xref: /freebsd/sys/vm/uma_core.c (revision 1e66f787c838b5af7de716e266caf4e5d190d54b)
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 	KASSERT((arg->flags & (UMA_ZONE_MAXBUCKET | UMA_ZONE_NOBUCKET)) !=
1685 	    (UMA_ZONE_MAXBUCKET | UMA_ZONE_NOBUCKET),
1686 	    ("Invalid zone flag combination"));
1687 	if ((arg->flags & UMA_ZONE_MAXBUCKET) != 0)
1688 		zone->uz_count = BUCKET_MAX;
1689 	else if ((arg->flags & UMA_ZONE_NOBUCKET) != 0)
1690 		zone->uz_count = 0;
1691 	else
1692 		zone->uz_count = bucket_select(zone->uz_size);
1693 	zone->uz_count_min = zone->uz_count;
1694 
1695 	return (0);
1696 }
1697 
1698 /*
1699  * Keg header dtor.  This frees all data, destroys locks, frees the hash
1700  * table and removes the keg from the global list.
1701  *
1702  * Arguments/Returns follow uma_dtor specifications
1703  *	udata  unused
1704  */
1705 static void
1706 keg_dtor(void *arg, int size, void *udata)
1707 {
1708 	uma_keg_t keg;
1709 
1710 	keg = (uma_keg_t)arg;
1711 	KEG_LOCK(keg);
1712 	if (keg->uk_free != 0) {
1713 		printf("Freed UMA keg (%s) was not empty (%d items). "
1714 		    " Lost %d pages of memory.\n",
1715 		    keg->uk_name ? keg->uk_name : "",
1716 		    keg->uk_free, keg->uk_pages);
1717 	}
1718 	KEG_UNLOCK(keg);
1719 
1720 	hash_free(&keg->uk_hash);
1721 
1722 	KEG_LOCK_FINI(keg);
1723 }
1724 
1725 /*
1726  * Zone header dtor.
1727  *
1728  * Arguments/Returns follow uma_dtor specifications
1729  *	udata  unused
1730  */
1731 static void
1732 zone_dtor(void *arg, int size, void *udata)
1733 {
1734 	uma_klink_t klink;
1735 	uma_zone_t zone;
1736 	uma_keg_t keg;
1737 
1738 	zone = (uma_zone_t)arg;
1739 	keg = zone_first_keg(zone);
1740 
1741 	if (!(zone->uz_flags & UMA_ZFLAG_INTERNAL))
1742 		cache_drain(zone);
1743 
1744 	rw_wlock(&uma_rwlock);
1745 	LIST_REMOVE(zone, uz_link);
1746 	rw_wunlock(&uma_rwlock);
1747 	/*
1748 	 * XXX there are some races here where
1749 	 * the zone can be drained but zone lock
1750 	 * released and then refilled before we
1751 	 * remove it... we dont care for now
1752 	 */
1753 	zone_drain_wait(zone, M_WAITOK);
1754 	/*
1755 	 * Unlink all of our kegs.
1756 	 */
1757 	while ((klink = LIST_FIRST(&zone->uz_kegs)) != NULL) {
1758 		klink->kl_keg = NULL;
1759 		LIST_REMOVE(klink, kl_link);
1760 		if (klink == &zone->uz_klink)
1761 			continue;
1762 		free(klink, M_TEMP);
1763 	}
1764 	/*
1765 	 * We only destroy kegs from non secondary zones.
1766 	 */
1767 	if (keg != NULL && (zone->uz_flags & UMA_ZONE_SECONDARY) == 0)  {
1768 		rw_wlock(&uma_rwlock);
1769 		LIST_REMOVE(keg, uk_link);
1770 		rw_wunlock(&uma_rwlock);
1771 		zone_free_item(kegs, keg, NULL, SKIP_NONE);
1772 	}
1773 	ZONE_LOCK_FINI(zone);
1774 }
1775 
1776 /*
1777  * Traverses every zone in the system and calls a callback
1778  *
1779  * Arguments:
1780  *	zfunc  A pointer to a function which accepts a zone
1781  *		as an argument.
1782  *
1783  * Returns:
1784  *	Nothing
1785  */
1786 static void
1787 zone_foreach(void (*zfunc)(uma_zone_t))
1788 {
1789 	uma_keg_t keg;
1790 	uma_zone_t zone;
1791 
1792 	rw_rlock(&uma_rwlock);
1793 	LIST_FOREACH(keg, &uma_kegs, uk_link) {
1794 		LIST_FOREACH(zone, &keg->uk_zones, uz_link)
1795 			zfunc(zone);
1796 	}
1797 	rw_runlock(&uma_rwlock);
1798 }
1799 
1800 /*
1801  * Count how many pages do we need to bootstrap.  VM supplies
1802  * its need in early zones in the argument, we add up our zones,
1803  * which consist of: UMA Slabs, UMA Hash and 9 Bucket zones. The
1804  * zone of zones and zone of kegs are accounted separately.
1805  */
1806 #define	UMA_BOOT_ZONES	11
1807 /* Zone of zones and zone of kegs have arbitrary alignment. */
1808 #define	UMA_BOOT_ALIGN	32
1809 static int zsize, ksize;
1810 int
1811 uma_startup_count(int vm_zones)
1812 {
1813 	int zones, pages;
1814 
1815 	ksize = sizeof(struct uma_keg) +
1816 	    (sizeof(struct uma_domain) * vm_ndomains);
1817 	zsize = sizeof(struct uma_zone) +
1818 	    (sizeof(struct uma_cache) * (mp_maxid + 1)) +
1819 	    (sizeof(struct uma_zone_domain) * vm_ndomains);
1820 
1821 	/*
1822 	 * Memory for the zone of kegs and its keg,
1823 	 * and for zone of zones.
1824 	 */
1825 	pages = howmany(roundup(zsize, CACHE_LINE_SIZE) * 2 +
1826 	    roundup(ksize, CACHE_LINE_SIZE), PAGE_SIZE);
1827 
1828 #ifdef	UMA_MD_SMALL_ALLOC
1829 	zones = UMA_BOOT_ZONES;
1830 #else
1831 	zones = UMA_BOOT_ZONES + vm_zones;
1832 	vm_zones = 0;
1833 #endif
1834 
1835 	/* Memory for the rest of startup zones, UMA and VM, ... */
1836 	if (zsize > UMA_SLAB_SPACE)
1837 		pages += (zones + vm_zones) *
1838 		    howmany(roundup2(zsize, UMA_BOOT_ALIGN), UMA_SLAB_SIZE);
1839 	else if (roundup2(zsize, UMA_BOOT_ALIGN) > UMA_SLAB_SPACE)
1840 		pages += zones;
1841 	else
1842 		pages += howmany(zones,
1843 		    UMA_SLAB_SPACE / roundup2(zsize, UMA_BOOT_ALIGN));
1844 
1845 	/* ... and their kegs. Note that zone of zones allocates a keg! */
1846 	pages += howmany(zones + 1,
1847 	    UMA_SLAB_SPACE / roundup2(ksize, UMA_BOOT_ALIGN));
1848 
1849 	/*
1850 	 * Most of startup zones are not going to be offpages, that's
1851 	 * why we use UMA_SLAB_SPACE instead of UMA_SLAB_SIZE in all
1852 	 * calculations.  Some large bucket zones will be offpage, and
1853 	 * thus will allocate hashes.  We take conservative approach
1854 	 * and assume that all zones may allocate hash.  This may give
1855 	 * us some positive inaccuracy, usually an extra single page.
1856 	 */
1857 	pages += howmany(zones, UMA_SLAB_SPACE /
1858 	    (sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT));
1859 
1860 	return (pages);
1861 }
1862 
1863 void
1864 uma_startup(void *mem, int npages)
1865 {
1866 	struct uma_zctor_args args;
1867 	uma_keg_t masterkeg;
1868 	uintptr_t m;
1869 
1870 #ifdef DIAGNOSTIC
1871 	printf("Entering %s with %d boot pages configured\n", __func__, npages);
1872 #endif
1873 
1874 	rw_init(&uma_rwlock, "UMA lock");
1875 
1876 	/* Use bootpages memory for the zone of zones and zone of kegs. */
1877 	m = (uintptr_t)mem;
1878 	zones = (uma_zone_t)m;
1879 	m += roundup(zsize, CACHE_LINE_SIZE);
1880 	kegs = (uma_zone_t)m;
1881 	m += roundup(zsize, CACHE_LINE_SIZE);
1882 	masterkeg = (uma_keg_t)m;
1883 	m += roundup(ksize, CACHE_LINE_SIZE);
1884 	m = roundup(m, PAGE_SIZE);
1885 	npages -= (m - (uintptr_t)mem) / PAGE_SIZE;
1886 	mem = (void *)m;
1887 
1888 	/* "manually" create the initial zone */
1889 	memset(&args, 0, sizeof(args));
1890 	args.name = "UMA Kegs";
1891 	args.size = ksize;
1892 	args.ctor = keg_ctor;
1893 	args.dtor = keg_dtor;
1894 	args.uminit = zero_init;
1895 	args.fini = NULL;
1896 	args.keg = masterkeg;
1897 	args.align = UMA_BOOT_ALIGN - 1;
1898 	args.flags = UMA_ZFLAG_INTERNAL;
1899 	zone_ctor(kegs, zsize, &args, M_WAITOK);
1900 
1901 	bootmem = mem;
1902 	boot_pages = npages;
1903 
1904 	args.name = "UMA Zones";
1905 	args.size = zsize;
1906 	args.ctor = zone_ctor;
1907 	args.dtor = zone_dtor;
1908 	args.uminit = zero_init;
1909 	args.fini = NULL;
1910 	args.keg = NULL;
1911 	args.align = UMA_BOOT_ALIGN - 1;
1912 	args.flags = UMA_ZFLAG_INTERNAL;
1913 	zone_ctor(zones, zsize, &args, M_WAITOK);
1914 
1915 	/* Now make a zone for slab headers */
1916 	slabzone = uma_zcreate("UMA Slabs",
1917 				sizeof(struct uma_slab),
1918 				NULL, NULL, NULL, NULL,
1919 				UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
1920 
1921 	hashzone = uma_zcreate("UMA Hash",
1922 	    sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT,
1923 	    NULL, NULL, NULL, NULL,
1924 	    UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
1925 
1926 	bucket_init();
1927 
1928 	booted = BOOT_STRAPPED;
1929 }
1930 
1931 void
1932 uma_startup1(void)
1933 {
1934 
1935 #ifdef DIAGNOSTIC
1936 	printf("Entering %s with %d boot pages left\n", __func__, boot_pages);
1937 #endif
1938 	booted = BOOT_PAGEALLOC;
1939 }
1940 
1941 void
1942 uma_startup2(void)
1943 {
1944 
1945 #ifdef DIAGNOSTIC
1946 	printf("Entering %s with %d boot pages left\n", __func__, boot_pages);
1947 #endif
1948 	booted = BOOT_BUCKETS;
1949 	sx_init(&uma_drain_lock, "umadrain");
1950 	bucket_enable();
1951 }
1952 
1953 /*
1954  * Initialize our callout handle
1955  *
1956  */
1957 static void
1958 uma_startup3(void)
1959 {
1960 
1961 	booted = BOOT_RUNNING;
1962 	callout_init(&uma_callout, 1);
1963 	callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
1964 }
1965 
1966 static uma_keg_t
1967 uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini,
1968 		int align, uint32_t flags)
1969 {
1970 	struct uma_kctor_args args;
1971 
1972 	args.size = size;
1973 	args.uminit = uminit;
1974 	args.fini = fini;
1975 	args.align = (align == UMA_ALIGN_CACHE) ? uma_align_cache : align;
1976 	args.flags = flags;
1977 	args.zone = zone;
1978 	return (zone_alloc_item(kegs, &args, UMA_ANYDOMAIN, M_WAITOK));
1979 }
1980 
1981 /* Public functions */
1982 /* See uma.h */
1983 void
1984 uma_set_align(int align)
1985 {
1986 
1987 	if (align != UMA_ALIGN_CACHE)
1988 		uma_align_cache = align;
1989 }
1990 
1991 /* See uma.h */
1992 uma_zone_t
1993 uma_zcreate(const char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
1994 		uma_init uminit, uma_fini fini, int align, uint32_t flags)
1995 
1996 {
1997 	struct uma_zctor_args args;
1998 	uma_zone_t res;
1999 	bool locked;
2000 
2001 	KASSERT(powerof2(align + 1), ("invalid zone alignment %d for \"%s\"",
2002 	    align, name));
2003 
2004 	/* This stuff is essential for the zone ctor */
2005 	memset(&args, 0, sizeof(args));
2006 	args.name = name;
2007 	args.size = size;
2008 	args.ctor = ctor;
2009 	args.dtor = dtor;
2010 	args.uminit = uminit;
2011 	args.fini = fini;
2012 #ifdef  INVARIANTS
2013 	/*
2014 	 * If a zone is being created with an empty constructor and
2015 	 * destructor, pass UMA constructor/destructor which checks for
2016 	 * memory use after free.
2017 	 */
2018 	if ((!(flags & (UMA_ZONE_ZINIT | UMA_ZONE_NOFREE))) &&
2019 	    ctor == NULL && dtor == NULL && uminit == NULL && fini == NULL) {
2020 		args.ctor = trash_ctor;
2021 		args.dtor = trash_dtor;
2022 		args.uminit = trash_init;
2023 		args.fini = trash_fini;
2024 	}
2025 #endif
2026 	args.align = align;
2027 	args.flags = flags;
2028 	args.keg = NULL;
2029 
2030 	if (booted < BOOT_BUCKETS) {
2031 		locked = false;
2032 	} else {
2033 		sx_slock(&uma_drain_lock);
2034 		locked = true;
2035 	}
2036 	res = zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK);
2037 	if (locked)
2038 		sx_sunlock(&uma_drain_lock);
2039 	return (res);
2040 }
2041 
2042 /* See uma.h */
2043 uma_zone_t
2044 uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
2045 		    uma_init zinit, uma_fini zfini, uma_zone_t master)
2046 {
2047 	struct uma_zctor_args args;
2048 	uma_keg_t keg;
2049 	uma_zone_t res;
2050 	bool locked;
2051 
2052 	keg = zone_first_keg(master);
2053 	memset(&args, 0, sizeof(args));
2054 	args.name = name;
2055 	args.size = keg->uk_size;
2056 	args.ctor = ctor;
2057 	args.dtor = dtor;
2058 	args.uminit = zinit;
2059 	args.fini = zfini;
2060 	args.align = keg->uk_align;
2061 	args.flags = keg->uk_flags | UMA_ZONE_SECONDARY;
2062 	args.keg = keg;
2063 
2064 	if (booted < BOOT_BUCKETS) {
2065 		locked = false;
2066 	} else {
2067 		sx_slock(&uma_drain_lock);
2068 		locked = true;
2069 	}
2070 	/* XXX Attaches only one keg of potentially many. */
2071 	res = zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK);
2072 	if (locked)
2073 		sx_sunlock(&uma_drain_lock);
2074 	return (res);
2075 }
2076 
2077 /* See uma.h */
2078 uma_zone_t
2079 uma_zcache_create(char *name, int size, uma_ctor ctor, uma_dtor dtor,
2080 		    uma_init zinit, uma_fini zfini, uma_import zimport,
2081 		    uma_release zrelease, void *arg, int flags)
2082 {
2083 	struct uma_zctor_args args;
2084 
2085 	memset(&args, 0, sizeof(args));
2086 	args.name = name;
2087 	args.size = size;
2088 	args.ctor = ctor;
2089 	args.dtor = dtor;
2090 	args.uminit = zinit;
2091 	args.fini = zfini;
2092 	args.import = zimport;
2093 	args.release = zrelease;
2094 	args.arg = arg;
2095 	args.align = 0;
2096 	args.flags = flags;
2097 
2098 	return (zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK));
2099 }
2100 
2101 static void
2102 zone_lock_pair(uma_zone_t a, uma_zone_t b)
2103 {
2104 	if (a < b) {
2105 		ZONE_LOCK(a);
2106 		mtx_lock_flags(b->uz_lockptr, MTX_DUPOK);
2107 	} else {
2108 		ZONE_LOCK(b);
2109 		mtx_lock_flags(a->uz_lockptr, MTX_DUPOK);
2110 	}
2111 }
2112 
2113 static void
2114 zone_unlock_pair(uma_zone_t a, uma_zone_t b)
2115 {
2116 
2117 	ZONE_UNLOCK(a);
2118 	ZONE_UNLOCK(b);
2119 }
2120 
2121 int
2122 uma_zsecond_add(uma_zone_t zone, uma_zone_t master)
2123 {
2124 	uma_klink_t klink;
2125 	uma_klink_t kl;
2126 	int error;
2127 
2128 	error = 0;
2129 	klink = malloc(sizeof(*klink), M_TEMP, M_WAITOK | M_ZERO);
2130 
2131 	zone_lock_pair(zone, master);
2132 	/*
2133 	 * zone must use vtoslab() to resolve objects and must already be
2134 	 * a secondary.
2135 	 */
2136 	if ((zone->uz_flags & (UMA_ZONE_VTOSLAB | UMA_ZONE_SECONDARY))
2137 	    != (UMA_ZONE_VTOSLAB | UMA_ZONE_SECONDARY)) {
2138 		error = EINVAL;
2139 		goto out;
2140 	}
2141 	/*
2142 	 * The new master must also use vtoslab().
2143 	 */
2144 	if ((zone->uz_flags & UMA_ZONE_VTOSLAB) != UMA_ZONE_VTOSLAB) {
2145 		error = EINVAL;
2146 		goto out;
2147 	}
2148 
2149 	/*
2150 	 * The underlying object must be the same size.  rsize
2151 	 * may be different.
2152 	 */
2153 	if (master->uz_size != zone->uz_size) {
2154 		error = E2BIG;
2155 		goto out;
2156 	}
2157 	/*
2158 	 * Put it at the end of the list.
2159 	 */
2160 	klink->kl_keg = zone_first_keg(master);
2161 	LIST_FOREACH(kl, &zone->uz_kegs, kl_link) {
2162 		if (LIST_NEXT(kl, kl_link) == NULL) {
2163 			LIST_INSERT_AFTER(kl, klink, kl_link);
2164 			break;
2165 		}
2166 	}
2167 	klink = NULL;
2168 	zone->uz_flags |= UMA_ZFLAG_MULTI;
2169 	zone->uz_slab = zone_fetch_slab_multi;
2170 
2171 out:
2172 	zone_unlock_pair(zone, master);
2173 	if (klink != NULL)
2174 		free(klink, M_TEMP);
2175 
2176 	return (error);
2177 }
2178 
2179 
2180 /* See uma.h */
2181 void
2182 uma_zdestroy(uma_zone_t zone)
2183 {
2184 
2185 	sx_slock(&uma_drain_lock);
2186 	zone_free_item(zones, zone, NULL, SKIP_NONE);
2187 	sx_sunlock(&uma_drain_lock);
2188 }
2189 
2190 void
2191 uma_zwait(uma_zone_t zone)
2192 {
2193 	void *item;
2194 
2195 	item = uma_zalloc_arg(zone, NULL, M_WAITOK);
2196 	uma_zfree(zone, item);
2197 }
2198 
2199 /* See uma.h */
2200 void *
2201 uma_zalloc_arg(uma_zone_t zone, void *udata, int flags)
2202 {
2203 	uma_zone_domain_t zdom;
2204 	uma_bucket_t bucket;
2205 	uma_cache_t cache;
2206 	void *item;
2207 	int cpu, domain, lockfail;
2208 
2209 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
2210 	random_harvest_fast_uma(&zone, sizeof(zone), 1, RANDOM_UMA);
2211 
2212 	/* This is the fast path allocation */
2213 	CTR4(KTR_UMA, "uma_zalloc_arg thread %x zone %s(%p) flags %d",
2214 	    curthread, zone->uz_name, zone, flags);
2215 
2216 	if (flags & M_WAITOK) {
2217 		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
2218 		    "uma_zalloc_arg: zone \"%s\"", zone->uz_name);
2219 	}
2220 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
2221 	    ("uma_zalloc_arg: called with spinlock or critical section held"));
2222 
2223 #ifdef DEBUG_MEMGUARD
2224 	if (memguard_cmp_zone(zone)) {
2225 		item = memguard_alloc(zone->uz_size, flags);
2226 		if (item != NULL) {
2227 			if (zone->uz_init != NULL &&
2228 			    zone->uz_init(item, zone->uz_size, flags) != 0)
2229 				return (NULL);
2230 			if (zone->uz_ctor != NULL &&
2231 			    zone->uz_ctor(item, zone->uz_size, udata,
2232 			    flags) != 0) {
2233 			    	zone->uz_fini(item, zone->uz_size);
2234 				return (NULL);
2235 			}
2236 			return (item);
2237 		}
2238 		/* This is unfortunate but should not be fatal. */
2239 	}
2240 #endif
2241 	/*
2242 	 * If possible, allocate from the per-CPU cache.  There are two
2243 	 * requirements for safe access to the per-CPU cache: (1) the thread
2244 	 * accessing the cache must not be preempted or yield during access,
2245 	 * and (2) the thread must not migrate CPUs without switching which
2246 	 * cache it accesses.  We rely on a critical section to prevent
2247 	 * preemption and migration.  We release the critical section in
2248 	 * order to acquire the zone mutex if we are unable to allocate from
2249 	 * the current cache; when we re-acquire the critical section, we
2250 	 * must detect and handle migration if it has occurred.
2251 	 */
2252 	critical_enter();
2253 	cpu = curcpu;
2254 	cache = &zone->uz_cpu[cpu];
2255 
2256 zalloc_start:
2257 	bucket = cache->uc_allocbucket;
2258 	if (bucket != NULL && bucket->ub_cnt > 0) {
2259 		bucket->ub_cnt--;
2260 		item = bucket->ub_bucket[bucket->ub_cnt];
2261 #ifdef INVARIANTS
2262 		bucket->ub_bucket[bucket->ub_cnt] = NULL;
2263 #endif
2264 		KASSERT(item != NULL, ("uma_zalloc: Bucket pointer mangled."));
2265 		cache->uc_allocs++;
2266 		critical_exit();
2267 		if (zone->uz_ctor != NULL &&
2268 		    zone->uz_ctor(item, zone->uz_size, udata, flags) != 0) {
2269 			atomic_add_long(&zone->uz_fails, 1);
2270 			zone_free_item(zone, item, udata, SKIP_DTOR);
2271 			return (NULL);
2272 		}
2273 #ifdef INVARIANTS
2274 		uma_dbg_alloc(zone, NULL, item);
2275 #endif
2276 		if (flags & M_ZERO)
2277 			uma_zero_item(item, zone);
2278 		return (item);
2279 	}
2280 
2281 	/*
2282 	 * We have run out of items in our alloc bucket.
2283 	 * See if we can switch with our free bucket.
2284 	 */
2285 	bucket = cache->uc_freebucket;
2286 	if (bucket != NULL && bucket->ub_cnt > 0) {
2287 		CTR2(KTR_UMA,
2288 		    "uma_zalloc: zone %s(%p) swapping empty with alloc",
2289 		    zone->uz_name, zone);
2290 		cache->uc_freebucket = cache->uc_allocbucket;
2291 		cache->uc_allocbucket = bucket;
2292 		goto zalloc_start;
2293 	}
2294 
2295 	/*
2296 	 * Discard any empty allocation bucket while we hold no locks.
2297 	 */
2298 	bucket = cache->uc_allocbucket;
2299 	cache->uc_allocbucket = NULL;
2300 	critical_exit();
2301 	if (bucket != NULL)
2302 		bucket_free(zone, bucket, udata);
2303 
2304 	if (zone->uz_flags & UMA_ZONE_NUMA)
2305 		domain = PCPU_GET(domain);
2306 	else
2307 		domain = UMA_ANYDOMAIN;
2308 
2309 	/* Short-circuit for zones without buckets and low memory. */
2310 	if (zone->uz_count == 0 || bucketdisable)
2311 		goto zalloc_item;
2312 
2313 	/*
2314 	 * Attempt to retrieve the item from the per-CPU cache has failed, so
2315 	 * we must go back to the zone.  This requires the zone lock, so we
2316 	 * must drop the critical section, then re-acquire it when we go back
2317 	 * to the cache.  Since the critical section is released, we may be
2318 	 * preempted or migrate.  As such, make sure not to maintain any
2319 	 * thread-local state specific to the cache from prior to releasing
2320 	 * the critical section.
2321 	 */
2322 	lockfail = 0;
2323 	if (ZONE_TRYLOCK(zone) == 0) {
2324 		/* Record contention to size the buckets. */
2325 		ZONE_LOCK(zone);
2326 		lockfail = 1;
2327 	}
2328 	critical_enter();
2329 	cpu = curcpu;
2330 	cache = &zone->uz_cpu[cpu];
2331 
2332 	/*
2333 	 * Since we have locked the zone we may as well send back our stats.
2334 	 */
2335 	atomic_add_long(&zone->uz_allocs, cache->uc_allocs);
2336 	atomic_add_long(&zone->uz_frees, cache->uc_frees);
2337 	cache->uc_allocs = 0;
2338 	cache->uc_frees = 0;
2339 
2340 	/* See if we lost the race to fill the cache. */
2341 	if (cache->uc_allocbucket != NULL) {
2342 		ZONE_UNLOCK(zone);
2343 		goto zalloc_start;
2344 	}
2345 
2346 	/*
2347 	 * Check the zone's cache of buckets.
2348 	 */
2349 	if (domain == UMA_ANYDOMAIN)
2350 		zdom = &zone->uz_domain[0];
2351 	else
2352 		zdom = &zone->uz_domain[domain];
2353 	if ((bucket = LIST_FIRST(&zdom->uzd_buckets)) != NULL) {
2354 		KASSERT(bucket->ub_cnt != 0,
2355 		    ("uma_zalloc_arg: Returning an empty bucket."));
2356 
2357 		LIST_REMOVE(bucket, ub_link);
2358 		cache->uc_allocbucket = bucket;
2359 		ZONE_UNLOCK(zone);
2360 		goto zalloc_start;
2361 	}
2362 	/* We are no longer associated with this CPU. */
2363 	critical_exit();
2364 
2365 	/*
2366 	 * We bump the uz count when the cache size is insufficient to
2367 	 * handle the working set.
2368 	 */
2369 	if (lockfail && zone->uz_count < BUCKET_MAX)
2370 		zone->uz_count++;
2371 	ZONE_UNLOCK(zone);
2372 
2373 	/*
2374 	 * Now lets just fill a bucket and put it on the free list.  If that
2375 	 * works we'll restart the allocation from the beginning and it
2376 	 * will use the just filled bucket.
2377 	 */
2378 	bucket = zone_alloc_bucket(zone, udata, domain, flags);
2379 	CTR3(KTR_UMA, "uma_zalloc: zone %s(%p) bucket zone returned %p",
2380 	    zone->uz_name, zone, bucket);
2381 	if (bucket != NULL) {
2382 		ZONE_LOCK(zone);
2383 		critical_enter();
2384 		cpu = curcpu;
2385 		cache = &zone->uz_cpu[cpu];
2386 		/*
2387 		 * See if we lost the race or were migrated.  Cache the
2388 		 * initialized bucket to make this less likely or claim
2389 		 * the memory directly.
2390 		 */
2391 		if (cache->uc_allocbucket != NULL ||
2392 		    (zone->uz_flags & UMA_ZONE_NUMA &&
2393 		    domain != PCPU_GET(domain)))
2394 			LIST_INSERT_HEAD(&zdom->uzd_buckets, bucket, ub_link);
2395 		else
2396 			cache->uc_allocbucket = bucket;
2397 		ZONE_UNLOCK(zone);
2398 		goto zalloc_start;
2399 	}
2400 
2401 	/*
2402 	 * We may not be able to get a bucket so return an actual item.
2403 	 */
2404 zalloc_item:
2405 	item = zone_alloc_item(zone, udata, domain, flags);
2406 
2407 	return (item);
2408 }
2409 
2410 void *
2411 uma_zalloc_domain(uma_zone_t zone, void *udata, int domain, int flags)
2412 {
2413 
2414 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
2415 	random_harvest_fast_uma(&zone, sizeof(zone), 1, RANDOM_UMA);
2416 
2417 	/* This is the fast path allocation */
2418 	CTR5(KTR_UMA,
2419 	    "uma_zalloc_domain thread %x zone %s(%p) domain %d flags %d",
2420 	    curthread, zone->uz_name, zone, domain, flags);
2421 
2422 	if (flags & M_WAITOK) {
2423 		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
2424 		    "uma_zalloc_domain: zone \"%s\"", zone->uz_name);
2425 	}
2426 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
2427 	    ("uma_zalloc_domain: called with spinlock or critical section held"));
2428 
2429 	return (zone_alloc_item(zone, udata, domain, flags));
2430 }
2431 
2432 /*
2433  * Find a slab with some space.  Prefer slabs that are partially used over those
2434  * that are totally full.  This helps to reduce fragmentation.
2435  *
2436  * If 'rr' is 1, search all domains starting from 'domain'.  Otherwise check
2437  * only 'domain'.
2438  */
2439 static uma_slab_t
2440 keg_first_slab(uma_keg_t keg, int domain, int rr)
2441 {
2442 	uma_domain_t dom;
2443 	uma_slab_t slab;
2444 	int start;
2445 
2446 	KASSERT(domain >= 0 && domain < vm_ndomains,
2447 	    ("keg_first_slab: domain %d out of range", domain));
2448 
2449 	slab = NULL;
2450 	start = domain;
2451 	do {
2452 		dom = &keg->uk_domain[domain];
2453 		if (!LIST_EMPTY(&dom->ud_part_slab))
2454 			return (LIST_FIRST(&dom->ud_part_slab));
2455 		if (!LIST_EMPTY(&dom->ud_free_slab)) {
2456 			slab = LIST_FIRST(&dom->ud_free_slab);
2457 			LIST_REMOVE(slab, us_link);
2458 			LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
2459 			return (slab);
2460 		}
2461 		if (rr)
2462 			domain = (domain + 1) % vm_ndomains;
2463 	} while (domain != start);
2464 
2465 	return (NULL);
2466 }
2467 
2468 static uma_slab_t
2469 keg_fetch_slab(uma_keg_t keg, uma_zone_t zone, int rdomain, int flags)
2470 {
2471 	uma_domain_t dom;
2472 	uma_slab_t slab;
2473 	int allocflags, domain, reserve, rr, start;
2474 
2475 	mtx_assert(&keg->uk_lock, MA_OWNED);
2476 	slab = NULL;
2477 	reserve = 0;
2478 	allocflags = flags;
2479 	if ((flags & M_USE_RESERVE) == 0)
2480 		reserve = keg->uk_reserve;
2481 
2482 	/*
2483 	 * Round-robin for non first-touch zones when there is more than one
2484 	 * domain.
2485 	 */
2486 	if (vm_ndomains == 1)
2487 		rdomain = 0;
2488 	rr = rdomain == UMA_ANYDOMAIN;
2489 	if (rr) {
2490 		keg->uk_cursor = (keg->uk_cursor + 1) % vm_ndomains;
2491 		domain = start = keg->uk_cursor;
2492 		/* Only block on the second pass. */
2493 		if ((flags & (M_WAITOK | M_NOVM)) == M_WAITOK)
2494 			allocflags = (allocflags & ~M_WAITOK) | M_NOWAIT;
2495 	} else
2496 		domain = start = rdomain;
2497 
2498 again:
2499 	do {
2500 		if (keg->uk_free > reserve &&
2501 		    (slab = keg_first_slab(keg, domain, rr)) != NULL) {
2502 			MPASS(slab->us_keg == keg);
2503 			return (slab);
2504 		}
2505 
2506 		/*
2507 		 * M_NOVM means don't ask at all!
2508 		 */
2509 		if (flags & M_NOVM)
2510 			break;
2511 
2512 		if (keg->uk_maxpages && keg->uk_pages >= keg->uk_maxpages) {
2513 			keg->uk_flags |= UMA_ZFLAG_FULL;
2514 			/*
2515 			 * If this is not a multi-zone, set the FULL bit.
2516 			 * Otherwise slab_multi() takes care of it.
2517 			 */
2518 			if ((zone->uz_flags & UMA_ZFLAG_MULTI) == 0) {
2519 				zone->uz_flags |= UMA_ZFLAG_FULL;
2520 				zone_log_warning(zone);
2521 				zone_maxaction(zone);
2522 			}
2523 			if (flags & M_NOWAIT)
2524 				return (NULL);
2525 			zone->uz_sleeps++;
2526 			msleep(keg, &keg->uk_lock, PVM, "keglimit", 0);
2527 			continue;
2528 		}
2529 		slab = keg_alloc_slab(keg, zone, domain, allocflags);
2530 		/*
2531 		 * If we got a slab here it's safe to mark it partially used
2532 		 * and return.  We assume that the caller is going to remove
2533 		 * at least one item.
2534 		 */
2535 		if (slab) {
2536 			MPASS(slab->us_keg == keg);
2537 			dom = &keg->uk_domain[slab->us_domain];
2538 			LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
2539 			return (slab);
2540 		}
2541 		if (rr) {
2542 			keg->uk_cursor = (keg->uk_cursor + 1) % vm_ndomains;
2543 			domain = keg->uk_cursor;
2544 		}
2545 	} while (domain != start);
2546 
2547 	/* Retry domain scan with blocking. */
2548 	if (allocflags != flags) {
2549 		allocflags = flags;
2550 		goto again;
2551 	}
2552 
2553 	/*
2554 	 * We might not have been able to get a slab but another cpu
2555 	 * could have while we were unlocked.  Check again before we
2556 	 * fail.
2557 	 */
2558 	if (keg->uk_free > reserve &&
2559 	    (slab = keg_first_slab(keg, domain, rr)) != NULL) {
2560 		MPASS(slab->us_keg == keg);
2561 		return (slab);
2562 	}
2563 	return (NULL);
2564 }
2565 
2566 static uma_slab_t
2567 zone_fetch_slab(uma_zone_t zone, uma_keg_t keg, int domain, int flags)
2568 {
2569 	uma_slab_t slab;
2570 
2571 	if (keg == NULL) {
2572 		keg = zone_first_keg(zone);
2573 		KEG_LOCK(keg);
2574 	}
2575 
2576 	for (;;) {
2577 		slab = keg_fetch_slab(keg, zone, domain, flags);
2578 		if (slab)
2579 			return (slab);
2580 		if (flags & (M_NOWAIT | M_NOVM))
2581 			break;
2582 	}
2583 	KEG_UNLOCK(keg);
2584 	return (NULL);
2585 }
2586 
2587 /*
2588  * uma_zone_fetch_slab_multi:  Fetches a slab from one available keg.  Returns
2589  * with the keg locked.  On NULL no lock is held.
2590  *
2591  * The last pointer is used to seed the search.  It is not required.
2592  */
2593 static uma_slab_t
2594 zone_fetch_slab_multi(uma_zone_t zone, uma_keg_t last, int domain, int rflags)
2595 {
2596 	uma_klink_t klink;
2597 	uma_slab_t slab;
2598 	uma_keg_t keg;
2599 	int flags;
2600 	int empty;
2601 	int full;
2602 
2603 	/*
2604 	 * Don't wait on the first pass.  This will skip limit tests
2605 	 * as well.  We don't want to block if we can find a provider
2606 	 * without blocking.
2607 	 */
2608 	flags = (rflags & ~M_WAITOK) | M_NOWAIT;
2609 	/*
2610 	 * Use the last slab allocated as a hint for where to start
2611 	 * the search.
2612 	 */
2613 	if (last != NULL) {
2614 		slab = keg_fetch_slab(last, zone, domain, flags);
2615 		if (slab)
2616 			return (slab);
2617 		KEG_UNLOCK(last);
2618 	}
2619 	/*
2620 	 * Loop until we have a slab incase of transient failures
2621 	 * while M_WAITOK is specified.  I'm not sure this is 100%
2622 	 * required but we've done it for so long now.
2623 	 */
2624 	for (;;) {
2625 		empty = 0;
2626 		full = 0;
2627 		/*
2628 		 * Search the available kegs for slabs.  Be careful to hold the
2629 		 * correct lock while calling into the keg layer.
2630 		 */
2631 		LIST_FOREACH(klink, &zone->uz_kegs, kl_link) {
2632 			keg = klink->kl_keg;
2633 			KEG_LOCK(keg);
2634 			if ((keg->uk_flags & UMA_ZFLAG_FULL) == 0) {
2635 				slab = keg_fetch_slab(keg, zone, domain, flags);
2636 				if (slab)
2637 					return (slab);
2638 			}
2639 			if (keg->uk_flags & UMA_ZFLAG_FULL)
2640 				full++;
2641 			else
2642 				empty++;
2643 			KEG_UNLOCK(keg);
2644 		}
2645 		if (rflags & (M_NOWAIT | M_NOVM))
2646 			break;
2647 		flags = rflags;
2648 		/*
2649 		 * All kegs are full.  XXX We can't atomically check all kegs
2650 		 * and sleep so just sleep for a short period and retry.
2651 		 */
2652 		if (full && !empty) {
2653 			ZONE_LOCK(zone);
2654 			zone->uz_flags |= UMA_ZFLAG_FULL;
2655 			zone->uz_sleeps++;
2656 			zone_log_warning(zone);
2657 			zone_maxaction(zone);
2658 			msleep(zone, zone->uz_lockptr, PVM,
2659 			    "zonelimit", hz/100);
2660 			zone->uz_flags &= ~UMA_ZFLAG_FULL;
2661 			ZONE_UNLOCK(zone);
2662 			continue;
2663 		}
2664 	}
2665 	return (NULL);
2666 }
2667 
2668 static void *
2669 slab_alloc_item(uma_keg_t keg, uma_slab_t slab)
2670 {
2671 	uma_domain_t dom;
2672 	void *item;
2673 	uint8_t freei;
2674 
2675 	MPASS(keg == slab->us_keg);
2676 	mtx_assert(&keg->uk_lock, MA_OWNED);
2677 
2678 	freei = BIT_FFS(SLAB_SETSIZE, &slab->us_free) - 1;
2679 	BIT_CLR(SLAB_SETSIZE, freei, &slab->us_free);
2680 	item = slab->us_data + (keg->uk_rsize * freei);
2681 	slab->us_freecount--;
2682 	keg->uk_free--;
2683 
2684 	/* Move this slab to the full list */
2685 	if (slab->us_freecount == 0) {
2686 		LIST_REMOVE(slab, us_link);
2687 		dom = &keg->uk_domain[slab->us_domain];
2688 		LIST_INSERT_HEAD(&dom->ud_full_slab, slab, us_link);
2689 	}
2690 
2691 	return (item);
2692 }
2693 
2694 static int
2695 zone_import(uma_zone_t zone, void **bucket, int max, int domain, int flags)
2696 {
2697 	uma_slab_t slab;
2698 	uma_keg_t keg;
2699 	int stripe;
2700 	int i;
2701 
2702 	slab = NULL;
2703 	keg = NULL;
2704 	/* Try to keep the buckets totally full */
2705 	for (i = 0; i < max; ) {
2706 		if ((slab = zone->uz_slab(zone, keg, domain, flags)) == NULL)
2707 			break;
2708 		keg = slab->us_keg;
2709 		stripe = howmany(max, vm_ndomains);
2710 		while (slab->us_freecount && i < max) {
2711 			bucket[i++] = slab_alloc_item(keg, slab);
2712 			if (keg->uk_free <= keg->uk_reserve)
2713 				break;
2714 #ifdef NUMA
2715 			/*
2716 			 * If the zone is striped we pick a new slab for every
2717 			 * N allocations.  Eliminating this conditional will
2718 			 * instead pick a new domain for each bucket rather
2719 			 * than stripe within each bucket.  The current option
2720 			 * produces more fragmentation and requires more cpu
2721 			 * time but yields better distribution.
2722 			 */
2723 			if ((zone->uz_flags & UMA_ZONE_NUMA) == 0 &&
2724 			    vm_ndomains > 1 && --stripe == 0)
2725 				break;
2726 #endif
2727 		}
2728 		/* Don't block if we allocated any successfully. */
2729 		flags &= ~M_WAITOK;
2730 		flags |= M_NOWAIT;
2731 	}
2732 	if (slab != NULL)
2733 		KEG_UNLOCK(keg);
2734 
2735 	return i;
2736 }
2737 
2738 static uma_bucket_t
2739 zone_alloc_bucket(uma_zone_t zone, void *udata, int domain, int flags)
2740 {
2741 	uma_bucket_t bucket;
2742 	int max;
2743 
2744 	/* Don't wait for buckets, preserve caller's NOVM setting. */
2745 	bucket = bucket_alloc(zone, udata, M_NOWAIT | (flags & M_NOVM));
2746 	if (bucket == NULL)
2747 		return (NULL);
2748 
2749 	max = MIN(bucket->ub_entries, zone->uz_count);
2750 	bucket->ub_cnt = zone->uz_import(zone->uz_arg, bucket->ub_bucket,
2751 	    max, domain, flags);
2752 
2753 	/*
2754 	 * Initialize the memory if necessary.
2755 	 */
2756 	if (bucket->ub_cnt != 0 && zone->uz_init != NULL) {
2757 		int i;
2758 
2759 		for (i = 0; i < bucket->ub_cnt; i++)
2760 			if (zone->uz_init(bucket->ub_bucket[i], zone->uz_size,
2761 			    flags) != 0)
2762 				break;
2763 		/*
2764 		 * If we couldn't initialize the whole bucket, put the
2765 		 * rest back onto the freelist.
2766 		 */
2767 		if (i != bucket->ub_cnt) {
2768 			zone->uz_release(zone->uz_arg, &bucket->ub_bucket[i],
2769 			    bucket->ub_cnt - i);
2770 #ifdef INVARIANTS
2771 			bzero(&bucket->ub_bucket[i],
2772 			    sizeof(void *) * (bucket->ub_cnt - i));
2773 #endif
2774 			bucket->ub_cnt = i;
2775 		}
2776 	}
2777 
2778 	if (bucket->ub_cnt == 0) {
2779 		bucket_free(zone, bucket, udata);
2780 		atomic_add_long(&zone->uz_fails, 1);
2781 		return (NULL);
2782 	}
2783 
2784 	return (bucket);
2785 }
2786 
2787 /*
2788  * Allocates a single item from a zone.
2789  *
2790  * Arguments
2791  *	zone   The zone to alloc for.
2792  *	udata  The data to be passed to the constructor.
2793  *	domain The domain to allocate from or UMA_ANYDOMAIN.
2794  *	flags  M_WAITOK, M_NOWAIT, M_ZERO.
2795  *
2796  * Returns
2797  *	NULL if there is no memory and M_NOWAIT is set
2798  *	An item if successful
2799  */
2800 
2801 static void *
2802 zone_alloc_item(uma_zone_t zone, void *udata, int domain, int flags)
2803 {
2804 	void *item;
2805 
2806 	item = NULL;
2807 
2808 	if (zone->uz_import(zone->uz_arg, &item, 1, domain, flags) != 1)
2809 		goto fail;
2810 	atomic_add_long(&zone->uz_allocs, 1);
2811 
2812 	/*
2813 	 * We have to call both the zone's init (not the keg's init)
2814 	 * and the zone's ctor.  This is because the item is going from
2815 	 * a keg slab directly to the user, and the user is expecting it
2816 	 * to be both zone-init'd as well as zone-ctor'd.
2817 	 */
2818 	if (zone->uz_init != NULL) {
2819 		if (zone->uz_init(item, zone->uz_size, flags) != 0) {
2820 			zone_free_item(zone, item, udata, SKIP_FINI);
2821 			goto fail;
2822 		}
2823 	}
2824 	if (zone->uz_ctor != NULL) {
2825 		if (zone->uz_ctor(item, zone->uz_size, udata, flags) != 0) {
2826 			zone_free_item(zone, item, udata, SKIP_DTOR);
2827 			goto fail;
2828 		}
2829 	}
2830 #ifdef INVARIANTS
2831 	uma_dbg_alloc(zone, NULL, item);
2832 #endif
2833 	if (flags & M_ZERO)
2834 		uma_zero_item(item, zone);
2835 
2836 	CTR3(KTR_UMA, "zone_alloc_item item %p from %s(%p)", item,
2837 	    zone->uz_name, zone);
2838 
2839 	return (item);
2840 
2841 fail:
2842 	CTR2(KTR_UMA, "zone_alloc_item failed from %s(%p)",
2843 	    zone->uz_name, zone);
2844 	atomic_add_long(&zone->uz_fails, 1);
2845 	return (NULL);
2846 }
2847 
2848 /* See uma.h */
2849 void
2850 uma_zfree_arg(uma_zone_t zone, void *item, void *udata)
2851 {
2852 	uma_cache_t cache;
2853 	uma_bucket_t bucket;
2854 	uma_zone_domain_t zdom;
2855 	int cpu, domain, lockfail;
2856 
2857 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
2858 	random_harvest_fast_uma(&zone, sizeof(zone), 1, RANDOM_UMA);
2859 
2860 	CTR2(KTR_UMA, "uma_zfree_arg thread %x zone %s", curthread,
2861 	    zone->uz_name);
2862 
2863 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
2864 	    ("uma_zfree_arg: called with spinlock or critical section held"));
2865 
2866         /* uma_zfree(..., NULL) does nothing, to match free(9). */
2867         if (item == NULL)
2868                 return;
2869 #ifdef DEBUG_MEMGUARD
2870 	if (is_memguard_addr(item)) {
2871 		if (zone->uz_dtor != NULL)
2872 			zone->uz_dtor(item, zone->uz_size, udata);
2873 		if (zone->uz_fini != NULL)
2874 			zone->uz_fini(item, zone->uz_size);
2875 		memguard_free(item);
2876 		return;
2877 	}
2878 #endif
2879 #ifdef INVARIANTS
2880 	if (zone->uz_flags & UMA_ZONE_MALLOC)
2881 		uma_dbg_free(zone, udata, item);
2882 	else
2883 		uma_dbg_free(zone, NULL, item);
2884 #endif
2885 	if (zone->uz_dtor != NULL)
2886 		zone->uz_dtor(item, zone->uz_size, udata);
2887 
2888 	/*
2889 	 * The race here is acceptable.  If we miss it we'll just have to wait
2890 	 * a little longer for the limits to be reset.
2891 	 */
2892 	if (zone->uz_flags & UMA_ZFLAG_FULL)
2893 		goto zfree_item;
2894 
2895 	/*
2896 	 * If possible, free to the per-CPU cache.  There are two
2897 	 * requirements for safe access to the per-CPU cache: (1) the thread
2898 	 * accessing the cache must not be preempted or yield during access,
2899 	 * and (2) the thread must not migrate CPUs without switching which
2900 	 * cache it accesses.  We rely on a critical section to prevent
2901 	 * preemption and migration.  We release the critical section in
2902 	 * order to acquire the zone mutex if we are unable to free to the
2903 	 * current cache; when we re-acquire the critical section, we must
2904 	 * detect and handle migration if it has occurred.
2905 	 */
2906 zfree_restart:
2907 	critical_enter();
2908 	cpu = curcpu;
2909 	cache = &zone->uz_cpu[cpu];
2910 
2911 zfree_start:
2912 	/*
2913 	 * Try to free into the allocbucket first to give LIFO ordering
2914 	 * for cache-hot datastructures.  Spill over into the freebucket
2915 	 * if necessary.  Alloc will swap them if one runs dry.
2916 	 */
2917 	bucket = cache->uc_allocbucket;
2918 	if (bucket == NULL || bucket->ub_cnt >= bucket->ub_entries)
2919 		bucket = cache->uc_freebucket;
2920 	if (bucket != NULL && bucket->ub_cnt < bucket->ub_entries) {
2921 		KASSERT(bucket->ub_bucket[bucket->ub_cnt] == NULL,
2922 		    ("uma_zfree: Freeing to non free bucket index."));
2923 		bucket->ub_bucket[bucket->ub_cnt] = item;
2924 		bucket->ub_cnt++;
2925 		cache->uc_frees++;
2926 		critical_exit();
2927 		return;
2928 	}
2929 
2930 	/*
2931 	 * We must go back the zone, which requires acquiring the zone lock,
2932 	 * which in turn means we must release and re-acquire the critical
2933 	 * section.  Since the critical section is released, we may be
2934 	 * preempted or migrate.  As such, make sure not to maintain any
2935 	 * thread-local state specific to the cache from prior to releasing
2936 	 * the critical section.
2937 	 */
2938 	critical_exit();
2939 	if (zone->uz_count == 0 || bucketdisable)
2940 		goto zfree_item;
2941 
2942 	lockfail = 0;
2943 	if (ZONE_TRYLOCK(zone) == 0) {
2944 		/* Record contention to size the buckets. */
2945 		ZONE_LOCK(zone);
2946 		lockfail = 1;
2947 	}
2948 	critical_enter();
2949 	cpu = curcpu;
2950 	cache = &zone->uz_cpu[cpu];
2951 
2952 	/*
2953 	 * Since we have locked the zone we may as well send back our stats.
2954 	 */
2955 	atomic_add_long(&zone->uz_allocs, cache->uc_allocs);
2956 	atomic_add_long(&zone->uz_frees, cache->uc_frees);
2957 	cache->uc_allocs = 0;
2958 	cache->uc_frees = 0;
2959 
2960 	bucket = cache->uc_freebucket;
2961 	if (bucket != NULL && bucket->ub_cnt < bucket->ub_entries) {
2962 		ZONE_UNLOCK(zone);
2963 		goto zfree_start;
2964 	}
2965 	cache->uc_freebucket = NULL;
2966 	/* We are no longer associated with this CPU. */
2967 	critical_exit();
2968 
2969 	if ((zone->uz_flags & UMA_ZONE_NUMA) != 0)
2970 		domain = PCPU_GET(domain);
2971 	else
2972 		domain = 0;
2973 	zdom = &zone->uz_domain[0];
2974 
2975 	/* Can we throw this on the zone full list? */
2976 	if (bucket != NULL) {
2977 		CTR3(KTR_UMA,
2978 		    "uma_zfree: zone %s(%p) putting bucket %p on free list",
2979 		    zone->uz_name, zone, bucket);
2980 		/* ub_cnt is pointing to the last free item */
2981 		KASSERT(bucket->ub_cnt != 0,
2982 		    ("uma_zfree: Attempting to insert an empty bucket onto the full list.\n"));
2983 		if ((zone->uz_flags & UMA_ZONE_NOBUCKETCACHE) != 0) {
2984 			ZONE_UNLOCK(zone);
2985 			bucket_drain(zone, bucket);
2986 			bucket_free(zone, bucket, udata);
2987 			goto zfree_restart;
2988 		} else
2989 			LIST_INSERT_HEAD(&zdom->uzd_buckets, bucket, ub_link);
2990 	}
2991 
2992 	/*
2993 	 * We bump the uz count when the cache size is insufficient to
2994 	 * handle the working set.
2995 	 */
2996 	if (lockfail && zone->uz_count < BUCKET_MAX)
2997 		zone->uz_count++;
2998 	ZONE_UNLOCK(zone);
2999 
3000 	bucket = bucket_alloc(zone, udata, M_NOWAIT);
3001 	CTR3(KTR_UMA, "uma_zfree: zone %s(%p) allocated bucket %p",
3002 	    zone->uz_name, zone, bucket);
3003 	if (bucket) {
3004 		critical_enter();
3005 		cpu = curcpu;
3006 		cache = &zone->uz_cpu[cpu];
3007 		if (cache->uc_freebucket == NULL &&
3008 		    ((zone->uz_flags & UMA_ZONE_NUMA) == 0 ||
3009 		    domain == PCPU_GET(domain))) {
3010 			cache->uc_freebucket = bucket;
3011 			goto zfree_start;
3012 		}
3013 		/*
3014 		 * We lost the race, start over.  We have to drop our
3015 		 * critical section to free the bucket.
3016 		 */
3017 		critical_exit();
3018 		bucket_free(zone, bucket, udata);
3019 		goto zfree_restart;
3020 	}
3021 
3022 	/*
3023 	 * If nothing else caught this, we'll just do an internal free.
3024 	 */
3025 zfree_item:
3026 	zone_free_item(zone, item, udata, SKIP_DTOR);
3027 
3028 	return;
3029 }
3030 
3031 void
3032 uma_zfree_domain(uma_zone_t zone, void *item, void *udata)
3033 {
3034 
3035 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
3036 	random_harvest_fast_uma(&zone, sizeof(zone), 1, RANDOM_UMA);
3037 
3038 	CTR2(KTR_UMA, "uma_zfree_domain thread %x zone %s", curthread,
3039 	    zone->uz_name);
3040 
3041 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
3042 	    ("uma_zfree_domain: called with spinlock or critical section held"));
3043 
3044         /* uma_zfree(..., NULL) does nothing, to match free(9). */
3045         if (item == NULL)
3046                 return;
3047 	zone_free_item(zone, item, udata, SKIP_NONE);
3048 }
3049 
3050 static void
3051 slab_free_item(uma_keg_t keg, uma_slab_t slab, void *item)
3052 {
3053 	uma_domain_t dom;
3054 	uint8_t freei;
3055 
3056 	mtx_assert(&keg->uk_lock, MA_OWNED);
3057 	MPASS(keg == slab->us_keg);
3058 
3059 	dom = &keg->uk_domain[slab->us_domain];
3060 
3061 	/* Do we need to remove from any lists? */
3062 	if (slab->us_freecount+1 == keg->uk_ipers) {
3063 		LIST_REMOVE(slab, us_link);
3064 		LIST_INSERT_HEAD(&dom->ud_free_slab, slab, us_link);
3065 	} else if (slab->us_freecount == 0) {
3066 		LIST_REMOVE(slab, us_link);
3067 		LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
3068 	}
3069 
3070 	/* Slab management. */
3071 	freei = ((uintptr_t)item - (uintptr_t)slab->us_data) / keg->uk_rsize;
3072 	BIT_SET(SLAB_SETSIZE, freei, &slab->us_free);
3073 	slab->us_freecount++;
3074 
3075 	/* Keg statistics. */
3076 	keg->uk_free++;
3077 }
3078 
3079 static void
3080 zone_release(uma_zone_t zone, void **bucket, int cnt)
3081 {
3082 	void *item;
3083 	uma_slab_t slab;
3084 	uma_keg_t keg;
3085 	uint8_t *mem;
3086 	int clearfull;
3087 	int i;
3088 
3089 	clearfull = 0;
3090 	keg = zone_first_keg(zone);
3091 	KEG_LOCK(keg);
3092 	for (i = 0; i < cnt; i++) {
3093 		item = bucket[i];
3094 		if (!(zone->uz_flags & UMA_ZONE_VTOSLAB)) {
3095 			mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
3096 			if (zone->uz_flags & UMA_ZONE_HASH) {
3097 				slab = hash_sfind(&keg->uk_hash, mem);
3098 			} else {
3099 				mem += keg->uk_pgoff;
3100 				slab = (uma_slab_t)mem;
3101 			}
3102 		} else {
3103 			slab = vtoslab((vm_offset_t)item);
3104 			if (slab->us_keg != keg) {
3105 				KEG_UNLOCK(keg);
3106 				keg = slab->us_keg;
3107 				KEG_LOCK(keg);
3108 			}
3109 		}
3110 		slab_free_item(keg, slab, item);
3111 		if (keg->uk_flags & UMA_ZFLAG_FULL) {
3112 			if (keg->uk_pages < keg->uk_maxpages) {
3113 				keg->uk_flags &= ~UMA_ZFLAG_FULL;
3114 				clearfull = 1;
3115 			}
3116 
3117 			/*
3118 			 * We can handle one more allocation. Since we're
3119 			 * clearing ZFLAG_FULL, wake up all procs blocked
3120 			 * on pages. This should be uncommon, so keeping this
3121 			 * simple for now (rather than adding count of blocked
3122 			 * threads etc).
3123 			 */
3124 			wakeup(keg);
3125 		}
3126 	}
3127 	KEG_UNLOCK(keg);
3128 	if (clearfull) {
3129 		ZONE_LOCK(zone);
3130 		zone->uz_flags &= ~UMA_ZFLAG_FULL;
3131 		wakeup(zone);
3132 		ZONE_UNLOCK(zone);
3133 	}
3134 
3135 }
3136 
3137 /*
3138  * Frees a single item to any zone.
3139  *
3140  * Arguments:
3141  *	zone   The zone to free to
3142  *	item   The item we're freeing
3143  *	udata  User supplied data for the dtor
3144  *	skip   Skip dtors and finis
3145  */
3146 static void
3147 zone_free_item(uma_zone_t zone, void *item, void *udata, enum zfreeskip skip)
3148 {
3149 
3150 #ifdef INVARIANTS
3151 	if (skip == SKIP_NONE) {
3152 		if (zone->uz_flags & UMA_ZONE_MALLOC)
3153 			uma_dbg_free(zone, udata, item);
3154 		else
3155 			uma_dbg_free(zone, NULL, item);
3156 	}
3157 #endif
3158 	if (skip < SKIP_DTOR && zone->uz_dtor)
3159 		zone->uz_dtor(item, zone->uz_size, udata);
3160 
3161 	if (skip < SKIP_FINI && zone->uz_fini)
3162 		zone->uz_fini(item, zone->uz_size);
3163 
3164 	atomic_add_long(&zone->uz_frees, 1);
3165 	zone->uz_release(zone->uz_arg, &item, 1);
3166 }
3167 
3168 /* See uma.h */
3169 int
3170 uma_zone_set_max(uma_zone_t zone, int nitems)
3171 {
3172 	uma_keg_t keg;
3173 
3174 	keg = zone_first_keg(zone);
3175 	if (keg == NULL)
3176 		return (0);
3177 	KEG_LOCK(keg);
3178 	keg->uk_maxpages = (nitems / keg->uk_ipers) * keg->uk_ppera;
3179 	if (keg->uk_maxpages * keg->uk_ipers < nitems)
3180 		keg->uk_maxpages += keg->uk_ppera;
3181 	nitems = (keg->uk_maxpages / keg->uk_ppera) * keg->uk_ipers;
3182 	KEG_UNLOCK(keg);
3183 
3184 	return (nitems);
3185 }
3186 
3187 /* See uma.h */
3188 int
3189 uma_zone_get_max(uma_zone_t zone)
3190 {
3191 	int nitems;
3192 	uma_keg_t keg;
3193 
3194 	keg = zone_first_keg(zone);
3195 	if (keg == NULL)
3196 		return (0);
3197 	KEG_LOCK(keg);
3198 	nitems = (keg->uk_maxpages / keg->uk_ppera) * keg->uk_ipers;
3199 	KEG_UNLOCK(keg);
3200 
3201 	return (nitems);
3202 }
3203 
3204 /* See uma.h */
3205 void
3206 uma_zone_set_warning(uma_zone_t zone, const char *warning)
3207 {
3208 
3209 	ZONE_LOCK(zone);
3210 	zone->uz_warning = warning;
3211 	ZONE_UNLOCK(zone);
3212 }
3213 
3214 /* See uma.h */
3215 void
3216 uma_zone_set_maxaction(uma_zone_t zone, uma_maxaction_t maxaction)
3217 {
3218 
3219 	ZONE_LOCK(zone);
3220 	TASK_INIT(&zone->uz_maxaction, 0, (task_fn_t *)maxaction, zone);
3221 	ZONE_UNLOCK(zone);
3222 }
3223 
3224 /* See uma.h */
3225 int
3226 uma_zone_get_cur(uma_zone_t zone)
3227 {
3228 	int64_t nitems;
3229 	u_int i;
3230 
3231 	ZONE_LOCK(zone);
3232 	nitems = zone->uz_allocs - zone->uz_frees;
3233 	CPU_FOREACH(i) {
3234 		/*
3235 		 * See the comment in sysctl_vm_zone_stats() regarding the
3236 		 * safety of accessing the per-cpu caches. With the zone lock
3237 		 * held, it is safe, but can potentially result in stale data.
3238 		 */
3239 		nitems += zone->uz_cpu[i].uc_allocs -
3240 		    zone->uz_cpu[i].uc_frees;
3241 	}
3242 	ZONE_UNLOCK(zone);
3243 
3244 	return (nitems < 0 ? 0 : nitems);
3245 }
3246 
3247 /* See uma.h */
3248 void
3249 uma_zone_set_init(uma_zone_t zone, uma_init uminit)
3250 {
3251 	uma_keg_t keg;
3252 
3253 	keg = zone_first_keg(zone);
3254 	KASSERT(keg != NULL, ("uma_zone_set_init: Invalid zone type"));
3255 	KEG_LOCK(keg);
3256 	KASSERT(keg->uk_pages == 0,
3257 	    ("uma_zone_set_init on non-empty keg"));
3258 	keg->uk_init = uminit;
3259 	KEG_UNLOCK(keg);
3260 }
3261 
3262 /* See uma.h */
3263 void
3264 uma_zone_set_fini(uma_zone_t zone, uma_fini fini)
3265 {
3266 	uma_keg_t keg;
3267 
3268 	keg = zone_first_keg(zone);
3269 	KASSERT(keg != NULL, ("uma_zone_set_fini: Invalid zone type"));
3270 	KEG_LOCK(keg);
3271 	KASSERT(keg->uk_pages == 0,
3272 	    ("uma_zone_set_fini on non-empty keg"));
3273 	keg->uk_fini = fini;
3274 	KEG_UNLOCK(keg);
3275 }
3276 
3277 /* See uma.h */
3278 void
3279 uma_zone_set_zinit(uma_zone_t zone, uma_init zinit)
3280 {
3281 
3282 	ZONE_LOCK(zone);
3283 	KASSERT(zone_first_keg(zone)->uk_pages == 0,
3284 	    ("uma_zone_set_zinit on non-empty keg"));
3285 	zone->uz_init = zinit;
3286 	ZONE_UNLOCK(zone);
3287 }
3288 
3289 /* See uma.h */
3290 void
3291 uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini)
3292 {
3293 
3294 	ZONE_LOCK(zone);
3295 	KASSERT(zone_first_keg(zone)->uk_pages == 0,
3296 	    ("uma_zone_set_zfini on non-empty keg"));
3297 	zone->uz_fini = zfini;
3298 	ZONE_UNLOCK(zone);
3299 }
3300 
3301 /* See uma.h */
3302 /* XXX uk_freef is not actually used with the zone locked */
3303 void
3304 uma_zone_set_freef(uma_zone_t zone, uma_free freef)
3305 {
3306 	uma_keg_t keg;
3307 
3308 	keg = zone_first_keg(zone);
3309 	KASSERT(keg != NULL, ("uma_zone_set_freef: Invalid zone type"));
3310 	KEG_LOCK(keg);
3311 	keg->uk_freef = freef;
3312 	KEG_UNLOCK(keg);
3313 }
3314 
3315 /* See uma.h */
3316 /* XXX uk_allocf is not actually used with the zone locked */
3317 void
3318 uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf)
3319 {
3320 	uma_keg_t keg;
3321 
3322 	keg = zone_first_keg(zone);
3323 	KEG_LOCK(keg);
3324 	keg->uk_allocf = allocf;
3325 	KEG_UNLOCK(keg);
3326 }
3327 
3328 /* See uma.h */
3329 void
3330 uma_zone_reserve(uma_zone_t zone, int items)
3331 {
3332 	uma_keg_t keg;
3333 
3334 	keg = zone_first_keg(zone);
3335 	if (keg == NULL)
3336 		return;
3337 	KEG_LOCK(keg);
3338 	keg->uk_reserve = items;
3339 	KEG_UNLOCK(keg);
3340 
3341 	return;
3342 }
3343 
3344 /* See uma.h */
3345 int
3346 uma_zone_reserve_kva(uma_zone_t zone, int count)
3347 {
3348 	uma_keg_t keg;
3349 	vm_offset_t kva;
3350 	u_int pages;
3351 
3352 	keg = zone_first_keg(zone);
3353 	if (keg == NULL)
3354 		return (0);
3355 	pages = count / keg->uk_ipers;
3356 
3357 	if (pages * keg->uk_ipers < count)
3358 		pages++;
3359 	pages *= keg->uk_ppera;
3360 
3361 #ifdef UMA_MD_SMALL_ALLOC
3362 	if (keg->uk_ppera > 1) {
3363 #else
3364 	if (1) {
3365 #endif
3366 		kva = kva_alloc((vm_size_t)pages * PAGE_SIZE);
3367 		if (kva == 0)
3368 			return (0);
3369 	} else
3370 		kva = 0;
3371 	KEG_LOCK(keg);
3372 	keg->uk_kva = kva;
3373 	keg->uk_offset = 0;
3374 	keg->uk_maxpages = pages;
3375 #ifdef UMA_MD_SMALL_ALLOC
3376 	keg->uk_allocf = (keg->uk_ppera > 1) ? noobj_alloc : uma_small_alloc;
3377 #else
3378 	keg->uk_allocf = noobj_alloc;
3379 #endif
3380 	keg->uk_flags |= UMA_ZONE_NOFREE;
3381 	KEG_UNLOCK(keg);
3382 
3383 	return (1);
3384 }
3385 
3386 /* See uma.h */
3387 void
3388 uma_prealloc(uma_zone_t zone, int items)
3389 {
3390 	uma_domain_t dom;
3391 	uma_slab_t slab;
3392 	uma_keg_t keg;
3393 	int domain, slabs;
3394 
3395 	keg = zone_first_keg(zone);
3396 	if (keg == NULL)
3397 		return;
3398 	KEG_LOCK(keg);
3399 	slabs = items / keg->uk_ipers;
3400 	domain = 0;
3401 	if (slabs * keg->uk_ipers < items)
3402 		slabs++;
3403 	while (slabs > 0) {
3404 		slab = keg_alloc_slab(keg, zone, domain, M_WAITOK);
3405 		if (slab == NULL)
3406 			break;
3407 		MPASS(slab->us_keg == keg);
3408 		dom = &keg->uk_domain[slab->us_domain];
3409 		LIST_INSERT_HEAD(&dom->ud_free_slab, slab, us_link);
3410 		slabs--;
3411 		domain = (domain + 1) % vm_ndomains;
3412 	}
3413 	KEG_UNLOCK(keg);
3414 }
3415 
3416 /* See uma.h */
3417 static void
3418 uma_reclaim_locked(bool kmem_danger)
3419 {
3420 
3421 	CTR0(KTR_UMA, "UMA: vm asked us to release pages!");
3422 	sx_assert(&uma_drain_lock, SA_XLOCKED);
3423 	bucket_enable();
3424 	zone_foreach(zone_drain);
3425 	if (vm_page_count_min() || kmem_danger) {
3426 		cache_drain_safe(NULL);
3427 		zone_foreach(zone_drain);
3428 	}
3429 	/*
3430 	 * Some slabs may have been freed but this zone will be visited early
3431 	 * we visit again so that we can free pages that are empty once other
3432 	 * zones are drained.  We have to do the same for buckets.
3433 	 */
3434 	zone_drain(slabzone);
3435 	bucket_zone_drain();
3436 }
3437 
3438 void
3439 uma_reclaim(void)
3440 {
3441 
3442 	sx_xlock(&uma_drain_lock);
3443 	uma_reclaim_locked(false);
3444 	sx_xunlock(&uma_drain_lock);
3445 }
3446 
3447 static volatile int uma_reclaim_needed;
3448 
3449 void
3450 uma_reclaim_wakeup(void)
3451 {
3452 
3453 	if (atomic_fetchadd_int(&uma_reclaim_needed, 1) == 0)
3454 		wakeup(uma_reclaim);
3455 }
3456 
3457 void
3458 uma_reclaim_worker(void *arg __unused)
3459 {
3460 
3461 	for (;;) {
3462 		sx_xlock(&uma_drain_lock);
3463 		while (atomic_load_int(&uma_reclaim_needed) == 0)
3464 			sx_sleep(uma_reclaim, &uma_drain_lock, PVM, "umarcl",
3465 			    hz);
3466 		sx_xunlock(&uma_drain_lock);
3467 		EVENTHANDLER_INVOKE(vm_lowmem, VM_LOW_KMEM);
3468 		sx_xlock(&uma_drain_lock);
3469 		uma_reclaim_locked(true);
3470 		atomic_store_int(&uma_reclaim_needed, 0);
3471 		sx_xunlock(&uma_drain_lock);
3472 		/* Don't fire more than once per-second. */
3473 		pause("umarclslp", hz);
3474 	}
3475 }
3476 
3477 /* See uma.h */
3478 int
3479 uma_zone_exhausted(uma_zone_t zone)
3480 {
3481 	int full;
3482 
3483 	ZONE_LOCK(zone);
3484 	full = (zone->uz_flags & UMA_ZFLAG_FULL);
3485 	ZONE_UNLOCK(zone);
3486 	return (full);
3487 }
3488 
3489 int
3490 uma_zone_exhausted_nolock(uma_zone_t zone)
3491 {
3492 	return (zone->uz_flags & UMA_ZFLAG_FULL);
3493 }
3494 
3495 void *
3496 uma_large_malloc_domain(vm_size_t size, int domain, int wait)
3497 {
3498 	vm_offset_t addr;
3499 	uma_slab_t slab;
3500 
3501 	slab = zone_alloc_item(slabzone, NULL, domain, wait);
3502 	if (slab == NULL)
3503 		return (NULL);
3504 	if (domain == UMA_ANYDOMAIN)
3505 		addr = kmem_malloc(kernel_arena, size, wait);
3506 	else
3507 		addr = kmem_malloc_domain(domain, size, wait);
3508 	if (addr != 0) {
3509 		vsetslab(addr, slab);
3510 		slab->us_data = (void *)addr;
3511 		slab->us_flags = UMA_SLAB_KERNEL | UMA_SLAB_MALLOC;
3512 		slab->us_size = size;
3513 		slab->us_domain = vm_phys_domain(PHYS_TO_VM_PAGE(
3514 		    pmap_kextract(addr)));
3515 		uma_total_inc(size);
3516 	} else {
3517 		zone_free_item(slabzone, slab, NULL, SKIP_NONE);
3518 	}
3519 
3520 	return ((void *)addr);
3521 }
3522 
3523 void *
3524 uma_large_malloc(vm_size_t size, int wait)
3525 {
3526 
3527 	return uma_large_malloc_domain(size, UMA_ANYDOMAIN, wait);
3528 }
3529 
3530 void
3531 uma_large_free(uma_slab_t slab)
3532 {
3533 
3534 	KASSERT((slab->us_flags & UMA_SLAB_KERNEL) != 0,
3535 	    ("uma_large_free:  Memory not allocated with uma_large_malloc."));
3536 	kmem_free(kernel_arena, (vm_offset_t)slab->us_data, slab->us_size);
3537 	uma_total_dec(slab->us_size);
3538 	zone_free_item(slabzone, slab, NULL, SKIP_NONE);
3539 }
3540 
3541 static void
3542 uma_zero_item(void *item, uma_zone_t zone)
3543 {
3544 	int i;
3545 
3546 	if (zone->uz_flags & UMA_ZONE_PCPU) {
3547 		CPU_FOREACH(i)
3548 			bzero(zpcpu_get_cpu(item, i), zone->uz_size);
3549 	} else
3550 		bzero(item, zone->uz_size);
3551 }
3552 
3553 unsigned long
3554 uma_limit(void)
3555 {
3556 
3557 	return (uma_kmem_limit);
3558 }
3559 
3560 void
3561 uma_set_limit(unsigned long limit)
3562 {
3563 
3564 	uma_kmem_limit = limit;
3565 }
3566 
3567 unsigned long
3568 uma_size(void)
3569 {
3570 
3571 	return (uma_kmem_total);
3572 }
3573 
3574 long
3575 uma_avail(void)
3576 {
3577 
3578 	return (uma_kmem_limit - uma_kmem_total);
3579 }
3580 
3581 void
3582 uma_print_stats(void)
3583 {
3584 	zone_foreach(uma_print_zone);
3585 }
3586 
3587 static void
3588 slab_print(uma_slab_t slab)
3589 {
3590 	printf("slab: keg %p, data %p, freecount %d\n",
3591 		slab->us_keg, slab->us_data, slab->us_freecount);
3592 }
3593 
3594 static void
3595 cache_print(uma_cache_t cache)
3596 {
3597 	printf("alloc: %p(%d), free: %p(%d)\n",
3598 		cache->uc_allocbucket,
3599 		cache->uc_allocbucket?cache->uc_allocbucket->ub_cnt:0,
3600 		cache->uc_freebucket,
3601 		cache->uc_freebucket?cache->uc_freebucket->ub_cnt:0);
3602 }
3603 
3604 static void
3605 uma_print_keg(uma_keg_t keg)
3606 {
3607 	uma_domain_t dom;
3608 	uma_slab_t slab;
3609 	int i;
3610 
3611 	printf("keg: %s(%p) size %d(%d) flags %#x ipers %d ppera %d "
3612 	    "out %d free %d limit %d\n",
3613 	    keg->uk_name, keg, keg->uk_size, keg->uk_rsize, keg->uk_flags,
3614 	    keg->uk_ipers, keg->uk_ppera,
3615 	    (keg->uk_pages / keg->uk_ppera) * keg->uk_ipers - keg->uk_free,
3616 	    keg->uk_free, (keg->uk_maxpages / keg->uk_ppera) * keg->uk_ipers);
3617 	for (i = 0; i < vm_ndomains; i++) {
3618 		dom = &keg->uk_domain[i];
3619 		printf("Part slabs:\n");
3620 		LIST_FOREACH(slab, &dom->ud_part_slab, us_link)
3621 			slab_print(slab);
3622 		printf("Free slabs:\n");
3623 		LIST_FOREACH(slab, &dom->ud_free_slab, us_link)
3624 			slab_print(slab);
3625 		printf("Full slabs:\n");
3626 		LIST_FOREACH(slab, &dom->ud_full_slab, us_link)
3627 			slab_print(slab);
3628 	}
3629 }
3630 
3631 void
3632 uma_print_zone(uma_zone_t zone)
3633 {
3634 	uma_cache_t cache;
3635 	uma_klink_t kl;
3636 	int i;
3637 
3638 	printf("zone: %s(%p) size %d flags %#x\n",
3639 	    zone->uz_name, zone, zone->uz_size, zone->uz_flags);
3640 	LIST_FOREACH(kl, &zone->uz_kegs, kl_link)
3641 		uma_print_keg(kl->kl_keg);
3642 	CPU_FOREACH(i) {
3643 		cache = &zone->uz_cpu[i];
3644 		printf("CPU %d Cache:\n", i);
3645 		cache_print(cache);
3646 	}
3647 }
3648 
3649 #ifdef DDB
3650 /*
3651  * Generate statistics across both the zone and its per-cpu cache's.  Return
3652  * desired statistics if the pointer is non-NULL for that statistic.
3653  *
3654  * Note: does not update the zone statistics, as it can't safely clear the
3655  * per-CPU cache statistic.
3656  *
3657  * XXXRW: Following the uc_allocbucket and uc_freebucket pointers here isn't
3658  * safe from off-CPU; we should modify the caches to track this information
3659  * directly so that we don't have to.
3660  */
3661 static void
3662 uma_zone_sumstat(uma_zone_t z, int *cachefreep, uint64_t *allocsp,
3663     uint64_t *freesp, uint64_t *sleepsp)
3664 {
3665 	uma_cache_t cache;
3666 	uint64_t allocs, frees, sleeps;
3667 	int cachefree, cpu;
3668 
3669 	allocs = frees = sleeps = 0;
3670 	cachefree = 0;
3671 	CPU_FOREACH(cpu) {
3672 		cache = &z->uz_cpu[cpu];
3673 		if (cache->uc_allocbucket != NULL)
3674 			cachefree += cache->uc_allocbucket->ub_cnt;
3675 		if (cache->uc_freebucket != NULL)
3676 			cachefree += cache->uc_freebucket->ub_cnt;
3677 		allocs += cache->uc_allocs;
3678 		frees += cache->uc_frees;
3679 	}
3680 	allocs += z->uz_allocs;
3681 	frees += z->uz_frees;
3682 	sleeps += z->uz_sleeps;
3683 	if (cachefreep != NULL)
3684 		*cachefreep = cachefree;
3685 	if (allocsp != NULL)
3686 		*allocsp = allocs;
3687 	if (freesp != NULL)
3688 		*freesp = frees;
3689 	if (sleepsp != NULL)
3690 		*sleepsp = sleeps;
3691 }
3692 #endif /* DDB */
3693 
3694 static int
3695 sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS)
3696 {
3697 	uma_keg_t kz;
3698 	uma_zone_t z;
3699 	int count;
3700 
3701 	count = 0;
3702 	rw_rlock(&uma_rwlock);
3703 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3704 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
3705 			count++;
3706 	}
3707 	rw_runlock(&uma_rwlock);
3708 	return (sysctl_handle_int(oidp, &count, 0, req));
3709 }
3710 
3711 static int
3712 sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS)
3713 {
3714 	struct uma_stream_header ush;
3715 	struct uma_type_header uth;
3716 	struct uma_percpu_stat *ups;
3717 	uma_bucket_t bucket;
3718 	uma_zone_domain_t zdom;
3719 	struct sbuf sbuf;
3720 	uma_cache_t cache;
3721 	uma_klink_t kl;
3722 	uma_keg_t kz;
3723 	uma_zone_t z;
3724 	uma_keg_t k;
3725 	int count, error, i;
3726 
3727 	error = sysctl_wire_old_buffer(req, 0);
3728 	if (error != 0)
3729 		return (error);
3730 	sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
3731 	sbuf_clear_flags(&sbuf, SBUF_INCLUDENUL);
3732 	ups = malloc((mp_maxid + 1) * sizeof(*ups), M_TEMP, M_WAITOK);
3733 
3734 	count = 0;
3735 	rw_rlock(&uma_rwlock);
3736 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3737 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
3738 			count++;
3739 	}
3740 
3741 	/*
3742 	 * Insert stream header.
3743 	 */
3744 	bzero(&ush, sizeof(ush));
3745 	ush.ush_version = UMA_STREAM_VERSION;
3746 	ush.ush_maxcpus = (mp_maxid + 1);
3747 	ush.ush_count = count;
3748 	(void)sbuf_bcat(&sbuf, &ush, sizeof(ush));
3749 
3750 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3751 		LIST_FOREACH(z, &kz->uk_zones, uz_link) {
3752 			bzero(&uth, sizeof(uth));
3753 			ZONE_LOCK(z);
3754 			strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
3755 			uth.uth_align = kz->uk_align;
3756 			uth.uth_size = kz->uk_size;
3757 			uth.uth_rsize = kz->uk_rsize;
3758 			LIST_FOREACH(kl, &z->uz_kegs, kl_link) {
3759 				k = kl->kl_keg;
3760 				uth.uth_maxpages += k->uk_maxpages;
3761 				uth.uth_pages += k->uk_pages;
3762 				uth.uth_keg_free += k->uk_free;
3763 				uth.uth_limit = (k->uk_maxpages / k->uk_ppera)
3764 				    * k->uk_ipers;
3765 			}
3766 
3767 			/*
3768 			 * A zone is secondary is it is not the first entry
3769 			 * on the keg's zone list.
3770 			 */
3771 			if ((z->uz_flags & UMA_ZONE_SECONDARY) &&
3772 			    (LIST_FIRST(&kz->uk_zones) != z))
3773 				uth.uth_zone_flags = UTH_ZONE_SECONDARY;
3774 
3775 			for (i = 0; i < vm_ndomains; i++) {
3776 				zdom = &z->uz_domain[i];
3777 				LIST_FOREACH(bucket, &zdom->uzd_buckets,
3778 				    ub_link)
3779 					uth.uth_zone_free += bucket->ub_cnt;
3780 			}
3781 			uth.uth_allocs = z->uz_allocs;
3782 			uth.uth_frees = z->uz_frees;
3783 			uth.uth_fails = z->uz_fails;
3784 			uth.uth_sleeps = z->uz_sleeps;
3785 			/*
3786 			 * While it is not normally safe to access the cache
3787 			 * bucket pointers while not on the CPU that owns the
3788 			 * cache, we only allow the pointers to be exchanged
3789 			 * without the zone lock held, not invalidated, so
3790 			 * accept the possible race associated with bucket
3791 			 * exchange during monitoring.
3792 			 */
3793 			for (i = 0; i < mp_maxid + 1; i++) {
3794 				bzero(&ups[i], sizeof(*ups));
3795 				if (kz->uk_flags & UMA_ZFLAG_INTERNAL ||
3796 				    CPU_ABSENT(i))
3797 					continue;
3798 				cache = &z->uz_cpu[i];
3799 				if (cache->uc_allocbucket != NULL)
3800 					ups[i].ups_cache_free +=
3801 					    cache->uc_allocbucket->ub_cnt;
3802 				if (cache->uc_freebucket != NULL)
3803 					ups[i].ups_cache_free +=
3804 					    cache->uc_freebucket->ub_cnt;
3805 				ups[i].ups_allocs = cache->uc_allocs;
3806 				ups[i].ups_frees = cache->uc_frees;
3807 			}
3808 			ZONE_UNLOCK(z);
3809 			(void)sbuf_bcat(&sbuf, &uth, sizeof(uth));
3810 			for (i = 0; i < mp_maxid + 1; i++)
3811 				(void)sbuf_bcat(&sbuf, &ups[i], sizeof(ups[i]));
3812 		}
3813 	}
3814 	rw_runlock(&uma_rwlock);
3815 	error = sbuf_finish(&sbuf);
3816 	sbuf_delete(&sbuf);
3817 	free(ups, M_TEMP);
3818 	return (error);
3819 }
3820 
3821 int
3822 sysctl_handle_uma_zone_max(SYSCTL_HANDLER_ARGS)
3823 {
3824 	uma_zone_t zone = *(uma_zone_t *)arg1;
3825 	int error, max;
3826 
3827 	max = uma_zone_get_max(zone);
3828 	error = sysctl_handle_int(oidp, &max, 0, req);
3829 	if (error || !req->newptr)
3830 		return (error);
3831 
3832 	uma_zone_set_max(zone, max);
3833 
3834 	return (0);
3835 }
3836 
3837 int
3838 sysctl_handle_uma_zone_cur(SYSCTL_HANDLER_ARGS)
3839 {
3840 	uma_zone_t zone = *(uma_zone_t *)arg1;
3841 	int cur;
3842 
3843 	cur = uma_zone_get_cur(zone);
3844 	return (sysctl_handle_int(oidp, &cur, 0, req));
3845 }
3846 
3847 #ifdef INVARIANTS
3848 static uma_slab_t
3849 uma_dbg_getslab(uma_zone_t zone, void *item)
3850 {
3851 	uma_slab_t slab;
3852 	uma_keg_t keg;
3853 	uint8_t *mem;
3854 
3855 	mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
3856 	if (zone->uz_flags & UMA_ZONE_VTOSLAB) {
3857 		slab = vtoslab((vm_offset_t)mem);
3858 	} else {
3859 		/*
3860 		 * It is safe to return the slab here even though the
3861 		 * zone is unlocked because the item's allocation state
3862 		 * essentially holds a reference.
3863 		 */
3864 		ZONE_LOCK(zone);
3865 		keg = LIST_FIRST(&zone->uz_kegs)->kl_keg;
3866 		if (keg->uk_flags & UMA_ZONE_HASH)
3867 			slab = hash_sfind(&keg->uk_hash, mem);
3868 		else
3869 			slab = (uma_slab_t)(mem + keg->uk_pgoff);
3870 		ZONE_UNLOCK(zone);
3871 	}
3872 
3873 	return (slab);
3874 }
3875 
3876 /*
3877  * Set up the slab's freei data such that uma_dbg_free can function.
3878  *
3879  */
3880 static void
3881 uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item)
3882 {
3883 	uma_keg_t keg;
3884 	int freei;
3885 
3886 	if (zone_first_keg(zone) == NULL)
3887 		return;
3888 	if (slab == NULL) {
3889 		slab = uma_dbg_getslab(zone, item);
3890 		if (slab == NULL)
3891 			panic("uma: item %p did not belong to zone %s\n",
3892 			    item, zone->uz_name);
3893 	}
3894 	keg = slab->us_keg;
3895 	freei = ((uintptr_t)item - (uintptr_t)slab->us_data) / keg->uk_rsize;
3896 
3897 	if (BIT_ISSET(SLAB_SETSIZE, freei, &slab->us_debugfree))
3898 		panic("Duplicate alloc of %p from zone %p(%s) slab %p(%d)\n",
3899 		    item, zone, zone->uz_name, slab, freei);
3900 	BIT_SET_ATOMIC(SLAB_SETSIZE, freei, &slab->us_debugfree);
3901 
3902 	return;
3903 }
3904 
3905 /*
3906  * Verifies freed addresses.  Checks for alignment, valid slab membership
3907  * and duplicate frees.
3908  *
3909  */
3910 static void
3911 uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item)
3912 {
3913 	uma_keg_t keg;
3914 	int freei;
3915 
3916 	if (zone_first_keg(zone) == NULL)
3917 		return;
3918 	if (slab == NULL) {
3919 		slab = uma_dbg_getslab(zone, item);
3920 		if (slab == NULL)
3921 			panic("uma: Freed item %p did not belong to zone %s\n",
3922 			    item, zone->uz_name);
3923 	}
3924 	keg = slab->us_keg;
3925 	freei = ((uintptr_t)item - (uintptr_t)slab->us_data) / keg->uk_rsize;
3926 
3927 	if (freei >= keg->uk_ipers)
3928 		panic("Invalid free of %p from zone %p(%s) slab %p(%d)\n",
3929 		    item, zone, zone->uz_name, slab, freei);
3930 
3931 	if (((freei * keg->uk_rsize) + slab->us_data) != item)
3932 		panic("Unaligned free of %p from zone %p(%s) slab %p(%d)\n",
3933 		    item, zone, zone->uz_name, slab, freei);
3934 
3935 	if (!BIT_ISSET(SLAB_SETSIZE, freei, &slab->us_debugfree))
3936 		panic("Duplicate free of %p from zone %p(%s) slab %p(%d)\n",
3937 		    item, zone, zone->uz_name, slab, freei);
3938 
3939 	BIT_CLR_ATOMIC(SLAB_SETSIZE, freei, &slab->us_debugfree);
3940 }
3941 #endif /* INVARIANTS */
3942 
3943 #ifdef DDB
3944 DB_SHOW_COMMAND(uma, db_show_uma)
3945 {
3946 	uma_bucket_t bucket;
3947 	uma_keg_t kz;
3948 	uma_zone_t z;
3949 	uma_zone_domain_t zdom;
3950 	uint64_t allocs, frees, sleeps;
3951 	int cachefree, i;
3952 
3953 	db_printf("%18s %8s %8s %8s %12s %8s %8s\n", "Zone", "Size", "Used",
3954 	    "Free", "Requests", "Sleeps", "Bucket");
3955 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3956 		LIST_FOREACH(z, &kz->uk_zones, uz_link) {
3957 			if (kz->uk_flags & UMA_ZFLAG_INTERNAL) {
3958 				allocs = z->uz_allocs;
3959 				frees = z->uz_frees;
3960 				sleeps = z->uz_sleeps;
3961 				cachefree = 0;
3962 			} else
3963 				uma_zone_sumstat(z, &cachefree, &allocs,
3964 				    &frees, &sleeps);
3965 			if (!((z->uz_flags & UMA_ZONE_SECONDARY) &&
3966 			    (LIST_FIRST(&kz->uk_zones) != z)))
3967 				cachefree += kz->uk_free;
3968 			for (i = 0; i < vm_ndomains; i++) {
3969 				zdom = &z->uz_domain[i];
3970 				LIST_FOREACH(bucket, &zdom->uzd_buckets,
3971 				    ub_link)
3972 					cachefree += bucket->ub_cnt;
3973 			}
3974 			db_printf("%18s %8ju %8jd %8d %12ju %8ju %8u\n",
3975 			    z->uz_name, (uintmax_t)kz->uk_size,
3976 			    (intmax_t)(allocs - frees), cachefree,
3977 			    (uintmax_t)allocs, sleeps, z->uz_count);
3978 			if (db_pager_quit)
3979 				return;
3980 		}
3981 	}
3982 }
3983 
3984 DB_SHOW_COMMAND(umacache, db_show_umacache)
3985 {
3986 	uma_bucket_t bucket;
3987 	uma_zone_t z;
3988 	uma_zone_domain_t zdom;
3989 	uint64_t allocs, frees;
3990 	int cachefree, i;
3991 
3992 	db_printf("%18s %8s %8s %8s %12s %8s\n", "Zone", "Size", "Used", "Free",
3993 	    "Requests", "Bucket");
3994 	LIST_FOREACH(z, &uma_cachezones, uz_link) {
3995 		uma_zone_sumstat(z, &cachefree, &allocs, &frees, NULL);
3996 		for (i = 0; i < vm_ndomains; i++) {
3997 			zdom = &z->uz_domain[i];
3998 			LIST_FOREACH(bucket, &zdom->uzd_buckets, ub_link)
3999 				cachefree += bucket->ub_cnt;
4000 		}
4001 		db_printf("%18s %8ju %8jd %8d %12ju %8u\n",
4002 		    z->uz_name, (uintmax_t)z->uz_size,
4003 		    (intmax_t)(allocs - frees), cachefree,
4004 		    (uintmax_t)allocs, z->uz_count);
4005 		if (db_pager_quit)
4006 			return;
4007 	}
4008 }
4009 #endif	/* DDB */
4010