
2022 			    	zone->uz_fini(item, zone->uz_size);
2023 				return (NULL);
2024 			}
2025 			return (item);
2026 		}
2027 		/* This is unfortunate but should not be fatal. */
2028 	}
2029 #endif
2030 	/*
2031 	 * If possible, allocate from the per-CPU cache.  There are two
2032 	 * requirements for safe access to the per-CPU cache: (1) the thread
2033 	 * accessing the cache must not be preempted or yield during access,
2034 	 * and (2) the thread must not migrate CPUs without switching which
2035 	 * cache it accesses.  We rely on a critical section to prevent
2036 	 * preemption and migration.  We release the critical section in
2037 	 * order to acquire the zone mutex if we are unable to allocate from
2038 	 * the current cache; when we re-acquire the critical section, we
2039 	 * must detect and handle migration if it has occurred.
2040 	 */
2041 	critical_enter();
2042 	cpu = curcpu;
2043 	cache = &zone->uz_cpu[cpu];
2044 
2045 zalloc_start:
2046 	bucket = cache->uc_allocbucket;
2047 	if (bucket != NULL && bucket->ub_cnt > 0) {
2048 		bucket->ub_cnt--;
2049 		item = bucket->ub_bucket[bucket->ub_cnt];
2050 #ifdef INVARIANTS
2051 		bucket->ub_bucket[bucket->ub_cnt] = NULL;
2052 #endif
2053 		KASSERT(item != NULL, ("uma_zalloc: Bucket pointer mangled."));
2054 		cache->uc_allocs++;
2055 		critical_exit();
2056 		if (zone->uz_ctor != NULL &&
2057 		    zone->uz_ctor(item, zone->uz_size, udata, flags) != 0) {
2058 			atomic_add_long(&zone->uz_fails, 1);
2059 			zone_free_item(zone, item, udata, SKIP_DTOR);
2060 			return (NULL);
2061 		}
2062 #ifdef INVARIANTS
2063 		uma_dbg_alloc(zone, NULL, item);
2064 #endif
2065 		if (flags & M_ZERO)
2066 			bzero(item, zone->uz_size);
2067 		return (item);
2068 	}
2069 
2070 	/*
2071 	 * We have run out of items in our alloc bucket.
2072 	 * See if we can switch with our free bucket.
2073 	 */
2074 	bucket = cache->uc_freebucket;
2075 	if (bucket != NULL && bucket->ub_cnt > 0) {
2076 #ifdef UMA_DEBUG_ALLOC
2077 		printf("uma_zalloc: Swapping empty with alloc.\n");
2078 #endif
2079 		cache->uc_freebucket = cache->uc_allocbucket;
2080 		cache->uc_allocbucket = bucket;
2081 		goto zalloc_start;
2082 	}
2083 
2084 	/*
2085 	 * Discard any empty allocation bucket while we hold no locks.
2086 	 */
2087 	bucket = cache->uc_allocbucket;
2088 	cache->uc_allocbucket = NULL;
2089 	critical_exit();
2090 	if (bucket != NULL)
2091 		bucket_free(zone, bucket, udata);
2092 
2093 	/* Short-circuit for zones without buckets and low memory. */
2094 	if (zone->uz_count == 0 || bucketdisable)
2095 		goto zalloc_item;
2096 
2097 	/*
2098 	 * Attempt to retrieve the item from the per-CPU cache has failed, so
2099 	 * we must go back to the zone.  This requires the zone lock, so we
2100 	 * must drop the critical section, then re-acquire it when we go back
2101 	 * to the cache.  Since the critical section is released, we may be
2102 	 * preempted or migrate.  As such, make sure not to maintain any
2103 	 * thread-local state specific to the cache from prior to releasing
2104 	 * the critical section.
2105 	 */
2106 	lockfail = 0;
2107 	if (ZONE_TRYLOCK(zone) == 0) {
2108 		/* Record contention to size the buckets. */
2109 		ZONE_LOCK(zone);
2110 		lockfail = 1;
2111 	}
2112 	critical_enter();
2113 	cpu = curcpu;
2114 	cache = &zone->uz_cpu[cpu];
2115 
2116 	/*
2117 	 * Since we have locked the zone we may as well send back our stats.
2118 	 */
2119 	atomic_add_long(&zone->uz_allocs, cache->uc_allocs);
2120 	atomic_add_long(&zone->uz_frees, cache->uc_frees);
2121 	cache->uc_allocs = 0;
2122 	cache->uc_frees = 0;
2123 
2124 	/* See if we lost the race to fill the cache. */
2125 	if (cache->uc_allocbucket != NULL) {
2126 		ZONE_UNLOCK(zone);
2127 		goto zalloc_start;
2128 	}
2129 
2130 	/*
2131 	 * Check the zone's cache of buckets.
2132 	 */
2133 	if ((bucket = LIST_FIRST(&zone->uz_buckets)) != NULL) {
2134 		KASSERT(bucket->ub_cnt != 0,
2135 		    ("uma_zalloc_arg: Returning an empty bucket."));
2136 
2137 		LIST_REMOVE(bucket, ub_link);
2138 		cache->uc_allocbucket = bucket;
2139 		ZONE_UNLOCK(zone);
2140 		goto zalloc_start;
2141 	}
2142 	/* We are no longer associated with this CPU. */
2143 	critical_exit();
2144 
2145 	/*
2146 	 * We bump the uz count when the cache size is insufficient to
2147 	 * handle the working set.
2148 	 */
2149 	if (lockfail && zone->uz_count < BUCKET_MAX)
2150 		zone->uz_count++;
2151 	ZONE_UNLOCK(zone);
2152 
2153 	/*
2154 	 * Now lets just fill a bucket and put it on the free list.  If that
2155 	 * works we'll restart the allocation from the begining and it
2156 	 * will use the just filled bucket.
2157 	 */
2158 	bucket = zone_alloc_bucket(zone, udata, flags);
2159 	if (bucket != NULL) {
2160 		ZONE_LOCK(zone);
2161 		critical_enter();
2162 		cpu = curcpu;
2163 		cache = &zone->uz_cpu[cpu];
2164 		/*
2165 		 * See if we lost the race or were migrated.  Cache the
2166 		 * initialized bucket to make this less likely or claim
2167 		 * the memory directly.
2168 		 */
2169 		if (cache->uc_allocbucket == NULL)
2170 			cache->uc_allocbucket = bucket;
2171 		else
2172 			LIST_INSERT_HEAD(&zone->uz_buckets, bucket, ub_link);
2173 		ZONE_UNLOCK(zone);
2174 		goto zalloc_start;
2175 	}
2176 
2177 	/*
2178 	 * We may not be able to get a bucket so return an actual item.
2179 	 */
2180 #ifdef UMA_DEBUG
2181 	printf("uma_zalloc_arg: Bucketzone returned NULL\n");
2182 #endif
2183 
2184 zalloc_item:
2185 	item = zone_alloc_item(zone, udata, flags);
2186 
2187 	return (item);
2188 }
2189 
2190 static uma_slab_t
2191 keg_fetch_slab(uma_keg_t keg, uma_zone_t zone, int flags)
2192 {
2193 	uma_slab_t slab;
2194 	int reserve;
2195 
2196 	mtx_assert(&keg->uk_lock, MA_OWNED);
2197 	slab = NULL;
2198 	reserve = 0;
2199 	if ((flags & M_USE_RESERVE) == 0)
2200 		reserve = keg->uk_reserve;
2201 
2202 	for (;;) {
2203 		/*
2204 		 * Find a slab with some space.  Prefer slabs that are partially
2205 		 * used over those that are totally full.  This helps to reduce
2206 		 * fragmentation.
2207 		 */
2208 		if (keg->uk_free > reserve) {
2209 			if (!LIST_EMPTY(&keg->uk_part_slab)) {
2210 				slab = LIST_FIRST(&keg->uk_part_slab);
2211 			} else {
2212 				slab = LIST_FIRST(&keg->uk_free_slab);
2213 				LIST_REMOVE(slab, us_link);
2214 				LIST_INSERT_HEAD(&keg->uk_part_slab, slab,
2215 				    us_link);
2216 			}
2217 			MPASS(slab->us_keg == keg);
2218 			return (slab);
2219 		}
2220 
2221 		/*
2222 		 * M_NOVM means don't ask at all!
2223 		 */
2224 		if (flags & M_NOVM)
2225 			break;
2226 
2227 		if (keg->uk_maxpages && keg->uk_pages >= keg->uk_maxpages) {
2228 			keg->uk_flags |= UMA_ZFLAG_FULL;
2229 			/*
2230 			 * If this is not a multi-zone, set the FULL bit.
2231 			 * Otherwise slab_multi() takes care of it.
2232 			 */
2233 			if ((zone->uz_flags & UMA_ZFLAG_MULTI) == 0) {
2234 				zone->uz_flags |= UMA_ZFLAG_FULL;
2235 				zone_log_warning(zone);
2236 			}
2237 			if (flags & M_NOWAIT)
2238 				break;
2239 			zone->uz_sleeps++;
2240 			msleep(keg, &keg->uk_lock, PVM, "keglimit", 0);
2241 			continue;
2242 		}
2243 		slab = keg_alloc_slab(keg, zone, flags);
2244 		/*
2245 		 * If we got a slab here it's safe to mark it partially used
2246 		 * and return.  We assume that the caller is going to remove
2247 		 * at least one item.
2248 		 */
2249 		if (slab) {
2250 			MPASS(slab->us_keg == keg);
2251 			LIST_INSERT_HEAD(&keg->uk_part_slab, slab, us_link);
2252 			return (slab);
2253 		}
2254 		/*
2255 		 * We might not have been able to get a slab but another cpu
2256 		 * could have while we were unlocked.  Check again before we
2257 		 * fail.
2258 		 */
2259 		flags |= M_NOVM;
2260 	}
2261 	return (slab);
2262 }
2263 
2264 static uma_slab_t
2265 zone_fetch_slab(uma_zone_t zone, uma_keg_t keg, int flags)
2266 {
2267 	uma_slab_t slab;
2268 
2269 	if (keg == NULL) {
2270 		keg = zone_first_keg(zone);
2271 		KEG_LOCK(keg);
2272 	}
2273 
2274 	for (;;) {
2275 		slab = keg_fetch_slab(keg, zone, flags);
2276 		if (slab)
2277 			return (slab);
2278 		if (flags & (M_NOWAIT | M_NOVM))
2279 			break;
2280 	}
2281 	KEG_UNLOCK(keg);
2282 	return (NULL);
2283 }
2284 
2285 /*
2286  * uma_zone_fetch_slab_multi:  Fetches a slab from one available keg.  Returns
2287  * with the keg locked.  On NULL no lock is held.
2288  *
2289  * The last pointer is used to seed the search.  It is not required.
2290  */
2291 static uma_slab_t
2292 zone_fetch_slab_multi(uma_zone_t zone, uma_keg_t last, int rflags)
2293 {
2294 	uma_klink_t klink;
2295 	uma_slab_t slab;
2296 	uma_keg_t keg;
2297 	int flags;
2298 	int empty;
2299 	int full;
2300 
2301 	/*
2302 	 * Don't wait on the first pass.  This will skip limit tests
2303 	 * as well.  We don't want to block if we can find a provider
2304 	 * without blocking.
2305 	 */
2306 	flags = (rflags & ~M_WAITOK) | M_NOWAIT;
2307 	/*
2308 	 * Use the last slab allocated as a hint for where to start
2309 	 * the search.
2310 	 */
2311 	if (last != NULL) {
2312 		slab = keg_fetch_slab(last, zone, flags);
2313 		if (slab)
2314 			return (slab);
2315 		KEG_UNLOCK(last);
2316 	}
2317 	/*
2318 	 * Loop until we have a slab incase of transient failures
2319 	 * while M_WAITOK is specified.  I'm not sure this is 100%
2320 	 * required but we've done it for so long now.
2321 	 */
2322 	for (;;) {
2323 		empty = 0;
2324 		full = 0;
2325 		/*
2326 		 * Search the available kegs for slabs.  Be careful to hold the
2327 		 * correct lock while calling into the keg layer.
2328 		 */
2329 		LIST_FOREACH(klink, &zone->uz_kegs, kl_link) {
2330 			keg = klink->kl_keg;
2331 			KEG_LOCK(keg);
2332 			if ((keg->uk_flags & UMA_ZFLAG_FULL) == 0) {
2333 				slab = keg_fetch_slab(keg, zone, flags);
2334 				if (slab)
2335 					return (slab);
2336 			}
2337 			if (keg->uk_flags & UMA_ZFLAG_FULL)
2338 				full++;
2339 			else
2340 				empty++;
2341 			KEG_UNLOCK(keg);
2342 		}
2343 		if (rflags & (M_NOWAIT | M_NOVM))
2344 			break;
2345 		flags = rflags;
2346 		/*
2347 		 * All kegs are full.  XXX We can't atomically check all kegs
2348 		 * and sleep so just sleep for a short period and retry.
2349 		 */
2350 		if (full && !empty) {
2351 			ZONE_LOCK(zone);
2352 			zone->uz_flags |= UMA_ZFLAG_FULL;
2353 			zone->uz_sleeps++;
2354 			zone_log_warning(zone);
2355 			msleep(zone, zone->uz_lockptr, PVM,
2356 			    "zonelimit", hz/100);
2357 			zone->uz_flags &= ~UMA_ZFLAG_FULL;
2358 			ZONE_UNLOCK(zone);
2359 			continue;
2360 		}
2361 	}
2362 	return (NULL);
2363 }
2364 
2365 static void *
2366 slab_alloc_item(uma_keg_t keg, uma_slab_t slab)
2367 {
2368 	void *item;
2369 	uint8_t freei;
2370 
2371 	MPASS(keg == slab->us_keg);
2372 	mtx_assert(&keg->uk_lock, MA_OWNED);
2373 
2374 	freei = BIT_FFS(SLAB_SETSIZE, &slab->us_free) - 1;
2375 	BIT_CLR(SLAB_SETSIZE, freei, &slab->us_free);
2376 	item = slab->us_data + (keg->uk_rsize * freei);
2377 	slab->us_freecount--;
2378 	keg->uk_free--;
2379 
2380 	/* Move this slab to the full list */
2381 	if (slab->us_freecount == 0) {
2382 		LIST_REMOVE(slab, us_link);
2383 		LIST_INSERT_HEAD(&keg->uk_full_slab, slab, us_link);
2384 	}
2385 
2386 	return (item);
2387 }
2388 
2389 static int
2390 zone_import(uma_zone_t zone, void **bucket, int max, int flags)
2391 {
2392 	uma_slab_t slab;
2393 	uma_keg_t keg;
2394 	int i;
2395 
2396 	slab = NULL;
2397 	keg = NULL;
2398 	/* Try to keep the buckets totally full */
2399 	for (i = 0; i < max; ) {
2400 		if ((slab = zone->uz_slab(zone, keg, flags)) == NULL)
2401 			break;
2402 		keg = slab->us_keg;
2403 		while (slab->us_freecount && i < max) {
2404 			bucket[i++] = slab_alloc_item(keg, slab);
2405 			if (keg->uk_free <= keg->uk_reserve)
2406 				break;
2407 		}
2408 		/* Don't grab more than one slab at a time. */
2409 		flags &= ~M_WAITOK;
2410 		flags |= M_NOWAIT;
2411 	}
2412 	if (slab != NULL)
2413 		KEG_UNLOCK(keg);
2414 
2415 	return i;
2416 }
2417 
2418 static uma_bucket_t
2419 zone_alloc_bucket(uma_zone_t zone, void *udata, int flags)
2420 {
2421 	uma_bucket_t bucket;
2422 	int max;
2423 
2424 	/* Don't wait for buckets, preserve caller's NOVM setting. */
2425 	bucket = bucket_alloc(zone, udata, M_NOWAIT | (flags & M_NOVM));
2426 	if (bucket == NULL)
2427 		goto out;
2428 
2429 	max = MIN(bucket->ub_entries, zone->uz_count);
2430 	bucket->ub_cnt = zone->uz_import(zone->uz_arg, bucket->ub_bucket,
2431 	    max, flags);
2432 
2433 	/*
2434 	 * Initialize the memory if necessary.
2435 	 */
2436 	if (bucket->ub_cnt != 0 && zone->uz_init != NULL) {
2437 		int i;
2438 
2439 		for (i = 0; i < bucket->ub_cnt; i++)
2440 			if (zone->uz_init(bucket->ub_bucket[i], zone->uz_size,
2441 			    flags) != 0)
2442 				break;
2443 		/*
2444 		 * If we couldn't initialize the whole bucket, put the
2445 		 * rest back onto the freelist.
2446 		 */
2447 		if (i != bucket->ub_cnt) {
2448 			zone->uz_release(zone->uz_arg, &bucket->ub_bucket[i],
2449 			    bucket->ub_cnt - i);
2450 #ifdef INVARIANTS
2451 			bzero(&bucket->ub_bucket[i],
2452 			    sizeof(void *) * (bucket->ub_cnt - i));
2453 #endif
2454 			bucket->ub_cnt = i;
2455 		}
2456 	}
2457 
2458 out:
2459 	if (bucket == NULL || bucket->ub_cnt == 0) {
2460 		if (bucket != NULL)
2461 			bucket_free(zone, bucket, udata);
2462 		atomic_add_long(&zone->uz_fails, 1);
2463 		return (NULL);
2464 	}
2465 
2466 	return (bucket);
2467 }
2468 
2469 /*
2470  * Allocates a single item from a zone.
2471  *
2472  * Arguments
2473  *	zone   The zone to alloc for.
2474  *	udata  The data to be passed to the constructor.
2475  *	flags  M_WAITOK, M_NOWAIT, M_ZERO.
2476  *
2477  * Returns
2478  *	NULL if there is no memory and M_NOWAIT is set
2479  *	An item if successful
2480  */
2481 
2482 static void *
2483 zone_alloc_item(uma_zone_t zone, void *udata, int flags)
2484 {
2485 	void *item;
2486 
2487 	item = NULL;
2488 
2489 #ifdef UMA_DEBUG_ALLOC
2490 	printf("INTERNAL: Allocating one item from %s(%p)\n", zone->uz_name, zone);
2491 #endif
2492 	if (zone->uz_import(zone->uz_arg, &item, 1, flags) != 1)
2493 		goto fail;
2494 	atomic_add_long(&zone->uz_allocs, 1);
2495 
2496 	/*
2497 	 * We have to call both the zone's init (not the keg's init)
2498 	 * and the zone's ctor.  This is because the item is going from
2499 	 * a keg slab directly to the user, and the user is expecting it
2500 	 * to be both zone-init'd as well as zone-ctor'd.
2501 	 */
2502 	if (zone->uz_init != NULL) {
2503 		if (zone->uz_init(item, zone->uz_size, flags) != 0) {
2504 			zone_free_item(zone, item, udata, SKIP_FINI);
2505 			goto fail;
2506 		}
2507 	}
2508 	if (zone->uz_ctor != NULL) {
2509 		if (zone->uz_ctor(item, zone->uz_size, udata, flags) != 0) {
2510 			zone_free_item(zone, item, udata, SKIP_DTOR);
2511 			goto fail;
2512 		}
2513 	}
2514 #ifdef INVARIANTS
2515 	uma_dbg_alloc(zone, NULL, item);
2516 #endif
2517 	if (flags & M_ZERO)
2518 		bzero(item, zone->uz_size);
2519 
2520 	return (item);
2521 
2522 fail:
2523 	atomic_add_long(&zone->uz_fails, 1);
2524 	return (NULL);
2525 }
2526 
2527 /* See uma.h */
2528 void
2529 uma_zfree_arg(uma_zone_t zone, void *item, void *udata)
2530 {
2531 	uma_cache_t cache;
2532 	uma_bucket_t bucket;
2533 	int cpu;
2534 
2535 #ifdef UMA_DEBUG_ALLOC_1
2536 	printf("Freeing item %p to %s(%p)\n", item, zone->uz_name, zone);
2537 #endif
2538 	CTR2(KTR_UMA, "uma_zfree_arg thread %x zone %s", curthread,
2539 	    zone->uz_name);
2540 
2541         /* uma_zfree(..., NULL) does nothing, to match free(9). */
2542         if (item == NULL)
2543                 return;
2544 #ifdef DEBUG_MEMGUARD
2545 	if (is_memguard_addr(item)) {
2546 		if (zone->uz_dtor != NULL && zone->uz_dtor != mtrash_dtor)
2547 			zone->uz_dtor(item, zone->uz_size, udata);
2548 		if (zone->uz_fini != NULL && zone->uz_fini != mtrash_fini)
2549 			zone->uz_fini(item, zone->uz_size);
2550 		memguard_free(item);
2551 		return;
2552 	}
2553 #endif
2554 #ifdef INVARIANTS
2555 	if (zone->uz_flags & UMA_ZONE_MALLOC)
2556 		uma_dbg_free(zone, udata, item);
2557 	else
2558 		uma_dbg_free(zone, NULL, item);
2559 #endif
2560 	if (zone->uz_dtor != NULL)
2561 		zone->uz_dtor(item, zone->uz_size, udata);
2562 
2563 	/*
2564 	 * The race here is acceptable.  If we miss it we'll just have to wait
2565 	 * a little longer for the limits to be reset.
2566 	 */
2567 	if (zone->uz_flags & UMA_ZFLAG_FULL)
2568 		goto zfree_item;
2569 
2570 	/*
2571 	 * If possible, free to the per-CPU cache.  There are two
2572 	 * requirements for safe access to the per-CPU cache: (1) the thread
2573 	 * accessing the cache must not be preempted or yield during access,
2574 	 * and (2) the thread must not migrate CPUs without switching which
2575 	 * cache it accesses.  We rely on a critical section to prevent
2576 	 * preemption and migration.  We release the critical section in
2577 	 * order to acquire the zone mutex if we are unable to free to the
2578 	 * current cache; when we re-acquire the critical section, we must
2579 	 * detect and handle migration if it has occurred.
2580 	 */
2581 zfree_restart:
2582 	critical_enter();
2583 	cpu = curcpu;
2584 	cache = &zone->uz_cpu[cpu];
2585 
2586 zfree_start:
2587 	/*
2588 	 * Try to free into the allocbucket first to give LIFO ordering
2589 	 * for cache-hot datastructures.  Spill over into the freebucket
2590 	 * if necessary.  Alloc will swap them if one runs dry.
2591 	 */
2592 	bucket = cache->uc_allocbucket;
2593 	if (bucket == NULL || bucket->ub_cnt >= bucket->ub_entries)
2594 		bucket = cache->uc_freebucket;
2595 	if (bucket != NULL && bucket->ub_cnt < bucket->ub_entries) {
2596 		KASSERT(bucket->ub_bucket[bucket->ub_cnt] == NULL,
2597 		    ("uma_zfree: Freeing to non free bucket index."));
2598 		bucket->ub_bucket[bucket->ub_cnt] = item;
2599 		bucket->ub_cnt++;
2600 		cache->uc_frees++;
2601 		critical_exit();
2602 		return;
2603 	}
2604 
2605 	/*
2606 	 * We must go back the zone, which requires acquiring the zone lock,
2607 	 * which in turn means we must release and re-acquire the critical
2608 	 * section.  Since the critical section is released, we may be
2609 	 * preempted or migrate.  As such, make sure not to maintain any
2610 	 * thread-local state specific to the cache from prior to releasing
2611 	 * the critical section.
2612 	 */
2613 	critical_exit();
2614 	if (zone->uz_count == 0 || bucketdisable)
2615 		goto zfree_item;
2616 
2617 	ZONE_LOCK(zone);
2618 	critical_enter();
2619 	cpu = curcpu;
2620 	cache = &zone->uz_cpu[cpu];
2621 
2622 	/*
2623 	 * Since we have locked the zone we may as well send back our stats.
2624 	 */
2625 	atomic_add_long(&zone->uz_allocs, cache->uc_allocs);
2626 	atomic_add_long(&zone->uz_frees, cache->uc_frees);
2627 	cache->uc_allocs = 0;
2628 	cache->uc_frees = 0;
2629 
2630 	bucket = cache->uc_freebucket;
2631 	if (bucket != NULL && bucket->ub_cnt < bucket->ub_entries) {
2632 		ZONE_UNLOCK(zone);
2633 		goto zfree_start;
2634 	}
2635 	cache->uc_freebucket = NULL;
2636 
2637 	/* Can we throw this on the zone full list? */
2638 	if (bucket != NULL) {
2639 #ifdef UMA_DEBUG_ALLOC
2640 		printf("uma_zfree: Putting old bucket on the free list.\n");
2641 #endif
2642 		/* ub_cnt is pointing to the last free item */
2643 		KASSERT(bucket->ub_cnt != 0,
2644 		    ("uma_zfree: Attempting to insert an empty bucket onto the full list.\n"));
2645 		LIST_INSERT_HEAD(&zone->uz_buckets, bucket, ub_link);
2646 	}
2647 
2648 	/* We are no longer associated with this CPU. */
2649 	critical_exit();
2650 
2651 	/* And the zone.. */
2652 	ZONE_UNLOCK(zone);
2653 
2654 #ifdef UMA_DEBUG_ALLOC
2655 	printf("uma_zfree: Allocating new free bucket.\n");
2656 #endif
2657 	bucket = bucket_alloc(zone, udata, M_NOWAIT);
2658 	if (bucket) {
2659 		critical_enter();
2660 		cpu = curcpu;
2661 		cache = &zone->uz_cpu[cpu];
2662 		if (cache->uc_freebucket == NULL) {
2663 			cache->uc_freebucket = bucket;
2664 			goto zfree_start;
2665 		}
2666 		/*
2667 		 * We lost the race, start over.  We have to drop our
2668 		 * critical section to free the bucket.
2669 		 */
2670 		critical_exit();
2671 		bucket_free(zone, bucket, udata);
2672 		goto zfree_restart;
2673 	}
2674 
2675 	/*
2676 	 * If nothing else caught this, we'll just do an internal free.
2677 	 */
2678 zfree_item:
2679 	zone_free_item(zone, item, udata, SKIP_DTOR);
2680 
2681 	return;
2682 }
2683 
2684 static void
2685 slab_free_item(uma_keg_t keg, uma_slab_t slab, void *item)
2686 {
2687 	uint8_t freei;
2688 
2689 	mtx_assert(&keg->uk_lock, MA_OWNED);
2690 	MPASS(keg == slab->us_keg);
2691 
2692 	/* Do we need to remove from any lists? */
2693 	if (slab->us_freecount+1 == keg->uk_ipers) {
2694 		LIST_REMOVE(slab, us_link);
2695 		LIST_INSERT_HEAD(&keg->uk_free_slab, slab, us_link);
2696 	} else if (slab->us_freecount == 0) {
2697 		LIST_REMOVE(slab, us_link);
2698 		LIST_INSERT_HEAD(&keg->uk_part_slab, slab, us_link);
2699 	}
2700 
2701 	/* Slab management. */
2702 	freei = ((uintptr_t)item - (uintptr_t)slab->us_data) / keg->uk_rsize;
2703 	BIT_SET(SLAB_SETSIZE, freei, &slab->us_free);
2704 	slab->us_freecount++;
2705 
2706 	/* Keg statistics. */
2707 	keg->uk_free++;
2708 }
2709 
2710 static void
2711 zone_release(uma_zone_t zone, void **bucket, int cnt)
2712 {
2713 	void *item;
2714 	uma_slab_t slab;
2715 	uma_keg_t keg;
2716 	uint8_t *mem;
2717 	int clearfull;
2718 	int i;
2719 
2720 	clearfull = 0;
2721 	keg = zone_first_keg(zone);
2722 	KEG_LOCK(keg);
2723 	for (i = 0; i < cnt; i++) {
2724 		item = bucket[i];
2725 		if (!(zone->uz_flags & UMA_ZONE_VTOSLAB)) {
2726 			mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
2727 			if (zone->uz_flags & UMA_ZONE_HASH) {
2728 				slab = hash_sfind(&keg->uk_hash, mem);
2729 			} else {
2730 				mem += keg->uk_pgoff;
2731 				slab = (uma_slab_t)mem;
2732 			}
2733 		} else {
2734 			slab = vtoslab((vm_offset_t)item);
2735 			if (slab->us_keg != keg) {
2736 				KEG_UNLOCK(keg);
2737 				keg = slab->us_keg;
2738 				KEG_LOCK(keg);
2739 			}
2740 		}
2741 		slab_free_item(keg, slab, item);
2742 		if (keg->uk_flags & UMA_ZFLAG_FULL) {
2743 			if (keg->uk_pages < keg->uk_maxpages) {
2744 				keg->uk_flags &= ~UMA_ZFLAG_FULL;
2745 				clearfull = 1;
2746 			}
2747 
2748 			/*
2749 			 * We can handle one more allocation. Since we're
2750 			 * clearing ZFLAG_FULL, wake up all procs blocked
2751 			 * on pages. This should be uncommon, so keeping this
2752 			 * simple for now (rather than adding count of blocked
2753 			 * threads etc).
2754 			 */
2755 			wakeup(keg);
2756 		}
2757 	}
2758 	KEG_UNLOCK(keg);
2759 	if (clearfull) {
2760 		ZONE_LOCK(zone);
2761 		zone->uz_flags &= ~UMA_ZFLAG_FULL;
2762 		wakeup(zone);
2763 		ZONE_UNLOCK(zone);
2764 	}
2765 
2766 }
2767 
2768 /*
2769  * Frees a single item to any zone.
2770  *
2771  * Arguments:
2772  *	zone   The zone to free to
2773  *	item   The item we're freeing
2774  *	udata  User supplied data for the dtor
2775  *	skip   Skip dtors and finis
2776  */
2777 static void
2778 zone_free_item(uma_zone_t zone, void *item, void *udata, enum zfreeskip skip)
2779 {
2780 
2781 #ifdef INVARIANTS
2782 	if (skip == SKIP_NONE) {
2783 		if (zone->uz_flags & UMA_ZONE_MALLOC)
2784 			uma_dbg_free(zone, udata, item);
2785 		else
2786 			uma_dbg_free(zone, NULL, item);
2787 	}
2788 #endif
2789 	if (skip < SKIP_DTOR && zone->uz_dtor)
2790 		zone->uz_dtor(item, zone->uz_size, udata);
2791 
2792 	if (skip < SKIP_FINI && zone->uz_fini)
2793 		zone->uz_fini(item, zone->uz_size);
2794 
2795 	atomic_add_long(&zone->uz_frees, 1);
2796 	zone->uz_release(zone->uz_arg, &item, 1);
2797 }
2798 
2799 /* See uma.h */
2800 int
2801 uma_zone_set_max(uma_zone_t zone, int nitems)
2802 {
2803 	uma_keg_t keg;
2804 
2805 	keg = zone_first_keg(zone);
2806 	if (keg == NULL)
2807 		return (0);
2808 	KEG_LOCK(keg);
2809 	keg->uk_maxpages = (nitems / keg->uk_ipers) * keg->uk_ppera;
2810 	if (keg->uk_maxpages * keg->uk_ipers < nitems)
2811 		keg->uk_maxpages += keg->uk_ppera;
2812 	nitems = keg->uk_maxpages * keg->uk_ipers;
2813 	KEG_UNLOCK(keg);
2814 
2815 	return (nitems);
2816 }
2817 
2818 /* See uma.h */
2819 int
2820 uma_zone_get_max(uma_zone_t zone)
2821 {
2822 	int nitems;
2823 	uma_keg_t keg;
2824 
2825 	keg = zone_first_keg(zone);
2826 	if (keg == NULL)
2827 		return (0);
2828 	KEG_LOCK(keg);
2829 	nitems = keg->uk_maxpages * keg->uk_ipers;
2830 	KEG_UNLOCK(keg);
2831 
2832 	return (nitems);
2833 }
2834 
2835 /* See uma.h */
2836 void
2837 uma_zone_set_warning(uma_zone_t zone, const char *warning)
2838 {
2839 
2840 	ZONE_LOCK(zone);
2841 	zone->uz_warning = warning;
2842 	ZONE_UNLOCK(zone);
2843 }
2844 
2845 /* See uma.h */
2846 int
2847 uma_zone_get_cur(uma_zone_t zone)
2848 {
2849 	int64_t nitems;
2850 	u_int i;
2851 
2852 	ZONE_LOCK(zone);
2853 	nitems = zone->uz_allocs - zone->uz_frees;
2854 	CPU_FOREACH(i) {
2855 		/*
2856 		 * See the comment in sysctl_vm_zone_stats() regarding the
2857 		 * safety of accessing the per-cpu caches. With the zone lock
2858 		 * held, it is safe, but can potentially result in stale data.
2859 		 */
2860 		nitems += zone->uz_cpu[i].uc_allocs -
2861 		    zone->uz_cpu[i].uc_frees;
2862 	}
2863 	ZONE_UNLOCK(zone);
2864 
2865 	return (nitems < 0 ? 0 : nitems);
2866 }
2867 
2868 /* See uma.h */
2869 void
2870 uma_zone_set_init(uma_zone_t zone, uma_init uminit)
2871 {
2872 	uma_keg_t keg;
2873 
2874 	keg = zone_first_keg(zone);
2875 	KASSERT(keg != NULL, ("uma_zone_set_init: Invalid zone type"));
2876 	KEG_LOCK(keg);
2877 	KASSERT(keg->uk_pages == 0,
2878 	    ("uma_zone_set_init on non-empty keg"));
2879 	keg->uk_init = uminit;
2880 	KEG_UNLOCK(keg);
2881 }
2882 
2883 /* See uma.h */
2884 void
2885 uma_zone_set_fini(uma_zone_t zone, uma_fini fini)
2886 {
2887 	uma_keg_t keg;
2888 
2889 	keg = zone_first_keg(zone);
2890 	KASSERT(keg != NULL, ("uma_zone_set_init: Invalid zone type"));
2891 	KEG_LOCK(keg);
2892 	KASSERT(keg->uk_pages == 0,
2893 	    ("uma_zone_set_fini on non-empty keg"));
2894 	keg->uk_fini = fini;
2895 	KEG_UNLOCK(keg);
2896 }
2897 
2898 /* See uma.h */
2899 void
2900 uma_zone_set_zinit(uma_zone_t zone, uma_init zinit)
2901 {
2902 
2903 	ZONE_LOCK(zone);
2904 	KASSERT(zone_first_keg(zone)->uk_pages == 0,
2905 	    ("uma_zone_set_zinit on non-empty keg"));
2906 	zone->uz_init = zinit;
2907 	ZONE_UNLOCK(zone);
2908 }
2909 
2910 /* See uma.h */
2911 void
2912 uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini)
2913 {
2914 
2915 	ZONE_LOCK(zone);
2916 	KASSERT(zone_first_keg(zone)->uk_pages == 0,
2917 	    ("uma_zone_set_zfini on non-empty keg"));
2918 	zone->uz_fini = zfini;
2919 	ZONE_UNLOCK(zone);
2920 }
2921 
2922 /* See uma.h */
2923 /* XXX uk_freef is not actually used with the zone locked */
2924 void
2925 uma_zone_set_freef(uma_zone_t zone, uma_free freef)
2926 {
2927 	uma_keg_t keg;
2928 
2929 	keg = zone_first_keg(zone);
2930 	KASSERT(keg != NULL, ("uma_zone_set_init: Invalid zone type"));
2931 	KEG_LOCK(keg);
2932 	keg->uk_freef = freef;
2933 	KEG_UNLOCK(keg);
2934 }
2935 
2936 /* See uma.h */
2937 /* XXX uk_allocf is not actually used with the zone locked */
2938 void
2939 uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf)
2940 {
2941 	uma_keg_t keg;
2942 
2943 	keg = zone_first_keg(zone);
2944 	KEG_LOCK(keg);
2945 	keg->uk_allocf = allocf;
2946 	KEG_UNLOCK(keg);
2947 }
2948 
2949 /* See uma.h */
2950 void
2951 uma_zone_reserve(uma_zone_t zone, int items)
2952 {
2953 	uma_keg_t keg;
2954 
2955 	keg = zone_first_keg(zone);
2956 	if (keg == NULL)
2957 		return;
2958 	KEG_LOCK(keg);
2959 	keg->uk_reserve = items;
2960 	KEG_UNLOCK(keg);
2961 
2962 	return;
2963 }
2964 
2965 /* See uma.h */
2966 int
2967 uma_zone_reserve_kva(uma_zone_t zone, int count)
2968 {
2969 	uma_keg_t keg;
2970 	vm_offset_t kva;
2971 	int pages;
2972 
2973 	keg = zone_first_keg(zone);
2974 	if (keg == NULL)
2975 		return (0);
2976 	pages = count / keg->uk_ipers;
2977 
2978 	if (pages * keg->uk_ipers < count)
2979 		pages++;
2980 
2981 #ifdef UMA_MD_SMALL_ALLOC
2982 	if (keg->uk_ppera > 1) {
2983 #else
2984 	if (1) {
2985 #endif
2986 		kva = kmem_alloc_nofault(kernel_map, pages * UMA_SLAB_SIZE);
2987 		if (kva == 0)
2988 			return (0);
2989 	} else
2990 		kva = 0;
2991 	KEG_LOCK(keg);
2992 	keg->uk_kva = kva;
2993 	keg->uk_offset = 0;
2994 	keg->uk_maxpages = pages;
2995 #ifdef UMA_MD_SMALL_ALLOC
2996 	keg->uk_allocf = (keg->uk_ppera > 1) ? noobj_alloc : uma_small_alloc;
2997 #else
2998 	keg->uk_allocf = noobj_alloc;
2999 #endif
3000 	keg->uk_flags |= UMA_ZONE_NOFREE;
3001 	KEG_UNLOCK(keg);
3002 
3003 	return (1);
3004 }
3005 
3006 /* See uma.h */
3007 void
3008 uma_prealloc(uma_zone_t zone, int items)
3009 {
3010 	int slabs;
3011 	uma_slab_t slab;
3012 	uma_keg_t keg;
3013 
3014 	keg = zone_first_keg(zone);
3015 	if (keg == NULL)
3016 		return;
3017 	KEG_LOCK(keg);
3018 	slabs = items / keg->uk_ipers;
3019 	if (slabs * keg->uk_ipers < items)
3020 		slabs++;
3021 	while (slabs > 0) {
3022 		slab = keg_alloc_slab(keg, zone, M_WAITOK);
3023 		if (slab == NULL)
3024 			break;
3025 		MPASS(slab->us_keg == keg);
3026 		LIST_INSERT_HEAD(&keg->uk_free_slab, slab, us_link);
3027 		slabs--;
3028 	}
3029 	KEG_UNLOCK(keg);
3030 }
3031 
3032 /* See uma.h */
3033 uint32_t *
3034 uma_find_refcnt(uma_zone_t zone, void *item)
3035 {
3036 	uma_slabrefcnt_t slabref;
3037 	uma_slab_t slab;
3038 	uma_keg_t keg;
3039 	uint32_t *refcnt;
3040 	int idx;
3041 
3042 	slab = vtoslab((vm_offset_t)item & (~UMA_SLAB_MASK));
3043 	slabref = (uma_slabrefcnt_t)slab;
3044 	keg = slab->us_keg;
3045 	KASSERT(keg->uk_flags & UMA_ZONE_REFCNT,
3046 	    ("uma_find_refcnt(): zone possibly not UMA_ZONE_REFCNT"));
3047 	idx = ((uintptr_t)item - (uintptr_t)slab->us_data) / keg->uk_rsize;
3048 	refcnt = &slabref->us_refcnt[idx];
3049 	return refcnt;
3050 }
3051 
3052 /* See uma.h */
3053 void
3054 uma_reclaim(void)
3055 {
3056 #ifdef UMA_DEBUG
3057 	printf("UMA: vm asked us to release pages!\n");
3058 #endif
3059 	bucket_enable();
3060 	zone_foreach(zone_drain);
3061 	/*
3062 	 * Some slabs may have been freed but this zone will be visited early
3063 	 * we visit again so that we can free pages that are empty once other
3064 	 * zones are drained.  We have to do the same for buckets.
3065 	 */
3066 	zone_drain(slabzone);
3067 	zone_drain(slabrefzone);
3068 	bucket_zone_drain();
3069 }
3070 
3071 /* See uma.h */
3072 int
3073 uma_zone_exhausted(uma_zone_t zone)
3074 {
3075 	int full;
3076 
3077 	ZONE_LOCK(zone);
3078 	full = (zone->uz_flags & UMA_ZFLAG_FULL);
3079 	ZONE_UNLOCK(zone);
3080 	return (full);
3081 }
3082 
3083 int
3084 uma_zone_exhausted_nolock(uma_zone_t zone)
3085 {
3086 	return (zone->uz_flags & UMA_ZFLAG_FULL);
3087 }
3088 
3089 void *
3090 uma_large_malloc(int size, int wait)
3091 {
3092 	void *mem;
3093 	uma_slab_t slab;
3094 	uint8_t flags;
3095 
3096 	slab = zone_alloc_item(slabzone, NULL, wait);
3097 	if (slab == NULL)
3098 		return (NULL);
3099 	mem = page_alloc(NULL, size, &flags, wait);
3100 	if (mem) {
3101 		vsetslab((vm_offset_t)mem, slab);
3102 		slab->us_data = mem;
3103 		slab->us_flags = flags | UMA_SLAB_MALLOC;
3104 		slab->us_size = size;
3105 	} else {
3106 		zone_free_item(slabzone, slab, NULL, SKIP_NONE);
3107 	}
3108 
3109 	return (mem);
3110 }
3111 
3112 void
3113 uma_large_free(uma_slab_t slab)
3114 {
3115 	vsetobj((vm_offset_t)slab->us_data, kmem_object);
3116 	page_free(slab->us_data, slab->us_size, slab->us_flags);
3117 	zone_free_item(slabzone, slab, NULL, SKIP_NONE);
3118 }
3119 
3120 void
3121 uma_print_stats(void)
3122 {
3123 	zone_foreach(uma_print_zone);
3124 }
3125 
3126 static void
3127 slab_print(uma_slab_t slab)
3128 {
3129 	printf("slab: keg %p, data %p, freecount %d\n",
3130 		slab->us_keg, slab->us_data, slab->us_freecount);
3131 }
3132 
3133 static void
3134 cache_print(uma_cache_t cache)
3135 {
3136 	printf("alloc: %p(%d), free: %p(%d)\n",
3137 		cache->uc_allocbucket,
3138 		cache->uc_allocbucket?cache->uc_allocbucket->ub_cnt:0,
3139 		cache->uc_freebucket,
3140 		cache->uc_freebucket?cache->uc_freebucket->ub_cnt:0);
3141 }
3142 
3143 static void
3144 uma_print_keg(uma_keg_t keg)
3145 {
3146 	uma_slab_t slab;
3147 
3148 	printf("keg: %s(%p) size %d(%d) flags %#x ipers %d ppera %d "
3149 	    "out %d free %d limit %d\n",
3150 	    keg->uk_name, keg, keg->uk_size, keg->uk_rsize, keg->uk_flags,
3151 	    keg->uk_ipers, keg->uk_ppera,
3152 	    (keg->uk_ipers * keg->uk_pages) - keg->uk_free, keg->uk_free,
3153 	    (keg->uk_maxpages / keg->uk_ppera) * keg->uk_ipers);
3154 	printf("Part slabs:\n");
3155 	LIST_FOREACH(slab, &keg->uk_part_slab, us_link)
3156 		slab_print(slab);
3157 	printf("Free slabs:\n");
3158 	LIST_FOREACH(slab, &keg->uk_free_slab, us_link)
3159 		slab_print(slab);
3160 	printf("Full slabs:\n");
3161 	LIST_FOREACH(slab, &keg->uk_full_slab, us_link)
3162 		slab_print(slab);
3163 }
3164 
3165 void
3166 uma_print_zone(uma_zone_t zone)
3167 {
3168 	uma_cache_t cache;
3169 	uma_klink_t kl;
3170 	int i;
3171 
3172 	printf("zone: %s(%p) size %d flags %#x\n",
3173 	    zone->uz_name, zone, zone->uz_size, zone->uz_flags);
3174 	LIST_FOREACH(kl, &zone->uz_kegs, kl_link)
3175 		uma_print_keg(kl->kl_keg);
3176 	CPU_FOREACH(i) {
3177 		cache = &zone->uz_cpu[i];
3178 		printf("CPU %d Cache:\n", i);
3179 		cache_print(cache);
3180 	}
3181 }
3182 
3183 #ifdef DDB
3184 /*
3185  * Generate statistics across both the zone and its per-cpu cache's.  Return
3186  * desired statistics if the pointer is non-NULL for that statistic.
3187  *
3188  * Note: does not update the zone statistics, as it can't safely clear the
3189  * per-CPU cache statistic.
3190  *
3191  * XXXRW: Following the uc_allocbucket and uc_freebucket pointers here isn't
3192  * safe from off-CPU; we should modify the caches to track this information
3193  * directly so that we don't have to.
3194  */
3195 static void
3196 uma_zone_sumstat(uma_zone_t z, int *cachefreep, uint64_t *allocsp,
3197     uint64_t *freesp, uint64_t *sleepsp)
3198 {
3199 	uma_cache_t cache;
3200 	uint64_t allocs, frees, sleeps;
3201 	int cachefree, cpu;
3202 
3203 	allocs = frees = sleeps = 0;
3204 	cachefree = 0;
3205 	CPU_FOREACH(cpu) {
3206 		cache = &z->uz_cpu[cpu];
3207 		if (cache->uc_allocbucket != NULL)
3208 			cachefree += cache->uc_allocbucket->ub_cnt;
3209 		if (cache->uc_freebucket != NULL)
3210 			cachefree += cache->uc_freebucket->ub_cnt;
3211 		allocs += cache->uc_allocs;
3212 		frees += cache->uc_frees;
3213 	}
3214 	allocs += z->uz_allocs;
3215 	frees += z->uz_frees;
3216 	sleeps += z->uz_sleeps;
3217 	if (cachefreep != NULL)
3218 		*cachefreep = cachefree;
3219 	if (allocsp != NULL)
3220 		*allocsp = allocs;
3221 	if (freesp != NULL)
3222 		*freesp = frees;
3223 	if (sleepsp != NULL)
3224 		*sleepsp = sleeps;
3225 }
3226 #endif /* DDB */
3227 
3228 static int
3229 sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS)
3230 {
3231 	uma_keg_t kz;
3232 	uma_zone_t z;
3233 	int count;
3234 
3235 	count = 0;
3236 	mtx_lock(&uma_mtx);
3237 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3238 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
3239 			count++;
3240 	}
3241 	mtx_unlock(&uma_mtx);
3242 	return (sysctl_handle_int(oidp, &count, 0, req));
3243 }
3244 
3245 static int
3246 sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS)
3247 {
3248 	struct uma_stream_header ush;
3249 	struct uma_type_header uth;
3250 	struct uma_percpu_stat ups;
3251 	uma_bucket_t bucket;
3252 	struct sbuf sbuf;
3253 	uma_cache_t cache;
3254 	uma_klink_t kl;
3255 	uma_keg_t kz;
3256 	uma_zone_t z;
3257 	uma_keg_t k;
3258 	int count, error, i;
3259 
3260 	error = sysctl_wire_old_buffer(req, 0);
3261 	if (error != 0)
3262 		return (error);
3263 	sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
3264 
3265 	count = 0;
3266 	mtx_lock(&uma_mtx);
3267 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3268 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
3269 			count++;
3270 	}
3271 
3272 	/*
3273 	 * Insert stream header.
3274 	 */
3275 	bzero(&ush, sizeof(ush));
3276 	ush.ush_version = UMA_STREAM_VERSION;
3277 	ush.ush_maxcpus = (mp_maxid + 1);
3278 	ush.ush_count = count;
3279 	(void)sbuf_bcat(&sbuf, &ush, sizeof(ush));
3280 
3281 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3282 		LIST_FOREACH(z, &kz->uk_zones, uz_link) {
3283 			bzero(&uth, sizeof(uth));
3284 			ZONE_LOCK(z);
3285 			strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
3286 			uth.uth_align = kz->uk_align;
3287 			uth.uth_size = kz->uk_size;
3288 			uth.uth_rsize = kz->uk_rsize;
3289 			LIST_FOREACH(kl, &z->uz_kegs, kl_link) {
3290 				k = kl->kl_keg;
3291 				uth.uth_maxpages += k->uk_maxpages;
3292 				uth.uth_pages += k->uk_pages;
3293 				uth.uth_keg_free += k->uk_free;
3294 				uth.uth_limit = (k->uk_maxpages / k->uk_ppera)
3295 				    * k->uk_ipers;
3296 			}
3297 
3298 			/*
3299 			 * A zone is secondary is it is not the first entry
3300 			 * on the keg's zone list.
3301 			 */
3302 			if ((z->uz_flags & UMA_ZONE_SECONDARY) &&
3303 			    (LIST_FIRST(&kz->uk_zones) != z))
3304 				uth.uth_zone_flags = UTH_ZONE_SECONDARY;
3305 
3306 			LIST_FOREACH(bucket, &z->uz_buckets, ub_link)
3307 				uth.uth_zone_free += bucket->ub_cnt;
3308 			uth.uth_allocs = z->uz_allocs;
3309 			uth.uth_frees = z->uz_frees;
3310 			uth.uth_fails = z->uz_fails;
3311 			uth.uth_sleeps = z->uz_sleeps;
3312 			(void)sbuf_bcat(&sbuf, &uth, sizeof(uth));
3313 			/*
3314 			 * While it is not normally safe to access the cache
3315 			 * bucket pointers while not on the CPU that owns the
3316 			 * cache, we only allow the pointers to be exchanged
3317 			 * without the zone lock held, not invalidated, so
3318 			 * accept the possible race associated with bucket
3319 			 * exchange during monitoring.
3320 			 */
3321 			for (i = 0; i < (mp_maxid + 1); i++) {
3322 				bzero(&ups, sizeof(ups));
3323 				if (kz->uk_flags & UMA_ZFLAG_INTERNAL)
3324 					goto skip;
3325 				if (CPU_ABSENT(i))
3326 					goto skip;
3327 				cache = &z->uz_cpu[i];
3328 				if (cache->uc_allocbucket != NULL)
3329 					ups.ups_cache_free +=
3330 					    cache->uc_allocbucket->ub_cnt;
3331 				if (cache->uc_freebucket != NULL)
3332 					ups.ups_cache_free +=
3333 					    cache->uc_freebucket->ub_cnt;
3334 				ups.ups_allocs = cache->uc_allocs;
3335 				ups.ups_frees = cache->uc_frees;
3336 skip:
3337 				(void)sbuf_bcat(&sbuf, &ups, sizeof(ups));
3338 			}
3339 			ZONE_UNLOCK(z);
3340 		}
3341 	}
3342 	mtx_unlock(&uma_mtx);
3343 	error = sbuf_finish(&sbuf);
3344 	sbuf_delete(&sbuf);
3345 	return (error);
3346 }
3347 
3348 #ifdef DDB
3349 DB_SHOW_COMMAND(uma, db_show_uma)
3350 {
3351 	uint64_t allocs, frees, sleeps;
3352 	uma_bucket_t bucket;
3353 	uma_keg_t kz;
3354 	uma_zone_t z;
3355 	int cachefree;
3356 
3357 	db_printf("%18s %8s %8s %8s %12s %8s\n", "Zone", "Size", "Used", "Free",
3358 	    "Requests", "Sleeps");
3359 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3360 		LIST_FOREACH(z, &kz->uk_zones, uz_link) {
3361 			if (kz->uk_flags & UMA_ZFLAG_INTERNAL) {
3362 				allocs = z->uz_allocs;
3363 				frees = z->uz_frees;
3364 				sleeps = z->uz_sleeps;
3365 				cachefree = 0;
3366 			} else
3367 				uma_zone_sumstat(z, &cachefree, &allocs,
3368 				    &frees, &sleeps);
3369 			if (!((z->uz_flags & UMA_ZONE_SECONDARY) &&
3370 			    (LIST_FIRST(&kz->uk_zones) != z)))
3371 				cachefree += kz->uk_free;
3372 			LIST_FOREACH(bucket, &z->uz_buckets, ub_link)
3373 				cachefree += bucket->ub_cnt;
3374 			db_printf("%18s %8ju %8jd %8d %12ju %8ju\n", z->uz_name,
3375 			    (uintmax_t)kz->uk_size,
3376 			    (intmax_t)(allocs - frees), cachefree,
3377 			    (uintmax_t)allocs, sleeps);
3378 			if (db_pager_quit)
3379 				return;
3380 		}
3381 	}
3382 }
3383 #endif
3384