xref: /freebsd/sys/vm/uma_core.c (revision 88640c0e8b6f503426cce9ea1337098c241d3801)
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/domainset.h>
63 #include <sys/eventhandler.h>
64 #include <sys/kernel.h>
65 #include <sys/types.h>
66 #include <sys/limits.h>
67 #include <sys/queue.h>
68 #include <sys/malloc.h>
69 #include <sys/ktr.h>
70 #include <sys/lock.h>
71 #include <sys/sysctl.h>
72 #include <sys/mutex.h>
73 #include <sys/proc.h>
74 #include <sys/random.h>
75 #include <sys/rwlock.h>
76 #include <sys/sbuf.h>
77 #include <sys/sched.h>
78 #include <sys/smp.h>
79 #include <sys/taskqueue.h>
80 #include <sys/vmmeter.h>
81 
82 #include <vm/vm.h>
83 #include <vm/vm_domainset.h>
84 #include <vm/vm_object.h>
85 #include <vm/vm_page.h>
86 #include <vm/vm_pageout.h>
87 #include <vm/vm_param.h>
88 #include <vm/vm_phys.h>
89 #include <vm/vm_pagequeue.h>
90 #include <vm/vm_map.h>
91 #include <vm/vm_kern.h>
92 #include <vm/vm_extern.h>
93 #include <vm/uma.h>
94 #include <vm/uma_int.h>
95 #include <vm/uma_dbg.h>
96 
97 #include <ddb/ddb.h>
98 
99 #ifdef DEBUG_MEMGUARD
100 #include <vm/memguard.h>
101 #endif
102 
103 /*
104  * This is the zone and keg from which all zones are spawned.
105  */
106 static uma_zone_t kegs;
107 static uma_zone_t zones;
108 
109 /* This is the zone from which all offpage uma_slab_ts are allocated. */
110 static uma_zone_t slabzone;
111 
112 /*
113  * The initial hash tables come out of this zone so they can be allocated
114  * prior to malloc coming up.
115  */
116 static uma_zone_t hashzone;
117 
118 /* The boot-time adjusted value for cache line alignment. */
119 int uma_align_cache = 64 - 1;
120 
121 static MALLOC_DEFINE(M_UMAHASH, "UMAHash", "UMA Hash Buckets");
122 
123 /*
124  * Are we allowed to allocate buckets?
125  */
126 static int bucketdisable = 1;
127 
128 /* Linked list of all kegs in the system */
129 static LIST_HEAD(,uma_keg) uma_kegs = LIST_HEAD_INITIALIZER(uma_kegs);
130 
131 /* Linked list of all cache-only zones in the system */
132 static LIST_HEAD(,uma_zone) uma_cachezones =
133     LIST_HEAD_INITIALIZER(uma_cachezones);
134 
135 /* This RW lock protects the keg list */
136 static struct rwlock_padalign __exclusive_cache_line uma_rwlock;
137 
138 /*
139  * Pointer and counter to pool of pages, that is preallocated at
140  * startup to bootstrap UMA.
141  */
142 static char *bootmem;
143 static int boot_pages;
144 
145 static struct sx uma_drain_lock;
146 
147 /* kmem soft limit. */
148 static unsigned long uma_kmem_limit = LONG_MAX;
149 static volatile unsigned long uma_kmem_total;
150 
151 /* Is the VM done starting up? */
152 static enum { BOOT_COLD = 0, BOOT_STRAPPED, BOOT_PAGEALLOC, BOOT_BUCKETS,
153     BOOT_RUNNING } booted = BOOT_COLD;
154 
155 /*
156  * This is the handle used to schedule events that need to happen
157  * outside of the allocation fast path.
158  */
159 static struct callout uma_callout;
160 #define	UMA_TIMEOUT	20		/* Seconds for callout interval. */
161 
162 /*
163  * This structure is passed as the zone ctor arg so that I don't have to create
164  * a special allocation function just for zones.
165  */
166 struct uma_zctor_args {
167 	const char *name;
168 	size_t size;
169 	uma_ctor ctor;
170 	uma_dtor dtor;
171 	uma_init uminit;
172 	uma_fini fini;
173 	uma_import import;
174 	uma_release release;
175 	void *arg;
176 	uma_keg_t keg;
177 	int align;
178 	uint32_t flags;
179 };
180 
181 struct uma_kctor_args {
182 	uma_zone_t zone;
183 	size_t size;
184 	uma_init uminit;
185 	uma_fini fini;
186 	int align;
187 	uint32_t flags;
188 };
189 
190 struct uma_bucket_zone {
191 	uma_zone_t	ubz_zone;
192 	char		*ubz_name;
193 	int		ubz_entries;	/* Number of items it can hold. */
194 	int		ubz_maxsize;	/* Maximum allocation size per-item. */
195 };
196 
197 /*
198  * Compute the actual number of bucket entries to pack them in power
199  * of two sizes for more efficient space utilization.
200  */
201 #define	BUCKET_SIZE(n)						\
202     (((sizeof(void *) * (n)) - sizeof(struct uma_bucket)) / sizeof(void *))
203 
204 #define	BUCKET_MAX	BUCKET_SIZE(256)
205 
206 struct uma_bucket_zone bucket_zones[] = {
207 	{ NULL, "4 Bucket", BUCKET_SIZE(4), 4096 },
208 	{ NULL, "6 Bucket", BUCKET_SIZE(6), 3072 },
209 	{ NULL, "8 Bucket", BUCKET_SIZE(8), 2048 },
210 	{ NULL, "12 Bucket", BUCKET_SIZE(12), 1536 },
211 	{ NULL, "16 Bucket", BUCKET_SIZE(16), 1024 },
212 	{ NULL, "32 Bucket", BUCKET_SIZE(32), 512 },
213 	{ NULL, "64 Bucket", BUCKET_SIZE(64), 256 },
214 	{ NULL, "128 Bucket", BUCKET_SIZE(128), 128 },
215 	{ NULL, "256 Bucket", BUCKET_SIZE(256), 64 },
216 	{ NULL, NULL, 0}
217 };
218 
219 /*
220  * Flags and enumerations to be passed to internal functions.
221  */
222 enum zfreeskip {
223 	SKIP_NONE =	0,
224 	SKIP_CNT =	0x00000001,
225 	SKIP_DTOR =	0x00010000,
226 	SKIP_FINI =	0x00020000,
227 };
228 
229 #define	UMA_ANYDOMAIN	-1	/* Special value for domain search. */
230 
231 /* Prototypes.. */
232 
233 int	uma_startup_count(int);
234 void	uma_startup(void *, int);
235 void	uma_startup1(void);
236 void	uma_startup2(void);
237 
238 static void *noobj_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
239 static void *page_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
240 static void *pcpu_page_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
241 static void *startup_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
242 static void page_free(void *, vm_size_t, uint8_t);
243 static void pcpu_page_free(void *, vm_size_t, uint8_t);
244 static uma_slab_t keg_alloc_slab(uma_keg_t, uma_zone_t, int, int);
245 static void cache_drain(uma_zone_t);
246 static void bucket_drain(uma_zone_t, uma_bucket_t);
247 static void bucket_cache_drain(uma_zone_t zone);
248 static int keg_ctor(void *, int, void *, int);
249 static void keg_dtor(void *, int, void *);
250 static int zone_ctor(void *, int, void *, int);
251 static void zone_dtor(void *, int, void *);
252 static int zero_init(void *, int, int);
253 static void keg_small_init(uma_keg_t keg);
254 static void keg_large_init(uma_keg_t keg);
255 static void zone_foreach(void (*zfunc)(uma_zone_t));
256 static void zone_timeout(uma_zone_t zone);
257 static int hash_alloc(struct uma_hash *);
258 static int hash_expand(struct uma_hash *, struct uma_hash *);
259 static void hash_free(struct uma_hash *hash);
260 static void uma_timeout(void *);
261 static void uma_startup3(void);
262 static void *zone_alloc_item(uma_zone_t, void *, int, int);
263 static void *zone_alloc_item_locked(uma_zone_t, void *, int, int);
264 static void zone_free_item(uma_zone_t, void *, void *, enum zfreeskip);
265 static void bucket_enable(void);
266 static void bucket_init(void);
267 static uma_bucket_t bucket_alloc(uma_zone_t zone, void *, int);
268 static void bucket_free(uma_zone_t zone, uma_bucket_t, void *);
269 static void bucket_zone_drain(void);
270 static uma_bucket_t zone_alloc_bucket(uma_zone_t, void *, int, int, int);
271 static uma_slab_t zone_fetch_slab(uma_zone_t, uma_keg_t, int, int);
272 static void *slab_alloc_item(uma_keg_t keg, uma_slab_t slab);
273 static void slab_free_item(uma_zone_t zone, uma_slab_t slab, void *item);
274 static uma_keg_t uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit,
275     uma_fini fini, int align, uint32_t flags);
276 static int zone_import(uma_zone_t, void **, int, int, int);
277 static void zone_release(uma_zone_t, void **, int);
278 static void uma_zero_item(void *, uma_zone_t);
279 
280 void uma_print_zone(uma_zone_t);
281 void uma_print_stats(void);
282 static int sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS);
283 static int sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS);
284 
285 #ifdef INVARIANTS
286 static bool uma_dbg_kskip(uma_keg_t keg, void *mem);
287 static bool uma_dbg_zskip(uma_zone_t zone, void *mem);
288 static void uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item);
289 static void uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item);
290 
291 static SYSCTL_NODE(_vm, OID_AUTO, debug, CTLFLAG_RD, 0,
292     "Memory allocation debugging");
293 
294 static u_int dbg_divisor = 1;
295 SYSCTL_UINT(_vm_debug, OID_AUTO, divisor,
296     CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &dbg_divisor, 0,
297     "Debug & thrash every this item in memory allocator");
298 
299 static counter_u64_t uma_dbg_cnt = EARLY_COUNTER;
300 static counter_u64_t uma_skip_cnt = EARLY_COUNTER;
301 SYSCTL_COUNTER_U64(_vm_debug, OID_AUTO, trashed, CTLFLAG_RD,
302     &uma_dbg_cnt, "memory items debugged");
303 SYSCTL_COUNTER_U64(_vm_debug, OID_AUTO, skipped, CTLFLAG_RD,
304     &uma_skip_cnt, "memory items skipped, not debugged");
305 #endif
306 
307 SYSINIT(uma_startup3, SI_SUB_VM_CONF, SI_ORDER_SECOND, uma_startup3, NULL);
308 
309 SYSCTL_PROC(_vm, OID_AUTO, zone_count, CTLFLAG_RD|CTLTYPE_INT,
310     0, 0, sysctl_vm_zone_count, "I", "Number of UMA zones");
311 
312 SYSCTL_PROC(_vm, OID_AUTO, zone_stats, CTLFLAG_RD|CTLTYPE_STRUCT,
313     0, 0, sysctl_vm_zone_stats, "s,struct uma_type_header", "Zone Stats");
314 
315 static int zone_warnings = 1;
316 SYSCTL_INT(_vm, OID_AUTO, zone_warnings, CTLFLAG_RWTUN, &zone_warnings, 0,
317     "Warn when UMA zones becomes full");
318 
319 /* Adjust bytes under management by UMA. */
320 static inline void
321 uma_total_dec(unsigned long size)
322 {
323 
324 	atomic_subtract_long(&uma_kmem_total, size);
325 }
326 
327 static inline void
328 uma_total_inc(unsigned long size)
329 {
330 
331 	if (atomic_fetchadd_long(&uma_kmem_total, size) > uma_kmem_limit)
332 		uma_reclaim_wakeup();
333 }
334 
335 /*
336  * This routine checks to see whether or not it's safe to enable buckets.
337  */
338 static void
339 bucket_enable(void)
340 {
341 	bucketdisable = vm_page_count_min();
342 }
343 
344 /*
345  * Initialize bucket_zones, the array of zones of buckets of various sizes.
346  *
347  * For each zone, calculate the memory required for each bucket, consisting
348  * of the header and an array of pointers.
349  */
350 static void
351 bucket_init(void)
352 {
353 	struct uma_bucket_zone *ubz;
354 	int size;
355 
356 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++) {
357 		size = roundup(sizeof(struct uma_bucket), sizeof(void *));
358 		size += sizeof(void *) * ubz->ubz_entries;
359 		ubz->ubz_zone = uma_zcreate(ubz->ubz_name, size,
360 		    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR,
361 		    UMA_ZONE_MTXCLASS | UMA_ZFLAG_BUCKET | UMA_ZONE_NUMA);
362 	}
363 }
364 
365 /*
366  * Given a desired number of entries for a bucket, return the zone from which
367  * to allocate the bucket.
368  */
369 static struct uma_bucket_zone *
370 bucket_zone_lookup(int entries)
371 {
372 	struct uma_bucket_zone *ubz;
373 
374 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
375 		if (ubz->ubz_entries >= entries)
376 			return (ubz);
377 	ubz--;
378 	return (ubz);
379 }
380 
381 static int
382 bucket_select(int size)
383 {
384 	struct uma_bucket_zone *ubz;
385 
386 	ubz = &bucket_zones[0];
387 	if (size > ubz->ubz_maxsize)
388 		return MAX((ubz->ubz_maxsize * ubz->ubz_entries) / size, 1);
389 
390 	for (; ubz->ubz_entries != 0; ubz++)
391 		if (ubz->ubz_maxsize < size)
392 			break;
393 	ubz--;
394 	return (ubz->ubz_entries);
395 }
396 
397 static uma_bucket_t
398 bucket_alloc(uma_zone_t zone, void *udata, int flags)
399 {
400 	struct uma_bucket_zone *ubz;
401 	uma_bucket_t bucket;
402 
403 	/*
404 	 * This is to stop us from allocating per cpu buckets while we're
405 	 * running out of vm.boot_pages.  Otherwise, we would exhaust the
406 	 * boot pages.  This also prevents us from allocating buckets in
407 	 * low memory situations.
408 	 */
409 	if (bucketdisable)
410 		return (NULL);
411 	/*
412 	 * To limit bucket recursion we store the original zone flags
413 	 * in a cookie passed via zalloc_arg/zfree_arg.  This allows the
414 	 * NOVM flag to persist even through deep recursions.  We also
415 	 * store ZFLAG_BUCKET once we have recursed attempting to allocate
416 	 * a bucket for a bucket zone so we do not allow infinite bucket
417 	 * recursion.  This cookie will even persist to frees of unused
418 	 * buckets via the allocation path or bucket allocations in the
419 	 * free path.
420 	 */
421 	if ((zone->uz_flags & UMA_ZFLAG_BUCKET) == 0)
422 		udata = (void *)(uintptr_t)zone->uz_flags;
423 	else {
424 		if ((uintptr_t)udata & UMA_ZFLAG_BUCKET)
425 			return (NULL);
426 		udata = (void *)((uintptr_t)udata | UMA_ZFLAG_BUCKET);
427 	}
428 	if ((uintptr_t)udata & UMA_ZFLAG_CACHEONLY)
429 		flags |= M_NOVM;
430 	ubz = bucket_zone_lookup(zone->uz_count);
431 	if (ubz->ubz_zone == zone && (ubz + 1)->ubz_entries != 0)
432 		ubz++;
433 	bucket = uma_zalloc_arg(ubz->ubz_zone, udata, flags);
434 	if (bucket) {
435 #ifdef INVARIANTS
436 		bzero(bucket->ub_bucket, sizeof(void *) * ubz->ubz_entries);
437 #endif
438 		bucket->ub_cnt = 0;
439 		bucket->ub_entries = ubz->ubz_entries;
440 	}
441 
442 	return (bucket);
443 }
444 
445 static void
446 bucket_free(uma_zone_t zone, uma_bucket_t bucket, void *udata)
447 {
448 	struct uma_bucket_zone *ubz;
449 
450 	KASSERT(bucket->ub_cnt == 0,
451 	    ("bucket_free: Freeing a non free bucket."));
452 	if ((zone->uz_flags & UMA_ZFLAG_BUCKET) == 0)
453 		udata = (void *)(uintptr_t)zone->uz_flags;
454 	ubz = bucket_zone_lookup(bucket->ub_entries);
455 	uma_zfree_arg(ubz->ubz_zone, bucket, udata);
456 }
457 
458 static void
459 bucket_zone_drain(void)
460 {
461 	struct uma_bucket_zone *ubz;
462 
463 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
464 		zone_drain(ubz->ubz_zone);
465 }
466 
467 static uma_bucket_t
468 zone_try_fetch_bucket(uma_zone_t zone, uma_zone_domain_t zdom, const bool ws)
469 {
470 	uma_bucket_t bucket;
471 
472 	ZONE_LOCK_ASSERT(zone);
473 
474 	if ((bucket = LIST_FIRST(&zdom->uzd_buckets)) != NULL) {
475 		MPASS(zdom->uzd_nitems >= bucket->ub_cnt);
476 		LIST_REMOVE(bucket, ub_link);
477 		zdom->uzd_nitems -= bucket->ub_cnt;
478 		if (ws && zdom->uzd_imin > zdom->uzd_nitems)
479 			zdom->uzd_imin = zdom->uzd_nitems;
480 		zone->uz_bkt_count -= bucket->ub_cnt;
481 	}
482 	return (bucket);
483 }
484 
485 static void
486 zone_put_bucket(uma_zone_t zone, uma_zone_domain_t zdom, uma_bucket_t bucket,
487     const bool ws)
488 {
489 
490 	ZONE_LOCK_ASSERT(zone);
491 	KASSERT(zone->uz_bkt_count < zone->uz_bkt_max, ("%s: zone %p overflow",
492 	    __func__, zone));
493 
494 	LIST_INSERT_HEAD(&zdom->uzd_buckets, bucket, ub_link);
495 	zdom->uzd_nitems += bucket->ub_cnt;
496 	if (ws && zdom->uzd_imax < zdom->uzd_nitems)
497 		zdom->uzd_imax = zdom->uzd_nitems;
498 	zone->uz_bkt_count += bucket->ub_cnt;
499 }
500 
501 static void
502 zone_log_warning(uma_zone_t zone)
503 {
504 	static const struct timeval warninterval = { 300, 0 };
505 
506 	if (!zone_warnings || zone->uz_warning == NULL)
507 		return;
508 
509 	if (ratecheck(&zone->uz_ratecheck, &warninterval))
510 		printf("[zone: %s] %s\n", zone->uz_name, zone->uz_warning);
511 }
512 
513 static inline void
514 zone_maxaction(uma_zone_t zone)
515 {
516 
517 	if (zone->uz_maxaction.ta_func != NULL)
518 		taskqueue_enqueue(taskqueue_thread, &zone->uz_maxaction);
519 }
520 
521 /*
522  * Routine called by timeout which is used to fire off some time interval
523  * based calculations.  (stats, hash size, etc.)
524  *
525  * Arguments:
526  *	arg   Unused
527  *
528  * Returns:
529  *	Nothing
530  */
531 static void
532 uma_timeout(void *unused)
533 {
534 	bucket_enable();
535 	zone_foreach(zone_timeout);
536 
537 	/* Reschedule this event */
538 	callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
539 }
540 
541 /*
542  * Update the working set size estimate for the zone's bucket cache.
543  * The constants chosen here are somewhat arbitrary.  With an update period of
544  * 20s (UMA_TIMEOUT), this estimate is dominated by zone activity over the
545  * last 100s.
546  */
547 static void
548 zone_domain_update_wss(uma_zone_domain_t zdom)
549 {
550 	long wss;
551 
552 	MPASS(zdom->uzd_imax >= zdom->uzd_imin);
553 	wss = zdom->uzd_imax - zdom->uzd_imin;
554 	zdom->uzd_imax = zdom->uzd_imin = zdom->uzd_nitems;
555 	zdom->uzd_wss = (3 * wss + 2 * zdom->uzd_wss) / 5;
556 }
557 
558 /*
559  * Routine to perform timeout driven calculations.  This expands the
560  * hashes and does per cpu statistics aggregation.
561  *
562  *  Returns nothing.
563  */
564 static void
565 zone_timeout(uma_zone_t zone)
566 {
567 	uma_keg_t keg = zone->uz_keg;
568 
569 	KEG_LOCK(keg);
570 	/*
571 	 * Expand the keg hash table.
572 	 *
573 	 * This is done if the number of slabs is larger than the hash size.
574 	 * What I'm trying to do here is completely reduce collisions.  This
575 	 * may be a little aggressive.  Should I allow for two collisions max?
576 	 */
577 	if (keg->uk_flags & UMA_ZONE_HASH &&
578 	    keg->uk_pages / keg->uk_ppera >= keg->uk_hash.uh_hashsize) {
579 		struct uma_hash newhash;
580 		struct uma_hash oldhash;
581 		int ret;
582 
583 		/*
584 		 * This is so involved because allocating and freeing
585 		 * while the keg lock is held will lead to deadlock.
586 		 * I have to do everything in stages and check for
587 		 * races.
588 		 */
589 		newhash = keg->uk_hash;
590 		KEG_UNLOCK(keg);
591 		ret = hash_alloc(&newhash);
592 		KEG_LOCK(keg);
593 		if (ret) {
594 			if (hash_expand(&keg->uk_hash, &newhash)) {
595 				oldhash = keg->uk_hash;
596 				keg->uk_hash = newhash;
597 			} else
598 				oldhash = newhash;
599 
600 			KEG_UNLOCK(keg);
601 			hash_free(&oldhash);
602 			return;
603 		}
604 	}
605 
606 	for (int i = 0; i < vm_ndomains; i++)
607 		zone_domain_update_wss(&zone->uz_domain[i]);
608 
609 	KEG_UNLOCK(keg);
610 }
611 
612 /*
613  * Allocate and zero fill the next sized hash table from the appropriate
614  * backing store.
615  *
616  * Arguments:
617  *	hash  A new hash structure with the old hash size in uh_hashsize
618  *
619  * Returns:
620  *	1 on success and 0 on failure.
621  */
622 static int
623 hash_alloc(struct uma_hash *hash)
624 {
625 	int oldsize;
626 	int alloc;
627 
628 	oldsize = hash->uh_hashsize;
629 
630 	/* We're just going to go to a power of two greater */
631 	if (oldsize)  {
632 		hash->uh_hashsize = oldsize * 2;
633 		alloc = sizeof(hash->uh_slab_hash[0]) * hash->uh_hashsize;
634 		hash->uh_slab_hash = (struct slabhead *)malloc(alloc,
635 		    M_UMAHASH, M_NOWAIT);
636 	} else {
637 		alloc = sizeof(hash->uh_slab_hash[0]) * UMA_HASH_SIZE_INIT;
638 		hash->uh_slab_hash = zone_alloc_item(hashzone, NULL,
639 		    UMA_ANYDOMAIN, M_WAITOK);
640 		hash->uh_hashsize = UMA_HASH_SIZE_INIT;
641 	}
642 	if (hash->uh_slab_hash) {
643 		bzero(hash->uh_slab_hash, alloc);
644 		hash->uh_hashmask = hash->uh_hashsize - 1;
645 		return (1);
646 	}
647 
648 	return (0);
649 }
650 
651 /*
652  * Expands the hash table for HASH zones.  This is done from zone_timeout
653  * to reduce collisions.  This must not be done in the regular allocation
654  * path, otherwise, we can recurse on the vm while allocating pages.
655  *
656  * Arguments:
657  *	oldhash  The hash you want to expand
658  *	newhash  The hash structure for the new table
659  *
660  * Returns:
661  *	Nothing
662  *
663  * Discussion:
664  */
665 static int
666 hash_expand(struct uma_hash *oldhash, struct uma_hash *newhash)
667 {
668 	uma_slab_t slab;
669 	int hval;
670 	int i;
671 
672 	if (!newhash->uh_slab_hash)
673 		return (0);
674 
675 	if (oldhash->uh_hashsize >= newhash->uh_hashsize)
676 		return (0);
677 
678 	/*
679 	 * I need to investigate hash algorithms for resizing without a
680 	 * full rehash.
681 	 */
682 
683 	for (i = 0; i < oldhash->uh_hashsize; i++)
684 		while (!SLIST_EMPTY(&oldhash->uh_slab_hash[i])) {
685 			slab = SLIST_FIRST(&oldhash->uh_slab_hash[i]);
686 			SLIST_REMOVE_HEAD(&oldhash->uh_slab_hash[i], us_hlink);
687 			hval = UMA_HASH(newhash, slab->us_data);
688 			SLIST_INSERT_HEAD(&newhash->uh_slab_hash[hval],
689 			    slab, us_hlink);
690 		}
691 
692 	return (1);
693 }
694 
695 /*
696  * Free the hash bucket to the appropriate backing store.
697  *
698  * Arguments:
699  *	slab_hash  The hash bucket we're freeing
700  *	hashsize   The number of entries in that hash bucket
701  *
702  * Returns:
703  *	Nothing
704  */
705 static void
706 hash_free(struct uma_hash *hash)
707 {
708 	if (hash->uh_slab_hash == NULL)
709 		return;
710 	if (hash->uh_hashsize == UMA_HASH_SIZE_INIT)
711 		zone_free_item(hashzone, hash->uh_slab_hash, NULL, SKIP_NONE);
712 	else
713 		free(hash->uh_slab_hash, M_UMAHASH);
714 }
715 
716 /*
717  * Frees all outstanding items in a bucket
718  *
719  * Arguments:
720  *	zone   The zone to free to, must be unlocked.
721  *	bucket The free/alloc bucket with items, cpu queue must be locked.
722  *
723  * Returns:
724  *	Nothing
725  */
726 
727 static void
728 bucket_drain(uma_zone_t zone, uma_bucket_t bucket)
729 {
730 	int i;
731 
732 	if (bucket == NULL)
733 		return;
734 
735 	if (zone->uz_fini)
736 		for (i = 0; i < bucket->ub_cnt; i++)
737 			zone->uz_fini(bucket->ub_bucket[i], zone->uz_size);
738 	zone->uz_release(zone->uz_arg, bucket->ub_bucket, bucket->ub_cnt);
739 	if (zone->uz_max_items > 0) {
740 		ZONE_LOCK(zone);
741 		zone->uz_items -= bucket->ub_cnt;
742 		if (zone->uz_sleepers && zone->uz_items < zone->uz_max_items)
743 			wakeup_one(zone);
744 		ZONE_UNLOCK(zone);
745 	}
746 	bucket->ub_cnt = 0;
747 }
748 
749 /*
750  * Drains the per cpu caches for a zone.
751  *
752  * NOTE: This may only be called while the zone is being turn down, and not
753  * during normal operation.  This is necessary in order that we do not have
754  * to migrate CPUs to drain the per-CPU caches.
755  *
756  * Arguments:
757  *	zone     The zone to drain, must be unlocked.
758  *
759  * Returns:
760  *	Nothing
761  */
762 static void
763 cache_drain(uma_zone_t zone)
764 {
765 	uma_cache_t cache;
766 	int cpu;
767 
768 	/*
769 	 * XXX: It is safe to not lock the per-CPU caches, because we're
770 	 * tearing down the zone anyway.  I.e., there will be no further use
771 	 * of the caches at this point.
772 	 *
773 	 * XXX: It would good to be able to assert that the zone is being
774 	 * torn down to prevent improper use of cache_drain().
775 	 *
776 	 * XXX: We lock the zone before passing into bucket_cache_drain() as
777 	 * it is used elsewhere.  Should the tear-down path be made special
778 	 * there in some form?
779 	 */
780 	CPU_FOREACH(cpu) {
781 		cache = &zone->uz_cpu[cpu];
782 		bucket_drain(zone, cache->uc_allocbucket);
783 		bucket_drain(zone, cache->uc_freebucket);
784 		if (cache->uc_allocbucket != NULL)
785 			bucket_free(zone, cache->uc_allocbucket, NULL);
786 		if (cache->uc_freebucket != NULL)
787 			bucket_free(zone, cache->uc_freebucket, NULL);
788 		cache->uc_allocbucket = cache->uc_freebucket = NULL;
789 	}
790 	ZONE_LOCK(zone);
791 	bucket_cache_drain(zone);
792 	ZONE_UNLOCK(zone);
793 }
794 
795 static void
796 cache_shrink(uma_zone_t zone)
797 {
798 
799 	if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
800 		return;
801 
802 	ZONE_LOCK(zone);
803 	zone->uz_count = (zone->uz_count_min + zone->uz_count) / 2;
804 	ZONE_UNLOCK(zone);
805 }
806 
807 static void
808 cache_drain_safe_cpu(uma_zone_t zone)
809 {
810 	uma_cache_t cache;
811 	uma_bucket_t b1, b2;
812 	int domain;
813 
814 	if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
815 		return;
816 
817 	b1 = b2 = NULL;
818 	ZONE_LOCK(zone);
819 	critical_enter();
820 	if (zone->uz_flags & UMA_ZONE_NUMA)
821 		domain = PCPU_GET(domain);
822 	else
823 		domain = 0;
824 	cache = &zone->uz_cpu[curcpu];
825 	if (cache->uc_allocbucket) {
826 		if (cache->uc_allocbucket->ub_cnt != 0)
827 			zone_put_bucket(zone, &zone->uz_domain[domain],
828 			    cache->uc_allocbucket, false);
829 		else
830 			b1 = cache->uc_allocbucket;
831 		cache->uc_allocbucket = NULL;
832 	}
833 	if (cache->uc_freebucket) {
834 		if (cache->uc_freebucket->ub_cnt != 0)
835 			zone_put_bucket(zone, &zone->uz_domain[domain],
836 			    cache->uc_freebucket, false);
837 		else
838 			b2 = cache->uc_freebucket;
839 		cache->uc_freebucket = NULL;
840 	}
841 	critical_exit();
842 	ZONE_UNLOCK(zone);
843 	if (b1)
844 		bucket_free(zone, b1, NULL);
845 	if (b2)
846 		bucket_free(zone, b2, NULL);
847 }
848 
849 /*
850  * Safely drain per-CPU caches of a zone(s) to alloc bucket.
851  * This is an expensive call because it needs to bind to all CPUs
852  * one by one and enter a critical section on each of them in order
853  * to safely access their cache buckets.
854  * Zone lock must not be held on call this function.
855  */
856 static void
857 cache_drain_safe(uma_zone_t zone)
858 {
859 	int cpu;
860 
861 	/*
862 	 * Polite bucket sizes shrinking was not enouth, shrink aggressively.
863 	 */
864 	if (zone)
865 		cache_shrink(zone);
866 	else
867 		zone_foreach(cache_shrink);
868 
869 	CPU_FOREACH(cpu) {
870 		thread_lock(curthread);
871 		sched_bind(curthread, cpu);
872 		thread_unlock(curthread);
873 
874 		if (zone)
875 			cache_drain_safe_cpu(zone);
876 		else
877 			zone_foreach(cache_drain_safe_cpu);
878 	}
879 	thread_lock(curthread);
880 	sched_unbind(curthread);
881 	thread_unlock(curthread);
882 }
883 
884 /*
885  * Drain the cached buckets from a zone.  Expects a locked zone on entry.
886  */
887 static void
888 bucket_cache_drain(uma_zone_t zone)
889 {
890 	uma_zone_domain_t zdom;
891 	uma_bucket_t bucket;
892 	int i;
893 
894 	/*
895 	 * Drain the bucket queues and free the buckets.
896 	 */
897 	for (i = 0; i < vm_ndomains; i++) {
898 		zdom = &zone->uz_domain[i];
899 		while ((bucket = zone_try_fetch_bucket(zone, zdom, false)) !=
900 		    NULL) {
901 			ZONE_UNLOCK(zone);
902 			bucket_drain(zone, bucket);
903 			bucket_free(zone, bucket, NULL);
904 			ZONE_LOCK(zone);
905 		}
906 	}
907 
908 	/*
909 	 * Shrink further bucket sizes.  Price of single zone lock collision
910 	 * is probably lower then price of global cache drain.
911 	 */
912 	if (zone->uz_count > zone->uz_count_min)
913 		zone->uz_count--;
914 }
915 
916 static void
917 keg_free_slab(uma_keg_t keg, uma_slab_t slab, int start)
918 {
919 	uint8_t *mem;
920 	int i;
921 	uint8_t flags;
922 
923 	CTR4(KTR_UMA, "keg_free_slab keg %s(%p) slab %p, returning %d bytes",
924 	    keg->uk_name, keg, slab, PAGE_SIZE * keg->uk_ppera);
925 
926 	mem = slab->us_data;
927 	flags = slab->us_flags;
928 	i = start;
929 	if (keg->uk_fini != NULL) {
930 		for (i--; i > -1; i--)
931 #ifdef INVARIANTS
932 		/*
933 		 * trash_fini implies that dtor was trash_dtor. trash_fini
934 		 * would check that memory hasn't been modified since free,
935 		 * which executed trash_dtor.
936 		 * That's why we need to run uma_dbg_kskip() check here,
937 		 * albeit we don't make skip check for other init/fini
938 		 * invocations.
939 		 */
940 		if (!uma_dbg_kskip(keg, slab->us_data + (keg->uk_rsize * i)) ||
941 		    keg->uk_fini != trash_fini)
942 #endif
943 			keg->uk_fini(slab->us_data + (keg->uk_rsize * i),
944 			    keg->uk_size);
945 	}
946 	if (keg->uk_flags & UMA_ZONE_OFFPAGE)
947 		zone_free_item(keg->uk_slabzone, slab, NULL, SKIP_NONE);
948 	keg->uk_freef(mem, PAGE_SIZE * keg->uk_ppera, flags);
949 	uma_total_dec(PAGE_SIZE * keg->uk_ppera);
950 }
951 
952 /*
953  * Frees pages from a keg back to the system.  This is done on demand from
954  * the pageout daemon.
955  *
956  * Returns nothing.
957  */
958 static void
959 keg_drain(uma_keg_t keg)
960 {
961 	struct slabhead freeslabs = { 0 };
962 	uma_domain_t dom;
963 	uma_slab_t slab, tmp;
964 	int i;
965 
966 	/*
967 	 * We don't want to take pages from statically allocated kegs at this
968 	 * time
969 	 */
970 	if (keg->uk_flags & UMA_ZONE_NOFREE || keg->uk_freef == NULL)
971 		return;
972 
973 	CTR3(KTR_UMA, "keg_drain %s(%p) free items: %u",
974 	    keg->uk_name, keg, keg->uk_free);
975 	KEG_LOCK(keg);
976 	if (keg->uk_free == 0)
977 		goto finished;
978 
979 	for (i = 0; i < vm_ndomains; i++) {
980 		dom = &keg->uk_domain[i];
981 		LIST_FOREACH_SAFE(slab, &dom->ud_free_slab, us_link, tmp) {
982 			/* We have nowhere to free these to. */
983 			if (slab->us_flags & UMA_SLAB_BOOT)
984 				continue;
985 
986 			LIST_REMOVE(slab, us_link);
987 			keg->uk_pages -= keg->uk_ppera;
988 			keg->uk_free -= keg->uk_ipers;
989 
990 			if (keg->uk_flags & UMA_ZONE_HASH)
991 				UMA_HASH_REMOVE(&keg->uk_hash, slab,
992 				    slab->us_data);
993 
994 			SLIST_INSERT_HEAD(&freeslabs, slab, us_hlink);
995 		}
996 	}
997 
998 finished:
999 	KEG_UNLOCK(keg);
1000 
1001 	while ((slab = SLIST_FIRST(&freeslabs)) != NULL) {
1002 		SLIST_REMOVE(&freeslabs, slab, uma_slab, us_hlink);
1003 		keg_free_slab(keg, slab, keg->uk_ipers);
1004 	}
1005 }
1006 
1007 static void
1008 zone_drain_wait(uma_zone_t zone, int waitok)
1009 {
1010 
1011 	/*
1012 	 * Set draining to interlock with zone_dtor() so we can release our
1013 	 * locks as we go.  Only dtor() should do a WAITOK call since it
1014 	 * is the only call that knows the structure will still be available
1015 	 * when it wakes up.
1016 	 */
1017 	ZONE_LOCK(zone);
1018 	while (zone->uz_flags & UMA_ZFLAG_DRAINING) {
1019 		if (waitok == M_NOWAIT)
1020 			goto out;
1021 		msleep(zone, zone->uz_lockptr, PVM, "zonedrain", 1);
1022 	}
1023 	zone->uz_flags |= UMA_ZFLAG_DRAINING;
1024 	bucket_cache_drain(zone);
1025 	ZONE_UNLOCK(zone);
1026 	/*
1027 	 * The DRAINING flag protects us from being freed while
1028 	 * we're running.  Normally the uma_rwlock would protect us but we
1029 	 * must be able to release and acquire the right lock for each keg.
1030 	 */
1031 	keg_drain(zone->uz_keg);
1032 	ZONE_LOCK(zone);
1033 	zone->uz_flags &= ~UMA_ZFLAG_DRAINING;
1034 	wakeup(zone);
1035 out:
1036 	ZONE_UNLOCK(zone);
1037 }
1038 
1039 void
1040 zone_drain(uma_zone_t zone)
1041 {
1042 
1043 	zone_drain_wait(zone, M_NOWAIT);
1044 }
1045 
1046 /*
1047  * Allocate a new slab for a keg.  This does not insert the slab onto a list.
1048  * If the allocation was successful, the keg lock will be held upon return,
1049  * otherwise the keg will be left unlocked.
1050  *
1051  * Arguments:
1052  *	wait  Shall we wait?
1053  *
1054  * Returns:
1055  *	The slab that was allocated or NULL if there is no memory and the
1056  *	caller specified M_NOWAIT.
1057  */
1058 static uma_slab_t
1059 keg_alloc_slab(uma_keg_t keg, uma_zone_t zone, int domain, int wait)
1060 {
1061 	uma_alloc allocf;
1062 	uma_slab_t slab;
1063 	unsigned long size;
1064 	uint8_t *mem;
1065 	uint8_t flags;
1066 	int i;
1067 
1068 	KASSERT(domain >= 0 && domain < vm_ndomains,
1069 	    ("keg_alloc_slab: domain %d out of range", domain));
1070 	KEG_LOCK_ASSERT(keg);
1071 	MPASS(zone->uz_lockptr == &keg->uk_lock);
1072 
1073 	allocf = keg->uk_allocf;
1074 	KEG_UNLOCK(keg);
1075 
1076 	slab = NULL;
1077 	mem = NULL;
1078 	if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
1079 		slab = zone_alloc_item(keg->uk_slabzone, NULL, domain, wait);
1080 		if (slab == NULL)
1081 			goto out;
1082 	}
1083 
1084 	/*
1085 	 * This reproduces the old vm_zone behavior of zero filling pages the
1086 	 * first time they are added to a zone.
1087 	 *
1088 	 * Malloced items are zeroed in uma_zalloc.
1089 	 */
1090 
1091 	if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
1092 		wait |= M_ZERO;
1093 	else
1094 		wait &= ~M_ZERO;
1095 
1096 	if (keg->uk_flags & UMA_ZONE_NODUMP)
1097 		wait |= M_NODUMP;
1098 
1099 	/* zone is passed for legacy reasons. */
1100 	size = keg->uk_ppera * PAGE_SIZE;
1101 	mem = allocf(zone, size, domain, &flags, wait);
1102 	if (mem == NULL) {
1103 		if (keg->uk_flags & UMA_ZONE_OFFPAGE)
1104 			zone_free_item(keg->uk_slabzone, slab, NULL, SKIP_NONE);
1105 		slab = NULL;
1106 		goto out;
1107 	}
1108 	uma_total_inc(size);
1109 
1110 	/* Point the slab into the allocated memory */
1111 	if (!(keg->uk_flags & UMA_ZONE_OFFPAGE))
1112 		slab = (uma_slab_t )(mem + keg->uk_pgoff);
1113 
1114 	if (keg->uk_flags & UMA_ZONE_VTOSLAB)
1115 		for (i = 0; i < keg->uk_ppera; i++)
1116 			vsetslab((vm_offset_t)mem + (i * PAGE_SIZE), slab);
1117 
1118 	slab->us_keg = keg;
1119 	slab->us_data = mem;
1120 	slab->us_freecount = keg->uk_ipers;
1121 	slab->us_flags = flags;
1122 	slab->us_domain = domain;
1123 	BIT_FILL(SLAB_SETSIZE, &slab->us_free);
1124 #ifdef INVARIANTS
1125 	BIT_ZERO(SLAB_SETSIZE, &slab->us_debugfree);
1126 #endif
1127 
1128 	if (keg->uk_init != NULL) {
1129 		for (i = 0; i < keg->uk_ipers; i++)
1130 			if (keg->uk_init(slab->us_data + (keg->uk_rsize * i),
1131 			    keg->uk_size, wait) != 0)
1132 				break;
1133 		if (i != keg->uk_ipers) {
1134 			keg_free_slab(keg, slab, i);
1135 			slab = NULL;
1136 			goto out;
1137 		}
1138 	}
1139 	KEG_LOCK(keg);
1140 
1141 	CTR3(KTR_UMA, "keg_alloc_slab: allocated slab %p for %s(%p)",
1142 	    slab, keg->uk_name, keg);
1143 
1144 	if (keg->uk_flags & UMA_ZONE_HASH)
1145 		UMA_HASH_INSERT(&keg->uk_hash, slab, mem);
1146 
1147 	keg->uk_pages += keg->uk_ppera;
1148 	keg->uk_free += keg->uk_ipers;
1149 
1150 out:
1151 	return (slab);
1152 }
1153 
1154 /*
1155  * This function is intended to be used early on in place of page_alloc() so
1156  * that we may use the boot time page cache to satisfy allocations before
1157  * the VM is ready.
1158  */
1159 static void *
1160 startup_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
1161     int wait)
1162 {
1163 	uma_keg_t keg;
1164 	void *mem;
1165 	int pages;
1166 
1167 	keg = zone->uz_keg;
1168 	/*
1169 	 * If we are in BOOT_BUCKETS or higher, than switch to real
1170 	 * allocator.  Zones with page sized slabs switch at BOOT_PAGEALLOC.
1171 	 */
1172 	switch (booted) {
1173 		case BOOT_COLD:
1174 		case BOOT_STRAPPED:
1175 			break;
1176 		case BOOT_PAGEALLOC:
1177 			if (keg->uk_ppera > 1)
1178 				break;
1179 		case BOOT_BUCKETS:
1180 		case BOOT_RUNNING:
1181 #ifdef UMA_MD_SMALL_ALLOC
1182 			keg->uk_allocf = (keg->uk_ppera > 1) ?
1183 			    page_alloc : uma_small_alloc;
1184 #else
1185 			keg->uk_allocf = page_alloc;
1186 #endif
1187 			return keg->uk_allocf(zone, bytes, domain, pflag, wait);
1188 	}
1189 
1190 	/*
1191 	 * Check our small startup cache to see if it has pages remaining.
1192 	 */
1193 	pages = howmany(bytes, PAGE_SIZE);
1194 	KASSERT(pages > 0, ("%s can't reserve 0 pages", __func__));
1195 	if (pages > boot_pages)
1196 		panic("UMA zone \"%s\": Increase vm.boot_pages", zone->uz_name);
1197 #ifdef DIAGNOSTIC
1198 	printf("%s from \"%s\", %d boot pages left\n", __func__, zone->uz_name,
1199 	    boot_pages);
1200 #endif
1201 	mem = bootmem;
1202 	boot_pages -= pages;
1203 	bootmem += pages * PAGE_SIZE;
1204 	*pflag = UMA_SLAB_BOOT;
1205 
1206 	return (mem);
1207 }
1208 
1209 /*
1210  * Allocates a number of pages from the system
1211  *
1212  * Arguments:
1213  *	bytes  The number of bytes requested
1214  *	wait  Shall we wait?
1215  *
1216  * Returns:
1217  *	A pointer to the alloced memory or possibly
1218  *	NULL if M_NOWAIT is set.
1219  */
1220 static void *
1221 page_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
1222     int wait)
1223 {
1224 	void *p;	/* Returned page */
1225 
1226 	*pflag = UMA_SLAB_KERNEL;
1227 	p = (void *)kmem_malloc_domainset(DOMAINSET_FIXED(domain), bytes, wait);
1228 
1229 	return (p);
1230 }
1231 
1232 static void *
1233 pcpu_page_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
1234     int wait)
1235 {
1236 	struct pglist alloctail;
1237 	vm_offset_t addr, zkva;
1238 	int cpu, flags;
1239 	vm_page_t p, p_next;
1240 #ifdef NUMA
1241 	struct pcpu *pc;
1242 #endif
1243 
1244 	MPASS(bytes == (mp_maxid + 1) * PAGE_SIZE);
1245 
1246 	TAILQ_INIT(&alloctail);
1247 	flags = VM_ALLOC_SYSTEM | VM_ALLOC_WIRED | VM_ALLOC_NOOBJ |
1248 	    malloc2vm_flags(wait);
1249 	*pflag = UMA_SLAB_KERNEL;
1250 	for (cpu = 0; cpu <= mp_maxid; cpu++) {
1251 		if (CPU_ABSENT(cpu)) {
1252 			p = vm_page_alloc(NULL, 0, flags);
1253 		} else {
1254 #ifndef NUMA
1255 			p = vm_page_alloc(NULL, 0, flags);
1256 #else
1257 			pc = pcpu_find(cpu);
1258 			p = vm_page_alloc_domain(NULL, 0, pc->pc_domain, flags);
1259 			if (__predict_false(p == NULL))
1260 				p = vm_page_alloc(NULL, 0, flags);
1261 #endif
1262 		}
1263 		if (__predict_false(p == NULL))
1264 			goto fail;
1265 		TAILQ_INSERT_TAIL(&alloctail, p, listq);
1266 	}
1267 	if ((addr = kva_alloc(bytes)) == 0)
1268 		goto fail;
1269 	zkva = addr;
1270 	TAILQ_FOREACH(p, &alloctail, listq) {
1271 		pmap_qenter(zkva, &p, 1);
1272 		zkva += PAGE_SIZE;
1273 	}
1274 	return ((void*)addr);
1275  fail:
1276 	TAILQ_FOREACH_SAFE(p, &alloctail, listq, p_next) {
1277 		vm_page_unwire(p, PQ_NONE);
1278 		vm_page_free(p);
1279 	}
1280 	return (NULL);
1281 }
1282 
1283 /*
1284  * Allocates a number of pages from within an object
1285  *
1286  * Arguments:
1287  *	bytes  The number of bytes requested
1288  *	wait   Shall we wait?
1289  *
1290  * Returns:
1291  *	A pointer to the alloced memory or possibly
1292  *	NULL if M_NOWAIT is set.
1293  */
1294 static void *
1295 noobj_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *flags,
1296     int wait)
1297 {
1298 	TAILQ_HEAD(, vm_page) alloctail;
1299 	u_long npages;
1300 	vm_offset_t retkva, zkva;
1301 	vm_page_t p, p_next;
1302 	uma_keg_t keg;
1303 
1304 	TAILQ_INIT(&alloctail);
1305 	keg = zone->uz_keg;
1306 
1307 	npages = howmany(bytes, PAGE_SIZE);
1308 	while (npages > 0) {
1309 		p = vm_page_alloc_domain(NULL, 0, domain, VM_ALLOC_INTERRUPT |
1310 		    VM_ALLOC_WIRED | VM_ALLOC_NOOBJ |
1311 		    ((wait & M_WAITOK) != 0 ? VM_ALLOC_WAITOK :
1312 		    VM_ALLOC_NOWAIT));
1313 		if (p != NULL) {
1314 			/*
1315 			 * Since the page does not belong to an object, its
1316 			 * listq is unused.
1317 			 */
1318 			TAILQ_INSERT_TAIL(&alloctail, p, listq);
1319 			npages--;
1320 			continue;
1321 		}
1322 		/*
1323 		 * Page allocation failed, free intermediate pages and
1324 		 * exit.
1325 		 */
1326 		TAILQ_FOREACH_SAFE(p, &alloctail, listq, p_next) {
1327 			vm_page_unwire(p, PQ_NONE);
1328 			vm_page_free(p);
1329 		}
1330 		return (NULL);
1331 	}
1332 	*flags = UMA_SLAB_PRIV;
1333 	zkva = keg->uk_kva +
1334 	    atomic_fetchadd_long(&keg->uk_offset, round_page(bytes));
1335 	retkva = zkva;
1336 	TAILQ_FOREACH(p, &alloctail, listq) {
1337 		pmap_qenter(zkva, &p, 1);
1338 		zkva += PAGE_SIZE;
1339 	}
1340 
1341 	return ((void *)retkva);
1342 }
1343 
1344 /*
1345  * Frees a number of pages to the system
1346  *
1347  * Arguments:
1348  *	mem   A pointer to the memory to be freed
1349  *	size  The size of the memory being freed
1350  *	flags The original p->us_flags field
1351  *
1352  * Returns:
1353  *	Nothing
1354  */
1355 static void
1356 page_free(void *mem, vm_size_t size, uint8_t flags)
1357 {
1358 
1359 	if ((flags & UMA_SLAB_KERNEL) == 0)
1360 		panic("UMA: page_free used with invalid flags %x", flags);
1361 
1362 	kmem_free((vm_offset_t)mem, size);
1363 }
1364 
1365 /*
1366  * Frees pcpu zone allocations
1367  *
1368  * Arguments:
1369  *	mem   A pointer to the memory to be freed
1370  *	size  The size of the memory being freed
1371  *	flags The original p->us_flags field
1372  *
1373  * Returns:
1374  *	Nothing
1375  */
1376 static void
1377 pcpu_page_free(void *mem, vm_size_t size, uint8_t flags)
1378 {
1379 	vm_offset_t sva, curva;
1380 	vm_paddr_t paddr;
1381 	vm_page_t m;
1382 
1383 	MPASS(size == (mp_maxid+1)*PAGE_SIZE);
1384 	sva = (vm_offset_t)mem;
1385 	for (curva = sva; curva < sva + size; curva += PAGE_SIZE) {
1386 		paddr = pmap_kextract(curva);
1387 		m = PHYS_TO_VM_PAGE(paddr);
1388 		vm_page_unwire(m, PQ_NONE);
1389 		vm_page_free(m);
1390 	}
1391 	pmap_qremove(sva, size >> PAGE_SHIFT);
1392 	kva_free(sva, size);
1393 }
1394 
1395 
1396 /*
1397  * Zero fill initializer
1398  *
1399  * Arguments/Returns follow uma_init specifications
1400  */
1401 static int
1402 zero_init(void *mem, int size, int flags)
1403 {
1404 	bzero(mem, size);
1405 	return (0);
1406 }
1407 
1408 /*
1409  * Finish creating a small uma keg.  This calculates ipers, and the keg size.
1410  *
1411  * Arguments
1412  *	keg  The zone we should initialize
1413  *
1414  * Returns
1415  *	Nothing
1416  */
1417 static void
1418 keg_small_init(uma_keg_t keg)
1419 {
1420 	u_int rsize;
1421 	u_int memused;
1422 	u_int wastedspace;
1423 	u_int shsize;
1424 	u_int slabsize;
1425 
1426 	if (keg->uk_flags & UMA_ZONE_PCPU) {
1427 		u_int ncpus = (mp_maxid + 1) ? (mp_maxid + 1) : MAXCPU;
1428 
1429 		slabsize = UMA_PCPU_ALLOC_SIZE;
1430 		keg->uk_ppera = ncpus;
1431 	} else {
1432 		slabsize = UMA_SLAB_SIZE;
1433 		keg->uk_ppera = 1;
1434 	}
1435 
1436 	/*
1437 	 * Calculate the size of each allocation (rsize) according to
1438 	 * alignment.  If the requested size is smaller than we have
1439 	 * allocation bits for we round it up.
1440 	 */
1441 	rsize = keg->uk_size;
1442 	if (rsize < slabsize / SLAB_SETSIZE)
1443 		rsize = slabsize / SLAB_SETSIZE;
1444 	if (rsize & keg->uk_align)
1445 		rsize = (rsize & ~keg->uk_align) + (keg->uk_align + 1);
1446 	keg->uk_rsize = rsize;
1447 
1448 	KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0 ||
1449 	    keg->uk_rsize < UMA_PCPU_ALLOC_SIZE,
1450 	    ("%s: size %u too large", __func__, keg->uk_rsize));
1451 
1452 	if (keg->uk_flags & UMA_ZONE_OFFPAGE)
1453 		shsize = 0;
1454 	else
1455 		shsize = SIZEOF_UMA_SLAB;
1456 
1457 	if (rsize <= slabsize - shsize)
1458 		keg->uk_ipers = (slabsize - shsize) / rsize;
1459 	else {
1460 		/* Handle special case when we have 1 item per slab, so
1461 		 * alignment requirement can be relaxed. */
1462 		KASSERT(keg->uk_size <= slabsize - shsize,
1463 		    ("%s: size %u greater than slab", __func__, keg->uk_size));
1464 		keg->uk_ipers = 1;
1465 	}
1466 	KASSERT(keg->uk_ipers > 0 && keg->uk_ipers <= SLAB_SETSIZE,
1467 	    ("%s: keg->uk_ipers %u", __func__, keg->uk_ipers));
1468 
1469 	memused = keg->uk_ipers * rsize + shsize;
1470 	wastedspace = slabsize - memused;
1471 
1472 	/*
1473 	 * We can't do OFFPAGE if we're internal or if we've been
1474 	 * asked to not go to the VM for buckets.  If we do this we
1475 	 * may end up going to the VM  for slabs which we do not
1476 	 * want to do if we're UMA_ZFLAG_CACHEONLY as a result
1477 	 * of UMA_ZONE_VM, which clearly forbids it.
1478 	 */
1479 	if ((keg->uk_flags & UMA_ZFLAG_INTERNAL) ||
1480 	    (keg->uk_flags & UMA_ZFLAG_CACHEONLY))
1481 		return;
1482 
1483 	/*
1484 	 * See if using an OFFPAGE slab will limit our waste.  Only do
1485 	 * this if it permits more items per-slab.
1486 	 *
1487 	 * XXX We could try growing slabsize to limit max waste as well.
1488 	 * Historically this was not done because the VM could not
1489 	 * efficiently handle contiguous allocations.
1490 	 */
1491 	if ((wastedspace >= slabsize / UMA_MAX_WASTE) &&
1492 	    (keg->uk_ipers < (slabsize / keg->uk_rsize))) {
1493 		keg->uk_ipers = slabsize / keg->uk_rsize;
1494 		KASSERT(keg->uk_ipers > 0 && keg->uk_ipers <= SLAB_SETSIZE,
1495 		    ("%s: keg->uk_ipers %u", __func__, keg->uk_ipers));
1496 		CTR6(KTR_UMA, "UMA decided we need offpage slab headers for "
1497 		    "keg: %s(%p), calculated wastedspace = %d, "
1498 		    "maximum wasted space allowed = %d, "
1499 		    "calculated ipers = %d, "
1500 		    "new wasted space = %d\n", keg->uk_name, keg, wastedspace,
1501 		    slabsize / UMA_MAX_WASTE, keg->uk_ipers,
1502 		    slabsize - keg->uk_ipers * keg->uk_rsize);
1503 		keg->uk_flags |= UMA_ZONE_OFFPAGE;
1504 	}
1505 
1506 	if ((keg->uk_flags & UMA_ZONE_OFFPAGE) &&
1507 	    (keg->uk_flags & UMA_ZONE_VTOSLAB) == 0)
1508 		keg->uk_flags |= UMA_ZONE_HASH;
1509 }
1510 
1511 /*
1512  * Finish creating a large (> UMA_SLAB_SIZE) uma kegs.  Just give in and do
1513  * OFFPAGE for now.  When I can allow for more dynamic slab sizes this will be
1514  * more complicated.
1515  *
1516  * Arguments
1517  *	keg  The keg we should initialize
1518  *
1519  * Returns
1520  *	Nothing
1521  */
1522 static void
1523 keg_large_init(uma_keg_t keg)
1524 {
1525 
1526 	KASSERT(keg != NULL, ("Keg is null in keg_large_init"));
1527 	KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0,
1528 	    ("%s: Cannot large-init a UMA_ZONE_PCPU keg", __func__));
1529 
1530 	keg->uk_ppera = howmany(keg->uk_size, PAGE_SIZE);
1531 	keg->uk_ipers = 1;
1532 	keg->uk_rsize = keg->uk_size;
1533 
1534 	/* Check whether we have enough space to not do OFFPAGE. */
1535 	if ((keg->uk_flags & UMA_ZONE_OFFPAGE) == 0 &&
1536 	    PAGE_SIZE * keg->uk_ppera - keg->uk_rsize < SIZEOF_UMA_SLAB) {
1537 		/*
1538 		 * We can't do OFFPAGE if we're internal, in which case
1539 		 * we need an extra page per allocation to contain the
1540 		 * slab header.
1541 		 */
1542 		if ((keg->uk_flags & UMA_ZFLAG_INTERNAL) == 0)
1543 			keg->uk_flags |= UMA_ZONE_OFFPAGE;
1544 		else
1545 			keg->uk_ppera++;
1546 	}
1547 
1548 	if ((keg->uk_flags & UMA_ZONE_OFFPAGE) &&
1549 	    (keg->uk_flags & UMA_ZONE_VTOSLAB) == 0)
1550 		keg->uk_flags |= UMA_ZONE_HASH;
1551 }
1552 
1553 static void
1554 keg_cachespread_init(uma_keg_t keg)
1555 {
1556 	int alignsize;
1557 	int trailer;
1558 	int pages;
1559 	int rsize;
1560 
1561 	KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0,
1562 	    ("%s: Cannot cachespread-init a UMA_ZONE_PCPU keg", __func__));
1563 
1564 	alignsize = keg->uk_align + 1;
1565 	rsize = keg->uk_size;
1566 	/*
1567 	 * We want one item to start on every align boundary in a page.  To
1568 	 * do this we will span pages.  We will also extend the item by the
1569 	 * size of align if it is an even multiple of align.  Otherwise, it
1570 	 * would fall on the same boundary every time.
1571 	 */
1572 	if (rsize & keg->uk_align)
1573 		rsize = (rsize & ~keg->uk_align) + alignsize;
1574 	if ((rsize & alignsize) == 0)
1575 		rsize += alignsize;
1576 	trailer = rsize - keg->uk_size;
1577 	pages = (rsize * (PAGE_SIZE / alignsize)) / PAGE_SIZE;
1578 	pages = MIN(pages, (128 * 1024) / PAGE_SIZE);
1579 	keg->uk_rsize = rsize;
1580 	keg->uk_ppera = pages;
1581 	keg->uk_ipers = ((pages * PAGE_SIZE) + trailer) / rsize;
1582 	keg->uk_flags |= UMA_ZONE_OFFPAGE | UMA_ZONE_VTOSLAB;
1583 	KASSERT(keg->uk_ipers <= SLAB_SETSIZE,
1584 	    ("%s: keg->uk_ipers too high(%d) increase max_ipers", __func__,
1585 	    keg->uk_ipers));
1586 }
1587 
1588 /*
1589  * Keg header ctor.  This initializes all fields, locks, etc.  And inserts
1590  * the keg onto the global keg list.
1591  *
1592  * Arguments/Returns follow uma_ctor specifications
1593  *	udata  Actually uma_kctor_args
1594  */
1595 static int
1596 keg_ctor(void *mem, int size, void *udata, int flags)
1597 {
1598 	struct uma_kctor_args *arg = udata;
1599 	uma_keg_t keg = mem;
1600 	uma_zone_t zone;
1601 
1602 	bzero(keg, size);
1603 	keg->uk_size = arg->size;
1604 	keg->uk_init = arg->uminit;
1605 	keg->uk_fini = arg->fini;
1606 	keg->uk_align = arg->align;
1607 	keg->uk_free = 0;
1608 	keg->uk_reserve = 0;
1609 	keg->uk_pages = 0;
1610 	keg->uk_flags = arg->flags;
1611 	keg->uk_slabzone = NULL;
1612 
1613 	/*
1614 	 * We use a global round-robin policy by default.  Zones with
1615 	 * UMA_ZONE_NUMA set will use first-touch instead, in which case the
1616 	 * iterator is never run.
1617 	 */
1618 	keg->uk_dr.dr_policy = DOMAINSET_RR();
1619 	keg->uk_dr.dr_iter = 0;
1620 
1621 	/*
1622 	 * The master zone is passed to us at keg-creation time.
1623 	 */
1624 	zone = arg->zone;
1625 	keg->uk_name = zone->uz_name;
1626 
1627 	if (arg->flags & UMA_ZONE_VM)
1628 		keg->uk_flags |= UMA_ZFLAG_CACHEONLY;
1629 
1630 	if (arg->flags & UMA_ZONE_ZINIT)
1631 		keg->uk_init = zero_init;
1632 
1633 	if (arg->flags & UMA_ZONE_MALLOC)
1634 		keg->uk_flags |= UMA_ZONE_VTOSLAB;
1635 
1636 	if (arg->flags & UMA_ZONE_PCPU)
1637 #ifdef SMP
1638 		keg->uk_flags |= UMA_ZONE_OFFPAGE;
1639 #else
1640 		keg->uk_flags &= ~UMA_ZONE_PCPU;
1641 #endif
1642 
1643 	if (keg->uk_flags & UMA_ZONE_CACHESPREAD) {
1644 		keg_cachespread_init(keg);
1645 	} else {
1646 		if (keg->uk_size > UMA_SLAB_SPACE)
1647 			keg_large_init(keg);
1648 		else
1649 			keg_small_init(keg);
1650 	}
1651 
1652 	if (keg->uk_flags & UMA_ZONE_OFFPAGE)
1653 		keg->uk_slabzone = slabzone;
1654 
1655 	/*
1656 	 * If we haven't booted yet we need allocations to go through the
1657 	 * startup cache until the vm is ready.
1658 	 */
1659 	if (booted < BOOT_PAGEALLOC)
1660 		keg->uk_allocf = startup_alloc;
1661 #ifdef UMA_MD_SMALL_ALLOC
1662 	else if (keg->uk_ppera == 1)
1663 		keg->uk_allocf = uma_small_alloc;
1664 #endif
1665 	else if (keg->uk_flags & UMA_ZONE_PCPU)
1666 		keg->uk_allocf = pcpu_page_alloc;
1667 	else
1668 		keg->uk_allocf = page_alloc;
1669 #ifdef UMA_MD_SMALL_ALLOC
1670 	if (keg->uk_ppera == 1)
1671 		keg->uk_freef = uma_small_free;
1672 	else
1673 #endif
1674 	if (keg->uk_flags & UMA_ZONE_PCPU)
1675 		keg->uk_freef = pcpu_page_free;
1676 	else
1677 		keg->uk_freef = page_free;
1678 
1679 	/*
1680 	 * Initialize keg's lock
1681 	 */
1682 	KEG_LOCK_INIT(keg, (arg->flags & UMA_ZONE_MTXCLASS));
1683 
1684 	/*
1685 	 * If we're putting the slab header in the actual page we need to
1686 	 * figure out where in each page it goes.  See SIZEOF_UMA_SLAB
1687 	 * macro definition.
1688 	 */
1689 	if (!(keg->uk_flags & UMA_ZONE_OFFPAGE)) {
1690 		keg->uk_pgoff = (PAGE_SIZE * keg->uk_ppera) - SIZEOF_UMA_SLAB;
1691 		/*
1692 		 * The only way the following is possible is if with our
1693 		 * UMA_ALIGN_PTR adjustments we are now bigger than
1694 		 * UMA_SLAB_SIZE.  I haven't checked whether this is
1695 		 * mathematically possible for all cases, so we make
1696 		 * sure here anyway.
1697 		 */
1698 		KASSERT(keg->uk_pgoff + sizeof(struct uma_slab) <=
1699 		    PAGE_SIZE * keg->uk_ppera,
1700 		    ("zone %s ipers %d rsize %d size %d slab won't fit",
1701 		    zone->uz_name, keg->uk_ipers, keg->uk_rsize, keg->uk_size));
1702 	}
1703 
1704 	if (keg->uk_flags & UMA_ZONE_HASH)
1705 		hash_alloc(&keg->uk_hash);
1706 
1707 	CTR5(KTR_UMA, "keg_ctor %p zone %s(%p) out %d free %d\n",
1708 	    keg, zone->uz_name, zone,
1709 	    (keg->uk_pages / keg->uk_ppera) * keg->uk_ipers - keg->uk_free,
1710 	    keg->uk_free);
1711 
1712 	LIST_INSERT_HEAD(&keg->uk_zones, zone, uz_link);
1713 
1714 	rw_wlock(&uma_rwlock);
1715 	LIST_INSERT_HEAD(&uma_kegs, keg, uk_link);
1716 	rw_wunlock(&uma_rwlock);
1717 	return (0);
1718 }
1719 
1720 static void
1721 zone_alloc_counters(uma_zone_t zone)
1722 {
1723 
1724 	zone->uz_allocs = counter_u64_alloc(M_WAITOK);
1725 	zone->uz_frees = counter_u64_alloc(M_WAITOK);
1726 	zone->uz_fails = counter_u64_alloc(M_WAITOK);
1727 }
1728 
1729 /*
1730  * Zone header ctor.  This initializes all fields, locks, etc.
1731  *
1732  * Arguments/Returns follow uma_ctor specifications
1733  *	udata  Actually uma_zctor_args
1734  */
1735 static int
1736 zone_ctor(void *mem, int size, void *udata, int flags)
1737 {
1738 	struct uma_zctor_args *arg = udata;
1739 	uma_zone_t zone = mem;
1740 	uma_zone_t z;
1741 	uma_keg_t keg;
1742 
1743 	bzero(zone, size);
1744 	zone->uz_name = arg->name;
1745 	zone->uz_ctor = arg->ctor;
1746 	zone->uz_dtor = arg->dtor;
1747 	zone->uz_slab = zone_fetch_slab;
1748 	zone->uz_init = NULL;
1749 	zone->uz_fini = NULL;
1750 	zone->uz_sleeps = 0;
1751 	zone->uz_count = 0;
1752 	zone->uz_count_min = 0;
1753 	zone->uz_count_max = BUCKET_MAX;
1754 	zone->uz_flags = 0;
1755 	zone->uz_warning = NULL;
1756 	/* The domain structures follow the cpu structures. */
1757 	zone->uz_domain = (struct uma_zone_domain *)&zone->uz_cpu[mp_ncpus];
1758 	zone->uz_bkt_max = ULONG_MAX;
1759 	timevalclear(&zone->uz_ratecheck);
1760 
1761 	if (__predict_true(booted == BOOT_RUNNING))
1762 		zone_alloc_counters(zone);
1763 	else {
1764 		zone->uz_allocs = EARLY_COUNTER;
1765 		zone->uz_frees = EARLY_COUNTER;
1766 		zone->uz_fails = EARLY_COUNTER;
1767 	}
1768 
1769 	/*
1770 	 * This is a pure cache zone, no kegs.
1771 	 */
1772 	if (arg->import) {
1773 		if (arg->flags & UMA_ZONE_VM)
1774 			arg->flags |= UMA_ZFLAG_CACHEONLY;
1775 		zone->uz_flags = arg->flags;
1776 		zone->uz_size = arg->size;
1777 		zone->uz_import = arg->import;
1778 		zone->uz_release = arg->release;
1779 		zone->uz_arg = arg->arg;
1780 		zone->uz_lockptr = &zone->uz_lock;
1781 		ZONE_LOCK_INIT(zone, (arg->flags & UMA_ZONE_MTXCLASS));
1782 		rw_wlock(&uma_rwlock);
1783 		LIST_INSERT_HEAD(&uma_cachezones, zone, uz_link);
1784 		rw_wunlock(&uma_rwlock);
1785 		goto out;
1786 	}
1787 
1788 	/*
1789 	 * Use the regular zone/keg/slab allocator.
1790 	 */
1791 	zone->uz_import = (uma_import)zone_import;
1792 	zone->uz_release = (uma_release)zone_release;
1793 	zone->uz_arg = zone;
1794 	keg = arg->keg;
1795 
1796 	if (arg->flags & UMA_ZONE_SECONDARY) {
1797 		KASSERT(arg->keg != NULL, ("Secondary zone on zero'd keg"));
1798 		zone->uz_init = arg->uminit;
1799 		zone->uz_fini = arg->fini;
1800 		zone->uz_lockptr = &keg->uk_lock;
1801 		zone->uz_flags |= UMA_ZONE_SECONDARY;
1802 		rw_wlock(&uma_rwlock);
1803 		ZONE_LOCK(zone);
1804 		LIST_FOREACH(z, &keg->uk_zones, uz_link) {
1805 			if (LIST_NEXT(z, uz_link) == NULL) {
1806 				LIST_INSERT_AFTER(z, zone, uz_link);
1807 				break;
1808 			}
1809 		}
1810 		ZONE_UNLOCK(zone);
1811 		rw_wunlock(&uma_rwlock);
1812 	} else if (keg == NULL) {
1813 		if ((keg = uma_kcreate(zone, arg->size, arg->uminit, arg->fini,
1814 		    arg->align, arg->flags)) == NULL)
1815 			return (ENOMEM);
1816 	} else {
1817 		struct uma_kctor_args karg;
1818 		int error;
1819 
1820 		/* We should only be here from uma_startup() */
1821 		karg.size = arg->size;
1822 		karg.uminit = arg->uminit;
1823 		karg.fini = arg->fini;
1824 		karg.align = arg->align;
1825 		karg.flags = arg->flags;
1826 		karg.zone = zone;
1827 		error = keg_ctor(arg->keg, sizeof(struct uma_keg), &karg,
1828 		    flags);
1829 		if (error)
1830 			return (error);
1831 	}
1832 
1833 	zone->uz_keg = keg;
1834 	zone->uz_size = keg->uk_size;
1835 	zone->uz_flags |= (keg->uk_flags &
1836 	    (UMA_ZONE_INHERIT | UMA_ZFLAG_INHERIT));
1837 
1838 	/*
1839 	 * Some internal zones don't have room allocated for the per cpu
1840 	 * caches.  If we're internal, bail out here.
1841 	 */
1842 	if (keg->uk_flags & UMA_ZFLAG_INTERNAL) {
1843 		KASSERT((zone->uz_flags & UMA_ZONE_SECONDARY) == 0,
1844 		    ("Secondary zone requested UMA_ZFLAG_INTERNAL"));
1845 		return (0);
1846 	}
1847 
1848 out:
1849 	KASSERT((arg->flags & (UMA_ZONE_MAXBUCKET | UMA_ZONE_NOBUCKET)) !=
1850 	    (UMA_ZONE_MAXBUCKET | UMA_ZONE_NOBUCKET),
1851 	    ("Invalid zone flag combination"));
1852 	if ((arg->flags & UMA_ZONE_MAXBUCKET) != 0)
1853 		zone->uz_count = BUCKET_MAX;
1854 	else if ((arg->flags & UMA_ZONE_NOBUCKET) != 0)
1855 		zone->uz_count = 0;
1856 	else
1857 		zone->uz_count = bucket_select(zone->uz_size);
1858 	zone->uz_count_min = zone->uz_count;
1859 
1860 	return (0);
1861 }
1862 
1863 /*
1864  * Keg header dtor.  This frees all data, destroys locks, frees the hash
1865  * table and removes the keg from the global list.
1866  *
1867  * Arguments/Returns follow uma_dtor specifications
1868  *	udata  unused
1869  */
1870 static void
1871 keg_dtor(void *arg, int size, void *udata)
1872 {
1873 	uma_keg_t keg;
1874 
1875 	keg = (uma_keg_t)arg;
1876 	KEG_LOCK(keg);
1877 	if (keg->uk_free != 0) {
1878 		printf("Freed UMA keg (%s) was not empty (%d items). "
1879 		    " Lost %d pages of memory.\n",
1880 		    keg->uk_name ? keg->uk_name : "",
1881 		    keg->uk_free, keg->uk_pages);
1882 	}
1883 	KEG_UNLOCK(keg);
1884 
1885 	hash_free(&keg->uk_hash);
1886 
1887 	KEG_LOCK_FINI(keg);
1888 }
1889 
1890 /*
1891  * Zone header dtor.
1892  *
1893  * Arguments/Returns follow uma_dtor specifications
1894  *	udata  unused
1895  */
1896 static void
1897 zone_dtor(void *arg, int size, void *udata)
1898 {
1899 	uma_zone_t zone;
1900 	uma_keg_t keg;
1901 
1902 	zone = (uma_zone_t)arg;
1903 
1904 	if (!(zone->uz_flags & UMA_ZFLAG_INTERNAL))
1905 		cache_drain(zone);
1906 
1907 	rw_wlock(&uma_rwlock);
1908 	LIST_REMOVE(zone, uz_link);
1909 	rw_wunlock(&uma_rwlock);
1910 	/*
1911 	 * XXX there are some races here where
1912 	 * the zone can be drained but zone lock
1913 	 * released and then refilled before we
1914 	 * remove it... we dont care for now
1915 	 */
1916 	zone_drain_wait(zone, M_WAITOK);
1917 	/*
1918 	 * We only destroy kegs from non secondary zones.
1919 	 */
1920 	if ((keg = zone->uz_keg) != NULL &&
1921 	    (zone->uz_flags & UMA_ZONE_SECONDARY) == 0)  {
1922 		rw_wlock(&uma_rwlock);
1923 		LIST_REMOVE(keg, uk_link);
1924 		rw_wunlock(&uma_rwlock);
1925 		zone_free_item(kegs, keg, NULL, SKIP_NONE);
1926 	}
1927 	counter_u64_free(zone->uz_allocs);
1928 	counter_u64_free(zone->uz_frees);
1929 	counter_u64_free(zone->uz_fails);
1930 	if (zone->uz_lockptr == &zone->uz_lock)
1931 		ZONE_LOCK_FINI(zone);
1932 }
1933 
1934 /*
1935  * Traverses every zone in the system and calls a callback
1936  *
1937  * Arguments:
1938  *	zfunc  A pointer to a function which accepts a zone
1939  *		as an argument.
1940  *
1941  * Returns:
1942  *	Nothing
1943  */
1944 static void
1945 zone_foreach(void (*zfunc)(uma_zone_t))
1946 {
1947 	uma_keg_t keg;
1948 	uma_zone_t zone;
1949 
1950 	/*
1951 	 * Before BOOT_RUNNING we are guaranteed to be single
1952 	 * threaded, so locking isn't needed. Startup functions
1953 	 * are allowed to use M_WAITOK.
1954 	 */
1955 	if (__predict_true(booted == BOOT_RUNNING))
1956 		rw_rlock(&uma_rwlock);
1957 	LIST_FOREACH(keg, &uma_kegs, uk_link) {
1958 		LIST_FOREACH(zone, &keg->uk_zones, uz_link)
1959 			zfunc(zone);
1960 	}
1961 	if (__predict_true(booted == BOOT_RUNNING))
1962 		rw_runlock(&uma_rwlock);
1963 }
1964 
1965 /*
1966  * Count how many pages do we need to bootstrap.  VM supplies
1967  * its need in early zones in the argument, we add up our zones,
1968  * which consist of: UMA Slabs, UMA Hash and 9 Bucket zones. The
1969  * zone of zones and zone of kegs are accounted separately.
1970  */
1971 #define	UMA_BOOT_ZONES	11
1972 /* Zone of zones and zone of kegs have arbitrary alignment. */
1973 #define	UMA_BOOT_ALIGN	32
1974 static int zsize, ksize;
1975 int
1976 uma_startup_count(int vm_zones)
1977 {
1978 	int zones, pages;
1979 
1980 	ksize = sizeof(struct uma_keg) +
1981 	    (sizeof(struct uma_domain) * vm_ndomains);
1982 	zsize = sizeof(struct uma_zone) +
1983 	    (sizeof(struct uma_cache) * (mp_maxid + 1)) +
1984 	    (sizeof(struct uma_zone_domain) * vm_ndomains);
1985 
1986 	/*
1987 	 * Memory for the zone of kegs and its keg,
1988 	 * and for zone of zones.
1989 	 */
1990 	pages = howmany(roundup(zsize, CACHE_LINE_SIZE) * 2 +
1991 	    roundup(ksize, CACHE_LINE_SIZE), PAGE_SIZE);
1992 
1993 #ifdef	UMA_MD_SMALL_ALLOC
1994 	zones = UMA_BOOT_ZONES;
1995 #else
1996 	zones = UMA_BOOT_ZONES + vm_zones;
1997 	vm_zones = 0;
1998 #endif
1999 
2000 	/* Memory for the rest of startup zones, UMA and VM, ... */
2001 	if (zsize > UMA_SLAB_SPACE) {
2002 		/* See keg_large_init(). */
2003 		u_int ppera;
2004 
2005 		ppera = howmany(roundup2(zsize, UMA_BOOT_ALIGN), PAGE_SIZE);
2006 		if (PAGE_SIZE * ppera - roundup2(zsize, UMA_BOOT_ALIGN) <
2007 		    SIZEOF_UMA_SLAB)
2008 			ppera++;
2009 		pages += (zones + vm_zones) * ppera;
2010 	} else if (roundup2(zsize, UMA_BOOT_ALIGN) > UMA_SLAB_SPACE)
2011 		/* See keg_small_init() special case for uk_ppera = 1. */
2012 		pages += zones;
2013 	else
2014 		pages += howmany(zones,
2015 		    UMA_SLAB_SPACE / roundup2(zsize, UMA_BOOT_ALIGN));
2016 
2017 	/* ... and their kegs. Note that zone of zones allocates a keg! */
2018 	pages += howmany(zones + 1,
2019 	    UMA_SLAB_SPACE / roundup2(ksize, UMA_BOOT_ALIGN));
2020 
2021 	/*
2022 	 * Most of startup zones are not going to be offpages, that's
2023 	 * why we use UMA_SLAB_SPACE instead of UMA_SLAB_SIZE in all
2024 	 * calculations.  Some large bucket zones will be offpage, and
2025 	 * thus will allocate hashes.  We take conservative approach
2026 	 * and assume that all zones may allocate hash.  This may give
2027 	 * us some positive inaccuracy, usually an extra single page.
2028 	 */
2029 	pages += howmany(zones, UMA_SLAB_SPACE /
2030 	    (sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT));
2031 
2032 	return (pages);
2033 }
2034 
2035 void
2036 uma_startup(void *mem, int npages)
2037 {
2038 	struct uma_zctor_args args;
2039 	uma_keg_t masterkeg;
2040 	uintptr_t m;
2041 
2042 #ifdef DIAGNOSTIC
2043 	printf("Entering %s with %d boot pages configured\n", __func__, npages);
2044 #endif
2045 
2046 	rw_init(&uma_rwlock, "UMA lock");
2047 
2048 	/* Use bootpages memory for the zone of zones and zone of kegs. */
2049 	m = (uintptr_t)mem;
2050 	zones = (uma_zone_t)m;
2051 	m += roundup(zsize, CACHE_LINE_SIZE);
2052 	kegs = (uma_zone_t)m;
2053 	m += roundup(zsize, CACHE_LINE_SIZE);
2054 	masterkeg = (uma_keg_t)m;
2055 	m += roundup(ksize, CACHE_LINE_SIZE);
2056 	m = roundup(m, PAGE_SIZE);
2057 	npages -= (m - (uintptr_t)mem) / PAGE_SIZE;
2058 	mem = (void *)m;
2059 
2060 	/* "manually" create the initial zone */
2061 	memset(&args, 0, sizeof(args));
2062 	args.name = "UMA Kegs";
2063 	args.size = ksize;
2064 	args.ctor = keg_ctor;
2065 	args.dtor = keg_dtor;
2066 	args.uminit = zero_init;
2067 	args.fini = NULL;
2068 	args.keg = masterkeg;
2069 	args.align = UMA_BOOT_ALIGN - 1;
2070 	args.flags = UMA_ZFLAG_INTERNAL;
2071 	zone_ctor(kegs, zsize, &args, M_WAITOK);
2072 
2073 	bootmem = mem;
2074 	boot_pages = npages;
2075 
2076 	args.name = "UMA Zones";
2077 	args.size = zsize;
2078 	args.ctor = zone_ctor;
2079 	args.dtor = zone_dtor;
2080 	args.uminit = zero_init;
2081 	args.fini = NULL;
2082 	args.keg = NULL;
2083 	args.align = UMA_BOOT_ALIGN - 1;
2084 	args.flags = UMA_ZFLAG_INTERNAL;
2085 	zone_ctor(zones, zsize, &args, M_WAITOK);
2086 
2087 	/* Now make a zone for slab headers */
2088 	slabzone = uma_zcreate("UMA Slabs",
2089 				sizeof(struct uma_slab),
2090 				NULL, NULL, NULL, NULL,
2091 				UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
2092 
2093 	hashzone = uma_zcreate("UMA Hash",
2094 	    sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT,
2095 	    NULL, NULL, NULL, NULL,
2096 	    UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
2097 
2098 	bucket_init();
2099 
2100 	booted = BOOT_STRAPPED;
2101 }
2102 
2103 void
2104 uma_startup1(void)
2105 {
2106 
2107 #ifdef DIAGNOSTIC
2108 	printf("Entering %s with %d boot pages left\n", __func__, boot_pages);
2109 #endif
2110 	booted = BOOT_PAGEALLOC;
2111 }
2112 
2113 void
2114 uma_startup2(void)
2115 {
2116 
2117 #ifdef DIAGNOSTIC
2118 	printf("Entering %s with %d boot pages left\n", __func__, boot_pages);
2119 #endif
2120 	booted = BOOT_BUCKETS;
2121 	sx_init(&uma_drain_lock, "umadrain");
2122 	bucket_enable();
2123 }
2124 
2125 /*
2126  * Initialize our callout handle
2127  *
2128  */
2129 static void
2130 uma_startup3(void)
2131 {
2132 
2133 #ifdef INVARIANTS
2134 	TUNABLE_INT_FETCH("vm.debug.divisor", &dbg_divisor);
2135 	uma_dbg_cnt = counter_u64_alloc(M_WAITOK);
2136 	uma_skip_cnt = counter_u64_alloc(M_WAITOK);
2137 #endif
2138 	zone_foreach(zone_alloc_counters);
2139 	callout_init(&uma_callout, 1);
2140 	callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
2141 	booted = BOOT_RUNNING;
2142 }
2143 
2144 static uma_keg_t
2145 uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini,
2146 		int align, uint32_t flags)
2147 {
2148 	struct uma_kctor_args args;
2149 
2150 	args.size = size;
2151 	args.uminit = uminit;
2152 	args.fini = fini;
2153 	args.align = (align == UMA_ALIGN_CACHE) ? uma_align_cache : align;
2154 	args.flags = flags;
2155 	args.zone = zone;
2156 	return (zone_alloc_item(kegs, &args, UMA_ANYDOMAIN, M_WAITOK));
2157 }
2158 
2159 /* Public functions */
2160 /* See uma.h */
2161 void
2162 uma_set_align(int align)
2163 {
2164 
2165 	if (align != UMA_ALIGN_CACHE)
2166 		uma_align_cache = align;
2167 }
2168 
2169 /* See uma.h */
2170 uma_zone_t
2171 uma_zcreate(const char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
2172 		uma_init uminit, uma_fini fini, int align, uint32_t flags)
2173 
2174 {
2175 	struct uma_zctor_args args;
2176 	uma_zone_t res;
2177 	bool locked;
2178 
2179 	KASSERT(powerof2(align + 1), ("invalid zone alignment %d for \"%s\"",
2180 	    align, name));
2181 
2182 	/* This stuff is essential for the zone ctor */
2183 	memset(&args, 0, sizeof(args));
2184 	args.name = name;
2185 	args.size = size;
2186 	args.ctor = ctor;
2187 	args.dtor = dtor;
2188 	args.uminit = uminit;
2189 	args.fini = fini;
2190 #ifdef  INVARIANTS
2191 	/*
2192 	 * If a zone is being created with an empty constructor and
2193 	 * destructor, pass UMA constructor/destructor which checks for
2194 	 * memory use after free.
2195 	 */
2196 	if ((!(flags & (UMA_ZONE_ZINIT | UMA_ZONE_NOFREE))) &&
2197 	    ctor == NULL && dtor == NULL && uminit == NULL && fini == NULL) {
2198 		args.ctor = trash_ctor;
2199 		args.dtor = trash_dtor;
2200 		args.uminit = trash_init;
2201 		args.fini = trash_fini;
2202 	}
2203 #endif
2204 	args.align = align;
2205 	args.flags = flags;
2206 	args.keg = NULL;
2207 
2208 	if (booted < BOOT_BUCKETS) {
2209 		locked = false;
2210 	} else {
2211 		sx_slock(&uma_drain_lock);
2212 		locked = true;
2213 	}
2214 	res = zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK);
2215 	if (locked)
2216 		sx_sunlock(&uma_drain_lock);
2217 	return (res);
2218 }
2219 
2220 /* See uma.h */
2221 uma_zone_t
2222 uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
2223 		    uma_init zinit, uma_fini zfini, uma_zone_t master)
2224 {
2225 	struct uma_zctor_args args;
2226 	uma_keg_t keg;
2227 	uma_zone_t res;
2228 	bool locked;
2229 
2230 	keg = master->uz_keg;
2231 	memset(&args, 0, sizeof(args));
2232 	args.name = name;
2233 	args.size = keg->uk_size;
2234 	args.ctor = ctor;
2235 	args.dtor = dtor;
2236 	args.uminit = zinit;
2237 	args.fini = zfini;
2238 	args.align = keg->uk_align;
2239 	args.flags = keg->uk_flags | UMA_ZONE_SECONDARY;
2240 	args.keg = keg;
2241 
2242 	if (booted < BOOT_BUCKETS) {
2243 		locked = false;
2244 	} else {
2245 		sx_slock(&uma_drain_lock);
2246 		locked = true;
2247 	}
2248 	/* XXX Attaches only one keg of potentially many. */
2249 	res = zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK);
2250 	if (locked)
2251 		sx_sunlock(&uma_drain_lock);
2252 	return (res);
2253 }
2254 
2255 /* See uma.h */
2256 uma_zone_t
2257 uma_zcache_create(char *name, int size, uma_ctor ctor, uma_dtor dtor,
2258 		    uma_init zinit, uma_fini zfini, uma_import zimport,
2259 		    uma_release zrelease, void *arg, int flags)
2260 {
2261 	struct uma_zctor_args args;
2262 
2263 	memset(&args, 0, sizeof(args));
2264 	args.name = name;
2265 	args.size = size;
2266 	args.ctor = ctor;
2267 	args.dtor = dtor;
2268 	args.uminit = zinit;
2269 	args.fini = zfini;
2270 	args.import = zimport;
2271 	args.release = zrelease;
2272 	args.arg = arg;
2273 	args.align = 0;
2274 	args.flags = flags | UMA_ZFLAG_CACHE;
2275 
2276 	return (zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK));
2277 }
2278 
2279 /* See uma.h */
2280 void
2281 uma_zdestroy(uma_zone_t zone)
2282 {
2283 
2284 	sx_slock(&uma_drain_lock);
2285 	zone_free_item(zones, zone, NULL, SKIP_NONE);
2286 	sx_sunlock(&uma_drain_lock);
2287 }
2288 
2289 void
2290 uma_zwait(uma_zone_t zone)
2291 {
2292 	void *item;
2293 
2294 	item = uma_zalloc_arg(zone, NULL, M_WAITOK);
2295 	uma_zfree(zone, item);
2296 }
2297 
2298 void *
2299 uma_zalloc_pcpu_arg(uma_zone_t zone, void *udata, int flags)
2300 {
2301 	void *item;
2302 #ifdef SMP
2303 	int i;
2304 
2305 	MPASS(zone->uz_flags & UMA_ZONE_PCPU);
2306 #endif
2307 	item = uma_zalloc_arg(zone, udata, flags & ~M_ZERO);
2308 	if (item != NULL && (flags & M_ZERO)) {
2309 #ifdef SMP
2310 		for (i = 0; i <= mp_maxid; i++)
2311 			bzero(zpcpu_get_cpu(item, i), zone->uz_size);
2312 #else
2313 		bzero(item, zone->uz_size);
2314 #endif
2315 	}
2316 	return (item);
2317 }
2318 
2319 /*
2320  * A stub while both regular and pcpu cases are identical.
2321  */
2322 void
2323 uma_zfree_pcpu_arg(uma_zone_t zone, void *item, void *udata)
2324 {
2325 
2326 #ifdef SMP
2327 	MPASS(zone->uz_flags & UMA_ZONE_PCPU);
2328 #endif
2329 	uma_zfree_arg(zone, item, udata);
2330 }
2331 
2332 /* See uma.h */
2333 void *
2334 uma_zalloc_arg(uma_zone_t zone, void *udata, int flags)
2335 {
2336 	uma_zone_domain_t zdom;
2337 	uma_bucket_t bucket;
2338 	uma_cache_t cache;
2339 	void *item;
2340 	int cpu, domain, lockfail, maxbucket;
2341 #ifdef INVARIANTS
2342 	bool skipdbg;
2343 #endif
2344 
2345 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
2346 	random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
2347 
2348 	/* This is the fast path allocation */
2349 	CTR4(KTR_UMA, "uma_zalloc_arg thread %x zone %s(%p) flags %d",
2350 	    curthread, zone->uz_name, zone, flags);
2351 
2352 	if (flags & M_WAITOK) {
2353 		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
2354 		    "uma_zalloc_arg: zone \"%s\"", zone->uz_name);
2355 	}
2356 	KASSERT((flags & M_EXEC) == 0, ("uma_zalloc_arg: called with M_EXEC"));
2357 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
2358 	    ("uma_zalloc_arg: called with spinlock or critical section held"));
2359 	if (zone->uz_flags & UMA_ZONE_PCPU)
2360 		KASSERT((flags & M_ZERO) == 0, ("allocating from a pcpu zone "
2361 		    "with M_ZERO passed"));
2362 
2363 #ifdef DEBUG_MEMGUARD
2364 	if (memguard_cmp_zone(zone)) {
2365 		item = memguard_alloc(zone->uz_size, flags);
2366 		if (item != NULL) {
2367 			if (zone->uz_init != NULL &&
2368 			    zone->uz_init(item, zone->uz_size, flags) != 0)
2369 				return (NULL);
2370 			if (zone->uz_ctor != NULL &&
2371 			    zone->uz_ctor(item, zone->uz_size, udata,
2372 			    flags) != 0) {
2373 			    	zone->uz_fini(item, zone->uz_size);
2374 				return (NULL);
2375 			}
2376 			return (item);
2377 		}
2378 		/* This is unfortunate but should not be fatal. */
2379 	}
2380 #endif
2381 	/*
2382 	 * If possible, allocate from the per-CPU cache.  There are two
2383 	 * requirements for safe access to the per-CPU cache: (1) the thread
2384 	 * accessing the cache must not be preempted or yield during access,
2385 	 * and (2) the thread must not migrate CPUs without switching which
2386 	 * cache it accesses.  We rely on a critical section to prevent
2387 	 * preemption and migration.  We release the critical section in
2388 	 * order to acquire the zone mutex if we are unable to allocate from
2389 	 * the current cache; when we re-acquire the critical section, we
2390 	 * must detect and handle migration if it has occurred.
2391 	 */
2392 zalloc_restart:
2393 	critical_enter();
2394 	cpu = curcpu;
2395 	cache = &zone->uz_cpu[cpu];
2396 
2397 zalloc_start:
2398 	bucket = cache->uc_allocbucket;
2399 	if (bucket != NULL && bucket->ub_cnt > 0) {
2400 		bucket->ub_cnt--;
2401 		item = bucket->ub_bucket[bucket->ub_cnt];
2402 #ifdef INVARIANTS
2403 		bucket->ub_bucket[bucket->ub_cnt] = NULL;
2404 #endif
2405 		KASSERT(item != NULL, ("uma_zalloc: Bucket pointer mangled."));
2406 		cache->uc_allocs++;
2407 		critical_exit();
2408 #ifdef INVARIANTS
2409 		skipdbg = uma_dbg_zskip(zone, item);
2410 #endif
2411 		if (zone->uz_ctor != NULL &&
2412 #ifdef INVARIANTS
2413 		    (!skipdbg || zone->uz_ctor != trash_ctor ||
2414 		    zone->uz_dtor != trash_dtor) &&
2415 #endif
2416 		    zone->uz_ctor(item, zone->uz_size, udata, flags) != 0) {
2417 			counter_u64_add(zone->uz_fails, 1);
2418 			zone_free_item(zone, item, udata, SKIP_DTOR | SKIP_CNT);
2419 			return (NULL);
2420 		}
2421 #ifdef INVARIANTS
2422 		if (!skipdbg)
2423 			uma_dbg_alloc(zone, NULL, item);
2424 #endif
2425 		if (flags & M_ZERO)
2426 			uma_zero_item(item, zone);
2427 		return (item);
2428 	}
2429 
2430 	/*
2431 	 * We have run out of items in our alloc bucket.
2432 	 * See if we can switch with our free bucket.
2433 	 */
2434 	bucket = cache->uc_freebucket;
2435 	if (bucket != NULL && bucket->ub_cnt > 0) {
2436 		CTR2(KTR_UMA,
2437 		    "uma_zalloc: zone %s(%p) swapping empty with alloc",
2438 		    zone->uz_name, zone);
2439 		cache->uc_freebucket = cache->uc_allocbucket;
2440 		cache->uc_allocbucket = bucket;
2441 		goto zalloc_start;
2442 	}
2443 
2444 	/*
2445 	 * Discard any empty allocation bucket while we hold no locks.
2446 	 */
2447 	bucket = cache->uc_allocbucket;
2448 	cache->uc_allocbucket = NULL;
2449 	critical_exit();
2450 	if (bucket != NULL)
2451 		bucket_free(zone, bucket, udata);
2452 
2453 	if (zone->uz_flags & UMA_ZONE_NUMA) {
2454 		domain = PCPU_GET(domain);
2455 		if (VM_DOMAIN_EMPTY(domain))
2456 			domain = UMA_ANYDOMAIN;
2457 	} else
2458 		domain = UMA_ANYDOMAIN;
2459 
2460 	/* Short-circuit for zones without buckets and low memory. */
2461 	if (zone->uz_count == 0 || bucketdisable) {
2462 		ZONE_LOCK(zone);
2463 		goto zalloc_item;
2464 	}
2465 
2466 	/*
2467 	 * Attempt to retrieve the item from the per-CPU cache has failed, so
2468 	 * we must go back to the zone.  This requires the zone lock, so we
2469 	 * must drop the critical section, then re-acquire it when we go back
2470 	 * to the cache.  Since the critical section is released, we may be
2471 	 * preempted or migrate.  As such, make sure not to maintain any
2472 	 * thread-local state specific to the cache from prior to releasing
2473 	 * the critical section.
2474 	 */
2475 	lockfail = 0;
2476 	if (ZONE_TRYLOCK(zone) == 0) {
2477 		/* Record contention to size the buckets. */
2478 		ZONE_LOCK(zone);
2479 		lockfail = 1;
2480 	}
2481 	critical_enter();
2482 	cpu = curcpu;
2483 	cache = &zone->uz_cpu[cpu];
2484 
2485 	/* See if we lost the race to fill the cache. */
2486 	if (cache->uc_allocbucket != NULL) {
2487 		ZONE_UNLOCK(zone);
2488 		goto zalloc_start;
2489 	}
2490 
2491 	/*
2492 	 * Check the zone's cache of buckets.
2493 	 */
2494 	if (domain == UMA_ANYDOMAIN)
2495 		zdom = &zone->uz_domain[0];
2496 	else
2497 		zdom = &zone->uz_domain[domain];
2498 	if ((bucket = zone_try_fetch_bucket(zone, zdom, true)) != NULL) {
2499 		KASSERT(bucket->ub_cnt != 0,
2500 		    ("uma_zalloc_arg: Returning an empty bucket."));
2501 		cache->uc_allocbucket = bucket;
2502 		ZONE_UNLOCK(zone);
2503 		goto zalloc_start;
2504 	}
2505 	/* We are no longer associated with this CPU. */
2506 	critical_exit();
2507 
2508 	/*
2509 	 * We bump the uz count when the cache size is insufficient to
2510 	 * handle the working set.
2511 	 */
2512 	if (lockfail && zone->uz_count < zone->uz_count_max)
2513 		zone->uz_count++;
2514 
2515 	if (zone->uz_max_items > 0) {
2516 		if (zone->uz_items >= zone->uz_max_items)
2517 			goto zalloc_item;
2518 		maxbucket = MIN(zone->uz_count,
2519 		    zone->uz_max_items - zone->uz_items);
2520 		zone->uz_items += maxbucket;
2521 	} else
2522 		maxbucket = zone->uz_count;
2523 	ZONE_UNLOCK(zone);
2524 
2525 	/*
2526 	 * Now lets just fill a bucket and put it on the free list.  If that
2527 	 * works we'll restart the allocation from the beginning and it
2528 	 * will use the just filled bucket.
2529 	 */
2530 	bucket = zone_alloc_bucket(zone, udata, domain, flags, maxbucket);
2531 	CTR3(KTR_UMA, "uma_zalloc: zone %s(%p) bucket zone returned %p",
2532 	    zone->uz_name, zone, bucket);
2533 	ZONE_LOCK(zone);
2534 	if (bucket != NULL) {
2535 		if (zone->uz_max_items > 0 && bucket->ub_cnt < maxbucket) {
2536 			MPASS(zone->uz_items >= maxbucket - bucket->ub_cnt);
2537 			zone->uz_items -= maxbucket - bucket->ub_cnt;
2538 			if (zone->uz_sleepers > 0 &&
2539 			    zone->uz_items < zone->uz_max_items)
2540 				wakeup_one(zone);
2541 		}
2542 		critical_enter();
2543 		cpu = curcpu;
2544 		cache = &zone->uz_cpu[cpu];
2545 
2546 		/*
2547 		 * See if we lost the race or were migrated.  Cache the
2548 		 * initialized bucket to make this less likely or claim
2549 		 * the memory directly.
2550 		 */
2551 		if (cache->uc_allocbucket == NULL &&
2552 		    ((zone->uz_flags & UMA_ZONE_NUMA) == 0 ||
2553 		    domain == PCPU_GET(domain))) {
2554 			cache->uc_allocbucket = bucket;
2555 			zdom->uzd_imax += bucket->ub_cnt;
2556 		} else if (zone->uz_bkt_count >= zone->uz_bkt_max) {
2557 			critical_exit();
2558 			ZONE_UNLOCK(zone);
2559 			bucket_drain(zone, bucket);
2560 			bucket_free(zone, bucket, udata);
2561 			goto zalloc_restart;
2562 		} else
2563 			zone_put_bucket(zone, zdom, bucket, false);
2564 		ZONE_UNLOCK(zone);
2565 		goto zalloc_start;
2566 	} else if (zone->uz_max_items > 0) {
2567 		zone->uz_items -= maxbucket;
2568 		if (zone->uz_sleepers > 0 &&
2569 		    zone->uz_items + 1 < zone->uz_max_items)
2570 			wakeup_one(zone);
2571 	}
2572 
2573 	/*
2574 	 * We may not be able to get a bucket so return an actual item.
2575 	 */
2576 zalloc_item:
2577 	item = zone_alloc_item_locked(zone, udata, domain, flags);
2578 
2579 	return (item);
2580 }
2581 
2582 void *
2583 uma_zalloc_domain(uma_zone_t zone, void *udata, int domain, int flags)
2584 {
2585 
2586 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
2587 	random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
2588 
2589 	/* This is the fast path allocation */
2590 	CTR5(KTR_UMA,
2591 	    "uma_zalloc_domain thread %x zone %s(%p) domain %d flags %d",
2592 	    curthread, zone->uz_name, zone, domain, flags);
2593 
2594 	if (flags & M_WAITOK) {
2595 		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
2596 		    "uma_zalloc_domain: zone \"%s\"", zone->uz_name);
2597 	}
2598 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
2599 	    ("uma_zalloc_domain: called with spinlock or critical section held"));
2600 
2601 	return (zone_alloc_item(zone, udata, domain, flags));
2602 }
2603 
2604 /*
2605  * Find a slab with some space.  Prefer slabs that are partially used over those
2606  * that are totally full.  This helps to reduce fragmentation.
2607  *
2608  * If 'rr' is 1, search all domains starting from 'domain'.  Otherwise check
2609  * only 'domain'.
2610  */
2611 static uma_slab_t
2612 keg_first_slab(uma_keg_t keg, int domain, bool rr)
2613 {
2614 	uma_domain_t dom;
2615 	uma_slab_t slab;
2616 	int start;
2617 
2618 	KASSERT(domain >= 0 && domain < vm_ndomains,
2619 	    ("keg_first_slab: domain %d out of range", domain));
2620 	KEG_LOCK_ASSERT(keg);
2621 
2622 	slab = NULL;
2623 	start = domain;
2624 	do {
2625 		dom = &keg->uk_domain[domain];
2626 		if (!LIST_EMPTY(&dom->ud_part_slab))
2627 			return (LIST_FIRST(&dom->ud_part_slab));
2628 		if (!LIST_EMPTY(&dom->ud_free_slab)) {
2629 			slab = LIST_FIRST(&dom->ud_free_slab);
2630 			LIST_REMOVE(slab, us_link);
2631 			LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
2632 			return (slab);
2633 		}
2634 		if (rr)
2635 			domain = (domain + 1) % vm_ndomains;
2636 	} while (domain != start);
2637 
2638 	return (NULL);
2639 }
2640 
2641 static uma_slab_t
2642 keg_fetch_free_slab(uma_keg_t keg, int domain, bool rr, int flags)
2643 {
2644 	uint32_t reserve;
2645 
2646 	KEG_LOCK_ASSERT(keg);
2647 
2648 	reserve = (flags & M_USE_RESERVE) != 0 ? 0 : keg->uk_reserve;
2649 	if (keg->uk_free <= reserve)
2650 		return (NULL);
2651 	return (keg_first_slab(keg, domain, rr));
2652 }
2653 
2654 static uma_slab_t
2655 keg_fetch_slab(uma_keg_t keg, uma_zone_t zone, int rdomain, const int flags)
2656 {
2657 	struct vm_domainset_iter di;
2658 	uma_domain_t dom;
2659 	uma_slab_t slab;
2660 	int aflags, domain;
2661 	bool rr;
2662 
2663 restart:
2664 	KEG_LOCK_ASSERT(keg);
2665 
2666 	/*
2667 	 * Use the keg's policy if upper layers haven't already specified a
2668 	 * domain (as happens with first-touch zones).
2669 	 *
2670 	 * To avoid races we run the iterator with the keg lock held, but that
2671 	 * means that we cannot allow the vm_domainset layer to sleep.  Thus,
2672 	 * clear M_WAITOK and handle low memory conditions locally.
2673 	 */
2674 	rr = rdomain == UMA_ANYDOMAIN;
2675 	if (rr) {
2676 		aflags = (flags & ~M_WAITOK) | M_NOWAIT;
2677 		vm_domainset_iter_policy_ref_init(&di, &keg->uk_dr, &domain,
2678 		    &aflags);
2679 	} else {
2680 		aflags = flags;
2681 		domain = rdomain;
2682 	}
2683 
2684 	for (;;) {
2685 		slab = keg_fetch_free_slab(keg, domain, rr, flags);
2686 		if (slab != NULL) {
2687 			MPASS(slab->us_keg == keg);
2688 			return (slab);
2689 		}
2690 
2691 		/*
2692 		 * M_NOVM means don't ask at all!
2693 		 */
2694 		if (flags & M_NOVM)
2695 			break;
2696 
2697 		KASSERT(zone->uz_max_items == 0 ||
2698 		    zone->uz_items <= zone->uz_max_items,
2699 		    ("%s: zone %p overflow", __func__, zone));
2700 
2701 		slab = keg_alloc_slab(keg, zone, domain, aflags);
2702 		/*
2703 		 * If we got a slab here it's safe to mark it partially used
2704 		 * and return.  We assume that the caller is going to remove
2705 		 * at least one item.
2706 		 */
2707 		if (slab) {
2708 			MPASS(slab->us_keg == keg);
2709 			dom = &keg->uk_domain[slab->us_domain];
2710 			LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
2711 			return (slab);
2712 		}
2713 		KEG_LOCK(keg);
2714 		if (rr && vm_domainset_iter_policy(&di, &domain) != 0) {
2715 			if ((flags & M_WAITOK) != 0) {
2716 				KEG_UNLOCK(keg);
2717 				vm_wait_doms(&keg->uk_dr.dr_policy->ds_mask);
2718 				KEG_LOCK(keg);
2719 				goto restart;
2720 			}
2721 			break;
2722 		}
2723 	}
2724 
2725 	/*
2726 	 * We might not have been able to get a slab but another cpu
2727 	 * could have while we were unlocked.  Check again before we
2728 	 * fail.
2729 	 */
2730 	if ((slab = keg_fetch_free_slab(keg, domain, rr, flags)) != NULL) {
2731 		MPASS(slab->us_keg == keg);
2732 		return (slab);
2733 	}
2734 	return (NULL);
2735 }
2736 
2737 static uma_slab_t
2738 zone_fetch_slab(uma_zone_t zone, uma_keg_t keg, int domain, int flags)
2739 {
2740 	uma_slab_t slab;
2741 
2742 	if (keg == NULL) {
2743 		keg = zone->uz_keg;
2744 		KEG_LOCK(keg);
2745 	}
2746 
2747 	for (;;) {
2748 		slab = keg_fetch_slab(keg, zone, domain, flags);
2749 		if (slab)
2750 			return (slab);
2751 		if (flags & (M_NOWAIT | M_NOVM))
2752 			break;
2753 	}
2754 	KEG_UNLOCK(keg);
2755 	return (NULL);
2756 }
2757 
2758 static void *
2759 slab_alloc_item(uma_keg_t keg, uma_slab_t slab)
2760 {
2761 	uma_domain_t dom;
2762 	void *item;
2763 	uint8_t freei;
2764 
2765 	MPASS(keg == slab->us_keg);
2766 	KEG_LOCK_ASSERT(keg);
2767 
2768 	freei = BIT_FFS(SLAB_SETSIZE, &slab->us_free) - 1;
2769 	BIT_CLR(SLAB_SETSIZE, freei, &slab->us_free);
2770 	item = slab->us_data + (keg->uk_rsize * freei);
2771 	slab->us_freecount--;
2772 	keg->uk_free--;
2773 
2774 	/* Move this slab to the full list */
2775 	if (slab->us_freecount == 0) {
2776 		LIST_REMOVE(slab, us_link);
2777 		dom = &keg->uk_domain[slab->us_domain];
2778 		LIST_INSERT_HEAD(&dom->ud_full_slab, slab, us_link);
2779 	}
2780 
2781 	return (item);
2782 }
2783 
2784 static int
2785 zone_import(uma_zone_t zone, void **bucket, int max, int domain, int flags)
2786 {
2787 	uma_slab_t slab;
2788 	uma_keg_t keg;
2789 #ifdef NUMA
2790 	int stripe;
2791 #endif
2792 	int i;
2793 
2794 	slab = NULL;
2795 	keg = NULL;
2796 	/* Try to keep the buckets totally full */
2797 	for (i = 0; i < max; ) {
2798 		if ((slab = zone->uz_slab(zone, keg, domain, flags)) == NULL)
2799 			break;
2800 		keg = slab->us_keg;
2801 #ifdef NUMA
2802 		stripe = howmany(max, vm_ndomains);
2803 #endif
2804 		while (slab->us_freecount && i < max) {
2805 			bucket[i++] = slab_alloc_item(keg, slab);
2806 			if (keg->uk_free <= keg->uk_reserve)
2807 				break;
2808 #ifdef NUMA
2809 			/*
2810 			 * If the zone is striped we pick a new slab for every
2811 			 * N allocations.  Eliminating this conditional will
2812 			 * instead pick a new domain for each bucket rather
2813 			 * than stripe within each bucket.  The current option
2814 			 * produces more fragmentation and requires more cpu
2815 			 * time but yields better distribution.
2816 			 */
2817 			if ((zone->uz_flags & UMA_ZONE_NUMA) == 0 &&
2818 			    vm_ndomains > 1 && --stripe == 0)
2819 				break;
2820 #endif
2821 		}
2822 		/* Don't block if we allocated any successfully. */
2823 		flags &= ~M_WAITOK;
2824 		flags |= M_NOWAIT;
2825 	}
2826 	if (slab != NULL)
2827 		KEG_UNLOCK(keg);
2828 
2829 	return i;
2830 }
2831 
2832 static uma_bucket_t
2833 zone_alloc_bucket(uma_zone_t zone, void *udata, int domain, int flags, int max)
2834 {
2835 	uma_bucket_t bucket;
2836 
2837 	CTR1(KTR_UMA, "zone_alloc:_bucket domain %d)", domain);
2838 
2839 	/* Don't wait for buckets, preserve caller's NOVM setting. */
2840 	bucket = bucket_alloc(zone, udata, M_NOWAIT | (flags & M_NOVM));
2841 	if (bucket == NULL)
2842 		return (NULL);
2843 
2844 	bucket->ub_cnt = zone->uz_import(zone->uz_arg, bucket->ub_bucket,
2845 	    max, domain, flags);
2846 
2847 	/*
2848 	 * Initialize the memory if necessary.
2849 	 */
2850 	if (bucket->ub_cnt != 0 && zone->uz_init != NULL) {
2851 		int i;
2852 
2853 		for (i = 0; i < bucket->ub_cnt; i++)
2854 			if (zone->uz_init(bucket->ub_bucket[i], zone->uz_size,
2855 			    flags) != 0)
2856 				break;
2857 		/*
2858 		 * If we couldn't initialize the whole bucket, put the
2859 		 * rest back onto the freelist.
2860 		 */
2861 		if (i != bucket->ub_cnt) {
2862 			zone->uz_release(zone->uz_arg, &bucket->ub_bucket[i],
2863 			    bucket->ub_cnt - i);
2864 #ifdef INVARIANTS
2865 			bzero(&bucket->ub_bucket[i],
2866 			    sizeof(void *) * (bucket->ub_cnt - i));
2867 #endif
2868 			bucket->ub_cnt = i;
2869 		}
2870 	}
2871 
2872 	if (bucket->ub_cnt == 0) {
2873 		bucket_free(zone, bucket, udata);
2874 		counter_u64_add(zone->uz_fails, 1);
2875 		return (NULL);
2876 	}
2877 
2878 	return (bucket);
2879 }
2880 
2881 /*
2882  * Allocates a single item from a zone.
2883  *
2884  * Arguments
2885  *	zone   The zone to alloc for.
2886  *	udata  The data to be passed to the constructor.
2887  *	domain The domain to allocate from or UMA_ANYDOMAIN.
2888  *	flags  M_WAITOK, M_NOWAIT, M_ZERO.
2889  *
2890  * Returns
2891  *	NULL if there is no memory and M_NOWAIT is set
2892  *	An item if successful
2893  */
2894 
2895 static void *
2896 zone_alloc_item(uma_zone_t zone, void *udata, int domain, int flags)
2897 {
2898 
2899 	ZONE_LOCK(zone);
2900 	return (zone_alloc_item_locked(zone, udata, domain, flags));
2901 }
2902 
2903 /*
2904  * Returns with zone unlocked.
2905  */
2906 static void *
2907 zone_alloc_item_locked(uma_zone_t zone, void *udata, int domain, int flags)
2908 {
2909 	void *item;
2910 #ifdef INVARIANTS
2911 	bool skipdbg;
2912 #endif
2913 
2914 	ZONE_LOCK_ASSERT(zone);
2915 
2916 	if (zone->uz_max_items > 0) {
2917 		if (zone->uz_items >= zone->uz_max_items) {
2918 			zone_log_warning(zone);
2919 			zone_maxaction(zone);
2920 			if (flags & M_NOWAIT) {
2921 				ZONE_UNLOCK(zone);
2922 				return (NULL);
2923 			}
2924 			zone->uz_sleeps++;
2925 			zone->uz_sleepers++;
2926 			while (zone->uz_items >= zone->uz_max_items)
2927 				mtx_sleep(zone, zone->uz_lockptr, PVM,
2928 				    "zonelimit", 0);
2929 			zone->uz_sleepers--;
2930 			if (zone->uz_sleepers > 0 &&
2931 			    zone->uz_items + 1 < zone->uz_max_items)
2932 				wakeup_one(zone);
2933 		}
2934 		zone->uz_items++;
2935 	}
2936 	ZONE_UNLOCK(zone);
2937 
2938 	if (domain != UMA_ANYDOMAIN) {
2939 		/* avoid allocs targeting empty domains */
2940 		if (VM_DOMAIN_EMPTY(domain))
2941 			domain = UMA_ANYDOMAIN;
2942 	}
2943 	if (zone->uz_import(zone->uz_arg, &item, 1, domain, flags) != 1)
2944 		goto fail;
2945 
2946 #ifdef INVARIANTS
2947 	skipdbg = uma_dbg_zskip(zone, item);
2948 #endif
2949 	/*
2950 	 * We have to call both the zone's init (not the keg's init)
2951 	 * and the zone's ctor.  This is because the item is going from
2952 	 * a keg slab directly to the user, and the user is expecting it
2953 	 * to be both zone-init'd as well as zone-ctor'd.
2954 	 */
2955 	if (zone->uz_init != NULL) {
2956 		if (zone->uz_init(item, zone->uz_size, flags) != 0) {
2957 			zone_free_item(zone, item, udata, SKIP_FINI | SKIP_CNT);
2958 			goto fail;
2959 		}
2960 	}
2961 	if (zone->uz_ctor != NULL &&
2962 #ifdef INVARIANTS
2963 	    (!skipdbg || zone->uz_ctor != trash_ctor ||
2964 	    zone->uz_dtor != trash_dtor) &&
2965 #endif
2966 	    zone->uz_ctor(item, zone->uz_size, udata, flags) != 0) {
2967 		zone_free_item(zone, item, udata, SKIP_DTOR | SKIP_CNT);
2968 		goto fail;
2969 	}
2970 #ifdef INVARIANTS
2971 	if (!skipdbg)
2972 		uma_dbg_alloc(zone, NULL, item);
2973 #endif
2974 	if (flags & M_ZERO)
2975 		uma_zero_item(item, zone);
2976 
2977 	counter_u64_add(zone->uz_allocs, 1);
2978 	CTR3(KTR_UMA, "zone_alloc_item item %p from %s(%p)", item,
2979 	    zone->uz_name, zone);
2980 
2981 	return (item);
2982 
2983 fail:
2984 	if (zone->uz_max_items > 0) {
2985 		ZONE_LOCK(zone);
2986 		zone->uz_items--;
2987 		ZONE_UNLOCK(zone);
2988 	}
2989 	counter_u64_add(zone->uz_fails, 1);
2990 	CTR2(KTR_UMA, "zone_alloc_item failed from %s(%p)",
2991 	    zone->uz_name, zone);
2992 	return (NULL);
2993 }
2994 
2995 /* See uma.h */
2996 void
2997 uma_zfree_arg(uma_zone_t zone, void *item, void *udata)
2998 {
2999 	uma_cache_t cache;
3000 	uma_bucket_t bucket;
3001 	uma_zone_domain_t zdom;
3002 	int cpu, domain;
3003 	bool lockfail;
3004 #ifdef INVARIANTS
3005 	bool skipdbg;
3006 #endif
3007 
3008 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
3009 	random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
3010 
3011 	CTR2(KTR_UMA, "uma_zfree_arg thread %x zone %s", curthread,
3012 	    zone->uz_name);
3013 
3014 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
3015 	    ("uma_zfree_arg: called with spinlock or critical section held"));
3016 
3017         /* uma_zfree(..., NULL) does nothing, to match free(9). */
3018         if (item == NULL)
3019                 return;
3020 #ifdef DEBUG_MEMGUARD
3021 	if (is_memguard_addr(item)) {
3022 		if (zone->uz_dtor != NULL)
3023 			zone->uz_dtor(item, zone->uz_size, udata);
3024 		if (zone->uz_fini != NULL)
3025 			zone->uz_fini(item, zone->uz_size);
3026 		memguard_free(item);
3027 		return;
3028 	}
3029 #endif
3030 #ifdef INVARIANTS
3031 	skipdbg = uma_dbg_zskip(zone, item);
3032 	if (skipdbg == false) {
3033 		if (zone->uz_flags & UMA_ZONE_MALLOC)
3034 			uma_dbg_free(zone, udata, item);
3035 		else
3036 			uma_dbg_free(zone, NULL, item);
3037 	}
3038 	if (zone->uz_dtor != NULL && (!skipdbg ||
3039 	    zone->uz_dtor != trash_dtor || zone->uz_ctor != trash_ctor))
3040 #else
3041 	if (zone->uz_dtor != NULL)
3042 #endif
3043 		zone->uz_dtor(item, zone->uz_size, udata);
3044 
3045 	/*
3046 	 * The race here is acceptable.  If we miss it we'll just have to wait
3047 	 * a little longer for the limits to be reset.
3048 	 */
3049 	if (zone->uz_sleepers > 0)
3050 		goto zfree_item;
3051 
3052 	/*
3053 	 * If possible, free to the per-CPU cache.  There are two
3054 	 * requirements for safe access to the per-CPU cache: (1) the thread
3055 	 * accessing the cache must not be preempted or yield during access,
3056 	 * and (2) the thread must not migrate CPUs without switching which
3057 	 * cache it accesses.  We rely on a critical section to prevent
3058 	 * preemption and migration.  We release the critical section in
3059 	 * order to acquire the zone mutex if we are unable to free to the
3060 	 * current cache; when we re-acquire the critical section, we must
3061 	 * detect and handle migration if it has occurred.
3062 	 */
3063 zfree_restart:
3064 	critical_enter();
3065 	cpu = curcpu;
3066 	cache = &zone->uz_cpu[cpu];
3067 
3068 zfree_start:
3069 	/*
3070 	 * Try to free into the allocbucket first to give LIFO ordering
3071 	 * for cache-hot datastructures.  Spill over into the freebucket
3072 	 * if necessary.  Alloc will swap them if one runs dry.
3073 	 */
3074 	bucket = cache->uc_allocbucket;
3075 	if (bucket == NULL || bucket->ub_cnt >= bucket->ub_entries)
3076 		bucket = cache->uc_freebucket;
3077 	if (bucket != NULL && bucket->ub_cnt < bucket->ub_entries) {
3078 		KASSERT(bucket->ub_bucket[bucket->ub_cnt] == NULL,
3079 		    ("uma_zfree: Freeing to non free bucket index."));
3080 		bucket->ub_bucket[bucket->ub_cnt] = item;
3081 		bucket->ub_cnt++;
3082 		cache->uc_frees++;
3083 		critical_exit();
3084 		return;
3085 	}
3086 
3087 	/*
3088 	 * We must go back the zone, which requires acquiring the zone lock,
3089 	 * which in turn means we must release and re-acquire the critical
3090 	 * section.  Since the critical section is released, we may be
3091 	 * preempted or migrate.  As such, make sure not to maintain any
3092 	 * thread-local state specific to the cache from prior to releasing
3093 	 * the critical section.
3094 	 */
3095 	critical_exit();
3096 	if (zone->uz_count == 0 || bucketdisable)
3097 		goto zfree_item;
3098 
3099 	lockfail = false;
3100 	if (ZONE_TRYLOCK(zone) == 0) {
3101 		/* Record contention to size the buckets. */
3102 		ZONE_LOCK(zone);
3103 		lockfail = true;
3104 	}
3105 	critical_enter();
3106 	cpu = curcpu;
3107 	cache = &zone->uz_cpu[cpu];
3108 
3109 	bucket = cache->uc_freebucket;
3110 	if (bucket != NULL && bucket->ub_cnt < bucket->ub_entries) {
3111 		ZONE_UNLOCK(zone);
3112 		goto zfree_start;
3113 	}
3114 	cache->uc_freebucket = NULL;
3115 	/* We are no longer associated with this CPU. */
3116 	critical_exit();
3117 
3118 	if ((zone->uz_flags & UMA_ZONE_NUMA) != 0) {
3119 		domain = PCPU_GET(domain);
3120 		if (VM_DOMAIN_EMPTY(domain))
3121 			domain = UMA_ANYDOMAIN;
3122 	} else
3123 		domain = 0;
3124 	zdom = &zone->uz_domain[0];
3125 
3126 	/* Can we throw this on the zone full list? */
3127 	if (bucket != NULL) {
3128 		CTR3(KTR_UMA,
3129 		    "uma_zfree: zone %s(%p) putting bucket %p on free list",
3130 		    zone->uz_name, zone, bucket);
3131 		/* ub_cnt is pointing to the last free item */
3132 		KASSERT(bucket->ub_cnt == bucket->ub_entries,
3133 		    ("uma_zfree: Attempting to insert not full bucket onto the full list.\n"));
3134 		if (zone->uz_bkt_count >= zone->uz_bkt_max) {
3135 			ZONE_UNLOCK(zone);
3136 			bucket_drain(zone, bucket);
3137 			bucket_free(zone, bucket, udata);
3138 			goto zfree_restart;
3139 		} else
3140 			zone_put_bucket(zone, zdom, bucket, true);
3141 	}
3142 
3143 	/*
3144 	 * We bump the uz count when the cache size is insufficient to
3145 	 * handle the working set.
3146 	 */
3147 	if (lockfail && zone->uz_count < zone->uz_count_max)
3148 		zone->uz_count++;
3149 	ZONE_UNLOCK(zone);
3150 
3151 	bucket = bucket_alloc(zone, udata, M_NOWAIT);
3152 	CTR3(KTR_UMA, "uma_zfree: zone %s(%p) allocated bucket %p",
3153 	    zone->uz_name, zone, bucket);
3154 	if (bucket) {
3155 		critical_enter();
3156 		cpu = curcpu;
3157 		cache = &zone->uz_cpu[cpu];
3158 		if (cache->uc_freebucket == NULL &&
3159 		    ((zone->uz_flags & UMA_ZONE_NUMA) == 0 ||
3160 		    domain == PCPU_GET(domain))) {
3161 			cache->uc_freebucket = bucket;
3162 			goto zfree_start;
3163 		}
3164 		/*
3165 		 * We lost the race, start over.  We have to drop our
3166 		 * critical section to free the bucket.
3167 		 */
3168 		critical_exit();
3169 		bucket_free(zone, bucket, udata);
3170 		goto zfree_restart;
3171 	}
3172 
3173 	/*
3174 	 * If nothing else caught this, we'll just do an internal free.
3175 	 */
3176 zfree_item:
3177 	zone_free_item(zone, item, udata, SKIP_DTOR);
3178 }
3179 
3180 void
3181 uma_zfree_domain(uma_zone_t zone, void *item, void *udata)
3182 {
3183 
3184 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
3185 	random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
3186 
3187 	CTR2(KTR_UMA, "uma_zfree_domain thread %x zone %s", curthread,
3188 	    zone->uz_name);
3189 
3190 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
3191 	    ("uma_zfree_domain: called with spinlock or critical section held"));
3192 
3193         /* uma_zfree(..., NULL) does nothing, to match free(9). */
3194         if (item == NULL)
3195                 return;
3196 	zone_free_item(zone, item, udata, SKIP_NONE);
3197 }
3198 
3199 static void
3200 slab_free_item(uma_zone_t zone, uma_slab_t slab, void *item)
3201 {
3202 	uma_keg_t keg;
3203 	uma_domain_t dom;
3204 	uint8_t freei;
3205 
3206 	keg = zone->uz_keg;
3207 	MPASS(zone->uz_lockptr == &keg->uk_lock);
3208 	KEG_LOCK_ASSERT(keg);
3209 	MPASS(keg == slab->us_keg);
3210 
3211 	dom = &keg->uk_domain[slab->us_domain];
3212 
3213 	/* Do we need to remove from any lists? */
3214 	if (slab->us_freecount+1 == keg->uk_ipers) {
3215 		LIST_REMOVE(slab, us_link);
3216 		LIST_INSERT_HEAD(&dom->ud_free_slab, slab, us_link);
3217 	} else if (slab->us_freecount == 0) {
3218 		LIST_REMOVE(slab, us_link);
3219 		LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
3220 	}
3221 
3222 	/* Slab management. */
3223 	freei = ((uintptr_t)item - (uintptr_t)slab->us_data) / keg->uk_rsize;
3224 	BIT_SET(SLAB_SETSIZE, freei, &slab->us_free);
3225 	slab->us_freecount++;
3226 
3227 	/* Keg statistics. */
3228 	keg->uk_free++;
3229 }
3230 
3231 static void
3232 zone_release(uma_zone_t zone, void **bucket, int cnt)
3233 {
3234 	void *item;
3235 	uma_slab_t slab;
3236 	uma_keg_t keg;
3237 	uint8_t *mem;
3238 	int i;
3239 
3240 	keg = zone->uz_keg;
3241 	KEG_LOCK(keg);
3242 	for (i = 0; i < cnt; i++) {
3243 		item = bucket[i];
3244 		if (!(zone->uz_flags & UMA_ZONE_VTOSLAB)) {
3245 			mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
3246 			if (zone->uz_flags & UMA_ZONE_HASH) {
3247 				slab = hash_sfind(&keg->uk_hash, mem);
3248 			} else {
3249 				mem += keg->uk_pgoff;
3250 				slab = (uma_slab_t)mem;
3251 			}
3252 		} else {
3253 			slab = vtoslab((vm_offset_t)item);
3254 			MPASS(slab->us_keg == keg);
3255 		}
3256 		slab_free_item(zone, slab, item);
3257 	}
3258 	KEG_UNLOCK(keg);
3259 }
3260 
3261 /*
3262  * Frees a single item to any zone.
3263  *
3264  * Arguments:
3265  *	zone   The zone to free to
3266  *	item   The item we're freeing
3267  *	udata  User supplied data for the dtor
3268  *	skip   Skip dtors and finis
3269  */
3270 static void
3271 zone_free_item(uma_zone_t zone, void *item, void *udata, enum zfreeskip skip)
3272 {
3273 #ifdef INVARIANTS
3274 	bool skipdbg;
3275 
3276 	skipdbg = uma_dbg_zskip(zone, item);
3277 	if (skip == SKIP_NONE && !skipdbg) {
3278 		if (zone->uz_flags & UMA_ZONE_MALLOC)
3279 			uma_dbg_free(zone, udata, item);
3280 		else
3281 			uma_dbg_free(zone, NULL, item);
3282 	}
3283 
3284 	if (skip < SKIP_DTOR && zone->uz_dtor != NULL &&
3285 	    (!skipdbg || zone->uz_dtor != trash_dtor ||
3286 	    zone->uz_ctor != trash_ctor))
3287 #else
3288 	if (skip < SKIP_DTOR && zone->uz_dtor != NULL)
3289 #endif
3290 		zone->uz_dtor(item, zone->uz_size, udata);
3291 
3292 	if (skip < SKIP_FINI && zone->uz_fini)
3293 		zone->uz_fini(item, zone->uz_size);
3294 
3295 	zone->uz_release(zone->uz_arg, &item, 1);
3296 
3297 	if (skip & SKIP_CNT)
3298 		return;
3299 
3300 	counter_u64_add(zone->uz_frees, 1);
3301 
3302 	if (zone->uz_max_items > 0) {
3303 		ZONE_LOCK(zone);
3304 		zone->uz_items--;
3305 		if (zone->uz_sleepers > 0 &&
3306 		    zone->uz_items < zone->uz_max_items)
3307 			wakeup_one(zone);
3308 		ZONE_UNLOCK(zone);
3309 	}
3310 }
3311 
3312 /* See uma.h */
3313 int
3314 uma_zone_set_max(uma_zone_t zone, int nitems)
3315 {
3316 	struct uma_bucket_zone *ubz;
3317 
3318 	/*
3319 	 * If limit is very low we may need to limit how
3320 	 * much items are allowed in CPU caches.
3321 	 */
3322 	ubz = &bucket_zones[0];
3323 	for (; ubz->ubz_entries != 0; ubz++)
3324 		if (ubz->ubz_entries * 2 * mp_ncpus > nitems)
3325 			break;
3326 	if (ubz == &bucket_zones[0])
3327 		nitems = ubz->ubz_entries * 2 * mp_ncpus;
3328 	else
3329 		ubz--;
3330 
3331 	ZONE_LOCK(zone);
3332 	zone->uz_count_max = zone->uz_count = ubz->ubz_entries;
3333 	if (zone->uz_count_min > zone->uz_count_max)
3334 		zone->uz_count_min = zone->uz_count_max;
3335 	zone->uz_max_items = nitems;
3336 	ZONE_UNLOCK(zone);
3337 
3338 	return (nitems);
3339 }
3340 
3341 /* See uma.h */
3342 int
3343 uma_zone_set_maxcache(uma_zone_t zone, int nitems)
3344 {
3345 
3346 	ZONE_LOCK(zone);
3347 	zone->uz_bkt_max = nitems;
3348 	ZONE_UNLOCK(zone);
3349 
3350 	return (nitems);
3351 }
3352 
3353 /* See uma.h */
3354 int
3355 uma_zone_get_max(uma_zone_t zone)
3356 {
3357 	int nitems;
3358 
3359 	ZONE_LOCK(zone);
3360 	nitems = zone->uz_max_items;
3361 	ZONE_UNLOCK(zone);
3362 
3363 	return (nitems);
3364 }
3365 
3366 /* See uma.h */
3367 void
3368 uma_zone_set_warning(uma_zone_t zone, const char *warning)
3369 {
3370 
3371 	ZONE_LOCK(zone);
3372 	zone->uz_warning = warning;
3373 	ZONE_UNLOCK(zone);
3374 }
3375 
3376 /* See uma.h */
3377 void
3378 uma_zone_set_maxaction(uma_zone_t zone, uma_maxaction_t maxaction)
3379 {
3380 
3381 	ZONE_LOCK(zone);
3382 	TASK_INIT(&zone->uz_maxaction, 0, (task_fn_t *)maxaction, zone);
3383 	ZONE_UNLOCK(zone);
3384 }
3385 
3386 /* See uma.h */
3387 int
3388 uma_zone_get_cur(uma_zone_t zone)
3389 {
3390 	int64_t nitems;
3391 	u_int i;
3392 
3393 	ZONE_LOCK(zone);
3394 	nitems = counter_u64_fetch(zone->uz_allocs) -
3395 	    counter_u64_fetch(zone->uz_frees);
3396 	CPU_FOREACH(i) {
3397 		/*
3398 		 * See the comment in sysctl_vm_zone_stats() regarding the
3399 		 * safety of accessing the per-cpu caches. With the zone lock
3400 		 * held, it is safe, but can potentially result in stale data.
3401 		 */
3402 		nitems += zone->uz_cpu[i].uc_allocs -
3403 		    zone->uz_cpu[i].uc_frees;
3404 	}
3405 	ZONE_UNLOCK(zone);
3406 
3407 	return (nitems < 0 ? 0 : nitems);
3408 }
3409 
3410 /* See uma.h */
3411 void
3412 uma_zone_set_init(uma_zone_t zone, uma_init uminit)
3413 {
3414 	uma_keg_t keg;
3415 
3416 	KEG_GET(zone, keg);
3417 	KEG_LOCK(keg);
3418 	KASSERT(keg->uk_pages == 0,
3419 	    ("uma_zone_set_init on non-empty keg"));
3420 	keg->uk_init = uminit;
3421 	KEG_UNLOCK(keg);
3422 }
3423 
3424 /* See uma.h */
3425 void
3426 uma_zone_set_fini(uma_zone_t zone, uma_fini fini)
3427 {
3428 	uma_keg_t keg;
3429 
3430 	KEG_GET(zone, keg);
3431 	KEG_LOCK(keg);
3432 	KASSERT(keg->uk_pages == 0,
3433 	    ("uma_zone_set_fini on non-empty keg"));
3434 	keg->uk_fini = fini;
3435 	KEG_UNLOCK(keg);
3436 }
3437 
3438 /* See uma.h */
3439 void
3440 uma_zone_set_zinit(uma_zone_t zone, uma_init zinit)
3441 {
3442 
3443 	ZONE_LOCK(zone);
3444 	KASSERT(zone->uz_keg->uk_pages == 0,
3445 	    ("uma_zone_set_zinit on non-empty keg"));
3446 	zone->uz_init = zinit;
3447 	ZONE_UNLOCK(zone);
3448 }
3449 
3450 /* See uma.h */
3451 void
3452 uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini)
3453 {
3454 
3455 	ZONE_LOCK(zone);
3456 	KASSERT(zone->uz_keg->uk_pages == 0,
3457 	    ("uma_zone_set_zfini on non-empty keg"));
3458 	zone->uz_fini = zfini;
3459 	ZONE_UNLOCK(zone);
3460 }
3461 
3462 /* See uma.h */
3463 /* XXX uk_freef is not actually used with the zone locked */
3464 void
3465 uma_zone_set_freef(uma_zone_t zone, uma_free freef)
3466 {
3467 	uma_keg_t keg;
3468 
3469 	KEG_GET(zone, keg);
3470 	KASSERT(keg != NULL, ("uma_zone_set_freef: Invalid zone type"));
3471 	KEG_LOCK(keg);
3472 	keg->uk_freef = freef;
3473 	KEG_UNLOCK(keg);
3474 }
3475 
3476 /* See uma.h */
3477 /* XXX uk_allocf is not actually used with the zone locked */
3478 void
3479 uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf)
3480 {
3481 	uma_keg_t keg;
3482 
3483 	KEG_GET(zone, keg);
3484 	KEG_LOCK(keg);
3485 	keg->uk_allocf = allocf;
3486 	KEG_UNLOCK(keg);
3487 }
3488 
3489 /* See uma.h */
3490 void
3491 uma_zone_reserve(uma_zone_t zone, int items)
3492 {
3493 	uma_keg_t keg;
3494 
3495 	KEG_GET(zone, keg);
3496 	KEG_LOCK(keg);
3497 	keg->uk_reserve = items;
3498 	KEG_UNLOCK(keg);
3499 }
3500 
3501 /* See uma.h */
3502 int
3503 uma_zone_reserve_kva(uma_zone_t zone, int count)
3504 {
3505 	uma_keg_t keg;
3506 	vm_offset_t kva;
3507 	u_int pages;
3508 
3509 	KEG_GET(zone, keg);
3510 
3511 	pages = count / keg->uk_ipers;
3512 	if (pages * keg->uk_ipers < count)
3513 		pages++;
3514 	pages *= keg->uk_ppera;
3515 
3516 #ifdef UMA_MD_SMALL_ALLOC
3517 	if (keg->uk_ppera > 1) {
3518 #else
3519 	if (1) {
3520 #endif
3521 		kva = kva_alloc((vm_size_t)pages * PAGE_SIZE);
3522 		if (kva == 0)
3523 			return (0);
3524 	} else
3525 		kva = 0;
3526 
3527 	ZONE_LOCK(zone);
3528 	MPASS(keg->uk_kva == 0);
3529 	keg->uk_kva = kva;
3530 	keg->uk_offset = 0;
3531 	zone->uz_max_items = pages * keg->uk_ipers;
3532 #ifdef UMA_MD_SMALL_ALLOC
3533 	keg->uk_allocf = (keg->uk_ppera > 1) ? noobj_alloc : uma_small_alloc;
3534 #else
3535 	keg->uk_allocf = noobj_alloc;
3536 #endif
3537 	keg->uk_flags |= UMA_ZONE_NOFREE;
3538 	ZONE_UNLOCK(zone);
3539 
3540 	return (1);
3541 }
3542 
3543 /* See uma.h */
3544 void
3545 uma_prealloc(uma_zone_t zone, int items)
3546 {
3547 	struct vm_domainset_iter di;
3548 	uma_domain_t dom;
3549 	uma_slab_t slab;
3550 	uma_keg_t keg;
3551 	int domain, flags, slabs;
3552 
3553 	KEG_GET(zone, keg);
3554 	KEG_LOCK(keg);
3555 	slabs = items / keg->uk_ipers;
3556 	if (slabs * keg->uk_ipers < items)
3557 		slabs++;
3558 	flags = M_WAITOK;
3559 	vm_domainset_iter_policy_ref_init(&di, &keg->uk_dr, &domain, &flags);
3560 	while (slabs-- > 0) {
3561 		slab = keg_alloc_slab(keg, zone, domain, flags);
3562 		if (slab == NULL)
3563 			return;
3564 		MPASS(slab->us_keg == keg);
3565 		dom = &keg->uk_domain[slab->us_domain];
3566 		LIST_INSERT_HEAD(&dom->ud_free_slab, slab, us_link);
3567 		if (vm_domainset_iter_policy(&di, &domain) != 0)
3568 			break;
3569 	}
3570 	KEG_UNLOCK(keg);
3571 }
3572 
3573 /* See uma.h */
3574 static void
3575 uma_reclaim_locked(bool kmem_danger)
3576 {
3577 
3578 	CTR0(KTR_UMA, "UMA: vm asked us to release pages!");
3579 	sx_assert(&uma_drain_lock, SA_XLOCKED);
3580 	bucket_enable();
3581 	zone_foreach(zone_drain);
3582 	if (vm_page_count_min() || kmem_danger) {
3583 		cache_drain_safe(NULL);
3584 		zone_foreach(zone_drain);
3585 	}
3586 
3587 	/*
3588 	 * Some slabs may have been freed but this zone will be visited early
3589 	 * we visit again so that we can free pages that are empty once other
3590 	 * zones are drained.  We have to do the same for buckets.
3591 	 */
3592 	zone_drain(slabzone);
3593 	bucket_zone_drain();
3594 }
3595 
3596 void
3597 uma_reclaim(void)
3598 {
3599 
3600 	sx_xlock(&uma_drain_lock);
3601 	uma_reclaim_locked(false);
3602 	sx_xunlock(&uma_drain_lock);
3603 }
3604 
3605 static volatile int uma_reclaim_needed;
3606 
3607 void
3608 uma_reclaim_wakeup(void)
3609 {
3610 
3611 	if (atomic_fetchadd_int(&uma_reclaim_needed, 1) == 0)
3612 		wakeup(uma_reclaim);
3613 }
3614 
3615 void
3616 uma_reclaim_worker(void *arg __unused)
3617 {
3618 
3619 	for (;;) {
3620 		sx_xlock(&uma_drain_lock);
3621 		while (atomic_load_int(&uma_reclaim_needed) == 0)
3622 			sx_sleep(uma_reclaim, &uma_drain_lock, PVM, "umarcl",
3623 			    hz);
3624 		sx_xunlock(&uma_drain_lock);
3625 		EVENTHANDLER_INVOKE(vm_lowmem, VM_LOW_KMEM);
3626 		sx_xlock(&uma_drain_lock);
3627 		uma_reclaim_locked(true);
3628 		atomic_store_int(&uma_reclaim_needed, 0);
3629 		sx_xunlock(&uma_drain_lock);
3630 		/* Don't fire more than once per-second. */
3631 		pause("umarclslp", hz);
3632 	}
3633 }
3634 
3635 /* See uma.h */
3636 int
3637 uma_zone_exhausted(uma_zone_t zone)
3638 {
3639 	int full;
3640 
3641 	ZONE_LOCK(zone);
3642 	full = zone->uz_sleepers > 0;
3643 	ZONE_UNLOCK(zone);
3644 	return (full);
3645 }
3646 
3647 int
3648 uma_zone_exhausted_nolock(uma_zone_t zone)
3649 {
3650 	return (zone->uz_sleepers > 0);
3651 }
3652 
3653 void *
3654 uma_large_malloc_domain(vm_size_t size, int domain, int wait)
3655 {
3656 	struct domainset *policy;
3657 	vm_offset_t addr;
3658 	uma_slab_t slab;
3659 
3660 	if (domain != UMA_ANYDOMAIN) {
3661 		/* avoid allocs targeting empty domains */
3662 		if (VM_DOMAIN_EMPTY(domain))
3663 			domain = UMA_ANYDOMAIN;
3664 	}
3665 	slab = zone_alloc_item(slabzone, NULL, domain, wait);
3666 	if (slab == NULL)
3667 		return (NULL);
3668 	policy = (domain == UMA_ANYDOMAIN) ? DOMAINSET_RR() :
3669 	    DOMAINSET_FIXED(domain);
3670 	addr = kmem_malloc_domainset(policy, size, wait);
3671 	if (addr != 0) {
3672 		vsetslab(addr, slab);
3673 		slab->us_data = (void *)addr;
3674 		slab->us_flags = UMA_SLAB_KERNEL | UMA_SLAB_MALLOC;
3675 		slab->us_size = size;
3676 		slab->us_domain = vm_phys_domain(PHYS_TO_VM_PAGE(
3677 		    pmap_kextract(addr)));
3678 		uma_total_inc(size);
3679 	} else {
3680 		zone_free_item(slabzone, slab, NULL, SKIP_NONE);
3681 	}
3682 
3683 	return ((void *)addr);
3684 }
3685 
3686 void *
3687 uma_large_malloc(vm_size_t size, int wait)
3688 {
3689 
3690 	return uma_large_malloc_domain(size, UMA_ANYDOMAIN, wait);
3691 }
3692 
3693 void
3694 uma_large_free(uma_slab_t slab)
3695 {
3696 
3697 	KASSERT((slab->us_flags & UMA_SLAB_KERNEL) != 0,
3698 	    ("uma_large_free:  Memory not allocated with uma_large_malloc."));
3699 	kmem_free((vm_offset_t)slab->us_data, slab->us_size);
3700 	uma_total_dec(slab->us_size);
3701 	zone_free_item(slabzone, slab, NULL, SKIP_NONE);
3702 }
3703 
3704 static void
3705 uma_zero_item(void *item, uma_zone_t zone)
3706 {
3707 
3708 	bzero(item, zone->uz_size);
3709 }
3710 
3711 unsigned long
3712 uma_limit(void)
3713 {
3714 
3715 	return (uma_kmem_limit);
3716 }
3717 
3718 void
3719 uma_set_limit(unsigned long limit)
3720 {
3721 
3722 	uma_kmem_limit = limit;
3723 }
3724 
3725 unsigned long
3726 uma_size(void)
3727 {
3728 
3729 	return (uma_kmem_total);
3730 }
3731 
3732 long
3733 uma_avail(void)
3734 {
3735 
3736 	return (uma_kmem_limit - uma_kmem_total);
3737 }
3738 
3739 void
3740 uma_print_stats(void)
3741 {
3742 	zone_foreach(uma_print_zone);
3743 }
3744 
3745 static void
3746 slab_print(uma_slab_t slab)
3747 {
3748 	printf("slab: keg %p, data %p, freecount %d\n",
3749 		slab->us_keg, slab->us_data, slab->us_freecount);
3750 }
3751 
3752 static void
3753 cache_print(uma_cache_t cache)
3754 {
3755 	printf("alloc: %p(%d), free: %p(%d)\n",
3756 		cache->uc_allocbucket,
3757 		cache->uc_allocbucket?cache->uc_allocbucket->ub_cnt:0,
3758 		cache->uc_freebucket,
3759 		cache->uc_freebucket?cache->uc_freebucket->ub_cnt:0);
3760 }
3761 
3762 static void
3763 uma_print_keg(uma_keg_t keg)
3764 {
3765 	uma_domain_t dom;
3766 	uma_slab_t slab;
3767 	int i;
3768 
3769 	printf("keg: %s(%p) size %d(%d) flags %#x ipers %d ppera %d "
3770 	    "out %d free %d\n",
3771 	    keg->uk_name, keg, keg->uk_size, keg->uk_rsize, keg->uk_flags,
3772 	    keg->uk_ipers, keg->uk_ppera,
3773 	    (keg->uk_pages / keg->uk_ppera) * keg->uk_ipers - keg->uk_free,
3774 	    keg->uk_free);
3775 	for (i = 0; i < vm_ndomains; i++) {
3776 		dom = &keg->uk_domain[i];
3777 		printf("Part slabs:\n");
3778 		LIST_FOREACH(slab, &dom->ud_part_slab, us_link)
3779 			slab_print(slab);
3780 		printf("Free slabs:\n");
3781 		LIST_FOREACH(slab, &dom->ud_free_slab, us_link)
3782 			slab_print(slab);
3783 		printf("Full slabs:\n");
3784 		LIST_FOREACH(slab, &dom->ud_full_slab, us_link)
3785 			slab_print(slab);
3786 	}
3787 }
3788 
3789 void
3790 uma_print_zone(uma_zone_t zone)
3791 {
3792 	uma_cache_t cache;
3793 	int i;
3794 
3795 	printf("zone: %s(%p) size %d maxitems %ju flags %#x\n",
3796 	    zone->uz_name, zone, zone->uz_size, (uintmax_t)zone->uz_max_items,
3797 	    zone->uz_flags);
3798 	if (zone->uz_lockptr != &zone->uz_lock)
3799 		uma_print_keg(zone->uz_keg);
3800 	CPU_FOREACH(i) {
3801 		cache = &zone->uz_cpu[i];
3802 		printf("CPU %d Cache:\n", i);
3803 		cache_print(cache);
3804 	}
3805 }
3806 
3807 #ifdef DDB
3808 /*
3809  * Generate statistics across both the zone and its per-cpu cache's.  Return
3810  * desired statistics if the pointer is non-NULL for that statistic.
3811  *
3812  * Note: does not update the zone statistics, as it can't safely clear the
3813  * per-CPU cache statistic.
3814  *
3815  * XXXRW: Following the uc_allocbucket and uc_freebucket pointers here isn't
3816  * safe from off-CPU; we should modify the caches to track this information
3817  * directly so that we don't have to.
3818  */
3819 static void
3820 uma_zone_sumstat(uma_zone_t z, long *cachefreep, uint64_t *allocsp,
3821     uint64_t *freesp, uint64_t *sleepsp)
3822 {
3823 	uma_cache_t cache;
3824 	uint64_t allocs, frees, sleeps;
3825 	int cachefree, cpu;
3826 
3827 	allocs = frees = sleeps = 0;
3828 	cachefree = 0;
3829 	CPU_FOREACH(cpu) {
3830 		cache = &z->uz_cpu[cpu];
3831 		if (cache->uc_allocbucket != NULL)
3832 			cachefree += cache->uc_allocbucket->ub_cnt;
3833 		if (cache->uc_freebucket != NULL)
3834 			cachefree += cache->uc_freebucket->ub_cnt;
3835 		allocs += cache->uc_allocs;
3836 		frees += cache->uc_frees;
3837 	}
3838 	allocs += counter_u64_fetch(z->uz_allocs);
3839 	frees += counter_u64_fetch(z->uz_frees);
3840 	sleeps += z->uz_sleeps;
3841 	if (cachefreep != NULL)
3842 		*cachefreep = cachefree;
3843 	if (allocsp != NULL)
3844 		*allocsp = allocs;
3845 	if (freesp != NULL)
3846 		*freesp = frees;
3847 	if (sleepsp != NULL)
3848 		*sleepsp = sleeps;
3849 }
3850 #endif /* DDB */
3851 
3852 static int
3853 sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS)
3854 {
3855 	uma_keg_t kz;
3856 	uma_zone_t z;
3857 	int count;
3858 
3859 	count = 0;
3860 	rw_rlock(&uma_rwlock);
3861 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3862 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
3863 			count++;
3864 	}
3865 	rw_runlock(&uma_rwlock);
3866 	return (sysctl_handle_int(oidp, &count, 0, req));
3867 }
3868 
3869 static int
3870 sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS)
3871 {
3872 	struct uma_stream_header ush;
3873 	struct uma_type_header uth;
3874 	struct uma_percpu_stat *ups;
3875 	uma_zone_domain_t zdom;
3876 	struct sbuf sbuf;
3877 	uma_cache_t cache;
3878 	uma_keg_t kz;
3879 	uma_zone_t z;
3880 	int count, error, i;
3881 
3882 	error = sysctl_wire_old_buffer(req, 0);
3883 	if (error != 0)
3884 		return (error);
3885 	sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
3886 	sbuf_clear_flags(&sbuf, SBUF_INCLUDENUL);
3887 	ups = malloc((mp_maxid + 1) * sizeof(*ups), M_TEMP, M_WAITOK);
3888 
3889 	count = 0;
3890 	rw_rlock(&uma_rwlock);
3891 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3892 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
3893 			count++;
3894 	}
3895 
3896 	/*
3897 	 * Insert stream header.
3898 	 */
3899 	bzero(&ush, sizeof(ush));
3900 	ush.ush_version = UMA_STREAM_VERSION;
3901 	ush.ush_maxcpus = (mp_maxid + 1);
3902 	ush.ush_count = count;
3903 	(void)sbuf_bcat(&sbuf, &ush, sizeof(ush));
3904 
3905 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3906 		LIST_FOREACH(z, &kz->uk_zones, uz_link) {
3907 			bzero(&uth, sizeof(uth));
3908 			ZONE_LOCK(z);
3909 			strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
3910 			uth.uth_align = kz->uk_align;
3911 			uth.uth_size = kz->uk_size;
3912 			uth.uth_rsize = kz->uk_rsize;
3913 			if (z->uz_max_items > 0)
3914 				uth.uth_pages = (z->uz_items / kz->uk_ipers) *
3915 					kz->uk_ppera;
3916 			else
3917 				uth.uth_pages = kz->uk_pages;
3918 			uth.uth_maxpages = (z->uz_max_items / kz->uk_ipers) *
3919 			    kz->uk_ppera;
3920 			uth.uth_limit = z->uz_max_items;
3921 			uth.uth_keg_free = z->uz_keg->uk_free;
3922 
3923 			/*
3924 			 * A zone is secondary is it is not the first entry
3925 			 * on the keg's zone list.
3926 			 */
3927 			if ((z->uz_flags & UMA_ZONE_SECONDARY) &&
3928 			    (LIST_FIRST(&kz->uk_zones) != z))
3929 				uth.uth_zone_flags = UTH_ZONE_SECONDARY;
3930 
3931 			for (i = 0; i < vm_ndomains; i++) {
3932 				zdom = &z->uz_domain[i];
3933 				uth.uth_zone_free += zdom->uzd_nitems;
3934 			}
3935 			uth.uth_allocs = counter_u64_fetch(z->uz_allocs);
3936 			uth.uth_frees = counter_u64_fetch(z->uz_frees);
3937 			uth.uth_fails = counter_u64_fetch(z->uz_fails);
3938 			uth.uth_sleeps = z->uz_sleeps;
3939 			/*
3940 			 * While it is not normally safe to access the cache
3941 			 * bucket pointers while not on the CPU that owns the
3942 			 * cache, we only allow the pointers to be exchanged
3943 			 * without the zone lock held, not invalidated, so
3944 			 * accept the possible race associated with bucket
3945 			 * exchange during monitoring.
3946 			 */
3947 			for (i = 0; i < mp_maxid + 1; i++) {
3948 				bzero(&ups[i], sizeof(*ups));
3949 				if (kz->uk_flags & UMA_ZFLAG_INTERNAL ||
3950 				    CPU_ABSENT(i))
3951 					continue;
3952 				cache = &z->uz_cpu[i];
3953 				if (cache->uc_allocbucket != NULL)
3954 					ups[i].ups_cache_free +=
3955 					    cache->uc_allocbucket->ub_cnt;
3956 				if (cache->uc_freebucket != NULL)
3957 					ups[i].ups_cache_free +=
3958 					    cache->uc_freebucket->ub_cnt;
3959 				ups[i].ups_allocs = cache->uc_allocs;
3960 				ups[i].ups_frees = cache->uc_frees;
3961 			}
3962 			ZONE_UNLOCK(z);
3963 			(void)sbuf_bcat(&sbuf, &uth, sizeof(uth));
3964 			for (i = 0; i < mp_maxid + 1; i++)
3965 				(void)sbuf_bcat(&sbuf, &ups[i], sizeof(ups[i]));
3966 		}
3967 	}
3968 	rw_runlock(&uma_rwlock);
3969 	error = sbuf_finish(&sbuf);
3970 	sbuf_delete(&sbuf);
3971 	free(ups, M_TEMP);
3972 	return (error);
3973 }
3974 
3975 int
3976 sysctl_handle_uma_zone_max(SYSCTL_HANDLER_ARGS)
3977 {
3978 	uma_zone_t zone = *(uma_zone_t *)arg1;
3979 	int error, max;
3980 
3981 	max = uma_zone_get_max(zone);
3982 	error = sysctl_handle_int(oidp, &max, 0, req);
3983 	if (error || !req->newptr)
3984 		return (error);
3985 
3986 	uma_zone_set_max(zone, max);
3987 
3988 	return (0);
3989 }
3990 
3991 int
3992 sysctl_handle_uma_zone_cur(SYSCTL_HANDLER_ARGS)
3993 {
3994 	uma_zone_t zone = *(uma_zone_t *)arg1;
3995 	int cur;
3996 
3997 	cur = uma_zone_get_cur(zone);
3998 	return (sysctl_handle_int(oidp, &cur, 0, req));
3999 }
4000 
4001 #ifdef INVARIANTS
4002 static uma_slab_t
4003 uma_dbg_getslab(uma_zone_t zone, void *item)
4004 {
4005 	uma_slab_t slab;
4006 	uma_keg_t keg;
4007 	uint8_t *mem;
4008 
4009 	mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
4010 	if (zone->uz_flags & UMA_ZONE_VTOSLAB) {
4011 		slab = vtoslab((vm_offset_t)mem);
4012 	} else {
4013 		/*
4014 		 * It is safe to return the slab here even though the
4015 		 * zone is unlocked because the item's allocation state
4016 		 * essentially holds a reference.
4017 		 */
4018 		if (zone->uz_lockptr == &zone->uz_lock)
4019 			return (NULL);
4020 		ZONE_LOCK(zone);
4021 		keg = zone->uz_keg;
4022 		if (keg->uk_flags & UMA_ZONE_HASH)
4023 			slab = hash_sfind(&keg->uk_hash, mem);
4024 		else
4025 			slab = (uma_slab_t)(mem + keg->uk_pgoff);
4026 		ZONE_UNLOCK(zone);
4027 	}
4028 
4029 	return (slab);
4030 }
4031 
4032 static bool
4033 uma_dbg_zskip(uma_zone_t zone, void *mem)
4034 {
4035 
4036 	if (zone->uz_lockptr == &zone->uz_lock)
4037 		return (true);
4038 
4039 	return (uma_dbg_kskip(zone->uz_keg, mem));
4040 }
4041 
4042 static bool
4043 uma_dbg_kskip(uma_keg_t keg, void *mem)
4044 {
4045 	uintptr_t idx;
4046 
4047 	if (dbg_divisor == 0)
4048 		return (true);
4049 
4050 	if (dbg_divisor == 1)
4051 		return (false);
4052 
4053 	idx = (uintptr_t)mem >> PAGE_SHIFT;
4054 	if (keg->uk_ipers > 1) {
4055 		idx *= keg->uk_ipers;
4056 		idx += ((uintptr_t)mem & PAGE_MASK) / keg->uk_rsize;
4057 	}
4058 
4059 	if ((idx / dbg_divisor) * dbg_divisor != idx) {
4060 		counter_u64_add(uma_skip_cnt, 1);
4061 		return (true);
4062 	}
4063 	counter_u64_add(uma_dbg_cnt, 1);
4064 
4065 	return (false);
4066 }
4067 
4068 /*
4069  * Set up the slab's freei data such that uma_dbg_free can function.
4070  *
4071  */
4072 static void
4073 uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item)
4074 {
4075 	uma_keg_t keg;
4076 	int freei;
4077 
4078 	if (slab == NULL) {
4079 		slab = uma_dbg_getslab(zone, item);
4080 		if (slab == NULL)
4081 			panic("uma: item %p did not belong to zone %s\n",
4082 			    item, zone->uz_name);
4083 	}
4084 	keg = slab->us_keg;
4085 	freei = ((uintptr_t)item - (uintptr_t)slab->us_data) / keg->uk_rsize;
4086 
4087 	if (BIT_ISSET(SLAB_SETSIZE, freei, &slab->us_debugfree))
4088 		panic("Duplicate alloc of %p from zone %p(%s) slab %p(%d)\n",
4089 		    item, zone, zone->uz_name, slab, freei);
4090 	BIT_SET_ATOMIC(SLAB_SETSIZE, freei, &slab->us_debugfree);
4091 
4092 	return;
4093 }
4094 
4095 /*
4096  * Verifies freed addresses.  Checks for alignment, valid slab membership
4097  * and duplicate frees.
4098  *
4099  */
4100 static void
4101 uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item)
4102 {
4103 	uma_keg_t keg;
4104 	int freei;
4105 
4106 	if (slab == NULL) {
4107 		slab = uma_dbg_getslab(zone, item);
4108 		if (slab == NULL)
4109 			panic("uma: Freed item %p did not belong to zone %s\n",
4110 			    item, zone->uz_name);
4111 	}
4112 	keg = slab->us_keg;
4113 	freei = ((uintptr_t)item - (uintptr_t)slab->us_data) / keg->uk_rsize;
4114 
4115 	if (freei >= keg->uk_ipers)
4116 		panic("Invalid free of %p from zone %p(%s) slab %p(%d)\n",
4117 		    item, zone, zone->uz_name, slab, freei);
4118 
4119 	if (((freei * keg->uk_rsize) + slab->us_data) != item)
4120 		panic("Unaligned free of %p from zone %p(%s) slab %p(%d)\n",
4121 		    item, zone, zone->uz_name, slab, freei);
4122 
4123 	if (!BIT_ISSET(SLAB_SETSIZE, freei, &slab->us_debugfree))
4124 		panic("Duplicate free of %p from zone %p(%s) slab %p(%d)\n",
4125 		    item, zone, zone->uz_name, slab, freei);
4126 
4127 	BIT_CLR_ATOMIC(SLAB_SETSIZE, freei, &slab->us_debugfree);
4128 }
4129 #endif /* INVARIANTS */
4130 
4131 #ifdef DDB
4132 DB_SHOW_COMMAND(uma, db_show_uma)
4133 {
4134 	uma_keg_t kz;
4135 	uma_zone_t z;
4136 	uint64_t allocs, frees, sleeps;
4137 	long cachefree;
4138 	int i;
4139 
4140 	db_printf("%18s %8s %8s %8s %12s %8s %8s\n", "Zone", "Size", "Used",
4141 	    "Free", "Requests", "Sleeps", "Bucket");
4142 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
4143 		LIST_FOREACH(z, &kz->uk_zones, uz_link) {
4144 			if (kz->uk_flags & UMA_ZFLAG_INTERNAL) {
4145 				allocs = counter_u64_fetch(z->uz_allocs);
4146 				frees = counter_u64_fetch(z->uz_frees);
4147 				sleeps = z->uz_sleeps;
4148 				cachefree = 0;
4149 			} else
4150 				uma_zone_sumstat(z, &cachefree, &allocs,
4151 				    &frees, &sleeps);
4152 			if (!((z->uz_flags & UMA_ZONE_SECONDARY) &&
4153 			    (LIST_FIRST(&kz->uk_zones) != z)))
4154 				cachefree += kz->uk_free;
4155 			for (i = 0; i < vm_ndomains; i++)
4156 				cachefree += z->uz_domain[i].uzd_nitems;
4157 
4158 			db_printf("%18s %8ju %8jd %8ld %12ju %8ju %8u\n",
4159 			    z->uz_name, (uintmax_t)kz->uk_size,
4160 			    (intmax_t)(allocs - frees), cachefree,
4161 			    (uintmax_t)allocs, sleeps, z->uz_count);
4162 			if (db_pager_quit)
4163 				return;
4164 		}
4165 	}
4166 }
4167 
4168 DB_SHOW_COMMAND(umacache, db_show_umacache)
4169 {
4170 	uma_zone_t z;
4171 	uint64_t allocs, frees;
4172 	long cachefree;
4173 	int i;
4174 
4175 	db_printf("%18s %8s %8s %8s %12s %8s\n", "Zone", "Size", "Used", "Free",
4176 	    "Requests", "Bucket");
4177 	LIST_FOREACH(z, &uma_cachezones, uz_link) {
4178 		uma_zone_sumstat(z, &cachefree, &allocs, &frees, NULL);
4179 		for (i = 0; i < vm_ndomains; i++)
4180 			cachefree += z->uz_domain[i].uzd_nitems;
4181 		db_printf("%18s %8ju %8jd %8ld %12ju %8u\n",
4182 		    z->uz_name, (uintmax_t)z->uz_size,
4183 		    (intmax_t)(allocs - frees), cachefree,
4184 		    (uintmax_t)allocs, z->uz_count);
4185 		if (db_pager_quit)
4186 			return;
4187 	}
4188 }
4189 #endif	/* DDB */
4190