xref: /freebsd/sys/vm/uma_core.c (revision 195ebc7e9e4b129de810833791a19dfb4349d6a9)
1 /*-
2  * Copyright (c) 2002-2005, 2009 Jeffrey Roberson <jeff@FreeBSD.org>
3  * Copyright (c) 2004, 2005 Bosko Milekic <bmilekic@FreeBSD.org>
4  * Copyright (c) 2004-2006 Robert N. M. Watson
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice unmodified, this list of conditions, and the following
12  *    disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /*
30  * uma_core.c  Implementation of the Universal Memory allocator
31  *
32  * This allocator is intended to replace the multitude of similar object caches
33  * in the standard FreeBSD kernel.  The intent is to be flexible as well as
34  * effecient.  A primary design goal is to return unused memory to the rest of
35  * the system.  This will make the system as a whole more flexible due to the
36  * ability to move memory to subsystems which most need it instead of leaving
37  * pools of reserved memory unused.
38  *
39  * The basic ideas stem from similar slab/zone based allocators whose algorithms
40  * are well known.
41  *
42  */
43 
44 /*
45  * TODO:
46  *	- Improve memory usage for large allocations
47  *	- Investigate cache size adjustments
48  */
49 
50 #include <sys/cdefs.h>
51 __FBSDID("$FreeBSD$");
52 
53 /* I should really use ktr.. */
54 /*
55 #define UMA_DEBUG 1
56 #define UMA_DEBUG_ALLOC 1
57 #define UMA_DEBUG_ALLOC_1 1
58 */
59 
60 #include "opt_ddb.h"
61 #include "opt_param.h"
62 
63 #include <sys/param.h>
64 #include <sys/systm.h>
65 #include <sys/kernel.h>
66 #include <sys/types.h>
67 #include <sys/queue.h>
68 #include <sys/malloc.h>
69 #include <sys/ktr.h>
70 #include <sys/lock.h>
71 #include <sys/sysctl.h>
72 #include <sys/mutex.h>
73 #include <sys/proc.h>
74 #include <sys/sbuf.h>
75 #include <sys/smp.h>
76 #include <sys/vmmeter.h>
77 
78 #include <vm/vm.h>
79 #include <vm/vm_object.h>
80 #include <vm/vm_page.h>
81 #include <vm/vm_param.h>
82 #include <vm/vm_map.h>
83 #include <vm/vm_kern.h>
84 #include <vm/vm_extern.h>
85 #include <vm/uma.h>
86 #include <vm/uma_int.h>
87 #include <vm/uma_dbg.h>
88 
89 #include <machine/vmparam.h>
90 
91 #include <ddb/ddb.h>
92 
93 /*
94  * This is the zone and keg from which all zones are spawned.  The idea is that
95  * even the zone & keg heads are allocated from the allocator, so we use the
96  * bss section to bootstrap us.
97  */
98 static struct uma_keg masterkeg;
99 static struct uma_zone masterzone_k;
100 static struct uma_zone masterzone_z;
101 static uma_zone_t kegs = &masterzone_k;
102 static uma_zone_t zones = &masterzone_z;
103 
104 /* This is the zone from which all of uma_slab_t's are allocated. */
105 static uma_zone_t slabzone;
106 static uma_zone_t slabrefzone;	/* With refcounters (for UMA_ZONE_REFCNT) */
107 
108 /*
109  * The initial hash tables come out of this zone so they can be allocated
110  * prior to malloc coming up.
111  */
112 static uma_zone_t hashzone;
113 
114 /* The boot-time adjusted value for cache line alignment. */
115 static int uma_align_cache = 64 - 1;
116 
117 static MALLOC_DEFINE(M_UMAHASH, "UMAHash", "UMA Hash Buckets");
118 
119 /*
120  * Are we allowed to allocate buckets?
121  */
122 static int bucketdisable = 1;
123 
124 /* Linked list of all kegs in the system */
125 static LIST_HEAD(,uma_keg) uma_kegs = LIST_HEAD_INITIALIZER(&uma_kegs);
126 
127 /* This mutex protects the keg list */
128 static struct mtx uma_mtx;
129 
130 /* Linked list of boot time pages */
131 static LIST_HEAD(,uma_slab) uma_boot_pages =
132     LIST_HEAD_INITIALIZER(&uma_boot_pages);
133 
134 /* This mutex protects the boot time pages list */
135 static struct mtx uma_boot_pages_mtx;
136 
137 /* Is the VM done starting up? */
138 static int booted = 0;
139 
140 /* Maximum number of allowed items-per-slab if the slab header is OFFPAGE */
141 static u_int uma_max_ipers;
142 static u_int uma_max_ipers_ref;
143 
144 /*
145  * This is the handle used to schedule events that need to happen
146  * outside of the allocation fast path.
147  */
148 static struct callout uma_callout;
149 #define	UMA_TIMEOUT	20		/* Seconds for callout interval. */
150 
151 /*
152  * This structure is passed as the zone ctor arg so that I don't have to create
153  * a special allocation function just for zones.
154  */
155 struct uma_zctor_args {
156 	char *name;
157 	size_t size;
158 	uma_ctor ctor;
159 	uma_dtor dtor;
160 	uma_init uminit;
161 	uma_fini fini;
162 	uma_keg_t keg;
163 	int align;
164 	u_int32_t flags;
165 };
166 
167 struct uma_kctor_args {
168 	uma_zone_t zone;
169 	size_t size;
170 	uma_init uminit;
171 	uma_fini fini;
172 	int align;
173 	u_int32_t flags;
174 };
175 
176 struct uma_bucket_zone {
177 	uma_zone_t	ubz_zone;
178 	char		*ubz_name;
179 	int		ubz_entries;
180 };
181 
182 #define	BUCKET_MAX	128
183 
184 struct uma_bucket_zone bucket_zones[] = {
185 	{ NULL, "16 Bucket", 16 },
186 	{ NULL, "32 Bucket", 32 },
187 	{ NULL, "64 Bucket", 64 },
188 	{ NULL, "128 Bucket", 128 },
189 	{ NULL, NULL, 0}
190 };
191 
192 #define	BUCKET_SHIFT	4
193 #define	BUCKET_ZONES	((BUCKET_MAX >> BUCKET_SHIFT) + 1)
194 
195 /*
196  * bucket_size[] maps requested bucket sizes to zones that allocate a bucket
197  * of approximately the right size.
198  */
199 static uint8_t bucket_size[BUCKET_ZONES];
200 
201 /*
202  * Flags and enumerations to be passed to internal functions.
203  */
204 enum zfreeskip { SKIP_NONE, SKIP_DTOR, SKIP_FINI };
205 
206 #define	ZFREE_STATFAIL	0x00000001	/* Update zone failure statistic. */
207 #define	ZFREE_STATFREE	0x00000002	/* Update zone free statistic. */
208 
209 /* Prototypes.. */
210 
211 static void *obj_alloc(uma_zone_t, int, u_int8_t *, int);
212 static void *page_alloc(uma_zone_t, int, u_int8_t *, int);
213 static void *startup_alloc(uma_zone_t, int, u_int8_t *, int);
214 static void page_free(void *, int, u_int8_t);
215 static uma_slab_t keg_alloc_slab(uma_keg_t, uma_zone_t, int);
216 static void cache_drain(uma_zone_t);
217 static void bucket_drain(uma_zone_t, uma_bucket_t);
218 static void bucket_cache_drain(uma_zone_t zone);
219 static int keg_ctor(void *, int, void *, int);
220 static void keg_dtor(void *, int, void *);
221 static int zone_ctor(void *, int, void *, int);
222 static void zone_dtor(void *, int, void *);
223 static int zero_init(void *, int, int);
224 static void keg_small_init(uma_keg_t keg);
225 static void keg_large_init(uma_keg_t keg);
226 static void zone_foreach(void (*zfunc)(uma_zone_t));
227 static void zone_timeout(uma_zone_t zone);
228 static int hash_alloc(struct uma_hash *);
229 static int hash_expand(struct uma_hash *, struct uma_hash *);
230 static void hash_free(struct uma_hash *hash);
231 static void uma_timeout(void *);
232 static void uma_startup3(void);
233 static void *zone_alloc_item(uma_zone_t, void *, int);
234 static void zone_free_item(uma_zone_t, void *, void *, enum zfreeskip,
235     int);
236 static void bucket_enable(void);
237 static void bucket_init(void);
238 static uma_bucket_t bucket_alloc(int, int);
239 static void bucket_free(uma_bucket_t);
240 static void bucket_zone_drain(void);
241 static int zone_alloc_bucket(uma_zone_t zone, int flags);
242 static uma_slab_t zone_fetch_slab(uma_zone_t zone, uma_keg_t last, int flags);
243 static uma_slab_t zone_fetch_slab_multi(uma_zone_t zone, uma_keg_t last, int flags);
244 static void *slab_alloc_item(uma_zone_t zone, uma_slab_t slab);
245 static uma_keg_t uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit,
246     uma_fini fini, int align, u_int32_t flags);
247 static inline void zone_relock(uma_zone_t zone, uma_keg_t keg);
248 static inline void keg_relock(uma_keg_t keg, uma_zone_t zone);
249 
250 void uma_print_zone(uma_zone_t);
251 void uma_print_stats(void);
252 static int sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS);
253 static int sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS);
254 
255 SYSINIT(uma_startup3, SI_SUB_VM_CONF, SI_ORDER_SECOND, uma_startup3, NULL);
256 
257 SYSCTL_PROC(_vm, OID_AUTO, zone_count, CTLFLAG_RD|CTLTYPE_INT,
258     0, 0, sysctl_vm_zone_count, "I", "Number of UMA zones");
259 
260 SYSCTL_PROC(_vm, OID_AUTO, zone_stats, CTLFLAG_RD|CTLTYPE_STRUCT,
261     0, 0, sysctl_vm_zone_stats, "s,struct uma_type_header", "Zone Stats");
262 
263 /*
264  * This routine checks to see whether or not it's safe to enable buckets.
265  */
266 
267 static void
268 bucket_enable(void)
269 {
270 	if (cnt.v_free_count < cnt.v_free_min)
271 		bucketdisable = 1;
272 	else
273 		bucketdisable = 0;
274 }
275 
276 /*
277  * Initialize bucket_zones, the array of zones of buckets of various sizes.
278  *
279  * For each zone, calculate the memory required for each bucket, consisting
280  * of the header and an array of pointers.  Initialize bucket_size[] to point
281  * the range of appropriate bucket sizes at the zone.
282  */
283 static void
284 bucket_init(void)
285 {
286 	struct uma_bucket_zone *ubz;
287 	int i;
288 	int j;
289 
290 	for (i = 0, j = 0; bucket_zones[j].ubz_entries != 0; j++) {
291 		int size;
292 
293 		ubz = &bucket_zones[j];
294 		size = roundup(sizeof(struct uma_bucket), sizeof(void *));
295 		size += sizeof(void *) * ubz->ubz_entries;
296 		ubz->ubz_zone = uma_zcreate(ubz->ubz_name, size,
297 		    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR,
298 		    UMA_ZFLAG_INTERNAL | UMA_ZFLAG_BUCKET);
299 		for (; i <= ubz->ubz_entries; i += (1 << BUCKET_SHIFT))
300 			bucket_size[i >> BUCKET_SHIFT] = j;
301 	}
302 }
303 
304 /*
305  * Given a desired number of entries for a bucket, return the zone from which
306  * to allocate the bucket.
307  */
308 static struct uma_bucket_zone *
309 bucket_zone_lookup(int entries)
310 {
311 	int idx;
312 
313 	idx = howmany(entries, 1 << BUCKET_SHIFT);
314 	return (&bucket_zones[bucket_size[idx]]);
315 }
316 
317 static uma_bucket_t
318 bucket_alloc(int entries, int bflags)
319 {
320 	struct uma_bucket_zone *ubz;
321 	uma_bucket_t bucket;
322 
323 	/*
324 	 * This is to stop us from allocating per cpu buckets while we're
325 	 * running out of vm.boot_pages.  Otherwise, we would exhaust the
326 	 * boot pages.  This also prevents us from allocating buckets in
327 	 * low memory situations.
328 	 */
329 	if (bucketdisable)
330 		return (NULL);
331 
332 	ubz = bucket_zone_lookup(entries);
333 	bucket = zone_alloc_item(ubz->ubz_zone, NULL, bflags);
334 	if (bucket) {
335 #ifdef INVARIANTS
336 		bzero(bucket->ub_bucket, sizeof(void *) * ubz->ubz_entries);
337 #endif
338 		bucket->ub_cnt = 0;
339 		bucket->ub_entries = ubz->ubz_entries;
340 	}
341 
342 	return (bucket);
343 }
344 
345 static void
346 bucket_free(uma_bucket_t bucket)
347 {
348 	struct uma_bucket_zone *ubz;
349 
350 	ubz = bucket_zone_lookup(bucket->ub_entries);
351 	zone_free_item(ubz->ubz_zone, bucket, NULL, SKIP_NONE,
352 	    ZFREE_STATFREE);
353 }
354 
355 static void
356 bucket_zone_drain(void)
357 {
358 	struct uma_bucket_zone *ubz;
359 
360 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
361 		zone_drain(ubz->ubz_zone);
362 }
363 
364 static inline uma_keg_t
365 zone_first_keg(uma_zone_t zone)
366 {
367 
368 	return (LIST_FIRST(&zone->uz_kegs)->kl_keg);
369 }
370 
371 static void
372 zone_foreach_keg(uma_zone_t zone, void (*kegfn)(uma_keg_t))
373 {
374 	uma_klink_t klink;
375 
376 	LIST_FOREACH(klink, &zone->uz_kegs, kl_link)
377 		kegfn(klink->kl_keg);
378 }
379 
380 /*
381  * Routine called by timeout which is used to fire off some time interval
382  * based calculations.  (stats, hash size, etc.)
383  *
384  * Arguments:
385  *	arg   Unused
386  *
387  * Returns:
388  *	Nothing
389  */
390 static void
391 uma_timeout(void *unused)
392 {
393 	bucket_enable();
394 	zone_foreach(zone_timeout);
395 
396 	/* Reschedule this event */
397 	callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
398 }
399 
400 /*
401  * Routine to perform timeout driven calculations.  This expands the
402  * hashes and does per cpu statistics aggregation.
403  *
404  *  Returns nothing.
405  */
406 static void
407 keg_timeout(uma_keg_t keg)
408 {
409 
410 	KEG_LOCK(keg);
411 	/*
412 	 * Expand the keg hash table.
413 	 *
414 	 * This is done if the number of slabs is larger than the hash size.
415 	 * What I'm trying to do here is completely reduce collisions.  This
416 	 * may be a little aggressive.  Should I allow for two collisions max?
417 	 */
418 	if (keg->uk_flags & UMA_ZONE_HASH &&
419 	    keg->uk_pages / keg->uk_ppera >= keg->uk_hash.uh_hashsize) {
420 		struct uma_hash newhash;
421 		struct uma_hash oldhash;
422 		int ret;
423 
424 		/*
425 		 * This is so involved because allocating and freeing
426 		 * while the keg lock is held will lead to deadlock.
427 		 * I have to do everything in stages and check for
428 		 * races.
429 		 */
430 		newhash = keg->uk_hash;
431 		KEG_UNLOCK(keg);
432 		ret = hash_alloc(&newhash);
433 		KEG_LOCK(keg);
434 		if (ret) {
435 			if (hash_expand(&keg->uk_hash, &newhash)) {
436 				oldhash = keg->uk_hash;
437 				keg->uk_hash = newhash;
438 			} else
439 				oldhash = newhash;
440 
441 			KEG_UNLOCK(keg);
442 			hash_free(&oldhash);
443 			KEG_LOCK(keg);
444 		}
445 	}
446 	KEG_UNLOCK(keg);
447 }
448 
449 static void
450 zone_timeout(uma_zone_t zone)
451 {
452 
453 	zone_foreach_keg(zone, &keg_timeout);
454 }
455 
456 /*
457  * Allocate and zero fill the next sized hash table from the appropriate
458  * backing store.
459  *
460  * Arguments:
461  *	hash  A new hash structure with the old hash size in uh_hashsize
462  *
463  * Returns:
464  *	1 on sucess and 0 on failure.
465  */
466 static int
467 hash_alloc(struct uma_hash *hash)
468 {
469 	int oldsize;
470 	int alloc;
471 
472 	oldsize = hash->uh_hashsize;
473 
474 	/* We're just going to go to a power of two greater */
475 	if (oldsize)  {
476 		hash->uh_hashsize = oldsize * 2;
477 		alloc = sizeof(hash->uh_slab_hash[0]) * hash->uh_hashsize;
478 		hash->uh_slab_hash = (struct slabhead *)malloc(alloc,
479 		    M_UMAHASH, M_NOWAIT);
480 	} else {
481 		alloc = sizeof(hash->uh_slab_hash[0]) * UMA_HASH_SIZE_INIT;
482 		hash->uh_slab_hash = zone_alloc_item(hashzone, NULL,
483 		    M_WAITOK);
484 		hash->uh_hashsize = UMA_HASH_SIZE_INIT;
485 	}
486 	if (hash->uh_slab_hash) {
487 		bzero(hash->uh_slab_hash, alloc);
488 		hash->uh_hashmask = hash->uh_hashsize - 1;
489 		return (1);
490 	}
491 
492 	return (0);
493 }
494 
495 /*
496  * Expands the hash table for HASH zones.  This is done from zone_timeout
497  * to reduce collisions.  This must not be done in the regular allocation
498  * path, otherwise, we can recurse on the vm while allocating pages.
499  *
500  * Arguments:
501  *	oldhash  The hash you want to expand
502  *	newhash  The hash structure for the new table
503  *
504  * Returns:
505  *	Nothing
506  *
507  * Discussion:
508  */
509 static int
510 hash_expand(struct uma_hash *oldhash, struct uma_hash *newhash)
511 {
512 	uma_slab_t slab;
513 	int hval;
514 	int i;
515 
516 	if (!newhash->uh_slab_hash)
517 		return (0);
518 
519 	if (oldhash->uh_hashsize >= newhash->uh_hashsize)
520 		return (0);
521 
522 	/*
523 	 * I need to investigate hash algorithms for resizing without a
524 	 * full rehash.
525 	 */
526 
527 	for (i = 0; i < oldhash->uh_hashsize; i++)
528 		while (!SLIST_EMPTY(&oldhash->uh_slab_hash[i])) {
529 			slab = SLIST_FIRST(&oldhash->uh_slab_hash[i]);
530 			SLIST_REMOVE_HEAD(&oldhash->uh_slab_hash[i], us_hlink);
531 			hval = UMA_HASH(newhash, slab->us_data);
532 			SLIST_INSERT_HEAD(&newhash->uh_slab_hash[hval],
533 			    slab, us_hlink);
534 		}
535 
536 	return (1);
537 }
538 
539 /*
540  * Free the hash bucket to the appropriate backing store.
541  *
542  * Arguments:
543  *	slab_hash  The hash bucket we're freeing
544  *	hashsize   The number of entries in that hash bucket
545  *
546  * Returns:
547  *	Nothing
548  */
549 static void
550 hash_free(struct uma_hash *hash)
551 {
552 	if (hash->uh_slab_hash == NULL)
553 		return;
554 	if (hash->uh_hashsize == UMA_HASH_SIZE_INIT)
555 		zone_free_item(hashzone,
556 		    hash->uh_slab_hash, NULL, SKIP_NONE, ZFREE_STATFREE);
557 	else
558 		free(hash->uh_slab_hash, M_UMAHASH);
559 }
560 
561 /*
562  * Frees all outstanding items in a bucket
563  *
564  * Arguments:
565  *	zone   The zone to free to, must be unlocked.
566  *	bucket The free/alloc bucket with items, cpu queue must be locked.
567  *
568  * Returns:
569  *	Nothing
570  */
571 
572 static void
573 bucket_drain(uma_zone_t zone, uma_bucket_t bucket)
574 {
575 	void *item;
576 
577 	if (bucket == NULL)
578 		return;
579 
580 	while (bucket->ub_cnt > 0)  {
581 		bucket->ub_cnt--;
582 		item = bucket->ub_bucket[bucket->ub_cnt];
583 #ifdef INVARIANTS
584 		bucket->ub_bucket[bucket->ub_cnt] = NULL;
585 		KASSERT(item != NULL,
586 		    ("bucket_drain: botched ptr, item is NULL"));
587 #endif
588 		zone_free_item(zone, item, NULL, SKIP_DTOR, 0);
589 	}
590 }
591 
592 /*
593  * Drains the per cpu caches for a zone.
594  *
595  * NOTE: This may only be called while the zone is being turn down, and not
596  * during normal operation.  This is necessary in order that we do not have
597  * to migrate CPUs to drain the per-CPU caches.
598  *
599  * Arguments:
600  *	zone     The zone to drain, must be unlocked.
601  *
602  * Returns:
603  *	Nothing
604  */
605 static void
606 cache_drain(uma_zone_t zone)
607 {
608 	uma_cache_t cache;
609 	int cpu;
610 
611 	/*
612 	 * XXX: It is safe to not lock the per-CPU caches, because we're
613 	 * tearing down the zone anyway.  I.e., there will be no further use
614 	 * of the caches at this point.
615 	 *
616 	 * XXX: It would good to be able to assert that the zone is being
617 	 * torn down to prevent improper use of cache_drain().
618 	 *
619 	 * XXX: We lock the zone before passing into bucket_cache_drain() as
620 	 * it is used elsewhere.  Should the tear-down path be made special
621 	 * there in some form?
622 	 */
623 	for (cpu = 0; cpu <= mp_maxid; cpu++) {
624 		if (CPU_ABSENT(cpu))
625 			continue;
626 		cache = &zone->uz_cpu[cpu];
627 		bucket_drain(zone, cache->uc_allocbucket);
628 		bucket_drain(zone, cache->uc_freebucket);
629 		if (cache->uc_allocbucket != NULL)
630 			bucket_free(cache->uc_allocbucket);
631 		if (cache->uc_freebucket != NULL)
632 			bucket_free(cache->uc_freebucket);
633 		cache->uc_allocbucket = cache->uc_freebucket = NULL;
634 	}
635 	ZONE_LOCK(zone);
636 	bucket_cache_drain(zone);
637 	ZONE_UNLOCK(zone);
638 }
639 
640 /*
641  * Drain the cached buckets from a zone.  Expects a locked zone on entry.
642  */
643 static void
644 bucket_cache_drain(uma_zone_t zone)
645 {
646 	uma_bucket_t bucket;
647 
648 	/*
649 	 * Drain the bucket queues and free the buckets, we just keep two per
650 	 * cpu (alloc/free).
651 	 */
652 	while ((bucket = LIST_FIRST(&zone->uz_full_bucket)) != NULL) {
653 		LIST_REMOVE(bucket, ub_link);
654 		ZONE_UNLOCK(zone);
655 		bucket_drain(zone, bucket);
656 		bucket_free(bucket);
657 		ZONE_LOCK(zone);
658 	}
659 
660 	/* Now we do the free queue.. */
661 	while ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) {
662 		LIST_REMOVE(bucket, ub_link);
663 		bucket_free(bucket);
664 	}
665 }
666 
667 /*
668  * Frees pages from a keg back to the system.  This is done on demand from
669  * the pageout daemon.
670  *
671  * Returns nothing.
672  */
673 static void
674 keg_drain(uma_keg_t keg)
675 {
676 	struct slabhead freeslabs = { 0 };
677 	uma_slab_t slab;
678 	uma_slab_t n;
679 	u_int8_t flags;
680 	u_int8_t *mem;
681 	int i;
682 
683 	/*
684 	 * We don't want to take pages from statically allocated kegs at this
685 	 * time
686 	 */
687 	if (keg->uk_flags & UMA_ZONE_NOFREE || keg->uk_freef == NULL)
688 		return;
689 
690 #ifdef UMA_DEBUG
691 	printf("%s free items: %u\n", keg->uk_name, keg->uk_free);
692 #endif
693 	KEG_LOCK(keg);
694 	if (keg->uk_free == 0)
695 		goto finished;
696 
697 	slab = LIST_FIRST(&keg->uk_free_slab);
698 	while (slab) {
699 		n = LIST_NEXT(slab, us_link);
700 
701 		/* We have no where to free these to */
702 		if (slab->us_flags & UMA_SLAB_BOOT) {
703 			slab = n;
704 			continue;
705 		}
706 
707 		LIST_REMOVE(slab, us_link);
708 		keg->uk_pages -= keg->uk_ppera;
709 		keg->uk_free -= keg->uk_ipers;
710 
711 		if (keg->uk_flags & UMA_ZONE_HASH)
712 			UMA_HASH_REMOVE(&keg->uk_hash, slab, slab->us_data);
713 
714 		SLIST_INSERT_HEAD(&freeslabs, slab, us_hlink);
715 
716 		slab = n;
717 	}
718 finished:
719 	KEG_UNLOCK(keg);
720 
721 	while ((slab = SLIST_FIRST(&freeslabs)) != NULL) {
722 		SLIST_REMOVE(&freeslabs, slab, uma_slab, us_hlink);
723 		if (keg->uk_fini)
724 			for (i = 0; i < keg->uk_ipers; i++)
725 				keg->uk_fini(
726 				    slab->us_data + (keg->uk_rsize * i),
727 				    keg->uk_size);
728 		flags = slab->us_flags;
729 		mem = slab->us_data;
730 
731 		if (keg->uk_flags & UMA_ZONE_VTOSLAB) {
732 			vm_object_t obj;
733 
734 			if (flags & UMA_SLAB_KMEM)
735 				obj = kmem_object;
736 			else if (flags & UMA_SLAB_KERNEL)
737 				obj = kernel_object;
738 			else
739 				obj = NULL;
740 			for (i = 0; i < keg->uk_ppera; i++)
741 				vsetobj((vm_offset_t)mem + (i * PAGE_SIZE),
742 				    obj);
743 		}
744 		if (keg->uk_flags & UMA_ZONE_OFFPAGE)
745 			zone_free_item(keg->uk_slabzone, slab, NULL,
746 			    SKIP_NONE, ZFREE_STATFREE);
747 #ifdef UMA_DEBUG
748 		printf("%s: Returning %d bytes.\n",
749 		    keg->uk_name, UMA_SLAB_SIZE * keg->uk_ppera);
750 #endif
751 		keg->uk_freef(mem, UMA_SLAB_SIZE * keg->uk_ppera, flags);
752 	}
753 }
754 
755 static void
756 zone_drain_wait(uma_zone_t zone, int waitok)
757 {
758 
759 	/*
760 	 * Set draining to interlock with zone_dtor() so we can release our
761 	 * locks as we go.  Only dtor() should do a WAITOK call since it
762 	 * is the only call that knows the structure will still be available
763 	 * when it wakes up.
764 	 */
765 	ZONE_LOCK(zone);
766 	while (zone->uz_flags & UMA_ZFLAG_DRAINING) {
767 		if (waitok == M_NOWAIT)
768 			goto out;
769 		mtx_unlock(&uma_mtx);
770 		msleep(zone, zone->uz_lock, PVM, "zonedrain", 1);
771 		mtx_lock(&uma_mtx);
772 	}
773 	zone->uz_flags |= UMA_ZFLAG_DRAINING;
774 	bucket_cache_drain(zone);
775 	ZONE_UNLOCK(zone);
776 	/*
777 	 * The DRAINING flag protects us from being freed while
778 	 * we're running.  Normally the uma_mtx would protect us but we
779 	 * must be able to release and acquire the right lock for each keg.
780 	 */
781 	zone_foreach_keg(zone, &keg_drain);
782 	ZONE_LOCK(zone);
783 	zone->uz_flags &= ~UMA_ZFLAG_DRAINING;
784 	wakeup(zone);
785 out:
786 	ZONE_UNLOCK(zone);
787 }
788 
789 void
790 zone_drain(uma_zone_t zone)
791 {
792 
793 	zone_drain_wait(zone, M_NOWAIT);
794 }
795 
796 /*
797  * Allocate a new slab for a keg.  This does not insert the slab onto a list.
798  *
799  * Arguments:
800  *	wait  Shall we wait?
801  *
802  * Returns:
803  *	The slab that was allocated or NULL if there is no memory and the
804  *	caller specified M_NOWAIT.
805  */
806 static uma_slab_t
807 keg_alloc_slab(uma_keg_t keg, uma_zone_t zone, int wait)
808 {
809 	uma_slabrefcnt_t slabref;
810 	uma_alloc allocf;
811 	uma_slab_t slab;
812 	u_int8_t *mem;
813 	u_int8_t flags;
814 	int i;
815 
816 	mtx_assert(&keg->uk_lock, MA_OWNED);
817 	slab = NULL;
818 
819 #ifdef UMA_DEBUG
820 	printf("slab_zalloc:  Allocating a new slab for %s\n", keg->uk_name);
821 #endif
822 	allocf = keg->uk_allocf;
823 	KEG_UNLOCK(keg);
824 
825 	if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
826 		slab = zone_alloc_item(keg->uk_slabzone, NULL, wait);
827 		if (slab == NULL) {
828 			KEG_LOCK(keg);
829 			return NULL;
830 		}
831 	}
832 
833 	/*
834 	 * This reproduces the old vm_zone behavior of zero filling pages the
835 	 * first time they are added to a zone.
836 	 *
837 	 * Malloced items are zeroed in uma_zalloc.
838 	 */
839 
840 	if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
841 		wait |= M_ZERO;
842 	else
843 		wait &= ~M_ZERO;
844 
845 	/* zone is passed for legacy reasons. */
846 	mem = allocf(zone, keg->uk_ppera * UMA_SLAB_SIZE, &flags, wait);
847 	if (mem == NULL) {
848 		if (keg->uk_flags & UMA_ZONE_OFFPAGE)
849 			zone_free_item(keg->uk_slabzone, slab, NULL,
850 			    SKIP_NONE, ZFREE_STATFREE);
851 		KEG_LOCK(keg);
852 		return (NULL);
853 	}
854 
855 	/* Point the slab into the allocated memory */
856 	if (!(keg->uk_flags & UMA_ZONE_OFFPAGE))
857 		slab = (uma_slab_t )(mem + keg->uk_pgoff);
858 
859 	if (keg->uk_flags & UMA_ZONE_VTOSLAB)
860 		for (i = 0; i < keg->uk_ppera; i++)
861 			vsetslab((vm_offset_t)mem + (i * PAGE_SIZE), slab);
862 
863 	slab->us_keg = keg;
864 	slab->us_data = mem;
865 	slab->us_freecount = keg->uk_ipers;
866 	slab->us_firstfree = 0;
867 	slab->us_flags = flags;
868 
869 	if (keg->uk_flags & UMA_ZONE_REFCNT) {
870 		slabref = (uma_slabrefcnt_t)slab;
871 		for (i = 0; i < keg->uk_ipers; i++) {
872 			slabref->us_freelist[i].us_refcnt = 0;
873 			slabref->us_freelist[i].us_item = i+1;
874 		}
875 	} else {
876 		for (i = 0; i < keg->uk_ipers; i++)
877 			slab->us_freelist[i].us_item = i+1;
878 	}
879 
880 	if (keg->uk_init != NULL) {
881 		for (i = 0; i < keg->uk_ipers; i++)
882 			if (keg->uk_init(slab->us_data + (keg->uk_rsize * i),
883 			    keg->uk_size, wait) != 0)
884 				break;
885 		if (i != keg->uk_ipers) {
886 			if (keg->uk_fini != NULL) {
887 				for (i--; i > -1; i--)
888 					keg->uk_fini(slab->us_data +
889 					    (keg->uk_rsize * i),
890 					    keg->uk_size);
891 			}
892 			if (keg->uk_flags & UMA_ZONE_VTOSLAB) {
893 				vm_object_t obj;
894 
895 				if (flags & UMA_SLAB_KMEM)
896 					obj = kmem_object;
897 				else if (flags & UMA_SLAB_KERNEL)
898 					obj = kernel_object;
899 				else
900 					obj = NULL;
901 				for (i = 0; i < keg->uk_ppera; i++)
902 					vsetobj((vm_offset_t)mem +
903 					    (i * PAGE_SIZE), obj);
904 			}
905 			if (keg->uk_flags & UMA_ZONE_OFFPAGE)
906 				zone_free_item(keg->uk_slabzone, slab,
907 				    NULL, SKIP_NONE, ZFREE_STATFREE);
908 			keg->uk_freef(mem, UMA_SLAB_SIZE * keg->uk_ppera,
909 			    flags);
910 			KEG_LOCK(keg);
911 			return (NULL);
912 		}
913 	}
914 	KEG_LOCK(keg);
915 
916 	if (keg->uk_flags & UMA_ZONE_HASH)
917 		UMA_HASH_INSERT(&keg->uk_hash, slab, mem);
918 
919 	keg->uk_pages += keg->uk_ppera;
920 	keg->uk_free += keg->uk_ipers;
921 
922 	return (slab);
923 }
924 
925 /*
926  * This function is intended to be used early on in place of page_alloc() so
927  * that we may use the boot time page cache to satisfy allocations before
928  * the VM is ready.
929  */
930 static void *
931 startup_alloc(uma_zone_t zone, int bytes, u_int8_t *pflag, int wait)
932 {
933 	uma_keg_t keg;
934 	uma_slab_t tmps;
935 
936 	keg = zone_first_keg(zone);
937 
938 	/*
939 	 * Check our small startup cache to see if it has pages remaining.
940 	 */
941 	mtx_lock(&uma_boot_pages_mtx);
942 	if ((tmps = LIST_FIRST(&uma_boot_pages)) != NULL) {
943 		LIST_REMOVE(tmps, us_link);
944 		mtx_unlock(&uma_boot_pages_mtx);
945 		*pflag = tmps->us_flags;
946 		return (tmps->us_data);
947 	}
948 	mtx_unlock(&uma_boot_pages_mtx);
949 	if (booted == 0)
950 		panic("UMA: Increase vm.boot_pages");
951 	/*
952 	 * Now that we've booted reset these users to their real allocator.
953 	 */
954 #ifdef UMA_MD_SMALL_ALLOC
955 	keg->uk_allocf = uma_small_alloc;
956 #else
957 	keg->uk_allocf = page_alloc;
958 #endif
959 	return keg->uk_allocf(zone, bytes, pflag, wait);
960 }
961 
962 /*
963  * Allocates a number of pages from the system
964  *
965  * Arguments:
966  *	bytes  The number of bytes requested
967  *	wait  Shall we wait?
968  *
969  * Returns:
970  *	A pointer to the alloced memory or possibly
971  *	NULL if M_NOWAIT is set.
972  */
973 static void *
974 page_alloc(uma_zone_t zone, int bytes, u_int8_t *pflag, int wait)
975 {
976 	void *p;	/* Returned page */
977 
978 	*pflag = UMA_SLAB_KMEM;
979 	p = (void *) kmem_malloc(kmem_map, bytes, wait);
980 
981 	return (p);
982 }
983 
984 /*
985  * Allocates a number of pages from within an object
986  *
987  * Arguments:
988  *	bytes  The number of bytes requested
989  *	wait   Shall we wait?
990  *
991  * Returns:
992  *	A pointer to the alloced memory or possibly
993  *	NULL if M_NOWAIT is set.
994  */
995 static void *
996 obj_alloc(uma_zone_t zone, int bytes, u_int8_t *flags, int wait)
997 {
998 	vm_object_t object;
999 	vm_offset_t retkva, zkva;
1000 	vm_page_t p;
1001 	int pages, startpages;
1002 	uma_keg_t keg;
1003 
1004 	keg = zone_first_keg(zone);
1005 	object = keg->uk_obj;
1006 	retkva = 0;
1007 
1008 	/*
1009 	 * This looks a little weird since we're getting one page at a time.
1010 	 */
1011 	VM_OBJECT_LOCK(object);
1012 	p = TAILQ_LAST(&object->memq, pglist);
1013 	pages = p != NULL ? p->pindex + 1 : 0;
1014 	startpages = pages;
1015 	zkva = keg->uk_kva + pages * PAGE_SIZE;
1016 	for (; bytes > 0; bytes -= PAGE_SIZE) {
1017 		p = vm_page_alloc(object, pages,
1018 		    VM_ALLOC_INTERRUPT | VM_ALLOC_WIRED);
1019 		if (p == NULL) {
1020 			if (pages != startpages)
1021 				pmap_qremove(retkva, pages - startpages);
1022 			while (pages != startpages) {
1023 				pages--;
1024 				p = TAILQ_LAST(&object->memq, pglist);
1025 				vm_page_lock_queues();
1026 				vm_page_unwire(p, 0);
1027 				vm_page_free(p);
1028 				vm_page_unlock_queues();
1029 			}
1030 			retkva = 0;
1031 			goto done;
1032 		}
1033 		pmap_qenter(zkva, &p, 1);
1034 		if (retkva == 0)
1035 			retkva = zkva;
1036 		zkva += PAGE_SIZE;
1037 		pages += 1;
1038 	}
1039 done:
1040 	VM_OBJECT_UNLOCK(object);
1041 	*flags = UMA_SLAB_PRIV;
1042 
1043 	return ((void *)retkva);
1044 }
1045 
1046 /*
1047  * Frees a number of pages to the system
1048  *
1049  * Arguments:
1050  *	mem   A pointer to the memory to be freed
1051  *	size  The size of the memory being freed
1052  *	flags The original p->us_flags field
1053  *
1054  * Returns:
1055  *	Nothing
1056  */
1057 static void
1058 page_free(void *mem, int size, u_int8_t flags)
1059 {
1060 	vm_map_t map;
1061 
1062 	if (flags & UMA_SLAB_KMEM)
1063 		map = kmem_map;
1064 	else
1065 		panic("UMA: page_free used with invalid flags %d\n", flags);
1066 
1067 	kmem_free(map, (vm_offset_t)mem, size);
1068 }
1069 
1070 /*
1071  * Zero fill initializer
1072  *
1073  * Arguments/Returns follow uma_init specifications
1074  */
1075 static int
1076 zero_init(void *mem, int size, int flags)
1077 {
1078 	bzero(mem, size);
1079 	return (0);
1080 }
1081 
1082 /*
1083  * Finish creating a small uma keg.  This calculates ipers, and the keg size.
1084  *
1085  * Arguments
1086  *	keg  The zone we should initialize
1087  *
1088  * Returns
1089  *	Nothing
1090  */
1091 static void
1092 keg_small_init(uma_keg_t keg)
1093 {
1094 	u_int rsize;
1095 	u_int memused;
1096 	u_int wastedspace;
1097 	u_int shsize;
1098 
1099 	KASSERT(keg != NULL, ("Keg is null in keg_small_init"));
1100 	rsize = keg->uk_size;
1101 
1102 	if (rsize < UMA_SMALLEST_UNIT)
1103 		rsize = UMA_SMALLEST_UNIT;
1104 	if (rsize & keg->uk_align)
1105 		rsize = (rsize & ~keg->uk_align) + (keg->uk_align + 1);
1106 
1107 	keg->uk_rsize = rsize;
1108 	keg->uk_ppera = 1;
1109 
1110 	if (keg->uk_flags & UMA_ZONE_REFCNT) {
1111 		rsize += UMA_FRITMREF_SZ;	/* linkage & refcnt */
1112 		shsize = sizeof(struct uma_slab_refcnt);
1113 	} else {
1114 		rsize += UMA_FRITM_SZ;	/* Account for linkage */
1115 		shsize = sizeof(struct uma_slab);
1116 	}
1117 
1118 	keg->uk_ipers = (UMA_SLAB_SIZE - shsize) / rsize;
1119 	KASSERT(keg->uk_ipers != 0, ("keg_small_init: ipers is 0"));
1120 	memused = keg->uk_ipers * rsize + shsize;
1121 	wastedspace = UMA_SLAB_SIZE - memused;
1122 
1123 	/*
1124 	 * We can't do OFFPAGE if we're internal or if we've been
1125 	 * asked to not go to the VM for buckets.  If we do this we
1126 	 * may end up going to the VM (kmem_map) for slabs which we
1127 	 * do not want to do if we're UMA_ZFLAG_CACHEONLY as a
1128 	 * result of UMA_ZONE_VM, which clearly forbids it.
1129 	 */
1130 	if ((keg->uk_flags & UMA_ZFLAG_INTERNAL) ||
1131 	    (keg->uk_flags & UMA_ZFLAG_CACHEONLY))
1132 		return;
1133 
1134 	if ((wastedspace >= UMA_MAX_WASTE) &&
1135 	    (keg->uk_ipers < (UMA_SLAB_SIZE / keg->uk_rsize))) {
1136 		keg->uk_ipers = UMA_SLAB_SIZE / keg->uk_rsize;
1137 		KASSERT(keg->uk_ipers <= 255,
1138 		    ("keg_small_init: keg->uk_ipers too high!"));
1139 #ifdef UMA_DEBUG
1140 		printf("UMA decided we need offpage slab headers for "
1141 		    "keg: %s, calculated wastedspace = %d, "
1142 		    "maximum wasted space allowed = %d, "
1143 		    "calculated ipers = %d, "
1144 		    "new wasted space = %d\n", keg->uk_name, wastedspace,
1145 		    UMA_MAX_WASTE, keg->uk_ipers,
1146 		    UMA_SLAB_SIZE - keg->uk_ipers * keg->uk_rsize);
1147 #endif
1148 		keg->uk_flags |= UMA_ZONE_OFFPAGE;
1149 		if ((keg->uk_flags & UMA_ZONE_VTOSLAB) == 0)
1150 			keg->uk_flags |= UMA_ZONE_HASH;
1151 	}
1152 }
1153 
1154 /*
1155  * Finish creating a large (> UMA_SLAB_SIZE) uma kegs.  Just give in and do
1156  * OFFPAGE for now.  When I can allow for more dynamic slab sizes this will be
1157  * more complicated.
1158  *
1159  * Arguments
1160  *	keg  The keg we should initialize
1161  *
1162  * Returns
1163  *	Nothing
1164  */
1165 static void
1166 keg_large_init(uma_keg_t keg)
1167 {
1168 	int pages;
1169 
1170 	KASSERT(keg != NULL, ("Keg is null in keg_large_init"));
1171 	KASSERT((keg->uk_flags & UMA_ZFLAG_CACHEONLY) == 0,
1172 	    ("keg_large_init: Cannot large-init a UMA_ZFLAG_CACHEONLY keg"));
1173 
1174 	pages = keg->uk_size / UMA_SLAB_SIZE;
1175 
1176 	/* Account for remainder */
1177 	if ((pages * UMA_SLAB_SIZE) < keg->uk_size)
1178 		pages++;
1179 
1180 	keg->uk_ppera = pages;
1181 	keg->uk_ipers = 1;
1182 
1183 	keg->uk_flags |= UMA_ZONE_OFFPAGE;
1184 	if ((keg->uk_flags & UMA_ZONE_VTOSLAB) == 0)
1185 		keg->uk_flags |= UMA_ZONE_HASH;
1186 
1187 	keg->uk_rsize = keg->uk_size;
1188 }
1189 
1190 static void
1191 keg_cachespread_init(uma_keg_t keg)
1192 {
1193 	int alignsize;
1194 	int trailer;
1195 	int pages;
1196 	int rsize;
1197 
1198 	alignsize = keg->uk_align + 1;
1199 	rsize = keg->uk_size;
1200 	/*
1201 	 * We want one item to start on every align boundary in a page.  To
1202 	 * do this we will span pages.  We will also extend the item by the
1203 	 * size of align if it is an even multiple of align.  Otherwise, it
1204 	 * would fall on the same boundary every time.
1205 	 */
1206 	if (rsize & keg->uk_align)
1207 		rsize = (rsize & ~keg->uk_align) + alignsize;
1208 	if ((rsize & alignsize) == 0)
1209 		rsize += alignsize;
1210 	trailer = rsize - keg->uk_size;
1211 	pages = (rsize * (PAGE_SIZE / alignsize)) / PAGE_SIZE;
1212 	pages = MIN(pages, (128 * 1024) / PAGE_SIZE);
1213 	keg->uk_rsize = rsize;
1214 	keg->uk_ppera = pages;
1215 	keg->uk_ipers = ((pages * PAGE_SIZE) + trailer) / rsize;
1216 	keg->uk_flags |= UMA_ZONE_OFFPAGE | UMA_ZONE_VTOSLAB;
1217 	KASSERT(keg->uk_ipers <= uma_max_ipers,
1218 	    ("keg_small_init: keg->uk_ipers too high(%d) increase max_ipers",
1219 	    keg->uk_ipers));
1220 }
1221 
1222 /*
1223  * Keg header ctor.  This initializes all fields, locks, etc.  And inserts
1224  * the keg onto the global keg list.
1225  *
1226  * Arguments/Returns follow uma_ctor specifications
1227  *	udata  Actually uma_kctor_args
1228  */
1229 static int
1230 keg_ctor(void *mem, int size, void *udata, int flags)
1231 {
1232 	struct uma_kctor_args *arg = udata;
1233 	uma_keg_t keg = mem;
1234 	uma_zone_t zone;
1235 
1236 	bzero(keg, size);
1237 	keg->uk_size = arg->size;
1238 	keg->uk_init = arg->uminit;
1239 	keg->uk_fini = arg->fini;
1240 	keg->uk_align = arg->align;
1241 	keg->uk_free = 0;
1242 	keg->uk_pages = 0;
1243 	keg->uk_flags = arg->flags;
1244 	keg->uk_allocf = page_alloc;
1245 	keg->uk_freef = page_free;
1246 	keg->uk_recurse = 0;
1247 	keg->uk_slabzone = NULL;
1248 
1249 	/*
1250 	 * The master zone is passed to us at keg-creation time.
1251 	 */
1252 	zone = arg->zone;
1253 	keg->uk_name = zone->uz_name;
1254 
1255 	if (arg->flags & UMA_ZONE_VM)
1256 		keg->uk_flags |= UMA_ZFLAG_CACHEONLY;
1257 
1258 	if (arg->flags & UMA_ZONE_ZINIT)
1259 		keg->uk_init = zero_init;
1260 
1261 	if (arg->flags & UMA_ZONE_REFCNT || arg->flags & UMA_ZONE_MALLOC)
1262 		keg->uk_flags |= UMA_ZONE_VTOSLAB;
1263 
1264 	/*
1265 	 * The +UMA_FRITM_SZ added to uk_size is to account for the
1266 	 * linkage that is added to the size in keg_small_init().  If
1267 	 * we don't account for this here then we may end up in
1268 	 * keg_small_init() with a calculated 'ipers' of 0.
1269 	 */
1270 	if (keg->uk_flags & UMA_ZONE_REFCNT) {
1271 		if (keg->uk_flags & UMA_ZONE_CACHESPREAD)
1272 			keg_cachespread_init(keg);
1273 		else if ((keg->uk_size+UMA_FRITMREF_SZ) >
1274 		    (UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt)))
1275 			keg_large_init(keg);
1276 		else
1277 			keg_small_init(keg);
1278 	} else {
1279 		if (keg->uk_flags & UMA_ZONE_CACHESPREAD)
1280 			keg_cachespread_init(keg);
1281 		else if ((keg->uk_size+UMA_FRITM_SZ) >
1282 		    (UMA_SLAB_SIZE - sizeof(struct uma_slab)))
1283 			keg_large_init(keg);
1284 		else
1285 			keg_small_init(keg);
1286 	}
1287 
1288 	if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
1289 		if (keg->uk_flags & UMA_ZONE_REFCNT)
1290 			keg->uk_slabzone = slabrefzone;
1291 		else
1292 			keg->uk_slabzone = slabzone;
1293 	}
1294 
1295 	/*
1296 	 * If we haven't booted yet we need allocations to go through the
1297 	 * startup cache until the vm is ready.
1298 	 */
1299 	if (keg->uk_ppera == 1) {
1300 #ifdef UMA_MD_SMALL_ALLOC
1301 		keg->uk_allocf = uma_small_alloc;
1302 		keg->uk_freef = uma_small_free;
1303 #endif
1304 		if (booted == 0)
1305 			keg->uk_allocf = startup_alloc;
1306 	}
1307 
1308 	/*
1309 	 * Initialize keg's lock (shared among zones).
1310 	 */
1311 	if (arg->flags & UMA_ZONE_MTXCLASS)
1312 		KEG_LOCK_INIT(keg, 1);
1313 	else
1314 		KEG_LOCK_INIT(keg, 0);
1315 
1316 	/*
1317 	 * If we're putting the slab header in the actual page we need to
1318 	 * figure out where in each page it goes.  This calculates a right
1319 	 * justified offset into the memory on an ALIGN_PTR boundary.
1320 	 */
1321 	if (!(keg->uk_flags & UMA_ZONE_OFFPAGE)) {
1322 		u_int totsize;
1323 
1324 		/* Size of the slab struct and free list */
1325 		if (keg->uk_flags & UMA_ZONE_REFCNT)
1326 			totsize = sizeof(struct uma_slab_refcnt) +
1327 			    keg->uk_ipers * UMA_FRITMREF_SZ;
1328 		else
1329 			totsize = sizeof(struct uma_slab) +
1330 			    keg->uk_ipers * UMA_FRITM_SZ;
1331 
1332 		if (totsize & UMA_ALIGN_PTR)
1333 			totsize = (totsize & ~UMA_ALIGN_PTR) +
1334 			    (UMA_ALIGN_PTR + 1);
1335 		keg->uk_pgoff = UMA_SLAB_SIZE - totsize;
1336 
1337 		if (keg->uk_flags & UMA_ZONE_REFCNT)
1338 			totsize = keg->uk_pgoff + sizeof(struct uma_slab_refcnt)
1339 			    + keg->uk_ipers * UMA_FRITMREF_SZ;
1340 		else
1341 			totsize = keg->uk_pgoff + sizeof(struct uma_slab)
1342 			    + keg->uk_ipers * UMA_FRITM_SZ;
1343 
1344 		/*
1345 		 * The only way the following is possible is if with our
1346 		 * UMA_ALIGN_PTR adjustments we are now bigger than
1347 		 * UMA_SLAB_SIZE.  I haven't checked whether this is
1348 		 * mathematically possible for all cases, so we make
1349 		 * sure here anyway.
1350 		 */
1351 		if (totsize > UMA_SLAB_SIZE) {
1352 			printf("zone %s ipers %d rsize %d size %d\n",
1353 			    zone->uz_name, keg->uk_ipers, keg->uk_rsize,
1354 			    keg->uk_size);
1355 			panic("UMA slab won't fit.\n");
1356 		}
1357 	}
1358 
1359 	if (keg->uk_flags & UMA_ZONE_HASH)
1360 		hash_alloc(&keg->uk_hash);
1361 
1362 #ifdef UMA_DEBUG
1363 	printf("UMA: %s(%p) size %d(%d) flags %d ipers %d ppera %d out %d free %d\n",
1364 	    zone->uz_name, zone, keg->uk_size, keg->uk_rsize, keg->uk_flags,
1365 	    keg->uk_ipers, keg->uk_ppera,
1366 	    (keg->uk_ipers * keg->uk_pages) - keg->uk_free, keg->uk_free);
1367 #endif
1368 
1369 	LIST_INSERT_HEAD(&keg->uk_zones, zone, uz_link);
1370 
1371 	mtx_lock(&uma_mtx);
1372 	LIST_INSERT_HEAD(&uma_kegs, keg, uk_link);
1373 	mtx_unlock(&uma_mtx);
1374 	return (0);
1375 }
1376 
1377 /*
1378  * Zone header ctor.  This initializes all fields, locks, etc.
1379  *
1380  * Arguments/Returns follow uma_ctor specifications
1381  *	udata  Actually uma_zctor_args
1382  */
1383 static int
1384 zone_ctor(void *mem, int size, void *udata, int flags)
1385 {
1386 	struct uma_zctor_args *arg = udata;
1387 	uma_zone_t zone = mem;
1388 	uma_zone_t z;
1389 	uma_keg_t keg;
1390 
1391 	bzero(zone, size);
1392 	zone->uz_name = arg->name;
1393 	zone->uz_ctor = arg->ctor;
1394 	zone->uz_dtor = arg->dtor;
1395 	zone->uz_slab = zone_fetch_slab;
1396 	zone->uz_init = NULL;
1397 	zone->uz_fini = NULL;
1398 	zone->uz_allocs = 0;
1399 	zone->uz_frees = 0;
1400 	zone->uz_fails = 0;
1401 	zone->uz_fills = zone->uz_count = 0;
1402 	zone->uz_flags = 0;
1403 	keg = arg->keg;
1404 
1405 	if (arg->flags & UMA_ZONE_SECONDARY) {
1406 		KASSERT(arg->keg != NULL, ("Secondary zone on zero'd keg"));
1407 		zone->uz_init = arg->uminit;
1408 		zone->uz_fini = arg->fini;
1409 		zone->uz_lock = &keg->uk_lock;
1410 		zone->uz_flags |= UMA_ZONE_SECONDARY;
1411 		mtx_lock(&uma_mtx);
1412 		ZONE_LOCK(zone);
1413 		LIST_FOREACH(z, &keg->uk_zones, uz_link) {
1414 			if (LIST_NEXT(z, uz_link) == NULL) {
1415 				LIST_INSERT_AFTER(z, zone, uz_link);
1416 				break;
1417 			}
1418 		}
1419 		ZONE_UNLOCK(zone);
1420 		mtx_unlock(&uma_mtx);
1421 	} else if (keg == NULL) {
1422 		if ((keg = uma_kcreate(zone, arg->size, arg->uminit, arg->fini,
1423 		    arg->align, arg->flags)) == NULL)
1424 			return (ENOMEM);
1425 	} else {
1426 		struct uma_kctor_args karg;
1427 		int error;
1428 
1429 		/* We should only be here from uma_startup() */
1430 		karg.size = arg->size;
1431 		karg.uminit = arg->uminit;
1432 		karg.fini = arg->fini;
1433 		karg.align = arg->align;
1434 		karg.flags = arg->flags;
1435 		karg.zone = zone;
1436 		error = keg_ctor(arg->keg, sizeof(struct uma_keg), &karg,
1437 		    flags);
1438 		if (error)
1439 			return (error);
1440 	}
1441 	/*
1442 	 * Link in the first keg.
1443 	 */
1444 	zone->uz_klink.kl_keg = keg;
1445 	LIST_INSERT_HEAD(&zone->uz_kegs, &zone->uz_klink, kl_link);
1446 	zone->uz_lock = &keg->uk_lock;
1447 	zone->uz_size = keg->uk_size;
1448 	zone->uz_flags |= (keg->uk_flags &
1449 	    (UMA_ZONE_INHERIT | UMA_ZFLAG_INHERIT));
1450 
1451 	/*
1452 	 * Some internal zones don't have room allocated for the per cpu
1453 	 * caches.  If we're internal, bail out here.
1454 	 */
1455 	if (keg->uk_flags & UMA_ZFLAG_INTERNAL) {
1456 		KASSERT((zone->uz_flags & UMA_ZONE_SECONDARY) == 0,
1457 		    ("Secondary zone requested UMA_ZFLAG_INTERNAL"));
1458 		return (0);
1459 	}
1460 
1461 	if (keg->uk_flags & UMA_ZONE_MAXBUCKET)
1462 		zone->uz_count = BUCKET_MAX;
1463 	else if (keg->uk_ipers <= BUCKET_MAX)
1464 		zone->uz_count = keg->uk_ipers;
1465 	else
1466 		zone->uz_count = BUCKET_MAX;
1467 	return (0);
1468 }
1469 
1470 /*
1471  * Keg header dtor.  This frees all data, destroys locks, frees the hash
1472  * table and removes the keg from the global list.
1473  *
1474  * Arguments/Returns follow uma_dtor specifications
1475  *	udata  unused
1476  */
1477 static void
1478 keg_dtor(void *arg, int size, void *udata)
1479 {
1480 	uma_keg_t keg;
1481 
1482 	keg = (uma_keg_t)arg;
1483 	KEG_LOCK(keg);
1484 	if (keg->uk_free != 0) {
1485 		printf("Freed UMA keg was not empty (%d items). "
1486 		    " Lost %d pages of memory.\n",
1487 		    keg->uk_free, keg->uk_pages);
1488 	}
1489 	KEG_UNLOCK(keg);
1490 
1491 	hash_free(&keg->uk_hash);
1492 
1493 	KEG_LOCK_FINI(keg);
1494 }
1495 
1496 /*
1497  * Zone header dtor.
1498  *
1499  * Arguments/Returns follow uma_dtor specifications
1500  *	udata  unused
1501  */
1502 static void
1503 zone_dtor(void *arg, int size, void *udata)
1504 {
1505 	uma_klink_t klink;
1506 	uma_zone_t zone;
1507 	uma_keg_t keg;
1508 
1509 	zone = (uma_zone_t)arg;
1510 	keg = zone_first_keg(zone);
1511 
1512 	if (!(zone->uz_flags & UMA_ZFLAG_INTERNAL))
1513 		cache_drain(zone);
1514 
1515 	mtx_lock(&uma_mtx);
1516 	LIST_REMOVE(zone, uz_link);
1517 	mtx_unlock(&uma_mtx);
1518 	/*
1519 	 * XXX there are some races here where
1520 	 * the zone can be drained but zone lock
1521 	 * released and then refilled before we
1522 	 * remove it... we dont care for now
1523 	 */
1524 	zone_drain_wait(zone, M_WAITOK);
1525 	/*
1526 	 * Unlink all of our kegs.
1527 	 */
1528 	while ((klink = LIST_FIRST(&zone->uz_kegs)) != NULL) {
1529 		klink->kl_keg = NULL;
1530 		LIST_REMOVE(klink, kl_link);
1531 		if (klink == &zone->uz_klink)
1532 			continue;
1533 		free(klink, M_TEMP);
1534 	}
1535 	/*
1536 	 * We only destroy kegs from non secondary zones.
1537 	 */
1538 	if ((zone->uz_flags & UMA_ZONE_SECONDARY) == 0)  {
1539 		mtx_lock(&uma_mtx);
1540 		LIST_REMOVE(keg, uk_link);
1541 		mtx_unlock(&uma_mtx);
1542 		zone_free_item(kegs, keg, NULL, SKIP_NONE,
1543 		    ZFREE_STATFREE);
1544 	}
1545 }
1546 
1547 /*
1548  * Traverses every zone in the system and calls a callback
1549  *
1550  * Arguments:
1551  *	zfunc  A pointer to a function which accepts a zone
1552  *		as an argument.
1553  *
1554  * Returns:
1555  *	Nothing
1556  */
1557 static void
1558 zone_foreach(void (*zfunc)(uma_zone_t))
1559 {
1560 	uma_keg_t keg;
1561 	uma_zone_t zone;
1562 
1563 	mtx_lock(&uma_mtx);
1564 	LIST_FOREACH(keg, &uma_kegs, uk_link) {
1565 		LIST_FOREACH(zone, &keg->uk_zones, uz_link)
1566 			zfunc(zone);
1567 	}
1568 	mtx_unlock(&uma_mtx);
1569 }
1570 
1571 /* Public functions */
1572 /* See uma.h */
1573 void
1574 uma_startup(void *bootmem, int boot_pages)
1575 {
1576 	struct uma_zctor_args args;
1577 	uma_slab_t slab;
1578 	u_int slabsize;
1579 	u_int objsize, totsize, wsize;
1580 	int i;
1581 
1582 #ifdef UMA_DEBUG
1583 	printf("Creating uma keg headers zone and keg.\n");
1584 #endif
1585 	mtx_init(&uma_mtx, "UMA lock", NULL, MTX_DEF);
1586 
1587 	/*
1588 	 * Figure out the maximum number of items-per-slab we'll have if
1589 	 * we're using the OFFPAGE slab header to track free items, given
1590 	 * all possible object sizes and the maximum desired wastage
1591 	 * (UMA_MAX_WASTE).
1592 	 *
1593 	 * We iterate until we find an object size for
1594 	 * which the calculated wastage in keg_small_init() will be
1595 	 * enough to warrant OFFPAGE.  Since wastedspace versus objsize
1596 	 * is an overall increasing see-saw function, we find the smallest
1597 	 * objsize such that the wastage is always acceptable for objects
1598 	 * with that objsize or smaller.  Since a smaller objsize always
1599 	 * generates a larger possible uma_max_ipers, we use this computed
1600 	 * objsize to calculate the largest ipers possible.  Since the
1601 	 * ipers calculated for OFFPAGE slab headers is always larger than
1602 	 * the ipers initially calculated in keg_small_init(), we use
1603 	 * the former's equation (UMA_SLAB_SIZE / keg->uk_rsize) to
1604 	 * obtain the maximum ipers possible for offpage slab headers.
1605 	 *
1606 	 * It should be noted that ipers versus objsize is an inversly
1607 	 * proportional function which drops off rather quickly so as
1608 	 * long as our UMA_MAX_WASTE is such that the objsize we calculate
1609 	 * falls into the portion of the inverse relation AFTER the steep
1610 	 * falloff, then uma_max_ipers shouldn't be too high (~10 on i386).
1611 	 *
1612 	 * Note that we have 8-bits (1 byte) to use as a freelist index
1613 	 * inside the actual slab header itself and this is enough to
1614 	 * accomodate us.  In the worst case, a UMA_SMALLEST_UNIT sized
1615 	 * object with offpage slab header would have ipers =
1616 	 * UMA_SLAB_SIZE / UMA_SMALLEST_UNIT (currently = 256), which is
1617 	 * 1 greater than what our byte-integer freelist index can
1618 	 * accomodate, but we know that this situation never occurs as
1619 	 * for UMA_SMALLEST_UNIT-sized objects, we will never calculate
1620 	 * that we need to go to offpage slab headers.  Or, if we do,
1621 	 * then we trap that condition below and panic in the INVARIANTS case.
1622 	 */
1623 	wsize = UMA_SLAB_SIZE - sizeof(struct uma_slab) - UMA_MAX_WASTE;
1624 	totsize = wsize;
1625 	objsize = UMA_SMALLEST_UNIT;
1626 	while (totsize >= wsize) {
1627 		totsize = (UMA_SLAB_SIZE - sizeof(struct uma_slab)) /
1628 		    (objsize + UMA_FRITM_SZ);
1629 		totsize *= (UMA_FRITM_SZ + objsize);
1630 		objsize++;
1631 	}
1632 	if (objsize > UMA_SMALLEST_UNIT)
1633 		objsize--;
1634 	uma_max_ipers = MAX(UMA_SLAB_SIZE / objsize, 64);
1635 
1636 	wsize = UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt) - UMA_MAX_WASTE;
1637 	totsize = wsize;
1638 	objsize = UMA_SMALLEST_UNIT;
1639 	while (totsize >= wsize) {
1640 		totsize = (UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt)) /
1641 		    (objsize + UMA_FRITMREF_SZ);
1642 		totsize *= (UMA_FRITMREF_SZ + objsize);
1643 		objsize++;
1644 	}
1645 	if (objsize > UMA_SMALLEST_UNIT)
1646 		objsize--;
1647 	uma_max_ipers_ref = MAX(UMA_SLAB_SIZE / objsize, 64);
1648 
1649 	KASSERT((uma_max_ipers_ref <= 255) && (uma_max_ipers <= 255),
1650 	    ("uma_startup: calculated uma_max_ipers values too large!"));
1651 
1652 #ifdef UMA_DEBUG
1653 	printf("Calculated uma_max_ipers (for OFFPAGE) is %d\n", uma_max_ipers);
1654 	printf("Calculated uma_max_ipers_slab (for OFFPAGE) is %d\n",
1655 	    uma_max_ipers_ref);
1656 #endif
1657 
1658 	/* "manually" create the initial zone */
1659 	args.name = "UMA Kegs";
1660 	args.size = sizeof(struct uma_keg);
1661 	args.ctor = keg_ctor;
1662 	args.dtor = keg_dtor;
1663 	args.uminit = zero_init;
1664 	args.fini = NULL;
1665 	args.keg = &masterkeg;
1666 	args.align = 32 - 1;
1667 	args.flags = UMA_ZFLAG_INTERNAL;
1668 	/* The initial zone has no Per cpu queues so it's smaller */
1669 	zone_ctor(kegs, sizeof(struct uma_zone), &args, M_WAITOK);
1670 
1671 #ifdef UMA_DEBUG
1672 	printf("Filling boot free list.\n");
1673 #endif
1674 	for (i = 0; i < boot_pages; i++) {
1675 		slab = (uma_slab_t)((u_int8_t *)bootmem + (i * UMA_SLAB_SIZE));
1676 		slab->us_data = (u_int8_t *)slab;
1677 		slab->us_flags = UMA_SLAB_BOOT;
1678 		LIST_INSERT_HEAD(&uma_boot_pages, slab, us_link);
1679 	}
1680 	mtx_init(&uma_boot_pages_mtx, "UMA boot pages", NULL, MTX_DEF);
1681 
1682 #ifdef UMA_DEBUG
1683 	printf("Creating uma zone headers zone and keg.\n");
1684 #endif
1685 	args.name = "UMA Zones";
1686 	args.size = sizeof(struct uma_zone) +
1687 	    (sizeof(struct uma_cache) * (mp_maxid + 1));
1688 	args.ctor = zone_ctor;
1689 	args.dtor = zone_dtor;
1690 	args.uminit = zero_init;
1691 	args.fini = NULL;
1692 	args.keg = NULL;
1693 	args.align = 32 - 1;
1694 	args.flags = UMA_ZFLAG_INTERNAL;
1695 	/* The initial zone has no Per cpu queues so it's smaller */
1696 	zone_ctor(zones, sizeof(struct uma_zone), &args, M_WAITOK);
1697 
1698 #ifdef UMA_DEBUG
1699 	printf("Initializing pcpu cache locks.\n");
1700 #endif
1701 #ifdef UMA_DEBUG
1702 	printf("Creating slab and hash zones.\n");
1703 #endif
1704 
1705 	/*
1706 	 * This is the max number of free list items we'll have with
1707 	 * offpage slabs.
1708 	 */
1709 	slabsize = uma_max_ipers * UMA_FRITM_SZ;
1710 	slabsize += sizeof(struct uma_slab);
1711 
1712 	/* Now make a zone for slab headers */
1713 	slabzone = uma_zcreate("UMA Slabs",
1714 				slabsize,
1715 				NULL, NULL, NULL, NULL,
1716 				UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
1717 
1718 	/*
1719 	 * We also create a zone for the bigger slabs with reference
1720 	 * counts in them, to accomodate UMA_ZONE_REFCNT zones.
1721 	 */
1722 	slabsize = uma_max_ipers_ref * UMA_FRITMREF_SZ;
1723 	slabsize += sizeof(struct uma_slab_refcnt);
1724 	slabrefzone = uma_zcreate("UMA RCntSlabs",
1725 				  slabsize,
1726 				  NULL, NULL, NULL, NULL,
1727 				  UMA_ALIGN_PTR,
1728 				  UMA_ZFLAG_INTERNAL);
1729 
1730 	hashzone = uma_zcreate("UMA Hash",
1731 	    sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT,
1732 	    NULL, NULL, NULL, NULL,
1733 	    UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
1734 
1735 	bucket_init();
1736 
1737 #if defined(UMA_MD_SMALL_ALLOC) && !defined(UMA_MD_SMALL_ALLOC_NEEDS_VM)
1738 	booted = 1;
1739 #endif
1740 
1741 #ifdef UMA_DEBUG
1742 	printf("UMA startup complete.\n");
1743 #endif
1744 }
1745 
1746 /* see uma.h */
1747 void
1748 uma_startup2(void)
1749 {
1750 	booted = 1;
1751 	bucket_enable();
1752 #ifdef UMA_DEBUG
1753 	printf("UMA startup2 complete.\n");
1754 #endif
1755 }
1756 
1757 /*
1758  * Initialize our callout handle
1759  *
1760  */
1761 
1762 static void
1763 uma_startup3(void)
1764 {
1765 #ifdef UMA_DEBUG
1766 	printf("Starting callout.\n");
1767 #endif
1768 	callout_init(&uma_callout, CALLOUT_MPSAFE);
1769 	callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
1770 #ifdef UMA_DEBUG
1771 	printf("UMA startup3 complete.\n");
1772 #endif
1773 }
1774 
1775 static uma_keg_t
1776 uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini,
1777 		int align, u_int32_t flags)
1778 {
1779 	struct uma_kctor_args args;
1780 
1781 	args.size = size;
1782 	args.uminit = uminit;
1783 	args.fini = fini;
1784 	args.align = (align == UMA_ALIGN_CACHE) ? uma_align_cache : align;
1785 	args.flags = flags;
1786 	args.zone = zone;
1787 	return (zone_alloc_item(kegs, &args, M_WAITOK));
1788 }
1789 
1790 /* See uma.h */
1791 void
1792 uma_set_align(int align)
1793 {
1794 
1795 	if (align != UMA_ALIGN_CACHE)
1796 		uma_align_cache = align;
1797 }
1798 
1799 /* See uma.h */
1800 uma_zone_t
1801 uma_zcreate(char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
1802 		uma_init uminit, uma_fini fini, int align, u_int32_t flags)
1803 
1804 {
1805 	struct uma_zctor_args args;
1806 
1807 	/* This stuff is essential for the zone ctor */
1808 	args.name = name;
1809 	args.size = size;
1810 	args.ctor = ctor;
1811 	args.dtor = dtor;
1812 	args.uminit = uminit;
1813 	args.fini = fini;
1814 	args.align = align;
1815 	args.flags = flags;
1816 	args.keg = NULL;
1817 
1818 	return (zone_alloc_item(zones, &args, M_WAITOK));
1819 }
1820 
1821 /* See uma.h */
1822 uma_zone_t
1823 uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
1824 		    uma_init zinit, uma_fini zfini, uma_zone_t master)
1825 {
1826 	struct uma_zctor_args args;
1827 	uma_keg_t keg;
1828 
1829 	keg = zone_first_keg(master);
1830 	args.name = name;
1831 	args.size = keg->uk_size;
1832 	args.ctor = ctor;
1833 	args.dtor = dtor;
1834 	args.uminit = zinit;
1835 	args.fini = zfini;
1836 	args.align = keg->uk_align;
1837 	args.flags = keg->uk_flags | UMA_ZONE_SECONDARY;
1838 	args.keg = keg;
1839 
1840 	/* XXX Attaches only one keg of potentially many. */
1841 	return (zone_alloc_item(zones, &args, M_WAITOK));
1842 }
1843 
1844 static void
1845 zone_lock_pair(uma_zone_t a, uma_zone_t b)
1846 {
1847 	if (a < b) {
1848 		ZONE_LOCK(a);
1849 		mtx_lock_flags(b->uz_lock, MTX_DUPOK);
1850 	} else {
1851 		ZONE_LOCK(b);
1852 		mtx_lock_flags(a->uz_lock, MTX_DUPOK);
1853 	}
1854 }
1855 
1856 static void
1857 zone_unlock_pair(uma_zone_t a, uma_zone_t b)
1858 {
1859 
1860 	ZONE_UNLOCK(a);
1861 	ZONE_UNLOCK(b);
1862 }
1863 
1864 int
1865 uma_zsecond_add(uma_zone_t zone, uma_zone_t master)
1866 {
1867 	uma_klink_t klink;
1868 	uma_klink_t kl;
1869 	int error;
1870 
1871 	error = 0;
1872 	klink = malloc(sizeof(*klink), M_TEMP, M_WAITOK | M_ZERO);
1873 
1874 	zone_lock_pair(zone, master);
1875 	/*
1876 	 * zone must use vtoslab() to resolve objects and must already be
1877 	 * a secondary.
1878 	 */
1879 	if ((zone->uz_flags & (UMA_ZONE_VTOSLAB | UMA_ZONE_SECONDARY))
1880 	    != (UMA_ZONE_VTOSLAB | UMA_ZONE_SECONDARY)) {
1881 		error = EINVAL;
1882 		goto out;
1883 	}
1884 	/*
1885 	 * The new master must also use vtoslab().
1886 	 */
1887 	if ((zone->uz_flags & UMA_ZONE_VTOSLAB) != UMA_ZONE_VTOSLAB) {
1888 		error = EINVAL;
1889 		goto out;
1890 	}
1891 	/*
1892 	 * Both must either be refcnt, or not be refcnt.
1893 	 */
1894 	if ((zone->uz_flags & UMA_ZONE_REFCNT) !=
1895 	    (master->uz_flags & UMA_ZONE_REFCNT)) {
1896 		error = EINVAL;
1897 		goto out;
1898 	}
1899 	/*
1900 	 * The underlying object must be the same size.  rsize
1901 	 * may be different.
1902 	 */
1903 	if (master->uz_size != zone->uz_size) {
1904 		error = E2BIG;
1905 		goto out;
1906 	}
1907 	/*
1908 	 * Put it at the end of the list.
1909 	 */
1910 	klink->kl_keg = zone_first_keg(master);
1911 	LIST_FOREACH(kl, &zone->uz_kegs, kl_link) {
1912 		if (LIST_NEXT(kl, kl_link) == NULL) {
1913 			LIST_INSERT_AFTER(kl, klink, kl_link);
1914 			break;
1915 		}
1916 	}
1917 	klink = NULL;
1918 	zone->uz_flags |= UMA_ZFLAG_MULTI;
1919 	zone->uz_slab = zone_fetch_slab_multi;
1920 
1921 out:
1922 	zone_unlock_pair(zone, master);
1923 	if (klink != NULL)
1924 		free(klink, M_TEMP);
1925 
1926 	return (error);
1927 }
1928 
1929 
1930 /* See uma.h */
1931 void
1932 uma_zdestroy(uma_zone_t zone)
1933 {
1934 
1935 	zone_free_item(zones, zone, NULL, SKIP_NONE, ZFREE_STATFREE);
1936 }
1937 
1938 /* See uma.h */
1939 void *
1940 uma_zalloc_arg(uma_zone_t zone, void *udata, int flags)
1941 {
1942 	void *item;
1943 	uma_cache_t cache;
1944 	uma_bucket_t bucket;
1945 	int cpu;
1946 
1947 	/* This is the fast path allocation */
1948 #ifdef UMA_DEBUG_ALLOC_1
1949 	printf("Allocating one item from %s(%p)\n", zone->uz_name, zone);
1950 #endif
1951 	CTR3(KTR_UMA, "uma_zalloc_arg thread %x zone %s flags %d", curthread,
1952 	    zone->uz_name, flags);
1953 
1954 	if (flags & M_WAITOK) {
1955 		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
1956 		    "uma_zalloc_arg: zone \"%s\"", zone->uz_name);
1957 	}
1958 
1959 	/*
1960 	 * If possible, allocate from the per-CPU cache.  There are two
1961 	 * requirements for safe access to the per-CPU cache: (1) the thread
1962 	 * accessing the cache must not be preempted or yield during access,
1963 	 * and (2) the thread must not migrate CPUs without switching which
1964 	 * cache it accesses.  We rely on a critical section to prevent
1965 	 * preemption and migration.  We release the critical section in
1966 	 * order to acquire the zone mutex if we are unable to allocate from
1967 	 * the current cache; when we re-acquire the critical section, we
1968 	 * must detect and handle migration if it has occurred.
1969 	 */
1970 zalloc_restart:
1971 	critical_enter();
1972 	cpu = curcpu;
1973 	cache = &zone->uz_cpu[cpu];
1974 
1975 zalloc_start:
1976 	bucket = cache->uc_allocbucket;
1977 
1978 	if (bucket) {
1979 		if (bucket->ub_cnt > 0) {
1980 			bucket->ub_cnt--;
1981 			item = bucket->ub_bucket[bucket->ub_cnt];
1982 #ifdef INVARIANTS
1983 			bucket->ub_bucket[bucket->ub_cnt] = NULL;
1984 #endif
1985 			KASSERT(item != NULL,
1986 			    ("uma_zalloc: Bucket pointer mangled."));
1987 			cache->uc_allocs++;
1988 			critical_exit();
1989 #ifdef INVARIANTS
1990 			ZONE_LOCK(zone);
1991 			uma_dbg_alloc(zone, NULL, item);
1992 			ZONE_UNLOCK(zone);
1993 #endif
1994 			if (zone->uz_ctor != NULL) {
1995 				if (zone->uz_ctor(item, zone->uz_size,
1996 				    udata, flags) != 0) {
1997 					zone_free_item(zone, item, udata,
1998 					    SKIP_DTOR, ZFREE_STATFAIL |
1999 					    ZFREE_STATFREE);
2000 					return (NULL);
2001 				}
2002 			}
2003 			if (flags & M_ZERO)
2004 				bzero(item, zone->uz_size);
2005 			return (item);
2006 		} else if (cache->uc_freebucket) {
2007 			/*
2008 			 * We have run out of items in our allocbucket.
2009 			 * See if we can switch with our free bucket.
2010 			 */
2011 			if (cache->uc_freebucket->ub_cnt > 0) {
2012 #ifdef UMA_DEBUG_ALLOC
2013 				printf("uma_zalloc: Swapping empty with"
2014 				    " alloc.\n");
2015 #endif
2016 				bucket = cache->uc_freebucket;
2017 				cache->uc_freebucket = cache->uc_allocbucket;
2018 				cache->uc_allocbucket = bucket;
2019 
2020 				goto zalloc_start;
2021 			}
2022 		}
2023 	}
2024 	/*
2025 	 * Attempt to retrieve the item from the per-CPU cache has failed, so
2026 	 * we must go back to the zone.  This requires the zone lock, so we
2027 	 * must drop the critical section, then re-acquire it when we go back
2028 	 * to the cache.  Since the critical section is released, we may be
2029 	 * preempted or migrate.  As such, make sure not to maintain any
2030 	 * thread-local state specific to the cache from prior to releasing
2031 	 * the critical section.
2032 	 */
2033 	critical_exit();
2034 	ZONE_LOCK(zone);
2035 	critical_enter();
2036 	cpu = curcpu;
2037 	cache = &zone->uz_cpu[cpu];
2038 	bucket = cache->uc_allocbucket;
2039 	if (bucket != NULL) {
2040 		if (bucket->ub_cnt > 0) {
2041 			ZONE_UNLOCK(zone);
2042 			goto zalloc_start;
2043 		}
2044 		bucket = cache->uc_freebucket;
2045 		if (bucket != NULL && bucket->ub_cnt > 0) {
2046 			ZONE_UNLOCK(zone);
2047 			goto zalloc_start;
2048 		}
2049 	}
2050 
2051 	/* Since we have locked the zone we may as well send back our stats */
2052 	zone->uz_allocs += cache->uc_allocs;
2053 	cache->uc_allocs = 0;
2054 	zone->uz_frees += cache->uc_frees;
2055 	cache->uc_frees = 0;
2056 
2057 	/* Our old one is now a free bucket */
2058 	if (cache->uc_allocbucket) {
2059 		KASSERT(cache->uc_allocbucket->ub_cnt == 0,
2060 		    ("uma_zalloc_arg: Freeing a non free bucket."));
2061 		LIST_INSERT_HEAD(&zone->uz_free_bucket,
2062 		    cache->uc_allocbucket, ub_link);
2063 		cache->uc_allocbucket = NULL;
2064 	}
2065 
2066 	/* Check the free list for a new alloc bucket */
2067 	if ((bucket = LIST_FIRST(&zone->uz_full_bucket)) != NULL) {
2068 		KASSERT(bucket->ub_cnt != 0,
2069 		    ("uma_zalloc_arg: Returning an empty bucket."));
2070 
2071 		LIST_REMOVE(bucket, ub_link);
2072 		cache->uc_allocbucket = bucket;
2073 		ZONE_UNLOCK(zone);
2074 		goto zalloc_start;
2075 	}
2076 	/* We are no longer associated with this CPU. */
2077 	critical_exit();
2078 
2079 	/* Bump up our uz_count so we get here less */
2080 	if (zone->uz_count < BUCKET_MAX)
2081 		zone->uz_count++;
2082 
2083 	/*
2084 	 * Now lets just fill a bucket and put it on the free list.  If that
2085 	 * works we'll restart the allocation from the begining.
2086 	 */
2087 	if (zone_alloc_bucket(zone, flags)) {
2088 		ZONE_UNLOCK(zone);
2089 		goto zalloc_restart;
2090 	}
2091 	ZONE_UNLOCK(zone);
2092 	/*
2093 	 * We may not be able to get a bucket so return an actual item.
2094 	 */
2095 #ifdef UMA_DEBUG
2096 	printf("uma_zalloc_arg: Bucketzone returned NULL\n");
2097 #endif
2098 
2099 	item = zone_alloc_item(zone, udata, flags);
2100 	return (item);
2101 }
2102 
2103 static uma_slab_t
2104 keg_fetch_slab(uma_keg_t keg, uma_zone_t zone, int flags)
2105 {
2106 	uma_slab_t slab;
2107 
2108 	mtx_assert(&keg->uk_lock, MA_OWNED);
2109 	slab = NULL;
2110 
2111 	for (;;) {
2112 		/*
2113 		 * Find a slab with some space.  Prefer slabs that are partially
2114 		 * used over those that are totally full.  This helps to reduce
2115 		 * fragmentation.
2116 		 */
2117 		if (keg->uk_free != 0) {
2118 			if (!LIST_EMPTY(&keg->uk_part_slab)) {
2119 				slab = LIST_FIRST(&keg->uk_part_slab);
2120 			} else {
2121 				slab = LIST_FIRST(&keg->uk_free_slab);
2122 				LIST_REMOVE(slab, us_link);
2123 				LIST_INSERT_HEAD(&keg->uk_part_slab, slab,
2124 				    us_link);
2125 			}
2126 			MPASS(slab->us_keg == keg);
2127 			return (slab);
2128 		}
2129 
2130 		/*
2131 		 * M_NOVM means don't ask at all!
2132 		 */
2133 		if (flags & M_NOVM)
2134 			break;
2135 
2136 		if (keg->uk_maxpages && keg->uk_pages >= keg->uk_maxpages) {
2137 			keg->uk_flags |= UMA_ZFLAG_FULL;
2138 			/*
2139 			 * If this is not a multi-zone, set the FULL bit.
2140 			 * Otherwise slab_multi() takes care of it.
2141 			 */
2142 			if ((zone->uz_flags & UMA_ZFLAG_MULTI) == 0)
2143 				zone->uz_flags |= UMA_ZFLAG_FULL;
2144 			if (flags & M_NOWAIT)
2145 				break;
2146 			msleep(keg, &keg->uk_lock, PVM, "keglimit", 0);
2147 			continue;
2148 		}
2149 		keg->uk_recurse++;
2150 		slab = keg_alloc_slab(keg, zone, flags);
2151 		keg->uk_recurse--;
2152 		/*
2153 		 * If we got a slab here it's safe to mark it partially used
2154 		 * and return.  We assume that the caller is going to remove
2155 		 * at least one item.
2156 		 */
2157 		if (slab) {
2158 			MPASS(slab->us_keg == keg);
2159 			LIST_INSERT_HEAD(&keg->uk_part_slab, slab, us_link);
2160 			return (slab);
2161 		}
2162 		/*
2163 		 * We might not have been able to get a slab but another cpu
2164 		 * could have while we were unlocked.  Check again before we
2165 		 * fail.
2166 		 */
2167 		flags |= M_NOVM;
2168 	}
2169 	return (slab);
2170 }
2171 
2172 static inline void
2173 zone_relock(uma_zone_t zone, uma_keg_t keg)
2174 {
2175 	if (zone->uz_lock != &keg->uk_lock) {
2176 		KEG_UNLOCK(keg);
2177 		ZONE_LOCK(zone);
2178 	}
2179 }
2180 
2181 static inline void
2182 keg_relock(uma_keg_t keg, uma_zone_t zone)
2183 {
2184 	if (zone->uz_lock != &keg->uk_lock) {
2185 		ZONE_UNLOCK(zone);
2186 		KEG_LOCK(keg);
2187 	}
2188 }
2189 
2190 static uma_slab_t
2191 zone_fetch_slab(uma_zone_t zone, uma_keg_t keg, int flags)
2192 {
2193 	uma_slab_t slab;
2194 
2195 	if (keg == NULL)
2196 		keg = zone_first_keg(zone);
2197 	/*
2198 	 * This is to prevent us from recursively trying to allocate
2199 	 * buckets.  The problem is that if an allocation forces us to
2200 	 * grab a new bucket we will call page_alloc, which will go off
2201 	 * and cause the vm to allocate vm_map_entries.  If we need new
2202 	 * buckets there too we will recurse in kmem_alloc and bad
2203 	 * things happen.  So instead we return a NULL bucket, and make
2204 	 * the code that allocates buckets smart enough to deal with it
2205 	 */
2206 	if (keg->uk_flags & UMA_ZFLAG_BUCKET && keg->uk_recurse != 0)
2207 		return (NULL);
2208 
2209 	for (;;) {
2210 		slab = keg_fetch_slab(keg, zone, flags);
2211 		if (slab)
2212 			return (slab);
2213 		if (flags & (M_NOWAIT | M_NOVM))
2214 			break;
2215 	}
2216 	return (NULL);
2217 }
2218 
2219 /*
2220  * uma_zone_fetch_slab_multi:  Fetches a slab from one available keg.  Returns
2221  * with the keg locked.  Caller must call zone_relock() afterwards if the
2222  * zone lock is required.  On NULL the zone lock is held.
2223  *
2224  * The last pointer is used to seed the search.  It is not required.
2225  */
2226 static uma_slab_t
2227 zone_fetch_slab_multi(uma_zone_t zone, uma_keg_t last, int rflags)
2228 {
2229 	uma_klink_t klink;
2230 	uma_slab_t slab;
2231 	uma_keg_t keg;
2232 	int flags;
2233 	int empty;
2234 	int full;
2235 
2236 	/*
2237 	 * Don't wait on the first pass.  This will skip limit tests
2238 	 * as well.  We don't want to block if we can find a provider
2239 	 * without blocking.
2240 	 */
2241 	flags = (rflags & ~M_WAITOK) | M_NOWAIT;
2242 	/*
2243 	 * Use the last slab allocated as a hint for where to start
2244 	 * the search.
2245 	 */
2246 	if (last) {
2247 		slab = keg_fetch_slab(last, zone, flags);
2248 		if (slab)
2249 			return (slab);
2250 		zone_relock(zone, last);
2251 		last = NULL;
2252 	}
2253 	/*
2254 	 * Loop until we have a slab incase of transient failures
2255 	 * while M_WAITOK is specified.  I'm not sure this is 100%
2256 	 * required but we've done it for so long now.
2257 	 */
2258 	for (;;) {
2259 		empty = 0;
2260 		full = 0;
2261 		/*
2262 		 * Search the available kegs for slabs.  Be careful to hold the
2263 		 * correct lock while calling into the keg layer.
2264 		 */
2265 		LIST_FOREACH(klink, &zone->uz_kegs, kl_link) {
2266 			keg = klink->kl_keg;
2267 			keg_relock(keg, zone);
2268 			if ((keg->uk_flags & UMA_ZFLAG_FULL) == 0) {
2269 				slab = keg_fetch_slab(keg, zone, flags);
2270 				if (slab)
2271 					return (slab);
2272 			}
2273 			if (keg->uk_flags & UMA_ZFLAG_FULL)
2274 				full++;
2275 			else
2276 				empty++;
2277 			zone_relock(zone, keg);
2278 		}
2279 		if (rflags & (M_NOWAIT | M_NOVM))
2280 			break;
2281 		flags = rflags;
2282 		/*
2283 		 * All kegs are full.  XXX We can't atomically check all kegs
2284 		 * and sleep so just sleep for a short period and retry.
2285 		 */
2286 		if (full && !empty) {
2287 			zone->uz_flags |= UMA_ZFLAG_FULL;
2288 			msleep(zone, zone->uz_lock, PVM, "zonelimit", hz/100);
2289 			zone->uz_flags &= ~UMA_ZFLAG_FULL;
2290 			continue;
2291 		}
2292 	}
2293 	return (NULL);
2294 }
2295 
2296 static void *
2297 slab_alloc_item(uma_zone_t zone, uma_slab_t slab)
2298 {
2299 	uma_keg_t keg;
2300 	uma_slabrefcnt_t slabref;
2301 	void *item;
2302 	u_int8_t freei;
2303 
2304 	keg = slab->us_keg;
2305 	mtx_assert(&keg->uk_lock, MA_OWNED);
2306 
2307 	freei = slab->us_firstfree;
2308 	if (keg->uk_flags & UMA_ZONE_REFCNT) {
2309 		slabref = (uma_slabrefcnt_t)slab;
2310 		slab->us_firstfree = slabref->us_freelist[freei].us_item;
2311 	} else {
2312 		slab->us_firstfree = slab->us_freelist[freei].us_item;
2313 	}
2314 	item = slab->us_data + (keg->uk_rsize * freei);
2315 
2316 	slab->us_freecount--;
2317 	keg->uk_free--;
2318 #ifdef INVARIANTS
2319 	uma_dbg_alloc(zone, slab, item);
2320 #endif
2321 	/* Move this slab to the full list */
2322 	if (slab->us_freecount == 0) {
2323 		LIST_REMOVE(slab, us_link);
2324 		LIST_INSERT_HEAD(&keg->uk_full_slab, slab, us_link);
2325 	}
2326 
2327 	return (item);
2328 }
2329 
2330 static int
2331 zone_alloc_bucket(uma_zone_t zone, int flags)
2332 {
2333 	uma_bucket_t bucket;
2334 	uma_slab_t slab;
2335 	uma_keg_t keg;
2336 	int16_t saved;
2337 	int max, origflags = flags;
2338 
2339 	/*
2340 	 * Try this zone's free list first so we don't allocate extra buckets.
2341 	 */
2342 	if ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) {
2343 		KASSERT(bucket->ub_cnt == 0,
2344 		    ("zone_alloc_bucket: Bucket on free list is not empty."));
2345 		LIST_REMOVE(bucket, ub_link);
2346 	} else {
2347 		int bflags;
2348 
2349 		bflags = (flags & ~M_ZERO);
2350 		if (zone->uz_flags & UMA_ZFLAG_CACHEONLY)
2351 			bflags |= M_NOVM;
2352 
2353 		ZONE_UNLOCK(zone);
2354 		bucket = bucket_alloc(zone->uz_count, bflags);
2355 		ZONE_LOCK(zone);
2356 	}
2357 
2358 	if (bucket == NULL) {
2359 		return (0);
2360 	}
2361 
2362 #ifdef SMP
2363 	/*
2364 	 * This code is here to limit the number of simultaneous bucket fills
2365 	 * for any given zone to the number of per cpu caches in this zone. This
2366 	 * is done so that we don't allocate more memory than we really need.
2367 	 */
2368 	if (zone->uz_fills >= mp_ncpus)
2369 		goto done;
2370 
2371 #endif
2372 	zone->uz_fills++;
2373 
2374 	max = MIN(bucket->ub_entries, zone->uz_count);
2375 	/* Try to keep the buckets totally full */
2376 	saved = bucket->ub_cnt;
2377 	slab = NULL;
2378 	keg = NULL;
2379 	while (bucket->ub_cnt < max &&
2380 	    (slab = zone->uz_slab(zone, keg, flags)) != NULL) {
2381 		keg = slab->us_keg;
2382 		while (slab->us_freecount && bucket->ub_cnt < max) {
2383 			bucket->ub_bucket[bucket->ub_cnt++] =
2384 			    slab_alloc_item(zone, slab);
2385 		}
2386 
2387 		/* Don't block on the next fill */
2388 		flags |= M_NOWAIT;
2389 	}
2390 	if (slab)
2391 		zone_relock(zone, keg);
2392 
2393 	/*
2394 	 * We unlock here because we need to call the zone's init.
2395 	 * It should be safe to unlock because the slab dealt with
2396 	 * above is already on the appropriate list within the keg
2397 	 * and the bucket we filled is not yet on any list, so we
2398 	 * own it.
2399 	 */
2400 	if (zone->uz_init != NULL) {
2401 		int i;
2402 
2403 		ZONE_UNLOCK(zone);
2404 		for (i = saved; i < bucket->ub_cnt; i++)
2405 			if (zone->uz_init(bucket->ub_bucket[i], zone->uz_size,
2406 			    origflags) != 0)
2407 				break;
2408 		/*
2409 		 * If we couldn't initialize the whole bucket, put the
2410 		 * rest back onto the freelist.
2411 		 */
2412 		if (i != bucket->ub_cnt) {
2413 			int j;
2414 
2415 			for (j = i; j < bucket->ub_cnt; j++) {
2416 				zone_free_item(zone, bucket->ub_bucket[j],
2417 				    NULL, SKIP_FINI, 0);
2418 #ifdef INVARIANTS
2419 				bucket->ub_bucket[j] = NULL;
2420 #endif
2421 			}
2422 			bucket->ub_cnt = i;
2423 		}
2424 		ZONE_LOCK(zone);
2425 	}
2426 
2427 	zone->uz_fills--;
2428 	if (bucket->ub_cnt != 0) {
2429 		LIST_INSERT_HEAD(&zone->uz_full_bucket,
2430 		    bucket, ub_link);
2431 		return (1);
2432 	}
2433 #ifdef SMP
2434 done:
2435 #endif
2436 	bucket_free(bucket);
2437 
2438 	return (0);
2439 }
2440 /*
2441  * Allocates an item for an internal zone
2442  *
2443  * Arguments
2444  *	zone   The zone to alloc for.
2445  *	udata  The data to be passed to the constructor.
2446  *	flags  M_WAITOK, M_NOWAIT, M_ZERO.
2447  *
2448  * Returns
2449  *	NULL if there is no memory and M_NOWAIT is set
2450  *	An item if successful
2451  */
2452 
2453 static void *
2454 zone_alloc_item(uma_zone_t zone, void *udata, int flags)
2455 {
2456 	uma_slab_t slab;
2457 	void *item;
2458 
2459 	item = NULL;
2460 
2461 #ifdef UMA_DEBUG_ALLOC
2462 	printf("INTERNAL: Allocating one item from %s(%p)\n", zone->uz_name, zone);
2463 #endif
2464 	ZONE_LOCK(zone);
2465 
2466 	slab = zone->uz_slab(zone, NULL, flags);
2467 	if (slab == NULL) {
2468 		zone->uz_fails++;
2469 		ZONE_UNLOCK(zone);
2470 		return (NULL);
2471 	}
2472 
2473 	item = slab_alloc_item(zone, slab);
2474 
2475 	zone_relock(zone, slab->us_keg);
2476 	zone->uz_allocs++;
2477 	ZONE_UNLOCK(zone);
2478 
2479 	/*
2480 	 * We have to call both the zone's init (not the keg's init)
2481 	 * and the zone's ctor.  This is because the item is going from
2482 	 * a keg slab directly to the user, and the user is expecting it
2483 	 * to be both zone-init'd as well as zone-ctor'd.
2484 	 */
2485 	if (zone->uz_init != NULL) {
2486 		if (zone->uz_init(item, zone->uz_size, flags) != 0) {
2487 			zone_free_item(zone, item, udata, SKIP_FINI,
2488 			    ZFREE_STATFAIL | ZFREE_STATFREE);
2489 			return (NULL);
2490 		}
2491 	}
2492 	if (zone->uz_ctor != NULL) {
2493 		if (zone->uz_ctor(item, zone->uz_size, udata, flags) != 0) {
2494 			zone_free_item(zone, item, udata, SKIP_DTOR,
2495 			    ZFREE_STATFAIL | ZFREE_STATFREE);
2496 			return (NULL);
2497 		}
2498 	}
2499 	if (flags & M_ZERO)
2500 		bzero(item, zone->uz_size);
2501 
2502 	return (item);
2503 }
2504 
2505 /* See uma.h */
2506 void
2507 uma_zfree_arg(uma_zone_t zone, void *item, void *udata)
2508 {
2509 	uma_cache_t cache;
2510 	uma_bucket_t bucket;
2511 	int bflags;
2512 	int cpu;
2513 
2514 #ifdef UMA_DEBUG_ALLOC_1
2515 	printf("Freeing item %p to %s(%p)\n", item, zone->uz_name, zone);
2516 #endif
2517 	CTR2(KTR_UMA, "uma_zfree_arg thread %x zone %s", curthread,
2518 	    zone->uz_name);
2519 
2520 	if (zone->uz_dtor)
2521 		zone->uz_dtor(item, zone->uz_size, udata);
2522 
2523 #ifdef INVARIANTS
2524 	ZONE_LOCK(zone);
2525 	if (zone->uz_flags & UMA_ZONE_MALLOC)
2526 		uma_dbg_free(zone, udata, item);
2527 	else
2528 		uma_dbg_free(zone, NULL, item);
2529 	ZONE_UNLOCK(zone);
2530 #endif
2531 	/*
2532 	 * The race here is acceptable.  If we miss it we'll just have to wait
2533 	 * a little longer for the limits to be reset.
2534 	 */
2535 	if (zone->uz_flags & UMA_ZFLAG_FULL)
2536 		goto zfree_internal;
2537 
2538 	/*
2539 	 * If possible, free to the per-CPU cache.  There are two
2540 	 * requirements for safe access to the per-CPU cache: (1) the thread
2541 	 * accessing the cache must not be preempted or yield during access,
2542 	 * and (2) the thread must not migrate CPUs without switching which
2543 	 * cache it accesses.  We rely on a critical section to prevent
2544 	 * preemption and migration.  We release the critical section in
2545 	 * order to acquire the zone mutex if we are unable to free to the
2546 	 * current cache; when we re-acquire the critical section, we must
2547 	 * detect and handle migration if it has occurred.
2548 	 */
2549 zfree_restart:
2550 	critical_enter();
2551 	cpu = curcpu;
2552 	cache = &zone->uz_cpu[cpu];
2553 
2554 zfree_start:
2555 	bucket = cache->uc_freebucket;
2556 
2557 	if (bucket) {
2558 		/*
2559 		 * Do we have room in our bucket? It is OK for this uz count
2560 		 * check to be slightly out of sync.
2561 		 */
2562 
2563 		if (bucket->ub_cnt < bucket->ub_entries) {
2564 			KASSERT(bucket->ub_bucket[bucket->ub_cnt] == NULL,
2565 			    ("uma_zfree: Freeing to non free bucket index."));
2566 			bucket->ub_bucket[bucket->ub_cnt] = item;
2567 			bucket->ub_cnt++;
2568 			cache->uc_frees++;
2569 			critical_exit();
2570 			return;
2571 		} else if (cache->uc_allocbucket) {
2572 #ifdef UMA_DEBUG_ALLOC
2573 			printf("uma_zfree: Swapping buckets.\n");
2574 #endif
2575 			/*
2576 			 * We have run out of space in our freebucket.
2577 			 * See if we can switch with our alloc bucket.
2578 			 */
2579 			if (cache->uc_allocbucket->ub_cnt <
2580 			    cache->uc_freebucket->ub_cnt) {
2581 				bucket = cache->uc_freebucket;
2582 				cache->uc_freebucket = cache->uc_allocbucket;
2583 				cache->uc_allocbucket = bucket;
2584 				goto zfree_start;
2585 			}
2586 		}
2587 	}
2588 	/*
2589 	 * We can get here for two reasons:
2590 	 *
2591 	 * 1) The buckets are NULL
2592 	 * 2) The alloc and free buckets are both somewhat full.
2593 	 *
2594 	 * We must go back the zone, which requires acquiring the zone lock,
2595 	 * which in turn means we must release and re-acquire the critical
2596 	 * section.  Since the critical section is released, we may be
2597 	 * preempted or migrate.  As such, make sure not to maintain any
2598 	 * thread-local state specific to the cache from prior to releasing
2599 	 * the critical section.
2600 	 */
2601 	critical_exit();
2602 	ZONE_LOCK(zone);
2603 	critical_enter();
2604 	cpu = curcpu;
2605 	cache = &zone->uz_cpu[cpu];
2606 	if (cache->uc_freebucket != NULL) {
2607 		if (cache->uc_freebucket->ub_cnt <
2608 		    cache->uc_freebucket->ub_entries) {
2609 			ZONE_UNLOCK(zone);
2610 			goto zfree_start;
2611 		}
2612 		if (cache->uc_allocbucket != NULL &&
2613 		    (cache->uc_allocbucket->ub_cnt <
2614 		    cache->uc_freebucket->ub_cnt)) {
2615 			ZONE_UNLOCK(zone);
2616 			goto zfree_start;
2617 		}
2618 	}
2619 
2620 	/* Since we have locked the zone we may as well send back our stats */
2621 	zone->uz_allocs += cache->uc_allocs;
2622 	cache->uc_allocs = 0;
2623 	zone->uz_frees += cache->uc_frees;
2624 	cache->uc_frees = 0;
2625 
2626 	bucket = cache->uc_freebucket;
2627 	cache->uc_freebucket = NULL;
2628 
2629 	/* Can we throw this on the zone full list? */
2630 	if (bucket != NULL) {
2631 #ifdef UMA_DEBUG_ALLOC
2632 		printf("uma_zfree: Putting old bucket on the free list.\n");
2633 #endif
2634 		/* ub_cnt is pointing to the last free item */
2635 		KASSERT(bucket->ub_cnt != 0,
2636 		    ("uma_zfree: Attempting to insert an empty bucket onto the full list.\n"));
2637 		LIST_INSERT_HEAD(&zone->uz_full_bucket,
2638 		    bucket, ub_link);
2639 	}
2640 	if ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) {
2641 		LIST_REMOVE(bucket, ub_link);
2642 		ZONE_UNLOCK(zone);
2643 		cache->uc_freebucket = bucket;
2644 		goto zfree_start;
2645 	}
2646 	/* We are no longer associated with this CPU. */
2647 	critical_exit();
2648 
2649 	/* And the zone.. */
2650 	ZONE_UNLOCK(zone);
2651 
2652 #ifdef UMA_DEBUG_ALLOC
2653 	printf("uma_zfree: Allocating new free bucket.\n");
2654 #endif
2655 	bflags = M_NOWAIT;
2656 
2657 	if (zone->uz_flags & UMA_ZFLAG_CACHEONLY)
2658 		bflags |= M_NOVM;
2659 	bucket = bucket_alloc(zone->uz_count, bflags);
2660 	if (bucket) {
2661 		ZONE_LOCK(zone);
2662 		LIST_INSERT_HEAD(&zone->uz_free_bucket,
2663 		    bucket, ub_link);
2664 		ZONE_UNLOCK(zone);
2665 		goto zfree_restart;
2666 	}
2667 
2668 	/*
2669 	 * If nothing else caught this, we'll just do an internal free.
2670 	 */
2671 zfree_internal:
2672 	zone_free_item(zone, item, udata, SKIP_DTOR, ZFREE_STATFREE);
2673 
2674 	return;
2675 }
2676 
2677 /*
2678  * Frees an item to an INTERNAL zone or allocates a free bucket
2679  *
2680  * Arguments:
2681  *	zone   The zone to free to
2682  *	item   The item we're freeing
2683  *	udata  User supplied data for the dtor
2684  *	skip   Skip dtors and finis
2685  */
2686 static void
2687 zone_free_item(uma_zone_t zone, void *item, void *udata,
2688     enum zfreeskip skip, int flags)
2689 {
2690 	uma_slab_t slab;
2691 	uma_slabrefcnt_t slabref;
2692 	uma_keg_t keg;
2693 	u_int8_t *mem;
2694 	u_int8_t freei;
2695 	int clearfull;
2696 
2697 	if (skip < SKIP_DTOR && zone->uz_dtor)
2698 		zone->uz_dtor(item, zone->uz_size, udata);
2699 
2700 	if (skip < SKIP_FINI && zone->uz_fini)
2701 		zone->uz_fini(item, zone->uz_size);
2702 
2703 	ZONE_LOCK(zone);
2704 
2705 	if (flags & ZFREE_STATFAIL)
2706 		zone->uz_fails++;
2707 	if (flags & ZFREE_STATFREE)
2708 		zone->uz_frees++;
2709 
2710 	if (!(zone->uz_flags & UMA_ZONE_VTOSLAB)) {
2711 		mem = (u_int8_t *)((unsigned long)item & (~UMA_SLAB_MASK));
2712 		keg = zone_first_keg(zone); /* Must only be one. */
2713 		if (zone->uz_flags & UMA_ZONE_HASH) {
2714 			slab = hash_sfind(&keg->uk_hash, mem);
2715 		} else {
2716 			mem += keg->uk_pgoff;
2717 			slab = (uma_slab_t)mem;
2718 		}
2719 	} else {
2720 		/* This prevents redundant lookups via free(). */
2721 		if ((zone->uz_flags & UMA_ZONE_MALLOC) && udata != NULL)
2722 			slab = (uma_slab_t)udata;
2723 		else
2724 			slab = vtoslab((vm_offset_t)item);
2725 		keg = slab->us_keg;
2726 		keg_relock(keg, zone);
2727 	}
2728 	MPASS(keg == slab->us_keg);
2729 
2730 	/* Do we need to remove from any lists? */
2731 	if (slab->us_freecount+1 == keg->uk_ipers) {
2732 		LIST_REMOVE(slab, us_link);
2733 		LIST_INSERT_HEAD(&keg->uk_free_slab, slab, us_link);
2734 	} else if (slab->us_freecount == 0) {
2735 		LIST_REMOVE(slab, us_link);
2736 		LIST_INSERT_HEAD(&keg->uk_part_slab, slab, us_link);
2737 	}
2738 
2739 	/* Slab management stuff */
2740 	freei = ((unsigned long)item - (unsigned long)slab->us_data)
2741 		/ keg->uk_rsize;
2742 
2743 #ifdef INVARIANTS
2744 	if (!skip)
2745 		uma_dbg_free(zone, slab, item);
2746 #endif
2747 
2748 	if (keg->uk_flags & UMA_ZONE_REFCNT) {
2749 		slabref = (uma_slabrefcnt_t)slab;
2750 		slabref->us_freelist[freei].us_item = slab->us_firstfree;
2751 	} else {
2752 		slab->us_freelist[freei].us_item = slab->us_firstfree;
2753 	}
2754 	slab->us_firstfree = freei;
2755 	slab->us_freecount++;
2756 
2757 	/* Zone statistics */
2758 	keg->uk_free++;
2759 
2760 	clearfull = 0;
2761 	if (keg->uk_flags & UMA_ZFLAG_FULL) {
2762 		if (keg->uk_pages < keg->uk_maxpages) {
2763 			keg->uk_flags &= ~UMA_ZFLAG_FULL;
2764 			clearfull = 1;
2765 		}
2766 
2767 		/*
2768 		 * We can handle one more allocation. Since we're clearing ZFLAG_FULL,
2769 		 * wake up all procs blocked on pages. This should be uncommon, so
2770 		 * keeping this simple for now (rather than adding count of blocked
2771 		 * threads etc).
2772 		 */
2773 		wakeup(keg);
2774 	}
2775 	if (clearfull) {
2776 		zone_relock(zone, keg);
2777 		zone->uz_flags &= ~UMA_ZFLAG_FULL;
2778 		wakeup(zone);
2779 		ZONE_UNLOCK(zone);
2780 	} else
2781 		KEG_UNLOCK(keg);
2782 }
2783 
2784 /* See uma.h */
2785 void
2786 uma_zone_set_max(uma_zone_t zone, int nitems)
2787 {
2788 	uma_keg_t keg;
2789 
2790 	ZONE_LOCK(zone);
2791 	keg = zone_first_keg(zone);
2792 	keg->uk_maxpages = (nitems / keg->uk_ipers) * keg->uk_ppera;
2793 	if (keg->uk_maxpages * keg->uk_ipers < nitems)
2794 		keg->uk_maxpages += keg->uk_ppera;
2795 
2796 	ZONE_UNLOCK(zone);
2797 }
2798 
2799 /* See uma.h */
2800 void
2801 uma_zone_set_init(uma_zone_t zone, uma_init uminit)
2802 {
2803 	uma_keg_t keg;
2804 
2805 	ZONE_LOCK(zone);
2806 	keg = zone_first_keg(zone);
2807 	KASSERT(keg->uk_pages == 0,
2808 	    ("uma_zone_set_init on non-empty keg"));
2809 	keg->uk_init = uminit;
2810 	ZONE_UNLOCK(zone);
2811 }
2812 
2813 /* See uma.h */
2814 void
2815 uma_zone_set_fini(uma_zone_t zone, uma_fini fini)
2816 {
2817 	uma_keg_t keg;
2818 
2819 	ZONE_LOCK(zone);
2820 	keg = zone_first_keg(zone);
2821 	KASSERT(keg->uk_pages == 0,
2822 	    ("uma_zone_set_fini on non-empty keg"));
2823 	keg->uk_fini = fini;
2824 	ZONE_UNLOCK(zone);
2825 }
2826 
2827 /* See uma.h */
2828 void
2829 uma_zone_set_zinit(uma_zone_t zone, uma_init zinit)
2830 {
2831 	ZONE_LOCK(zone);
2832 	KASSERT(zone_first_keg(zone)->uk_pages == 0,
2833 	    ("uma_zone_set_zinit on non-empty keg"));
2834 	zone->uz_init = zinit;
2835 	ZONE_UNLOCK(zone);
2836 }
2837 
2838 /* See uma.h */
2839 void
2840 uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini)
2841 {
2842 	ZONE_LOCK(zone);
2843 	KASSERT(zone_first_keg(zone)->uk_pages == 0,
2844 	    ("uma_zone_set_zfini on non-empty keg"));
2845 	zone->uz_fini = zfini;
2846 	ZONE_UNLOCK(zone);
2847 }
2848 
2849 /* See uma.h */
2850 /* XXX uk_freef is not actually used with the zone locked */
2851 void
2852 uma_zone_set_freef(uma_zone_t zone, uma_free freef)
2853 {
2854 
2855 	ZONE_LOCK(zone);
2856 	zone_first_keg(zone)->uk_freef = freef;
2857 	ZONE_UNLOCK(zone);
2858 }
2859 
2860 /* See uma.h */
2861 /* XXX uk_allocf is not actually used with the zone locked */
2862 void
2863 uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf)
2864 {
2865 	uma_keg_t keg;
2866 
2867 	ZONE_LOCK(zone);
2868 	keg = zone_first_keg(zone);
2869 	keg->uk_flags |= UMA_ZFLAG_PRIVALLOC;
2870 	keg->uk_allocf = allocf;
2871 	ZONE_UNLOCK(zone);
2872 }
2873 
2874 /* See uma.h */
2875 int
2876 uma_zone_set_obj(uma_zone_t zone, struct vm_object *obj, int count)
2877 {
2878 	uma_keg_t keg;
2879 	vm_offset_t kva;
2880 	int pages;
2881 
2882 	keg = zone_first_keg(zone);
2883 	pages = count / keg->uk_ipers;
2884 
2885 	if (pages * keg->uk_ipers < count)
2886 		pages++;
2887 
2888 	kva = kmem_alloc_nofault(kernel_map, pages * UMA_SLAB_SIZE);
2889 
2890 	if (kva == 0)
2891 		return (0);
2892 	if (obj == NULL) {
2893 		obj = vm_object_allocate(OBJT_DEFAULT,
2894 		    pages);
2895 	} else {
2896 		VM_OBJECT_LOCK_INIT(obj, "uma object");
2897 		_vm_object_allocate(OBJT_DEFAULT,
2898 		    pages, obj);
2899 	}
2900 	ZONE_LOCK(zone);
2901 	keg->uk_kva = kva;
2902 	keg->uk_obj = obj;
2903 	keg->uk_maxpages = pages;
2904 	keg->uk_allocf = obj_alloc;
2905 	keg->uk_flags |= UMA_ZONE_NOFREE | UMA_ZFLAG_PRIVALLOC;
2906 	ZONE_UNLOCK(zone);
2907 	return (1);
2908 }
2909 
2910 /* See uma.h */
2911 void
2912 uma_prealloc(uma_zone_t zone, int items)
2913 {
2914 	int slabs;
2915 	uma_slab_t slab;
2916 	uma_keg_t keg;
2917 
2918 	keg = zone_first_keg(zone);
2919 	ZONE_LOCK(zone);
2920 	slabs = items / keg->uk_ipers;
2921 	if (slabs * keg->uk_ipers < items)
2922 		slabs++;
2923 	while (slabs > 0) {
2924 		slab = keg_alloc_slab(keg, zone, M_WAITOK);
2925 		if (slab == NULL)
2926 			break;
2927 		MPASS(slab->us_keg == keg);
2928 		LIST_INSERT_HEAD(&keg->uk_free_slab, slab, us_link);
2929 		slabs--;
2930 	}
2931 	ZONE_UNLOCK(zone);
2932 }
2933 
2934 /* See uma.h */
2935 u_int32_t *
2936 uma_find_refcnt(uma_zone_t zone, void *item)
2937 {
2938 	uma_slabrefcnt_t slabref;
2939 	uma_keg_t keg;
2940 	u_int32_t *refcnt;
2941 	int idx;
2942 
2943 	slabref = (uma_slabrefcnt_t)vtoslab((vm_offset_t)item &
2944 	    (~UMA_SLAB_MASK));
2945 	keg = slabref->us_keg;
2946 	KASSERT(slabref != NULL && slabref->us_keg->uk_flags & UMA_ZONE_REFCNT,
2947 	    ("uma_find_refcnt(): zone possibly not UMA_ZONE_REFCNT"));
2948 	idx = ((unsigned long)item - (unsigned long)slabref->us_data)
2949 	    / keg->uk_rsize;
2950 	refcnt = &slabref->us_freelist[idx].us_refcnt;
2951 	return refcnt;
2952 }
2953 
2954 /* See uma.h */
2955 void
2956 uma_reclaim(void)
2957 {
2958 #ifdef UMA_DEBUG
2959 	printf("UMA: vm asked us to release pages!\n");
2960 #endif
2961 	bucket_enable();
2962 	zone_foreach(zone_drain);
2963 	/*
2964 	 * Some slabs may have been freed but this zone will be visited early
2965 	 * we visit again so that we can free pages that are empty once other
2966 	 * zones are drained.  We have to do the same for buckets.
2967 	 */
2968 	zone_drain(slabzone);
2969 	zone_drain(slabrefzone);
2970 	bucket_zone_drain();
2971 }
2972 
2973 /* See uma.h */
2974 int
2975 uma_zone_exhausted(uma_zone_t zone)
2976 {
2977 	int full;
2978 
2979 	ZONE_LOCK(zone);
2980 	full = (zone->uz_flags & UMA_ZFLAG_FULL);
2981 	ZONE_UNLOCK(zone);
2982 	return (full);
2983 }
2984 
2985 int
2986 uma_zone_exhausted_nolock(uma_zone_t zone)
2987 {
2988 	return (zone->uz_flags & UMA_ZFLAG_FULL);
2989 }
2990 
2991 void *
2992 uma_large_malloc(int size, int wait)
2993 {
2994 	void *mem;
2995 	uma_slab_t slab;
2996 	u_int8_t flags;
2997 
2998 	slab = zone_alloc_item(slabzone, NULL, wait);
2999 	if (slab == NULL)
3000 		return (NULL);
3001 	mem = page_alloc(NULL, size, &flags, wait);
3002 	if (mem) {
3003 		vsetslab((vm_offset_t)mem, slab);
3004 		slab->us_data = mem;
3005 		slab->us_flags = flags | UMA_SLAB_MALLOC;
3006 		slab->us_size = size;
3007 	} else {
3008 		zone_free_item(slabzone, slab, NULL, SKIP_NONE,
3009 		    ZFREE_STATFAIL | ZFREE_STATFREE);
3010 	}
3011 
3012 	return (mem);
3013 }
3014 
3015 void
3016 uma_large_free(uma_slab_t slab)
3017 {
3018 	vsetobj((vm_offset_t)slab->us_data, kmem_object);
3019 	page_free(slab->us_data, slab->us_size, slab->us_flags);
3020 	zone_free_item(slabzone, slab, NULL, SKIP_NONE, ZFREE_STATFREE);
3021 }
3022 
3023 void
3024 uma_print_stats(void)
3025 {
3026 	zone_foreach(uma_print_zone);
3027 }
3028 
3029 static void
3030 slab_print(uma_slab_t slab)
3031 {
3032 	printf("slab: keg %p, data %p, freecount %d, firstfree %d\n",
3033 		slab->us_keg, slab->us_data, slab->us_freecount,
3034 		slab->us_firstfree);
3035 }
3036 
3037 static void
3038 cache_print(uma_cache_t cache)
3039 {
3040 	printf("alloc: %p(%d), free: %p(%d)\n",
3041 		cache->uc_allocbucket,
3042 		cache->uc_allocbucket?cache->uc_allocbucket->ub_cnt:0,
3043 		cache->uc_freebucket,
3044 		cache->uc_freebucket?cache->uc_freebucket->ub_cnt:0);
3045 }
3046 
3047 static void
3048 uma_print_keg(uma_keg_t keg)
3049 {
3050 	uma_slab_t slab;
3051 
3052 	printf("keg: %s(%p) size %d(%d) flags %d ipers %d ppera %d "
3053 	    "out %d free %d limit %d\n",
3054 	    keg->uk_name, keg, keg->uk_size, keg->uk_rsize, keg->uk_flags,
3055 	    keg->uk_ipers, keg->uk_ppera,
3056 	    (keg->uk_ipers * keg->uk_pages) - keg->uk_free, keg->uk_free,
3057 	    (keg->uk_maxpages / keg->uk_ppera) * keg->uk_ipers);
3058 	printf("Part slabs:\n");
3059 	LIST_FOREACH(slab, &keg->uk_part_slab, us_link)
3060 		slab_print(slab);
3061 	printf("Free slabs:\n");
3062 	LIST_FOREACH(slab, &keg->uk_free_slab, us_link)
3063 		slab_print(slab);
3064 	printf("Full slabs:\n");
3065 	LIST_FOREACH(slab, &keg->uk_full_slab, us_link)
3066 		slab_print(slab);
3067 }
3068 
3069 void
3070 uma_print_zone(uma_zone_t zone)
3071 {
3072 	uma_cache_t cache;
3073 	uma_klink_t kl;
3074 	int i;
3075 
3076 	printf("zone: %s(%p) size %d flags %d\n",
3077 	    zone->uz_name, zone, zone->uz_size, zone->uz_flags);
3078 	LIST_FOREACH(kl, &zone->uz_kegs, kl_link)
3079 		uma_print_keg(kl->kl_keg);
3080 	for (i = 0; i <= mp_maxid; i++) {
3081 		if (CPU_ABSENT(i))
3082 			continue;
3083 		cache = &zone->uz_cpu[i];
3084 		printf("CPU %d Cache:\n", i);
3085 		cache_print(cache);
3086 	}
3087 }
3088 
3089 #ifdef DDB
3090 /*
3091  * Generate statistics across both the zone and its per-cpu cache's.  Return
3092  * desired statistics if the pointer is non-NULL for that statistic.
3093  *
3094  * Note: does not update the zone statistics, as it can't safely clear the
3095  * per-CPU cache statistic.
3096  *
3097  * XXXRW: Following the uc_allocbucket and uc_freebucket pointers here isn't
3098  * safe from off-CPU; we should modify the caches to track this information
3099  * directly so that we don't have to.
3100  */
3101 static void
3102 uma_zone_sumstat(uma_zone_t z, int *cachefreep, u_int64_t *allocsp,
3103     u_int64_t *freesp)
3104 {
3105 	uma_cache_t cache;
3106 	u_int64_t allocs, frees;
3107 	int cachefree, cpu;
3108 
3109 	allocs = frees = 0;
3110 	cachefree = 0;
3111 	for (cpu = 0; cpu <= mp_maxid; cpu++) {
3112 		if (CPU_ABSENT(cpu))
3113 			continue;
3114 		cache = &z->uz_cpu[cpu];
3115 		if (cache->uc_allocbucket != NULL)
3116 			cachefree += cache->uc_allocbucket->ub_cnt;
3117 		if (cache->uc_freebucket != NULL)
3118 			cachefree += cache->uc_freebucket->ub_cnt;
3119 		allocs += cache->uc_allocs;
3120 		frees += cache->uc_frees;
3121 	}
3122 	allocs += z->uz_allocs;
3123 	frees += z->uz_frees;
3124 	if (cachefreep != NULL)
3125 		*cachefreep = cachefree;
3126 	if (allocsp != NULL)
3127 		*allocsp = allocs;
3128 	if (freesp != NULL)
3129 		*freesp = frees;
3130 }
3131 #endif /* DDB */
3132 
3133 static int
3134 sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS)
3135 {
3136 	uma_keg_t kz;
3137 	uma_zone_t z;
3138 	int count;
3139 
3140 	count = 0;
3141 	mtx_lock(&uma_mtx);
3142 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3143 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
3144 			count++;
3145 	}
3146 	mtx_unlock(&uma_mtx);
3147 	return (sysctl_handle_int(oidp, &count, 0, req));
3148 }
3149 
3150 static int
3151 sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS)
3152 {
3153 	struct uma_stream_header ush;
3154 	struct uma_type_header uth;
3155 	struct uma_percpu_stat ups;
3156 	uma_bucket_t bucket;
3157 	struct sbuf sbuf;
3158 	uma_cache_t cache;
3159 	uma_klink_t kl;
3160 	uma_keg_t kz;
3161 	uma_zone_t z;
3162 	uma_keg_t k;
3163 	char *buffer;
3164 	int buflen, count, error, i;
3165 
3166 	mtx_lock(&uma_mtx);
3167 restart:
3168 	mtx_assert(&uma_mtx, MA_OWNED);
3169 	count = 0;
3170 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3171 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
3172 			count++;
3173 	}
3174 	mtx_unlock(&uma_mtx);
3175 
3176 	buflen = sizeof(ush) + count * (sizeof(uth) + sizeof(ups) *
3177 	    (mp_maxid + 1)) + 1;
3178 	buffer = malloc(buflen, M_TEMP, M_WAITOK | M_ZERO);
3179 
3180 	mtx_lock(&uma_mtx);
3181 	i = 0;
3182 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3183 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
3184 			i++;
3185 	}
3186 	if (i > count) {
3187 		free(buffer, M_TEMP);
3188 		goto restart;
3189 	}
3190 	count =  i;
3191 
3192 	sbuf_new(&sbuf, buffer, buflen, SBUF_FIXEDLEN);
3193 
3194 	/*
3195 	 * Insert stream header.
3196 	 */
3197 	bzero(&ush, sizeof(ush));
3198 	ush.ush_version = UMA_STREAM_VERSION;
3199 	ush.ush_maxcpus = (mp_maxid + 1);
3200 	ush.ush_count = count;
3201 	if (sbuf_bcat(&sbuf, &ush, sizeof(ush)) < 0) {
3202 		mtx_unlock(&uma_mtx);
3203 		error = ENOMEM;
3204 		goto out;
3205 	}
3206 
3207 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3208 		LIST_FOREACH(z, &kz->uk_zones, uz_link) {
3209 			bzero(&uth, sizeof(uth));
3210 			ZONE_LOCK(z);
3211 			strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
3212 			uth.uth_align = kz->uk_align;
3213 			uth.uth_size = kz->uk_size;
3214 			uth.uth_rsize = kz->uk_rsize;
3215 			LIST_FOREACH(kl, &z->uz_kegs, kl_link) {
3216 				k = kl->kl_keg;
3217 				uth.uth_maxpages += k->uk_maxpages;
3218 				uth.uth_pages += k->uk_pages;
3219 				uth.uth_keg_free += k->uk_free;
3220 				uth.uth_limit = (k->uk_maxpages / k->uk_ppera)
3221 				    * k->uk_ipers;
3222 			}
3223 
3224 			/*
3225 			 * A zone is secondary is it is not the first entry
3226 			 * on the keg's zone list.
3227 			 */
3228 			if ((z->uz_flags & UMA_ZONE_SECONDARY) &&
3229 			    (LIST_FIRST(&kz->uk_zones) != z))
3230 				uth.uth_zone_flags = UTH_ZONE_SECONDARY;
3231 
3232 			LIST_FOREACH(bucket, &z->uz_full_bucket, ub_link)
3233 				uth.uth_zone_free += bucket->ub_cnt;
3234 			uth.uth_allocs = z->uz_allocs;
3235 			uth.uth_frees = z->uz_frees;
3236 			uth.uth_fails = z->uz_fails;
3237 			if (sbuf_bcat(&sbuf, &uth, sizeof(uth)) < 0) {
3238 				ZONE_UNLOCK(z);
3239 				mtx_unlock(&uma_mtx);
3240 				error = ENOMEM;
3241 				goto out;
3242 			}
3243 			/*
3244 			 * While it is not normally safe to access the cache
3245 			 * bucket pointers while not on the CPU that owns the
3246 			 * cache, we only allow the pointers to be exchanged
3247 			 * without the zone lock held, not invalidated, so
3248 			 * accept the possible race associated with bucket
3249 			 * exchange during monitoring.
3250 			 */
3251 			for (i = 0; i < (mp_maxid + 1); i++) {
3252 				bzero(&ups, sizeof(ups));
3253 				if (kz->uk_flags & UMA_ZFLAG_INTERNAL)
3254 					goto skip;
3255 				if (CPU_ABSENT(i))
3256 					goto skip;
3257 				cache = &z->uz_cpu[i];
3258 				if (cache->uc_allocbucket != NULL)
3259 					ups.ups_cache_free +=
3260 					    cache->uc_allocbucket->ub_cnt;
3261 				if (cache->uc_freebucket != NULL)
3262 					ups.ups_cache_free +=
3263 					    cache->uc_freebucket->ub_cnt;
3264 				ups.ups_allocs = cache->uc_allocs;
3265 				ups.ups_frees = cache->uc_frees;
3266 skip:
3267 				if (sbuf_bcat(&sbuf, &ups, sizeof(ups)) < 0) {
3268 					ZONE_UNLOCK(z);
3269 					mtx_unlock(&uma_mtx);
3270 					error = ENOMEM;
3271 					goto out;
3272 				}
3273 			}
3274 			ZONE_UNLOCK(z);
3275 		}
3276 	}
3277 	mtx_unlock(&uma_mtx);
3278 	sbuf_finish(&sbuf);
3279 	error = SYSCTL_OUT(req, sbuf_data(&sbuf), sbuf_len(&sbuf));
3280 out:
3281 	free(buffer, M_TEMP);
3282 	return (error);
3283 }
3284 
3285 #ifdef DDB
3286 DB_SHOW_COMMAND(uma, db_show_uma)
3287 {
3288 	u_int64_t allocs, frees;
3289 	uma_bucket_t bucket;
3290 	uma_keg_t kz;
3291 	uma_zone_t z;
3292 	int cachefree;
3293 
3294 	db_printf("%18s %8s %8s %8s %12s\n", "Zone", "Size", "Used", "Free",
3295 	    "Requests");
3296 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3297 		LIST_FOREACH(z, &kz->uk_zones, uz_link) {
3298 			if (kz->uk_flags & UMA_ZFLAG_INTERNAL) {
3299 				allocs = z->uz_allocs;
3300 				frees = z->uz_frees;
3301 				cachefree = 0;
3302 			} else
3303 				uma_zone_sumstat(z, &cachefree, &allocs,
3304 				    &frees);
3305 			if (!((z->uz_flags & UMA_ZONE_SECONDARY) &&
3306 			    (LIST_FIRST(&kz->uk_zones) != z)))
3307 				cachefree += kz->uk_free;
3308 			LIST_FOREACH(bucket, &z->uz_full_bucket, ub_link)
3309 				cachefree += bucket->ub_cnt;
3310 			db_printf("%18s %8ju %8jd %8d %12ju\n", z->uz_name,
3311 			    (uintmax_t)kz->uk_size,
3312 			    (intmax_t)(allocs - frees), cachefree,
3313 			    (uintmax_t)allocs);
3314 		}
3315 	}
3316 }
3317 #endif
3318