xref: /freebsd/sys/vm/uma_core.c (revision bcce9a2b33a8e9187a63f435726a7a801e89f326)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2002-2005, 2009, 2013 Jeffrey Roberson <jeff@FreeBSD.org>
5  * Copyright (c) 2004, 2005 Bosko Milekic <bmilekic@FreeBSD.org>
6  * Copyright (c) 2004-2006 Robert N. M. Watson
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice unmodified, this list of conditions, and the following
14  *    disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 /*
32  * uma_core.c  Implementation of the Universal Memory allocator
33  *
34  * This allocator is intended to replace the multitude of similar object caches
35  * in the standard FreeBSD kernel.  The intent is to be flexible as well as
36  * efficient.  A primary design goal is to return unused memory to the rest of
37  * the system.  This will make the system as a whole more flexible due to the
38  * ability to move memory to subsystems which most need it instead of leaving
39  * pools of reserved memory unused.
40  *
41  * The basic ideas stem from similar slab/zone based allocators whose algorithms
42  * are well known.
43  *
44  */
45 
46 /*
47  * TODO:
48  *	- Improve memory usage for large allocations
49  *	- Investigate cache size adjustments
50  */
51 
52 #include <sys/cdefs.h>
53 __FBSDID("$FreeBSD$");
54 
55 #include "opt_ddb.h"
56 #include "opt_param.h"
57 #include "opt_vm.h"
58 
59 #include <sys/param.h>
60 #include <sys/systm.h>
61 #include <sys/bitset.h>
62 #include <sys/eventhandler.h>
63 #include <sys/kernel.h>
64 #include <sys/types.h>
65 #include <sys/limits.h>
66 #include <sys/queue.h>
67 #include <sys/malloc.h>
68 #include <sys/ktr.h>
69 #include <sys/lock.h>
70 #include <sys/sysctl.h>
71 #include <sys/mutex.h>
72 #include <sys/proc.h>
73 #include <sys/random.h>
74 #include <sys/rwlock.h>
75 #include <sys/sbuf.h>
76 #include <sys/sched.h>
77 #include <sys/smp.h>
78 #include <sys/taskqueue.h>
79 #include <sys/vmmeter.h>
80 
81 #include <vm/vm.h>
82 #include <vm/vm_object.h>
83 #include <vm/vm_page.h>
84 #include <vm/vm_pageout.h>
85 #include <vm/vm_param.h>
86 #include <vm/vm_phys.h>
87 #include <vm/vm_map.h>
88 #include <vm/vm_kern.h>
89 #include <vm/vm_extern.h>
90 #include <vm/uma.h>
91 #include <vm/uma_int.h>
92 #include <vm/uma_dbg.h>
93 
94 #include <ddb/ddb.h>
95 
96 #ifdef DEBUG_MEMGUARD
97 #include <vm/memguard.h>
98 #endif
99 
100 /*
101  * This is the zone and keg from which all zones are spawned.
102  */
103 static uma_zone_t kegs;
104 static uma_zone_t zones;
105 
106 /* This is the zone from which all offpage uma_slab_ts are allocated. */
107 static uma_zone_t slabzone;
108 
109 /*
110  * The initial hash tables come out of this zone so they can be allocated
111  * prior to malloc coming up.
112  */
113 static uma_zone_t hashzone;
114 
115 /* The boot-time adjusted value for cache line alignment. */
116 int uma_align_cache = 64 - 1;
117 
118 static MALLOC_DEFINE(M_UMAHASH, "UMAHash", "UMA Hash Buckets");
119 
120 /*
121  * Are we allowed to allocate buckets?
122  */
123 static int bucketdisable = 1;
124 
125 /* Linked list of all kegs in the system */
126 static LIST_HEAD(,uma_keg) uma_kegs = LIST_HEAD_INITIALIZER(uma_kegs);
127 
128 /* Linked list of all cache-only zones in the system */
129 static LIST_HEAD(,uma_zone) uma_cachezones =
130     LIST_HEAD_INITIALIZER(uma_cachezones);
131 
132 /* This RW lock protects the keg list */
133 static struct rwlock_padalign __exclusive_cache_line uma_rwlock;
134 
135 /*
136  * Pointer and counter to pool of pages, that is preallocated at
137  * startup to bootstrap UMA.
138  */
139 static char *bootmem;
140 static int boot_pages;
141 
142 static struct sx uma_drain_lock;
143 
144 /* kmem soft limit. */
145 static unsigned long uma_kmem_limit = LONG_MAX;
146 static volatile unsigned long uma_kmem_total;
147 
148 /* Is the VM done starting up? */
149 static enum { BOOT_COLD = 0, BOOT_STRAPPED, BOOT_PAGEALLOC, BOOT_BUCKETS,
150     BOOT_RUNNING } booted = BOOT_COLD;
151 
152 /*
153  * This is the handle used to schedule events that need to happen
154  * outside of the allocation fast path.
155  */
156 static struct callout uma_callout;
157 #define	UMA_TIMEOUT	20		/* Seconds for callout interval. */
158 
159 /*
160  * This structure is passed as the zone ctor arg so that I don't have to create
161  * a special allocation function just for zones.
162  */
163 struct uma_zctor_args {
164 	const char *name;
165 	size_t size;
166 	uma_ctor ctor;
167 	uma_dtor dtor;
168 	uma_init uminit;
169 	uma_fini fini;
170 	uma_import import;
171 	uma_release release;
172 	void *arg;
173 	uma_keg_t keg;
174 	int align;
175 	uint32_t flags;
176 };
177 
178 struct uma_kctor_args {
179 	uma_zone_t zone;
180 	size_t size;
181 	uma_init uminit;
182 	uma_fini fini;
183 	int align;
184 	uint32_t flags;
185 };
186 
187 struct uma_bucket_zone {
188 	uma_zone_t	ubz_zone;
189 	char		*ubz_name;
190 	int		ubz_entries;	/* Number of items it can hold. */
191 	int		ubz_maxsize;	/* Maximum allocation size per-item. */
192 };
193 
194 /*
195  * Compute the actual number of bucket entries to pack them in power
196  * of two sizes for more efficient space utilization.
197  */
198 #define	BUCKET_SIZE(n)						\
199     (((sizeof(void *) * (n)) - sizeof(struct uma_bucket)) / sizeof(void *))
200 
201 #define	BUCKET_MAX	BUCKET_SIZE(256)
202 
203 struct uma_bucket_zone bucket_zones[] = {
204 	{ NULL, "4 Bucket", BUCKET_SIZE(4), 4096 },
205 	{ NULL, "6 Bucket", BUCKET_SIZE(6), 3072 },
206 	{ NULL, "8 Bucket", BUCKET_SIZE(8), 2048 },
207 	{ NULL, "12 Bucket", BUCKET_SIZE(12), 1536 },
208 	{ NULL, "16 Bucket", BUCKET_SIZE(16), 1024 },
209 	{ NULL, "32 Bucket", BUCKET_SIZE(32), 512 },
210 	{ NULL, "64 Bucket", BUCKET_SIZE(64), 256 },
211 	{ NULL, "128 Bucket", BUCKET_SIZE(128), 128 },
212 	{ NULL, "256 Bucket", BUCKET_SIZE(256), 64 },
213 	{ NULL, NULL, 0}
214 };
215 
216 /*
217  * Flags and enumerations to be passed to internal functions.
218  */
219 enum zfreeskip { SKIP_NONE = 0, SKIP_DTOR, SKIP_FINI };
220 
221 #define	UMA_ANYDOMAIN	-1	/* Special value for domain search. */
222 
223 /* Prototypes.. */
224 
225 int	uma_startup_count(int);
226 void	uma_startup(void *, int);
227 void	uma_startup1(void);
228 void	uma_startup2(void);
229 
230 static void *noobj_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
231 static void *page_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
232 static void *startup_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
233 static void page_free(void *, vm_size_t, uint8_t);
234 static uma_slab_t keg_alloc_slab(uma_keg_t, uma_zone_t, int, int);
235 static void cache_drain(uma_zone_t);
236 static void bucket_drain(uma_zone_t, uma_bucket_t);
237 static void bucket_cache_drain(uma_zone_t zone);
238 static int keg_ctor(void *, int, void *, int);
239 static void keg_dtor(void *, int, void *);
240 static int zone_ctor(void *, int, void *, int);
241 static void zone_dtor(void *, int, void *);
242 static int zero_init(void *, int, int);
243 static void keg_small_init(uma_keg_t keg);
244 static void keg_large_init(uma_keg_t keg);
245 static void zone_foreach(void (*zfunc)(uma_zone_t));
246 static void zone_timeout(uma_zone_t zone);
247 static int hash_alloc(struct uma_hash *);
248 static int hash_expand(struct uma_hash *, struct uma_hash *);
249 static void hash_free(struct uma_hash *hash);
250 static void uma_timeout(void *);
251 static void uma_startup3(void);
252 static void *zone_alloc_item(uma_zone_t, void *, int, int);
253 static void zone_free_item(uma_zone_t, void *, void *, enum zfreeskip);
254 static void bucket_enable(void);
255 static void bucket_init(void);
256 static uma_bucket_t bucket_alloc(uma_zone_t zone, void *, int);
257 static void bucket_free(uma_zone_t zone, uma_bucket_t, void *);
258 static void bucket_zone_drain(void);
259 static uma_bucket_t zone_alloc_bucket(uma_zone_t, void *, int, int);
260 static uma_slab_t zone_fetch_slab(uma_zone_t, uma_keg_t, int, int);
261 static uma_slab_t zone_fetch_slab_multi(uma_zone_t, uma_keg_t, int, int);
262 static void *slab_alloc_item(uma_keg_t keg, uma_slab_t slab);
263 static void slab_free_item(uma_keg_t keg, uma_slab_t slab, void *item);
264 static uma_keg_t uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit,
265     uma_fini fini, int align, uint32_t flags);
266 static int zone_import(uma_zone_t, void **, int, int, int);
267 static void zone_release(uma_zone_t, void **, int);
268 static void uma_zero_item(void *, uma_zone_t);
269 
270 void uma_print_zone(uma_zone_t);
271 void uma_print_stats(void);
272 static int sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS);
273 static int sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS);
274 
275 #ifdef INVARIANTS
276 static void uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item);
277 static void uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item);
278 #endif
279 
280 SYSINIT(uma_startup3, SI_SUB_VM_CONF, SI_ORDER_SECOND, uma_startup3, NULL);
281 
282 SYSCTL_PROC(_vm, OID_AUTO, zone_count, CTLFLAG_RD|CTLTYPE_INT,
283     0, 0, sysctl_vm_zone_count, "I", "Number of UMA zones");
284 
285 SYSCTL_PROC(_vm, OID_AUTO, zone_stats, CTLFLAG_RD|CTLTYPE_STRUCT,
286     0, 0, sysctl_vm_zone_stats, "s,struct uma_type_header", "Zone Stats");
287 
288 static int zone_warnings = 1;
289 SYSCTL_INT(_vm, OID_AUTO, zone_warnings, CTLFLAG_RWTUN, &zone_warnings, 0,
290     "Warn when UMA zones becomes full");
291 
292 /* Adjust bytes under management by UMA. */
293 static inline void
294 uma_total_dec(unsigned long size)
295 {
296 
297 	atomic_subtract_long(&uma_kmem_total, size);
298 }
299 
300 static inline void
301 uma_total_inc(unsigned long size)
302 {
303 
304 	if (atomic_fetchadd_long(&uma_kmem_total, size) > uma_kmem_limit)
305 		uma_reclaim_wakeup();
306 }
307 
308 /*
309  * This routine checks to see whether or not it's safe to enable buckets.
310  */
311 static void
312 bucket_enable(void)
313 {
314 	bucketdisable = vm_page_count_min();
315 }
316 
317 /*
318  * Initialize bucket_zones, the array of zones of buckets of various sizes.
319  *
320  * For each zone, calculate the memory required for each bucket, consisting
321  * of the header and an array of pointers.
322  */
323 static void
324 bucket_init(void)
325 {
326 	struct uma_bucket_zone *ubz;
327 	int size;
328 
329 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++) {
330 		size = roundup(sizeof(struct uma_bucket), sizeof(void *));
331 		size += sizeof(void *) * ubz->ubz_entries;
332 		ubz->ubz_zone = uma_zcreate(ubz->ubz_name, size,
333 		    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR,
334 		    UMA_ZONE_MTXCLASS | UMA_ZFLAG_BUCKET | UMA_ZONE_NUMA);
335 	}
336 }
337 
338 /*
339  * Given a desired number of entries for a bucket, return the zone from which
340  * to allocate the bucket.
341  */
342 static struct uma_bucket_zone *
343 bucket_zone_lookup(int entries)
344 {
345 	struct uma_bucket_zone *ubz;
346 
347 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
348 		if (ubz->ubz_entries >= entries)
349 			return (ubz);
350 	ubz--;
351 	return (ubz);
352 }
353 
354 static int
355 bucket_select(int size)
356 {
357 	struct uma_bucket_zone *ubz;
358 
359 	ubz = &bucket_zones[0];
360 	if (size > ubz->ubz_maxsize)
361 		return MAX((ubz->ubz_maxsize * ubz->ubz_entries) / size, 1);
362 
363 	for (; ubz->ubz_entries != 0; ubz++)
364 		if (ubz->ubz_maxsize < size)
365 			break;
366 	ubz--;
367 	return (ubz->ubz_entries);
368 }
369 
370 static uma_bucket_t
371 bucket_alloc(uma_zone_t zone, void *udata, int flags)
372 {
373 	struct uma_bucket_zone *ubz;
374 	uma_bucket_t bucket;
375 
376 	/*
377 	 * This is to stop us from allocating per cpu buckets while we're
378 	 * running out of vm.boot_pages.  Otherwise, we would exhaust the
379 	 * boot pages.  This also prevents us from allocating buckets in
380 	 * low memory situations.
381 	 */
382 	if (bucketdisable)
383 		return (NULL);
384 	/*
385 	 * To limit bucket recursion we store the original zone flags
386 	 * in a cookie passed via zalloc_arg/zfree_arg.  This allows the
387 	 * NOVM flag to persist even through deep recursions.  We also
388 	 * store ZFLAG_BUCKET once we have recursed attempting to allocate
389 	 * a bucket for a bucket zone so we do not allow infinite bucket
390 	 * recursion.  This cookie will even persist to frees of unused
391 	 * buckets via the allocation path or bucket allocations in the
392 	 * free path.
393 	 */
394 	if ((zone->uz_flags & UMA_ZFLAG_BUCKET) == 0)
395 		udata = (void *)(uintptr_t)zone->uz_flags;
396 	else {
397 		if ((uintptr_t)udata & UMA_ZFLAG_BUCKET)
398 			return (NULL);
399 		udata = (void *)((uintptr_t)udata | UMA_ZFLAG_BUCKET);
400 	}
401 	if ((uintptr_t)udata & UMA_ZFLAG_CACHEONLY)
402 		flags |= M_NOVM;
403 	ubz = bucket_zone_lookup(zone->uz_count);
404 	if (ubz->ubz_zone == zone && (ubz + 1)->ubz_entries != 0)
405 		ubz++;
406 	bucket = uma_zalloc_arg(ubz->ubz_zone, udata, flags);
407 	if (bucket) {
408 #ifdef INVARIANTS
409 		bzero(bucket->ub_bucket, sizeof(void *) * ubz->ubz_entries);
410 #endif
411 		bucket->ub_cnt = 0;
412 		bucket->ub_entries = ubz->ubz_entries;
413 	}
414 
415 	return (bucket);
416 }
417 
418 static void
419 bucket_free(uma_zone_t zone, uma_bucket_t bucket, void *udata)
420 {
421 	struct uma_bucket_zone *ubz;
422 
423 	KASSERT(bucket->ub_cnt == 0,
424 	    ("bucket_free: Freeing a non free bucket."));
425 	if ((zone->uz_flags & UMA_ZFLAG_BUCKET) == 0)
426 		udata = (void *)(uintptr_t)zone->uz_flags;
427 	ubz = bucket_zone_lookup(bucket->ub_entries);
428 	uma_zfree_arg(ubz->ubz_zone, bucket, udata);
429 }
430 
431 static void
432 bucket_zone_drain(void)
433 {
434 	struct uma_bucket_zone *ubz;
435 
436 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
437 		zone_drain(ubz->ubz_zone);
438 }
439 
440 static void
441 zone_log_warning(uma_zone_t zone)
442 {
443 	static const struct timeval warninterval = { 300, 0 };
444 
445 	if (!zone_warnings || zone->uz_warning == NULL)
446 		return;
447 
448 	if (ratecheck(&zone->uz_ratecheck, &warninterval))
449 		printf("[zone: %s] %s\n", zone->uz_name, zone->uz_warning);
450 }
451 
452 static inline void
453 zone_maxaction(uma_zone_t zone)
454 {
455 
456 	if (zone->uz_maxaction.ta_func != NULL)
457 		taskqueue_enqueue(taskqueue_thread, &zone->uz_maxaction);
458 }
459 
460 static void
461 zone_foreach_keg(uma_zone_t zone, void (*kegfn)(uma_keg_t))
462 {
463 	uma_klink_t klink;
464 
465 	LIST_FOREACH(klink, &zone->uz_kegs, kl_link)
466 		kegfn(klink->kl_keg);
467 }
468 
469 /*
470  * Routine called by timeout which is used to fire off some time interval
471  * based calculations.  (stats, hash size, etc.)
472  *
473  * Arguments:
474  *	arg   Unused
475  *
476  * Returns:
477  *	Nothing
478  */
479 static void
480 uma_timeout(void *unused)
481 {
482 	bucket_enable();
483 	zone_foreach(zone_timeout);
484 
485 	/* Reschedule this event */
486 	callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
487 }
488 
489 /*
490  * Routine to perform timeout driven calculations.  This expands the
491  * hashes and does per cpu statistics aggregation.
492  *
493  *  Returns nothing.
494  */
495 static void
496 keg_timeout(uma_keg_t keg)
497 {
498 
499 	KEG_LOCK(keg);
500 	/*
501 	 * Expand the keg hash table.
502 	 *
503 	 * This is done if the number of slabs is larger than the hash size.
504 	 * What I'm trying to do here is completely reduce collisions.  This
505 	 * may be a little aggressive.  Should I allow for two collisions max?
506 	 */
507 	if (keg->uk_flags & UMA_ZONE_HASH &&
508 	    keg->uk_pages / keg->uk_ppera >= keg->uk_hash.uh_hashsize) {
509 		struct uma_hash newhash;
510 		struct uma_hash oldhash;
511 		int ret;
512 
513 		/*
514 		 * This is so involved because allocating and freeing
515 		 * while the keg lock is held will lead to deadlock.
516 		 * I have to do everything in stages and check for
517 		 * races.
518 		 */
519 		newhash = keg->uk_hash;
520 		KEG_UNLOCK(keg);
521 		ret = hash_alloc(&newhash);
522 		KEG_LOCK(keg);
523 		if (ret) {
524 			if (hash_expand(&keg->uk_hash, &newhash)) {
525 				oldhash = keg->uk_hash;
526 				keg->uk_hash = newhash;
527 			} else
528 				oldhash = newhash;
529 
530 			KEG_UNLOCK(keg);
531 			hash_free(&oldhash);
532 			return;
533 		}
534 	}
535 	KEG_UNLOCK(keg);
536 }
537 
538 static void
539 zone_timeout(uma_zone_t zone)
540 {
541 
542 	zone_foreach_keg(zone, &keg_timeout);
543 }
544 
545 /*
546  * Allocate and zero fill the next sized hash table from the appropriate
547  * backing store.
548  *
549  * Arguments:
550  *	hash  A new hash structure with the old hash size in uh_hashsize
551  *
552  * Returns:
553  *	1 on success and 0 on failure.
554  */
555 static int
556 hash_alloc(struct uma_hash *hash)
557 {
558 	int oldsize;
559 	int alloc;
560 
561 	oldsize = hash->uh_hashsize;
562 
563 	/* We're just going to go to a power of two greater */
564 	if (oldsize)  {
565 		hash->uh_hashsize = oldsize * 2;
566 		alloc = sizeof(hash->uh_slab_hash[0]) * hash->uh_hashsize;
567 		hash->uh_slab_hash = (struct slabhead *)malloc(alloc,
568 		    M_UMAHASH, M_NOWAIT);
569 	} else {
570 		alloc = sizeof(hash->uh_slab_hash[0]) * UMA_HASH_SIZE_INIT;
571 		hash->uh_slab_hash = zone_alloc_item(hashzone, NULL,
572 		    UMA_ANYDOMAIN, M_WAITOK);
573 		hash->uh_hashsize = UMA_HASH_SIZE_INIT;
574 	}
575 	if (hash->uh_slab_hash) {
576 		bzero(hash->uh_slab_hash, alloc);
577 		hash->uh_hashmask = hash->uh_hashsize - 1;
578 		return (1);
579 	}
580 
581 	return (0);
582 }
583 
584 /*
585  * Expands the hash table for HASH zones.  This is done from zone_timeout
586  * to reduce collisions.  This must not be done in the regular allocation
587  * path, otherwise, we can recurse on the vm while allocating pages.
588  *
589  * Arguments:
590  *	oldhash  The hash you want to expand
591  *	newhash  The hash structure for the new table
592  *
593  * Returns:
594  *	Nothing
595  *
596  * Discussion:
597  */
598 static int
599 hash_expand(struct uma_hash *oldhash, struct uma_hash *newhash)
600 {
601 	uma_slab_t slab;
602 	int hval;
603 	int i;
604 
605 	if (!newhash->uh_slab_hash)
606 		return (0);
607 
608 	if (oldhash->uh_hashsize >= newhash->uh_hashsize)
609 		return (0);
610 
611 	/*
612 	 * I need to investigate hash algorithms for resizing without a
613 	 * full rehash.
614 	 */
615 
616 	for (i = 0; i < oldhash->uh_hashsize; i++)
617 		while (!SLIST_EMPTY(&oldhash->uh_slab_hash[i])) {
618 			slab = SLIST_FIRST(&oldhash->uh_slab_hash[i]);
619 			SLIST_REMOVE_HEAD(&oldhash->uh_slab_hash[i], us_hlink);
620 			hval = UMA_HASH(newhash, slab->us_data);
621 			SLIST_INSERT_HEAD(&newhash->uh_slab_hash[hval],
622 			    slab, us_hlink);
623 		}
624 
625 	return (1);
626 }
627 
628 /*
629  * Free the hash bucket to the appropriate backing store.
630  *
631  * Arguments:
632  *	slab_hash  The hash bucket we're freeing
633  *	hashsize   The number of entries in that hash bucket
634  *
635  * Returns:
636  *	Nothing
637  */
638 static void
639 hash_free(struct uma_hash *hash)
640 {
641 	if (hash->uh_slab_hash == NULL)
642 		return;
643 	if (hash->uh_hashsize == UMA_HASH_SIZE_INIT)
644 		zone_free_item(hashzone, hash->uh_slab_hash, NULL, SKIP_NONE);
645 	else
646 		free(hash->uh_slab_hash, M_UMAHASH);
647 }
648 
649 /*
650  * Frees all outstanding items in a bucket
651  *
652  * Arguments:
653  *	zone   The zone to free to, must be unlocked.
654  *	bucket The free/alloc bucket with items, cpu queue must be locked.
655  *
656  * Returns:
657  *	Nothing
658  */
659 
660 static void
661 bucket_drain(uma_zone_t zone, uma_bucket_t bucket)
662 {
663 	int i;
664 
665 	if (bucket == NULL)
666 		return;
667 
668 	if (zone->uz_fini)
669 		for (i = 0; i < bucket->ub_cnt; i++)
670 			zone->uz_fini(bucket->ub_bucket[i], zone->uz_size);
671 	zone->uz_release(zone->uz_arg, bucket->ub_bucket, bucket->ub_cnt);
672 	bucket->ub_cnt = 0;
673 }
674 
675 /*
676  * Drains the per cpu caches for a zone.
677  *
678  * NOTE: This may only be called while the zone is being turn down, and not
679  * during normal operation.  This is necessary in order that we do not have
680  * to migrate CPUs to drain the per-CPU caches.
681  *
682  * Arguments:
683  *	zone     The zone to drain, must be unlocked.
684  *
685  * Returns:
686  *	Nothing
687  */
688 static void
689 cache_drain(uma_zone_t zone)
690 {
691 	uma_cache_t cache;
692 	int cpu;
693 
694 	/*
695 	 * XXX: It is safe to not lock the per-CPU caches, because we're
696 	 * tearing down the zone anyway.  I.e., there will be no further use
697 	 * of the caches at this point.
698 	 *
699 	 * XXX: It would good to be able to assert that the zone is being
700 	 * torn down to prevent improper use of cache_drain().
701 	 *
702 	 * XXX: We lock the zone before passing into bucket_cache_drain() as
703 	 * it is used elsewhere.  Should the tear-down path be made special
704 	 * there in some form?
705 	 */
706 	CPU_FOREACH(cpu) {
707 		cache = &zone->uz_cpu[cpu];
708 		bucket_drain(zone, cache->uc_allocbucket);
709 		bucket_drain(zone, cache->uc_freebucket);
710 		if (cache->uc_allocbucket != NULL)
711 			bucket_free(zone, cache->uc_allocbucket, NULL);
712 		if (cache->uc_freebucket != NULL)
713 			bucket_free(zone, cache->uc_freebucket, NULL);
714 		cache->uc_allocbucket = cache->uc_freebucket = NULL;
715 	}
716 	ZONE_LOCK(zone);
717 	bucket_cache_drain(zone);
718 	ZONE_UNLOCK(zone);
719 }
720 
721 static void
722 cache_shrink(uma_zone_t zone)
723 {
724 
725 	if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
726 		return;
727 
728 	ZONE_LOCK(zone);
729 	zone->uz_count = (zone->uz_count_min + zone->uz_count) / 2;
730 	ZONE_UNLOCK(zone);
731 }
732 
733 static void
734 cache_drain_safe_cpu(uma_zone_t zone)
735 {
736 	uma_cache_t cache;
737 	uma_bucket_t b1, b2;
738 	int domain;
739 
740 	if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
741 		return;
742 
743 	b1 = b2 = NULL;
744 	ZONE_LOCK(zone);
745 	critical_enter();
746 	if (zone->uz_flags & UMA_ZONE_NUMA)
747 		domain = PCPU_GET(domain);
748 	else
749 		domain = 0;
750 	cache = &zone->uz_cpu[curcpu];
751 	if (cache->uc_allocbucket) {
752 		if (cache->uc_allocbucket->ub_cnt != 0)
753 			LIST_INSERT_HEAD(&zone->uz_domain[domain].uzd_buckets,
754 			    cache->uc_allocbucket, ub_link);
755 		else
756 			b1 = cache->uc_allocbucket;
757 		cache->uc_allocbucket = NULL;
758 	}
759 	if (cache->uc_freebucket) {
760 		if (cache->uc_freebucket->ub_cnt != 0)
761 			LIST_INSERT_HEAD(&zone->uz_domain[domain].uzd_buckets,
762 			    cache->uc_freebucket, ub_link);
763 		else
764 			b2 = cache->uc_freebucket;
765 		cache->uc_freebucket = NULL;
766 	}
767 	critical_exit();
768 	ZONE_UNLOCK(zone);
769 	if (b1)
770 		bucket_free(zone, b1, NULL);
771 	if (b2)
772 		bucket_free(zone, b2, NULL);
773 }
774 
775 /*
776  * Safely drain per-CPU caches of a zone(s) to alloc bucket.
777  * This is an expensive call because it needs to bind to all CPUs
778  * one by one and enter a critical section on each of them in order
779  * to safely access their cache buckets.
780  * Zone lock must not be held on call this function.
781  */
782 static void
783 cache_drain_safe(uma_zone_t zone)
784 {
785 	int cpu;
786 
787 	/*
788 	 * Polite bucket sizes shrinking was not enouth, shrink aggressively.
789 	 */
790 	if (zone)
791 		cache_shrink(zone);
792 	else
793 		zone_foreach(cache_shrink);
794 
795 	CPU_FOREACH(cpu) {
796 		thread_lock(curthread);
797 		sched_bind(curthread, cpu);
798 		thread_unlock(curthread);
799 
800 		if (zone)
801 			cache_drain_safe_cpu(zone);
802 		else
803 			zone_foreach(cache_drain_safe_cpu);
804 	}
805 	thread_lock(curthread);
806 	sched_unbind(curthread);
807 	thread_unlock(curthread);
808 }
809 
810 /*
811  * Drain the cached buckets from a zone.  Expects a locked zone on entry.
812  */
813 static void
814 bucket_cache_drain(uma_zone_t zone)
815 {
816 	uma_zone_domain_t zdom;
817 	uma_bucket_t bucket;
818 	int i;
819 
820 	/*
821 	 * Drain the bucket queues and free the buckets.
822 	 */
823 	for (i = 0; i < vm_ndomains; i++) {
824 		zdom = &zone->uz_domain[i];
825 		while ((bucket = LIST_FIRST(&zdom->uzd_buckets)) != NULL) {
826 			LIST_REMOVE(bucket, ub_link);
827 			ZONE_UNLOCK(zone);
828 			bucket_drain(zone, bucket);
829 			bucket_free(zone, bucket, NULL);
830 			ZONE_LOCK(zone);
831 		}
832 	}
833 
834 	/*
835 	 * Shrink further bucket sizes.  Price of single zone lock collision
836 	 * is probably lower then price of global cache drain.
837 	 */
838 	if (zone->uz_count > zone->uz_count_min)
839 		zone->uz_count--;
840 }
841 
842 static void
843 keg_free_slab(uma_keg_t keg, uma_slab_t slab, int start)
844 {
845 	uint8_t *mem;
846 	int i;
847 	uint8_t flags;
848 
849 	CTR4(KTR_UMA, "keg_free_slab keg %s(%p) slab %p, returning %d bytes",
850 	    keg->uk_name, keg, slab, PAGE_SIZE * keg->uk_ppera);
851 
852 	mem = slab->us_data;
853 	flags = slab->us_flags;
854 	i = start;
855 	if (keg->uk_fini != NULL) {
856 		for (i--; i > -1; i--)
857 			keg->uk_fini(slab->us_data + (keg->uk_rsize * i),
858 			    keg->uk_size);
859 	}
860 	if (keg->uk_flags & UMA_ZONE_OFFPAGE)
861 		zone_free_item(keg->uk_slabzone, slab, NULL, SKIP_NONE);
862 	keg->uk_freef(mem, PAGE_SIZE * keg->uk_ppera, flags);
863 	uma_total_dec(PAGE_SIZE * keg->uk_ppera);
864 }
865 
866 /*
867  * Frees pages from a keg back to the system.  This is done on demand from
868  * the pageout daemon.
869  *
870  * Returns nothing.
871  */
872 static void
873 keg_drain(uma_keg_t keg)
874 {
875 	struct slabhead freeslabs = { 0 };
876 	uma_domain_t dom;
877 	uma_slab_t slab, tmp;
878 	int i;
879 
880 	/*
881 	 * We don't want to take pages from statically allocated kegs at this
882 	 * time
883 	 */
884 	if (keg->uk_flags & UMA_ZONE_NOFREE || keg->uk_freef == NULL)
885 		return;
886 
887 	CTR3(KTR_UMA, "keg_drain %s(%p) free items: %u",
888 	    keg->uk_name, keg, keg->uk_free);
889 	KEG_LOCK(keg);
890 	if (keg->uk_free == 0)
891 		goto finished;
892 
893 	for (i = 0; i < vm_ndomains; i++) {
894 		dom = &keg->uk_domain[i];
895 		LIST_FOREACH_SAFE(slab, &dom->ud_free_slab, us_link, tmp) {
896 			/* We have nowhere to free these to. */
897 			if (slab->us_flags & UMA_SLAB_BOOT)
898 				continue;
899 
900 			LIST_REMOVE(slab, us_link);
901 			keg->uk_pages -= keg->uk_ppera;
902 			keg->uk_free -= keg->uk_ipers;
903 
904 			if (keg->uk_flags & UMA_ZONE_HASH)
905 				UMA_HASH_REMOVE(&keg->uk_hash, slab,
906 				    slab->us_data);
907 
908 			SLIST_INSERT_HEAD(&freeslabs, slab, us_hlink);
909 		}
910 	}
911 
912 finished:
913 	KEG_UNLOCK(keg);
914 
915 	while ((slab = SLIST_FIRST(&freeslabs)) != NULL) {
916 		SLIST_REMOVE(&freeslabs, slab, uma_slab, us_hlink);
917 		keg_free_slab(keg, slab, keg->uk_ipers);
918 	}
919 }
920 
921 static void
922 zone_drain_wait(uma_zone_t zone, int waitok)
923 {
924 
925 	/*
926 	 * Set draining to interlock with zone_dtor() so we can release our
927 	 * locks as we go.  Only dtor() should do a WAITOK call since it
928 	 * is the only call that knows the structure will still be available
929 	 * when it wakes up.
930 	 */
931 	ZONE_LOCK(zone);
932 	while (zone->uz_flags & UMA_ZFLAG_DRAINING) {
933 		if (waitok == M_NOWAIT)
934 			goto out;
935 		msleep(zone, zone->uz_lockptr, PVM, "zonedrain", 1);
936 	}
937 	zone->uz_flags |= UMA_ZFLAG_DRAINING;
938 	bucket_cache_drain(zone);
939 	ZONE_UNLOCK(zone);
940 	/*
941 	 * The DRAINING flag protects us from being freed while
942 	 * we're running.  Normally the uma_rwlock would protect us but we
943 	 * must be able to release and acquire the right lock for each keg.
944 	 */
945 	zone_foreach_keg(zone, &keg_drain);
946 	ZONE_LOCK(zone);
947 	zone->uz_flags &= ~UMA_ZFLAG_DRAINING;
948 	wakeup(zone);
949 out:
950 	ZONE_UNLOCK(zone);
951 }
952 
953 void
954 zone_drain(uma_zone_t zone)
955 {
956 
957 	zone_drain_wait(zone, M_NOWAIT);
958 }
959 
960 /*
961  * Allocate a new slab for a keg.  This does not insert the slab onto a list.
962  *
963  * Arguments:
964  *	wait  Shall we wait?
965  *
966  * Returns:
967  *	The slab that was allocated or NULL if there is no memory and the
968  *	caller specified M_NOWAIT.
969  */
970 static uma_slab_t
971 keg_alloc_slab(uma_keg_t keg, uma_zone_t zone, int domain, int wait)
972 {
973 	uma_alloc allocf;
974 	uma_slab_t slab;
975 	unsigned long size;
976 	uint8_t *mem;
977 	uint8_t flags;
978 	int i;
979 
980 	KASSERT(domain >= 0 && domain < vm_ndomains,
981 	    ("keg_alloc_slab: domain %d out of range", domain));
982 	mtx_assert(&keg->uk_lock, MA_OWNED);
983 	slab = NULL;
984 	mem = NULL;
985 
986 	allocf = keg->uk_allocf;
987 	KEG_UNLOCK(keg);
988 	size = keg->uk_ppera * PAGE_SIZE;
989 
990 	if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
991 		slab = zone_alloc_item(keg->uk_slabzone, NULL, domain, wait);
992 		if (slab == NULL)
993 			goto out;
994 	}
995 
996 	/*
997 	 * This reproduces the old vm_zone behavior of zero filling pages the
998 	 * first time they are added to a zone.
999 	 *
1000 	 * Malloced items are zeroed in uma_zalloc.
1001 	 */
1002 
1003 	if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
1004 		wait |= M_ZERO;
1005 	else
1006 		wait &= ~M_ZERO;
1007 
1008 	if (keg->uk_flags & UMA_ZONE_NODUMP)
1009 		wait |= M_NODUMP;
1010 
1011 	/* zone is passed for legacy reasons. */
1012 	mem = allocf(zone, size, domain, &flags, wait);
1013 	if (mem == NULL) {
1014 		if (keg->uk_flags & UMA_ZONE_OFFPAGE)
1015 			zone_free_item(keg->uk_slabzone, slab, NULL, SKIP_NONE);
1016 		slab = NULL;
1017 		goto out;
1018 	}
1019 	uma_total_inc(size);
1020 
1021 	/* Point the slab into the allocated memory */
1022 	if (!(keg->uk_flags & UMA_ZONE_OFFPAGE))
1023 		slab = (uma_slab_t )(mem + keg->uk_pgoff);
1024 
1025 	if (keg->uk_flags & UMA_ZONE_VTOSLAB)
1026 		for (i = 0; i < keg->uk_ppera; i++)
1027 			vsetslab((vm_offset_t)mem + (i * PAGE_SIZE), slab);
1028 
1029 	slab->us_keg = keg;
1030 	slab->us_data = mem;
1031 	slab->us_freecount = keg->uk_ipers;
1032 	slab->us_flags = flags;
1033 	slab->us_domain = domain;
1034 	BIT_FILL(SLAB_SETSIZE, &slab->us_free);
1035 #ifdef INVARIANTS
1036 	BIT_ZERO(SLAB_SETSIZE, &slab->us_debugfree);
1037 #endif
1038 
1039 	if (keg->uk_init != NULL) {
1040 		for (i = 0; i < keg->uk_ipers; i++)
1041 			if (keg->uk_init(slab->us_data + (keg->uk_rsize * i),
1042 			    keg->uk_size, wait) != 0)
1043 				break;
1044 		if (i != keg->uk_ipers) {
1045 			keg_free_slab(keg, slab, i);
1046 			slab = NULL;
1047 			goto out;
1048 		}
1049 	}
1050 out:
1051 	KEG_LOCK(keg);
1052 
1053 	CTR3(KTR_UMA, "keg_alloc_slab: allocated slab %p for %s(%p)",
1054 	    slab, keg->uk_name, keg);
1055 
1056 	if (slab != NULL) {
1057 		if (keg->uk_flags & UMA_ZONE_HASH)
1058 			UMA_HASH_INSERT(&keg->uk_hash, slab, mem);
1059 
1060 		keg->uk_pages += keg->uk_ppera;
1061 		keg->uk_free += keg->uk_ipers;
1062 	}
1063 
1064 	return (slab);
1065 }
1066 
1067 /*
1068  * This function is intended to be used early on in place of page_alloc() so
1069  * that we may use the boot time page cache to satisfy allocations before
1070  * the VM is ready.
1071  */
1072 static void *
1073 startup_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
1074     int wait)
1075 {
1076 	uma_keg_t keg;
1077 	void *mem;
1078 	int pages;
1079 
1080 	keg = zone_first_keg(zone);
1081 
1082 	/*
1083 	 * If we are in BOOT_BUCKETS or higher, than switch to real
1084 	 * allocator.  Zones with page sized slabs switch at BOOT_PAGEALLOC.
1085 	 */
1086 	switch (booted) {
1087 		case BOOT_COLD:
1088 		case BOOT_STRAPPED:
1089 			break;
1090 		case BOOT_PAGEALLOC:
1091 			if (keg->uk_ppera > 1)
1092 				break;
1093 		case BOOT_BUCKETS:
1094 		case BOOT_RUNNING:
1095 #ifdef UMA_MD_SMALL_ALLOC
1096 			keg->uk_allocf = (keg->uk_ppera > 1) ?
1097 			    page_alloc : uma_small_alloc;
1098 #else
1099 			keg->uk_allocf = page_alloc;
1100 #endif
1101 			return keg->uk_allocf(zone, bytes, domain, pflag, wait);
1102 	}
1103 
1104 	/*
1105 	 * Check our small startup cache to see if it has pages remaining.
1106 	 */
1107 	pages = howmany(bytes, PAGE_SIZE);
1108 	KASSERT(pages > 0, ("%s can't reserve 0 pages", __func__));
1109 	if (pages > boot_pages)
1110 		panic("UMA zone \"%s\": Increase vm.boot_pages", zone->uz_name);
1111 #ifdef DIAGNOSTIC
1112 	printf("%s from \"%s\", %d boot pages left\n", __func__, zone->uz_name,
1113 	    boot_pages);
1114 #endif
1115 	mem = bootmem;
1116 	boot_pages -= pages;
1117 	bootmem += pages * PAGE_SIZE;
1118 	*pflag = UMA_SLAB_BOOT;
1119 
1120 	return (mem);
1121 }
1122 
1123 /*
1124  * Allocates a number of pages from the system
1125  *
1126  * Arguments:
1127  *	bytes  The number of bytes requested
1128  *	wait  Shall we wait?
1129  *
1130  * Returns:
1131  *	A pointer to the alloced memory or possibly
1132  *	NULL if M_NOWAIT is set.
1133  */
1134 static void *
1135 page_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
1136     int wait)
1137 {
1138 	void *p;	/* Returned page */
1139 
1140 	*pflag = UMA_SLAB_KERNEL;
1141 	p = (void *) kmem_malloc_domain(domain, bytes, wait);
1142 
1143 	return (p);
1144 }
1145 
1146 /*
1147  * Allocates a number of pages from within an object
1148  *
1149  * Arguments:
1150  *	bytes  The number of bytes requested
1151  *	wait   Shall we wait?
1152  *
1153  * Returns:
1154  *	A pointer to the alloced memory or possibly
1155  *	NULL if M_NOWAIT is set.
1156  */
1157 static void *
1158 noobj_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *flags,
1159     int wait)
1160 {
1161 	TAILQ_HEAD(, vm_page) alloctail;
1162 	u_long npages;
1163 	vm_offset_t retkva, zkva;
1164 	vm_page_t p, p_next;
1165 	uma_keg_t keg;
1166 
1167 	TAILQ_INIT(&alloctail);
1168 	keg = zone_first_keg(zone);
1169 
1170 	npages = howmany(bytes, PAGE_SIZE);
1171 	while (npages > 0) {
1172 		p = vm_page_alloc_domain(NULL, 0, domain, VM_ALLOC_INTERRUPT |
1173 		    VM_ALLOC_WIRED | VM_ALLOC_NOOBJ |
1174 		    ((wait & M_WAITOK) != 0 ? VM_ALLOC_WAITOK :
1175 		    VM_ALLOC_NOWAIT));
1176 		if (p != NULL) {
1177 			/*
1178 			 * Since the page does not belong to an object, its
1179 			 * listq is unused.
1180 			 */
1181 			TAILQ_INSERT_TAIL(&alloctail, p, listq);
1182 			npages--;
1183 			continue;
1184 		}
1185 		/*
1186 		 * Page allocation failed, free intermediate pages and
1187 		 * exit.
1188 		 */
1189 		TAILQ_FOREACH_SAFE(p, &alloctail, listq, p_next) {
1190 			vm_page_unwire(p, PQ_NONE);
1191 			vm_page_free(p);
1192 		}
1193 		return (NULL);
1194 	}
1195 	*flags = UMA_SLAB_PRIV;
1196 	zkva = keg->uk_kva +
1197 	    atomic_fetchadd_long(&keg->uk_offset, round_page(bytes));
1198 	retkva = zkva;
1199 	TAILQ_FOREACH(p, &alloctail, listq) {
1200 		pmap_qenter(zkva, &p, 1);
1201 		zkva += PAGE_SIZE;
1202 	}
1203 
1204 	return ((void *)retkva);
1205 }
1206 
1207 /*
1208  * Frees a number of pages to the system
1209  *
1210  * Arguments:
1211  *	mem   A pointer to the memory to be freed
1212  *	size  The size of the memory being freed
1213  *	flags The original p->us_flags field
1214  *
1215  * Returns:
1216  *	Nothing
1217  */
1218 static void
1219 page_free(void *mem, vm_size_t size, uint8_t flags)
1220 {
1221 	struct vmem *vmem;
1222 
1223 	if (flags & UMA_SLAB_KERNEL)
1224 		vmem = kernel_arena;
1225 	else
1226 		panic("UMA: page_free used with invalid flags %x", flags);
1227 
1228 	kmem_free(vmem, (vm_offset_t)mem, size);
1229 }
1230 
1231 /*
1232  * Zero fill initializer
1233  *
1234  * Arguments/Returns follow uma_init specifications
1235  */
1236 static int
1237 zero_init(void *mem, int size, int flags)
1238 {
1239 	bzero(mem, size);
1240 	return (0);
1241 }
1242 
1243 /*
1244  * Finish creating a small uma keg.  This calculates ipers, and the keg size.
1245  *
1246  * Arguments
1247  *	keg  The zone we should initialize
1248  *
1249  * Returns
1250  *	Nothing
1251  */
1252 static void
1253 keg_small_init(uma_keg_t keg)
1254 {
1255 	u_int rsize;
1256 	u_int memused;
1257 	u_int wastedspace;
1258 	u_int shsize;
1259 	u_int slabsize;
1260 
1261 	if (keg->uk_flags & UMA_ZONE_PCPU) {
1262 		u_int ncpus = (mp_maxid + 1) ? (mp_maxid + 1) : MAXCPU;
1263 
1264 		slabsize = sizeof(struct pcpu);
1265 		keg->uk_ppera = howmany(ncpus * sizeof(struct pcpu),
1266 		    PAGE_SIZE);
1267 	} else {
1268 		slabsize = UMA_SLAB_SIZE;
1269 		keg->uk_ppera = 1;
1270 	}
1271 
1272 	/*
1273 	 * Calculate the size of each allocation (rsize) according to
1274 	 * alignment.  If the requested size is smaller than we have
1275 	 * allocation bits for we round it up.
1276 	 */
1277 	rsize = keg->uk_size;
1278 	if (rsize < slabsize / SLAB_SETSIZE)
1279 		rsize = slabsize / SLAB_SETSIZE;
1280 	if (rsize & keg->uk_align)
1281 		rsize = (rsize & ~keg->uk_align) + (keg->uk_align + 1);
1282 	keg->uk_rsize = rsize;
1283 
1284 	KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0 ||
1285 	    keg->uk_rsize < sizeof(struct pcpu),
1286 	    ("%s: size %u too large", __func__, keg->uk_rsize));
1287 
1288 	if (keg->uk_flags & UMA_ZONE_OFFPAGE)
1289 		shsize = 0;
1290 	else
1291 		shsize = sizeof(struct uma_slab);
1292 
1293 	if (rsize <= slabsize - shsize)
1294 		keg->uk_ipers = (slabsize - shsize) / rsize;
1295 	else {
1296 		/* Handle special case when we have 1 item per slab, so
1297 		 * alignment requirement can be relaxed. */
1298 		KASSERT(keg->uk_size <= slabsize - shsize,
1299 		    ("%s: size %u greater than slab", __func__, keg->uk_size));
1300 		keg->uk_ipers = 1;
1301 	}
1302 	KASSERT(keg->uk_ipers > 0 && keg->uk_ipers <= SLAB_SETSIZE,
1303 	    ("%s: keg->uk_ipers %u", __func__, keg->uk_ipers));
1304 
1305 	memused = keg->uk_ipers * rsize + shsize;
1306 	wastedspace = slabsize - memused;
1307 
1308 	/*
1309 	 * We can't do OFFPAGE if we're internal or if we've been
1310 	 * asked to not go to the VM for buckets.  If we do this we
1311 	 * may end up going to the VM  for slabs which we do not
1312 	 * want to do if we're UMA_ZFLAG_CACHEONLY as a result
1313 	 * of UMA_ZONE_VM, which clearly forbids it.
1314 	 */
1315 	if ((keg->uk_flags & UMA_ZFLAG_INTERNAL) ||
1316 	    (keg->uk_flags & UMA_ZFLAG_CACHEONLY))
1317 		return;
1318 
1319 	/*
1320 	 * See if using an OFFPAGE slab will limit our waste.  Only do
1321 	 * this if it permits more items per-slab.
1322 	 *
1323 	 * XXX We could try growing slabsize to limit max waste as well.
1324 	 * Historically this was not done because the VM could not
1325 	 * efficiently handle contiguous allocations.
1326 	 */
1327 	if ((wastedspace >= slabsize / UMA_MAX_WASTE) &&
1328 	    (keg->uk_ipers < (slabsize / keg->uk_rsize))) {
1329 		keg->uk_ipers = slabsize / keg->uk_rsize;
1330 		KASSERT(keg->uk_ipers > 0 && keg->uk_ipers <= SLAB_SETSIZE,
1331 		    ("%s: keg->uk_ipers %u", __func__, keg->uk_ipers));
1332 		CTR6(KTR_UMA, "UMA decided we need offpage slab headers for "
1333 		    "keg: %s(%p), calculated wastedspace = %d, "
1334 		    "maximum wasted space allowed = %d, "
1335 		    "calculated ipers = %d, "
1336 		    "new wasted space = %d\n", keg->uk_name, keg, wastedspace,
1337 		    slabsize / UMA_MAX_WASTE, keg->uk_ipers,
1338 		    slabsize - keg->uk_ipers * keg->uk_rsize);
1339 		keg->uk_flags |= UMA_ZONE_OFFPAGE;
1340 	}
1341 
1342 	if ((keg->uk_flags & UMA_ZONE_OFFPAGE) &&
1343 	    (keg->uk_flags & UMA_ZONE_VTOSLAB) == 0)
1344 		keg->uk_flags |= UMA_ZONE_HASH;
1345 }
1346 
1347 /*
1348  * Finish creating a large (> UMA_SLAB_SIZE) uma kegs.  Just give in and do
1349  * OFFPAGE for now.  When I can allow for more dynamic slab sizes this will be
1350  * more complicated.
1351  *
1352  * Arguments
1353  *	keg  The keg we should initialize
1354  *
1355  * Returns
1356  *	Nothing
1357  */
1358 static void
1359 keg_large_init(uma_keg_t keg)
1360 {
1361 	u_int shsize;
1362 
1363 	KASSERT(keg != NULL, ("Keg is null in keg_large_init"));
1364 	KASSERT((keg->uk_flags & UMA_ZFLAG_CACHEONLY) == 0,
1365 	    ("keg_large_init: Cannot large-init a UMA_ZFLAG_CACHEONLY keg"));
1366 	KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0,
1367 	    ("%s: Cannot large-init a UMA_ZONE_PCPU keg", __func__));
1368 
1369 	keg->uk_ppera = howmany(keg->uk_size, PAGE_SIZE);
1370 	keg->uk_ipers = 1;
1371 	keg->uk_rsize = keg->uk_size;
1372 
1373 	/* Check whether we have enough space to not do OFFPAGE. */
1374 	if ((keg->uk_flags & UMA_ZONE_OFFPAGE) == 0) {
1375 		shsize = sizeof(struct uma_slab);
1376 		if (shsize & UMA_ALIGN_PTR)
1377 			shsize = (shsize & ~UMA_ALIGN_PTR) +
1378 			    (UMA_ALIGN_PTR + 1);
1379 
1380 		if (PAGE_SIZE * keg->uk_ppera - keg->uk_rsize < shsize) {
1381 			/*
1382 			 * We can't do OFFPAGE if we're internal, in which case
1383 			 * we need an extra page per allocation to contain the
1384 			 * slab header.
1385 			 */
1386 			if ((keg->uk_flags & UMA_ZFLAG_INTERNAL) == 0)
1387 				keg->uk_flags |= UMA_ZONE_OFFPAGE;
1388 			else
1389 				keg->uk_ppera++;
1390 		}
1391 	}
1392 
1393 	if ((keg->uk_flags & UMA_ZONE_OFFPAGE) &&
1394 	    (keg->uk_flags & UMA_ZONE_VTOSLAB) == 0)
1395 		keg->uk_flags |= UMA_ZONE_HASH;
1396 }
1397 
1398 static void
1399 keg_cachespread_init(uma_keg_t keg)
1400 {
1401 	int alignsize;
1402 	int trailer;
1403 	int pages;
1404 	int rsize;
1405 
1406 	KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0,
1407 	    ("%s: Cannot cachespread-init a UMA_ZONE_PCPU keg", __func__));
1408 
1409 	alignsize = keg->uk_align + 1;
1410 	rsize = keg->uk_size;
1411 	/*
1412 	 * We want one item to start on every align boundary in a page.  To
1413 	 * do this we will span pages.  We will also extend the item by the
1414 	 * size of align if it is an even multiple of align.  Otherwise, it
1415 	 * would fall on the same boundary every time.
1416 	 */
1417 	if (rsize & keg->uk_align)
1418 		rsize = (rsize & ~keg->uk_align) + alignsize;
1419 	if ((rsize & alignsize) == 0)
1420 		rsize += alignsize;
1421 	trailer = rsize - keg->uk_size;
1422 	pages = (rsize * (PAGE_SIZE / alignsize)) / PAGE_SIZE;
1423 	pages = MIN(pages, (128 * 1024) / PAGE_SIZE);
1424 	keg->uk_rsize = rsize;
1425 	keg->uk_ppera = pages;
1426 	keg->uk_ipers = ((pages * PAGE_SIZE) + trailer) / rsize;
1427 	keg->uk_flags |= UMA_ZONE_OFFPAGE | UMA_ZONE_VTOSLAB;
1428 	KASSERT(keg->uk_ipers <= SLAB_SETSIZE,
1429 	    ("%s: keg->uk_ipers too high(%d) increase max_ipers", __func__,
1430 	    keg->uk_ipers));
1431 }
1432 
1433 /*
1434  * Keg header ctor.  This initializes all fields, locks, etc.  And inserts
1435  * the keg onto the global keg list.
1436  *
1437  * Arguments/Returns follow uma_ctor specifications
1438  *	udata  Actually uma_kctor_args
1439  */
1440 static int
1441 keg_ctor(void *mem, int size, void *udata, int flags)
1442 {
1443 	struct uma_kctor_args *arg = udata;
1444 	uma_keg_t keg = mem;
1445 	uma_zone_t zone;
1446 
1447 	bzero(keg, size);
1448 	keg->uk_size = arg->size;
1449 	keg->uk_init = arg->uminit;
1450 	keg->uk_fini = arg->fini;
1451 	keg->uk_align = arg->align;
1452 	keg->uk_cursor = 0;
1453 	keg->uk_free = 0;
1454 	keg->uk_reserve = 0;
1455 	keg->uk_pages = 0;
1456 	keg->uk_flags = arg->flags;
1457 	keg->uk_slabzone = NULL;
1458 
1459 	/*
1460 	 * The master zone is passed to us at keg-creation time.
1461 	 */
1462 	zone = arg->zone;
1463 	keg->uk_name = zone->uz_name;
1464 
1465 	if (arg->flags & UMA_ZONE_VM)
1466 		keg->uk_flags |= UMA_ZFLAG_CACHEONLY;
1467 
1468 	if (arg->flags & UMA_ZONE_ZINIT)
1469 		keg->uk_init = zero_init;
1470 
1471 	if (arg->flags & UMA_ZONE_MALLOC)
1472 		keg->uk_flags |= UMA_ZONE_VTOSLAB;
1473 
1474 	if (arg->flags & UMA_ZONE_PCPU)
1475 #ifdef SMP
1476 		keg->uk_flags |= UMA_ZONE_OFFPAGE;
1477 #else
1478 		keg->uk_flags &= ~UMA_ZONE_PCPU;
1479 #endif
1480 
1481 	if (keg->uk_flags & UMA_ZONE_CACHESPREAD) {
1482 		keg_cachespread_init(keg);
1483 	} else {
1484 		if (keg->uk_size > UMA_SLAB_SPACE)
1485 			keg_large_init(keg);
1486 		else
1487 			keg_small_init(keg);
1488 	}
1489 
1490 	if (keg->uk_flags & UMA_ZONE_OFFPAGE)
1491 		keg->uk_slabzone = slabzone;
1492 
1493 	/*
1494 	 * If we haven't booted yet we need allocations to go through the
1495 	 * startup cache until the vm is ready.
1496 	 */
1497 	if (booted < BOOT_PAGEALLOC)
1498 		keg->uk_allocf = startup_alloc;
1499 #ifdef UMA_MD_SMALL_ALLOC
1500 	else if (keg->uk_ppera == 1)
1501 		keg->uk_allocf = uma_small_alloc;
1502 #endif
1503 	else
1504 		keg->uk_allocf = page_alloc;
1505 #ifdef UMA_MD_SMALL_ALLOC
1506 	if (keg->uk_ppera == 1)
1507 		keg->uk_freef = uma_small_free;
1508 	else
1509 #endif
1510 		keg->uk_freef = page_free;
1511 
1512 	/*
1513 	 * Initialize keg's lock
1514 	 */
1515 	KEG_LOCK_INIT(keg, (arg->flags & UMA_ZONE_MTXCLASS));
1516 
1517 	/*
1518 	 * If we're putting the slab header in the actual page we need to
1519 	 * figure out where in each page it goes.  This calculates a right
1520 	 * justified offset into the memory on an ALIGN_PTR boundary.
1521 	 */
1522 	if (!(keg->uk_flags & UMA_ZONE_OFFPAGE)) {
1523 		u_int totsize;
1524 
1525 		/* Size of the slab struct and free list */
1526 		totsize = sizeof(struct uma_slab);
1527 
1528 		if (totsize & UMA_ALIGN_PTR)
1529 			totsize = (totsize & ~UMA_ALIGN_PTR) +
1530 			    (UMA_ALIGN_PTR + 1);
1531 		keg->uk_pgoff = (PAGE_SIZE * keg->uk_ppera) - totsize;
1532 
1533 		/*
1534 		 * The only way the following is possible is if with our
1535 		 * UMA_ALIGN_PTR adjustments we are now bigger than
1536 		 * UMA_SLAB_SIZE.  I haven't checked whether this is
1537 		 * mathematically possible for all cases, so we make
1538 		 * sure here anyway.
1539 		 */
1540 		totsize = keg->uk_pgoff + sizeof(struct uma_slab);
1541 		if (totsize > PAGE_SIZE * keg->uk_ppera) {
1542 			printf("zone %s ipers %d rsize %d size %d\n",
1543 			    zone->uz_name, keg->uk_ipers, keg->uk_rsize,
1544 			    keg->uk_size);
1545 			panic("UMA slab won't fit.");
1546 		}
1547 	}
1548 
1549 	if (keg->uk_flags & UMA_ZONE_HASH)
1550 		hash_alloc(&keg->uk_hash);
1551 
1552 	CTR5(KTR_UMA, "keg_ctor %p zone %s(%p) out %d free %d\n",
1553 	    keg, zone->uz_name, zone,
1554 	    (keg->uk_pages / keg->uk_ppera) * keg->uk_ipers - keg->uk_free,
1555 	    keg->uk_free);
1556 
1557 	LIST_INSERT_HEAD(&keg->uk_zones, zone, uz_link);
1558 
1559 	rw_wlock(&uma_rwlock);
1560 	LIST_INSERT_HEAD(&uma_kegs, keg, uk_link);
1561 	rw_wunlock(&uma_rwlock);
1562 	return (0);
1563 }
1564 
1565 /*
1566  * Zone header ctor.  This initializes all fields, locks, etc.
1567  *
1568  * Arguments/Returns follow uma_ctor specifications
1569  *	udata  Actually uma_zctor_args
1570  */
1571 static int
1572 zone_ctor(void *mem, int size, void *udata, int flags)
1573 {
1574 	struct uma_zctor_args *arg = udata;
1575 	uma_zone_t zone = mem;
1576 	uma_zone_t z;
1577 	uma_keg_t keg;
1578 
1579 	bzero(zone, size);
1580 	zone->uz_name = arg->name;
1581 	zone->uz_ctor = arg->ctor;
1582 	zone->uz_dtor = arg->dtor;
1583 	zone->uz_slab = zone_fetch_slab;
1584 	zone->uz_init = NULL;
1585 	zone->uz_fini = NULL;
1586 	zone->uz_allocs = 0;
1587 	zone->uz_frees = 0;
1588 	zone->uz_fails = 0;
1589 	zone->uz_sleeps = 0;
1590 	zone->uz_count = 0;
1591 	zone->uz_count_min = 0;
1592 	zone->uz_flags = 0;
1593 	zone->uz_warning = NULL;
1594 	/* The domain structures follow the cpu structures. */
1595 	zone->uz_domain = (struct uma_zone_domain *)&zone->uz_cpu[mp_ncpus];
1596 	timevalclear(&zone->uz_ratecheck);
1597 	keg = arg->keg;
1598 
1599 	ZONE_LOCK_INIT(zone, (arg->flags & UMA_ZONE_MTXCLASS));
1600 
1601 	/*
1602 	 * This is a pure cache zone, no kegs.
1603 	 */
1604 	if (arg->import) {
1605 		if (arg->flags & UMA_ZONE_VM)
1606 			arg->flags |= UMA_ZFLAG_CACHEONLY;
1607 		zone->uz_flags = arg->flags;
1608 		zone->uz_size = arg->size;
1609 		zone->uz_import = arg->import;
1610 		zone->uz_release = arg->release;
1611 		zone->uz_arg = arg->arg;
1612 		zone->uz_lockptr = &zone->uz_lock;
1613 		rw_wlock(&uma_rwlock);
1614 		LIST_INSERT_HEAD(&uma_cachezones, zone, uz_link);
1615 		rw_wunlock(&uma_rwlock);
1616 		goto out;
1617 	}
1618 
1619 	/*
1620 	 * Use the regular zone/keg/slab allocator.
1621 	 */
1622 	zone->uz_import = (uma_import)zone_import;
1623 	zone->uz_release = (uma_release)zone_release;
1624 	zone->uz_arg = zone;
1625 
1626 	if (arg->flags & UMA_ZONE_SECONDARY) {
1627 		KASSERT(arg->keg != NULL, ("Secondary zone on zero'd keg"));
1628 		zone->uz_init = arg->uminit;
1629 		zone->uz_fini = arg->fini;
1630 		zone->uz_lockptr = &keg->uk_lock;
1631 		zone->uz_flags |= UMA_ZONE_SECONDARY;
1632 		rw_wlock(&uma_rwlock);
1633 		ZONE_LOCK(zone);
1634 		LIST_FOREACH(z, &keg->uk_zones, uz_link) {
1635 			if (LIST_NEXT(z, uz_link) == NULL) {
1636 				LIST_INSERT_AFTER(z, zone, uz_link);
1637 				break;
1638 			}
1639 		}
1640 		ZONE_UNLOCK(zone);
1641 		rw_wunlock(&uma_rwlock);
1642 	} else if (keg == NULL) {
1643 		if ((keg = uma_kcreate(zone, arg->size, arg->uminit, arg->fini,
1644 		    arg->align, arg->flags)) == NULL)
1645 			return (ENOMEM);
1646 	} else {
1647 		struct uma_kctor_args karg;
1648 		int error;
1649 
1650 		/* We should only be here from uma_startup() */
1651 		karg.size = arg->size;
1652 		karg.uminit = arg->uminit;
1653 		karg.fini = arg->fini;
1654 		karg.align = arg->align;
1655 		karg.flags = arg->flags;
1656 		karg.zone = zone;
1657 		error = keg_ctor(arg->keg, sizeof(struct uma_keg), &karg,
1658 		    flags);
1659 		if (error)
1660 			return (error);
1661 	}
1662 
1663 	/*
1664 	 * Link in the first keg.
1665 	 */
1666 	zone->uz_klink.kl_keg = keg;
1667 	LIST_INSERT_HEAD(&zone->uz_kegs, &zone->uz_klink, kl_link);
1668 	zone->uz_lockptr = &keg->uk_lock;
1669 	zone->uz_size = keg->uk_size;
1670 	zone->uz_flags |= (keg->uk_flags &
1671 	    (UMA_ZONE_INHERIT | UMA_ZFLAG_INHERIT));
1672 
1673 	/*
1674 	 * Some internal zones don't have room allocated for the per cpu
1675 	 * caches.  If we're internal, bail out here.
1676 	 */
1677 	if (keg->uk_flags & UMA_ZFLAG_INTERNAL) {
1678 		KASSERT((zone->uz_flags & UMA_ZONE_SECONDARY) == 0,
1679 		    ("Secondary zone requested UMA_ZFLAG_INTERNAL"));
1680 		return (0);
1681 	}
1682 
1683 out:
1684 	if ((arg->flags & UMA_ZONE_MAXBUCKET) == 0)
1685 		zone->uz_count = bucket_select(zone->uz_size);
1686 	else
1687 		zone->uz_count = BUCKET_MAX;
1688 	zone->uz_count_min = zone->uz_count;
1689 
1690 	return (0);
1691 }
1692 
1693 /*
1694  * Keg header dtor.  This frees all data, destroys locks, frees the hash
1695  * table and removes the keg from the global list.
1696  *
1697  * Arguments/Returns follow uma_dtor specifications
1698  *	udata  unused
1699  */
1700 static void
1701 keg_dtor(void *arg, int size, void *udata)
1702 {
1703 	uma_keg_t keg;
1704 
1705 	keg = (uma_keg_t)arg;
1706 	KEG_LOCK(keg);
1707 	if (keg->uk_free != 0) {
1708 		printf("Freed UMA keg (%s) was not empty (%d items). "
1709 		    " Lost %d pages of memory.\n",
1710 		    keg->uk_name ? keg->uk_name : "",
1711 		    keg->uk_free, keg->uk_pages);
1712 	}
1713 	KEG_UNLOCK(keg);
1714 
1715 	hash_free(&keg->uk_hash);
1716 
1717 	KEG_LOCK_FINI(keg);
1718 }
1719 
1720 /*
1721  * Zone header dtor.
1722  *
1723  * Arguments/Returns follow uma_dtor specifications
1724  *	udata  unused
1725  */
1726 static void
1727 zone_dtor(void *arg, int size, void *udata)
1728 {
1729 	uma_klink_t klink;
1730 	uma_zone_t zone;
1731 	uma_keg_t keg;
1732 
1733 	zone = (uma_zone_t)arg;
1734 	keg = zone_first_keg(zone);
1735 
1736 	if (!(zone->uz_flags & UMA_ZFLAG_INTERNAL))
1737 		cache_drain(zone);
1738 
1739 	rw_wlock(&uma_rwlock);
1740 	LIST_REMOVE(zone, uz_link);
1741 	rw_wunlock(&uma_rwlock);
1742 	/*
1743 	 * XXX there are some races here where
1744 	 * the zone can be drained but zone lock
1745 	 * released and then refilled before we
1746 	 * remove it... we dont care for now
1747 	 */
1748 	zone_drain_wait(zone, M_WAITOK);
1749 	/*
1750 	 * Unlink all of our kegs.
1751 	 */
1752 	while ((klink = LIST_FIRST(&zone->uz_kegs)) != NULL) {
1753 		klink->kl_keg = NULL;
1754 		LIST_REMOVE(klink, kl_link);
1755 		if (klink == &zone->uz_klink)
1756 			continue;
1757 		free(klink, M_TEMP);
1758 	}
1759 	/*
1760 	 * We only destroy kegs from non secondary zones.
1761 	 */
1762 	if (keg != NULL && (zone->uz_flags & UMA_ZONE_SECONDARY) == 0)  {
1763 		rw_wlock(&uma_rwlock);
1764 		LIST_REMOVE(keg, uk_link);
1765 		rw_wunlock(&uma_rwlock);
1766 		zone_free_item(kegs, keg, NULL, SKIP_NONE);
1767 	}
1768 	ZONE_LOCK_FINI(zone);
1769 }
1770 
1771 /*
1772  * Traverses every zone in the system and calls a callback
1773  *
1774  * Arguments:
1775  *	zfunc  A pointer to a function which accepts a zone
1776  *		as an argument.
1777  *
1778  * Returns:
1779  *	Nothing
1780  */
1781 static void
1782 zone_foreach(void (*zfunc)(uma_zone_t))
1783 {
1784 	uma_keg_t keg;
1785 	uma_zone_t zone;
1786 
1787 	rw_rlock(&uma_rwlock);
1788 	LIST_FOREACH(keg, &uma_kegs, uk_link) {
1789 		LIST_FOREACH(zone, &keg->uk_zones, uz_link)
1790 			zfunc(zone);
1791 	}
1792 	rw_runlock(&uma_rwlock);
1793 }
1794 
1795 /*
1796  * Count how many pages do we need to bootstrap.  VM supplies
1797  * its need in early zones in the argument, we add up our zones,
1798  * which consist of: UMA Slabs, UMA Hash and 9 Bucket zones. The
1799  * zone of zones and zone of kegs are accounted separately.
1800  */
1801 #define	UMA_BOOT_ZONES	11
1802 /* Zone of zones and zone of kegs have arbitrary alignment. */
1803 #define	UMA_BOOT_ALIGN	32
1804 static int zsize, ksize;
1805 int
1806 uma_startup_count(int vm_zones)
1807 {
1808 	int zones, pages;
1809 
1810 	ksize = sizeof(struct uma_keg) +
1811 	    (sizeof(struct uma_domain) * vm_ndomains);
1812 	zsize = sizeof(struct uma_zone) +
1813 	    (sizeof(struct uma_cache) * (mp_maxid + 1)) +
1814 	    (sizeof(struct uma_zone_domain) * vm_ndomains);
1815 
1816 	/*
1817 	 * Memory for the zone of kegs and its keg,
1818 	 * and for zone of zones.
1819 	 */
1820 	pages = howmany(roundup(zsize, CACHE_LINE_SIZE) * 2 +
1821 	    roundup(ksize, CACHE_LINE_SIZE), PAGE_SIZE);
1822 
1823 #ifdef	UMA_MD_SMALL_ALLOC
1824 	zones = UMA_BOOT_ZONES;
1825 #else
1826 	zones = UMA_BOOT_ZONES + vm_zones;
1827 	vm_zones = 0;
1828 #endif
1829 
1830 	/* Memory for the rest of startup zones, UMA and VM, ... */
1831 	if (zsize > UMA_SLAB_SPACE)
1832 		pages += (zones + vm_zones) *
1833 		    howmany(roundup2(zsize, UMA_BOOT_ALIGN), UMA_SLAB_SIZE);
1834 	else if (roundup2(zsize, UMA_BOOT_ALIGN) > UMA_SLAB_SPACE)
1835 		pages += zones;
1836 	else
1837 		pages += howmany(zones,
1838 		    UMA_SLAB_SPACE / roundup2(zsize, UMA_BOOT_ALIGN));
1839 
1840 	/* ... and their kegs. Note that zone of zones allocates a keg! */
1841 	pages += howmany(zones + 1,
1842 	    UMA_SLAB_SPACE / roundup2(ksize, UMA_BOOT_ALIGN));
1843 
1844 	/*
1845 	 * Most of startup zones are not going to be offpages, that's
1846 	 * why we use UMA_SLAB_SPACE instead of UMA_SLAB_SIZE in all
1847 	 * calculations.  Some large bucket zones will be offpage, and
1848 	 * thus will allocate hashes.  We take conservative approach
1849 	 * and assume that all zones may allocate hash.  This may give
1850 	 * us some positive inaccuracy, usually an extra single page.
1851 	 */
1852 	pages += howmany(zones, UMA_SLAB_SPACE /
1853 	    (sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT));
1854 
1855 	return (pages);
1856 }
1857 
1858 void
1859 uma_startup(void *mem, int npages)
1860 {
1861 	struct uma_zctor_args args;
1862 	uma_keg_t masterkeg;
1863 	uintptr_t m;
1864 
1865 #ifdef DIAGNOSTIC
1866 	printf("Entering %s with %d boot pages configured\n", __func__, npages);
1867 #endif
1868 
1869 	rw_init(&uma_rwlock, "UMA lock");
1870 
1871 	/* Use bootpages memory for the zone of zones and zone of kegs. */
1872 	m = (uintptr_t)mem;
1873 	zones = (uma_zone_t)m;
1874 	m += roundup(zsize, CACHE_LINE_SIZE);
1875 	kegs = (uma_zone_t)m;
1876 	m += roundup(zsize, CACHE_LINE_SIZE);
1877 	masterkeg = (uma_keg_t)m;
1878 	m += roundup(ksize, CACHE_LINE_SIZE);
1879 	m = roundup(m, PAGE_SIZE);
1880 	npages -= (m - (uintptr_t)mem) / PAGE_SIZE;
1881 	mem = (void *)m;
1882 
1883 	/* "manually" create the initial zone */
1884 	memset(&args, 0, sizeof(args));
1885 	args.name = "UMA Kegs";
1886 	args.size = ksize;
1887 	args.ctor = keg_ctor;
1888 	args.dtor = keg_dtor;
1889 	args.uminit = zero_init;
1890 	args.fini = NULL;
1891 	args.keg = masterkeg;
1892 	args.align = UMA_BOOT_ALIGN - 1;
1893 	args.flags = UMA_ZFLAG_INTERNAL;
1894 	zone_ctor(kegs, zsize, &args, M_WAITOK);
1895 
1896 	bootmem = mem;
1897 	boot_pages = npages;
1898 
1899 	args.name = "UMA Zones";
1900 	args.size = zsize;
1901 	args.ctor = zone_ctor;
1902 	args.dtor = zone_dtor;
1903 	args.uminit = zero_init;
1904 	args.fini = NULL;
1905 	args.keg = NULL;
1906 	args.align = UMA_BOOT_ALIGN - 1;
1907 	args.flags = UMA_ZFLAG_INTERNAL;
1908 	zone_ctor(zones, zsize, &args, M_WAITOK);
1909 
1910 	/* Now make a zone for slab headers */
1911 	slabzone = uma_zcreate("UMA Slabs",
1912 				sizeof(struct uma_slab),
1913 				NULL, NULL, NULL, NULL,
1914 				UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
1915 
1916 	hashzone = uma_zcreate("UMA Hash",
1917 	    sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT,
1918 	    NULL, NULL, NULL, NULL,
1919 	    UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
1920 
1921 	bucket_init();
1922 
1923 	booted = BOOT_STRAPPED;
1924 }
1925 
1926 void
1927 uma_startup1(void)
1928 {
1929 
1930 #ifdef DIAGNOSTIC
1931 	printf("Entering %s with %d boot pages left\n", __func__, boot_pages);
1932 #endif
1933 	booted = BOOT_PAGEALLOC;
1934 }
1935 
1936 void
1937 uma_startup2(void)
1938 {
1939 
1940 #ifdef DIAGNOSTIC
1941 	printf("Entering %s with %d boot pages left\n", __func__, boot_pages);
1942 #endif
1943 	booted = BOOT_BUCKETS;
1944 	sx_init(&uma_drain_lock, "umadrain");
1945 	bucket_enable();
1946 }
1947 
1948 /*
1949  * Initialize our callout handle
1950  *
1951  */
1952 static void
1953 uma_startup3(void)
1954 {
1955 
1956 	booted = BOOT_RUNNING;
1957 	callout_init(&uma_callout, 1);
1958 	callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
1959 }
1960 
1961 static uma_keg_t
1962 uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini,
1963 		int align, uint32_t flags)
1964 {
1965 	struct uma_kctor_args args;
1966 
1967 	args.size = size;
1968 	args.uminit = uminit;
1969 	args.fini = fini;
1970 	args.align = (align == UMA_ALIGN_CACHE) ? uma_align_cache : align;
1971 	args.flags = flags;
1972 	args.zone = zone;
1973 	return (zone_alloc_item(kegs, &args, UMA_ANYDOMAIN, M_WAITOK));
1974 }
1975 
1976 /* Public functions */
1977 /* See uma.h */
1978 void
1979 uma_set_align(int align)
1980 {
1981 
1982 	if (align != UMA_ALIGN_CACHE)
1983 		uma_align_cache = align;
1984 }
1985 
1986 /* See uma.h */
1987 uma_zone_t
1988 uma_zcreate(const char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
1989 		uma_init uminit, uma_fini fini, int align, uint32_t flags)
1990 
1991 {
1992 	struct uma_zctor_args args;
1993 	uma_zone_t res;
1994 	bool locked;
1995 
1996 	KASSERT(powerof2(align + 1), ("invalid zone alignment %d for \"%s\"",
1997 	    align, name));
1998 
1999 	/* This stuff is essential for the zone ctor */
2000 	memset(&args, 0, sizeof(args));
2001 	args.name = name;
2002 	args.size = size;
2003 	args.ctor = ctor;
2004 	args.dtor = dtor;
2005 	args.uminit = uminit;
2006 	args.fini = fini;
2007 #ifdef  INVARIANTS
2008 	/*
2009 	 * If a zone is being created with an empty constructor and
2010 	 * destructor, pass UMA constructor/destructor which checks for
2011 	 * memory use after free.
2012 	 */
2013 	if ((!(flags & (UMA_ZONE_ZINIT | UMA_ZONE_NOFREE))) &&
2014 	    ctor == NULL && dtor == NULL && uminit == NULL && fini == NULL) {
2015 		args.ctor = trash_ctor;
2016 		args.dtor = trash_dtor;
2017 		args.uminit = trash_init;
2018 		args.fini = trash_fini;
2019 	}
2020 #endif
2021 	args.align = align;
2022 	args.flags = flags;
2023 	args.keg = NULL;
2024 
2025 	if (booted < BOOT_BUCKETS) {
2026 		locked = false;
2027 	} else {
2028 		sx_slock(&uma_drain_lock);
2029 		locked = true;
2030 	}
2031 	res = zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK);
2032 	if (locked)
2033 		sx_sunlock(&uma_drain_lock);
2034 	return (res);
2035 }
2036 
2037 /* See uma.h */
2038 uma_zone_t
2039 uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
2040 		    uma_init zinit, uma_fini zfini, uma_zone_t master)
2041 {
2042 	struct uma_zctor_args args;
2043 	uma_keg_t keg;
2044 	uma_zone_t res;
2045 	bool locked;
2046 
2047 	keg = zone_first_keg(master);
2048 	memset(&args, 0, sizeof(args));
2049 	args.name = name;
2050 	args.size = keg->uk_size;
2051 	args.ctor = ctor;
2052 	args.dtor = dtor;
2053 	args.uminit = zinit;
2054 	args.fini = zfini;
2055 	args.align = keg->uk_align;
2056 	args.flags = keg->uk_flags | UMA_ZONE_SECONDARY;
2057 	args.keg = keg;
2058 
2059 	if (booted < BOOT_BUCKETS) {
2060 		locked = false;
2061 	} else {
2062 		sx_slock(&uma_drain_lock);
2063 		locked = true;
2064 	}
2065 	/* XXX Attaches only one keg of potentially many. */
2066 	res = zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK);
2067 	if (locked)
2068 		sx_sunlock(&uma_drain_lock);
2069 	return (res);
2070 }
2071 
2072 /* See uma.h */
2073 uma_zone_t
2074 uma_zcache_create(char *name, int size, uma_ctor ctor, uma_dtor dtor,
2075 		    uma_init zinit, uma_fini zfini, uma_import zimport,
2076 		    uma_release zrelease, void *arg, int flags)
2077 {
2078 	struct uma_zctor_args args;
2079 
2080 	memset(&args, 0, sizeof(args));
2081 	args.name = name;
2082 	args.size = size;
2083 	args.ctor = ctor;
2084 	args.dtor = dtor;
2085 	args.uminit = zinit;
2086 	args.fini = zfini;
2087 	args.import = zimport;
2088 	args.release = zrelease;
2089 	args.arg = arg;
2090 	args.align = 0;
2091 	args.flags = flags;
2092 
2093 	return (zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK));
2094 }
2095 
2096 static void
2097 zone_lock_pair(uma_zone_t a, uma_zone_t b)
2098 {
2099 	if (a < b) {
2100 		ZONE_LOCK(a);
2101 		mtx_lock_flags(b->uz_lockptr, MTX_DUPOK);
2102 	} else {
2103 		ZONE_LOCK(b);
2104 		mtx_lock_flags(a->uz_lockptr, MTX_DUPOK);
2105 	}
2106 }
2107 
2108 static void
2109 zone_unlock_pair(uma_zone_t a, uma_zone_t b)
2110 {
2111 
2112 	ZONE_UNLOCK(a);
2113 	ZONE_UNLOCK(b);
2114 }
2115 
2116 int
2117 uma_zsecond_add(uma_zone_t zone, uma_zone_t master)
2118 {
2119 	uma_klink_t klink;
2120 	uma_klink_t kl;
2121 	int error;
2122 
2123 	error = 0;
2124 	klink = malloc(sizeof(*klink), M_TEMP, M_WAITOK | M_ZERO);
2125 
2126 	zone_lock_pair(zone, master);
2127 	/*
2128 	 * zone must use vtoslab() to resolve objects and must already be
2129 	 * a secondary.
2130 	 */
2131 	if ((zone->uz_flags & (UMA_ZONE_VTOSLAB | UMA_ZONE_SECONDARY))
2132 	    != (UMA_ZONE_VTOSLAB | UMA_ZONE_SECONDARY)) {
2133 		error = EINVAL;
2134 		goto out;
2135 	}
2136 	/*
2137 	 * The new master must also use vtoslab().
2138 	 */
2139 	if ((zone->uz_flags & UMA_ZONE_VTOSLAB) != UMA_ZONE_VTOSLAB) {
2140 		error = EINVAL;
2141 		goto out;
2142 	}
2143 
2144 	/*
2145 	 * The underlying object must be the same size.  rsize
2146 	 * may be different.
2147 	 */
2148 	if (master->uz_size != zone->uz_size) {
2149 		error = E2BIG;
2150 		goto out;
2151 	}
2152 	/*
2153 	 * Put it at the end of the list.
2154 	 */
2155 	klink->kl_keg = zone_first_keg(master);
2156 	LIST_FOREACH(kl, &zone->uz_kegs, kl_link) {
2157 		if (LIST_NEXT(kl, kl_link) == NULL) {
2158 			LIST_INSERT_AFTER(kl, klink, kl_link);
2159 			break;
2160 		}
2161 	}
2162 	klink = NULL;
2163 	zone->uz_flags |= UMA_ZFLAG_MULTI;
2164 	zone->uz_slab = zone_fetch_slab_multi;
2165 
2166 out:
2167 	zone_unlock_pair(zone, master);
2168 	if (klink != NULL)
2169 		free(klink, M_TEMP);
2170 
2171 	return (error);
2172 }
2173 
2174 
2175 /* See uma.h */
2176 void
2177 uma_zdestroy(uma_zone_t zone)
2178 {
2179 
2180 	sx_slock(&uma_drain_lock);
2181 	zone_free_item(zones, zone, NULL, SKIP_NONE);
2182 	sx_sunlock(&uma_drain_lock);
2183 }
2184 
2185 void
2186 uma_zwait(uma_zone_t zone)
2187 {
2188 	void *item;
2189 
2190 	item = uma_zalloc_arg(zone, NULL, M_WAITOK);
2191 	uma_zfree(zone, item);
2192 }
2193 
2194 /* See uma.h */
2195 void *
2196 uma_zalloc_arg(uma_zone_t zone, void *udata, int flags)
2197 {
2198 	uma_zone_domain_t zdom;
2199 	uma_bucket_t bucket;
2200 	uma_cache_t cache;
2201 	void *item;
2202 	int cpu, domain, lockfail;
2203 
2204 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
2205 	random_harvest_fast_uma(&zone, sizeof(zone), 1, RANDOM_UMA);
2206 
2207 	/* This is the fast path allocation */
2208 	CTR4(KTR_UMA, "uma_zalloc_arg thread %x zone %s(%p) flags %d",
2209 	    curthread, zone->uz_name, zone, flags);
2210 
2211 	if (flags & M_WAITOK) {
2212 		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
2213 		    "uma_zalloc_arg: zone \"%s\"", zone->uz_name);
2214 	}
2215 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
2216 	    ("uma_zalloc_arg: called with spinlock or critical section held"));
2217 
2218 #ifdef DEBUG_MEMGUARD
2219 	if (memguard_cmp_zone(zone)) {
2220 		item = memguard_alloc(zone->uz_size, flags);
2221 		if (item != NULL) {
2222 			if (zone->uz_init != NULL &&
2223 			    zone->uz_init(item, zone->uz_size, flags) != 0)
2224 				return (NULL);
2225 			if (zone->uz_ctor != NULL &&
2226 			    zone->uz_ctor(item, zone->uz_size, udata,
2227 			    flags) != 0) {
2228 			    	zone->uz_fini(item, zone->uz_size);
2229 				return (NULL);
2230 			}
2231 			return (item);
2232 		}
2233 		/* This is unfortunate but should not be fatal. */
2234 	}
2235 #endif
2236 	/*
2237 	 * If possible, allocate from the per-CPU cache.  There are two
2238 	 * requirements for safe access to the per-CPU cache: (1) the thread
2239 	 * accessing the cache must not be preempted or yield during access,
2240 	 * and (2) the thread must not migrate CPUs without switching which
2241 	 * cache it accesses.  We rely on a critical section to prevent
2242 	 * preemption and migration.  We release the critical section in
2243 	 * order to acquire the zone mutex if we are unable to allocate from
2244 	 * the current cache; when we re-acquire the critical section, we
2245 	 * must detect and handle migration if it has occurred.
2246 	 */
2247 	critical_enter();
2248 	cpu = curcpu;
2249 	cache = &zone->uz_cpu[cpu];
2250 
2251 zalloc_start:
2252 	bucket = cache->uc_allocbucket;
2253 	if (bucket != NULL && bucket->ub_cnt > 0) {
2254 		bucket->ub_cnt--;
2255 		item = bucket->ub_bucket[bucket->ub_cnt];
2256 #ifdef INVARIANTS
2257 		bucket->ub_bucket[bucket->ub_cnt] = NULL;
2258 #endif
2259 		KASSERT(item != NULL, ("uma_zalloc: Bucket pointer mangled."));
2260 		cache->uc_allocs++;
2261 		critical_exit();
2262 		if (zone->uz_ctor != NULL &&
2263 		    zone->uz_ctor(item, zone->uz_size, udata, flags) != 0) {
2264 			atomic_add_long(&zone->uz_fails, 1);
2265 			zone_free_item(zone, item, udata, SKIP_DTOR);
2266 			return (NULL);
2267 		}
2268 #ifdef INVARIANTS
2269 		uma_dbg_alloc(zone, NULL, item);
2270 #endif
2271 		if (flags & M_ZERO)
2272 			uma_zero_item(item, zone);
2273 		return (item);
2274 	}
2275 
2276 	/*
2277 	 * We have run out of items in our alloc bucket.
2278 	 * See if we can switch with our free bucket.
2279 	 */
2280 	bucket = cache->uc_freebucket;
2281 	if (bucket != NULL && bucket->ub_cnt > 0) {
2282 		CTR2(KTR_UMA,
2283 		    "uma_zalloc: zone %s(%p) swapping empty with alloc",
2284 		    zone->uz_name, zone);
2285 		cache->uc_freebucket = cache->uc_allocbucket;
2286 		cache->uc_allocbucket = bucket;
2287 		goto zalloc_start;
2288 	}
2289 
2290 	/*
2291 	 * Discard any empty allocation bucket while we hold no locks.
2292 	 */
2293 	bucket = cache->uc_allocbucket;
2294 	cache->uc_allocbucket = NULL;
2295 	critical_exit();
2296 	if (bucket != NULL)
2297 		bucket_free(zone, bucket, udata);
2298 
2299 	if (zone->uz_flags & UMA_ZONE_NUMA)
2300 		domain = PCPU_GET(domain);
2301 	else
2302 		domain = UMA_ANYDOMAIN;
2303 
2304 	/* Short-circuit for zones without buckets and low memory. */
2305 	if (zone->uz_count == 0 || bucketdisable)
2306 		goto zalloc_item;
2307 
2308 	/*
2309 	 * Attempt to retrieve the item from the per-CPU cache has failed, so
2310 	 * we must go back to the zone.  This requires the zone lock, so we
2311 	 * must drop the critical section, then re-acquire it when we go back
2312 	 * to the cache.  Since the critical section is released, we may be
2313 	 * preempted or migrate.  As such, make sure not to maintain any
2314 	 * thread-local state specific to the cache from prior to releasing
2315 	 * the critical section.
2316 	 */
2317 	lockfail = 0;
2318 	if (ZONE_TRYLOCK(zone) == 0) {
2319 		/* Record contention to size the buckets. */
2320 		ZONE_LOCK(zone);
2321 		lockfail = 1;
2322 	}
2323 	critical_enter();
2324 	cpu = curcpu;
2325 	cache = &zone->uz_cpu[cpu];
2326 
2327 	/*
2328 	 * Since we have locked the zone we may as well send back our stats.
2329 	 */
2330 	atomic_add_long(&zone->uz_allocs, cache->uc_allocs);
2331 	atomic_add_long(&zone->uz_frees, cache->uc_frees);
2332 	cache->uc_allocs = 0;
2333 	cache->uc_frees = 0;
2334 
2335 	/* See if we lost the race to fill the cache. */
2336 	if (cache->uc_allocbucket != NULL) {
2337 		ZONE_UNLOCK(zone);
2338 		goto zalloc_start;
2339 	}
2340 
2341 	/*
2342 	 * Check the zone's cache of buckets.
2343 	 */
2344 	if (domain == UMA_ANYDOMAIN)
2345 		zdom = &zone->uz_domain[0];
2346 	else
2347 		zdom = &zone->uz_domain[domain];
2348 	if ((bucket = LIST_FIRST(&zdom->uzd_buckets)) != NULL) {
2349 		KASSERT(bucket->ub_cnt != 0,
2350 		    ("uma_zalloc_arg: Returning an empty bucket."));
2351 
2352 		LIST_REMOVE(bucket, ub_link);
2353 		cache->uc_allocbucket = bucket;
2354 		ZONE_UNLOCK(zone);
2355 		goto zalloc_start;
2356 	}
2357 	/* We are no longer associated with this CPU. */
2358 	critical_exit();
2359 
2360 	/*
2361 	 * We bump the uz count when the cache size is insufficient to
2362 	 * handle the working set.
2363 	 */
2364 	if (lockfail && zone->uz_count < BUCKET_MAX)
2365 		zone->uz_count++;
2366 	ZONE_UNLOCK(zone);
2367 
2368 	/*
2369 	 * Now lets just fill a bucket and put it on the free list.  If that
2370 	 * works we'll restart the allocation from the beginning and it
2371 	 * will use the just filled bucket.
2372 	 */
2373 	bucket = zone_alloc_bucket(zone, udata, domain, flags);
2374 	CTR3(KTR_UMA, "uma_zalloc: zone %s(%p) bucket zone returned %p",
2375 	    zone->uz_name, zone, bucket);
2376 	if (bucket != NULL) {
2377 		ZONE_LOCK(zone);
2378 		critical_enter();
2379 		cpu = curcpu;
2380 		cache = &zone->uz_cpu[cpu];
2381 		/*
2382 		 * See if we lost the race or were migrated.  Cache the
2383 		 * initialized bucket to make this less likely or claim
2384 		 * the memory directly.
2385 		 */
2386 		if (cache->uc_allocbucket != NULL ||
2387 		    (zone->uz_flags & UMA_ZONE_NUMA &&
2388 		    domain != PCPU_GET(domain)))
2389 			LIST_INSERT_HEAD(&zdom->uzd_buckets, bucket, ub_link);
2390 		else
2391 			cache->uc_allocbucket = bucket;
2392 		ZONE_UNLOCK(zone);
2393 		goto zalloc_start;
2394 	}
2395 
2396 	/*
2397 	 * We may not be able to get a bucket so return an actual item.
2398 	 */
2399 zalloc_item:
2400 	item = zone_alloc_item(zone, udata, domain, flags);
2401 
2402 	return (item);
2403 }
2404 
2405 void *
2406 uma_zalloc_domain(uma_zone_t zone, void *udata, int domain, int flags)
2407 {
2408 
2409 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
2410 	random_harvest_fast_uma(&zone, sizeof(zone), 1, RANDOM_UMA);
2411 
2412 	/* This is the fast path allocation */
2413 	CTR5(KTR_UMA,
2414 	    "uma_zalloc_domain thread %x zone %s(%p) domain %d flags %d",
2415 	    curthread, zone->uz_name, zone, domain, flags);
2416 
2417 	if (flags & M_WAITOK) {
2418 		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
2419 		    "uma_zalloc_domain: zone \"%s\"", zone->uz_name);
2420 	}
2421 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
2422 	    ("uma_zalloc_domain: called with spinlock or critical section held"));
2423 
2424 	return (zone_alloc_item(zone, udata, domain, flags));
2425 }
2426 
2427 /*
2428  * Find a slab with some space.  Prefer slabs that are partially used over those
2429  * that are totally full.  This helps to reduce fragmentation.
2430  *
2431  * If 'rr' is 1, search all domains starting from 'domain'.  Otherwise check
2432  * only 'domain'.
2433  */
2434 static uma_slab_t
2435 keg_first_slab(uma_keg_t keg, int domain, int rr)
2436 {
2437 	uma_domain_t dom;
2438 	uma_slab_t slab;
2439 	int start;
2440 
2441 	KASSERT(domain >= 0 && domain < vm_ndomains,
2442 	    ("keg_first_slab: domain %d out of range", domain));
2443 
2444 	slab = NULL;
2445 	start = domain;
2446 	do {
2447 		dom = &keg->uk_domain[domain];
2448 		if (!LIST_EMPTY(&dom->ud_part_slab))
2449 			return (LIST_FIRST(&dom->ud_part_slab));
2450 		if (!LIST_EMPTY(&dom->ud_free_slab)) {
2451 			slab = LIST_FIRST(&dom->ud_free_slab);
2452 			LIST_REMOVE(slab, us_link);
2453 			LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
2454 			return (slab);
2455 		}
2456 		if (rr)
2457 			domain = (domain + 1) % vm_ndomains;
2458 	} while (domain != start);
2459 
2460 	return (NULL);
2461 }
2462 
2463 static uma_slab_t
2464 keg_fetch_slab(uma_keg_t keg, uma_zone_t zone, int rdomain, int flags)
2465 {
2466 	uma_domain_t dom;
2467 	uma_slab_t slab;
2468 	int allocflags, domain, reserve, rr, start;
2469 
2470 	mtx_assert(&keg->uk_lock, MA_OWNED);
2471 	slab = NULL;
2472 	reserve = 0;
2473 	allocflags = flags;
2474 	if ((flags & M_USE_RESERVE) == 0)
2475 		reserve = keg->uk_reserve;
2476 
2477 	/*
2478 	 * Round-robin for non first-touch zones when there is more than one
2479 	 * domain.
2480 	 */
2481 	if (vm_ndomains == 1)
2482 		rdomain = 0;
2483 	rr = rdomain == UMA_ANYDOMAIN;
2484 	if (rr) {
2485 		keg->uk_cursor = (keg->uk_cursor + 1) % vm_ndomains;
2486 		domain = start = keg->uk_cursor;
2487 		/* Only block on the second pass. */
2488 		if ((flags & (M_WAITOK | M_NOVM)) == M_WAITOK)
2489 			allocflags = (allocflags & ~M_WAITOK) | M_NOWAIT;
2490 	} else
2491 		domain = start = rdomain;
2492 
2493 again:
2494 	do {
2495 		if (keg->uk_free > reserve &&
2496 		    (slab = keg_first_slab(keg, domain, rr)) != NULL) {
2497 			MPASS(slab->us_keg == keg);
2498 			return (slab);
2499 		}
2500 
2501 		/*
2502 		 * M_NOVM means don't ask at all!
2503 		 */
2504 		if (flags & M_NOVM)
2505 			break;
2506 
2507 		if (keg->uk_maxpages && keg->uk_pages >= keg->uk_maxpages) {
2508 			keg->uk_flags |= UMA_ZFLAG_FULL;
2509 			/*
2510 			 * If this is not a multi-zone, set the FULL bit.
2511 			 * Otherwise slab_multi() takes care of it.
2512 			 */
2513 			if ((zone->uz_flags & UMA_ZFLAG_MULTI) == 0) {
2514 				zone->uz_flags |= UMA_ZFLAG_FULL;
2515 				zone_log_warning(zone);
2516 				zone_maxaction(zone);
2517 			}
2518 			if (flags & M_NOWAIT)
2519 				return (NULL);
2520 			zone->uz_sleeps++;
2521 			msleep(keg, &keg->uk_lock, PVM, "keglimit", 0);
2522 			continue;
2523 		}
2524 		slab = keg_alloc_slab(keg, zone, domain, allocflags);
2525 		/*
2526 		 * If we got a slab here it's safe to mark it partially used
2527 		 * and return.  We assume that the caller is going to remove
2528 		 * at least one item.
2529 		 */
2530 		if (slab) {
2531 			MPASS(slab->us_keg == keg);
2532 			dom = &keg->uk_domain[slab->us_domain];
2533 			LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
2534 			return (slab);
2535 		}
2536 		if (rr) {
2537 			keg->uk_cursor = (keg->uk_cursor + 1) % vm_ndomains;
2538 			domain = keg->uk_cursor;
2539 		}
2540 	} while (domain != start);
2541 
2542 	/* Retry domain scan with blocking. */
2543 	if (allocflags != flags) {
2544 		allocflags = flags;
2545 		goto again;
2546 	}
2547 
2548 	/*
2549 	 * We might not have been able to get a slab but another cpu
2550 	 * could have while we were unlocked.  Check again before we
2551 	 * fail.
2552 	 */
2553 	if (keg->uk_free > reserve &&
2554 	    (slab = keg_first_slab(keg, domain, rr)) != NULL) {
2555 		MPASS(slab->us_keg == keg);
2556 		return (slab);
2557 	}
2558 	return (NULL);
2559 }
2560 
2561 static uma_slab_t
2562 zone_fetch_slab(uma_zone_t zone, uma_keg_t keg, int domain, int flags)
2563 {
2564 	uma_slab_t slab;
2565 
2566 	if (keg == NULL) {
2567 		keg = zone_first_keg(zone);
2568 		KEG_LOCK(keg);
2569 	}
2570 
2571 	for (;;) {
2572 		slab = keg_fetch_slab(keg, zone, domain, flags);
2573 		if (slab)
2574 			return (slab);
2575 		if (flags & (M_NOWAIT | M_NOVM))
2576 			break;
2577 	}
2578 	KEG_UNLOCK(keg);
2579 	return (NULL);
2580 }
2581 
2582 /*
2583  * uma_zone_fetch_slab_multi:  Fetches a slab from one available keg.  Returns
2584  * with the keg locked.  On NULL no lock is held.
2585  *
2586  * The last pointer is used to seed the search.  It is not required.
2587  */
2588 static uma_slab_t
2589 zone_fetch_slab_multi(uma_zone_t zone, uma_keg_t last, int domain, int rflags)
2590 {
2591 	uma_klink_t klink;
2592 	uma_slab_t slab;
2593 	uma_keg_t keg;
2594 	int flags;
2595 	int empty;
2596 	int full;
2597 
2598 	/*
2599 	 * Don't wait on the first pass.  This will skip limit tests
2600 	 * as well.  We don't want to block if we can find a provider
2601 	 * without blocking.
2602 	 */
2603 	flags = (rflags & ~M_WAITOK) | M_NOWAIT;
2604 	/*
2605 	 * Use the last slab allocated as a hint for where to start
2606 	 * the search.
2607 	 */
2608 	if (last != NULL) {
2609 		slab = keg_fetch_slab(last, zone, domain, flags);
2610 		if (slab)
2611 			return (slab);
2612 		KEG_UNLOCK(last);
2613 	}
2614 	/*
2615 	 * Loop until we have a slab incase of transient failures
2616 	 * while M_WAITOK is specified.  I'm not sure this is 100%
2617 	 * required but we've done it for so long now.
2618 	 */
2619 	for (;;) {
2620 		empty = 0;
2621 		full = 0;
2622 		/*
2623 		 * Search the available kegs for slabs.  Be careful to hold the
2624 		 * correct lock while calling into the keg layer.
2625 		 */
2626 		LIST_FOREACH(klink, &zone->uz_kegs, kl_link) {
2627 			keg = klink->kl_keg;
2628 			KEG_LOCK(keg);
2629 			if ((keg->uk_flags & UMA_ZFLAG_FULL) == 0) {
2630 				slab = keg_fetch_slab(keg, zone, domain, flags);
2631 				if (slab)
2632 					return (slab);
2633 			}
2634 			if (keg->uk_flags & UMA_ZFLAG_FULL)
2635 				full++;
2636 			else
2637 				empty++;
2638 			KEG_UNLOCK(keg);
2639 		}
2640 		if (rflags & (M_NOWAIT | M_NOVM))
2641 			break;
2642 		flags = rflags;
2643 		/*
2644 		 * All kegs are full.  XXX We can't atomically check all kegs
2645 		 * and sleep so just sleep for a short period and retry.
2646 		 */
2647 		if (full && !empty) {
2648 			ZONE_LOCK(zone);
2649 			zone->uz_flags |= UMA_ZFLAG_FULL;
2650 			zone->uz_sleeps++;
2651 			zone_log_warning(zone);
2652 			zone_maxaction(zone);
2653 			msleep(zone, zone->uz_lockptr, PVM,
2654 			    "zonelimit", hz/100);
2655 			zone->uz_flags &= ~UMA_ZFLAG_FULL;
2656 			ZONE_UNLOCK(zone);
2657 			continue;
2658 		}
2659 	}
2660 	return (NULL);
2661 }
2662 
2663 static void *
2664 slab_alloc_item(uma_keg_t keg, uma_slab_t slab)
2665 {
2666 	uma_domain_t dom;
2667 	void *item;
2668 	uint8_t freei;
2669 
2670 	MPASS(keg == slab->us_keg);
2671 	mtx_assert(&keg->uk_lock, MA_OWNED);
2672 
2673 	freei = BIT_FFS(SLAB_SETSIZE, &slab->us_free) - 1;
2674 	BIT_CLR(SLAB_SETSIZE, freei, &slab->us_free);
2675 	item = slab->us_data + (keg->uk_rsize * freei);
2676 	slab->us_freecount--;
2677 	keg->uk_free--;
2678 
2679 	/* Move this slab to the full list */
2680 	if (slab->us_freecount == 0) {
2681 		LIST_REMOVE(slab, us_link);
2682 		dom = &keg->uk_domain[slab->us_domain];
2683 		LIST_INSERT_HEAD(&dom->ud_full_slab, slab, us_link);
2684 	}
2685 
2686 	return (item);
2687 }
2688 
2689 static int
2690 zone_import(uma_zone_t zone, void **bucket, int max, int domain, int flags)
2691 {
2692 	uma_slab_t slab;
2693 	uma_keg_t keg;
2694 	int stripe;
2695 	int i;
2696 
2697 	slab = NULL;
2698 	keg = NULL;
2699 	/* Try to keep the buckets totally full */
2700 	for (i = 0; i < max; ) {
2701 		if ((slab = zone->uz_slab(zone, keg, domain, flags)) == NULL)
2702 			break;
2703 		keg = slab->us_keg;
2704 		stripe = howmany(max, vm_ndomains);
2705 		while (slab->us_freecount && i < max) {
2706 			bucket[i++] = slab_alloc_item(keg, slab);
2707 			if (keg->uk_free <= keg->uk_reserve)
2708 				break;
2709 #ifdef NUMA
2710 			/*
2711 			 * If the zone is striped we pick a new slab for every
2712 			 * N allocations.  Eliminating this conditional will
2713 			 * instead pick a new domain for each bucket rather
2714 			 * than stripe within each bucket.  The current option
2715 			 * produces more fragmentation and requires more cpu
2716 			 * time but yields better distribution.
2717 			 */
2718 			if ((zone->uz_flags & UMA_ZONE_NUMA) == 0 &&
2719 			    vm_ndomains > 1 && --stripe == 0)
2720 				break;
2721 #endif
2722 		}
2723 		/* Don't block if we allocated any successfully. */
2724 		flags &= ~M_WAITOK;
2725 		flags |= M_NOWAIT;
2726 	}
2727 	if (slab != NULL)
2728 		KEG_UNLOCK(keg);
2729 
2730 	return i;
2731 }
2732 
2733 static uma_bucket_t
2734 zone_alloc_bucket(uma_zone_t zone, void *udata, int domain, int flags)
2735 {
2736 	uma_bucket_t bucket;
2737 	int max;
2738 
2739 	/* Don't wait for buckets, preserve caller's NOVM setting. */
2740 	bucket = bucket_alloc(zone, udata, M_NOWAIT | (flags & M_NOVM));
2741 	if (bucket == NULL)
2742 		return (NULL);
2743 
2744 	max = MIN(bucket->ub_entries, zone->uz_count);
2745 	bucket->ub_cnt = zone->uz_import(zone->uz_arg, bucket->ub_bucket,
2746 	    max, domain, flags);
2747 
2748 	/*
2749 	 * Initialize the memory if necessary.
2750 	 */
2751 	if (bucket->ub_cnt != 0 && zone->uz_init != NULL) {
2752 		int i;
2753 
2754 		for (i = 0; i < bucket->ub_cnt; i++)
2755 			if (zone->uz_init(bucket->ub_bucket[i], zone->uz_size,
2756 			    flags) != 0)
2757 				break;
2758 		/*
2759 		 * If we couldn't initialize the whole bucket, put the
2760 		 * rest back onto the freelist.
2761 		 */
2762 		if (i != bucket->ub_cnt) {
2763 			zone->uz_release(zone->uz_arg, &bucket->ub_bucket[i],
2764 			    bucket->ub_cnt - i);
2765 #ifdef INVARIANTS
2766 			bzero(&bucket->ub_bucket[i],
2767 			    sizeof(void *) * (bucket->ub_cnt - i));
2768 #endif
2769 			bucket->ub_cnt = i;
2770 		}
2771 	}
2772 
2773 	if (bucket->ub_cnt == 0) {
2774 		bucket_free(zone, bucket, udata);
2775 		atomic_add_long(&zone->uz_fails, 1);
2776 		return (NULL);
2777 	}
2778 
2779 	return (bucket);
2780 }
2781 
2782 /*
2783  * Allocates a single item from a zone.
2784  *
2785  * Arguments
2786  *	zone   The zone to alloc for.
2787  *	udata  The data to be passed to the constructor.
2788  *	domain The domain to allocate from or UMA_ANYDOMAIN.
2789  *	flags  M_WAITOK, M_NOWAIT, M_ZERO.
2790  *
2791  * Returns
2792  *	NULL if there is no memory and M_NOWAIT is set
2793  *	An item if successful
2794  */
2795 
2796 static void *
2797 zone_alloc_item(uma_zone_t zone, void *udata, int domain, int flags)
2798 {
2799 	void *item;
2800 
2801 	item = NULL;
2802 
2803 	if (zone->uz_import(zone->uz_arg, &item, 1, domain, flags) != 1)
2804 		goto fail;
2805 	atomic_add_long(&zone->uz_allocs, 1);
2806 
2807 	/*
2808 	 * We have to call both the zone's init (not the keg's init)
2809 	 * and the zone's ctor.  This is because the item is going from
2810 	 * a keg slab directly to the user, and the user is expecting it
2811 	 * to be both zone-init'd as well as zone-ctor'd.
2812 	 */
2813 	if (zone->uz_init != NULL) {
2814 		if (zone->uz_init(item, zone->uz_size, flags) != 0) {
2815 			zone_free_item(zone, item, udata, SKIP_FINI);
2816 			goto fail;
2817 		}
2818 	}
2819 	if (zone->uz_ctor != NULL) {
2820 		if (zone->uz_ctor(item, zone->uz_size, udata, flags) != 0) {
2821 			zone_free_item(zone, item, udata, SKIP_DTOR);
2822 			goto fail;
2823 		}
2824 	}
2825 #ifdef INVARIANTS
2826 	uma_dbg_alloc(zone, NULL, item);
2827 #endif
2828 	if (flags & M_ZERO)
2829 		uma_zero_item(item, zone);
2830 
2831 	CTR3(KTR_UMA, "zone_alloc_item item %p from %s(%p)", item,
2832 	    zone->uz_name, zone);
2833 
2834 	return (item);
2835 
2836 fail:
2837 	CTR2(KTR_UMA, "zone_alloc_item failed from %s(%p)",
2838 	    zone->uz_name, zone);
2839 	atomic_add_long(&zone->uz_fails, 1);
2840 	return (NULL);
2841 }
2842 
2843 /* See uma.h */
2844 void
2845 uma_zfree_arg(uma_zone_t zone, void *item, void *udata)
2846 {
2847 	uma_cache_t cache;
2848 	uma_bucket_t bucket;
2849 	uma_zone_domain_t zdom;
2850 	int cpu, domain, lockfail;
2851 
2852 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
2853 	random_harvest_fast_uma(&zone, sizeof(zone), 1, RANDOM_UMA);
2854 
2855 	CTR2(KTR_UMA, "uma_zfree_arg thread %x zone %s", curthread,
2856 	    zone->uz_name);
2857 
2858 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
2859 	    ("uma_zfree_arg: called with spinlock or critical section held"));
2860 
2861         /* uma_zfree(..., NULL) does nothing, to match free(9). */
2862         if (item == NULL)
2863                 return;
2864 #ifdef DEBUG_MEMGUARD
2865 	if (is_memguard_addr(item)) {
2866 		if (zone->uz_dtor != NULL)
2867 			zone->uz_dtor(item, zone->uz_size, udata);
2868 		if (zone->uz_fini != NULL)
2869 			zone->uz_fini(item, zone->uz_size);
2870 		memguard_free(item);
2871 		return;
2872 	}
2873 #endif
2874 #ifdef INVARIANTS
2875 	if (zone->uz_flags & UMA_ZONE_MALLOC)
2876 		uma_dbg_free(zone, udata, item);
2877 	else
2878 		uma_dbg_free(zone, NULL, item);
2879 #endif
2880 	if (zone->uz_dtor != NULL)
2881 		zone->uz_dtor(item, zone->uz_size, udata);
2882 
2883 	/*
2884 	 * The race here is acceptable.  If we miss it we'll just have to wait
2885 	 * a little longer for the limits to be reset.
2886 	 */
2887 	if (zone->uz_flags & UMA_ZFLAG_FULL)
2888 		goto zfree_item;
2889 
2890 	/*
2891 	 * If possible, free to the per-CPU cache.  There are two
2892 	 * requirements for safe access to the per-CPU cache: (1) the thread
2893 	 * accessing the cache must not be preempted or yield during access,
2894 	 * and (2) the thread must not migrate CPUs without switching which
2895 	 * cache it accesses.  We rely on a critical section to prevent
2896 	 * preemption and migration.  We release the critical section in
2897 	 * order to acquire the zone mutex if we are unable to free to the
2898 	 * current cache; when we re-acquire the critical section, we must
2899 	 * detect and handle migration if it has occurred.
2900 	 */
2901 zfree_restart:
2902 	critical_enter();
2903 	cpu = curcpu;
2904 	cache = &zone->uz_cpu[cpu];
2905 
2906 zfree_start:
2907 	/*
2908 	 * Try to free into the allocbucket first to give LIFO ordering
2909 	 * for cache-hot datastructures.  Spill over into the freebucket
2910 	 * if necessary.  Alloc will swap them if one runs dry.
2911 	 */
2912 	bucket = cache->uc_allocbucket;
2913 	if (bucket == NULL || bucket->ub_cnt >= bucket->ub_entries)
2914 		bucket = cache->uc_freebucket;
2915 	if (bucket != NULL && bucket->ub_cnt < bucket->ub_entries) {
2916 		KASSERT(bucket->ub_bucket[bucket->ub_cnt] == NULL,
2917 		    ("uma_zfree: Freeing to non free bucket index."));
2918 		bucket->ub_bucket[bucket->ub_cnt] = item;
2919 		bucket->ub_cnt++;
2920 		cache->uc_frees++;
2921 		critical_exit();
2922 		return;
2923 	}
2924 
2925 	/*
2926 	 * We must go back the zone, which requires acquiring the zone lock,
2927 	 * which in turn means we must release and re-acquire the critical
2928 	 * section.  Since the critical section is released, we may be
2929 	 * preempted or migrate.  As such, make sure not to maintain any
2930 	 * thread-local state specific to the cache from prior to releasing
2931 	 * the critical section.
2932 	 */
2933 	critical_exit();
2934 	if (zone->uz_count == 0 || bucketdisable)
2935 		goto zfree_item;
2936 
2937 	lockfail = 0;
2938 	if (ZONE_TRYLOCK(zone) == 0) {
2939 		/* Record contention to size the buckets. */
2940 		ZONE_LOCK(zone);
2941 		lockfail = 1;
2942 	}
2943 	critical_enter();
2944 	cpu = curcpu;
2945 	cache = &zone->uz_cpu[cpu];
2946 
2947 	/*
2948 	 * Since we have locked the zone we may as well send back our stats.
2949 	 */
2950 	atomic_add_long(&zone->uz_allocs, cache->uc_allocs);
2951 	atomic_add_long(&zone->uz_frees, cache->uc_frees);
2952 	cache->uc_allocs = 0;
2953 	cache->uc_frees = 0;
2954 
2955 	bucket = cache->uc_freebucket;
2956 	if (bucket != NULL && bucket->ub_cnt < bucket->ub_entries) {
2957 		ZONE_UNLOCK(zone);
2958 		goto zfree_start;
2959 	}
2960 	cache->uc_freebucket = NULL;
2961 	/* We are no longer associated with this CPU. */
2962 	critical_exit();
2963 
2964 	if ((zone->uz_flags & UMA_ZONE_NUMA) != 0)
2965 		domain = PCPU_GET(domain);
2966 	else
2967 		domain = 0;
2968 	zdom = &zone->uz_domain[0];
2969 
2970 	/* Can we throw this on the zone full list? */
2971 	if (bucket != NULL) {
2972 		CTR3(KTR_UMA,
2973 		    "uma_zfree: zone %s(%p) putting bucket %p on free list",
2974 		    zone->uz_name, zone, bucket);
2975 		/* ub_cnt is pointing to the last free item */
2976 		KASSERT(bucket->ub_cnt != 0,
2977 		    ("uma_zfree: Attempting to insert an empty bucket onto the full list.\n"));
2978 		if ((zone->uz_flags & UMA_ZONE_NOBUCKETCACHE) != 0) {
2979 			ZONE_UNLOCK(zone);
2980 			bucket_drain(zone, bucket);
2981 			bucket_free(zone, bucket, udata);
2982 			goto zfree_restart;
2983 		} else
2984 			LIST_INSERT_HEAD(&zdom->uzd_buckets, bucket, ub_link);
2985 	}
2986 
2987 	/*
2988 	 * We bump the uz count when the cache size is insufficient to
2989 	 * handle the working set.
2990 	 */
2991 	if (lockfail && zone->uz_count < BUCKET_MAX)
2992 		zone->uz_count++;
2993 	ZONE_UNLOCK(zone);
2994 
2995 	bucket = bucket_alloc(zone, udata, M_NOWAIT);
2996 	CTR3(KTR_UMA, "uma_zfree: zone %s(%p) allocated bucket %p",
2997 	    zone->uz_name, zone, bucket);
2998 	if (bucket) {
2999 		critical_enter();
3000 		cpu = curcpu;
3001 		cache = &zone->uz_cpu[cpu];
3002 		if (cache->uc_freebucket == NULL &&
3003 		    ((zone->uz_flags & UMA_ZONE_NUMA) == 0 ||
3004 		    domain == PCPU_GET(domain))) {
3005 			cache->uc_freebucket = bucket;
3006 			goto zfree_start;
3007 		}
3008 		/*
3009 		 * We lost the race, start over.  We have to drop our
3010 		 * critical section to free the bucket.
3011 		 */
3012 		critical_exit();
3013 		bucket_free(zone, bucket, udata);
3014 		goto zfree_restart;
3015 	}
3016 
3017 	/*
3018 	 * If nothing else caught this, we'll just do an internal free.
3019 	 */
3020 zfree_item:
3021 	zone_free_item(zone, item, udata, SKIP_DTOR);
3022 
3023 	return;
3024 }
3025 
3026 void
3027 uma_zfree_domain(uma_zone_t zone, void *item, void *udata)
3028 {
3029 
3030 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
3031 	random_harvest_fast_uma(&zone, sizeof(zone), 1, RANDOM_UMA);
3032 
3033 	CTR2(KTR_UMA, "uma_zfree_domain thread %x zone %s", curthread,
3034 	    zone->uz_name);
3035 
3036 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
3037 	    ("uma_zfree_domain: called with spinlock or critical section held"));
3038 
3039         /* uma_zfree(..., NULL) does nothing, to match free(9). */
3040         if (item == NULL)
3041                 return;
3042 	zone_free_item(zone, item, udata, SKIP_NONE);
3043 }
3044 
3045 static void
3046 slab_free_item(uma_keg_t keg, uma_slab_t slab, void *item)
3047 {
3048 	uma_domain_t dom;
3049 	uint8_t freei;
3050 
3051 	mtx_assert(&keg->uk_lock, MA_OWNED);
3052 	MPASS(keg == slab->us_keg);
3053 
3054 	dom = &keg->uk_domain[slab->us_domain];
3055 
3056 	/* Do we need to remove from any lists? */
3057 	if (slab->us_freecount+1 == keg->uk_ipers) {
3058 		LIST_REMOVE(slab, us_link);
3059 		LIST_INSERT_HEAD(&dom->ud_free_slab, slab, us_link);
3060 	} else if (slab->us_freecount == 0) {
3061 		LIST_REMOVE(slab, us_link);
3062 		LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
3063 	}
3064 
3065 	/* Slab management. */
3066 	freei = ((uintptr_t)item - (uintptr_t)slab->us_data) / keg->uk_rsize;
3067 	BIT_SET(SLAB_SETSIZE, freei, &slab->us_free);
3068 	slab->us_freecount++;
3069 
3070 	/* Keg statistics. */
3071 	keg->uk_free++;
3072 }
3073 
3074 static void
3075 zone_release(uma_zone_t zone, void **bucket, int cnt)
3076 {
3077 	void *item;
3078 	uma_slab_t slab;
3079 	uma_keg_t keg;
3080 	uint8_t *mem;
3081 	int clearfull;
3082 	int i;
3083 
3084 	clearfull = 0;
3085 	keg = zone_first_keg(zone);
3086 	KEG_LOCK(keg);
3087 	for (i = 0; i < cnt; i++) {
3088 		item = bucket[i];
3089 		if (!(zone->uz_flags & UMA_ZONE_VTOSLAB)) {
3090 			mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
3091 			if (zone->uz_flags & UMA_ZONE_HASH) {
3092 				slab = hash_sfind(&keg->uk_hash, mem);
3093 			} else {
3094 				mem += keg->uk_pgoff;
3095 				slab = (uma_slab_t)mem;
3096 			}
3097 		} else {
3098 			slab = vtoslab((vm_offset_t)item);
3099 			if (slab->us_keg != keg) {
3100 				KEG_UNLOCK(keg);
3101 				keg = slab->us_keg;
3102 				KEG_LOCK(keg);
3103 			}
3104 		}
3105 		slab_free_item(keg, slab, item);
3106 		if (keg->uk_flags & UMA_ZFLAG_FULL) {
3107 			if (keg->uk_pages < keg->uk_maxpages) {
3108 				keg->uk_flags &= ~UMA_ZFLAG_FULL;
3109 				clearfull = 1;
3110 			}
3111 
3112 			/*
3113 			 * We can handle one more allocation. Since we're
3114 			 * clearing ZFLAG_FULL, wake up all procs blocked
3115 			 * on pages. This should be uncommon, so keeping this
3116 			 * simple for now (rather than adding count of blocked
3117 			 * threads etc).
3118 			 */
3119 			wakeup(keg);
3120 		}
3121 	}
3122 	KEG_UNLOCK(keg);
3123 	if (clearfull) {
3124 		ZONE_LOCK(zone);
3125 		zone->uz_flags &= ~UMA_ZFLAG_FULL;
3126 		wakeup(zone);
3127 		ZONE_UNLOCK(zone);
3128 	}
3129 
3130 }
3131 
3132 /*
3133  * Frees a single item to any zone.
3134  *
3135  * Arguments:
3136  *	zone   The zone to free to
3137  *	item   The item we're freeing
3138  *	udata  User supplied data for the dtor
3139  *	skip   Skip dtors and finis
3140  */
3141 static void
3142 zone_free_item(uma_zone_t zone, void *item, void *udata, enum zfreeskip skip)
3143 {
3144 
3145 #ifdef INVARIANTS
3146 	if (skip == SKIP_NONE) {
3147 		if (zone->uz_flags & UMA_ZONE_MALLOC)
3148 			uma_dbg_free(zone, udata, item);
3149 		else
3150 			uma_dbg_free(zone, NULL, item);
3151 	}
3152 #endif
3153 	if (skip < SKIP_DTOR && zone->uz_dtor)
3154 		zone->uz_dtor(item, zone->uz_size, udata);
3155 
3156 	if (skip < SKIP_FINI && zone->uz_fini)
3157 		zone->uz_fini(item, zone->uz_size);
3158 
3159 	atomic_add_long(&zone->uz_frees, 1);
3160 	zone->uz_release(zone->uz_arg, &item, 1);
3161 }
3162 
3163 /* See uma.h */
3164 int
3165 uma_zone_set_max(uma_zone_t zone, int nitems)
3166 {
3167 	uma_keg_t keg;
3168 
3169 	keg = zone_first_keg(zone);
3170 	if (keg == NULL)
3171 		return (0);
3172 	KEG_LOCK(keg);
3173 	keg->uk_maxpages = (nitems / keg->uk_ipers) * keg->uk_ppera;
3174 	if (keg->uk_maxpages * keg->uk_ipers < nitems)
3175 		keg->uk_maxpages += keg->uk_ppera;
3176 	nitems = (keg->uk_maxpages / keg->uk_ppera) * keg->uk_ipers;
3177 	KEG_UNLOCK(keg);
3178 
3179 	return (nitems);
3180 }
3181 
3182 /* See uma.h */
3183 int
3184 uma_zone_get_max(uma_zone_t zone)
3185 {
3186 	int nitems;
3187 	uma_keg_t keg;
3188 
3189 	keg = zone_first_keg(zone);
3190 	if (keg == NULL)
3191 		return (0);
3192 	KEG_LOCK(keg);
3193 	nitems = (keg->uk_maxpages / keg->uk_ppera) * keg->uk_ipers;
3194 	KEG_UNLOCK(keg);
3195 
3196 	return (nitems);
3197 }
3198 
3199 /* See uma.h */
3200 void
3201 uma_zone_set_warning(uma_zone_t zone, const char *warning)
3202 {
3203 
3204 	ZONE_LOCK(zone);
3205 	zone->uz_warning = warning;
3206 	ZONE_UNLOCK(zone);
3207 }
3208 
3209 /* See uma.h */
3210 void
3211 uma_zone_set_maxaction(uma_zone_t zone, uma_maxaction_t maxaction)
3212 {
3213 
3214 	ZONE_LOCK(zone);
3215 	TASK_INIT(&zone->uz_maxaction, 0, (task_fn_t *)maxaction, zone);
3216 	ZONE_UNLOCK(zone);
3217 }
3218 
3219 /* See uma.h */
3220 int
3221 uma_zone_get_cur(uma_zone_t zone)
3222 {
3223 	int64_t nitems;
3224 	u_int i;
3225 
3226 	ZONE_LOCK(zone);
3227 	nitems = zone->uz_allocs - zone->uz_frees;
3228 	CPU_FOREACH(i) {
3229 		/*
3230 		 * See the comment in sysctl_vm_zone_stats() regarding the
3231 		 * safety of accessing the per-cpu caches. With the zone lock
3232 		 * held, it is safe, but can potentially result in stale data.
3233 		 */
3234 		nitems += zone->uz_cpu[i].uc_allocs -
3235 		    zone->uz_cpu[i].uc_frees;
3236 	}
3237 	ZONE_UNLOCK(zone);
3238 
3239 	return (nitems < 0 ? 0 : nitems);
3240 }
3241 
3242 /* See uma.h */
3243 void
3244 uma_zone_set_init(uma_zone_t zone, uma_init uminit)
3245 {
3246 	uma_keg_t keg;
3247 
3248 	keg = zone_first_keg(zone);
3249 	KASSERT(keg != NULL, ("uma_zone_set_init: Invalid zone type"));
3250 	KEG_LOCK(keg);
3251 	KASSERT(keg->uk_pages == 0,
3252 	    ("uma_zone_set_init on non-empty keg"));
3253 	keg->uk_init = uminit;
3254 	KEG_UNLOCK(keg);
3255 }
3256 
3257 /* See uma.h */
3258 void
3259 uma_zone_set_fini(uma_zone_t zone, uma_fini fini)
3260 {
3261 	uma_keg_t keg;
3262 
3263 	keg = zone_first_keg(zone);
3264 	KASSERT(keg != NULL, ("uma_zone_set_fini: Invalid zone type"));
3265 	KEG_LOCK(keg);
3266 	KASSERT(keg->uk_pages == 0,
3267 	    ("uma_zone_set_fini on non-empty keg"));
3268 	keg->uk_fini = fini;
3269 	KEG_UNLOCK(keg);
3270 }
3271 
3272 /* See uma.h */
3273 void
3274 uma_zone_set_zinit(uma_zone_t zone, uma_init zinit)
3275 {
3276 
3277 	ZONE_LOCK(zone);
3278 	KASSERT(zone_first_keg(zone)->uk_pages == 0,
3279 	    ("uma_zone_set_zinit on non-empty keg"));
3280 	zone->uz_init = zinit;
3281 	ZONE_UNLOCK(zone);
3282 }
3283 
3284 /* See uma.h */
3285 void
3286 uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini)
3287 {
3288 
3289 	ZONE_LOCK(zone);
3290 	KASSERT(zone_first_keg(zone)->uk_pages == 0,
3291 	    ("uma_zone_set_zfini on non-empty keg"));
3292 	zone->uz_fini = zfini;
3293 	ZONE_UNLOCK(zone);
3294 }
3295 
3296 /* See uma.h */
3297 /* XXX uk_freef is not actually used with the zone locked */
3298 void
3299 uma_zone_set_freef(uma_zone_t zone, uma_free freef)
3300 {
3301 	uma_keg_t keg;
3302 
3303 	keg = zone_first_keg(zone);
3304 	KASSERT(keg != NULL, ("uma_zone_set_freef: Invalid zone type"));
3305 	KEG_LOCK(keg);
3306 	keg->uk_freef = freef;
3307 	KEG_UNLOCK(keg);
3308 }
3309 
3310 /* See uma.h */
3311 /* XXX uk_allocf is not actually used with the zone locked */
3312 void
3313 uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf)
3314 {
3315 	uma_keg_t keg;
3316 
3317 	keg = zone_first_keg(zone);
3318 	KEG_LOCK(keg);
3319 	keg->uk_allocf = allocf;
3320 	KEG_UNLOCK(keg);
3321 }
3322 
3323 /* See uma.h */
3324 void
3325 uma_zone_reserve(uma_zone_t zone, int items)
3326 {
3327 	uma_keg_t keg;
3328 
3329 	keg = zone_first_keg(zone);
3330 	if (keg == NULL)
3331 		return;
3332 	KEG_LOCK(keg);
3333 	keg->uk_reserve = items;
3334 	KEG_UNLOCK(keg);
3335 
3336 	return;
3337 }
3338 
3339 /* See uma.h */
3340 int
3341 uma_zone_reserve_kva(uma_zone_t zone, int count)
3342 {
3343 	uma_keg_t keg;
3344 	vm_offset_t kva;
3345 	u_int pages;
3346 
3347 	keg = zone_first_keg(zone);
3348 	if (keg == NULL)
3349 		return (0);
3350 	pages = count / keg->uk_ipers;
3351 
3352 	if (pages * keg->uk_ipers < count)
3353 		pages++;
3354 	pages *= keg->uk_ppera;
3355 
3356 #ifdef UMA_MD_SMALL_ALLOC
3357 	if (keg->uk_ppera > 1) {
3358 #else
3359 	if (1) {
3360 #endif
3361 		kva = kva_alloc((vm_size_t)pages * PAGE_SIZE);
3362 		if (kva == 0)
3363 			return (0);
3364 	} else
3365 		kva = 0;
3366 	KEG_LOCK(keg);
3367 	keg->uk_kva = kva;
3368 	keg->uk_offset = 0;
3369 	keg->uk_maxpages = pages;
3370 #ifdef UMA_MD_SMALL_ALLOC
3371 	keg->uk_allocf = (keg->uk_ppera > 1) ? noobj_alloc : uma_small_alloc;
3372 #else
3373 	keg->uk_allocf = noobj_alloc;
3374 #endif
3375 	keg->uk_flags |= UMA_ZONE_NOFREE;
3376 	KEG_UNLOCK(keg);
3377 
3378 	return (1);
3379 }
3380 
3381 /* See uma.h */
3382 void
3383 uma_prealloc(uma_zone_t zone, int items)
3384 {
3385 	uma_domain_t dom;
3386 	uma_slab_t slab;
3387 	uma_keg_t keg;
3388 	int domain, slabs;
3389 
3390 	keg = zone_first_keg(zone);
3391 	if (keg == NULL)
3392 		return;
3393 	KEG_LOCK(keg);
3394 	slabs = items / keg->uk_ipers;
3395 	domain = 0;
3396 	if (slabs * keg->uk_ipers < items)
3397 		slabs++;
3398 	while (slabs > 0) {
3399 		slab = keg_alloc_slab(keg, zone, domain, M_WAITOK);
3400 		if (slab == NULL)
3401 			break;
3402 		MPASS(slab->us_keg == keg);
3403 		dom = &keg->uk_domain[slab->us_domain];
3404 		LIST_INSERT_HEAD(&dom->ud_free_slab, slab, us_link);
3405 		slabs--;
3406 		domain = (domain + 1) % vm_ndomains;
3407 	}
3408 	KEG_UNLOCK(keg);
3409 }
3410 
3411 /* See uma.h */
3412 static void
3413 uma_reclaim_locked(bool kmem_danger)
3414 {
3415 
3416 	CTR0(KTR_UMA, "UMA: vm asked us to release pages!");
3417 	sx_assert(&uma_drain_lock, SA_XLOCKED);
3418 	bucket_enable();
3419 	zone_foreach(zone_drain);
3420 	if (vm_page_count_min() || kmem_danger) {
3421 		cache_drain_safe(NULL);
3422 		zone_foreach(zone_drain);
3423 	}
3424 	/*
3425 	 * Some slabs may have been freed but this zone will be visited early
3426 	 * we visit again so that we can free pages that are empty once other
3427 	 * zones are drained.  We have to do the same for buckets.
3428 	 */
3429 	zone_drain(slabzone);
3430 	bucket_zone_drain();
3431 }
3432 
3433 void
3434 uma_reclaim(void)
3435 {
3436 
3437 	sx_xlock(&uma_drain_lock);
3438 	uma_reclaim_locked(false);
3439 	sx_xunlock(&uma_drain_lock);
3440 }
3441 
3442 static volatile int uma_reclaim_needed;
3443 
3444 void
3445 uma_reclaim_wakeup(void)
3446 {
3447 
3448 	if (atomic_fetchadd_int(&uma_reclaim_needed, 1) == 0)
3449 		wakeup(uma_reclaim);
3450 }
3451 
3452 void
3453 uma_reclaim_worker(void *arg __unused)
3454 {
3455 
3456 	for (;;) {
3457 		sx_xlock(&uma_drain_lock);
3458 		while (atomic_load_int(&uma_reclaim_needed) == 0)
3459 			sx_sleep(uma_reclaim, &uma_drain_lock, PVM, "umarcl",
3460 			    hz);
3461 		sx_xunlock(&uma_drain_lock);
3462 		EVENTHANDLER_INVOKE(vm_lowmem, VM_LOW_KMEM);
3463 		sx_xlock(&uma_drain_lock);
3464 		uma_reclaim_locked(true);
3465 		atomic_store_int(&uma_reclaim_needed, 0);
3466 		sx_xunlock(&uma_drain_lock);
3467 		/* Don't fire more than once per-second. */
3468 		pause("umarclslp", hz);
3469 	}
3470 }
3471 
3472 /* See uma.h */
3473 int
3474 uma_zone_exhausted(uma_zone_t zone)
3475 {
3476 	int full;
3477 
3478 	ZONE_LOCK(zone);
3479 	full = (zone->uz_flags & UMA_ZFLAG_FULL);
3480 	ZONE_UNLOCK(zone);
3481 	return (full);
3482 }
3483 
3484 int
3485 uma_zone_exhausted_nolock(uma_zone_t zone)
3486 {
3487 	return (zone->uz_flags & UMA_ZFLAG_FULL);
3488 }
3489 
3490 void *
3491 uma_large_malloc_domain(vm_size_t size, int domain, int wait)
3492 {
3493 	vm_offset_t addr;
3494 	uma_slab_t slab;
3495 
3496 	slab = zone_alloc_item(slabzone, NULL, domain, wait);
3497 	if (slab == NULL)
3498 		return (NULL);
3499 	if (domain == UMA_ANYDOMAIN)
3500 		addr = kmem_malloc(kernel_arena, size, wait);
3501 	else
3502 		addr = kmem_malloc_domain(domain, size, wait);
3503 	if (addr != 0) {
3504 		vsetslab(addr, slab);
3505 		slab->us_data = (void *)addr;
3506 		slab->us_flags = UMA_SLAB_KERNEL | UMA_SLAB_MALLOC;
3507 		slab->us_size = size;
3508 		slab->us_domain = vm_phys_domain(PHYS_TO_VM_PAGE(
3509 		    pmap_kextract(addr)));
3510 		uma_total_inc(size);
3511 	} else {
3512 		zone_free_item(slabzone, slab, NULL, SKIP_NONE);
3513 	}
3514 
3515 	return ((void *)addr);
3516 }
3517 
3518 void *
3519 uma_large_malloc(vm_size_t size, int wait)
3520 {
3521 
3522 	return uma_large_malloc_domain(size, UMA_ANYDOMAIN, wait);
3523 }
3524 
3525 void
3526 uma_large_free(uma_slab_t slab)
3527 {
3528 
3529 	KASSERT((slab->us_flags & UMA_SLAB_KERNEL) != 0,
3530 	    ("uma_large_free:  Memory not allocated with uma_large_malloc."));
3531 	kmem_free(kernel_arena, (vm_offset_t)slab->us_data, slab->us_size);
3532 	uma_total_dec(slab->us_size);
3533 	zone_free_item(slabzone, slab, NULL, SKIP_NONE);
3534 }
3535 
3536 static void
3537 uma_zero_item(void *item, uma_zone_t zone)
3538 {
3539 	int i;
3540 
3541 	if (zone->uz_flags & UMA_ZONE_PCPU) {
3542 		CPU_FOREACH(i)
3543 			bzero(zpcpu_get_cpu(item, i), zone->uz_size);
3544 	} else
3545 		bzero(item, zone->uz_size);
3546 }
3547 
3548 unsigned long
3549 uma_limit(void)
3550 {
3551 
3552 	return (uma_kmem_limit);
3553 }
3554 
3555 void
3556 uma_set_limit(unsigned long limit)
3557 {
3558 
3559 	uma_kmem_limit = limit;
3560 }
3561 
3562 unsigned long
3563 uma_size(void)
3564 {
3565 
3566 	return (uma_kmem_total);
3567 }
3568 
3569 long
3570 uma_avail(void)
3571 {
3572 
3573 	return (uma_kmem_limit - uma_kmem_total);
3574 }
3575 
3576 void
3577 uma_print_stats(void)
3578 {
3579 	zone_foreach(uma_print_zone);
3580 }
3581 
3582 static void
3583 slab_print(uma_slab_t slab)
3584 {
3585 	printf("slab: keg %p, data %p, freecount %d\n",
3586 		slab->us_keg, slab->us_data, slab->us_freecount);
3587 }
3588 
3589 static void
3590 cache_print(uma_cache_t cache)
3591 {
3592 	printf("alloc: %p(%d), free: %p(%d)\n",
3593 		cache->uc_allocbucket,
3594 		cache->uc_allocbucket?cache->uc_allocbucket->ub_cnt:0,
3595 		cache->uc_freebucket,
3596 		cache->uc_freebucket?cache->uc_freebucket->ub_cnt:0);
3597 }
3598 
3599 static void
3600 uma_print_keg(uma_keg_t keg)
3601 {
3602 	uma_domain_t dom;
3603 	uma_slab_t slab;
3604 	int i;
3605 
3606 	printf("keg: %s(%p) size %d(%d) flags %#x ipers %d ppera %d "
3607 	    "out %d free %d limit %d\n",
3608 	    keg->uk_name, keg, keg->uk_size, keg->uk_rsize, keg->uk_flags,
3609 	    keg->uk_ipers, keg->uk_ppera,
3610 	    (keg->uk_pages / keg->uk_ppera) * keg->uk_ipers - keg->uk_free,
3611 	    keg->uk_free, (keg->uk_maxpages / keg->uk_ppera) * keg->uk_ipers);
3612 	for (i = 0; i < vm_ndomains; i++) {
3613 		dom = &keg->uk_domain[i];
3614 		printf("Part slabs:\n");
3615 		LIST_FOREACH(slab, &dom->ud_part_slab, us_link)
3616 			slab_print(slab);
3617 		printf("Free slabs:\n");
3618 		LIST_FOREACH(slab, &dom->ud_free_slab, us_link)
3619 			slab_print(slab);
3620 		printf("Full slabs:\n");
3621 		LIST_FOREACH(slab, &dom->ud_full_slab, us_link)
3622 			slab_print(slab);
3623 	}
3624 }
3625 
3626 void
3627 uma_print_zone(uma_zone_t zone)
3628 {
3629 	uma_cache_t cache;
3630 	uma_klink_t kl;
3631 	int i;
3632 
3633 	printf("zone: %s(%p) size %d flags %#x\n",
3634 	    zone->uz_name, zone, zone->uz_size, zone->uz_flags);
3635 	LIST_FOREACH(kl, &zone->uz_kegs, kl_link)
3636 		uma_print_keg(kl->kl_keg);
3637 	CPU_FOREACH(i) {
3638 		cache = &zone->uz_cpu[i];
3639 		printf("CPU %d Cache:\n", i);
3640 		cache_print(cache);
3641 	}
3642 }
3643 
3644 #ifdef DDB
3645 /*
3646  * Generate statistics across both the zone and its per-cpu cache's.  Return
3647  * desired statistics if the pointer is non-NULL for that statistic.
3648  *
3649  * Note: does not update the zone statistics, as it can't safely clear the
3650  * per-CPU cache statistic.
3651  *
3652  * XXXRW: Following the uc_allocbucket and uc_freebucket pointers here isn't
3653  * safe from off-CPU; we should modify the caches to track this information
3654  * directly so that we don't have to.
3655  */
3656 static void
3657 uma_zone_sumstat(uma_zone_t z, int *cachefreep, uint64_t *allocsp,
3658     uint64_t *freesp, uint64_t *sleepsp)
3659 {
3660 	uma_cache_t cache;
3661 	uint64_t allocs, frees, sleeps;
3662 	int cachefree, cpu;
3663 
3664 	allocs = frees = sleeps = 0;
3665 	cachefree = 0;
3666 	CPU_FOREACH(cpu) {
3667 		cache = &z->uz_cpu[cpu];
3668 		if (cache->uc_allocbucket != NULL)
3669 			cachefree += cache->uc_allocbucket->ub_cnt;
3670 		if (cache->uc_freebucket != NULL)
3671 			cachefree += cache->uc_freebucket->ub_cnt;
3672 		allocs += cache->uc_allocs;
3673 		frees += cache->uc_frees;
3674 	}
3675 	allocs += z->uz_allocs;
3676 	frees += z->uz_frees;
3677 	sleeps += z->uz_sleeps;
3678 	if (cachefreep != NULL)
3679 		*cachefreep = cachefree;
3680 	if (allocsp != NULL)
3681 		*allocsp = allocs;
3682 	if (freesp != NULL)
3683 		*freesp = frees;
3684 	if (sleepsp != NULL)
3685 		*sleepsp = sleeps;
3686 }
3687 #endif /* DDB */
3688 
3689 static int
3690 sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS)
3691 {
3692 	uma_keg_t kz;
3693 	uma_zone_t z;
3694 	int count;
3695 
3696 	count = 0;
3697 	rw_rlock(&uma_rwlock);
3698 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3699 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
3700 			count++;
3701 	}
3702 	rw_runlock(&uma_rwlock);
3703 	return (sysctl_handle_int(oidp, &count, 0, req));
3704 }
3705 
3706 static int
3707 sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS)
3708 {
3709 	struct uma_stream_header ush;
3710 	struct uma_type_header uth;
3711 	struct uma_percpu_stat *ups;
3712 	uma_bucket_t bucket;
3713 	uma_zone_domain_t zdom;
3714 	struct sbuf sbuf;
3715 	uma_cache_t cache;
3716 	uma_klink_t kl;
3717 	uma_keg_t kz;
3718 	uma_zone_t z;
3719 	uma_keg_t k;
3720 	int count, error, i;
3721 
3722 	error = sysctl_wire_old_buffer(req, 0);
3723 	if (error != 0)
3724 		return (error);
3725 	sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
3726 	sbuf_clear_flags(&sbuf, SBUF_INCLUDENUL);
3727 	ups = malloc((mp_maxid + 1) * sizeof(*ups), M_TEMP, M_WAITOK);
3728 
3729 	count = 0;
3730 	rw_rlock(&uma_rwlock);
3731 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3732 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
3733 			count++;
3734 	}
3735 
3736 	/*
3737 	 * Insert stream header.
3738 	 */
3739 	bzero(&ush, sizeof(ush));
3740 	ush.ush_version = UMA_STREAM_VERSION;
3741 	ush.ush_maxcpus = (mp_maxid + 1);
3742 	ush.ush_count = count;
3743 	(void)sbuf_bcat(&sbuf, &ush, sizeof(ush));
3744 
3745 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3746 		LIST_FOREACH(z, &kz->uk_zones, uz_link) {
3747 			bzero(&uth, sizeof(uth));
3748 			ZONE_LOCK(z);
3749 			strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
3750 			uth.uth_align = kz->uk_align;
3751 			uth.uth_size = kz->uk_size;
3752 			uth.uth_rsize = kz->uk_rsize;
3753 			LIST_FOREACH(kl, &z->uz_kegs, kl_link) {
3754 				k = kl->kl_keg;
3755 				uth.uth_maxpages += k->uk_maxpages;
3756 				uth.uth_pages += k->uk_pages;
3757 				uth.uth_keg_free += k->uk_free;
3758 				uth.uth_limit = (k->uk_maxpages / k->uk_ppera)
3759 				    * k->uk_ipers;
3760 			}
3761 
3762 			/*
3763 			 * A zone is secondary is it is not the first entry
3764 			 * on the keg's zone list.
3765 			 */
3766 			if ((z->uz_flags & UMA_ZONE_SECONDARY) &&
3767 			    (LIST_FIRST(&kz->uk_zones) != z))
3768 				uth.uth_zone_flags = UTH_ZONE_SECONDARY;
3769 
3770 			for (i = 0; i < vm_ndomains; i++) {
3771 				zdom = &z->uz_domain[i];
3772 				LIST_FOREACH(bucket, &zdom->uzd_buckets,
3773 				    ub_link)
3774 					uth.uth_zone_free += bucket->ub_cnt;
3775 			}
3776 			uth.uth_allocs = z->uz_allocs;
3777 			uth.uth_frees = z->uz_frees;
3778 			uth.uth_fails = z->uz_fails;
3779 			uth.uth_sleeps = z->uz_sleeps;
3780 			/*
3781 			 * While it is not normally safe to access the cache
3782 			 * bucket pointers while not on the CPU that owns the
3783 			 * cache, we only allow the pointers to be exchanged
3784 			 * without the zone lock held, not invalidated, so
3785 			 * accept the possible race associated with bucket
3786 			 * exchange during monitoring.
3787 			 */
3788 			for (i = 0; i < mp_maxid + 1; i++) {
3789 				bzero(&ups[i], sizeof(*ups));
3790 				if (kz->uk_flags & UMA_ZFLAG_INTERNAL ||
3791 				    CPU_ABSENT(i))
3792 					continue;
3793 				cache = &z->uz_cpu[i];
3794 				if (cache->uc_allocbucket != NULL)
3795 					ups[i].ups_cache_free +=
3796 					    cache->uc_allocbucket->ub_cnt;
3797 				if (cache->uc_freebucket != NULL)
3798 					ups[i].ups_cache_free +=
3799 					    cache->uc_freebucket->ub_cnt;
3800 				ups[i].ups_allocs = cache->uc_allocs;
3801 				ups[i].ups_frees = cache->uc_frees;
3802 			}
3803 			ZONE_UNLOCK(z);
3804 			(void)sbuf_bcat(&sbuf, &uth, sizeof(uth));
3805 			for (i = 0; i < mp_maxid + 1; i++)
3806 				(void)sbuf_bcat(&sbuf, &ups[i], sizeof(ups[i]));
3807 		}
3808 	}
3809 	rw_runlock(&uma_rwlock);
3810 	error = sbuf_finish(&sbuf);
3811 	sbuf_delete(&sbuf);
3812 	free(ups, M_TEMP);
3813 	return (error);
3814 }
3815 
3816 int
3817 sysctl_handle_uma_zone_max(SYSCTL_HANDLER_ARGS)
3818 {
3819 	uma_zone_t zone = *(uma_zone_t *)arg1;
3820 	int error, max;
3821 
3822 	max = uma_zone_get_max(zone);
3823 	error = sysctl_handle_int(oidp, &max, 0, req);
3824 	if (error || !req->newptr)
3825 		return (error);
3826 
3827 	uma_zone_set_max(zone, max);
3828 
3829 	return (0);
3830 }
3831 
3832 int
3833 sysctl_handle_uma_zone_cur(SYSCTL_HANDLER_ARGS)
3834 {
3835 	uma_zone_t zone = *(uma_zone_t *)arg1;
3836 	int cur;
3837 
3838 	cur = uma_zone_get_cur(zone);
3839 	return (sysctl_handle_int(oidp, &cur, 0, req));
3840 }
3841 
3842 #ifdef INVARIANTS
3843 static uma_slab_t
3844 uma_dbg_getslab(uma_zone_t zone, void *item)
3845 {
3846 	uma_slab_t slab;
3847 	uma_keg_t keg;
3848 	uint8_t *mem;
3849 
3850 	mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
3851 	if (zone->uz_flags & UMA_ZONE_VTOSLAB) {
3852 		slab = vtoslab((vm_offset_t)mem);
3853 	} else {
3854 		/*
3855 		 * It is safe to return the slab here even though the
3856 		 * zone is unlocked because the item's allocation state
3857 		 * essentially holds a reference.
3858 		 */
3859 		ZONE_LOCK(zone);
3860 		keg = LIST_FIRST(&zone->uz_kegs)->kl_keg;
3861 		if (keg->uk_flags & UMA_ZONE_HASH)
3862 			slab = hash_sfind(&keg->uk_hash, mem);
3863 		else
3864 			slab = (uma_slab_t)(mem + keg->uk_pgoff);
3865 		ZONE_UNLOCK(zone);
3866 	}
3867 
3868 	return (slab);
3869 }
3870 
3871 /*
3872  * Set up the slab's freei data such that uma_dbg_free can function.
3873  *
3874  */
3875 static void
3876 uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item)
3877 {
3878 	uma_keg_t keg;
3879 	int freei;
3880 
3881 	if (zone_first_keg(zone) == NULL)
3882 		return;
3883 	if (slab == NULL) {
3884 		slab = uma_dbg_getslab(zone, item);
3885 		if (slab == NULL)
3886 			panic("uma: item %p did not belong to zone %s\n",
3887 			    item, zone->uz_name);
3888 	}
3889 	keg = slab->us_keg;
3890 	freei = ((uintptr_t)item - (uintptr_t)slab->us_data) / keg->uk_rsize;
3891 
3892 	if (BIT_ISSET(SLAB_SETSIZE, freei, &slab->us_debugfree))
3893 		panic("Duplicate alloc of %p from zone %p(%s) slab %p(%d)\n",
3894 		    item, zone, zone->uz_name, slab, freei);
3895 	BIT_SET_ATOMIC(SLAB_SETSIZE, freei, &slab->us_debugfree);
3896 
3897 	return;
3898 }
3899 
3900 /*
3901  * Verifies freed addresses.  Checks for alignment, valid slab membership
3902  * and duplicate frees.
3903  *
3904  */
3905 static void
3906 uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item)
3907 {
3908 	uma_keg_t keg;
3909 	int freei;
3910 
3911 	if (zone_first_keg(zone) == NULL)
3912 		return;
3913 	if (slab == NULL) {
3914 		slab = uma_dbg_getslab(zone, item);
3915 		if (slab == NULL)
3916 			panic("uma: Freed item %p did not belong to zone %s\n",
3917 			    item, zone->uz_name);
3918 	}
3919 	keg = slab->us_keg;
3920 	freei = ((uintptr_t)item - (uintptr_t)slab->us_data) / keg->uk_rsize;
3921 
3922 	if (freei >= keg->uk_ipers)
3923 		panic("Invalid free of %p from zone %p(%s) slab %p(%d)\n",
3924 		    item, zone, zone->uz_name, slab, freei);
3925 
3926 	if (((freei * keg->uk_rsize) + slab->us_data) != item)
3927 		panic("Unaligned free of %p from zone %p(%s) slab %p(%d)\n",
3928 		    item, zone, zone->uz_name, slab, freei);
3929 
3930 	if (!BIT_ISSET(SLAB_SETSIZE, freei, &slab->us_debugfree))
3931 		panic("Duplicate free of %p from zone %p(%s) slab %p(%d)\n",
3932 		    item, zone, zone->uz_name, slab, freei);
3933 
3934 	BIT_CLR_ATOMIC(SLAB_SETSIZE, freei, &slab->us_debugfree);
3935 }
3936 #endif /* INVARIANTS */
3937 
3938 #ifdef DDB
3939 DB_SHOW_COMMAND(uma, db_show_uma)
3940 {
3941 	uma_bucket_t bucket;
3942 	uma_keg_t kz;
3943 	uma_zone_t z;
3944 	uma_zone_domain_t zdom;
3945 	uint64_t allocs, frees, sleeps;
3946 	int cachefree, i;
3947 
3948 	db_printf("%18s %8s %8s %8s %12s %8s %8s\n", "Zone", "Size", "Used",
3949 	    "Free", "Requests", "Sleeps", "Bucket");
3950 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3951 		LIST_FOREACH(z, &kz->uk_zones, uz_link) {
3952 			if (kz->uk_flags & UMA_ZFLAG_INTERNAL) {
3953 				allocs = z->uz_allocs;
3954 				frees = z->uz_frees;
3955 				sleeps = z->uz_sleeps;
3956 				cachefree = 0;
3957 			} else
3958 				uma_zone_sumstat(z, &cachefree, &allocs,
3959 				    &frees, &sleeps);
3960 			if (!((z->uz_flags & UMA_ZONE_SECONDARY) &&
3961 			    (LIST_FIRST(&kz->uk_zones) != z)))
3962 				cachefree += kz->uk_free;
3963 			for (i = 0; i < vm_ndomains; i++) {
3964 				zdom = &z->uz_domain[i];
3965 				LIST_FOREACH(bucket, &zdom->uzd_buckets,
3966 				    ub_link)
3967 					cachefree += bucket->ub_cnt;
3968 			}
3969 			db_printf("%18s %8ju %8jd %8d %12ju %8ju %8u\n",
3970 			    z->uz_name, (uintmax_t)kz->uk_size,
3971 			    (intmax_t)(allocs - frees), cachefree,
3972 			    (uintmax_t)allocs, sleeps, z->uz_count);
3973 			if (db_pager_quit)
3974 				return;
3975 		}
3976 	}
3977 }
3978 
3979 DB_SHOW_COMMAND(umacache, db_show_umacache)
3980 {
3981 	uma_bucket_t bucket;
3982 	uma_zone_t z;
3983 	uma_zone_domain_t zdom;
3984 	uint64_t allocs, frees;
3985 	int cachefree, i;
3986 
3987 	db_printf("%18s %8s %8s %8s %12s %8s\n", "Zone", "Size", "Used", "Free",
3988 	    "Requests", "Bucket");
3989 	LIST_FOREACH(z, &uma_cachezones, uz_link) {
3990 		uma_zone_sumstat(z, &cachefree, &allocs, &frees, NULL);
3991 		for (i = 0; i < vm_ndomains; i++) {
3992 			zdom = &z->uz_domain[i];
3993 			LIST_FOREACH(bucket, &zdom->uzd_buckets, ub_link)
3994 				cachefree += bucket->ub_cnt;
3995 		}
3996 		db_printf("%18s %8ju %8jd %8d %12ju %8u\n",
3997 		    z->uz_name, (uintmax_t)z->uz_size,
3998 		    (intmax_t)(allocs - frees), cachefree,
3999 		    (uintmax_t)allocs, z->uz_count);
4000 		if (db_pager_quit)
4001 			return;
4002 	}
4003 }
4004 #endif	/* DDB */
4005