xref: /freebsd/sys/vm/uma_core.c (revision b249ce48ea5560afdcff57e72a9880b7d3132434)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2002-2019 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 static MALLOC_DEFINE(M_UMA, "UMA", "UMA Misc");
123 
124 /*
125  * Are we allowed to allocate buckets?
126  */
127 static int bucketdisable = 1;
128 
129 /* Linked list of all kegs in the system */
130 static LIST_HEAD(,uma_keg) uma_kegs = LIST_HEAD_INITIALIZER(uma_kegs);
131 
132 /* Linked list of all cache-only zones in the system */
133 static LIST_HEAD(,uma_zone) uma_cachezones =
134     LIST_HEAD_INITIALIZER(uma_cachezones);
135 
136 /* This RW lock protects the keg list */
137 static struct rwlock_padalign __exclusive_cache_line uma_rwlock;
138 
139 /*
140  * Pointer and counter to pool of pages, that is preallocated at
141  * startup to bootstrap UMA.
142  */
143 static char *bootmem;
144 static int boot_pages;
145 
146 static struct sx uma_reclaim_lock;
147 
148 /*
149  * kmem soft limit, initialized by uma_set_limit().  Ensure that early
150  * allocations don't trigger a wakeup of the reclaim thread.
151  */
152 unsigned long uma_kmem_limit = LONG_MAX;
153 SYSCTL_ULONG(_vm, OID_AUTO, uma_kmem_limit, CTLFLAG_RD, &uma_kmem_limit, 0,
154     "UMA kernel memory soft limit");
155 unsigned long uma_kmem_total;
156 SYSCTL_ULONG(_vm, OID_AUTO, uma_kmem_total, CTLFLAG_RD, &uma_kmem_total, 0,
157     "UMA kernel memory usage");
158 
159 /* Is the VM done starting up? */
160 static enum { BOOT_COLD = 0, BOOT_STRAPPED, BOOT_PAGEALLOC, BOOT_BUCKETS,
161     BOOT_RUNNING } booted = BOOT_COLD;
162 
163 /*
164  * This is the handle used to schedule events that need to happen
165  * outside of the allocation fast path.
166  */
167 static struct callout uma_callout;
168 #define	UMA_TIMEOUT	20		/* Seconds for callout interval. */
169 
170 /*
171  * This structure is passed as the zone ctor arg so that I don't have to create
172  * a special allocation function just for zones.
173  */
174 struct uma_zctor_args {
175 	const char *name;
176 	size_t size;
177 	uma_ctor ctor;
178 	uma_dtor dtor;
179 	uma_init uminit;
180 	uma_fini fini;
181 	uma_import import;
182 	uma_release release;
183 	void *arg;
184 	uma_keg_t keg;
185 	int align;
186 	uint32_t flags;
187 };
188 
189 struct uma_kctor_args {
190 	uma_zone_t zone;
191 	size_t size;
192 	uma_init uminit;
193 	uma_fini fini;
194 	int align;
195 	uint32_t flags;
196 };
197 
198 struct uma_bucket_zone {
199 	uma_zone_t	ubz_zone;
200 	char		*ubz_name;
201 	int		ubz_entries;	/* Number of items it can hold. */
202 	int		ubz_maxsize;	/* Maximum allocation size per-item. */
203 };
204 
205 /*
206  * Compute the actual number of bucket entries to pack them in power
207  * of two sizes for more efficient space utilization.
208  */
209 #define	BUCKET_SIZE(n)						\
210     (((sizeof(void *) * (n)) - sizeof(struct uma_bucket)) / sizeof(void *))
211 
212 #define	BUCKET_MAX	BUCKET_SIZE(256)
213 #define	BUCKET_MIN	BUCKET_SIZE(4)
214 
215 struct uma_bucket_zone bucket_zones[] = {
216 	{ NULL, "4 Bucket", BUCKET_SIZE(4), 4096 },
217 	{ NULL, "6 Bucket", BUCKET_SIZE(6), 3072 },
218 	{ NULL, "8 Bucket", BUCKET_SIZE(8), 2048 },
219 	{ NULL, "12 Bucket", BUCKET_SIZE(12), 1536 },
220 	{ NULL, "16 Bucket", BUCKET_SIZE(16), 1024 },
221 	{ NULL, "32 Bucket", BUCKET_SIZE(32), 512 },
222 	{ NULL, "64 Bucket", BUCKET_SIZE(64), 256 },
223 	{ NULL, "128 Bucket", BUCKET_SIZE(128), 128 },
224 	{ NULL, "256 Bucket", BUCKET_SIZE(256), 64 },
225 	{ NULL, NULL, 0}
226 };
227 
228 /*
229  * Flags and enumerations to be passed to internal functions.
230  */
231 enum zfreeskip {
232 	SKIP_NONE =	0,
233 	SKIP_CNT =	0x00000001,
234 	SKIP_DTOR =	0x00010000,
235 	SKIP_FINI =	0x00020000,
236 };
237 
238 /* Prototypes.. */
239 
240 int	uma_startup_count(int);
241 void	uma_startup(void *, int);
242 void	uma_startup1(void);
243 void	uma_startup2(void);
244 
245 static void *noobj_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
246 static void *page_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
247 static void *pcpu_page_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
248 static void *startup_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
249 static void page_free(void *, vm_size_t, uint8_t);
250 static void pcpu_page_free(void *, vm_size_t, uint8_t);
251 static uma_slab_t keg_alloc_slab(uma_keg_t, uma_zone_t, int, int, int);
252 static void cache_drain(uma_zone_t);
253 static void bucket_drain(uma_zone_t, uma_bucket_t);
254 static void bucket_cache_reclaim(uma_zone_t zone, bool);
255 static int keg_ctor(void *, int, void *, int);
256 static void keg_dtor(void *, int, void *);
257 static int zone_ctor(void *, int, void *, int);
258 static void zone_dtor(void *, int, void *);
259 static int zero_init(void *, int, int);
260 static void keg_small_init(uma_keg_t keg);
261 static void keg_large_init(uma_keg_t keg);
262 static void zone_foreach(void (*zfunc)(uma_zone_t, void *), void *);
263 static void zone_timeout(uma_zone_t zone, void *);
264 static int hash_alloc(struct uma_hash *, u_int);
265 static int hash_expand(struct uma_hash *, struct uma_hash *);
266 static void hash_free(struct uma_hash *hash);
267 static void uma_timeout(void *);
268 static void uma_startup3(void);
269 static void *zone_alloc_item(uma_zone_t, void *, int, int);
270 static void *zone_alloc_item_locked(uma_zone_t, void *, int, int);
271 static void zone_free_item(uma_zone_t, void *, void *, enum zfreeskip);
272 static void bucket_enable(void);
273 static void bucket_init(void);
274 static uma_bucket_t bucket_alloc(uma_zone_t zone, void *, int);
275 static void bucket_free(uma_zone_t zone, uma_bucket_t, void *);
276 static void bucket_zone_drain(void);
277 static uma_bucket_t zone_alloc_bucket(uma_zone_t, void *, int, int);
278 static void *slab_alloc_item(uma_keg_t keg, uma_slab_t slab);
279 static void slab_free_item(uma_zone_t zone, uma_slab_t slab, void *item);
280 static uma_keg_t uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit,
281     uma_fini fini, int align, uint32_t flags);
282 static int zone_import(void *, void **, int, int, int);
283 static void zone_release(void *, void **, int);
284 static bool cache_alloc(uma_zone_t, uma_cache_t, void *, int);
285 static bool cache_free(uma_zone_t, uma_cache_t, void *, void *, int);
286 
287 static int sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS);
288 static int sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS);
289 static int sysctl_handle_uma_zone_allocs(SYSCTL_HANDLER_ARGS);
290 static int sysctl_handle_uma_zone_frees(SYSCTL_HANDLER_ARGS);
291 static int sysctl_handle_uma_zone_flags(SYSCTL_HANDLER_ARGS);
292 static int sysctl_handle_uma_slab_efficiency(SYSCTL_HANDLER_ARGS);
293 
294 #ifdef INVARIANTS
295 static inline struct noslabbits *slab_dbg_bits(uma_slab_t slab, uma_keg_t keg);
296 
297 static bool uma_dbg_kskip(uma_keg_t keg, void *mem);
298 static bool uma_dbg_zskip(uma_zone_t zone, void *mem);
299 static void uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item);
300 static void uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item);
301 
302 static SYSCTL_NODE(_vm, OID_AUTO, debug, CTLFLAG_RD, 0,
303     "Memory allocation debugging");
304 
305 static u_int dbg_divisor = 1;
306 SYSCTL_UINT(_vm_debug, OID_AUTO, divisor,
307     CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &dbg_divisor, 0,
308     "Debug & thrash every this item in memory allocator");
309 
310 static counter_u64_t uma_dbg_cnt = EARLY_COUNTER;
311 static counter_u64_t uma_skip_cnt = EARLY_COUNTER;
312 SYSCTL_COUNTER_U64(_vm_debug, OID_AUTO, trashed, CTLFLAG_RD,
313     &uma_dbg_cnt, "memory items debugged");
314 SYSCTL_COUNTER_U64(_vm_debug, OID_AUTO, skipped, CTLFLAG_RD,
315     &uma_skip_cnt, "memory items skipped, not debugged");
316 #endif
317 
318 SYSINIT(uma_startup3, SI_SUB_VM_CONF, SI_ORDER_SECOND, uma_startup3, NULL);
319 
320 SYSCTL_NODE(_vm, OID_AUTO, uma, CTLFLAG_RW, 0, "Universal Memory Allocator");
321 
322 SYSCTL_PROC(_vm, OID_AUTO, zone_count, CTLFLAG_RD|CTLTYPE_INT,
323     0, 0, sysctl_vm_zone_count, "I", "Number of UMA zones");
324 
325 SYSCTL_PROC(_vm, OID_AUTO, zone_stats, CTLFLAG_RD|CTLTYPE_STRUCT,
326     0, 0, sysctl_vm_zone_stats, "s,struct uma_type_header", "Zone Stats");
327 
328 static int zone_warnings = 1;
329 SYSCTL_INT(_vm, OID_AUTO, zone_warnings, CTLFLAG_RWTUN, &zone_warnings, 0,
330     "Warn when UMA zones becomes full");
331 
332 /*
333  * This routine checks to see whether or not it's safe to enable buckets.
334  */
335 static void
336 bucket_enable(void)
337 {
338 
339 	KASSERT(booted >= BOOT_BUCKETS, ("Bucket enable before init"));
340 	bucketdisable = vm_page_count_min();
341 }
342 
343 /*
344  * Initialize bucket_zones, the array of zones of buckets of various sizes.
345  *
346  * For each zone, calculate the memory required for each bucket, consisting
347  * of the header and an array of pointers.
348  */
349 static void
350 bucket_init(void)
351 {
352 	struct uma_bucket_zone *ubz;
353 	int size;
354 
355 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++) {
356 		size = roundup(sizeof(struct uma_bucket), sizeof(void *));
357 		size += sizeof(void *) * ubz->ubz_entries;
358 		ubz->ubz_zone = uma_zcreate(ubz->ubz_name, size,
359 		    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR,
360 		    UMA_ZONE_MTXCLASS | UMA_ZFLAG_BUCKET | UMA_ZONE_NUMA);
361 	}
362 }
363 
364 /*
365  * Given a desired number of entries for a bucket, return the zone from which
366  * to allocate the bucket.
367  */
368 static struct uma_bucket_zone *
369 bucket_zone_lookup(int entries)
370 {
371 	struct uma_bucket_zone *ubz;
372 
373 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
374 		if (ubz->ubz_entries >= entries)
375 			return (ubz);
376 	ubz--;
377 	return (ubz);
378 }
379 
380 static struct uma_bucket_zone *
381 bucket_zone_max(uma_zone_t zone, int nitems)
382 {
383 	struct uma_bucket_zone *ubz;
384 	int bpcpu;
385 
386 	bpcpu = 2;
387 #ifdef UMA_XDOMAIN
388 	if ((zone->uz_flags & UMA_ZONE_NUMA) != 0)
389 		/* Count the cross-domain bucket. */
390 		bpcpu++;
391 #endif
392 
393 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
394 		if (ubz->ubz_entries * bpcpu * mp_ncpus > nitems)
395 			break;
396 	if (ubz == &bucket_zones[0])
397 		ubz = NULL;
398 	else
399 		ubz--;
400 	return (ubz);
401 }
402 
403 static int
404 bucket_select(int size)
405 {
406 	struct uma_bucket_zone *ubz;
407 
408 	ubz = &bucket_zones[0];
409 	if (size > ubz->ubz_maxsize)
410 		return MAX((ubz->ubz_maxsize * ubz->ubz_entries) / size, 1);
411 
412 	for (; ubz->ubz_entries != 0; ubz++)
413 		if (ubz->ubz_maxsize < size)
414 			break;
415 	ubz--;
416 	return (ubz->ubz_entries);
417 }
418 
419 static uma_bucket_t
420 bucket_alloc(uma_zone_t zone, void *udata, int flags)
421 {
422 	struct uma_bucket_zone *ubz;
423 	uma_bucket_t bucket;
424 
425 	/*
426 	 * This is to stop us from allocating per cpu buckets while we're
427 	 * running out of vm.boot_pages.  Otherwise, we would exhaust the
428 	 * boot pages.  This also prevents us from allocating buckets in
429 	 * low memory situations.
430 	 */
431 	if (bucketdisable)
432 		return (NULL);
433 	/*
434 	 * To limit bucket recursion we store the original zone flags
435 	 * in a cookie passed via zalloc_arg/zfree_arg.  This allows the
436 	 * NOVM flag to persist even through deep recursions.  We also
437 	 * store ZFLAG_BUCKET once we have recursed attempting to allocate
438 	 * a bucket for a bucket zone so we do not allow infinite bucket
439 	 * recursion.  This cookie will even persist to frees of unused
440 	 * buckets via the allocation path or bucket allocations in the
441 	 * free path.
442 	 */
443 	if ((zone->uz_flags & UMA_ZFLAG_BUCKET) == 0)
444 		udata = (void *)(uintptr_t)zone->uz_flags;
445 	else {
446 		if ((uintptr_t)udata & UMA_ZFLAG_BUCKET)
447 			return (NULL);
448 		udata = (void *)((uintptr_t)udata | UMA_ZFLAG_BUCKET);
449 	}
450 	if ((uintptr_t)udata & UMA_ZFLAG_CACHEONLY)
451 		flags |= M_NOVM;
452 	ubz = bucket_zone_lookup(zone->uz_bucket_size);
453 	if (ubz->ubz_zone == zone && (ubz + 1)->ubz_entries != 0)
454 		ubz++;
455 	bucket = uma_zalloc_arg(ubz->ubz_zone, udata, flags);
456 	if (bucket) {
457 #ifdef INVARIANTS
458 		bzero(bucket->ub_bucket, sizeof(void *) * ubz->ubz_entries);
459 #endif
460 		bucket->ub_cnt = 0;
461 		bucket->ub_entries = ubz->ubz_entries;
462 	}
463 
464 	return (bucket);
465 }
466 
467 static void
468 bucket_free(uma_zone_t zone, uma_bucket_t bucket, void *udata)
469 {
470 	struct uma_bucket_zone *ubz;
471 
472 	KASSERT(bucket->ub_cnt == 0,
473 	    ("bucket_free: Freeing a non free bucket."));
474 	if ((zone->uz_flags & UMA_ZFLAG_BUCKET) == 0)
475 		udata = (void *)(uintptr_t)zone->uz_flags;
476 	ubz = bucket_zone_lookup(bucket->ub_entries);
477 	uma_zfree_arg(ubz->ubz_zone, bucket, udata);
478 }
479 
480 static void
481 bucket_zone_drain(void)
482 {
483 	struct uma_bucket_zone *ubz;
484 
485 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
486 		uma_zone_reclaim(ubz->ubz_zone, UMA_RECLAIM_DRAIN);
487 }
488 
489 /*
490  * Attempt to satisfy an allocation by retrieving a full bucket from one of the
491  * zone's caches.
492  */
493 static uma_bucket_t
494 zone_fetch_bucket(uma_zone_t zone, uma_zone_domain_t zdom)
495 {
496 	uma_bucket_t bucket;
497 
498 	ZONE_LOCK_ASSERT(zone);
499 
500 	if ((bucket = TAILQ_FIRST(&zdom->uzd_buckets)) != NULL) {
501 		MPASS(zdom->uzd_nitems >= bucket->ub_cnt);
502 		TAILQ_REMOVE(&zdom->uzd_buckets, bucket, ub_link);
503 		zdom->uzd_nitems -= bucket->ub_cnt;
504 		if (zdom->uzd_imin > zdom->uzd_nitems)
505 			zdom->uzd_imin = zdom->uzd_nitems;
506 		zone->uz_bkt_count -= bucket->ub_cnt;
507 	}
508 	return (bucket);
509 }
510 
511 /*
512  * Insert a full bucket into the specified cache.  The "ws" parameter indicates
513  * whether the bucket's contents should be counted as part of the zone's working
514  * set.
515  */
516 static void
517 zone_put_bucket(uma_zone_t zone, uma_zone_domain_t zdom, uma_bucket_t bucket,
518     const bool ws)
519 {
520 
521 	ZONE_LOCK_ASSERT(zone);
522 	KASSERT(!ws || zone->uz_bkt_count < zone->uz_bkt_max,
523 	    ("%s: zone %p overflow", __func__, zone));
524 
525 	if (ws)
526 		TAILQ_INSERT_HEAD(&zdom->uzd_buckets, bucket, ub_link);
527 	else
528 		TAILQ_INSERT_TAIL(&zdom->uzd_buckets, bucket, ub_link);
529 	zdom->uzd_nitems += bucket->ub_cnt;
530 	if (ws && zdom->uzd_imax < zdom->uzd_nitems)
531 		zdom->uzd_imax = zdom->uzd_nitems;
532 	zone->uz_bkt_count += bucket->ub_cnt;
533 }
534 
535 /* Pops an item out of a per-cpu cache bucket. */
536 static inline void *
537 cache_bucket_pop(uma_cache_t cache, uma_cache_bucket_t bucket)
538 {
539 	void *item;
540 
541 	CRITICAL_ASSERT(curthread);
542 
543 	bucket->ucb_cnt--;
544 	item = bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt];
545 #ifdef INVARIANTS
546 	bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt] = NULL;
547 	KASSERT(item != NULL, ("uma_zalloc: Bucket pointer mangled."));
548 #endif
549 	cache->uc_allocs++;
550 
551 	return (item);
552 }
553 
554 /* Pushes an item into a per-cpu cache bucket. */
555 static inline void
556 cache_bucket_push(uma_cache_t cache, uma_cache_bucket_t bucket, void *item)
557 {
558 
559 	CRITICAL_ASSERT(curthread);
560 	KASSERT(bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt] == NULL,
561 	    ("uma_zfree: Freeing to non free bucket index."));
562 
563 	bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt] = item;
564 	bucket->ucb_cnt++;
565 	cache->uc_frees++;
566 }
567 
568 /*
569  * Unload a UMA bucket from a per-cpu cache.
570  */
571 static inline uma_bucket_t
572 cache_bucket_unload(uma_cache_bucket_t bucket)
573 {
574 	uma_bucket_t b;
575 
576 	b = bucket->ucb_bucket;
577 	if (b != NULL) {
578 		MPASS(b->ub_entries == bucket->ucb_entries);
579 		b->ub_cnt = bucket->ucb_cnt;
580 		bucket->ucb_bucket = NULL;
581 		bucket->ucb_entries = bucket->ucb_cnt = 0;
582 	}
583 
584 	return (b);
585 }
586 
587 static inline uma_bucket_t
588 cache_bucket_unload_alloc(uma_cache_t cache)
589 {
590 
591 	return (cache_bucket_unload(&cache->uc_allocbucket));
592 }
593 
594 static inline uma_bucket_t
595 cache_bucket_unload_free(uma_cache_t cache)
596 {
597 
598 	return (cache_bucket_unload(&cache->uc_freebucket));
599 }
600 
601 static inline uma_bucket_t
602 cache_bucket_unload_cross(uma_cache_t cache)
603 {
604 
605 	return (cache_bucket_unload(&cache->uc_crossbucket));
606 }
607 
608 /*
609  * Load a bucket into a per-cpu cache bucket.
610  */
611 static inline void
612 cache_bucket_load(uma_cache_bucket_t bucket, uma_bucket_t b)
613 {
614 
615 	CRITICAL_ASSERT(curthread);
616 	MPASS(bucket->ucb_bucket == NULL);
617 
618 	bucket->ucb_bucket = b;
619 	bucket->ucb_cnt = b->ub_cnt;
620 	bucket->ucb_entries = b->ub_entries;
621 }
622 
623 static inline void
624 cache_bucket_load_alloc(uma_cache_t cache, uma_bucket_t b)
625 {
626 
627 	cache_bucket_load(&cache->uc_allocbucket, b);
628 }
629 
630 static inline void
631 cache_bucket_load_free(uma_cache_t cache, uma_bucket_t b)
632 {
633 
634 	cache_bucket_load(&cache->uc_freebucket, b);
635 }
636 
637 #ifdef UMA_XDOMAIN
638 static inline void
639 cache_bucket_load_cross(uma_cache_t cache, uma_bucket_t b)
640 {
641 
642 	cache_bucket_load(&cache->uc_crossbucket, b);
643 }
644 #endif
645 
646 /*
647  * Copy and preserve ucb_spare.
648  */
649 static inline void
650 cache_bucket_copy(uma_cache_bucket_t b1, uma_cache_bucket_t b2)
651 {
652 
653 	b1->ucb_bucket = b2->ucb_bucket;
654 	b1->ucb_entries = b2->ucb_entries;
655 	b1->ucb_cnt = b2->ucb_cnt;
656 }
657 
658 /*
659  * Swap two cache buckets.
660  */
661 static inline void
662 cache_bucket_swap(uma_cache_bucket_t b1, uma_cache_bucket_t b2)
663 {
664 	struct uma_cache_bucket b3;
665 
666 	CRITICAL_ASSERT(curthread);
667 
668 	cache_bucket_copy(&b3, b1);
669 	cache_bucket_copy(b1, b2);
670 	cache_bucket_copy(b2, &b3);
671 }
672 
673 static void
674 zone_log_warning(uma_zone_t zone)
675 {
676 	static const struct timeval warninterval = { 300, 0 };
677 
678 	if (!zone_warnings || zone->uz_warning == NULL)
679 		return;
680 
681 	if (ratecheck(&zone->uz_ratecheck, &warninterval))
682 		printf("[zone: %s] %s\n", zone->uz_name, zone->uz_warning);
683 }
684 
685 static inline void
686 zone_maxaction(uma_zone_t zone)
687 {
688 
689 	if (zone->uz_maxaction.ta_func != NULL)
690 		taskqueue_enqueue(taskqueue_thread, &zone->uz_maxaction);
691 }
692 
693 /*
694  * Routine called by timeout which is used to fire off some time interval
695  * based calculations.  (stats, hash size, etc.)
696  *
697  * Arguments:
698  *	arg   Unused
699  *
700  * Returns:
701  *	Nothing
702  */
703 static void
704 uma_timeout(void *unused)
705 {
706 	bucket_enable();
707 	zone_foreach(zone_timeout, NULL);
708 
709 	/* Reschedule this event */
710 	callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
711 }
712 
713 /*
714  * Update the working set size estimate for the zone's bucket cache.
715  * The constants chosen here are somewhat arbitrary.  With an update period of
716  * 20s (UMA_TIMEOUT), this estimate is dominated by zone activity over the
717  * last 100s.
718  */
719 static void
720 zone_domain_update_wss(uma_zone_domain_t zdom)
721 {
722 	long wss;
723 
724 	MPASS(zdom->uzd_imax >= zdom->uzd_imin);
725 	wss = zdom->uzd_imax - zdom->uzd_imin;
726 	zdom->uzd_imax = zdom->uzd_imin = zdom->uzd_nitems;
727 	zdom->uzd_wss = (4 * wss + zdom->uzd_wss) / 5;
728 }
729 
730 /*
731  * Routine to perform timeout driven calculations.  This expands the
732  * hashes and does per cpu statistics aggregation.
733  *
734  *  Returns nothing.
735  */
736 static void
737 zone_timeout(uma_zone_t zone, void *unused)
738 {
739 	uma_keg_t keg;
740 	u_int slabs;
741 
742 	if ((zone->uz_flags & UMA_ZONE_HASH) == 0)
743 		goto update_wss;
744 
745 	keg = zone->uz_keg;
746 	KEG_LOCK(keg);
747 	/*
748 	 * Expand the keg hash table.
749 	 *
750 	 * This is done if the number of slabs is larger than the hash size.
751 	 * What I'm trying to do here is completely reduce collisions.  This
752 	 * may be a little aggressive.  Should I allow for two collisions max?
753 	 */
754 	if (keg->uk_flags & UMA_ZONE_HASH &&
755 	    (slabs = keg->uk_pages / keg->uk_ppera) >
756 	     keg->uk_hash.uh_hashsize) {
757 		struct uma_hash newhash;
758 		struct uma_hash oldhash;
759 		int ret;
760 
761 		/*
762 		 * This is so involved because allocating and freeing
763 		 * while the keg lock is held will lead to deadlock.
764 		 * I have to do everything in stages and check for
765 		 * races.
766 		 */
767 		KEG_UNLOCK(keg);
768 		ret = hash_alloc(&newhash, 1 << fls(slabs));
769 		KEG_LOCK(keg);
770 		if (ret) {
771 			if (hash_expand(&keg->uk_hash, &newhash)) {
772 				oldhash = keg->uk_hash;
773 				keg->uk_hash = newhash;
774 			} else
775 				oldhash = newhash;
776 
777 			KEG_UNLOCK(keg);
778 			hash_free(&oldhash);
779 			return;
780 		}
781 	}
782 	KEG_UNLOCK(keg);
783 
784 update_wss:
785 	ZONE_LOCK(zone);
786 	for (int i = 0; i < vm_ndomains; i++)
787 		zone_domain_update_wss(&zone->uz_domain[i]);
788 	ZONE_UNLOCK(zone);
789 }
790 
791 /*
792  * Allocate and zero fill the next sized hash table from the appropriate
793  * backing store.
794  *
795  * Arguments:
796  *	hash  A new hash structure with the old hash size in uh_hashsize
797  *
798  * Returns:
799  *	1 on success and 0 on failure.
800  */
801 static int
802 hash_alloc(struct uma_hash *hash, u_int size)
803 {
804 	size_t alloc;
805 
806 	KASSERT(powerof2(size), ("hash size must be power of 2"));
807 	if (size > UMA_HASH_SIZE_INIT)  {
808 		hash->uh_hashsize = size;
809 		alloc = sizeof(hash->uh_slab_hash[0]) * hash->uh_hashsize;
810 		hash->uh_slab_hash = malloc(alloc, M_UMAHASH, M_NOWAIT);
811 	} else {
812 		alloc = sizeof(hash->uh_slab_hash[0]) * UMA_HASH_SIZE_INIT;
813 		hash->uh_slab_hash = zone_alloc_item(hashzone, NULL,
814 		    UMA_ANYDOMAIN, M_WAITOK);
815 		hash->uh_hashsize = UMA_HASH_SIZE_INIT;
816 	}
817 	if (hash->uh_slab_hash) {
818 		bzero(hash->uh_slab_hash, alloc);
819 		hash->uh_hashmask = hash->uh_hashsize - 1;
820 		return (1);
821 	}
822 
823 	return (0);
824 }
825 
826 /*
827  * Expands the hash table for HASH zones.  This is done from zone_timeout
828  * to reduce collisions.  This must not be done in the regular allocation
829  * path, otherwise, we can recurse on the vm while allocating pages.
830  *
831  * Arguments:
832  *	oldhash  The hash you want to expand
833  *	newhash  The hash structure for the new table
834  *
835  * Returns:
836  *	Nothing
837  *
838  * Discussion:
839  */
840 static int
841 hash_expand(struct uma_hash *oldhash, struct uma_hash *newhash)
842 {
843 	uma_hash_slab_t slab;
844 	u_int hval;
845 	u_int idx;
846 
847 	if (!newhash->uh_slab_hash)
848 		return (0);
849 
850 	if (oldhash->uh_hashsize >= newhash->uh_hashsize)
851 		return (0);
852 
853 	/*
854 	 * I need to investigate hash algorithms for resizing without a
855 	 * full rehash.
856 	 */
857 
858 	for (idx = 0; idx < oldhash->uh_hashsize; idx++)
859 		while (!LIST_EMPTY(&oldhash->uh_slab_hash[idx])) {
860 			slab = LIST_FIRST(&oldhash->uh_slab_hash[idx]);
861 			LIST_REMOVE(slab, uhs_hlink);
862 			hval = UMA_HASH(newhash, slab->uhs_data);
863 			LIST_INSERT_HEAD(&newhash->uh_slab_hash[hval],
864 			    slab, uhs_hlink);
865 		}
866 
867 	return (1);
868 }
869 
870 /*
871  * Free the hash bucket to the appropriate backing store.
872  *
873  * Arguments:
874  *	slab_hash  The hash bucket we're freeing
875  *	hashsize   The number of entries in that hash bucket
876  *
877  * Returns:
878  *	Nothing
879  */
880 static void
881 hash_free(struct uma_hash *hash)
882 {
883 	if (hash->uh_slab_hash == NULL)
884 		return;
885 	if (hash->uh_hashsize == UMA_HASH_SIZE_INIT)
886 		zone_free_item(hashzone, hash->uh_slab_hash, NULL, SKIP_NONE);
887 	else
888 		free(hash->uh_slab_hash, M_UMAHASH);
889 }
890 
891 /*
892  * Frees all outstanding items in a bucket
893  *
894  * Arguments:
895  *	zone   The zone to free to, must be unlocked.
896  *	bucket The free/alloc bucket with items, cpu queue must be locked.
897  *
898  * Returns:
899  *	Nothing
900  */
901 
902 static void
903 bucket_drain(uma_zone_t zone, uma_bucket_t bucket)
904 {
905 	int i;
906 
907 	if (bucket == NULL)
908 		return;
909 
910 	if (zone->uz_fini)
911 		for (i = 0; i < bucket->ub_cnt; i++)
912 			zone->uz_fini(bucket->ub_bucket[i], zone->uz_size);
913 	zone->uz_release(zone->uz_arg, bucket->ub_bucket, bucket->ub_cnt);
914 	if (zone->uz_max_items > 0) {
915 		ZONE_LOCK(zone);
916 		zone->uz_items -= bucket->ub_cnt;
917 		if (zone->uz_sleepers && zone->uz_items < zone->uz_max_items)
918 			wakeup_one(zone);
919 		ZONE_UNLOCK(zone);
920 	}
921 	bucket->ub_cnt = 0;
922 }
923 
924 /*
925  * Drains the per cpu caches for a zone.
926  *
927  * NOTE: This may only be called while the zone is being turn down, and not
928  * during normal operation.  This is necessary in order that we do not have
929  * to migrate CPUs to drain the per-CPU caches.
930  *
931  * Arguments:
932  *	zone     The zone to drain, must be unlocked.
933  *
934  * Returns:
935  *	Nothing
936  */
937 static void
938 cache_drain(uma_zone_t zone)
939 {
940 	uma_cache_t cache;
941 	uma_bucket_t bucket;
942 	int cpu;
943 
944 	/*
945 	 * XXX: It is safe to not lock the per-CPU caches, because we're
946 	 * tearing down the zone anyway.  I.e., there will be no further use
947 	 * of the caches at this point.
948 	 *
949 	 * XXX: It would good to be able to assert that the zone is being
950 	 * torn down to prevent improper use of cache_drain().
951 	 *
952 	 * XXX: We lock the zone before passing into bucket_cache_reclaim() as
953 	 * it is used elsewhere.  Should the tear-down path be made special
954 	 * there in some form?
955 	 */
956 	CPU_FOREACH(cpu) {
957 		cache = &zone->uz_cpu[cpu];
958 		bucket = cache_bucket_unload_alloc(cache);
959 		if (bucket != NULL) {
960 			bucket_drain(zone, bucket);
961 			bucket_free(zone, bucket, NULL);
962 		}
963 		bucket = cache_bucket_unload_free(cache);
964 		if (bucket != NULL) {
965 			bucket_drain(zone, bucket);
966 			bucket_free(zone, bucket, NULL);
967 		}
968 		bucket = cache_bucket_unload_cross(cache);
969 		if (bucket != NULL) {
970 			bucket_drain(zone, bucket);
971 			bucket_free(zone, bucket, NULL);
972 		}
973 	}
974 	ZONE_LOCK(zone);
975 	bucket_cache_reclaim(zone, true);
976 	ZONE_UNLOCK(zone);
977 }
978 
979 static void
980 cache_shrink(uma_zone_t zone, void *unused)
981 {
982 
983 	if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
984 		return;
985 
986 	ZONE_LOCK(zone);
987 	zone->uz_bucket_size =
988 	    (zone->uz_bucket_size_min + zone->uz_bucket_size) / 2;
989 	ZONE_UNLOCK(zone);
990 }
991 
992 static void
993 cache_drain_safe_cpu(uma_zone_t zone, void *unused)
994 {
995 	uma_cache_t cache;
996 	uma_bucket_t b1, b2, b3;
997 	int domain;
998 
999 	if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
1000 		return;
1001 
1002 	b1 = b2 = b3 = NULL;
1003 	ZONE_LOCK(zone);
1004 	critical_enter();
1005 	if (zone->uz_flags & UMA_ZONE_NUMA)
1006 		domain = PCPU_GET(domain);
1007 	else
1008 		domain = 0;
1009 	cache = &zone->uz_cpu[curcpu];
1010 	b1 = cache_bucket_unload_alloc(cache);
1011 	if (b1 != NULL && b1->ub_cnt != 0) {
1012 		zone_put_bucket(zone, &zone->uz_domain[domain], b1, false);
1013 		b1 = NULL;
1014 	}
1015 	b2 = cache_bucket_unload_free(cache);
1016 	if (b2 != NULL && b2->ub_cnt != 0) {
1017 		zone_put_bucket(zone, &zone->uz_domain[domain], b2, false);
1018 		b2 = NULL;
1019 	}
1020 	b3 = cache_bucket_unload_cross(cache);
1021 	critical_exit();
1022 	ZONE_UNLOCK(zone);
1023 	if (b1)
1024 		bucket_free(zone, b1, NULL);
1025 	if (b2)
1026 		bucket_free(zone, b2, NULL);
1027 	if (b3) {
1028 		bucket_drain(zone, b3);
1029 		bucket_free(zone, b3, NULL);
1030 	}
1031 }
1032 
1033 /*
1034  * Safely drain per-CPU caches of a zone(s) to alloc bucket.
1035  * This is an expensive call because it needs to bind to all CPUs
1036  * one by one and enter a critical section on each of them in order
1037  * to safely access their cache buckets.
1038  * Zone lock must not be held on call this function.
1039  */
1040 static void
1041 pcpu_cache_drain_safe(uma_zone_t zone)
1042 {
1043 	int cpu;
1044 
1045 	/*
1046 	 * Polite bucket sizes shrinking was not enouth, shrink aggressively.
1047 	 */
1048 	if (zone)
1049 		cache_shrink(zone, NULL);
1050 	else
1051 		zone_foreach(cache_shrink, NULL);
1052 
1053 	CPU_FOREACH(cpu) {
1054 		thread_lock(curthread);
1055 		sched_bind(curthread, cpu);
1056 		thread_unlock(curthread);
1057 
1058 		if (zone)
1059 			cache_drain_safe_cpu(zone, NULL);
1060 		else
1061 			zone_foreach(cache_drain_safe_cpu, NULL);
1062 	}
1063 	thread_lock(curthread);
1064 	sched_unbind(curthread);
1065 	thread_unlock(curthread);
1066 }
1067 
1068 /*
1069  * Reclaim cached buckets from a zone.  All buckets are reclaimed if the caller
1070  * requested a drain, otherwise the per-domain caches are trimmed to either
1071  * estimated working set size.
1072  */
1073 static void
1074 bucket_cache_reclaim(uma_zone_t zone, bool drain)
1075 {
1076 	uma_zone_domain_t zdom;
1077 	uma_bucket_t bucket;
1078 	long target, tofree;
1079 	int i;
1080 
1081 	for (i = 0; i < vm_ndomains; i++) {
1082 		zdom = &zone->uz_domain[i];
1083 
1084 		/*
1085 		 * If we were asked to drain the zone, we are done only once
1086 		 * this bucket cache is empty.  Otherwise, we reclaim items in
1087 		 * excess of the zone's estimated working set size.  If the
1088 		 * difference nitems - imin is larger than the WSS estimate,
1089 		 * then the estimate will grow at the end of this interval and
1090 		 * we ignore the historical average.
1091 		 */
1092 		target = drain ? 0 : lmax(zdom->uzd_wss, zdom->uzd_nitems -
1093 		    zdom->uzd_imin);
1094 		while (zdom->uzd_nitems > target) {
1095 			bucket = TAILQ_LAST(&zdom->uzd_buckets, uma_bucketlist);
1096 			if (bucket == NULL)
1097 				break;
1098 			tofree = bucket->ub_cnt;
1099 			TAILQ_REMOVE(&zdom->uzd_buckets, bucket, ub_link);
1100 			zdom->uzd_nitems -= tofree;
1101 
1102 			/*
1103 			 * Shift the bounds of the current WSS interval to avoid
1104 			 * perturbing the estimate.
1105 			 */
1106 			zdom->uzd_imax -= lmin(zdom->uzd_imax, tofree);
1107 			zdom->uzd_imin -= lmin(zdom->uzd_imin, tofree);
1108 
1109 			ZONE_UNLOCK(zone);
1110 			bucket_drain(zone, bucket);
1111 			bucket_free(zone, bucket, NULL);
1112 			ZONE_LOCK(zone);
1113 		}
1114 	}
1115 
1116 	/*
1117 	 * Shrink the zone bucket size to ensure that the per-CPU caches
1118 	 * don't grow too large.
1119 	 */
1120 	if (zone->uz_bucket_size > zone->uz_bucket_size_min)
1121 		zone->uz_bucket_size--;
1122 }
1123 
1124 static void
1125 keg_free_slab(uma_keg_t keg, uma_slab_t slab, int start)
1126 {
1127 	uint8_t *mem;
1128 	int i;
1129 	uint8_t flags;
1130 
1131 	CTR4(KTR_UMA, "keg_free_slab keg %s(%p) slab %p, returning %d bytes",
1132 	    keg->uk_name, keg, slab, PAGE_SIZE * keg->uk_ppera);
1133 
1134 	mem = slab_data(slab, keg);
1135 	flags = slab->us_flags;
1136 	i = start;
1137 	if (keg->uk_fini != NULL) {
1138 		for (i--; i > -1; i--)
1139 #ifdef INVARIANTS
1140 		/*
1141 		 * trash_fini implies that dtor was trash_dtor. trash_fini
1142 		 * would check that memory hasn't been modified since free,
1143 		 * which executed trash_dtor.
1144 		 * That's why we need to run uma_dbg_kskip() check here,
1145 		 * albeit we don't make skip check for other init/fini
1146 		 * invocations.
1147 		 */
1148 		if (!uma_dbg_kskip(keg, slab_item(slab, keg, i)) ||
1149 		    keg->uk_fini != trash_fini)
1150 #endif
1151 			keg->uk_fini(slab_item(slab, keg, i), keg->uk_size);
1152 	}
1153 	if (keg->uk_flags & UMA_ZONE_OFFPAGE)
1154 		zone_free_item(keg->uk_slabzone, slab, NULL, SKIP_NONE);
1155 	keg->uk_freef(mem, PAGE_SIZE * keg->uk_ppera, flags);
1156 	uma_total_dec(PAGE_SIZE * keg->uk_ppera);
1157 }
1158 
1159 /*
1160  * Frees pages from a keg back to the system.  This is done on demand from
1161  * the pageout daemon.
1162  *
1163  * Returns nothing.
1164  */
1165 static void
1166 keg_drain(uma_keg_t keg)
1167 {
1168 	struct slabhead freeslabs = { 0 };
1169 	uma_domain_t dom;
1170 	uma_slab_t slab, tmp;
1171 	int i;
1172 
1173 	/*
1174 	 * We don't want to take pages from statically allocated kegs at this
1175 	 * time
1176 	 */
1177 	if (keg->uk_flags & UMA_ZONE_NOFREE || keg->uk_freef == NULL)
1178 		return;
1179 
1180 	CTR3(KTR_UMA, "keg_drain %s(%p) free items: %u",
1181 	    keg->uk_name, keg, keg->uk_free);
1182 	KEG_LOCK(keg);
1183 	if (keg->uk_free == 0)
1184 		goto finished;
1185 
1186 	for (i = 0; i < vm_ndomains; i++) {
1187 		dom = &keg->uk_domain[i];
1188 		LIST_FOREACH_SAFE(slab, &dom->ud_free_slab, us_link, tmp) {
1189 			/* We have nowhere to free these to. */
1190 			if (slab->us_flags & UMA_SLAB_BOOT)
1191 				continue;
1192 
1193 			LIST_REMOVE(slab, us_link);
1194 			keg->uk_pages -= keg->uk_ppera;
1195 			keg->uk_free -= keg->uk_ipers;
1196 
1197 			if (keg->uk_flags & UMA_ZONE_HASH)
1198 				UMA_HASH_REMOVE(&keg->uk_hash, slab);
1199 
1200 			LIST_INSERT_HEAD(&freeslabs, slab, us_link);
1201 		}
1202 	}
1203 
1204 finished:
1205 	KEG_UNLOCK(keg);
1206 
1207 	while ((slab = LIST_FIRST(&freeslabs)) != NULL) {
1208 		LIST_REMOVE(slab, us_link);
1209 		keg_free_slab(keg, slab, keg->uk_ipers);
1210 	}
1211 }
1212 
1213 static void
1214 zone_reclaim(uma_zone_t zone, int waitok, bool drain)
1215 {
1216 
1217 	/*
1218 	 * Set draining to interlock with zone_dtor() so we can release our
1219 	 * locks as we go.  Only dtor() should do a WAITOK call since it
1220 	 * is the only call that knows the structure will still be available
1221 	 * when it wakes up.
1222 	 */
1223 	ZONE_LOCK(zone);
1224 	while (zone->uz_flags & UMA_ZFLAG_RECLAIMING) {
1225 		if (waitok == M_NOWAIT)
1226 			goto out;
1227 		msleep(zone, zone->uz_lockptr, PVM, "zonedrain", 1);
1228 	}
1229 	zone->uz_flags |= UMA_ZFLAG_RECLAIMING;
1230 	bucket_cache_reclaim(zone, drain);
1231 	ZONE_UNLOCK(zone);
1232 
1233 	/*
1234 	 * The DRAINING flag protects us from being freed while
1235 	 * we're running.  Normally the uma_rwlock would protect us but we
1236 	 * must be able to release and acquire the right lock for each keg.
1237 	 */
1238 	if ((zone->uz_flags & UMA_ZFLAG_CACHE) == 0)
1239 		keg_drain(zone->uz_keg);
1240 	ZONE_LOCK(zone);
1241 	zone->uz_flags &= ~UMA_ZFLAG_RECLAIMING;
1242 	wakeup(zone);
1243 out:
1244 	ZONE_UNLOCK(zone);
1245 }
1246 
1247 static void
1248 zone_drain(uma_zone_t zone, void *unused)
1249 {
1250 
1251 	zone_reclaim(zone, M_NOWAIT, true);
1252 }
1253 
1254 static void
1255 zone_trim(uma_zone_t zone, void *unused)
1256 {
1257 
1258 	zone_reclaim(zone, M_NOWAIT, false);
1259 }
1260 
1261 /*
1262  * Allocate a new slab for a keg.  This does not insert the slab onto a list.
1263  * If the allocation was successful, the keg lock will be held upon return,
1264  * otherwise the keg will be left unlocked.
1265  *
1266  * Arguments:
1267  *	flags   Wait flags for the item initialization routine
1268  *	aflags  Wait flags for the slab allocation
1269  *
1270  * Returns:
1271  *	The slab that was allocated or NULL if there is no memory and the
1272  *	caller specified M_NOWAIT.
1273  */
1274 static uma_slab_t
1275 keg_alloc_slab(uma_keg_t keg, uma_zone_t zone, int domain, int flags,
1276     int aflags)
1277 {
1278 	uma_alloc allocf;
1279 	uma_slab_t slab;
1280 	unsigned long size;
1281 	uint8_t *mem;
1282 	uint8_t sflags;
1283 	int i;
1284 
1285 	KASSERT(domain >= 0 && domain < vm_ndomains,
1286 	    ("keg_alloc_slab: domain %d out of range", domain));
1287 	KEG_LOCK_ASSERT(keg);
1288 	MPASS(zone->uz_lockptr == &keg->uk_lock);
1289 
1290 	allocf = keg->uk_allocf;
1291 	KEG_UNLOCK(keg);
1292 
1293 	slab = NULL;
1294 	mem = NULL;
1295 	if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
1296 		slab = zone_alloc_item(keg->uk_slabzone, NULL, domain, aflags);
1297 		if (slab == NULL)
1298 			goto out;
1299 	}
1300 
1301 	/*
1302 	 * This reproduces the old vm_zone behavior of zero filling pages the
1303 	 * first time they are added to a zone.
1304 	 *
1305 	 * Malloced items are zeroed in uma_zalloc.
1306 	 */
1307 
1308 	if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
1309 		aflags |= M_ZERO;
1310 	else
1311 		aflags &= ~M_ZERO;
1312 
1313 	if (keg->uk_flags & UMA_ZONE_NODUMP)
1314 		aflags |= M_NODUMP;
1315 
1316 	/* zone is passed for legacy reasons. */
1317 	size = keg->uk_ppera * PAGE_SIZE;
1318 	mem = allocf(zone, size, domain, &sflags, aflags);
1319 	if (mem == NULL) {
1320 		if (keg->uk_flags & UMA_ZONE_OFFPAGE)
1321 			zone_free_item(keg->uk_slabzone, slab, NULL, SKIP_NONE);
1322 		slab = NULL;
1323 		goto out;
1324 	}
1325 	uma_total_inc(size);
1326 
1327 	/* Point the slab into the allocated memory */
1328 	if (!(keg->uk_flags & UMA_ZONE_OFFPAGE))
1329 		slab = (uma_slab_t )(mem + keg->uk_pgoff);
1330 	else
1331 		((uma_hash_slab_t)slab)->uhs_data = mem;
1332 
1333 	if (keg->uk_flags & UMA_ZONE_VTOSLAB)
1334 		for (i = 0; i < keg->uk_ppera; i++)
1335 			vsetzoneslab((vm_offset_t)mem + (i * PAGE_SIZE),
1336 			    zone, slab);
1337 
1338 	slab->us_freecount = keg->uk_ipers;
1339 	slab->us_flags = sflags;
1340 	slab->us_domain = domain;
1341 	BIT_FILL(keg->uk_ipers, &slab->us_free);
1342 #ifdef INVARIANTS
1343 	BIT_ZERO(keg->uk_ipers, slab_dbg_bits(slab, keg));
1344 #endif
1345 
1346 	if (keg->uk_init != NULL) {
1347 		for (i = 0; i < keg->uk_ipers; i++)
1348 			if (keg->uk_init(slab_item(slab, keg, i),
1349 			    keg->uk_size, flags) != 0)
1350 				break;
1351 		if (i != keg->uk_ipers) {
1352 			keg_free_slab(keg, slab, i);
1353 			slab = NULL;
1354 			goto out;
1355 		}
1356 	}
1357 	KEG_LOCK(keg);
1358 
1359 	CTR3(KTR_UMA, "keg_alloc_slab: allocated slab %p for %s(%p)",
1360 	    slab, keg->uk_name, keg);
1361 
1362 	if (keg->uk_flags & UMA_ZONE_HASH)
1363 		UMA_HASH_INSERT(&keg->uk_hash, slab, mem);
1364 
1365 	keg->uk_pages += keg->uk_ppera;
1366 	keg->uk_free += keg->uk_ipers;
1367 
1368 out:
1369 	return (slab);
1370 }
1371 
1372 /*
1373  * This function is intended to be used early on in place of page_alloc() so
1374  * that we may use the boot time page cache to satisfy allocations before
1375  * the VM is ready.
1376  */
1377 static void *
1378 startup_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
1379     int wait)
1380 {
1381 	uma_keg_t keg;
1382 	void *mem;
1383 	int pages;
1384 
1385 	keg = zone->uz_keg;
1386 	/*
1387 	 * If we are in BOOT_BUCKETS or higher, than switch to real
1388 	 * allocator.  Zones with page sized slabs switch at BOOT_PAGEALLOC.
1389 	 */
1390 	switch (booted) {
1391 		case BOOT_COLD:
1392 		case BOOT_STRAPPED:
1393 			break;
1394 		case BOOT_PAGEALLOC:
1395 			if (keg->uk_ppera > 1)
1396 				break;
1397 		case BOOT_BUCKETS:
1398 		case BOOT_RUNNING:
1399 #ifdef UMA_MD_SMALL_ALLOC
1400 			keg->uk_allocf = (keg->uk_ppera > 1) ?
1401 			    page_alloc : uma_small_alloc;
1402 #else
1403 			keg->uk_allocf = page_alloc;
1404 #endif
1405 			return keg->uk_allocf(zone, bytes, domain, pflag, wait);
1406 	}
1407 
1408 	/*
1409 	 * Check our small startup cache to see if it has pages remaining.
1410 	 */
1411 	pages = howmany(bytes, PAGE_SIZE);
1412 	KASSERT(pages > 0, ("%s can't reserve 0 pages", __func__));
1413 	if (pages > boot_pages)
1414 		panic("UMA zone \"%s\": Increase vm.boot_pages", zone->uz_name);
1415 #ifdef DIAGNOSTIC
1416 	printf("%s from \"%s\", %d boot pages left\n", __func__, zone->uz_name,
1417 	    boot_pages);
1418 #endif
1419 	mem = bootmem;
1420 	boot_pages -= pages;
1421 	bootmem += pages * PAGE_SIZE;
1422 	*pflag = UMA_SLAB_BOOT;
1423 
1424 	return (mem);
1425 }
1426 
1427 /*
1428  * Allocates a number of pages from the system
1429  *
1430  * Arguments:
1431  *	bytes  The number of bytes requested
1432  *	wait  Shall we wait?
1433  *
1434  * Returns:
1435  *	A pointer to the alloced memory or possibly
1436  *	NULL if M_NOWAIT is set.
1437  */
1438 static void *
1439 page_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
1440     int wait)
1441 {
1442 	void *p;	/* Returned page */
1443 
1444 	*pflag = UMA_SLAB_KERNEL;
1445 	p = (void *)kmem_malloc_domainset(DOMAINSET_FIXED(domain), bytes, wait);
1446 
1447 	return (p);
1448 }
1449 
1450 static void *
1451 pcpu_page_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
1452     int wait)
1453 {
1454 	struct pglist alloctail;
1455 	vm_offset_t addr, zkva;
1456 	int cpu, flags;
1457 	vm_page_t p, p_next;
1458 #ifdef NUMA
1459 	struct pcpu *pc;
1460 #endif
1461 
1462 	MPASS(bytes == (mp_maxid + 1) * PAGE_SIZE);
1463 
1464 	TAILQ_INIT(&alloctail);
1465 	flags = VM_ALLOC_SYSTEM | VM_ALLOC_WIRED | VM_ALLOC_NOOBJ |
1466 	    malloc2vm_flags(wait);
1467 	*pflag = UMA_SLAB_KERNEL;
1468 	for (cpu = 0; cpu <= mp_maxid; cpu++) {
1469 		if (CPU_ABSENT(cpu)) {
1470 			p = vm_page_alloc(NULL, 0, flags);
1471 		} else {
1472 #ifndef NUMA
1473 			p = vm_page_alloc(NULL, 0, flags);
1474 #else
1475 			pc = pcpu_find(cpu);
1476 			p = vm_page_alloc_domain(NULL, 0, pc->pc_domain, flags);
1477 			if (__predict_false(p == NULL))
1478 				p = vm_page_alloc(NULL, 0, flags);
1479 #endif
1480 		}
1481 		if (__predict_false(p == NULL))
1482 			goto fail;
1483 		TAILQ_INSERT_TAIL(&alloctail, p, listq);
1484 	}
1485 	if ((addr = kva_alloc(bytes)) == 0)
1486 		goto fail;
1487 	zkva = addr;
1488 	TAILQ_FOREACH(p, &alloctail, listq) {
1489 		pmap_qenter(zkva, &p, 1);
1490 		zkva += PAGE_SIZE;
1491 	}
1492 	return ((void*)addr);
1493 fail:
1494 	TAILQ_FOREACH_SAFE(p, &alloctail, listq, p_next) {
1495 		vm_page_unwire_noq(p);
1496 		vm_page_free(p);
1497 	}
1498 	return (NULL);
1499 }
1500 
1501 /*
1502  * Allocates a number of pages from within an object
1503  *
1504  * Arguments:
1505  *	bytes  The number of bytes requested
1506  *	wait   Shall we wait?
1507  *
1508  * Returns:
1509  *	A pointer to the alloced memory or possibly
1510  *	NULL if M_NOWAIT is set.
1511  */
1512 static void *
1513 noobj_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *flags,
1514     int wait)
1515 {
1516 	TAILQ_HEAD(, vm_page) alloctail;
1517 	u_long npages;
1518 	vm_offset_t retkva, zkva;
1519 	vm_page_t p, p_next;
1520 	uma_keg_t keg;
1521 
1522 	TAILQ_INIT(&alloctail);
1523 	keg = zone->uz_keg;
1524 
1525 	npages = howmany(bytes, PAGE_SIZE);
1526 	while (npages > 0) {
1527 		p = vm_page_alloc_domain(NULL, 0, domain, VM_ALLOC_INTERRUPT |
1528 		    VM_ALLOC_WIRED | VM_ALLOC_NOOBJ |
1529 		    ((wait & M_WAITOK) != 0 ? VM_ALLOC_WAITOK :
1530 		    VM_ALLOC_NOWAIT));
1531 		if (p != NULL) {
1532 			/*
1533 			 * Since the page does not belong to an object, its
1534 			 * listq is unused.
1535 			 */
1536 			TAILQ_INSERT_TAIL(&alloctail, p, listq);
1537 			npages--;
1538 			continue;
1539 		}
1540 		/*
1541 		 * Page allocation failed, free intermediate pages and
1542 		 * exit.
1543 		 */
1544 		TAILQ_FOREACH_SAFE(p, &alloctail, listq, p_next) {
1545 			vm_page_unwire_noq(p);
1546 			vm_page_free(p);
1547 		}
1548 		return (NULL);
1549 	}
1550 	*flags = UMA_SLAB_PRIV;
1551 	zkva = keg->uk_kva +
1552 	    atomic_fetchadd_long(&keg->uk_offset, round_page(bytes));
1553 	retkva = zkva;
1554 	TAILQ_FOREACH(p, &alloctail, listq) {
1555 		pmap_qenter(zkva, &p, 1);
1556 		zkva += PAGE_SIZE;
1557 	}
1558 
1559 	return ((void *)retkva);
1560 }
1561 
1562 /*
1563  * Frees a number of pages to the system
1564  *
1565  * Arguments:
1566  *	mem   A pointer to the memory to be freed
1567  *	size  The size of the memory being freed
1568  *	flags The original p->us_flags field
1569  *
1570  * Returns:
1571  *	Nothing
1572  */
1573 static void
1574 page_free(void *mem, vm_size_t size, uint8_t flags)
1575 {
1576 
1577 	if ((flags & UMA_SLAB_KERNEL) == 0)
1578 		panic("UMA: page_free used with invalid flags %x", flags);
1579 
1580 	kmem_free((vm_offset_t)mem, size);
1581 }
1582 
1583 /*
1584  * Frees pcpu zone allocations
1585  *
1586  * Arguments:
1587  *	mem   A pointer to the memory to be freed
1588  *	size  The size of the memory being freed
1589  *	flags The original p->us_flags field
1590  *
1591  * Returns:
1592  *	Nothing
1593  */
1594 static void
1595 pcpu_page_free(void *mem, vm_size_t size, uint8_t flags)
1596 {
1597 	vm_offset_t sva, curva;
1598 	vm_paddr_t paddr;
1599 	vm_page_t m;
1600 
1601 	MPASS(size == (mp_maxid+1)*PAGE_SIZE);
1602 	sva = (vm_offset_t)mem;
1603 	for (curva = sva; curva < sva + size; curva += PAGE_SIZE) {
1604 		paddr = pmap_kextract(curva);
1605 		m = PHYS_TO_VM_PAGE(paddr);
1606 		vm_page_unwire_noq(m);
1607 		vm_page_free(m);
1608 	}
1609 	pmap_qremove(sva, size >> PAGE_SHIFT);
1610 	kva_free(sva, size);
1611 }
1612 
1613 
1614 /*
1615  * Zero fill initializer
1616  *
1617  * Arguments/Returns follow uma_init specifications
1618  */
1619 static int
1620 zero_init(void *mem, int size, int flags)
1621 {
1622 	bzero(mem, size);
1623 	return (0);
1624 }
1625 
1626 #ifdef INVARIANTS
1627 struct noslabbits *
1628 slab_dbg_bits(uma_slab_t slab, uma_keg_t keg)
1629 {
1630 
1631 	return ((void *)((char *)&slab->us_free + BITSET_SIZE(keg->uk_ipers)));
1632 }
1633 #endif
1634 
1635 /*
1636  * Actual size of embedded struct slab (!OFFPAGE).
1637  */
1638 size_t
1639 slab_sizeof(int nitems)
1640 {
1641 	size_t s;
1642 
1643 	s = sizeof(struct uma_slab) + BITSET_SIZE(nitems) * SLAB_BITSETS;
1644 	return (roundup(s, UMA_ALIGN_PTR + 1));
1645 }
1646 
1647 /*
1648  * Size of memory for embedded slabs (!OFFPAGE).
1649  */
1650 size_t
1651 slab_space(int nitems)
1652 {
1653 	return (UMA_SLAB_SIZE - slab_sizeof(nitems));
1654 }
1655 
1656 /*
1657  * Compute the number of items that will fit in an embedded (!OFFPAGE) slab
1658  * with a given size and alignment.
1659  */
1660 int
1661 slab_ipers(size_t size, int align)
1662 {
1663 	int rsize;
1664 	int nitems;
1665 
1666         /*
1667          * Compute the ideal number of items that will fit in a page and
1668          * then compute the actual number based on a bitset nitems wide.
1669          */
1670 	rsize = roundup(size, align + 1);
1671         nitems = UMA_SLAB_SIZE / rsize;
1672 	return (slab_space(nitems) / rsize);
1673 }
1674 
1675 /*
1676  * Finish creating a small uma keg.  This calculates ipers, and the keg size.
1677  *
1678  * Arguments
1679  *	keg  The zone we should initialize
1680  *
1681  * Returns
1682  *	Nothing
1683  */
1684 static void
1685 keg_small_init(uma_keg_t keg)
1686 {
1687 	u_int rsize;
1688 	u_int memused;
1689 	u_int wastedspace;
1690 	u_int shsize;
1691 	u_int slabsize;
1692 
1693 	if (keg->uk_flags & UMA_ZONE_PCPU) {
1694 		u_int ncpus = (mp_maxid + 1) ? (mp_maxid + 1) : MAXCPU;
1695 
1696 		slabsize = UMA_PCPU_ALLOC_SIZE;
1697 		keg->uk_ppera = ncpus;
1698 	} else {
1699 		slabsize = UMA_SLAB_SIZE;
1700 		keg->uk_ppera = 1;
1701 	}
1702 
1703 	/*
1704 	 * Calculate the size of each allocation (rsize) according to
1705 	 * alignment.  If the requested size is smaller than we have
1706 	 * allocation bits for we round it up.
1707 	 */
1708 	rsize = keg->uk_size;
1709 	if (rsize < slabsize / SLAB_MAX_SETSIZE)
1710 		rsize = slabsize / SLAB_MAX_SETSIZE;
1711 	if (rsize & keg->uk_align)
1712 		rsize = roundup(rsize, keg->uk_align + 1);
1713 	keg->uk_rsize = rsize;
1714 
1715 	KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0 ||
1716 	    keg->uk_rsize < UMA_PCPU_ALLOC_SIZE,
1717 	    ("%s: size %u too large", __func__, keg->uk_rsize));
1718 
1719 	/*
1720 	 * Use a pessimistic bit count for shsize.  It may be possible to
1721 	 * squeeze one more item in for very particular sizes if we were
1722 	 * to loop and reduce the bitsize if there is waste.
1723 	 */
1724 	if (keg->uk_flags & UMA_ZONE_OFFPAGE)
1725 		shsize = 0;
1726 	else
1727 		shsize = slab_sizeof(slabsize / rsize);
1728 
1729 	if (rsize <= slabsize - shsize)
1730 		keg->uk_ipers = (slabsize - shsize) / rsize;
1731 	else {
1732 		/* Handle special case when we have 1 item per slab, so
1733 		 * alignment requirement can be relaxed. */
1734 		KASSERT(keg->uk_size <= slabsize - shsize,
1735 		    ("%s: size %u greater than slab", __func__, keg->uk_size));
1736 		keg->uk_ipers = 1;
1737 	}
1738 	KASSERT(keg->uk_ipers > 0 && keg->uk_ipers <= SLAB_MAX_SETSIZE,
1739 	    ("%s: keg->uk_ipers %u", __func__, keg->uk_ipers));
1740 
1741 	memused = keg->uk_ipers * rsize + shsize;
1742 	wastedspace = slabsize - memused;
1743 
1744 	/*
1745 	 * We can't do OFFPAGE if we're internal or if we've been
1746 	 * asked to not go to the VM for buckets.  If we do this we
1747 	 * may end up going to the VM  for slabs which we do not
1748 	 * want to do if we're UMA_ZFLAG_CACHEONLY as a result
1749 	 * of UMA_ZONE_VM, which clearly forbids it.
1750 	 */
1751 	if ((keg->uk_flags & UMA_ZFLAG_INTERNAL) ||
1752 	    (keg->uk_flags & UMA_ZFLAG_CACHEONLY))
1753 		return;
1754 
1755 	/*
1756 	 * See if using an OFFPAGE slab will limit our waste.  Only do
1757 	 * this if it permits more items per-slab.
1758 	 *
1759 	 * XXX We could try growing slabsize to limit max waste as well.
1760 	 * Historically this was not done because the VM could not
1761 	 * efficiently handle contiguous allocations.
1762 	 */
1763 	if ((wastedspace >= slabsize / UMA_MAX_WASTE) &&
1764 	    (keg->uk_ipers < (slabsize / keg->uk_rsize))) {
1765 		keg->uk_ipers = slabsize / keg->uk_rsize;
1766 		KASSERT(keg->uk_ipers > 0 && keg->uk_ipers <= SLAB_MAX_SETSIZE,
1767 		    ("%s: keg->uk_ipers %u", __func__, keg->uk_ipers));
1768 		CTR6(KTR_UMA, "UMA decided we need offpage slab headers for "
1769 		    "keg: %s(%p), calculated wastedspace = %d, "
1770 		    "maximum wasted space allowed = %d, "
1771 		    "calculated ipers = %d, "
1772 		    "new wasted space = %d\n", keg->uk_name, keg, wastedspace,
1773 		    slabsize / UMA_MAX_WASTE, keg->uk_ipers,
1774 		    slabsize - keg->uk_ipers * keg->uk_rsize);
1775 		/*
1776 		 * If we had access to memory to embed a slab header we
1777 		 * also have a page structure to use vtoslab() instead of
1778 		 * hash to find slabs.  If the zone was explicitly created
1779 		 * OFFPAGE we can't necessarily touch the memory.
1780 		 */
1781 		if ((keg->uk_flags & UMA_ZONE_OFFPAGE) == 0)
1782 			keg->uk_flags |= UMA_ZONE_OFFPAGE | UMA_ZONE_VTOSLAB;
1783 	}
1784 
1785 	if ((keg->uk_flags & UMA_ZONE_OFFPAGE) &&
1786 	    (keg->uk_flags & UMA_ZONE_VTOSLAB) == 0)
1787 		keg->uk_flags |= UMA_ZONE_HASH;
1788 }
1789 
1790 /*
1791  * Finish creating a large (> UMA_SLAB_SIZE) uma kegs.  Just give in and do
1792  * OFFPAGE for now.  When I can allow for more dynamic slab sizes this will be
1793  * more complicated.
1794  *
1795  * Arguments
1796  *	keg  The keg we should initialize
1797  *
1798  * Returns
1799  *	Nothing
1800  */
1801 static void
1802 keg_large_init(uma_keg_t keg)
1803 {
1804 
1805 	KASSERT(keg != NULL, ("Keg is null in keg_large_init"));
1806 	KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0,
1807 	    ("%s: Cannot large-init a UMA_ZONE_PCPU keg", __func__));
1808 
1809 	keg->uk_ppera = howmany(keg->uk_size, PAGE_SIZE);
1810 	keg->uk_ipers = 1;
1811 	keg->uk_rsize = keg->uk_size;
1812 
1813 	/* Check whether we have enough space to not do OFFPAGE. */
1814 	if ((keg->uk_flags & UMA_ZONE_OFFPAGE) == 0 &&
1815 	    PAGE_SIZE * keg->uk_ppera - keg->uk_rsize <
1816 	    slab_sizeof(SLAB_MIN_SETSIZE)) {
1817 		/*
1818 		 * We can't do OFFPAGE if we're internal, in which case
1819 		 * we need an extra page per allocation to contain the
1820 		 * slab header.
1821 		 */
1822 		if ((keg->uk_flags & UMA_ZFLAG_INTERNAL) == 0)
1823 			keg->uk_flags |= UMA_ZONE_OFFPAGE | UMA_ZONE_VTOSLAB;
1824 		else
1825 			keg->uk_ppera++;
1826 	}
1827 
1828 	if ((keg->uk_flags & UMA_ZONE_OFFPAGE) &&
1829 	    (keg->uk_flags & UMA_ZONE_VTOSLAB) == 0)
1830 		keg->uk_flags |= UMA_ZONE_HASH;
1831 }
1832 
1833 static void
1834 keg_cachespread_init(uma_keg_t keg)
1835 {
1836 	int alignsize;
1837 	int trailer;
1838 	int pages;
1839 	int rsize;
1840 
1841 	KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0,
1842 	    ("%s: Cannot cachespread-init a UMA_ZONE_PCPU keg", __func__));
1843 
1844 	alignsize = keg->uk_align + 1;
1845 	rsize = keg->uk_size;
1846 	/*
1847 	 * We want one item to start on every align boundary in a page.  To
1848 	 * do this we will span pages.  We will also extend the item by the
1849 	 * size of align if it is an even multiple of align.  Otherwise, it
1850 	 * would fall on the same boundary every time.
1851 	 */
1852 	if (rsize & keg->uk_align)
1853 		rsize = (rsize & ~keg->uk_align) + alignsize;
1854 	if ((rsize & alignsize) == 0)
1855 		rsize += alignsize;
1856 	trailer = rsize - keg->uk_size;
1857 	pages = (rsize * (PAGE_SIZE / alignsize)) / PAGE_SIZE;
1858 	pages = MIN(pages, (128 * 1024) / PAGE_SIZE);
1859 	keg->uk_rsize = rsize;
1860 	keg->uk_ppera = pages;
1861 	keg->uk_ipers = ((pages * PAGE_SIZE) + trailer) / rsize;
1862 	keg->uk_flags |= UMA_ZONE_OFFPAGE | UMA_ZONE_VTOSLAB;
1863 	KASSERT(keg->uk_ipers <= SLAB_MAX_SETSIZE,
1864 	    ("%s: keg->uk_ipers too high(%d) increase max_ipers", __func__,
1865 	    keg->uk_ipers));
1866 }
1867 
1868 /*
1869  * Keg header ctor.  This initializes all fields, locks, etc.  And inserts
1870  * the keg onto the global keg list.
1871  *
1872  * Arguments/Returns follow uma_ctor specifications
1873  *	udata  Actually uma_kctor_args
1874  */
1875 static int
1876 keg_ctor(void *mem, int size, void *udata, int flags)
1877 {
1878 	struct uma_kctor_args *arg = udata;
1879 	uma_keg_t keg = mem;
1880 	uma_zone_t zone;
1881 
1882 	bzero(keg, size);
1883 	keg->uk_size = arg->size;
1884 	keg->uk_init = arg->uminit;
1885 	keg->uk_fini = arg->fini;
1886 	keg->uk_align = arg->align;
1887 	keg->uk_free = 0;
1888 	keg->uk_reserve = 0;
1889 	keg->uk_pages = 0;
1890 	keg->uk_flags = arg->flags;
1891 	keg->uk_slabzone = NULL;
1892 
1893 	/*
1894 	 * We use a global round-robin policy by default.  Zones with
1895 	 * UMA_ZONE_NUMA set will use first-touch instead, in which case the
1896 	 * iterator is never run.
1897 	 */
1898 	keg->uk_dr.dr_policy = DOMAINSET_RR();
1899 	keg->uk_dr.dr_iter = 0;
1900 
1901 	/*
1902 	 * The master zone is passed to us at keg-creation time.
1903 	 */
1904 	zone = arg->zone;
1905 	keg->uk_name = zone->uz_name;
1906 
1907 	if (arg->flags & UMA_ZONE_VM)
1908 		keg->uk_flags |= UMA_ZFLAG_CACHEONLY;
1909 
1910 	if (arg->flags & UMA_ZONE_ZINIT)
1911 		keg->uk_init = zero_init;
1912 
1913 	if (arg->flags & UMA_ZONE_MALLOC)
1914 		keg->uk_flags |= UMA_ZONE_VTOSLAB;
1915 
1916 	if (arg->flags & UMA_ZONE_PCPU)
1917 #ifdef SMP
1918 		keg->uk_flags |= UMA_ZONE_OFFPAGE;
1919 #else
1920 		keg->uk_flags &= ~UMA_ZONE_PCPU;
1921 #endif
1922 
1923 	if (keg->uk_flags & UMA_ZONE_CACHESPREAD) {
1924 		keg_cachespread_init(keg);
1925 	} else {
1926 		if (keg->uk_size > slab_space(SLAB_MIN_SETSIZE))
1927 			keg_large_init(keg);
1928 		else
1929 			keg_small_init(keg);
1930 	}
1931 
1932 	if (keg->uk_flags & UMA_ZONE_OFFPAGE)
1933 		keg->uk_slabzone = slabzone;
1934 
1935 	/*
1936 	 * If we haven't booted yet we need allocations to go through the
1937 	 * startup cache until the vm is ready.
1938 	 */
1939 	if (booted < BOOT_PAGEALLOC)
1940 		keg->uk_allocf = startup_alloc;
1941 #ifdef UMA_MD_SMALL_ALLOC
1942 	else if (keg->uk_ppera == 1)
1943 		keg->uk_allocf = uma_small_alloc;
1944 #endif
1945 	else if (keg->uk_flags & UMA_ZONE_PCPU)
1946 		keg->uk_allocf = pcpu_page_alloc;
1947 	else
1948 		keg->uk_allocf = page_alloc;
1949 #ifdef UMA_MD_SMALL_ALLOC
1950 	if (keg->uk_ppera == 1)
1951 		keg->uk_freef = uma_small_free;
1952 	else
1953 #endif
1954 	if (keg->uk_flags & UMA_ZONE_PCPU)
1955 		keg->uk_freef = pcpu_page_free;
1956 	else
1957 		keg->uk_freef = page_free;
1958 
1959 	/*
1960 	 * Initialize keg's lock
1961 	 */
1962 	KEG_LOCK_INIT(keg, (arg->flags & UMA_ZONE_MTXCLASS));
1963 
1964 	/*
1965 	 * If we're putting the slab header in the actual page we need to
1966 	 * figure out where in each page it goes.  See slab_sizeof
1967 	 * definition.
1968 	 */
1969 	if (!(keg->uk_flags & UMA_ZONE_OFFPAGE)) {
1970 		size_t shsize;
1971 
1972 		shsize = slab_sizeof(keg->uk_ipers);
1973 		keg->uk_pgoff = (PAGE_SIZE * keg->uk_ppera) - shsize;
1974 		/*
1975 		 * The only way the following is possible is if with our
1976 		 * UMA_ALIGN_PTR adjustments we are now bigger than
1977 		 * UMA_SLAB_SIZE.  I haven't checked whether this is
1978 		 * mathematically possible for all cases, so we make
1979 		 * sure here anyway.
1980 		 */
1981 		KASSERT(keg->uk_pgoff + shsize <= PAGE_SIZE * keg->uk_ppera,
1982 		    ("zone %s ipers %d rsize %d size %d slab won't fit",
1983 		    zone->uz_name, keg->uk_ipers, keg->uk_rsize, keg->uk_size));
1984 	}
1985 
1986 	if (keg->uk_flags & UMA_ZONE_HASH)
1987 		hash_alloc(&keg->uk_hash, 0);
1988 
1989 	CTR5(KTR_UMA, "keg_ctor %p zone %s(%p) out %d free %d\n",
1990 	    keg, zone->uz_name, zone,
1991 	    (keg->uk_pages / keg->uk_ppera) * keg->uk_ipers - keg->uk_free,
1992 	    keg->uk_free);
1993 
1994 	LIST_INSERT_HEAD(&keg->uk_zones, zone, uz_link);
1995 
1996 	rw_wlock(&uma_rwlock);
1997 	LIST_INSERT_HEAD(&uma_kegs, keg, uk_link);
1998 	rw_wunlock(&uma_rwlock);
1999 	return (0);
2000 }
2001 
2002 static void
2003 zone_alloc_counters(uma_zone_t zone, void *unused)
2004 {
2005 
2006 	zone->uz_allocs = counter_u64_alloc(M_WAITOK);
2007 	zone->uz_frees = counter_u64_alloc(M_WAITOK);
2008 	zone->uz_fails = counter_u64_alloc(M_WAITOK);
2009 }
2010 
2011 static void
2012 zone_alloc_sysctl(uma_zone_t zone, void *unused)
2013 {
2014 	uma_zone_domain_t zdom;
2015 	uma_keg_t keg;
2016 	struct sysctl_oid *oid, *domainoid;
2017 	int domains, i, cnt;
2018 	static const char *nokeg = "cache zone";
2019 	char *c;
2020 
2021 	/*
2022 	 * Make a sysctl safe copy of the zone name by removing
2023 	 * any special characters and handling dups by appending
2024 	 * an index.
2025 	 */
2026 	if (zone->uz_namecnt != 0) {
2027 		/* Count the number of decimal digits and '_' separator. */
2028 		for (i = 1, cnt = zone->uz_namecnt; cnt != 0; i++)
2029 			cnt /= 10;
2030 		zone->uz_ctlname = malloc(strlen(zone->uz_name) + i + 1,
2031 		    M_UMA, M_WAITOK);
2032 		sprintf(zone->uz_ctlname, "%s_%d", zone->uz_name,
2033 		    zone->uz_namecnt);
2034 	} else
2035 		zone->uz_ctlname = strdup(zone->uz_name, M_UMA);
2036 	for (c = zone->uz_ctlname; *c != '\0'; c++)
2037 		if (strchr("./\\ -", *c) != NULL)
2038 			*c = '_';
2039 
2040 	/*
2041 	 * Basic parameters at the root.
2042 	 */
2043 	zone->uz_oid = SYSCTL_ADD_NODE(NULL, SYSCTL_STATIC_CHILDREN(_vm_uma),
2044 	    OID_AUTO, zone->uz_ctlname, CTLFLAG_RD, NULL, "");
2045 	oid = zone->uz_oid;
2046 	SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2047 	    "size", CTLFLAG_RD, &zone->uz_size, 0, "Allocation size");
2048 	SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2049 	    "flags", CTLFLAG_RD | CTLTYPE_STRING | CTLFLAG_MPSAFE,
2050 	    zone, 0, sysctl_handle_uma_zone_flags, "A",
2051 	    "Allocator configuration flags");
2052 	SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2053 	    "bucket_size", CTLFLAG_RD, &zone->uz_bucket_size, 0,
2054 	    "Desired per-cpu cache size");
2055 	SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2056 	    "bucket_size_max", CTLFLAG_RD, &zone->uz_bucket_size_max, 0,
2057 	    "Maximum allowed per-cpu cache size");
2058 
2059 	/*
2060 	 * keg if present.
2061 	 */
2062 	oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid), OID_AUTO,
2063 	    "keg", CTLFLAG_RD, NULL, "");
2064 	keg = zone->uz_keg;
2065 	if ((zone->uz_flags & UMA_ZFLAG_CACHE) == 0) {
2066 		SYSCTL_ADD_CONST_STRING(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2067 		    "name", CTLFLAG_RD, keg->uk_name, "Keg name");
2068 		SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2069 		    "rsize", CTLFLAG_RD, &keg->uk_rsize, 0,
2070 		    "Real object size with alignment");
2071 		SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2072 		    "ppera", CTLFLAG_RD, &keg->uk_ppera, 0,
2073 		    "pages per-slab allocation");
2074 		SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2075 		    "ipers", CTLFLAG_RD, &keg->uk_ipers, 0,
2076 		    "items available per-slab");
2077 		SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2078 		    "align", CTLFLAG_RD, &keg->uk_align, 0,
2079 		    "item alignment mask");
2080 		SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2081 		    "pages", CTLFLAG_RD, &keg->uk_pages, 0,
2082 		    "Total pages currently allocated from VM");
2083 		SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2084 		    "free", CTLFLAG_RD, &keg->uk_free, 0,
2085 		    "items free in the slab layer");
2086 		SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2087 		    "efficiency", CTLFLAG_RD | CTLTYPE_INT | CTLFLAG_MPSAFE,
2088 		    keg, 0, sysctl_handle_uma_slab_efficiency, "I",
2089 		    "Slab utilization (100 - internal fragmentation %)");
2090 	} else
2091 		SYSCTL_ADD_CONST_STRING(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2092 		    "name", CTLFLAG_RD, nokeg, "Keg name");
2093 
2094 	/*
2095 	 * Information about zone limits.
2096 	 */
2097 	oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid), OID_AUTO,
2098 	    "limit", CTLFLAG_RD, NULL, "");
2099 	SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2100 	    "items", CTLFLAG_RD, &zone->uz_items, 0,
2101 	    "current number of cached items");
2102 	SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2103 	    "max_items", CTLFLAG_RD, &zone->uz_max_items, 0,
2104 	    "Maximum number of cached items");
2105 	SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2106 	    "sleepers", CTLFLAG_RD, &zone->uz_sleepers, 0,
2107 	    "Number of threads sleeping at limit");
2108 	SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2109 	    "sleeps", CTLFLAG_RD, &zone->uz_sleeps, 0,
2110 	    "Total zone limit sleeps");
2111 
2112 	/*
2113 	 * Per-domain information.
2114 	 */
2115 	if ((zone->uz_flags & UMA_ZONE_NUMA) != 0)
2116 		domains = vm_ndomains;
2117 	else
2118 		domains = 1;
2119 	domainoid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid),
2120 	    OID_AUTO, "domain", CTLFLAG_RD, NULL, "");
2121 	for (i = 0; i < domains; i++) {
2122 		zdom = &zone->uz_domain[i];
2123 		oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(domainoid),
2124 		    OID_AUTO, VM_DOMAIN(i)->vmd_name, CTLFLAG_RD, NULL, "");
2125 		SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2126 		    "nitems", CTLFLAG_RD, &zdom->uzd_nitems,
2127 		    "number of items in this domain");
2128 		SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2129 		    "imax", CTLFLAG_RD, &zdom->uzd_imax,
2130 		    "maximum item count in this period");
2131 		SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2132 		    "imin", CTLFLAG_RD, &zdom->uzd_imin,
2133 		    "minimum item count in this period");
2134 		SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2135 		    "wss", CTLFLAG_RD, &zdom->uzd_wss,
2136 		    "Working set size");
2137 	}
2138 
2139 	/*
2140 	 * General statistics.
2141 	 */
2142 	oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid), OID_AUTO,
2143 	    "stats", CTLFLAG_RD, NULL, "");
2144 	SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2145 	    "current", CTLFLAG_RD | CTLTYPE_INT | CTLFLAG_MPSAFE,
2146 	    zone, 1, sysctl_handle_uma_zone_cur, "I",
2147 	    "Current number of allocated items");
2148 	SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2149 	    "allocs", CTLFLAG_RD | CTLTYPE_U64 | CTLFLAG_MPSAFE,
2150 	    zone, 0, sysctl_handle_uma_zone_allocs, "QU",
2151 	    "Total allocation calls");
2152 	SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2153 	    "frees", CTLFLAG_RD | CTLTYPE_U64 | CTLFLAG_MPSAFE,
2154 	    zone, 0, sysctl_handle_uma_zone_frees, "QU",
2155 	    "Total free calls");
2156 	SYSCTL_ADD_COUNTER_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2157 	    "fails", CTLFLAG_RD, &zone->uz_fails,
2158 	    "Number of allocation failures");
2159 	SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2160 	    "xdomain", CTLFLAG_RD, &zone->uz_xdomain, 0,
2161 	    "Free calls from the wrong domain");
2162 }
2163 
2164 struct uma_zone_count {
2165 	const char	*name;
2166 	int		count;
2167 };
2168 
2169 static void
2170 zone_count(uma_zone_t zone, void *arg)
2171 {
2172 	struct uma_zone_count *cnt;
2173 
2174 	cnt = arg;
2175 	/*
2176 	 * Some zones are rapidly created with identical names and
2177 	 * destroyed out of order.  This can lead to gaps in the count.
2178 	 * Use one greater than the maximum observed for this name.
2179 	 */
2180 	if (strcmp(zone->uz_name, cnt->name) == 0)
2181 		cnt->count = MAX(cnt->count,
2182 		    zone->uz_namecnt + 1);
2183 }
2184 
2185 static void
2186 zone_update_caches(uma_zone_t zone)
2187 {
2188 	int i;
2189 
2190 	for (i = 0; i <= mp_maxid; i++) {
2191 		cache_set_uz_size(&zone->uz_cpu[i], zone->uz_size);
2192 		cache_set_uz_flags(&zone->uz_cpu[i], zone->uz_flags);
2193 	}
2194 }
2195 
2196 /*
2197  * Zone header ctor.  This initializes all fields, locks, etc.
2198  *
2199  * Arguments/Returns follow uma_ctor specifications
2200  *	udata  Actually uma_zctor_args
2201  */
2202 static int
2203 zone_ctor(void *mem, int size, void *udata, int flags)
2204 {
2205 	struct uma_zone_count cnt;
2206 	struct uma_zctor_args *arg = udata;
2207 	uma_zone_t zone = mem;
2208 	uma_zone_t z;
2209 	uma_keg_t keg;
2210 	int i;
2211 
2212 	bzero(zone, size);
2213 	zone->uz_name = arg->name;
2214 	zone->uz_ctor = arg->ctor;
2215 	zone->uz_dtor = arg->dtor;
2216 	zone->uz_init = NULL;
2217 	zone->uz_fini = NULL;
2218 	zone->uz_sleeps = 0;
2219 	zone->uz_xdomain = 0;
2220 	zone->uz_bucket_size = 0;
2221 	zone->uz_bucket_size_min = 0;
2222 	zone->uz_bucket_size_max = BUCKET_MAX;
2223 	zone->uz_flags = 0;
2224 	zone->uz_warning = NULL;
2225 	/* The domain structures follow the cpu structures. */
2226 	zone->uz_domain = (struct uma_zone_domain *)&zone->uz_cpu[mp_ncpus];
2227 	zone->uz_bkt_max = ULONG_MAX;
2228 	timevalclear(&zone->uz_ratecheck);
2229 
2230 	/* Count the number of duplicate names. */
2231 	cnt.name = arg->name;
2232 	cnt.count = 0;
2233 	zone_foreach(zone_count, &cnt);
2234 	zone->uz_namecnt = cnt.count;
2235 
2236 	for (i = 0; i < vm_ndomains; i++)
2237 		TAILQ_INIT(&zone->uz_domain[i].uzd_buckets);
2238 
2239 #ifdef INVARIANTS
2240 	if (arg->uminit == trash_init && arg->fini == trash_fini)
2241 		zone->uz_flags |= UMA_ZFLAG_TRASH | UMA_ZFLAG_CTORDTOR;
2242 #endif
2243 
2244 	/*
2245 	 * This is a pure cache zone, no kegs.
2246 	 */
2247 	if (arg->import) {
2248 		if (arg->flags & UMA_ZONE_VM)
2249 			arg->flags |= UMA_ZFLAG_CACHEONLY;
2250 		zone->uz_flags = arg->flags;
2251 		zone->uz_size = arg->size;
2252 		zone->uz_import = arg->import;
2253 		zone->uz_release = arg->release;
2254 		zone->uz_arg = arg->arg;
2255 		zone->uz_lockptr = &zone->uz_lock;
2256 		ZONE_LOCK_INIT(zone, (arg->flags & UMA_ZONE_MTXCLASS));
2257 		rw_wlock(&uma_rwlock);
2258 		LIST_INSERT_HEAD(&uma_cachezones, zone, uz_link);
2259 		rw_wunlock(&uma_rwlock);
2260 		goto out;
2261 	}
2262 
2263 	/*
2264 	 * Use the regular zone/keg/slab allocator.
2265 	 */
2266 	zone->uz_import = zone_import;
2267 	zone->uz_release = zone_release;
2268 	zone->uz_arg = zone;
2269 	keg = arg->keg;
2270 
2271 	if (arg->flags & UMA_ZONE_SECONDARY) {
2272 		KASSERT((zone->uz_flags & UMA_ZONE_SECONDARY) == 0,
2273 		    ("Secondary zone requested UMA_ZFLAG_INTERNAL"));
2274 		KASSERT(arg->keg != NULL, ("Secondary zone on zero'd keg"));
2275 		zone->uz_init = arg->uminit;
2276 		zone->uz_fini = arg->fini;
2277 		zone->uz_lockptr = &keg->uk_lock;
2278 		zone->uz_flags |= UMA_ZONE_SECONDARY;
2279 		rw_wlock(&uma_rwlock);
2280 		ZONE_LOCK(zone);
2281 		LIST_FOREACH(z, &keg->uk_zones, uz_link) {
2282 			if (LIST_NEXT(z, uz_link) == NULL) {
2283 				LIST_INSERT_AFTER(z, zone, uz_link);
2284 				break;
2285 			}
2286 		}
2287 		ZONE_UNLOCK(zone);
2288 		rw_wunlock(&uma_rwlock);
2289 	} else if (keg == NULL) {
2290 		if ((keg = uma_kcreate(zone, arg->size, arg->uminit, arg->fini,
2291 		    arg->align, arg->flags)) == NULL)
2292 			return (ENOMEM);
2293 	} else {
2294 		struct uma_kctor_args karg;
2295 		int error;
2296 
2297 		/* We should only be here from uma_startup() */
2298 		karg.size = arg->size;
2299 		karg.uminit = arg->uminit;
2300 		karg.fini = arg->fini;
2301 		karg.align = arg->align;
2302 		karg.flags = arg->flags;
2303 		karg.zone = zone;
2304 		error = keg_ctor(arg->keg, sizeof(struct uma_keg), &karg,
2305 		    flags);
2306 		if (error)
2307 			return (error);
2308 	}
2309 
2310 	/* Inherit properties from the keg. */
2311 	zone->uz_keg = keg;
2312 	zone->uz_size = keg->uk_size;
2313 	zone->uz_flags |= (keg->uk_flags &
2314 	    (UMA_ZONE_INHERIT | UMA_ZFLAG_INHERIT));
2315 
2316 out:
2317 	if (__predict_true(booted == BOOT_RUNNING)) {
2318 		zone_alloc_counters(zone, NULL);
2319 		zone_alloc_sysctl(zone, NULL);
2320 	} else {
2321 		zone->uz_allocs = EARLY_COUNTER;
2322 		zone->uz_frees = EARLY_COUNTER;
2323 		zone->uz_fails = EARLY_COUNTER;
2324 	}
2325 
2326 	KASSERT((arg->flags & (UMA_ZONE_MAXBUCKET | UMA_ZONE_NOBUCKET)) !=
2327 	    (UMA_ZONE_MAXBUCKET | UMA_ZONE_NOBUCKET),
2328 	    ("Invalid zone flag combination"));
2329 	if (arg->flags & UMA_ZFLAG_INTERNAL)
2330 		zone->uz_bucket_size_max = zone->uz_bucket_size = 0;
2331 	if ((arg->flags & UMA_ZONE_MAXBUCKET) != 0)
2332 		zone->uz_bucket_size = BUCKET_MAX;
2333 	else if ((arg->flags & UMA_ZONE_MINBUCKET) != 0)
2334 		zone->uz_bucket_size_max = zone->uz_bucket_size = BUCKET_MIN;
2335 	else if ((arg->flags & UMA_ZONE_NOBUCKET) != 0)
2336 		zone->uz_bucket_size = 0;
2337 	else
2338 		zone->uz_bucket_size = bucket_select(zone->uz_size);
2339 	zone->uz_bucket_size_min = zone->uz_bucket_size;
2340 	if (zone->uz_dtor != NULL || zone->uz_ctor != NULL)
2341 		zone->uz_flags |= UMA_ZFLAG_CTORDTOR;
2342 	zone_update_caches(zone);
2343 
2344 	return (0);
2345 }
2346 
2347 /*
2348  * Keg header dtor.  This frees all data, destroys locks, frees the hash
2349  * table and removes the keg from the global list.
2350  *
2351  * Arguments/Returns follow uma_dtor specifications
2352  *	udata  unused
2353  */
2354 static void
2355 keg_dtor(void *arg, int size, void *udata)
2356 {
2357 	uma_keg_t keg;
2358 
2359 	keg = (uma_keg_t)arg;
2360 	KEG_LOCK(keg);
2361 	if (keg->uk_free != 0) {
2362 		printf("Freed UMA keg (%s) was not empty (%d items). "
2363 		    " Lost %d pages of memory.\n",
2364 		    keg->uk_name ? keg->uk_name : "",
2365 		    keg->uk_free, keg->uk_pages);
2366 	}
2367 	KEG_UNLOCK(keg);
2368 
2369 	hash_free(&keg->uk_hash);
2370 
2371 	KEG_LOCK_FINI(keg);
2372 }
2373 
2374 /*
2375  * Zone header dtor.
2376  *
2377  * Arguments/Returns follow uma_dtor specifications
2378  *	udata  unused
2379  */
2380 static void
2381 zone_dtor(void *arg, int size, void *udata)
2382 {
2383 	uma_zone_t zone;
2384 	uma_keg_t keg;
2385 
2386 	zone = (uma_zone_t)arg;
2387 
2388 	sysctl_remove_oid(zone->uz_oid, 1, 1);
2389 
2390 	if (!(zone->uz_flags & UMA_ZFLAG_INTERNAL))
2391 		cache_drain(zone);
2392 
2393 	rw_wlock(&uma_rwlock);
2394 	LIST_REMOVE(zone, uz_link);
2395 	rw_wunlock(&uma_rwlock);
2396 	/*
2397 	 * XXX there are some races here where
2398 	 * the zone can be drained but zone lock
2399 	 * released and then refilled before we
2400 	 * remove it... we dont care for now
2401 	 */
2402 	zone_reclaim(zone, M_WAITOK, true);
2403 	/*
2404 	 * We only destroy kegs from non secondary/non cache zones.
2405 	 */
2406 	if ((zone->uz_flags & (UMA_ZONE_SECONDARY | UMA_ZFLAG_CACHE)) == 0) {
2407 		keg = zone->uz_keg;
2408 		rw_wlock(&uma_rwlock);
2409 		LIST_REMOVE(keg, uk_link);
2410 		rw_wunlock(&uma_rwlock);
2411 		zone_free_item(kegs, keg, NULL, SKIP_NONE);
2412 	}
2413 	counter_u64_free(zone->uz_allocs);
2414 	counter_u64_free(zone->uz_frees);
2415 	counter_u64_free(zone->uz_fails);
2416 	free(zone->uz_ctlname, M_UMA);
2417 	if (zone->uz_lockptr == &zone->uz_lock)
2418 		ZONE_LOCK_FINI(zone);
2419 }
2420 
2421 /*
2422  * Traverses every zone in the system and calls a callback
2423  *
2424  * Arguments:
2425  *	zfunc  A pointer to a function which accepts a zone
2426  *		as an argument.
2427  *
2428  * Returns:
2429  *	Nothing
2430  */
2431 static void
2432 zone_foreach(void (*zfunc)(uma_zone_t, void *arg), void *arg)
2433 {
2434 	uma_keg_t keg;
2435 	uma_zone_t zone;
2436 
2437 	/*
2438 	 * Before BOOT_RUNNING we are guaranteed to be single
2439 	 * threaded, so locking isn't needed. Startup functions
2440 	 * are allowed to use M_WAITOK.
2441 	 */
2442 	if (__predict_true(booted == BOOT_RUNNING))
2443 		rw_rlock(&uma_rwlock);
2444 	LIST_FOREACH(keg, &uma_kegs, uk_link) {
2445 		LIST_FOREACH(zone, &keg->uk_zones, uz_link)
2446 			zfunc(zone, arg);
2447 	}
2448 	LIST_FOREACH(zone, &uma_cachezones, uz_link)
2449 		zfunc(zone, arg);
2450 	if (__predict_true(booted == BOOT_RUNNING))
2451 		rw_runlock(&uma_rwlock);
2452 }
2453 
2454 /*
2455  * Count how many pages do we need to bootstrap.  VM supplies
2456  * its need in early zones in the argument, we add up our zones,
2457  * which consist of the UMA Slabs, UMA Hash and 9 Bucket zones.  The
2458  * zone of zones and zone of kegs are accounted separately.
2459  */
2460 #define	UMA_BOOT_ZONES	11
2461 /* Zone of zones and zone of kegs have arbitrary alignment. */
2462 #define	UMA_BOOT_ALIGN	32
2463 static int zsize, ksize;
2464 int
2465 uma_startup_count(int vm_zones)
2466 {
2467 	int zones, pages;
2468 	size_t space, size;
2469 
2470 	ksize = sizeof(struct uma_keg) +
2471 	    (sizeof(struct uma_domain) * vm_ndomains);
2472 	zsize = sizeof(struct uma_zone) +
2473 	    (sizeof(struct uma_cache) * (mp_maxid + 1)) +
2474 	    (sizeof(struct uma_zone_domain) * vm_ndomains);
2475 
2476 	/*
2477 	 * Memory for the zone of kegs and its keg,
2478 	 * and for zone of zones.
2479 	 */
2480 	pages = howmany(roundup(zsize, CACHE_LINE_SIZE) * 2 +
2481 	    roundup(ksize, CACHE_LINE_SIZE), PAGE_SIZE);
2482 
2483 #ifdef	UMA_MD_SMALL_ALLOC
2484 	zones = UMA_BOOT_ZONES;
2485 #else
2486 	zones = UMA_BOOT_ZONES + vm_zones;
2487 	vm_zones = 0;
2488 #endif
2489 	size = slab_sizeof(SLAB_MAX_SETSIZE);
2490 	space = slab_space(SLAB_MAX_SETSIZE);
2491 
2492 	/* Memory for the rest of startup zones, UMA and VM, ... */
2493 	if (zsize > space) {
2494 		/* See keg_large_init(). */
2495 		u_int ppera;
2496 
2497 		ppera = howmany(roundup2(zsize, UMA_BOOT_ALIGN), PAGE_SIZE);
2498 		if (PAGE_SIZE * ppera - roundup2(zsize, UMA_BOOT_ALIGN) < size)
2499 			ppera++;
2500 		pages += (zones + vm_zones) * ppera;
2501 	} else if (roundup2(zsize, UMA_BOOT_ALIGN) > space)
2502 		/* See keg_small_init() special case for uk_ppera = 1. */
2503 		pages += zones;
2504 	else
2505 		pages += howmany(zones,
2506 		    space / roundup2(zsize, UMA_BOOT_ALIGN));
2507 
2508 	/* ... and their kegs. Note that zone of zones allocates a keg! */
2509 	pages += howmany(zones + 1,
2510 	    space / roundup2(ksize, UMA_BOOT_ALIGN));
2511 
2512 	return (pages);
2513 }
2514 
2515 void
2516 uma_startup(void *mem, int npages)
2517 {
2518 	struct uma_zctor_args args;
2519 	uma_keg_t masterkeg;
2520 	uintptr_t m;
2521 
2522 #ifdef DIAGNOSTIC
2523 	printf("Entering %s with %d boot pages configured\n", __func__, npages);
2524 #endif
2525 
2526 	rw_init(&uma_rwlock, "UMA lock");
2527 
2528 	/* Use bootpages memory for the zone of zones and zone of kegs. */
2529 	m = (uintptr_t)mem;
2530 	zones = (uma_zone_t)m;
2531 	m += roundup(zsize, CACHE_LINE_SIZE);
2532 	kegs = (uma_zone_t)m;
2533 	m += roundup(zsize, CACHE_LINE_SIZE);
2534 	masterkeg = (uma_keg_t)m;
2535 	m += roundup(ksize, CACHE_LINE_SIZE);
2536 	m = roundup(m, PAGE_SIZE);
2537 	npages -= (m - (uintptr_t)mem) / PAGE_SIZE;
2538 	mem = (void *)m;
2539 
2540 	/* "manually" create the initial zone */
2541 	memset(&args, 0, sizeof(args));
2542 	args.name = "UMA Kegs";
2543 	args.size = ksize;
2544 	args.ctor = keg_ctor;
2545 	args.dtor = keg_dtor;
2546 	args.uminit = zero_init;
2547 	args.fini = NULL;
2548 	args.keg = masterkeg;
2549 	args.align = UMA_BOOT_ALIGN - 1;
2550 	args.flags = UMA_ZFLAG_INTERNAL;
2551 	zone_ctor(kegs, zsize, &args, M_WAITOK);
2552 
2553 	bootmem = mem;
2554 	boot_pages = npages;
2555 
2556 	args.name = "UMA Zones";
2557 	args.size = zsize;
2558 	args.ctor = zone_ctor;
2559 	args.dtor = zone_dtor;
2560 	args.uminit = zero_init;
2561 	args.fini = NULL;
2562 	args.keg = NULL;
2563 	args.align = UMA_BOOT_ALIGN - 1;
2564 	args.flags = UMA_ZFLAG_INTERNAL;
2565 	zone_ctor(zones, zsize, &args, M_WAITOK);
2566 
2567 	/* Now make a zone for slab headers */
2568 	slabzone = uma_zcreate("UMA Slabs", sizeof(struct uma_hash_slab),
2569 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
2570 
2571 	hashzone = uma_zcreate("UMA Hash",
2572 	    sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT,
2573 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
2574 
2575 	booted = BOOT_STRAPPED;
2576 }
2577 
2578 void
2579 uma_startup1(void)
2580 {
2581 
2582 #ifdef DIAGNOSTIC
2583 	printf("Entering %s with %d boot pages left\n", __func__, boot_pages);
2584 #endif
2585 	booted = BOOT_PAGEALLOC;
2586 }
2587 
2588 void
2589 uma_startup2(void)
2590 {
2591 
2592 #ifdef DIAGNOSTIC
2593 	printf("Entering %s with %d boot pages left\n", __func__, boot_pages);
2594 #endif
2595 	sx_init(&uma_reclaim_lock, "umareclaim");
2596 	bucket_init();
2597 	booted = BOOT_BUCKETS;
2598 	bucket_enable();
2599 }
2600 
2601 /*
2602  * Initialize our callout handle
2603  *
2604  */
2605 static void
2606 uma_startup3(void)
2607 {
2608 
2609 #ifdef INVARIANTS
2610 	TUNABLE_INT_FETCH("vm.debug.divisor", &dbg_divisor);
2611 	uma_dbg_cnt = counter_u64_alloc(M_WAITOK);
2612 	uma_skip_cnt = counter_u64_alloc(M_WAITOK);
2613 #endif
2614 	zone_foreach(zone_alloc_counters, NULL);
2615 	zone_foreach(zone_alloc_sysctl, NULL);
2616 	callout_init(&uma_callout, 1);
2617 	callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
2618 	booted = BOOT_RUNNING;
2619 }
2620 
2621 static uma_keg_t
2622 uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini,
2623 		int align, uint32_t flags)
2624 {
2625 	struct uma_kctor_args args;
2626 
2627 	args.size = size;
2628 	args.uminit = uminit;
2629 	args.fini = fini;
2630 	args.align = (align == UMA_ALIGN_CACHE) ? uma_align_cache : align;
2631 	args.flags = flags;
2632 	args.zone = zone;
2633 	return (zone_alloc_item(kegs, &args, UMA_ANYDOMAIN, M_WAITOK));
2634 }
2635 
2636 /* Public functions */
2637 /* See uma.h */
2638 void
2639 uma_set_align(int align)
2640 {
2641 
2642 	if (align != UMA_ALIGN_CACHE)
2643 		uma_align_cache = align;
2644 }
2645 
2646 /* See uma.h */
2647 uma_zone_t
2648 uma_zcreate(const char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
2649 		uma_init uminit, uma_fini fini, int align, uint32_t flags)
2650 
2651 {
2652 	struct uma_zctor_args args;
2653 	uma_zone_t res;
2654 	bool locked;
2655 
2656 	KASSERT(powerof2(align + 1), ("invalid zone alignment %d for \"%s\"",
2657 	    align, name));
2658 
2659 	/* Sets all zones to a first-touch domain policy. */
2660 #ifdef UMA_FIRSTTOUCH
2661 	flags |= UMA_ZONE_NUMA;
2662 #endif
2663 
2664 	/* This stuff is essential for the zone ctor */
2665 	memset(&args, 0, sizeof(args));
2666 	args.name = name;
2667 	args.size = size;
2668 	args.ctor = ctor;
2669 	args.dtor = dtor;
2670 	args.uminit = uminit;
2671 	args.fini = fini;
2672 #ifdef  INVARIANTS
2673 	/*
2674 	 * Inject procedures which check for memory use after free if we are
2675 	 * allowed to scramble the memory while it is not allocated.  This
2676 	 * requires that: UMA is actually able to access the memory, no init
2677 	 * or fini procedures, no dependency on the initial value of the
2678 	 * memory, and no (legitimate) use of the memory after free.  Note,
2679 	 * the ctor and dtor do not need to be empty.
2680 	 *
2681 	 * XXX UMA_ZONE_OFFPAGE.
2682 	 */
2683 	if ((!(flags & (UMA_ZONE_ZINIT | UMA_ZONE_NOFREE))) &&
2684 	    uminit == NULL && fini == NULL) {
2685 		args.uminit = trash_init;
2686 		args.fini = trash_fini;
2687 	}
2688 #endif
2689 	args.align = align;
2690 	args.flags = flags;
2691 	args.keg = NULL;
2692 
2693 	if (booted < BOOT_BUCKETS) {
2694 		locked = false;
2695 	} else {
2696 		sx_slock(&uma_reclaim_lock);
2697 		locked = true;
2698 	}
2699 	res = zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK);
2700 	if (locked)
2701 		sx_sunlock(&uma_reclaim_lock);
2702 	return (res);
2703 }
2704 
2705 /* See uma.h */
2706 uma_zone_t
2707 uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
2708 		    uma_init zinit, uma_fini zfini, uma_zone_t master)
2709 {
2710 	struct uma_zctor_args args;
2711 	uma_keg_t keg;
2712 	uma_zone_t res;
2713 	bool locked;
2714 
2715 	keg = master->uz_keg;
2716 	memset(&args, 0, sizeof(args));
2717 	args.name = name;
2718 	args.size = keg->uk_size;
2719 	args.ctor = ctor;
2720 	args.dtor = dtor;
2721 	args.uminit = zinit;
2722 	args.fini = zfini;
2723 	args.align = keg->uk_align;
2724 	args.flags = keg->uk_flags | UMA_ZONE_SECONDARY;
2725 	args.keg = keg;
2726 
2727 	if (booted < BOOT_BUCKETS) {
2728 		locked = false;
2729 	} else {
2730 		sx_slock(&uma_reclaim_lock);
2731 		locked = true;
2732 	}
2733 	/* XXX Attaches only one keg of potentially many. */
2734 	res = zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK);
2735 	if (locked)
2736 		sx_sunlock(&uma_reclaim_lock);
2737 	return (res);
2738 }
2739 
2740 /* See uma.h */
2741 uma_zone_t
2742 uma_zcache_create(char *name, int size, uma_ctor ctor, uma_dtor dtor,
2743 		    uma_init zinit, uma_fini zfini, uma_import zimport,
2744 		    uma_release zrelease, void *arg, int flags)
2745 {
2746 	struct uma_zctor_args args;
2747 
2748 	memset(&args, 0, sizeof(args));
2749 	args.name = name;
2750 	args.size = size;
2751 	args.ctor = ctor;
2752 	args.dtor = dtor;
2753 	args.uminit = zinit;
2754 	args.fini = zfini;
2755 	args.import = zimport;
2756 	args.release = zrelease;
2757 	args.arg = arg;
2758 	args.align = 0;
2759 	args.flags = flags | UMA_ZFLAG_CACHE;
2760 
2761 	return (zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK));
2762 }
2763 
2764 /* See uma.h */
2765 void
2766 uma_zdestroy(uma_zone_t zone)
2767 {
2768 
2769 	sx_slock(&uma_reclaim_lock);
2770 	zone_free_item(zones, zone, NULL, SKIP_NONE);
2771 	sx_sunlock(&uma_reclaim_lock);
2772 }
2773 
2774 void
2775 uma_zwait(uma_zone_t zone)
2776 {
2777 	void *item;
2778 
2779 	item = uma_zalloc_arg(zone, NULL, M_WAITOK);
2780 	uma_zfree(zone, item);
2781 }
2782 
2783 void *
2784 uma_zalloc_pcpu_arg(uma_zone_t zone, void *udata, int flags)
2785 {
2786 	void *item;
2787 #ifdef SMP
2788 	int i;
2789 
2790 	MPASS(zone->uz_flags & UMA_ZONE_PCPU);
2791 #endif
2792 	item = uma_zalloc_arg(zone, udata, flags & ~M_ZERO);
2793 	if (item != NULL && (flags & M_ZERO)) {
2794 #ifdef SMP
2795 		for (i = 0; i <= mp_maxid; i++)
2796 			bzero(zpcpu_get_cpu(item, i), zone->uz_size);
2797 #else
2798 		bzero(item, zone->uz_size);
2799 #endif
2800 	}
2801 	return (item);
2802 }
2803 
2804 /*
2805  * A stub while both regular and pcpu cases are identical.
2806  */
2807 void
2808 uma_zfree_pcpu_arg(uma_zone_t zone, void *item, void *udata)
2809 {
2810 
2811 #ifdef SMP
2812 	MPASS(zone->uz_flags & UMA_ZONE_PCPU);
2813 #endif
2814 	uma_zfree_arg(zone, item, udata);
2815 }
2816 
2817 #ifdef INVARIANTS
2818 #define	UMA_ALWAYS_CTORDTOR	1
2819 #else
2820 #define	UMA_ALWAYS_CTORDTOR	0
2821 #endif
2822 
2823 static void *
2824 item_ctor(uma_zone_t zone, int size, void *udata, int flags, void *item)
2825 {
2826 #ifdef INVARIANTS
2827 	bool skipdbg;
2828 
2829 	skipdbg = uma_dbg_zskip(zone, item);
2830 	if (!skipdbg && (zone->uz_flags & UMA_ZFLAG_TRASH) != 0 &&
2831 	    zone->uz_ctor != trash_ctor)
2832 		trash_ctor(item, size, udata, flags);
2833 #endif
2834 	if (__predict_false(zone->uz_ctor != NULL) &&
2835 	    zone->uz_ctor(item, size, udata, flags) != 0) {
2836 		counter_u64_add(zone->uz_fails, 1);
2837 		zone_free_item(zone, item, udata, SKIP_DTOR | SKIP_CNT);
2838 		return (NULL);
2839 	}
2840 #ifdef INVARIANTS
2841 	if (!skipdbg)
2842 		uma_dbg_alloc(zone, NULL, item);
2843 #endif
2844 	if (flags & M_ZERO)
2845 		bzero(item, size);
2846 
2847 	return (item);
2848 }
2849 
2850 static inline void
2851 item_dtor(uma_zone_t zone, void *item, int size, void *udata,
2852     enum zfreeskip skip)
2853 {
2854 #ifdef INVARIANTS
2855 	bool skipdbg;
2856 
2857 	skipdbg = uma_dbg_zskip(zone, item);
2858 	if (skip == SKIP_NONE && !skipdbg) {
2859 		if ((zone->uz_flags & UMA_ZONE_MALLOC) != 0)
2860 			uma_dbg_free(zone, udata, item);
2861 		else
2862 			uma_dbg_free(zone, NULL, item);
2863 	}
2864 #endif
2865 	if (__predict_true(skip < SKIP_DTOR)) {
2866 		if (zone->uz_dtor != NULL)
2867 			zone->uz_dtor(item, size, udata);
2868 #ifdef INVARIANTS
2869 		if (!skipdbg && (zone->uz_flags & UMA_ZFLAG_TRASH) != 0 &&
2870 		    zone->uz_dtor != trash_dtor)
2871 			trash_dtor(item, size, udata);
2872 #endif
2873 	}
2874 }
2875 
2876 /* See uma.h */
2877 void *
2878 uma_zalloc_arg(uma_zone_t zone, void *udata, int flags)
2879 {
2880 	uma_cache_bucket_t bucket;
2881 	uma_cache_t cache;
2882 	void *item;
2883 	int domain, size, uz_flags;
2884 
2885 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
2886 	random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
2887 
2888 	/* This is the fast path allocation */
2889 	CTR4(KTR_UMA, "uma_zalloc_arg thread %x zone %s(%p) flags %d",
2890 	    curthread, zone->uz_name, zone, flags);
2891 
2892 #ifdef WITNESS
2893 	if (flags & M_WAITOK) {
2894 		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
2895 		    "uma_zalloc_arg: zone \"%s\"", zone->uz_name);
2896 	}
2897 #endif
2898 
2899 #ifdef INVARIANTS
2900 	KASSERT((flags & M_EXEC) == 0, ("uma_zalloc_arg: called with M_EXEC"));
2901 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
2902 	    ("uma_zalloc_arg: called with spinlock or critical section held"));
2903 	if (zone->uz_flags & UMA_ZONE_PCPU)
2904 		KASSERT((flags & M_ZERO) == 0, ("allocating from a pcpu zone "
2905 		    "with M_ZERO passed"));
2906 #endif
2907 
2908 #ifdef DEBUG_MEMGUARD
2909 	if (memguard_cmp_zone(zone)) {
2910 		item = memguard_alloc(zone->uz_size, flags);
2911 		if (item != NULL) {
2912 			if (zone->uz_init != NULL &&
2913 			    zone->uz_init(item, zone->uz_size, flags) != 0)
2914 				return (NULL);
2915 			if (zone->uz_ctor != NULL &&
2916 			    zone->uz_ctor(item, zone->uz_size, udata,
2917 			    flags) != 0) {
2918 				counter_u64_add(zone->uz_fails, 1);
2919 			    	zone->uz_fini(item, zone->uz_size);
2920 				return (NULL);
2921 			}
2922 			return (item);
2923 		}
2924 		/* This is unfortunate but should not be fatal. */
2925 	}
2926 #endif
2927 	/*
2928 	 * If possible, allocate from the per-CPU cache.  There are two
2929 	 * requirements for safe access to the per-CPU cache: (1) the thread
2930 	 * accessing the cache must not be preempted or yield during access,
2931 	 * and (2) the thread must not migrate CPUs without switching which
2932 	 * cache it accesses.  We rely on a critical section to prevent
2933 	 * preemption and migration.  We release the critical section in
2934 	 * order to acquire the zone mutex if we are unable to allocate from
2935 	 * the current cache; when we re-acquire the critical section, we
2936 	 * must detect and handle migration if it has occurred.
2937 	 */
2938 	critical_enter();
2939 	do {
2940 		cache = &zone->uz_cpu[curcpu];
2941 		bucket = &cache->uc_allocbucket;
2942 		size = cache_uz_size(cache);
2943 		uz_flags = cache_uz_flags(cache);
2944 		if (__predict_true(bucket->ucb_cnt != 0)) {
2945 			item = cache_bucket_pop(cache, bucket);
2946 			critical_exit();
2947 			if (__predict_false((uz_flags & UMA_ZFLAG_CTORDTOR) != 0 ||
2948 			    UMA_ALWAYS_CTORDTOR))
2949 				return (item_ctor(zone, size, udata, flags, item));
2950 			if (flags & M_ZERO)
2951 				bzero(item, size);
2952 			return (item);
2953 		}
2954 	} while (cache_alloc(zone, cache, udata, flags));
2955 	critical_exit();
2956 
2957 	/*
2958 	 * We can not get a bucket so try to return a single item.
2959 	 */
2960 	if (uz_flags & UMA_ZONE_NUMA)
2961 		domain = PCPU_GET(domain);
2962 	else
2963 		domain = UMA_ANYDOMAIN;
2964 	return (zone_alloc_item_locked(zone, udata, domain, flags));
2965 }
2966 
2967 /*
2968  * Replenish an alloc bucket and possibly restore an old one.  Called in
2969  * a critical section.  Returns in a critical section.
2970  *
2971  * A false return value indicates failure and returns with the zone lock
2972  * held.  A true return value indicates success and the caller should retry.
2973  */
2974 static __noinline bool
2975 cache_alloc(uma_zone_t zone, uma_cache_t cache, void *udata, int flags)
2976 {
2977 	uma_zone_domain_t zdom;
2978 	uma_bucket_t bucket;
2979 	int domain;
2980 	bool lockfail;
2981 
2982 	CRITICAL_ASSERT(curthread);
2983 
2984 	/*
2985 	 * If we have run out of items in our alloc bucket see
2986 	 * if we can switch with the free bucket.
2987 	 */
2988 	if (cache->uc_freebucket.ucb_cnt != 0) {
2989 		cache_bucket_swap(&cache->uc_freebucket, &cache->uc_allocbucket);
2990 		return (true);
2991 	}
2992 
2993 	/*
2994 	 * Discard any empty allocation bucket while we hold no locks.
2995 	 */
2996 	bucket = cache_bucket_unload_alloc(cache);
2997 	critical_exit();
2998 	if (bucket != NULL)
2999 		bucket_free(zone, bucket, udata);
3000 
3001 	/*
3002 	 * Attempt to retrieve the item from the per-CPU cache has failed, so
3003 	 * we must go back to the zone.  This requires the zone lock, so we
3004 	 * must drop the critical section, then re-acquire it when we go back
3005 	 * to the cache.  Since the critical section is released, we may be
3006 	 * preempted or migrate.  As such, make sure not to maintain any
3007 	 * thread-local state specific to the cache from prior to releasing
3008 	 * the critical section.
3009 	 */
3010 	lockfail = 0;
3011 	if (ZONE_TRYLOCK(zone) == 0) {
3012 		/* Record contention to size the buckets. */
3013 		ZONE_LOCK(zone);
3014 		lockfail = 1;
3015 	}
3016 
3017 	critical_enter();
3018 	/* Short-circuit for zones without buckets and low memory. */
3019 	if (zone->uz_bucket_size == 0 || bucketdisable)
3020 		return (false);
3021 
3022 	cache = &zone->uz_cpu[curcpu];
3023 
3024 	/* See if we lost the race to fill the cache. */
3025 	if (cache->uc_allocbucket.ucb_bucket != NULL) {
3026 		ZONE_UNLOCK(zone);
3027 		return (true);
3028 	}
3029 
3030 	/*
3031 	 * Check the zone's cache of buckets.
3032 	 */
3033 	if (zone->uz_flags & UMA_ZONE_NUMA) {
3034 		domain = PCPU_GET(domain);
3035 		zdom = &zone->uz_domain[domain];
3036 	} else {
3037 		domain = UMA_ANYDOMAIN;
3038 		zdom = &zone->uz_domain[0];
3039 	}
3040 
3041 	if ((bucket = zone_fetch_bucket(zone, zdom)) != NULL) {
3042 		ZONE_UNLOCK(zone);
3043 		KASSERT(bucket->ub_cnt != 0,
3044 		    ("uma_zalloc_arg: Returning an empty bucket."));
3045 		cache_bucket_load_alloc(cache, bucket);
3046 		return (true);
3047 	}
3048 	/* We are no longer associated with this CPU. */
3049 	critical_exit();
3050 
3051 	/*
3052 	 * We bump the uz count when the cache size is insufficient to
3053 	 * handle the working set.
3054 	 */
3055 	if (lockfail && zone->uz_bucket_size < zone->uz_bucket_size_max)
3056 		zone->uz_bucket_size++;
3057 
3058 	/*
3059 	 * Fill a bucket and attempt to use it as the alloc bucket.
3060 	 */
3061 	bucket = zone_alloc_bucket(zone, udata, domain, flags);
3062 	CTR3(KTR_UMA, "uma_zalloc: zone %s(%p) bucket zone returned %p",
3063 	    zone->uz_name, zone, bucket);
3064 	critical_enter();
3065 	if (bucket == NULL)
3066 		return (false);
3067 
3068 	/*
3069 	 * See if we lost the race or were migrated.  Cache the
3070 	 * initialized bucket to make this less likely or claim
3071 	 * the memory directly.
3072 	 */
3073 	cache = &zone->uz_cpu[curcpu];
3074 	if (cache->uc_allocbucket.ucb_bucket == NULL &&
3075 	    ((zone->uz_flags & UMA_ZONE_NUMA) == 0 ||
3076 	    domain == PCPU_GET(domain))) {
3077 		cache_bucket_load_alloc(cache, bucket);
3078 		zdom->uzd_imax += bucket->ub_cnt;
3079 	} else if (zone->uz_bkt_count >= zone->uz_bkt_max) {
3080 		critical_exit();
3081 		ZONE_UNLOCK(zone);
3082 		bucket_drain(zone, bucket);
3083 		bucket_free(zone, bucket, udata);
3084 		critical_enter();
3085 		return (true);
3086 	} else
3087 		zone_put_bucket(zone, zdom, bucket, false);
3088 	ZONE_UNLOCK(zone);
3089 	return (true);
3090 }
3091 
3092 void *
3093 uma_zalloc_domain(uma_zone_t zone, void *udata, int domain, int flags)
3094 {
3095 
3096 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
3097 	random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
3098 
3099 	/* This is the fast path allocation */
3100 	CTR5(KTR_UMA,
3101 	    "uma_zalloc_domain thread %x zone %s(%p) domain %d flags %d",
3102 	    curthread, zone->uz_name, zone, domain, flags);
3103 
3104 	if (flags & M_WAITOK) {
3105 		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
3106 		    "uma_zalloc_domain: zone \"%s\"", zone->uz_name);
3107 	}
3108 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
3109 	    ("uma_zalloc_domain: called with spinlock or critical section held"));
3110 
3111 	return (zone_alloc_item(zone, udata, domain, flags));
3112 }
3113 
3114 /*
3115  * Find a slab with some space.  Prefer slabs that are partially used over those
3116  * that are totally full.  This helps to reduce fragmentation.
3117  *
3118  * If 'rr' is 1, search all domains starting from 'domain'.  Otherwise check
3119  * only 'domain'.
3120  */
3121 static uma_slab_t
3122 keg_first_slab(uma_keg_t keg, int domain, bool rr)
3123 {
3124 	uma_domain_t dom;
3125 	uma_slab_t slab;
3126 	int start;
3127 
3128 	KASSERT(domain >= 0 && domain < vm_ndomains,
3129 	    ("keg_first_slab: domain %d out of range", domain));
3130 	KEG_LOCK_ASSERT(keg);
3131 
3132 	slab = NULL;
3133 	start = domain;
3134 	do {
3135 		dom = &keg->uk_domain[domain];
3136 		if (!LIST_EMPTY(&dom->ud_part_slab))
3137 			return (LIST_FIRST(&dom->ud_part_slab));
3138 		if (!LIST_EMPTY(&dom->ud_free_slab)) {
3139 			slab = LIST_FIRST(&dom->ud_free_slab);
3140 			LIST_REMOVE(slab, us_link);
3141 			LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
3142 			return (slab);
3143 		}
3144 		if (rr)
3145 			domain = (domain + 1) % vm_ndomains;
3146 	} while (domain != start);
3147 
3148 	return (NULL);
3149 }
3150 
3151 static uma_slab_t
3152 keg_fetch_free_slab(uma_keg_t keg, int domain, bool rr, int flags)
3153 {
3154 	uint32_t reserve;
3155 
3156 	KEG_LOCK_ASSERT(keg);
3157 
3158 	reserve = (flags & M_USE_RESERVE) != 0 ? 0 : keg->uk_reserve;
3159 	if (keg->uk_free <= reserve)
3160 		return (NULL);
3161 	return (keg_first_slab(keg, domain, rr));
3162 }
3163 
3164 static uma_slab_t
3165 keg_fetch_slab(uma_keg_t keg, uma_zone_t zone, int rdomain, const int flags)
3166 {
3167 	struct vm_domainset_iter di;
3168 	uma_domain_t dom;
3169 	uma_slab_t slab;
3170 	int aflags, domain;
3171 	bool rr;
3172 
3173 restart:
3174 	KEG_LOCK_ASSERT(keg);
3175 
3176 	/*
3177 	 * Use the keg's policy if upper layers haven't already specified a
3178 	 * domain (as happens with first-touch zones).
3179 	 *
3180 	 * To avoid races we run the iterator with the keg lock held, but that
3181 	 * means that we cannot allow the vm_domainset layer to sleep.  Thus,
3182 	 * clear M_WAITOK and handle low memory conditions locally.
3183 	 */
3184 	rr = rdomain == UMA_ANYDOMAIN;
3185 	if (rr) {
3186 		aflags = (flags & ~M_WAITOK) | M_NOWAIT;
3187 		vm_domainset_iter_policy_ref_init(&di, &keg->uk_dr, &domain,
3188 		    &aflags);
3189 	} else {
3190 		aflags = flags;
3191 		domain = rdomain;
3192 	}
3193 
3194 	for (;;) {
3195 		slab = keg_fetch_free_slab(keg, domain, rr, flags);
3196 		if (slab != NULL)
3197 			return (slab);
3198 
3199 		/*
3200 		 * M_NOVM means don't ask at all!
3201 		 */
3202 		if (flags & M_NOVM)
3203 			break;
3204 
3205 		KASSERT(zone->uz_max_items == 0 ||
3206 		    zone->uz_items <= zone->uz_max_items,
3207 		    ("%s: zone %p overflow", __func__, zone));
3208 
3209 		slab = keg_alloc_slab(keg, zone, domain, flags, aflags);
3210 		/*
3211 		 * If we got a slab here it's safe to mark it partially used
3212 		 * and return.  We assume that the caller is going to remove
3213 		 * at least one item.
3214 		 */
3215 		if (slab) {
3216 			dom = &keg->uk_domain[slab->us_domain];
3217 			LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
3218 			return (slab);
3219 		}
3220 		KEG_LOCK(keg);
3221 		if (!rr && (flags & M_WAITOK) == 0)
3222 			break;
3223 		if (rr && vm_domainset_iter_policy(&di, &domain) != 0) {
3224 			if ((flags & M_WAITOK) != 0) {
3225 				KEG_UNLOCK(keg);
3226 				vm_wait_doms(&keg->uk_dr.dr_policy->ds_mask);
3227 				KEG_LOCK(keg);
3228 				goto restart;
3229 			}
3230 			break;
3231 		}
3232 	}
3233 
3234 	/*
3235 	 * We might not have been able to get a slab but another cpu
3236 	 * could have while we were unlocked.  Check again before we
3237 	 * fail.
3238 	 */
3239 	if ((slab = keg_fetch_free_slab(keg, domain, rr, flags)) != NULL) {
3240 		return (slab);
3241 	}
3242 	return (NULL);
3243 }
3244 
3245 static void *
3246 slab_alloc_item(uma_keg_t keg, uma_slab_t slab)
3247 {
3248 	uma_domain_t dom;
3249 	void *item;
3250 	uint8_t freei;
3251 
3252 	KEG_LOCK_ASSERT(keg);
3253 
3254 	freei = BIT_FFS(keg->uk_ipers, &slab->us_free) - 1;
3255 	BIT_CLR(keg->uk_ipers, freei, &slab->us_free);
3256 	item = slab_item(slab, keg, freei);
3257 	slab->us_freecount--;
3258 	keg->uk_free--;
3259 
3260 	/* Move this slab to the full list */
3261 	if (slab->us_freecount == 0) {
3262 		LIST_REMOVE(slab, us_link);
3263 		dom = &keg->uk_domain[slab->us_domain];
3264 		LIST_INSERT_HEAD(&dom->ud_full_slab, slab, us_link);
3265 	}
3266 
3267 	return (item);
3268 }
3269 
3270 static int
3271 zone_import(void *arg, void **bucket, int max, int domain, int flags)
3272 {
3273 	uma_zone_t zone;
3274 	uma_slab_t slab;
3275 	uma_keg_t keg;
3276 #ifdef NUMA
3277 	int stripe;
3278 #endif
3279 	int i;
3280 
3281 	zone = arg;
3282 	slab = NULL;
3283 	keg = zone->uz_keg;
3284 	KEG_LOCK(keg);
3285 	/* Try to keep the buckets totally full */
3286 	for (i = 0; i < max; ) {
3287 		if ((slab = keg_fetch_slab(keg, zone, domain, flags)) == NULL)
3288 			break;
3289 #ifdef NUMA
3290 		stripe = howmany(max, vm_ndomains);
3291 #endif
3292 		while (slab->us_freecount && i < max) {
3293 			bucket[i++] = slab_alloc_item(keg, slab);
3294 			if (keg->uk_free <= keg->uk_reserve)
3295 				break;
3296 #ifdef NUMA
3297 			/*
3298 			 * If the zone is striped we pick a new slab for every
3299 			 * N allocations.  Eliminating this conditional will
3300 			 * instead pick a new domain for each bucket rather
3301 			 * than stripe within each bucket.  The current option
3302 			 * produces more fragmentation and requires more cpu
3303 			 * time but yields better distribution.
3304 			 */
3305 			if ((zone->uz_flags & UMA_ZONE_NUMA) == 0 &&
3306 			    vm_ndomains > 1 && --stripe == 0)
3307 				break;
3308 #endif
3309 		}
3310 		/* Don't block if we allocated any successfully. */
3311 		flags &= ~M_WAITOK;
3312 		flags |= M_NOWAIT;
3313 	}
3314 	KEG_UNLOCK(keg);
3315 
3316 	return i;
3317 }
3318 
3319 static uma_bucket_t
3320 zone_alloc_bucket(uma_zone_t zone, void *udata, int domain, int flags)
3321 {
3322 	uma_bucket_t bucket;
3323 	int maxbucket, cnt;
3324 
3325 	CTR1(KTR_UMA, "zone_alloc:_bucket domain %d)", domain);
3326 
3327 	/* Avoid allocs targeting empty domains. */
3328 	if (domain != UMA_ANYDOMAIN && VM_DOMAIN_EMPTY(domain))
3329 		domain = UMA_ANYDOMAIN;
3330 
3331 	if (zone->uz_max_items > 0) {
3332 		if (zone->uz_items >= zone->uz_max_items)
3333 			return (false);
3334 		maxbucket = MIN(zone->uz_bucket_size,
3335 		    zone->uz_max_items - zone->uz_items);
3336 		zone->uz_items += maxbucket;
3337 	} else
3338 		maxbucket = zone->uz_bucket_size;
3339 	ZONE_UNLOCK(zone);
3340 
3341 	/* Don't wait for buckets, preserve caller's NOVM setting. */
3342 	bucket = bucket_alloc(zone, udata, M_NOWAIT | (flags & M_NOVM));
3343 	if (bucket == NULL) {
3344 		cnt = 0;
3345 		goto out;
3346 	}
3347 
3348 	bucket->ub_cnt = zone->uz_import(zone->uz_arg, bucket->ub_bucket,
3349 	    MIN(maxbucket, bucket->ub_entries), domain, flags);
3350 
3351 	/*
3352 	 * Initialize the memory if necessary.
3353 	 */
3354 	if (bucket->ub_cnt != 0 && zone->uz_init != NULL) {
3355 		int i;
3356 
3357 		for (i = 0; i < bucket->ub_cnt; i++)
3358 			if (zone->uz_init(bucket->ub_bucket[i], zone->uz_size,
3359 			    flags) != 0)
3360 				break;
3361 		/*
3362 		 * If we couldn't initialize the whole bucket, put the
3363 		 * rest back onto the freelist.
3364 		 */
3365 		if (i != bucket->ub_cnt) {
3366 			zone->uz_release(zone->uz_arg, &bucket->ub_bucket[i],
3367 			    bucket->ub_cnt - i);
3368 #ifdef INVARIANTS
3369 			bzero(&bucket->ub_bucket[i],
3370 			    sizeof(void *) * (bucket->ub_cnt - i));
3371 #endif
3372 			bucket->ub_cnt = i;
3373 		}
3374 	}
3375 
3376 	cnt = bucket->ub_cnt;
3377 	if (bucket->ub_cnt == 0) {
3378 		bucket_free(zone, bucket, udata);
3379 		counter_u64_add(zone->uz_fails, 1);
3380 		bucket = NULL;
3381 	}
3382 out:
3383 	ZONE_LOCK(zone);
3384 	if (zone->uz_max_items > 0 && cnt < maxbucket) {
3385 		MPASS(zone->uz_items >= maxbucket - cnt);
3386 		zone->uz_items -= maxbucket - cnt;
3387 		if (zone->uz_sleepers > 0 &&
3388 		    (cnt == 0 ? zone->uz_items + 1 : zone->uz_items) <
3389 		    zone->uz_max_items)
3390 			wakeup_one(zone);
3391 	}
3392 
3393 	return (bucket);
3394 }
3395 
3396 /*
3397  * Allocates a single item from a zone.
3398  *
3399  * Arguments
3400  *	zone   The zone to alloc for.
3401  *	udata  The data to be passed to the constructor.
3402  *	domain The domain to allocate from or UMA_ANYDOMAIN.
3403  *	flags  M_WAITOK, M_NOWAIT, M_ZERO.
3404  *
3405  * Returns
3406  *	NULL if there is no memory and M_NOWAIT is set
3407  *	An item if successful
3408  */
3409 
3410 static void *
3411 zone_alloc_item(uma_zone_t zone, void *udata, int domain, int flags)
3412 {
3413 
3414 	ZONE_LOCK(zone);
3415 	return (zone_alloc_item_locked(zone, udata, domain, flags));
3416 }
3417 
3418 /*
3419  * Returns with zone unlocked.
3420  */
3421 static void *
3422 zone_alloc_item_locked(uma_zone_t zone, void *udata, int domain, int flags)
3423 {
3424 	void *item;
3425 
3426 	ZONE_LOCK_ASSERT(zone);
3427 
3428 	if (zone->uz_max_items > 0) {
3429 		if (zone->uz_items >= zone->uz_max_items) {
3430 			zone_log_warning(zone);
3431 			zone_maxaction(zone);
3432 			if (flags & M_NOWAIT) {
3433 				ZONE_UNLOCK(zone);
3434 				return (NULL);
3435 			}
3436 			zone->uz_sleeps++;
3437 			zone->uz_sleepers++;
3438 			while (zone->uz_items >= zone->uz_max_items)
3439 				mtx_sleep(zone, zone->uz_lockptr, PVM,
3440 				    "zonelimit", 0);
3441 			zone->uz_sleepers--;
3442 			if (zone->uz_sleepers > 0 &&
3443 			    zone->uz_items + 1 < zone->uz_max_items)
3444 				wakeup_one(zone);
3445 		}
3446 		zone->uz_items++;
3447 	}
3448 	ZONE_UNLOCK(zone);
3449 
3450 	/* Avoid allocs targeting empty domains. */
3451 	if (domain != UMA_ANYDOMAIN && VM_DOMAIN_EMPTY(domain))
3452 		domain = UMA_ANYDOMAIN;
3453 
3454 	if (zone->uz_import(zone->uz_arg, &item, 1, domain, flags) != 1)
3455 		goto fail_cnt;
3456 
3457 	/*
3458 	 * We have to call both the zone's init (not the keg's init)
3459 	 * and the zone's ctor.  This is because the item is going from
3460 	 * a keg slab directly to the user, and the user is expecting it
3461 	 * to be both zone-init'd as well as zone-ctor'd.
3462 	 */
3463 	if (zone->uz_init != NULL) {
3464 		if (zone->uz_init(item, zone->uz_size, flags) != 0) {
3465 			zone_free_item(zone, item, udata, SKIP_FINI | SKIP_CNT);
3466 			goto fail_cnt;
3467 		}
3468 	}
3469 	item = item_ctor(zone, zone->uz_size, udata, flags, item);
3470 	if (item == NULL)
3471 		goto fail;
3472 
3473 	counter_u64_add(zone->uz_allocs, 1);
3474 	CTR3(KTR_UMA, "zone_alloc_item item %p from %s(%p)", item,
3475 	    zone->uz_name, zone);
3476 
3477 	return (item);
3478 
3479 fail_cnt:
3480 	counter_u64_add(zone->uz_fails, 1);
3481 fail:
3482 	if (zone->uz_max_items > 0) {
3483 		ZONE_LOCK(zone);
3484 		/* XXX Decrement without wakeup */
3485 		zone->uz_items--;
3486 		ZONE_UNLOCK(zone);
3487 	}
3488 	CTR2(KTR_UMA, "zone_alloc_item failed from %s(%p)",
3489 	    zone->uz_name, zone);
3490 	return (NULL);
3491 }
3492 
3493 /* See uma.h */
3494 void
3495 uma_zfree_arg(uma_zone_t zone, void *item, void *udata)
3496 {
3497 	uma_cache_t cache;
3498 	uma_cache_bucket_t bucket;
3499 	int domain, itemdomain, uz_flags;
3500 
3501 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
3502 	random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
3503 
3504 	CTR2(KTR_UMA, "uma_zfree_arg thread %x zone %s", curthread,
3505 	    zone->uz_name);
3506 
3507 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
3508 	    ("uma_zfree_arg: called with spinlock or critical section held"));
3509 
3510         /* uma_zfree(..., NULL) does nothing, to match free(9). */
3511         if (item == NULL)
3512                 return;
3513 #ifdef DEBUG_MEMGUARD
3514 	if (is_memguard_addr(item)) {
3515 		if (zone->uz_dtor != NULL)
3516 			zone->uz_dtor(item, zone->uz_size, udata);
3517 		if (zone->uz_fini != NULL)
3518 			zone->uz_fini(item, zone->uz_size);
3519 		memguard_free(item);
3520 		return;
3521 	}
3522 #endif
3523 
3524 	/*
3525 	 * We are accessing the per-cpu cache without a critical section to
3526 	 * fetch size and flags.  This is acceptable, if we are preempted we
3527 	 * will simply read another cpu's line.
3528 	 */
3529 	cache = &zone->uz_cpu[curcpu];
3530 	uz_flags = cache_uz_flags(cache);
3531 	if (__predict_false((uz_flags & UMA_ZFLAG_CTORDTOR) != 0 ||
3532 	    UMA_ALWAYS_CTORDTOR))
3533 		item_dtor(zone, item, cache_uz_size(cache), udata, SKIP_NONE);
3534 
3535 	/*
3536 	 * The race here is acceptable.  If we miss it we'll just have to wait
3537 	 * a little longer for the limits to be reset.
3538 	 */
3539 	if (__predict_false(uz_flags & UMA_ZFLAG_LIMIT)) {
3540 		if (zone->uz_sleepers > 0)
3541 			goto zfree_item;
3542 	}
3543 
3544 	/*
3545 	 * If possible, free to the per-CPU cache.  There are two
3546 	 * requirements for safe access to the per-CPU cache: (1) the thread
3547 	 * accessing the cache must not be preempted or yield during access,
3548 	 * and (2) the thread must not migrate CPUs without switching which
3549 	 * cache it accesses.  We rely on a critical section to prevent
3550 	 * preemption and migration.  We release the critical section in
3551 	 * order to acquire the zone mutex if we are unable to free to the
3552 	 * current cache; when we re-acquire the critical section, we must
3553 	 * detect and handle migration if it has occurred.
3554 	 */
3555 	domain = itemdomain = 0;
3556 	critical_enter();
3557 	do {
3558 		cache = &zone->uz_cpu[curcpu];
3559 		bucket = &cache->uc_allocbucket;
3560 #ifdef UMA_XDOMAIN
3561 		if ((uz_flags & UMA_ZONE_NUMA) != 0) {
3562 			itemdomain = _vm_phys_domain(pmap_kextract((vm_offset_t)item));
3563 			domain = PCPU_GET(domain);
3564 		}
3565 		if ((uz_flags & UMA_ZONE_NUMA) != 0 && domain != itemdomain) {
3566 			bucket = &cache->uc_crossbucket;
3567 		} else
3568 #endif
3569 
3570 		/*
3571 		 * Try to free into the allocbucket first to give LIFO ordering
3572 		 * for cache-hot datastructures.  Spill over into the freebucket
3573 		 * if necessary.  Alloc will swap them if one runs dry.
3574 		 */
3575 		if (__predict_false(bucket->ucb_cnt >= bucket->ucb_entries))
3576 			bucket = &cache->uc_freebucket;
3577 		if (__predict_true(bucket->ucb_cnt < bucket->ucb_entries)) {
3578 			cache_bucket_push(cache, bucket, item);
3579 			critical_exit();
3580 			return;
3581 		}
3582 	} while (cache_free(zone, cache, udata, item, itemdomain));
3583 	critical_exit();
3584 
3585 	/*
3586 	 * If nothing else caught this, we'll just do an internal free.
3587 	 */
3588 zfree_item:
3589 	zone_free_item(zone, item, udata, SKIP_DTOR);
3590 }
3591 
3592 static void
3593 zone_free_bucket(uma_zone_t zone, uma_bucket_t bucket, void *udata,
3594     int domain, int itemdomain)
3595 {
3596 	uma_zone_domain_t zdom;
3597 
3598 #ifdef UMA_XDOMAIN
3599 	/*
3600 	 * Buckets coming from the wrong domain will be entirely for the
3601 	 * only other domain on two domain systems.  In this case we can
3602 	 * simply cache them.  Otherwise we need to sort them back to
3603 	 * correct domains by freeing the contents to the slab layer.
3604 	 */
3605 	if (domain != itemdomain && vm_ndomains > 2) {
3606 		CTR3(KTR_UMA,
3607 		    "uma_zfree: zone %s(%p) draining cross bucket %p",
3608 		    zone->uz_name, zone, bucket);
3609 		bucket_drain(zone, bucket);
3610 		bucket_free(zone, bucket, udata);
3611 		return;
3612 	}
3613 #endif
3614 	/*
3615 	 * Attempt to save the bucket in the zone's domain bucket cache.
3616 	 *
3617 	 * We bump the uz count when the cache size is insufficient to
3618 	 * handle the working set.
3619 	 */
3620 	if (ZONE_TRYLOCK(zone) == 0) {
3621 		/* Record contention to size the buckets. */
3622 		ZONE_LOCK(zone);
3623 		if (zone->uz_bucket_size < zone->uz_bucket_size_max)
3624 			zone->uz_bucket_size++;
3625 	}
3626 
3627 	CTR3(KTR_UMA,
3628 	    "uma_zfree: zone %s(%p) putting bucket %p on free list",
3629 	    zone->uz_name, zone, bucket);
3630 	/* ub_cnt is pointing to the last free item */
3631 	KASSERT(bucket->ub_cnt == bucket->ub_entries,
3632 	    ("uma_zfree: Attempting to insert partial  bucket onto the full list.\n"));
3633 	if (zone->uz_bkt_count >= zone->uz_bkt_max) {
3634 		ZONE_UNLOCK(zone);
3635 		bucket_drain(zone, bucket);
3636 		bucket_free(zone, bucket, udata);
3637 	} else {
3638 		zdom = &zone->uz_domain[itemdomain];
3639 		zone_put_bucket(zone, zdom, bucket, true);
3640 		ZONE_UNLOCK(zone);
3641 	}
3642 }
3643 
3644 /*
3645  * Populate a free or cross bucket for the current cpu cache.  Free any
3646  * existing full bucket either to the zone cache or back to the slab layer.
3647  *
3648  * Enters and returns in a critical section.  false return indicates that
3649  * we can not satisfy this free in the cache layer.  true indicates that
3650  * the caller should retry.
3651  */
3652 static __noinline bool
3653 cache_free(uma_zone_t zone, uma_cache_t cache, void *udata, void *item,
3654     int itemdomain)
3655 {
3656 	uma_bucket_t bucket;
3657 	int domain;
3658 
3659 	CRITICAL_ASSERT(curthread);
3660 
3661 	if (zone->uz_bucket_size == 0 || bucketdisable)
3662 		return false;
3663 
3664 	cache = &zone->uz_cpu[curcpu];
3665 
3666 	/*
3667 	 * NUMA domains need to free to the correct zdom.  When XDOMAIN
3668 	 * is enabled this is the zdom of the item and the bucket may be
3669 	 * the cross bucket if they do not match.
3670 	 */
3671 	if ((zone->uz_flags & UMA_ZONE_NUMA) != 0)
3672 #ifdef UMA_XDOMAIN
3673 		domain = PCPU_GET(domain);
3674 #else
3675 		itemdomain = domain = PCPU_GET(domain);
3676 #endif
3677 	else
3678 		itemdomain = domain = 0;
3679 #ifdef UMA_XDOMAIN
3680 	if (domain != itemdomain) {
3681 		bucket = cache_bucket_unload_cross(cache);
3682 		if (bucket != NULL)
3683 			atomic_add_64(&zone->uz_xdomain, bucket->ub_cnt);
3684 	} else
3685 #endif
3686 		bucket = cache_bucket_unload_free(cache);
3687 
3688 
3689 	/* We are no longer associated with this CPU. */
3690 	critical_exit();
3691 
3692 	if (bucket != NULL)
3693 		zone_free_bucket(zone, bucket, udata, domain, itemdomain);
3694 
3695 	bucket = bucket_alloc(zone, udata, M_NOWAIT);
3696 	CTR3(KTR_UMA, "uma_zfree: zone %s(%p) allocated bucket %p",
3697 	    zone->uz_name, zone, bucket);
3698 	critical_enter();
3699 	if (bucket == NULL)
3700 		return (false);
3701 	cache = &zone->uz_cpu[curcpu];
3702 #ifdef UMA_XDOMAIN
3703 	/*
3704 	 * Check to see if we should be populating the cross bucket.  If it
3705 	 * is already populated we will fall through and attempt to populate
3706 	 * the free bucket.
3707 	 */
3708 	if ((zone->uz_flags & UMA_ZONE_NUMA) != 0) {
3709 		domain = PCPU_GET(domain);
3710 		if (domain != itemdomain &&
3711 		    cache->uc_crossbucket.ucb_bucket == NULL) {
3712 			cache_bucket_load_cross(cache, bucket);
3713 			return (true);
3714 		}
3715 	}
3716 #endif
3717 	/*
3718 	 * We may have lost the race to fill the bucket or switched CPUs.
3719 	 */
3720 	if (cache->uc_freebucket.ucb_bucket != NULL) {
3721 		critical_exit();
3722 		bucket_free(zone, bucket, udata);
3723 		critical_enter();
3724 	} else
3725 		cache_bucket_load_free(cache, bucket);
3726 
3727 	return (true);
3728 }
3729 
3730 void
3731 uma_zfree_domain(uma_zone_t zone, void *item, void *udata)
3732 {
3733 
3734 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
3735 	random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
3736 
3737 	CTR2(KTR_UMA, "uma_zfree_domain thread %x zone %s", curthread,
3738 	    zone->uz_name);
3739 
3740 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
3741 	    ("uma_zfree_domain: called with spinlock or critical section held"));
3742 
3743         /* uma_zfree(..., NULL) does nothing, to match free(9). */
3744         if (item == NULL)
3745                 return;
3746 	zone_free_item(zone, item, udata, SKIP_NONE);
3747 }
3748 
3749 static void
3750 slab_free_item(uma_zone_t zone, uma_slab_t slab, void *item)
3751 {
3752 	uma_keg_t keg;
3753 	uma_domain_t dom;
3754 	uint8_t freei;
3755 
3756 	keg = zone->uz_keg;
3757 	MPASS(zone->uz_lockptr == &keg->uk_lock);
3758 	KEG_LOCK_ASSERT(keg);
3759 
3760 	dom = &keg->uk_domain[slab->us_domain];
3761 
3762 	/* Do we need to remove from any lists? */
3763 	if (slab->us_freecount+1 == keg->uk_ipers) {
3764 		LIST_REMOVE(slab, us_link);
3765 		LIST_INSERT_HEAD(&dom->ud_free_slab, slab, us_link);
3766 	} else if (slab->us_freecount == 0) {
3767 		LIST_REMOVE(slab, us_link);
3768 		LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
3769 	}
3770 
3771 	/* Slab management. */
3772 	freei = slab_item_index(slab, keg, item);
3773 	BIT_SET(keg->uk_ipers, freei, &slab->us_free);
3774 	slab->us_freecount++;
3775 
3776 	/* Keg statistics. */
3777 	keg->uk_free++;
3778 }
3779 
3780 static void
3781 zone_release(void *arg, void **bucket, int cnt)
3782 {
3783 	uma_zone_t zone;
3784 	void *item;
3785 	uma_slab_t slab;
3786 	uma_keg_t keg;
3787 	uint8_t *mem;
3788 	int i;
3789 
3790 	zone = arg;
3791 	keg = zone->uz_keg;
3792 	KEG_LOCK(keg);
3793 	for (i = 0; i < cnt; i++) {
3794 		item = bucket[i];
3795 		if (!(zone->uz_flags & UMA_ZONE_VTOSLAB)) {
3796 			mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
3797 			if (zone->uz_flags & UMA_ZONE_HASH) {
3798 				slab = hash_sfind(&keg->uk_hash, mem);
3799 			} else {
3800 				mem += keg->uk_pgoff;
3801 				slab = (uma_slab_t)mem;
3802 			}
3803 		} else
3804 			slab = vtoslab((vm_offset_t)item);
3805 		slab_free_item(zone, slab, item);
3806 	}
3807 	KEG_UNLOCK(keg);
3808 }
3809 
3810 /*
3811  * Frees a single item to any zone.
3812  *
3813  * Arguments:
3814  *	zone   The zone to free to
3815  *	item   The item we're freeing
3816  *	udata  User supplied data for the dtor
3817  *	skip   Skip dtors and finis
3818  */
3819 static void
3820 zone_free_item(uma_zone_t zone, void *item, void *udata, enum zfreeskip skip)
3821 {
3822 
3823 	item_dtor(zone, item, zone->uz_size, udata, skip);
3824 
3825 	if (skip < SKIP_FINI && zone->uz_fini)
3826 		zone->uz_fini(item, zone->uz_size);
3827 
3828 	zone->uz_release(zone->uz_arg, &item, 1);
3829 
3830 	if (skip & SKIP_CNT)
3831 		return;
3832 
3833 	counter_u64_add(zone->uz_frees, 1);
3834 
3835 	if (zone->uz_max_items > 0) {
3836 		ZONE_LOCK(zone);
3837 		zone->uz_items--;
3838 		if (zone->uz_sleepers > 0 &&
3839 		    zone->uz_items < zone->uz_max_items)
3840 			wakeup_one(zone);
3841 		ZONE_UNLOCK(zone);
3842 	}
3843 }
3844 
3845 /* See uma.h */
3846 int
3847 uma_zone_set_max(uma_zone_t zone, int nitems)
3848 {
3849 	struct uma_bucket_zone *ubz;
3850 	int count;
3851 
3852 	ZONE_LOCK(zone);
3853 	ubz = bucket_zone_max(zone, nitems);
3854 	count = ubz != NULL ? ubz->ubz_entries : 0;
3855 	zone->uz_bucket_size_max = zone->uz_bucket_size = count;
3856 	if (zone->uz_bucket_size_min > zone->uz_bucket_size_max)
3857 		zone->uz_bucket_size_min = zone->uz_bucket_size_max;
3858 	zone->uz_max_items = nitems;
3859 	zone->uz_flags |= UMA_ZFLAG_LIMIT;
3860 	zone_update_caches(zone);
3861 	ZONE_UNLOCK(zone);
3862 
3863 	return (nitems);
3864 }
3865 
3866 /* See uma.h */
3867 void
3868 uma_zone_set_maxcache(uma_zone_t zone, int nitems)
3869 {
3870 	struct uma_bucket_zone *ubz;
3871 	int bpcpu;
3872 
3873 	ZONE_LOCK(zone);
3874 	ubz = bucket_zone_max(zone, nitems);
3875 	if (ubz != NULL) {
3876 		bpcpu = 2;
3877 #ifdef UMA_XDOMAIN
3878 		if ((zone->uz_flags & UMA_ZONE_NUMA) != 0)
3879 			/* Count the cross-domain bucket. */
3880 			bpcpu++;
3881 #endif
3882 		nitems -= ubz->ubz_entries * bpcpu * mp_ncpus;
3883 		zone->uz_bucket_size_max = ubz->ubz_entries;
3884 	} else {
3885 		zone->uz_bucket_size_max = zone->uz_bucket_size = 0;
3886 	}
3887 	if (zone->uz_bucket_size_min > zone->uz_bucket_size_max)
3888 		zone->uz_bucket_size_min = zone->uz_bucket_size_max;
3889 	zone->uz_bkt_max = nitems;
3890 	ZONE_UNLOCK(zone);
3891 }
3892 
3893 /* See uma.h */
3894 int
3895 uma_zone_get_max(uma_zone_t zone)
3896 {
3897 	int nitems;
3898 
3899 	ZONE_LOCK(zone);
3900 	nitems = zone->uz_max_items;
3901 	ZONE_UNLOCK(zone);
3902 
3903 	return (nitems);
3904 }
3905 
3906 /* See uma.h */
3907 void
3908 uma_zone_set_warning(uma_zone_t zone, const char *warning)
3909 {
3910 
3911 	ZONE_LOCK(zone);
3912 	zone->uz_warning = warning;
3913 	ZONE_UNLOCK(zone);
3914 }
3915 
3916 /* See uma.h */
3917 void
3918 uma_zone_set_maxaction(uma_zone_t zone, uma_maxaction_t maxaction)
3919 {
3920 
3921 	ZONE_LOCK(zone);
3922 	TASK_INIT(&zone->uz_maxaction, 0, (task_fn_t *)maxaction, zone);
3923 	ZONE_UNLOCK(zone);
3924 }
3925 
3926 /* See uma.h */
3927 int
3928 uma_zone_get_cur(uma_zone_t zone)
3929 {
3930 	int64_t nitems;
3931 	u_int i;
3932 
3933 	ZONE_LOCK(zone);
3934 	nitems = counter_u64_fetch(zone->uz_allocs) -
3935 	    counter_u64_fetch(zone->uz_frees);
3936 	if ((zone->uz_flags & UMA_ZFLAG_INTERNAL) == 0) {
3937 		CPU_FOREACH(i) {
3938 			/*
3939 			 * See the comment in uma_vm_zone_stats() regarding
3940 			 * the safety of accessing the per-cpu caches. With
3941 			 * the zone lock held, it is safe, but can potentially
3942 			 * result in stale data.
3943 			 */
3944 			nitems += zone->uz_cpu[i].uc_allocs -
3945 			    zone->uz_cpu[i].uc_frees;
3946 		}
3947 	}
3948 	ZONE_UNLOCK(zone);
3949 
3950 	return (nitems < 0 ? 0 : nitems);
3951 }
3952 
3953 static uint64_t
3954 uma_zone_get_allocs(uma_zone_t zone)
3955 {
3956 	uint64_t nitems;
3957 	u_int i;
3958 
3959 	ZONE_LOCK(zone);
3960 	nitems = counter_u64_fetch(zone->uz_allocs);
3961 	if ((zone->uz_flags & UMA_ZFLAG_INTERNAL) == 0) {
3962 		CPU_FOREACH(i) {
3963 			/*
3964 			 * See the comment in uma_vm_zone_stats() regarding
3965 			 * the safety of accessing the per-cpu caches. With
3966 			 * the zone lock held, it is safe, but can potentially
3967 			 * result in stale data.
3968 			 */
3969 			nitems += zone->uz_cpu[i].uc_allocs;
3970 		}
3971 	}
3972 	ZONE_UNLOCK(zone);
3973 
3974 	return (nitems);
3975 }
3976 
3977 static uint64_t
3978 uma_zone_get_frees(uma_zone_t zone)
3979 {
3980 	uint64_t nitems;
3981 	u_int i;
3982 
3983 	ZONE_LOCK(zone);
3984 	nitems = counter_u64_fetch(zone->uz_frees);
3985 	if ((zone->uz_flags & UMA_ZFLAG_INTERNAL) == 0) {
3986 		CPU_FOREACH(i) {
3987 			/*
3988 			 * See the comment in uma_vm_zone_stats() regarding
3989 			 * the safety of accessing the per-cpu caches. With
3990 			 * the zone lock held, it is safe, but can potentially
3991 			 * result in stale data.
3992 			 */
3993 			nitems += zone->uz_cpu[i].uc_frees;
3994 		}
3995 	}
3996 	ZONE_UNLOCK(zone);
3997 
3998 	return (nitems);
3999 }
4000 
4001 /* See uma.h */
4002 void
4003 uma_zone_set_init(uma_zone_t zone, uma_init uminit)
4004 {
4005 	uma_keg_t keg;
4006 
4007 	KEG_GET(zone, keg);
4008 	KEG_LOCK(keg);
4009 	KASSERT(keg->uk_pages == 0,
4010 	    ("uma_zone_set_init on non-empty keg"));
4011 	keg->uk_init = uminit;
4012 	KEG_UNLOCK(keg);
4013 }
4014 
4015 /* See uma.h */
4016 void
4017 uma_zone_set_fini(uma_zone_t zone, uma_fini fini)
4018 {
4019 	uma_keg_t keg;
4020 
4021 	KEG_GET(zone, keg);
4022 	KEG_LOCK(keg);
4023 	KASSERT(keg->uk_pages == 0,
4024 	    ("uma_zone_set_fini on non-empty keg"));
4025 	keg->uk_fini = fini;
4026 	KEG_UNLOCK(keg);
4027 }
4028 
4029 /* See uma.h */
4030 void
4031 uma_zone_set_zinit(uma_zone_t zone, uma_init zinit)
4032 {
4033 
4034 	ZONE_LOCK(zone);
4035 	KASSERT(zone->uz_keg->uk_pages == 0,
4036 	    ("uma_zone_set_zinit on non-empty keg"));
4037 	zone->uz_init = zinit;
4038 	ZONE_UNLOCK(zone);
4039 }
4040 
4041 /* See uma.h */
4042 void
4043 uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini)
4044 {
4045 
4046 	ZONE_LOCK(zone);
4047 	KASSERT(zone->uz_keg->uk_pages == 0,
4048 	    ("uma_zone_set_zfini on non-empty keg"));
4049 	zone->uz_fini = zfini;
4050 	ZONE_UNLOCK(zone);
4051 }
4052 
4053 /* See uma.h */
4054 /* XXX uk_freef is not actually used with the zone locked */
4055 void
4056 uma_zone_set_freef(uma_zone_t zone, uma_free freef)
4057 {
4058 	uma_keg_t keg;
4059 
4060 	KEG_GET(zone, keg);
4061 	KASSERT(keg != NULL, ("uma_zone_set_freef: Invalid zone type"));
4062 	KEG_LOCK(keg);
4063 	keg->uk_freef = freef;
4064 	KEG_UNLOCK(keg);
4065 }
4066 
4067 /* See uma.h */
4068 /* XXX uk_allocf is not actually used with the zone locked */
4069 void
4070 uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf)
4071 {
4072 	uma_keg_t keg;
4073 
4074 	KEG_GET(zone, keg);
4075 	KEG_LOCK(keg);
4076 	keg->uk_allocf = allocf;
4077 	KEG_UNLOCK(keg);
4078 }
4079 
4080 /* See uma.h */
4081 void
4082 uma_zone_reserve(uma_zone_t zone, int items)
4083 {
4084 	uma_keg_t keg;
4085 
4086 	KEG_GET(zone, keg);
4087 	KEG_LOCK(keg);
4088 	keg->uk_reserve = items;
4089 	KEG_UNLOCK(keg);
4090 }
4091 
4092 /* See uma.h */
4093 int
4094 uma_zone_reserve_kva(uma_zone_t zone, int count)
4095 {
4096 	uma_keg_t keg;
4097 	vm_offset_t kva;
4098 	u_int pages;
4099 
4100 	KEG_GET(zone, keg);
4101 
4102 	pages = count / keg->uk_ipers;
4103 	if (pages * keg->uk_ipers < count)
4104 		pages++;
4105 	pages *= keg->uk_ppera;
4106 
4107 #ifdef UMA_MD_SMALL_ALLOC
4108 	if (keg->uk_ppera > 1) {
4109 #else
4110 	if (1) {
4111 #endif
4112 		kva = kva_alloc((vm_size_t)pages * PAGE_SIZE);
4113 		if (kva == 0)
4114 			return (0);
4115 	} else
4116 		kva = 0;
4117 
4118 	ZONE_LOCK(zone);
4119 	MPASS(keg->uk_kva == 0);
4120 	keg->uk_kva = kva;
4121 	keg->uk_offset = 0;
4122 	zone->uz_max_items = pages * keg->uk_ipers;
4123 #ifdef UMA_MD_SMALL_ALLOC
4124 	keg->uk_allocf = (keg->uk_ppera > 1) ? noobj_alloc : uma_small_alloc;
4125 #else
4126 	keg->uk_allocf = noobj_alloc;
4127 #endif
4128 	keg->uk_flags |= UMA_ZFLAG_LIMIT | UMA_ZONE_NOFREE;
4129 	zone->uz_flags |= UMA_ZFLAG_LIMIT | UMA_ZONE_NOFREE;
4130 	zone_update_caches(zone);
4131 	ZONE_UNLOCK(zone);
4132 
4133 	return (1);
4134 }
4135 
4136 /* See uma.h */
4137 void
4138 uma_prealloc(uma_zone_t zone, int items)
4139 {
4140 	struct vm_domainset_iter di;
4141 	uma_domain_t dom;
4142 	uma_slab_t slab;
4143 	uma_keg_t keg;
4144 	int aflags, domain, slabs;
4145 
4146 	KEG_GET(zone, keg);
4147 	KEG_LOCK(keg);
4148 	slabs = items / keg->uk_ipers;
4149 	if (slabs * keg->uk_ipers < items)
4150 		slabs++;
4151 	while (slabs-- > 0) {
4152 		aflags = M_NOWAIT;
4153 		vm_domainset_iter_policy_ref_init(&di, &keg->uk_dr, &domain,
4154 		    &aflags);
4155 		for (;;) {
4156 			slab = keg_alloc_slab(keg, zone, domain, M_WAITOK,
4157 			    aflags);
4158 			if (slab != NULL) {
4159 				dom = &keg->uk_domain[slab->us_domain];
4160 				LIST_INSERT_HEAD(&dom->ud_free_slab, slab,
4161 				    us_link);
4162 				break;
4163 			}
4164 			KEG_LOCK(keg);
4165 			if (vm_domainset_iter_policy(&di, &domain) != 0) {
4166 				KEG_UNLOCK(keg);
4167 				vm_wait_doms(&keg->uk_dr.dr_policy->ds_mask);
4168 				KEG_LOCK(keg);
4169 			}
4170 		}
4171 	}
4172 	KEG_UNLOCK(keg);
4173 }
4174 
4175 /* See uma.h */
4176 void
4177 uma_reclaim(int req)
4178 {
4179 
4180 	CTR0(KTR_UMA, "UMA: vm asked us to release pages!");
4181 	sx_xlock(&uma_reclaim_lock);
4182 	bucket_enable();
4183 
4184 	switch (req) {
4185 	case UMA_RECLAIM_TRIM:
4186 		zone_foreach(zone_trim, NULL);
4187 		break;
4188 	case UMA_RECLAIM_DRAIN:
4189 	case UMA_RECLAIM_DRAIN_CPU:
4190 		zone_foreach(zone_drain, NULL);
4191 		if (req == UMA_RECLAIM_DRAIN_CPU) {
4192 			pcpu_cache_drain_safe(NULL);
4193 			zone_foreach(zone_drain, NULL);
4194 		}
4195 		break;
4196 	default:
4197 		panic("unhandled reclamation request %d", req);
4198 	}
4199 
4200 	/*
4201 	 * Some slabs may have been freed but this zone will be visited early
4202 	 * we visit again so that we can free pages that are empty once other
4203 	 * zones are drained.  We have to do the same for buckets.
4204 	 */
4205 	zone_drain(slabzone, NULL);
4206 	bucket_zone_drain();
4207 	sx_xunlock(&uma_reclaim_lock);
4208 }
4209 
4210 static volatile int uma_reclaim_needed;
4211 
4212 void
4213 uma_reclaim_wakeup(void)
4214 {
4215 
4216 	if (atomic_fetchadd_int(&uma_reclaim_needed, 1) == 0)
4217 		wakeup(uma_reclaim);
4218 }
4219 
4220 void
4221 uma_reclaim_worker(void *arg __unused)
4222 {
4223 
4224 	for (;;) {
4225 		sx_xlock(&uma_reclaim_lock);
4226 		while (atomic_load_int(&uma_reclaim_needed) == 0)
4227 			sx_sleep(uma_reclaim, &uma_reclaim_lock, PVM, "umarcl",
4228 			    hz);
4229 		sx_xunlock(&uma_reclaim_lock);
4230 		EVENTHANDLER_INVOKE(vm_lowmem, VM_LOW_KMEM);
4231 		uma_reclaim(UMA_RECLAIM_DRAIN_CPU);
4232 		atomic_store_int(&uma_reclaim_needed, 0);
4233 		/* Don't fire more than once per-second. */
4234 		pause("umarclslp", hz);
4235 	}
4236 }
4237 
4238 /* See uma.h */
4239 void
4240 uma_zone_reclaim(uma_zone_t zone, int req)
4241 {
4242 
4243 	switch (req) {
4244 	case UMA_RECLAIM_TRIM:
4245 		zone_trim(zone, NULL);
4246 		break;
4247 	case UMA_RECLAIM_DRAIN:
4248 		zone_drain(zone, NULL);
4249 		break;
4250 	case UMA_RECLAIM_DRAIN_CPU:
4251 		pcpu_cache_drain_safe(zone);
4252 		zone_drain(zone, NULL);
4253 		break;
4254 	default:
4255 		panic("unhandled reclamation request %d", req);
4256 	}
4257 }
4258 
4259 /* See uma.h */
4260 int
4261 uma_zone_exhausted(uma_zone_t zone)
4262 {
4263 	int full;
4264 
4265 	ZONE_LOCK(zone);
4266 	full = zone->uz_sleepers > 0;
4267 	ZONE_UNLOCK(zone);
4268 	return (full);
4269 }
4270 
4271 int
4272 uma_zone_exhausted_nolock(uma_zone_t zone)
4273 {
4274 	return (zone->uz_sleepers > 0);
4275 }
4276 
4277 unsigned long
4278 uma_limit(void)
4279 {
4280 
4281 	return (uma_kmem_limit);
4282 }
4283 
4284 void
4285 uma_set_limit(unsigned long limit)
4286 {
4287 
4288 	uma_kmem_limit = limit;
4289 }
4290 
4291 unsigned long
4292 uma_size(void)
4293 {
4294 
4295 	return (atomic_load_long(&uma_kmem_total));
4296 }
4297 
4298 long
4299 uma_avail(void)
4300 {
4301 
4302 	return (uma_kmem_limit - uma_size());
4303 }
4304 
4305 #ifdef DDB
4306 /*
4307  * Generate statistics across both the zone and its per-cpu cache's.  Return
4308  * desired statistics if the pointer is non-NULL for that statistic.
4309  *
4310  * Note: does not update the zone statistics, as it can't safely clear the
4311  * per-CPU cache statistic.
4312  *
4313  */
4314 static void
4315 uma_zone_sumstat(uma_zone_t z, long *cachefreep, uint64_t *allocsp,
4316     uint64_t *freesp, uint64_t *sleepsp, uint64_t *xdomainp)
4317 {
4318 	uma_cache_t cache;
4319 	uint64_t allocs, frees, sleeps, xdomain;
4320 	int cachefree, cpu;
4321 
4322 	allocs = frees = sleeps = xdomain = 0;
4323 	cachefree = 0;
4324 	CPU_FOREACH(cpu) {
4325 		cache = &z->uz_cpu[cpu];
4326 		cachefree += cache->uc_allocbucket.ucb_cnt;
4327 		cachefree += cache->uc_freebucket.ucb_cnt;
4328 		xdomain += cache->uc_crossbucket.ucb_cnt;
4329 		cachefree += cache->uc_crossbucket.ucb_cnt;
4330 		allocs += cache->uc_allocs;
4331 		frees += cache->uc_frees;
4332 	}
4333 	allocs += counter_u64_fetch(z->uz_allocs);
4334 	frees += counter_u64_fetch(z->uz_frees);
4335 	sleeps += z->uz_sleeps;
4336 	xdomain += z->uz_xdomain;
4337 	if (cachefreep != NULL)
4338 		*cachefreep = cachefree;
4339 	if (allocsp != NULL)
4340 		*allocsp = allocs;
4341 	if (freesp != NULL)
4342 		*freesp = frees;
4343 	if (sleepsp != NULL)
4344 		*sleepsp = sleeps;
4345 	if (xdomainp != NULL)
4346 		*xdomainp = xdomain;
4347 }
4348 #endif /* DDB */
4349 
4350 static int
4351 sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS)
4352 {
4353 	uma_keg_t kz;
4354 	uma_zone_t z;
4355 	int count;
4356 
4357 	count = 0;
4358 	rw_rlock(&uma_rwlock);
4359 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
4360 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
4361 			count++;
4362 	}
4363 	LIST_FOREACH(z, &uma_cachezones, uz_link)
4364 		count++;
4365 
4366 	rw_runlock(&uma_rwlock);
4367 	return (sysctl_handle_int(oidp, &count, 0, req));
4368 }
4369 
4370 static void
4371 uma_vm_zone_stats(struct uma_type_header *uth, uma_zone_t z, struct sbuf *sbuf,
4372     struct uma_percpu_stat *ups, bool internal)
4373 {
4374 	uma_zone_domain_t zdom;
4375 	uma_cache_t cache;
4376 	int i;
4377 
4378 
4379 	for (i = 0; i < vm_ndomains; i++) {
4380 		zdom = &z->uz_domain[i];
4381 		uth->uth_zone_free += zdom->uzd_nitems;
4382 	}
4383 	uth->uth_allocs = counter_u64_fetch(z->uz_allocs);
4384 	uth->uth_frees = counter_u64_fetch(z->uz_frees);
4385 	uth->uth_fails = counter_u64_fetch(z->uz_fails);
4386 	uth->uth_sleeps = z->uz_sleeps;
4387 	uth->uth_xdomain = z->uz_xdomain;
4388 
4389 	/*
4390 	 * While it is not normally safe to access the cache bucket pointers
4391 	 * while not on the CPU that owns the cache, we only allow the pointers
4392 	 * to be exchanged without the zone lock held, not invalidated, so
4393 	 * accept the possible race associated with bucket exchange during
4394 	 * monitoring.  Use atomic_load_ptr() to ensure that the bucket pointers
4395 	 * are loaded only once.
4396 	 */
4397 	for (i = 0; i < mp_maxid + 1; i++) {
4398 		bzero(&ups[i], sizeof(*ups));
4399 		if (internal || CPU_ABSENT(i))
4400 			continue;
4401 		cache = &z->uz_cpu[i];
4402 		ups[i].ups_cache_free += cache->uc_allocbucket.ucb_cnt;
4403 		ups[i].ups_cache_free += cache->uc_freebucket.ucb_cnt;
4404 		ups[i].ups_cache_free += cache->uc_crossbucket.ucb_cnt;
4405 		ups[i].ups_allocs = cache->uc_allocs;
4406 		ups[i].ups_frees = cache->uc_frees;
4407 	}
4408 }
4409 
4410 static int
4411 sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS)
4412 {
4413 	struct uma_stream_header ush;
4414 	struct uma_type_header uth;
4415 	struct uma_percpu_stat *ups;
4416 	struct sbuf sbuf;
4417 	uma_keg_t kz;
4418 	uma_zone_t z;
4419 	int count, error, i;
4420 
4421 	error = sysctl_wire_old_buffer(req, 0);
4422 	if (error != 0)
4423 		return (error);
4424 	sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
4425 	sbuf_clear_flags(&sbuf, SBUF_INCLUDENUL);
4426 	ups = malloc((mp_maxid + 1) * sizeof(*ups), M_TEMP, M_WAITOK);
4427 
4428 	count = 0;
4429 	rw_rlock(&uma_rwlock);
4430 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
4431 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
4432 			count++;
4433 	}
4434 
4435 	LIST_FOREACH(z, &uma_cachezones, uz_link)
4436 		count++;
4437 
4438 	/*
4439 	 * Insert stream header.
4440 	 */
4441 	bzero(&ush, sizeof(ush));
4442 	ush.ush_version = UMA_STREAM_VERSION;
4443 	ush.ush_maxcpus = (mp_maxid + 1);
4444 	ush.ush_count = count;
4445 	(void)sbuf_bcat(&sbuf, &ush, sizeof(ush));
4446 
4447 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
4448 		LIST_FOREACH(z, &kz->uk_zones, uz_link) {
4449 			bzero(&uth, sizeof(uth));
4450 			ZONE_LOCK(z);
4451 			strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
4452 			uth.uth_align = kz->uk_align;
4453 			uth.uth_size = kz->uk_size;
4454 			uth.uth_rsize = kz->uk_rsize;
4455 			if (z->uz_max_items > 0)
4456 				uth.uth_pages = (z->uz_items / kz->uk_ipers) *
4457 					kz->uk_ppera;
4458 			else
4459 				uth.uth_pages = kz->uk_pages;
4460 			uth.uth_maxpages = (z->uz_max_items / kz->uk_ipers) *
4461 			    kz->uk_ppera;
4462 			uth.uth_limit = z->uz_max_items;
4463 			uth.uth_keg_free = z->uz_keg->uk_free;
4464 
4465 			/*
4466 			 * A zone is secondary is it is not the first entry
4467 			 * on the keg's zone list.
4468 			 */
4469 			if ((z->uz_flags & UMA_ZONE_SECONDARY) &&
4470 			    (LIST_FIRST(&kz->uk_zones) != z))
4471 				uth.uth_zone_flags = UTH_ZONE_SECONDARY;
4472 			uma_vm_zone_stats(&uth, z, &sbuf, ups,
4473 			    kz->uk_flags & UMA_ZFLAG_INTERNAL);
4474 			ZONE_UNLOCK(z);
4475 			(void)sbuf_bcat(&sbuf, &uth, sizeof(uth));
4476 			for (i = 0; i < mp_maxid + 1; i++)
4477 				(void)sbuf_bcat(&sbuf, &ups[i], sizeof(ups[i]));
4478 		}
4479 	}
4480 	LIST_FOREACH(z, &uma_cachezones, uz_link) {
4481 		bzero(&uth, sizeof(uth));
4482 		ZONE_LOCK(z);
4483 		strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
4484 		uth.uth_size = z->uz_size;
4485 		uma_vm_zone_stats(&uth, z, &sbuf, ups, false);
4486 		ZONE_UNLOCK(z);
4487 		(void)sbuf_bcat(&sbuf, &uth, sizeof(uth));
4488 		for (i = 0; i < mp_maxid + 1; i++)
4489 			(void)sbuf_bcat(&sbuf, &ups[i], sizeof(ups[i]));
4490 	}
4491 
4492 	rw_runlock(&uma_rwlock);
4493 	error = sbuf_finish(&sbuf);
4494 	sbuf_delete(&sbuf);
4495 	free(ups, M_TEMP);
4496 	return (error);
4497 }
4498 
4499 int
4500 sysctl_handle_uma_zone_max(SYSCTL_HANDLER_ARGS)
4501 {
4502 	uma_zone_t zone = *(uma_zone_t *)arg1;
4503 	int error, max;
4504 
4505 	max = uma_zone_get_max(zone);
4506 	error = sysctl_handle_int(oidp, &max, 0, req);
4507 	if (error || !req->newptr)
4508 		return (error);
4509 
4510 	uma_zone_set_max(zone, max);
4511 
4512 	return (0);
4513 }
4514 
4515 int
4516 sysctl_handle_uma_zone_cur(SYSCTL_HANDLER_ARGS)
4517 {
4518 	uma_zone_t zone;
4519 	int cur;
4520 
4521 	/*
4522 	 * Some callers want to add sysctls for global zones that
4523 	 * may not yet exist so they pass a pointer to a pointer.
4524 	 */
4525 	if (arg2 == 0)
4526 		zone = *(uma_zone_t *)arg1;
4527 	else
4528 		zone = arg1;
4529 	cur = uma_zone_get_cur(zone);
4530 	return (sysctl_handle_int(oidp, &cur, 0, req));
4531 }
4532 
4533 static int
4534 sysctl_handle_uma_zone_allocs(SYSCTL_HANDLER_ARGS)
4535 {
4536 	uma_zone_t zone = arg1;
4537 	uint64_t cur;
4538 
4539 	cur = uma_zone_get_allocs(zone);
4540 	return (sysctl_handle_64(oidp, &cur, 0, req));
4541 }
4542 
4543 static int
4544 sysctl_handle_uma_zone_frees(SYSCTL_HANDLER_ARGS)
4545 {
4546 	uma_zone_t zone = arg1;
4547 	uint64_t cur;
4548 
4549 	cur = uma_zone_get_frees(zone);
4550 	return (sysctl_handle_64(oidp, &cur, 0, req));
4551 }
4552 
4553 static int
4554 sysctl_handle_uma_zone_flags(SYSCTL_HANDLER_ARGS)
4555 {
4556 	struct sbuf sbuf;
4557 	uma_zone_t zone = arg1;
4558 	int error;
4559 
4560 	sbuf_new_for_sysctl(&sbuf, NULL, 0, req);
4561 	if (zone->uz_flags != 0)
4562 		sbuf_printf(&sbuf, "0x%b", zone->uz_flags, PRINT_UMA_ZFLAGS);
4563 	else
4564 		sbuf_printf(&sbuf, "0");
4565 	error = sbuf_finish(&sbuf);
4566 	sbuf_delete(&sbuf);
4567 
4568 	return (error);
4569 }
4570 
4571 static int
4572 sysctl_handle_uma_slab_efficiency(SYSCTL_HANDLER_ARGS)
4573 {
4574 	uma_keg_t keg = arg1;
4575 	int avail, effpct, total;
4576 
4577 	total = keg->uk_ppera * PAGE_SIZE;
4578 	if ((keg->uk_flags & UMA_ZONE_OFFPAGE) != 0)
4579 		total += slab_sizeof(SLAB_MAX_SETSIZE);
4580 	/*
4581 	 * We consider the client's requested size and alignment here, not the
4582 	 * real size determination uk_rsize, because we also adjust the real
4583 	 * size for internal implementation reasons (max bitset size).
4584 	 */
4585 	avail = keg->uk_ipers * roundup2(keg->uk_size, keg->uk_align + 1);
4586 	if ((keg->uk_flags & UMA_ZONE_PCPU) != 0)
4587 		avail *= mp_maxid + 1;
4588 	effpct = 100 * avail / total;
4589 	return (sysctl_handle_int(oidp, &effpct, 0, req));
4590 }
4591 
4592 #ifdef INVARIANTS
4593 static uma_slab_t
4594 uma_dbg_getslab(uma_zone_t zone, void *item)
4595 {
4596 	uma_slab_t slab;
4597 	uma_keg_t keg;
4598 	uint8_t *mem;
4599 
4600 	mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
4601 	if (zone->uz_flags & UMA_ZONE_VTOSLAB) {
4602 		slab = vtoslab((vm_offset_t)mem);
4603 	} else {
4604 		/*
4605 		 * It is safe to return the slab here even though the
4606 		 * zone is unlocked because the item's allocation state
4607 		 * essentially holds a reference.
4608 		 */
4609 		if (zone->uz_lockptr == &zone->uz_lock)
4610 			return (NULL);
4611 		ZONE_LOCK(zone);
4612 		keg = zone->uz_keg;
4613 		if (keg->uk_flags & UMA_ZONE_HASH)
4614 			slab = hash_sfind(&keg->uk_hash, mem);
4615 		else
4616 			slab = (uma_slab_t)(mem + keg->uk_pgoff);
4617 		ZONE_UNLOCK(zone);
4618 	}
4619 
4620 	return (slab);
4621 }
4622 
4623 static bool
4624 uma_dbg_zskip(uma_zone_t zone, void *mem)
4625 {
4626 
4627 	if (zone->uz_lockptr == &zone->uz_lock)
4628 		return (true);
4629 
4630 	return (uma_dbg_kskip(zone->uz_keg, mem));
4631 }
4632 
4633 static bool
4634 uma_dbg_kskip(uma_keg_t keg, void *mem)
4635 {
4636 	uintptr_t idx;
4637 
4638 	if (dbg_divisor == 0)
4639 		return (true);
4640 
4641 	if (dbg_divisor == 1)
4642 		return (false);
4643 
4644 	idx = (uintptr_t)mem >> PAGE_SHIFT;
4645 	if (keg->uk_ipers > 1) {
4646 		idx *= keg->uk_ipers;
4647 		idx += ((uintptr_t)mem & PAGE_MASK) / keg->uk_rsize;
4648 	}
4649 
4650 	if ((idx / dbg_divisor) * dbg_divisor != idx) {
4651 		counter_u64_add(uma_skip_cnt, 1);
4652 		return (true);
4653 	}
4654 	counter_u64_add(uma_dbg_cnt, 1);
4655 
4656 	return (false);
4657 }
4658 
4659 /*
4660  * Set up the slab's freei data such that uma_dbg_free can function.
4661  *
4662  */
4663 static void
4664 uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item)
4665 {
4666 	uma_keg_t keg;
4667 	int freei;
4668 
4669 	if (slab == NULL) {
4670 		slab = uma_dbg_getslab(zone, item);
4671 		if (slab == NULL)
4672 			panic("uma: item %p did not belong to zone %s\n",
4673 			    item, zone->uz_name);
4674 	}
4675 	keg = zone->uz_keg;
4676 	freei = slab_item_index(slab, keg, item);
4677 
4678 	if (BIT_ISSET(keg->uk_ipers, freei, slab_dbg_bits(slab, keg)))
4679 		panic("Duplicate alloc of %p from zone %p(%s) slab %p(%d)\n",
4680 		    item, zone, zone->uz_name, slab, freei);
4681 	BIT_SET_ATOMIC(keg->uk_ipers, freei, slab_dbg_bits(slab, keg));
4682 }
4683 
4684 /*
4685  * Verifies freed addresses.  Checks for alignment, valid slab membership
4686  * and duplicate frees.
4687  *
4688  */
4689 static void
4690 uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item)
4691 {
4692 	uma_keg_t keg;
4693 	int freei;
4694 
4695 	if (slab == NULL) {
4696 		slab = uma_dbg_getslab(zone, item);
4697 		if (slab == NULL)
4698 			panic("uma: Freed item %p did not belong to zone %s\n",
4699 			    item, zone->uz_name);
4700 	}
4701 	keg = zone->uz_keg;
4702 	freei = slab_item_index(slab, keg, item);
4703 
4704 	if (freei >= keg->uk_ipers)
4705 		panic("Invalid free of %p from zone %p(%s) slab %p(%d)\n",
4706 		    item, zone, zone->uz_name, slab, freei);
4707 
4708 	if (slab_item(slab, keg, freei) != item)
4709 		panic("Unaligned free of %p from zone %p(%s) slab %p(%d)\n",
4710 		    item, zone, zone->uz_name, slab, freei);
4711 
4712 	if (!BIT_ISSET(keg->uk_ipers, freei, slab_dbg_bits(slab, keg)))
4713 		panic("Duplicate free of %p from zone %p(%s) slab %p(%d)\n",
4714 		    item, zone, zone->uz_name, slab, freei);
4715 
4716 	BIT_CLR_ATOMIC(keg->uk_ipers, freei, slab_dbg_bits(slab, keg));
4717 }
4718 #endif /* INVARIANTS */
4719 
4720 #ifdef DDB
4721 static int64_t
4722 get_uma_stats(uma_keg_t kz, uma_zone_t z, uint64_t *allocs, uint64_t *used,
4723     uint64_t *sleeps, long *cachefree, uint64_t *xdomain)
4724 {
4725 	uint64_t frees;
4726 	int i;
4727 
4728 	if (kz->uk_flags & UMA_ZFLAG_INTERNAL) {
4729 		*allocs = counter_u64_fetch(z->uz_allocs);
4730 		frees = counter_u64_fetch(z->uz_frees);
4731 		*sleeps = z->uz_sleeps;
4732 		*cachefree = 0;
4733 		*xdomain = 0;
4734 	} else
4735 		uma_zone_sumstat(z, cachefree, allocs, &frees, sleeps,
4736 		    xdomain);
4737 	if (!((z->uz_flags & UMA_ZONE_SECONDARY) &&
4738 	    (LIST_FIRST(&kz->uk_zones) != z)))
4739 		*cachefree += kz->uk_free;
4740 	for (i = 0; i < vm_ndomains; i++)
4741 		*cachefree += z->uz_domain[i].uzd_nitems;
4742 	*used = *allocs - frees;
4743 	return (((int64_t)*used + *cachefree) * kz->uk_size);
4744 }
4745 
4746 DB_SHOW_COMMAND(uma, db_show_uma)
4747 {
4748 	const char *fmt_hdr, *fmt_entry;
4749 	uma_keg_t kz;
4750 	uma_zone_t z;
4751 	uint64_t allocs, used, sleeps, xdomain;
4752 	long cachefree;
4753 	/* variables for sorting */
4754 	uma_keg_t cur_keg;
4755 	uma_zone_t cur_zone, last_zone;
4756 	int64_t cur_size, last_size, size;
4757 	int ties;
4758 
4759 	/* /i option produces machine-parseable CSV output */
4760 	if (modif[0] == 'i') {
4761 		fmt_hdr = "%s,%s,%s,%s,%s,%s,%s,%s,%s\n";
4762 		fmt_entry = "\"%s\",%ju,%jd,%ld,%ju,%ju,%u,%jd,%ju\n";
4763 	} else {
4764 		fmt_hdr = "%18s %6s %7s %7s %11s %7s %7s %10s %8s\n";
4765 		fmt_entry = "%18s %6ju %7jd %7ld %11ju %7ju %7u %10jd %8ju\n";
4766 	}
4767 
4768 	db_printf(fmt_hdr, "Zone", "Size", "Used", "Free", "Requests",
4769 	    "Sleeps", "Bucket", "Total Mem", "XFree");
4770 
4771 	/* Sort the zones with largest size first. */
4772 	last_zone = NULL;
4773 	last_size = INT64_MAX;
4774 	for (;;) {
4775 		cur_zone = NULL;
4776 		cur_size = -1;
4777 		ties = 0;
4778 		LIST_FOREACH(kz, &uma_kegs, uk_link) {
4779 			LIST_FOREACH(z, &kz->uk_zones, uz_link) {
4780 				/*
4781 				 * In the case of size ties, print out zones
4782 				 * in the order they are encountered.  That is,
4783 				 * when we encounter the most recently output
4784 				 * zone, we have already printed all preceding
4785 				 * ties, and we must print all following ties.
4786 				 */
4787 				if (z == last_zone) {
4788 					ties = 1;
4789 					continue;
4790 				}
4791 				size = get_uma_stats(kz, z, &allocs, &used,
4792 				    &sleeps, &cachefree, &xdomain);
4793 				if (size > cur_size && size < last_size + ties)
4794 				{
4795 					cur_size = size;
4796 					cur_zone = z;
4797 					cur_keg = kz;
4798 				}
4799 			}
4800 		}
4801 		if (cur_zone == NULL)
4802 			break;
4803 
4804 		size = get_uma_stats(cur_keg, cur_zone, &allocs, &used,
4805 		    &sleeps, &cachefree, &xdomain);
4806 		db_printf(fmt_entry, cur_zone->uz_name,
4807 		    (uintmax_t)cur_keg->uk_size, (intmax_t)used, cachefree,
4808 		    (uintmax_t)allocs, (uintmax_t)sleeps,
4809 		    (unsigned)cur_zone->uz_bucket_size, (intmax_t)size,
4810 		    xdomain);
4811 
4812 		if (db_pager_quit)
4813 			return;
4814 		last_zone = cur_zone;
4815 		last_size = cur_size;
4816 	}
4817 }
4818 
4819 DB_SHOW_COMMAND(umacache, db_show_umacache)
4820 {
4821 	uma_zone_t z;
4822 	uint64_t allocs, frees;
4823 	long cachefree;
4824 	int i;
4825 
4826 	db_printf("%18s %8s %8s %8s %12s %8s\n", "Zone", "Size", "Used", "Free",
4827 	    "Requests", "Bucket");
4828 	LIST_FOREACH(z, &uma_cachezones, uz_link) {
4829 		uma_zone_sumstat(z, &cachefree, &allocs, &frees, NULL, NULL);
4830 		for (i = 0; i < vm_ndomains; i++)
4831 			cachefree += z->uz_domain[i].uzd_nitems;
4832 		db_printf("%18s %8ju %8jd %8ld %12ju %8u\n",
4833 		    z->uz_name, (uintmax_t)z->uz_size,
4834 		    (intmax_t)(allocs - frees), cachefree,
4835 		    (uintmax_t)allocs, z->uz_bucket_size);
4836 		if (db_pager_quit)
4837 			return;
4838 	}
4839 }
4840 #endif	/* DDB */
4841