xref: /freebsd/sys/vm/uma_core.c (revision 2f513db7)
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/sleepqueue.h>
79 #include <sys/smp.h>
80 #include <sys/smr.h>
81 #include <sys/taskqueue.h>
82 #include <sys/vmmeter.h>
83 
84 #include <vm/vm.h>
85 #include <vm/vm_domainset.h>
86 #include <vm/vm_object.h>
87 #include <vm/vm_page.h>
88 #include <vm/vm_pageout.h>
89 #include <vm/vm_param.h>
90 #include <vm/vm_phys.h>
91 #include <vm/vm_pagequeue.h>
92 #include <vm/vm_map.h>
93 #include <vm/vm_kern.h>
94 #include <vm/vm_extern.h>
95 #include <vm/uma.h>
96 #include <vm/uma_int.h>
97 #include <vm/uma_dbg.h>
98 
99 #include <ddb/ddb.h>
100 
101 #ifdef DEBUG_MEMGUARD
102 #include <vm/memguard.h>
103 #endif
104 
105 #include <machine/md_var.h>
106 
107 #ifdef INVARIANTS
108 #define	UMA_ALWAYS_CTORDTOR	1
109 #else
110 #define	UMA_ALWAYS_CTORDTOR	0
111 #endif
112 
113 /*
114  * This is the zone and keg from which all zones are spawned.
115  */
116 static uma_zone_t kegs;
117 static uma_zone_t zones;
118 
119 /*
120  * These are the two zones from which all offpage uma_slab_ts are allocated.
121  *
122  * One zone is for slab headers that can represent a larger number of items,
123  * making the slabs themselves more efficient, and the other zone is for
124  * headers that are smaller and represent fewer items, making the headers more
125  * efficient.
126  */
127 #define	SLABZONE_SIZE(setsize)					\
128     (sizeof(struct uma_hash_slab) + BITSET_SIZE(setsize) * SLAB_BITSETS)
129 #define	SLABZONE0_SETSIZE	(PAGE_SIZE / 16)
130 #define	SLABZONE1_SETSIZE	SLAB_MAX_SETSIZE
131 #define	SLABZONE0_SIZE	SLABZONE_SIZE(SLABZONE0_SETSIZE)
132 #define	SLABZONE1_SIZE	SLABZONE_SIZE(SLABZONE1_SETSIZE)
133 static uma_zone_t slabzones[2];
134 
135 /*
136  * The initial hash tables come out of this zone so they can be allocated
137  * prior to malloc coming up.
138  */
139 static uma_zone_t hashzone;
140 
141 /* The boot-time adjusted value for cache line alignment. */
142 int uma_align_cache = 64 - 1;
143 
144 static MALLOC_DEFINE(M_UMAHASH, "UMAHash", "UMA Hash Buckets");
145 static MALLOC_DEFINE(M_UMA, "UMA", "UMA Misc");
146 
147 /*
148  * Are we allowed to allocate buckets?
149  */
150 static int bucketdisable = 1;
151 
152 /* Linked list of all kegs in the system */
153 static LIST_HEAD(,uma_keg) uma_kegs = LIST_HEAD_INITIALIZER(uma_kegs);
154 
155 /* Linked list of all cache-only zones in the system */
156 static LIST_HEAD(,uma_zone) uma_cachezones =
157     LIST_HEAD_INITIALIZER(uma_cachezones);
158 
159 /* This RW lock protects the keg list */
160 static struct rwlock_padalign __exclusive_cache_line uma_rwlock;
161 
162 /*
163  * First available virual address for boot time allocations.
164  */
165 static vm_offset_t bootstart;
166 static vm_offset_t bootmem;
167 
168 static struct sx uma_reclaim_lock;
169 
170 /*
171  * kmem soft limit, initialized by uma_set_limit().  Ensure that early
172  * allocations don't trigger a wakeup of the reclaim thread.
173  */
174 unsigned long uma_kmem_limit = LONG_MAX;
175 SYSCTL_ULONG(_vm, OID_AUTO, uma_kmem_limit, CTLFLAG_RD, &uma_kmem_limit, 0,
176     "UMA kernel memory soft limit");
177 unsigned long uma_kmem_total;
178 SYSCTL_ULONG(_vm, OID_AUTO, uma_kmem_total, CTLFLAG_RD, &uma_kmem_total, 0,
179     "UMA kernel memory usage");
180 
181 /* Is the VM done starting up? */
182 static enum {
183 	BOOT_COLD,
184 	BOOT_KVA,
185 	BOOT_RUNNING,
186 	BOOT_SHUTDOWN,
187 } booted = BOOT_COLD;
188 
189 /*
190  * This is the handle used to schedule events that need to happen
191  * outside of the allocation fast path.
192  */
193 static struct callout uma_callout;
194 #define	UMA_TIMEOUT	20		/* Seconds for callout interval. */
195 
196 /*
197  * This structure is passed as the zone ctor arg so that I don't have to create
198  * a special allocation function just for zones.
199  */
200 struct uma_zctor_args {
201 	const char *name;
202 	size_t size;
203 	uma_ctor ctor;
204 	uma_dtor dtor;
205 	uma_init uminit;
206 	uma_fini fini;
207 	uma_import import;
208 	uma_release release;
209 	void *arg;
210 	uma_keg_t keg;
211 	int align;
212 	uint32_t flags;
213 };
214 
215 struct uma_kctor_args {
216 	uma_zone_t zone;
217 	size_t size;
218 	uma_init uminit;
219 	uma_fini fini;
220 	int align;
221 	uint32_t flags;
222 };
223 
224 struct uma_bucket_zone {
225 	uma_zone_t	ubz_zone;
226 	char		*ubz_name;
227 	int		ubz_entries;	/* Number of items it can hold. */
228 	int		ubz_maxsize;	/* Maximum allocation size per-item. */
229 };
230 
231 /*
232  * Compute the actual number of bucket entries to pack them in power
233  * of two sizes for more efficient space utilization.
234  */
235 #define	BUCKET_SIZE(n)						\
236     (((sizeof(void *) * (n)) - sizeof(struct uma_bucket)) / sizeof(void *))
237 
238 #define	BUCKET_MAX	BUCKET_SIZE(256)
239 #define	BUCKET_MIN	2
240 
241 struct uma_bucket_zone bucket_zones[] = {
242 	/* Literal bucket sizes. */
243 	{ NULL, "2 Bucket", 2, 4096 },
244 	{ NULL, "4 Bucket", 4, 3072 },
245 	{ NULL, "8 Bucket", 8, 2048 },
246 	{ NULL, "16 Bucket", 16, 1024 },
247 	/* Rounded down power of 2 sizes for efficiency. */
248 	{ NULL, "32 Bucket", BUCKET_SIZE(32), 512 },
249 	{ NULL, "64 Bucket", BUCKET_SIZE(64), 256 },
250 	{ NULL, "128 Bucket", BUCKET_SIZE(128), 128 },
251 	{ NULL, "256 Bucket", BUCKET_SIZE(256), 64 },
252 	{ NULL, NULL, 0}
253 };
254 
255 /*
256  * Flags and enumerations to be passed to internal functions.
257  */
258 enum zfreeskip {
259 	SKIP_NONE =	0,
260 	SKIP_CNT =	0x00000001,
261 	SKIP_DTOR =	0x00010000,
262 	SKIP_FINI =	0x00020000,
263 };
264 
265 /* Prototypes.. */
266 
267 void	uma_startup1(vm_offset_t);
268 void	uma_startup2(void);
269 
270 static void *noobj_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
271 static void *page_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
272 static void *pcpu_page_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
273 static void *startup_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
274 static void *contig_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
275 static void page_free(void *, vm_size_t, uint8_t);
276 static void pcpu_page_free(void *, vm_size_t, uint8_t);
277 static uma_slab_t keg_alloc_slab(uma_keg_t, uma_zone_t, int, int, int);
278 static void cache_drain(uma_zone_t);
279 static void bucket_drain(uma_zone_t, uma_bucket_t);
280 static void bucket_cache_reclaim(uma_zone_t zone, bool);
281 static int keg_ctor(void *, int, void *, int);
282 static void keg_dtor(void *, int, void *);
283 static int zone_ctor(void *, int, void *, int);
284 static void zone_dtor(void *, int, void *);
285 static inline void item_dtor(uma_zone_t zone, void *item, int size,
286     void *udata, enum zfreeskip skip);
287 static int zero_init(void *, int, int);
288 static void zone_foreach(void (*zfunc)(uma_zone_t, void *), void *);
289 static void zone_foreach_unlocked(void (*zfunc)(uma_zone_t, void *), void *);
290 static void zone_timeout(uma_zone_t zone, void *);
291 static int hash_alloc(struct uma_hash *, u_int);
292 static int hash_expand(struct uma_hash *, struct uma_hash *);
293 static void hash_free(struct uma_hash *hash);
294 static void uma_timeout(void *);
295 static void uma_startup3(void);
296 static void uma_shutdown(void);
297 static void *zone_alloc_item(uma_zone_t, void *, int, int);
298 static void zone_free_item(uma_zone_t, void *, void *, enum zfreeskip);
299 static int zone_alloc_limit(uma_zone_t zone, int count, int flags);
300 static void zone_free_limit(uma_zone_t zone, int count);
301 static void bucket_enable(void);
302 static void bucket_init(void);
303 static uma_bucket_t bucket_alloc(uma_zone_t zone, void *, int);
304 static void bucket_free(uma_zone_t zone, uma_bucket_t, void *);
305 static void bucket_zone_drain(void);
306 static uma_bucket_t zone_alloc_bucket(uma_zone_t, void *, int, int);
307 static void *slab_alloc_item(uma_keg_t keg, uma_slab_t slab);
308 static void slab_free_item(uma_zone_t zone, uma_slab_t slab, void *item);
309 static uma_keg_t uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit,
310     uma_fini fini, int align, uint32_t flags);
311 static int zone_import(void *, void **, int, int, int);
312 static void zone_release(void *, void **, int);
313 static bool cache_alloc(uma_zone_t, uma_cache_t, void *, int);
314 static bool cache_free(uma_zone_t, uma_cache_t, void *, void *, int);
315 
316 static int sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS);
317 static int sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS);
318 static int sysctl_handle_uma_zone_allocs(SYSCTL_HANDLER_ARGS);
319 static int sysctl_handle_uma_zone_frees(SYSCTL_HANDLER_ARGS);
320 static int sysctl_handle_uma_zone_flags(SYSCTL_HANDLER_ARGS);
321 static int sysctl_handle_uma_slab_efficiency(SYSCTL_HANDLER_ARGS);
322 static int sysctl_handle_uma_zone_items(SYSCTL_HANDLER_ARGS);
323 
324 static uint64_t uma_zone_get_allocs(uma_zone_t zone);
325 
326 static SYSCTL_NODE(_vm, OID_AUTO, debug, CTLFLAG_RD, 0,
327     "Memory allocation debugging");
328 
329 #ifdef INVARIANTS
330 static uint64_t uma_keg_get_allocs(uma_keg_t zone);
331 static inline struct noslabbits *slab_dbg_bits(uma_slab_t slab, uma_keg_t keg);
332 
333 static bool uma_dbg_kskip(uma_keg_t keg, void *mem);
334 static bool uma_dbg_zskip(uma_zone_t zone, void *mem);
335 static void uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item);
336 static void uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item);
337 
338 static u_int dbg_divisor = 1;
339 SYSCTL_UINT(_vm_debug, OID_AUTO, divisor,
340     CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &dbg_divisor, 0,
341     "Debug & thrash every this item in memory allocator");
342 
343 static counter_u64_t uma_dbg_cnt = EARLY_COUNTER;
344 static counter_u64_t uma_skip_cnt = EARLY_COUNTER;
345 SYSCTL_COUNTER_U64(_vm_debug, OID_AUTO, trashed, CTLFLAG_RD,
346     &uma_dbg_cnt, "memory items debugged");
347 SYSCTL_COUNTER_U64(_vm_debug, OID_AUTO, skipped, CTLFLAG_RD,
348     &uma_skip_cnt, "memory items skipped, not debugged");
349 #endif
350 
351 SYSINIT(uma_startup3, SI_SUB_VM_CONF, SI_ORDER_SECOND, uma_startup3, NULL);
352 
353 SYSCTL_NODE(_vm, OID_AUTO, uma, CTLFLAG_RW, 0, "Universal Memory Allocator");
354 
355 SYSCTL_PROC(_vm, OID_AUTO, zone_count, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLTYPE_INT,
356     0, 0, sysctl_vm_zone_count, "I", "Number of UMA zones");
357 
358 SYSCTL_PROC(_vm, OID_AUTO, zone_stats, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLTYPE_STRUCT,
359     0, 0, sysctl_vm_zone_stats, "s,struct uma_type_header", "Zone Stats");
360 
361 static int zone_warnings = 1;
362 SYSCTL_INT(_vm, OID_AUTO, zone_warnings, CTLFLAG_RWTUN, &zone_warnings, 0,
363     "Warn when UMA zones becomes full");
364 
365 static int multipage_slabs = 1;
366 TUNABLE_INT("vm.debug.uma_multipage_slabs", &multipage_slabs);
367 SYSCTL_INT(_vm_debug, OID_AUTO, uma_multipage_slabs,
368     CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &multipage_slabs, 0,
369     "UMA may choose larger slab sizes for better efficiency");
370 
371 /*
372  * Select the slab zone for an offpage slab with the given maximum item count.
373  */
374 static inline uma_zone_t
375 slabzone(int ipers)
376 {
377 
378 	return (slabzones[ipers > SLABZONE0_SETSIZE]);
379 }
380 
381 /*
382  * This routine checks to see whether or not it's safe to enable buckets.
383  */
384 static void
385 bucket_enable(void)
386 {
387 
388 	KASSERT(booted >= BOOT_KVA, ("Bucket enable before init"));
389 	bucketdisable = vm_page_count_min();
390 }
391 
392 /*
393  * Initialize bucket_zones, the array of zones of buckets of various sizes.
394  *
395  * For each zone, calculate the memory required for each bucket, consisting
396  * of the header and an array of pointers.
397  */
398 static void
399 bucket_init(void)
400 {
401 	struct uma_bucket_zone *ubz;
402 	int size;
403 
404 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++) {
405 		size = roundup(sizeof(struct uma_bucket), sizeof(void *));
406 		size += sizeof(void *) * ubz->ubz_entries;
407 		ubz->ubz_zone = uma_zcreate(ubz->ubz_name, size,
408 		    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR,
409 		    UMA_ZONE_MTXCLASS | UMA_ZFLAG_BUCKET |
410 		    UMA_ZONE_FIRSTTOUCH);
411 	}
412 }
413 
414 /*
415  * Given a desired number of entries for a bucket, return the zone from which
416  * to allocate the bucket.
417  */
418 static struct uma_bucket_zone *
419 bucket_zone_lookup(int entries)
420 {
421 	struct uma_bucket_zone *ubz;
422 
423 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
424 		if (ubz->ubz_entries >= entries)
425 			return (ubz);
426 	ubz--;
427 	return (ubz);
428 }
429 
430 static struct uma_bucket_zone *
431 bucket_zone_max(uma_zone_t zone, int nitems)
432 {
433 	struct uma_bucket_zone *ubz;
434 	int bpcpu;
435 
436 	bpcpu = 2;
437 	if ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) != 0)
438 		/* Count the cross-domain bucket. */
439 		bpcpu++;
440 
441 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
442 		if (ubz->ubz_entries * bpcpu * mp_ncpus > nitems)
443 			break;
444 	if (ubz == &bucket_zones[0])
445 		ubz = NULL;
446 	else
447 		ubz--;
448 	return (ubz);
449 }
450 
451 static int
452 bucket_select(int size)
453 {
454 	struct uma_bucket_zone *ubz;
455 
456 	ubz = &bucket_zones[0];
457 	if (size > ubz->ubz_maxsize)
458 		return MAX((ubz->ubz_maxsize * ubz->ubz_entries) / size, 1);
459 
460 	for (; ubz->ubz_entries != 0; ubz++)
461 		if (ubz->ubz_maxsize < size)
462 			break;
463 	ubz--;
464 	return (ubz->ubz_entries);
465 }
466 
467 static uma_bucket_t
468 bucket_alloc(uma_zone_t zone, void *udata, int flags)
469 {
470 	struct uma_bucket_zone *ubz;
471 	uma_bucket_t bucket;
472 
473 	/*
474 	 * Don't allocate buckets early in boot.
475 	 */
476 	if (__predict_false(booted < BOOT_KVA))
477 		return (NULL);
478 
479 	/*
480 	 * To limit bucket recursion we store the original zone flags
481 	 * in a cookie passed via zalloc_arg/zfree_arg.  This allows the
482 	 * NOVM flag to persist even through deep recursions.  We also
483 	 * store ZFLAG_BUCKET once we have recursed attempting to allocate
484 	 * a bucket for a bucket zone so we do not allow infinite bucket
485 	 * recursion.  This cookie will even persist to frees of unused
486 	 * buckets via the allocation path or bucket allocations in the
487 	 * free path.
488 	 */
489 	if ((zone->uz_flags & UMA_ZFLAG_BUCKET) == 0)
490 		udata = (void *)(uintptr_t)zone->uz_flags;
491 	else {
492 		if ((uintptr_t)udata & UMA_ZFLAG_BUCKET)
493 			return (NULL);
494 		udata = (void *)((uintptr_t)udata | UMA_ZFLAG_BUCKET);
495 	}
496 	if (((uintptr_t)udata & UMA_ZONE_VM) != 0)
497 		flags |= M_NOVM;
498 	ubz = bucket_zone_lookup(zone->uz_bucket_size);
499 	if (ubz->ubz_zone == zone && (ubz + 1)->ubz_entries != 0)
500 		ubz++;
501 	bucket = uma_zalloc_arg(ubz->ubz_zone, udata, flags);
502 	if (bucket) {
503 #ifdef INVARIANTS
504 		bzero(bucket->ub_bucket, sizeof(void *) * ubz->ubz_entries);
505 #endif
506 		bucket->ub_cnt = 0;
507 		bucket->ub_entries = ubz->ubz_entries;
508 		bucket->ub_seq = SMR_SEQ_INVALID;
509 		CTR3(KTR_UMA, "bucket_alloc: zone %s(%p) allocated bucket %p",
510 		    zone->uz_name, zone, bucket);
511 	}
512 
513 	return (bucket);
514 }
515 
516 static void
517 bucket_free(uma_zone_t zone, uma_bucket_t bucket, void *udata)
518 {
519 	struct uma_bucket_zone *ubz;
520 
521 	KASSERT(bucket->ub_cnt == 0,
522 	    ("bucket_free: Freeing a non free bucket."));
523 	KASSERT(bucket->ub_seq == SMR_SEQ_INVALID,
524 	    ("bucket_free: Freeing an SMR bucket."));
525 	if ((zone->uz_flags & UMA_ZFLAG_BUCKET) == 0)
526 		udata = (void *)(uintptr_t)zone->uz_flags;
527 	ubz = bucket_zone_lookup(bucket->ub_entries);
528 	uma_zfree_arg(ubz->ubz_zone, bucket, udata);
529 }
530 
531 static void
532 bucket_zone_drain(void)
533 {
534 	struct uma_bucket_zone *ubz;
535 
536 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
537 		uma_zone_reclaim(ubz->ubz_zone, UMA_RECLAIM_DRAIN);
538 }
539 
540 /*
541  * Attempt to satisfy an allocation by retrieving a full bucket from one of the
542  * zone's caches.  If a bucket is found the zone is not locked on return.
543  */
544 static uma_bucket_t
545 zone_fetch_bucket(uma_zone_t zone, uma_zone_domain_t zdom)
546 {
547 	uma_bucket_t bucket;
548 	int i;
549 	bool dtor = false;
550 
551 	ZONE_LOCK_ASSERT(zone);
552 
553 	if ((bucket = STAILQ_FIRST(&zdom->uzd_buckets)) == NULL)
554 		return (NULL);
555 
556 	/* SMR Buckets can not be re-used until readers expire. */
557 	if ((zone->uz_flags & UMA_ZONE_SMR) != 0 &&
558 	    bucket->ub_seq != SMR_SEQ_INVALID) {
559 		if (!smr_poll(zone->uz_smr, bucket->ub_seq, false))
560 			return (NULL);
561 		bucket->ub_seq = SMR_SEQ_INVALID;
562 		dtor = (zone->uz_dtor != NULL) || UMA_ALWAYS_CTORDTOR;
563 	}
564 	MPASS(zdom->uzd_nitems >= bucket->ub_cnt);
565 	STAILQ_REMOVE_HEAD(&zdom->uzd_buckets, ub_link);
566 	zdom->uzd_nitems -= bucket->ub_cnt;
567 	if (zdom->uzd_imin > zdom->uzd_nitems)
568 		zdom->uzd_imin = zdom->uzd_nitems;
569 	zone->uz_bkt_count -= bucket->ub_cnt;
570 	ZONE_UNLOCK(zone);
571 	if (dtor)
572 		for (i = 0; i < bucket->ub_cnt; i++)
573 			item_dtor(zone, bucket->ub_bucket[i], zone->uz_size,
574 			    NULL, SKIP_NONE);
575 
576 	return (bucket);
577 }
578 
579 /*
580  * Insert a full bucket into the specified cache.  The "ws" parameter indicates
581  * whether the bucket's contents should be counted as part of the zone's working
582  * set.
583  */
584 static void
585 zone_put_bucket(uma_zone_t zone, uma_zone_domain_t zdom, uma_bucket_t bucket,
586     const bool ws)
587 {
588 
589 	ZONE_LOCK_ASSERT(zone);
590 	KASSERT(!ws || zone->uz_bkt_count < zone->uz_bkt_max,
591 	    ("%s: zone %p overflow", __func__, zone));
592 
593 	STAILQ_INSERT_TAIL(&zdom->uzd_buckets, bucket, ub_link);
594 	zdom->uzd_nitems += bucket->ub_cnt;
595 	if (ws && zdom->uzd_imax < zdom->uzd_nitems)
596 		zdom->uzd_imax = zdom->uzd_nitems;
597 	zone->uz_bkt_count += bucket->ub_cnt;
598 }
599 
600 /* Pops an item out of a per-cpu cache bucket. */
601 static inline void *
602 cache_bucket_pop(uma_cache_t cache, uma_cache_bucket_t bucket)
603 {
604 	void *item;
605 
606 	CRITICAL_ASSERT(curthread);
607 
608 	bucket->ucb_cnt--;
609 	item = bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt];
610 #ifdef INVARIANTS
611 	bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt] = NULL;
612 	KASSERT(item != NULL, ("uma_zalloc: Bucket pointer mangled."));
613 #endif
614 	cache->uc_allocs++;
615 
616 	return (item);
617 }
618 
619 /* Pushes an item into a per-cpu cache bucket. */
620 static inline void
621 cache_bucket_push(uma_cache_t cache, uma_cache_bucket_t bucket, void *item)
622 {
623 
624 	CRITICAL_ASSERT(curthread);
625 	KASSERT(bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt] == NULL,
626 	    ("uma_zfree: Freeing to non free bucket index."));
627 
628 	bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt] = item;
629 	bucket->ucb_cnt++;
630 	cache->uc_frees++;
631 }
632 
633 /*
634  * Unload a UMA bucket from a per-cpu cache.
635  */
636 static inline uma_bucket_t
637 cache_bucket_unload(uma_cache_bucket_t bucket)
638 {
639 	uma_bucket_t b;
640 
641 	b = bucket->ucb_bucket;
642 	if (b != NULL) {
643 		MPASS(b->ub_entries == bucket->ucb_entries);
644 		b->ub_cnt = bucket->ucb_cnt;
645 		bucket->ucb_bucket = NULL;
646 		bucket->ucb_entries = bucket->ucb_cnt = 0;
647 	}
648 
649 	return (b);
650 }
651 
652 static inline uma_bucket_t
653 cache_bucket_unload_alloc(uma_cache_t cache)
654 {
655 
656 	return (cache_bucket_unload(&cache->uc_allocbucket));
657 }
658 
659 static inline uma_bucket_t
660 cache_bucket_unload_free(uma_cache_t cache)
661 {
662 
663 	return (cache_bucket_unload(&cache->uc_freebucket));
664 }
665 
666 static inline uma_bucket_t
667 cache_bucket_unload_cross(uma_cache_t cache)
668 {
669 
670 	return (cache_bucket_unload(&cache->uc_crossbucket));
671 }
672 
673 /*
674  * Load a bucket into a per-cpu cache bucket.
675  */
676 static inline void
677 cache_bucket_load(uma_cache_bucket_t bucket, uma_bucket_t b)
678 {
679 
680 	CRITICAL_ASSERT(curthread);
681 	MPASS(bucket->ucb_bucket == NULL);
682 	MPASS(b->ub_seq == SMR_SEQ_INVALID);
683 
684 	bucket->ucb_bucket = b;
685 	bucket->ucb_cnt = b->ub_cnt;
686 	bucket->ucb_entries = b->ub_entries;
687 }
688 
689 static inline void
690 cache_bucket_load_alloc(uma_cache_t cache, uma_bucket_t b)
691 {
692 
693 	cache_bucket_load(&cache->uc_allocbucket, b);
694 }
695 
696 static inline void
697 cache_bucket_load_free(uma_cache_t cache, uma_bucket_t b)
698 {
699 
700 	cache_bucket_load(&cache->uc_freebucket, b);
701 }
702 
703 #ifdef NUMA
704 static inline void
705 cache_bucket_load_cross(uma_cache_t cache, uma_bucket_t b)
706 {
707 
708 	cache_bucket_load(&cache->uc_crossbucket, b);
709 }
710 #endif
711 
712 /*
713  * Copy and preserve ucb_spare.
714  */
715 static inline void
716 cache_bucket_copy(uma_cache_bucket_t b1, uma_cache_bucket_t b2)
717 {
718 
719 	b1->ucb_bucket = b2->ucb_bucket;
720 	b1->ucb_entries = b2->ucb_entries;
721 	b1->ucb_cnt = b2->ucb_cnt;
722 }
723 
724 /*
725  * Swap two cache buckets.
726  */
727 static inline void
728 cache_bucket_swap(uma_cache_bucket_t b1, uma_cache_bucket_t b2)
729 {
730 	struct uma_cache_bucket b3;
731 
732 	CRITICAL_ASSERT(curthread);
733 
734 	cache_bucket_copy(&b3, b1);
735 	cache_bucket_copy(b1, b2);
736 	cache_bucket_copy(b2, &b3);
737 }
738 
739 static void
740 zone_log_warning(uma_zone_t zone)
741 {
742 	static const struct timeval warninterval = { 300, 0 };
743 
744 	if (!zone_warnings || zone->uz_warning == NULL)
745 		return;
746 
747 	if (ratecheck(&zone->uz_ratecheck, &warninterval))
748 		printf("[zone: %s] %s\n", zone->uz_name, zone->uz_warning);
749 }
750 
751 static inline void
752 zone_maxaction(uma_zone_t zone)
753 {
754 
755 	if (zone->uz_maxaction.ta_func != NULL)
756 		taskqueue_enqueue(taskqueue_thread, &zone->uz_maxaction);
757 }
758 
759 /*
760  * Routine called by timeout which is used to fire off some time interval
761  * based calculations.  (stats, hash size, etc.)
762  *
763  * Arguments:
764  *	arg   Unused
765  *
766  * Returns:
767  *	Nothing
768  */
769 static void
770 uma_timeout(void *unused)
771 {
772 	bucket_enable();
773 	zone_foreach(zone_timeout, NULL);
774 
775 	/* Reschedule this event */
776 	callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
777 }
778 
779 /*
780  * Update the working set size estimate for the zone's bucket cache.
781  * The constants chosen here are somewhat arbitrary.  With an update period of
782  * 20s (UMA_TIMEOUT), this estimate is dominated by zone activity over the
783  * last 100s.
784  */
785 static void
786 zone_domain_update_wss(uma_zone_domain_t zdom)
787 {
788 	long wss;
789 
790 	MPASS(zdom->uzd_imax >= zdom->uzd_imin);
791 	wss = zdom->uzd_imax - zdom->uzd_imin;
792 	zdom->uzd_imax = zdom->uzd_imin = zdom->uzd_nitems;
793 	zdom->uzd_wss = (4 * wss + zdom->uzd_wss) / 5;
794 }
795 
796 /*
797  * Routine to perform timeout driven calculations.  This expands the
798  * hashes and does per cpu statistics aggregation.
799  *
800  *  Returns nothing.
801  */
802 static void
803 zone_timeout(uma_zone_t zone, void *unused)
804 {
805 	uma_keg_t keg;
806 	u_int slabs, pages;
807 
808 	if ((zone->uz_flags & UMA_ZFLAG_HASH) == 0)
809 		goto update_wss;
810 
811 	keg = zone->uz_keg;
812 
813 	/*
814 	 * Hash zones are non-numa by definition so the first domain
815 	 * is the only one present.
816 	 */
817 	KEG_LOCK(keg, 0);
818 	pages = keg->uk_domain[0].ud_pages;
819 
820 	/*
821 	 * Expand the keg hash table.
822 	 *
823 	 * This is done if the number of slabs is larger than the hash size.
824 	 * What I'm trying to do here is completely reduce collisions.  This
825 	 * may be a little aggressive.  Should I allow for two collisions max?
826 	 */
827 	if ((slabs = pages / keg->uk_ppera) > keg->uk_hash.uh_hashsize) {
828 		struct uma_hash newhash;
829 		struct uma_hash oldhash;
830 		int ret;
831 
832 		/*
833 		 * This is so involved because allocating and freeing
834 		 * while the keg lock is held will lead to deadlock.
835 		 * I have to do everything in stages and check for
836 		 * races.
837 		 */
838 		KEG_UNLOCK(keg, 0);
839 		ret = hash_alloc(&newhash, 1 << fls(slabs));
840 		KEG_LOCK(keg, 0);
841 		if (ret) {
842 			if (hash_expand(&keg->uk_hash, &newhash)) {
843 				oldhash = keg->uk_hash;
844 				keg->uk_hash = newhash;
845 			} else
846 				oldhash = newhash;
847 
848 			KEG_UNLOCK(keg, 0);
849 			hash_free(&oldhash);
850 			goto update_wss;
851 		}
852 	}
853 	KEG_UNLOCK(keg, 0);
854 
855 update_wss:
856 	ZONE_LOCK(zone);
857 	for (int i = 0; i < vm_ndomains; i++)
858 		zone_domain_update_wss(&zone->uz_domain[i]);
859 	ZONE_UNLOCK(zone);
860 }
861 
862 /*
863  * Allocate and zero fill the next sized hash table from the appropriate
864  * backing store.
865  *
866  * Arguments:
867  *	hash  A new hash structure with the old hash size in uh_hashsize
868  *
869  * Returns:
870  *	1 on success and 0 on failure.
871  */
872 static int
873 hash_alloc(struct uma_hash *hash, u_int size)
874 {
875 	size_t alloc;
876 
877 	KASSERT(powerof2(size), ("hash size must be power of 2"));
878 	if (size > UMA_HASH_SIZE_INIT)  {
879 		hash->uh_hashsize = size;
880 		alloc = sizeof(hash->uh_slab_hash[0]) * hash->uh_hashsize;
881 		hash->uh_slab_hash = malloc(alloc, M_UMAHASH, M_NOWAIT);
882 	} else {
883 		alloc = sizeof(hash->uh_slab_hash[0]) * UMA_HASH_SIZE_INIT;
884 		hash->uh_slab_hash = zone_alloc_item(hashzone, NULL,
885 		    UMA_ANYDOMAIN, M_WAITOK);
886 		hash->uh_hashsize = UMA_HASH_SIZE_INIT;
887 	}
888 	if (hash->uh_slab_hash) {
889 		bzero(hash->uh_slab_hash, alloc);
890 		hash->uh_hashmask = hash->uh_hashsize - 1;
891 		return (1);
892 	}
893 
894 	return (0);
895 }
896 
897 /*
898  * Expands the hash table for HASH zones.  This is done from zone_timeout
899  * to reduce collisions.  This must not be done in the regular allocation
900  * path, otherwise, we can recurse on the vm while allocating pages.
901  *
902  * Arguments:
903  *	oldhash  The hash you want to expand
904  *	newhash  The hash structure for the new table
905  *
906  * Returns:
907  *	Nothing
908  *
909  * Discussion:
910  */
911 static int
912 hash_expand(struct uma_hash *oldhash, struct uma_hash *newhash)
913 {
914 	uma_hash_slab_t slab;
915 	u_int hval;
916 	u_int idx;
917 
918 	if (!newhash->uh_slab_hash)
919 		return (0);
920 
921 	if (oldhash->uh_hashsize >= newhash->uh_hashsize)
922 		return (0);
923 
924 	/*
925 	 * I need to investigate hash algorithms for resizing without a
926 	 * full rehash.
927 	 */
928 
929 	for (idx = 0; idx < oldhash->uh_hashsize; idx++)
930 		while (!LIST_EMPTY(&oldhash->uh_slab_hash[idx])) {
931 			slab = LIST_FIRST(&oldhash->uh_slab_hash[idx]);
932 			LIST_REMOVE(slab, uhs_hlink);
933 			hval = UMA_HASH(newhash, slab->uhs_data);
934 			LIST_INSERT_HEAD(&newhash->uh_slab_hash[hval],
935 			    slab, uhs_hlink);
936 		}
937 
938 	return (1);
939 }
940 
941 /*
942  * Free the hash bucket to the appropriate backing store.
943  *
944  * Arguments:
945  *	slab_hash  The hash bucket we're freeing
946  *	hashsize   The number of entries in that hash bucket
947  *
948  * Returns:
949  *	Nothing
950  */
951 static void
952 hash_free(struct uma_hash *hash)
953 {
954 	if (hash->uh_slab_hash == NULL)
955 		return;
956 	if (hash->uh_hashsize == UMA_HASH_SIZE_INIT)
957 		zone_free_item(hashzone, hash->uh_slab_hash, NULL, SKIP_NONE);
958 	else
959 		free(hash->uh_slab_hash, M_UMAHASH);
960 }
961 
962 /*
963  * Frees all outstanding items in a bucket
964  *
965  * Arguments:
966  *	zone   The zone to free to, must be unlocked.
967  *	bucket The free/alloc bucket with items.
968  *
969  * Returns:
970  *	Nothing
971  */
972 
973 static void
974 bucket_drain(uma_zone_t zone, uma_bucket_t bucket)
975 {
976 	int i;
977 
978 	if (bucket == NULL || bucket->ub_cnt == 0)
979 		return;
980 
981 	if ((zone->uz_flags & UMA_ZONE_SMR) != 0 &&
982 	    bucket->ub_seq != SMR_SEQ_INVALID) {
983 		smr_wait(zone->uz_smr, bucket->ub_seq);
984 		bucket->ub_seq = SMR_SEQ_INVALID;
985 		for (i = 0; i < bucket->ub_cnt; i++)
986 			item_dtor(zone, bucket->ub_bucket[i],
987 			    zone->uz_size, NULL, SKIP_NONE);
988 	}
989 	if (zone->uz_fini)
990 		for (i = 0; i < bucket->ub_cnt; i++)
991 			zone->uz_fini(bucket->ub_bucket[i], zone->uz_size);
992 	zone->uz_release(zone->uz_arg, bucket->ub_bucket, bucket->ub_cnt);
993 	if (zone->uz_max_items > 0)
994 		zone_free_limit(zone, bucket->ub_cnt);
995 #ifdef INVARIANTS
996 	bzero(bucket->ub_bucket, sizeof(void *) * bucket->ub_cnt);
997 #endif
998 	bucket->ub_cnt = 0;
999 }
1000 
1001 /*
1002  * Drains the per cpu caches for a zone.
1003  *
1004  * NOTE: This may only be called while the zone is being torn down, and not
1005  * during normal operation.  This is necessary in order that we do not have
1006  * to migrate CPUs to drain the per-CPU caches.
1007  *
1008  * Arguments:
1009  *	zone     The zone to drain, must be unlocked.
1010  *
1011  * Returns:
1012  *	Nothing
1013  */
1014 static void
1015 cache_drain(uma_zone_t zone)
1016 {
1017 	uma_cache_t cache;
1018 	uma_bucket_t bucket;
1019 	smr_seq_t seq;
1020 	int cpu;
1021 
1022 	/*
1023 	 * XXX: It is safe to not lock the per-CPU caches, because we're
1024 	 * tearing down the zone anyway.  I.e., there will be no further use
1025 	 * of the caches at this point.
1026 	 *
1027 	 * XXX: It would good to be able to assert that the zone is being
1028 	 * torn down to prevent improper use of cache_drain().
1029 	 */
1030 	seq = SMR_SEQ_INVALID;
1031 	if ((zone->uz_flags & UMA_ZONE_SMR) != 0)
1032 		seq = smr_current(zone->uz_smr);
1033 	CPU_FOREACH(cpu) {
1034 		cache = &zone->uz_cpu[cpu];
1035 		bucket = cache_bucket_unload_alloc(cache);
1036 		if (bucket != NULL) {
1037 			bucket_drain(zone, bucket);
1038 			bucket_free(zone, bucket, NULL);
1039 		}
1040 		bucket = cache_bucket_unload_free(cache);
1041 		if (bucket != NULL) {
1042 			bucket->ub_seq = seq;
1043 			bucket_drain(zone, bucket);
1044 			bucket_free(zone, bucket, NULL);
1045 		}
1046 		bucket = cache_bucket_unload_cross(cache);
1047 		if (bucket != NULL) {
1048 			bucket->ub_seq = seq;
1049 			bucket_drain(zone, bucket);
1050 			bucket_free(zone, bucket, NULL);
1051 		}
1052 	}
1053 	bucket_cache_reclaim(zone, true);
1054 }
1055 
1056 static void
1057 cache_shrink(uma_zone_t zone, void *unused)
1058 {
1059 
1060 	if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
1061 		return;
1062 
1063 	ZONE_LOCK(zone);
1064 	zone->uz_bucket_size =
1065 	    (zone->uz_bucket_size_min + zone->uz_bucket_size) / 2;
1066 	ZONE_UNLOCK(zone);
1067 }
1068 
1069 static void
1070 cache_drain_safe_cpu(uma_zone_t zone, void *unused)
1071 {
1072 	uma_cache_t cache;
1073 	uma_bucket_t b1, b2, b3;
1074 	int domain;
1075 
1076 	if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
1077 		return;
1078 
1079 	b1 = b2 = b3 = NULL;
1080 	critical_enter();
1081 	if (zone->uz_flags & UMA_ZONE_FIRSTTOUCH)
1082 		domain = PCPU_GET(domain);
1083 	else
1084 		domain = 0;
1085 	cache = &zone->uz_cpu[curcpu];
1086 	b1 = cache_bucket_unload_alloc(cache);
1087 
1088 	/*
1089 	 * Don't flush SMR zone buckets.  This leaves the zone without a
1090 	 * bucket and forces every free to synchronize().
1091 	 */
1092 	if ((zone->uz_flags & UMA_ZONE_SMR) == 0) {
1093 		b2 = cache_bucket_unload_free(cache);
1094 		b3 = cache_bucket_unload_cross(cache);
1095 	}
1096 	critical_exit();
1097 
1098 	ZONE_LOCK(zone);
1099 	if (b1 != NULL && b1->ub_cnt != 0) {
1100 		zone_put_bucket(zone, &zone->uz_domain[domain], b1, false);
1101 		b1 = NULL;
1102 	}
1103 	if (b2 != NULL && b2->ub_cnt != 0) {
1104 		zone_put_bucket(zone, &zone->uz_domain[domain], b2, false);
1105 		b2 = NULL;
1106 	}
1107 	ZONE_UNLOCK(zone);
1108 
1109 	if (b1 != NULL)
1110 		bucket_free(zone, b1, NULL);
1111 	if (b2 != NULL)
1112 		bucket_free(zone, b2, NULL);
1113 	if (b3 != NULL) {
1114 		bucket_drain(zone, b3);
1115 		bucket_free(zone, b3, NULL);
1116 	}
1117 }
1118 
1119 /*
1120  * Safely drain per-CPU caches of a zone(s) to alloc bucket.
1121  * This is an expensive call because it needs to bind to all CPUs
1122  * one by one and enter a critical section on each of them in order
1123  * to safely access their cache buckets.
1124  * Zone lock must not be held on call this function.
1125  */
1126 static void
1127 pcpu_cache_drain_safe(uma_zone_t zone)
1128 {
1129 	int cpu;
1130 
1131 	/*
1132 	 * Polite bucket sizes shrinking was not enough, shrink aggressively.
1133 	 */
1134 	if (zone)
1135 		cache_shrink(zone, NULL);
1136 	else
1137 		zone_foreach(cache_shrink, NULL);
1138 
1139 	CPU_FOREACH(cpu) {
1140 		thread_lock(curthread);
1141 		sched_bind(curthread, cpu);
1142 		thread_unlock(curthread);
1143 
1144 		if (zone)
1145 			cache_drain_safe_cpu(zone, NULL);
1146 		else
1147 			zone_foreach(cache_drain_safe_cpu, NULL);
1148 	}
1149 	thread_lock(curthread);
1150 	sched_unbind(curthread);
1151 	thread_unlock(curthread);
1152 }
1153 
1154 /*
1155  * Reclaim cached buckets from a zone.  All buckets are reclaimed if the caller
1156  * requested a drain, otherwise the per-domain caches are trimmed to either
1157  * estimated working set size.
1158  */
1159 static void
1160 bucket_cache_reclaim(uma_zone_t zone, bool drain)
1161 {
1162 	uma_zone_domain_t zdom;
1163 	uma_bucket_t bucket;
1164 	long target, tofree;
1165 	int i;
1166 
1167 	for (i = 0; i < vm_ndomains; i++) {
1168 		/*
1169 		 * The cross bucket is partially filled and not part of
1170 		 * the item count.  Reclaim it individually here.
1171 		 */
1172 		zdom = &zone->uz_domain[i];
1173 		ZONE_CROSS_LOCK(zone);
1174 		bucket = zdom->uzd_cross;
1175 		zdom->uzd_cross = NULL;
1176 		ZONE_CROSS_UNLOCK(zone);
1177 		if (bucket != NULL) {
1178 			bucket_drain(zone, bucket);
1179 			bucket_free(zone, bucket, NULL);
1180 		}
1181 
1182 		/*
1183 		 * Shrink the zone bucket size to ensure that the per-CPU caches
1184 		 * don't grow too large.
1185 		 */
1186 		ZONE_LOCK(zone);
1187 		if (i == 0 && zone->uz_bucket_size > zone->uz_bucket_size_min)
1188 			zone->uz_bucket_size--;
1189 
1190 		/*
1191 		 * If we were asked to drain the zone, we are done only once
1192 		 * this bucket cache is empty.  Otherwise, we reclaim items in
1193 		 * excess of the zone's estimated working set size.  If the
1194 		 * difference nitems - imin is larger than the WSS estimate,
1195 		 * then the estimate will grow at the end of this interval and
1196 		 * we ignore the historical average.
1197 		 */
1198 		target = drain ? 0 : lmax(zdom->uzd_wss, zdom->uzd_nitems -
1199 		    zdom->uzd_imin);
1200 		while (zdom->uzd_nitems > target) {
1201 			bucket = STAILQ_FIRST(&zdom->uzd_buckets);
1202 			if (bucket == NULL)
1203 				break;
1204 			tofree = bucket->ub_cnt;
1205 			STAILQ_REMOVE_HEAD(&zdom->uzd_buckets, ub_link);
1206 			zdom->uzd_nitems -= tofree;
1207 			zone->uz_bkt_count -= tofree;
1208 
1209 			/*
1210 			 * Shift the bounds of the current WSS interval to avoid
1211 			 * perturbing the estimate.
1212 			 */
1213 			zdom->uzd_imax -= lmin(zdom->uzd_imax, tofree);
1214 			zdom->uzd_imin -= lmin(zdom->uzd_imin, tofree);
1215 
1216 			ZONE_UNLOCK(zone);
1217 			bucket_drain(zone, bucket);
1218 			bucket_free(zone, bucket, NULL);
1219 			ZONE_LOCK(zone);
1220 		}
1221 		ZONE_UNLOCK(zone);
1222 	}
1223 }
1224 
1225 static void
1226 keg_free_slab(uma_keg_t keg, uma_slab_t slab, int start)
1227 {
1228 	uint8_t *mem;
1229 	int i;
1230 	uint8_t flags;
1231 
1232 	CTR4(KTR_UMA, "keg_free_slab keg %s(%p) slab %p, returning %d bytes",
1233 	    keg->uk_name, keg, slab, PAGE_SIZE * keg->uk_ppera);
1234 
1235 	mem = slab_data(slab, keg);
1236 	flags = slab->us_flags;
1237 	i = start;
1238 	if (keg->uk_fini != NULL) {
1239 		for (i--; i > -1; i--)
1240 #ifdef INVARIANTS
1241 		/*
1242 		 * trash_fini implies that dtor was trash_dtor. trash_fini
1243 		 * would check that memory hasn't been modified since free,
1244 		 * which executed trash_dtor.
1245 		 * That's why we need to run uma_dbg_kskip() check here,
1246 		 * albeit we don't make skip check for other init/fini
1247 		 * invocations.
1248 		 */
1249 		if (!uma_dbg_kskip(keg, slab_item(slab, keg, i)) ||
1250 		    keg->uk_fini != trash_fini)
1251 #endif
1252 			keg->uk_fini(slab_item(slab, keg, i), keg->uk_size);
1253 	}
1254 	if (keg->uk_flags & UMA_ZFLAG_OFFPAGE)
1255 		zone_free_item(slabzone(keg->uk_ipers), slab_tohashslab(slab),
1256 		    NULL, SKIP_NONE);
1257 	keg->uk_freef(mem, PAGE_SIZE * keg->uk_ppera, flags);
1258 	uma_total_dec(PAGE_SIZE * keg->uk_ppera);
1259 }
1260 
1261 /*
1262  * Frees pages from a keg back to the system.  This is done on demand from
1263  * the pageout daemon.
1264  *
1265  * Returns nothing.
1266  */
1267 static void
1268 keg_drain(uma_keg_t keg)
1269 {
1270 	struct slabhead freeslabs;
1271 	uma_domain_t dom;
1272 	uma_slab_t slab, tmp;
1273 	int i, n;
1274 
1275 	if (keg->uk_flags & UMA_ZONE_NOFREE || keg->uk_freef == NULL)
1276 		return;
1277 
1278 	for (i = 0; i < vm_ndomains; i++) {
1279 		CTR4(KTR_UMA, "keg_drain %s(%p) domain %d free items: %u",
1280 		    keg->uk_name, keg, i, dom->ud_free_items);
1281 		dom = &keg->uk_domain[i];
1282 		LIST_INIT(&freeslabs);
1283 
1284 		KEG_LOCK(keg, i);
1285 		if ((keg->uk_flags & UMA_ZFLAG_HASH) != 0) {
1286 			LIST_FOREACH(slab, &dom->ud_free_slab, us_link)
1287 				UMA_HASH_REMOVE(&keg->uk_hash, slab);
1288 		}
1289 		n = dom->ud_free_slabs;
1290 		LIST_SWAP(&freeslabs, &dom->ud_free_slab, uma_slab, us_link);
1291 		dom->ud_free_slabs = 0;
1292 		dom->ud_free_items -= n * keg->uk_ipers;
1293 		dom->ud_pages -= n * keg->uk_ppera;
1294 		KEG_UNLOCK(keg, i);
1295 
1296 		LIST_FOREACH_SAFE(slab, &freeslabs, us_link, tmp)
1297 			keg_free_slab(keg, slab, keg->uk_ipers);
1298 	}
1299 }
1300 
1301 static void
1302 zone_reclaim(uma_zone_t zone, int waitok, bool drain)
1303 {
1304 
1305 	/*
1306 	 * Set draining to interlock with zone_dtor() so we can release our
1307 	 * locks as we go.  Only dtor() should do a WAITOK call since it
1308 	 * is the only call that knows the structure will still be available
1309 	 * when it wakes up.
1310 	 */
1311 	ZONE_LOCK(zone);
1312 	while (zone->uz_flags & UMA_ZFLAG_RECLAIMING) {
1313 		if (waitok == M_NOWAIT)
1314 			goto out;
1315 		msleep(zone, &zone->uz_lock, PVM, "zonedrain", 1);
1316 	}
1317 	zone->uz_flags |= UMA_ZFLAG_RECLAIMING;
1318 	ZONE_UNLOCK(zone);
1319 	bucket_cache_reclaim(zone, drain);
1320 
1321 	/*
1322 	 * The DRAINING flag protects us from being freed while
1323 	 * we're running.  Normally the uma_rwlock would protect us but we
1324 	 * must be able to release and acquire the right lock for each keg.
1325 	 */
1326 	if ((zone->uz_flags & UMA_ZFLAG_CACHE) == 0)
1327 		keg_drain(zone->uz_keg);
1328 	ZONE_LOCK(zone);
1329 	zone->uz_flags &= ~UMA_ZFLAG_RECLAIMING;
1330 	wakeup(zone);
1331 out:
1332 	ZONE_UNLOCK(zone);
1333 }
1334 
1335 static void
1336 zone_drain(uma_zone_t zone, void *unused)
1337 {
1338 
1339 	zone_reclaim(zone, M_NOWAIT, true);
1340 }
1341 
1342 static void
1343 zone_trim(uma_zone_t zone, void *unused)
1344 {
1345 
1346 	zone_reclaim(zone, M_NOWAIT, false);
1347 }
1348 
1349 /*
1350  * Allocate a new slab for a keg and inserts it into the partial slab list.
1351  * The keg should be unlocked on entry.  If the allocation succeeds it will
1352  * be locked on return.
1353  *
1354  * Arguments:
1355  *	flags   Wait flags for the item initialization routine
1356  *	aflags  Wait flags for the slab allocation
1357  *
1358  * Returns:
1359  *	The slab that was allocated or NULL if there is no memory and the
1360  *	caller specified M_NOWAIT.
1361  */
1362 static uma_slab_t
1363 keg_alloc_slab(uma_keg_t keg, uma_zone_t zone, int domain, int flags,
1364     int aflags)
1365 {
1366 	uma_domain_t dom;
1367 	uma_alloc allocf;
1368 	uma_slab_t slab;
1369 	unsigned long size;
1370 	uint8_t *mem;
1371 	uint8_t sflags;
1372 	int i;
1373 
1374 	KASSERT(domain >= 0 && domain < vm_ndomains,
1375 	    ("keg_alloc_slab: domain %d out of range", domain));
1376 
1377 	allocf = keg->uk_allocf;
1378 	slab = NULL;
1379 	mem = NULL;
1380 	if (keg->uk_flags & UMA_ZFLAG_OFFPAGE) {
1381 		uma_hash_slab_t hslab;
1382 		hslab = zone_alloc_item(slabzone(keg->uk_ipers), NULL,
1383 		    domain, aflags);
1384 		if (hslab == NULL)
1385 			goto fail;
1386 		slab = &hslab->uhs_slab;
1387 	}
1388 
1389 	/*
1390 	 * This reproduces the old vm_zone behavior of zero filling pages the
1391 	 * first time they are added to a zone.
1392 	 *
1393 	 * Malloced items are zeroed in uma_zalloc.
1394 	 */
1395 
1396 	if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
1397 		aflags |= M_ZERO;
1398 	else
1399 		aflags &= ~M_ZERO;
1400 
1401 	if (keg->uk_flags & UMA_ZONE_NODUMP)
1402 		aflags |= M_NODUMP;
1403 
1404 	/* zone is passed for legacy reasons. */
1405 	size = keg->uk_ppera * PAGE_SIZE;
1406 	mem = allocf(zone, size, domain, &sflags, aflags);
1407 	if (mem == NULL) {
1408 		if (keg->uk_flags & UMA_ZFLAG_OFFPAGE)
1409 			zone_free_item(slabzone(keg->uk_ipers),
1410 			    slab_tohashslab(slab), NULL, SKIP_NONE);
1411 		goto fail;
1412 	}
1413 	uma_total_inc(size);
1414 
1415 	/* For HASH zones all pages go to the same uma_domain. */
1416 	if ((keg->uk_flags & UMA_ZFLAG_HASH) != 0)
1417 		domain = 0;
1418 
1419 	/* Point the slab into the allocated memory */
1420 	if (!(keg->uk_flags & UMA_ZFLAG_OFFPAGE))
1421 		slab = (uma_slab_t )(mem + keg->uk_pgoff);
1422 	else
1423 		slab_tohashslab(slab)->uhs_data = mem;
1424 
1425 	if (keg->uk_flags & UMA_ZFLAG_VTOSLAB)
1426 		for (i = 0; i < keg->uk_ppera; i++)
1427 			vsetzoneslab((vm_offset_t)mem + (i * PAGE_SIZE),
1428 			    zone, slab);
1429 
1430 	slab->us_freecount = keg->uk_ipers;
1431 	slab->us_flags = sflags;
1432 	slab->us_domain = domain;
1433 
1434 	BIT_FILL(keg->uk_ipers, &slab->us_free);
1435 #ifdef INVARIANTS
1436 	BIT_ZERO(keg->uk_ipers, slab_dbg_bits(slab, keg));
1437 #endif
1438 
1439 	if (keg->uk_init != NULL) {
1440 		for (i = 0; i < keg->uk_ipers; i++)
1441 			if (keg->uk_init(slab_item(slab, keg, i),
1442 			    keg->uk_size, flags) != 0)
1443 				break;
1444 		if (i != keg->uk_ipers) {
1445 			keg_free_slab(keg, slab, i);
1446 			goto fail;
1447 		}
1448 	}
1449 	KEG_LOCK(keg, domain);
1450 
1451 	CTR3(KTR_UMA, "keg_alloc_slab: allocated slab %p for %s(%p)",
1452 	    slab, keg->uk_name, keg);
1453 
1454 	if (keg->uk_flags & UMA_ZFLAG_HASH)
1455 		UMA_HASH_INSERT(&keg->uk_hash, slab, mem);
1456 
1457 	/*
1458 	 * If we got a slab here it's safe to mark it partially used
1459 	 * and return.  We assume that the caller is going to remove
1460 	 * at least one item.
1461 	 */
1462 	dom = &keg->uk_domain[domain];
1463 	LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
1464 	dom->ud_pages += keg->uk_ppera;
1465 	dom->ud_free_items += keg->uk_ipers;
1466 
1467 	return (slab);
1468 
1469 fail:
1470 	return (NULL);
1471 }
1472 
1473 /*
1474  * This function is intended to be used early on in place of page_alloc() so
1475  * that we may use the boot time page cache to satisfy allocations before
1476  * the VM is ready.
1477  */
1478 static void *
1479 startup_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
1480     int wait)
1481 {
1482 	vm_paddr_t pa;
1483 	vm_page_t m;
1484 	void *mem;
1485 	int pages;
1486 	int i;
1487 
1488 	pages = howmany(bytes, PAGE_SIZE);
1489 	KASSERT(pages > 0, ("%s can't reserve 0 pages", __func__));
1490 
1491 	*pflag = UMA_SLAB_BOOT;
1492 	m = vm_page_alloc_contig_domain(NULL, 0, domain,
1493 	    malloc2vm_flags(wait) | VM_ALLOC_NOOBJ | VM_ALLOC_WIRED, pages,
1494 	    (vm_paddr_t)0, ~(vm_paddr_t)0, 1, 0, VM_MEMATTR_DEFAULT);
1495 	if (m == NULL)
1496 		return (NULL);
1497 
1498 	pa = VM_PAGE_TO_PHYS(m);
1499 	for (i = 0; i < pages; i++, pa += PAGE_SIZE) {
1500 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) || \
1501     defined(__riscv) || defined(__powerpc64__)
1502 		if ((wait & M_NODUMP) == 0)
1503 			dump_add_page(pa);
1504 #endif
1505 	}
1506 	/* Allocate KVA and indirectly advance bootmem. */
1507 	mem = (void *)pmap_map(&bootmem, m->phys_addr,
1508 	    m->phys_addr + (pages * PAGE_SIZE), VM_PROT_READ | VM_PROT_WRITE);
1509         if ((wait & M_ZERO) != 0)
1510                 bzero(mem, pages * PAGE_SIZE);
1511 
1512         return (mem);
1513 }
1514 
1515 static void
1516 startup_free(void *mem, vm_size_t bytes)
1517 {
1518 	vm_offset_t va;
1519 	vm_page_t m;
1520 
1521 	va = (vm_offset_t)mem;
1522 	m = PHYS_TO_VM_PAGE(pmap_kextract(va));
1523 	pmap_remove(kernel_pmap, va, va + bytes);
1524 	for (; bytes != 0; bytes -= PAGE_SIZE, m++) {
1525 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) || \
1526     defined(__riscv) || defined(__powerpc64__)
1527 		dump_drop_page(VM_PAGE_TO_PHYS(m));
1528 #endif
1529 		vm_page_unwire_noq(m);
1530 		vm_page_free(m);
1531 	}
1532 }
1533 
1534 /*
1535  * Allocates a number of pages from the system
1536  *
1537  * Arguments:
1538  *	bytes  The number of bytes requested
1539  *	wait  Shall we wait?
1540  *
1541  * Returns:
1542  *	A pointer to the alloced memory or possibly
1543  *	NULL if M_NOWAIT is set.
1544  */
1545 static void *
1546 page_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
1547     int wait)
1548 {
1549 	void *p;	/* Returned page */
1550 
1551 	*pflag = UMA_SLAB_KERNEL;
1552 	p = (void *)kmem_malloc_domainset(DOMAINSET_FIXED(domain), bytes, wait);
1553 
1554 	return (p);
1555 }
1556 
1557 static void *
1558 pcpu_page_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
1559     int wait)
1560 {
1561 	struct pglist alloctail;
1562 	vm_offset_t addr, zkva;
1563 	int cpu, flags;
1564 	vm_page_t p, p_next;
1565 #ifdef NUMA
1566 	struct pcpu *pc;
1567 #endif
1568 
1569 	MPASS(bytes == (mp_maxid + 1) * PAGE_SIZE);
1570 
1571 	TAILQ_INIT(&alloctail);
1572 	flags = VM_ALLOC_SYSTEM | VM_ALLOC_WIRED | VM_ALLOC_NOOBJ |
1573 	    malloc2vm_flags(wait);
1574 	*pflag = UMA_SLAB_KERNEL;
1575 	for (cpu = 0; cpu <= mp_maxid; cpu++) {
1576 		if (CPU_ABSENT(cpu)) {
1577 			p = vm_page_alloc(NULL, 0, flags);
1578 		} else {
1579 #ifndef NUMA
1580 			p = vm_page_alloc(NULL, 0, flags);
1581 #else
1582 			pc = pcpu_find(cpu);
1583 			if (__predict_false(VM_DOMAIN_EMPTY(pc->pc_domain)))
1584 				p = NULL;
1585 			else
1586 				p = vm_page_alloc_domain(NULL, 0,
1587 				    pc->pc_domain, flags);
1588 			if (__predict_false(p == NULL))
1589 				p = vm_page_alloc(NULL, 0, flags);
1590 #endif
1591 		}
1592 		if (__predict_false(p == NULL))
1593 			goto fail;
1594 		TAILQ_INSERT_TAIL(&alloctail, p, listq);
1595 	}
1596 	if ((addr = kva_alloc(bytes)) == 0)
1597 		goto fail;
1598 	zkva = addr;
1599 	TAILQ_FOREACH(p, &alloctail, listq) {
1600 		pmap_qenter(zkva, &p, 1);
1601 		zkva += PAGE_SIZE;
1602 	}
1603 	return ((void*)addr);
1604 fail:
1605 	TAILQ_FOREACH_SAFE(p, &alloctail, listq, p_next) {
1606 		vm_page_unwire_noq(p);
1607 		vm_page_free(p);
1608 	}
1609 	return (NULL);
1610 }
1611 
1612 /*
1613  * Allocates a number of pages from within an object
1614  *
1615  * Arguments:
1616  *	bytes  The number of bytes requested
1617  *	wait   Shall we wait?
1618  *
1619  * Returns:
1620  *	A pointer to the alloced memory or possibly
1621  *	NULL if M_NOWAIT is set.
1622  */
1623 static void *
1624 noobj_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *flags,
1625     int wait)
1626 {
1627 	TAILQ_HEAD(, vm_page) alloctail;
1628 	u_long npages;
1629 	vm_offset_t retkva, zkva;
1630 	vm_page_t p, p_next;
1631 	uma_keg_t keg;
1632 
1633 	TAILQ_INIT(&alloctail);
1634 	keg = zone->uz_keg;
1635 
1636 	npages = howmany(bytes, PAGE_SIZE);
1637 	while (npages > 0) {
1638 		p = vm_page_alloc_domain(NULL, 0, domain, VM_ALLOC_INTERRUPT |
1639 		    VM_ALLOC_WIRED | VM_ALLOC_NOOBJ |
1640 		    ((wait & M_WAITOK) != 0 ? VM_ALLOC_WAITOK :
1641 		    VM_ALLOC_NOWAIT));
1642 		if (p != NULL) {
1643 			/*
1644 			 * Since the page does not belong to an object, its
1645 			 * listq is unused.
1646 			 */
1647 			TAILQ_INSERT_TAIL(&alloctail, p, listq);
1648 			npages--;
1649 			continue;
1650 		}
1651 		/*
1652 		 * Page allocation failed, free intermediate pages and
1653 		 * exit.
1654 		 */
1655 		TAILQ_FOREACH_SAFE(p, &alloctail, listq, p_next) {
1656 			vm_page_unwire_noq(p);
1657 			vm_page_free(p);
1658 		}
1659 		return (NULL);
1660 	}
1661 	*flags = UMA_SLAB_PRIV;
1662 	zkva = keg->uk_kva +
1663 	    atomic_fetchadd_long(&keg->uk_offset, round_page(bytes));
1664 	retkva = zkva;
1665 	TAILQ_FOREACH(p, &alloctail, listq) {
1666 		pmap_qenter(zkva, &p, 1);
1667 		zkva += PAGE_SIZE;
1668 	}
1669 
1670 	return ((void *)retkva);
1671 }
1672 
1673 /*
1674  * Allocate physically contiguous pages.
1675  */
1676 static void *
1677 contig_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
1678     int wait)
1679 {
1680 
1681 	*pflag = UMA_SLAB_KERNEL;
1682 	return ((void *)kmem_alloc_contig_domainset(DOMAINSET_FIXED(domain),
1683 	    bytes, wait, 0, ~(vm_paddr_t)0, 1, 0, VM_MEMATTR_DEFAULT));
1684 }
1685 
1686 /*
1687  * Frees a number of pages to the system
1688  *
1689  * Arguments:
1690  *	mem   A pointer to the memory to be freed
1691  *	size  The size of the memory being freed
1692  *	flags The original p->us_flags field
1693  *
1694  * Returns:
1695  *	Nothing
1696  */
1697 static void
1698 page_free(void *mem, vm_size_t size, uint8_t flags)
1699 {
1700 
1701 	if ((flags & UMA_SLAB_BOOT) != 0) {
1702 		startup_free(mem, size);
1703 		return;
1704 	}
1705 
1706 	KASSERT((flags & UMA_SLAB_KERNEL) != 0,
1707 	    ("UMA: page_free used with invalid flags %x", flags));
1708 
1709 	kmem_free((vm_offset_t)mem, size);
1710 }
1711 
1712 /*
1713  * Frees pcpu zone allocations
1714  *
1715  * Arguments:
1716  *	mem   A pointer to the memory to be freed
1717  *	size  The size of the memory being freed
1718  *	flags The original p->us_flags field
1719  *
1720  * Returns:
1721  *	Nothing
1722  */
1723 static void
1724 pcpu_page_free(void *mem, vm_size_t size, uint8_t flags)
1725 {
1726 	vm_offset_t sva, curva;
1727 	vm_paddr_t paddr;
1728 	vm_page_t m;
1729 
1730 	MPASS(size == (mp_maxid+1)*PAGE_SIZE);
1731 
1732 	if ((flags & UMA_SLAB_BOOT) != 0) {
1733 		startup_free(mem, size);
1734 		return;
1735 	}
1736 
1737 	sva = (vm_offset_t)mem;
1738 	for (curva = sva; curva < sva + size; curva += PAGE_SIZE) {
1739 		paddr = pmap_kextract(curva);
1740 		m = PHYS_TO_VM_PAGE(paddr);
1741 		vm_page_unwire_noq(m);
1742 		vm_page_free(m);
1743 	}
1744 	pmap_qremove(sva, size >> PAGE_SHIFT);
1745 	kva_free(sva, size);
1746 }
1747 
1748 
1749 /*
1750  * Zero fill initializer
1751  *
1752  * Arguments/Returns follow uma_init specifications
1753  */
1754 static int
1755 zero_init(void *mem, int size, int flags)
1756 {
1757 	bzero(mem, size);
1758 	return (0);
1759 }
1760 
1761 #ifdef INVARIANTS
1762 struct noslabbits *
1763 slab_dbg_bits(uma_slab_t slab, uma_keg_t keg)
1764 {
1765 
1766 	return ((void *)((char *)&slab->us_free + BITSET_SIZE(keg->uk_ipers)));
1767 }
1768 #endif
1769 
1770 /*
1771  * Actual size of embedded struct slab (!OFFPAGE).
1772  */
1773 size_t
1774 slab_sizeof(int nitems)
1775 {
1776 	size_t s;
1777 
1778 	s = sizeof(struct uma_slab) + BITSET_SIZE(nitems) * SLAB_BITSETS;
1779 	return (roundup(s, UMA_ALIGN_PTR + 1));
1780 }
1781 
1782 /*
1783  * Size of memory for embedded slabs (!OFFPAGE).
1784  */
1785 size_t
1786 slab_space(int nitems)
1787 {
1788 	return (UMA_SLAB_SIZE - slab_sizeof(nitems));
1789 }
1790 
1791 #define	UMA_FIXPT_SHIFT	31
1792 #define	UMA_FRAC_FIXPT(n, d)						\
1793 	((uint32_t)(((uint64_t)(n) << UMA_FIXPT_SHIFT) / (d)))
1794 #define	UMA_FIXPT_PCT(f)						\
1795 	((u_int)(((uint64_t)100 * (f)) >> UMA_FIXPT_SHIFT))
1796 #define	UMA_PCT_FIXPT(pct)	UMA_FRAC_FIXPT((pct), 100)
1797 #define	UMA_MIN_EFF	UMA_PCT_FIXPT(100 - UMA_MAX_WASTE)
1798 
1799 /*
1800  * Compute the number of items that will fit in a slab.  If hdr is true, the
1801  * item count may be limited to provide space in the slab for an inline slab
1802  * header.  Otherwise, all slab space will be provided for item storage.
1803  */
1804 static u_int
1805 slab_ipers_hdr(u_int size, u_int rsize, u_int slabsize, bool hdr)
1806 {
1807 	u_int ipers;
1808 	u_int padpi;
1809 
1810 	/* The padding between items is not needed after the last item. */
1811 	padpi = rsize - size;
1812 
1813 	if (hdr) {
1814 		/*
1815 		 * Start with the maximum item count and remove items until
1816 		 * the slab header first alongside the allocatable memory.
1817 		 */
1818 		for (ipers = MIN(SLAB_MAX_SETSIZE,
1819 		    (slabsize + padpi - slab_sizeof(1)) / rsize);
1820 		    ipers > 0 &&
1821 		    ipers * rsize - padpi + slab_sizeof(ipers) > slabsize;
1822 		    ipers--)
1823 			continue;
1824 	} else {
1825 		ipers = MIN((slabsize + padpi) / rsize, SLAB_MAX_SETSIZE);
1826 	}
1827 
1828 	return (ipers);
1829 }
1830 
1831 /*
1832  * Compute the number of items that will fit in a slab for a startup zone.
1833  */
1834 int
1835 slab_ipers(size_t size, int align)
1836 {
1837 	int rsize;
1838 
1839 	rsize = roundup(size, align + 1); /* Assume no CACHESPREAD */
1840 	return (slab_ipers_hdr(size, rsize, UMA_SLAB_SIZE, true));
1841 }
1842 
1843 struct keg_layout_result {
1844 	u_int format;
1845 	u_int slabsize;
1846 	u_int ipers;
1847 	u_int eff;
1848 };
1849 
1850 static void
1851 keg_layout_one(uma_keg_t keg, u_int rsize, u_int slabsize, u_int fmt,
1852     struct keg_layout_result *kl)
1853 {
1854 	u_int total;
1855 
1856 	kl->format = fmt;
1857 	kl->slabsize = slabsize;
1858 
1859 	/* Handle INTERNAL as inline with an extra page. */
1860 	if ((fmt & UMA_ZFLAG_INTERNAL) != 0) {
1861 		kl->format &= ~UMA_ZFLAG_INTERNAL;
1862 		kl->slabsize += PAGE_SIZE;
1863 	}
1864 
1865 	kl->ipers = slab_ipers_hdr(keg->uk_size, rsize, kl->slabsize,
1866 	    (fmt & UMA_ZFLAG_OFFPAGE) == 0);
1867 
1868 	/* Account for memory used by an offpage slab header. */
1869 	total = kl->slabsize;
1870 	if ((fmt & UMA_ZFLAG_OFFPAGE) != 0)
1871 		total += slabzone(kl->ipers)->uz_keg->uk_rsize;
1872 
1873 	kl->eff = UMA_FRAC_FIXPT(kl->ipers * rsize, total);
1874 }
1875 
1876 /*
1877  * Determine the format of a uma keg.  This determines where the slab header
1878  * will be placed (inline or offpage) and calculates ipers, rsize, and ppera.
1879  *
1880  * Arguments
1881  *	keg  The zone we should initialize
1882  *
1883  * Returns
1884  *	Nothing
1885  */
1886 static void
1887 keg_layout(uma_keg_t keg)
1888 {
1889 	struct keg_layout_result kl = {}, kl_tmp;
1890 	u_int fmts[2];
1891 	u_int alignsize;
1892 	u_int nfmt;
1893 	u_int pages;
1894 	u_int rsize;
1895 	u_int slabsize;
1896 	u_int i, j;
1897 
1898 	KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0 ||
1899 	    (keg->uk_size <= UMA_PCPU_ALLOC_SIZE &&
1900 	     (keg->uk_flags & UMA_ZONE_CACHESPREAD) == 0),
1901 	    ("%s: cannot configure for PCPU: keg=%s, size=%u, flags=0x%b",
1902 	     __func__, keg->uk_name, keg->uk_size, keg->uk_flags,
1903 	     PRINT_UMA_ZFLAGS));
1904 	KASSERT((keg->uk_flags & (UMA_ZFLAG_INTERNAL | UMA_ZONE_VM)) == 0 ||
1905 	    (keg->uk_flags & (UMA_ZONE_NOTOUCH | UMA_ZONE_PCPU)) == 0,
1906 	    ("%s: incompatible flags 0x%b", __func__, keg->uk_flags,
1907 	     PRINT_UMA_ZFLAGS));
1908 
1909 	alignsize = keg->uk_align + 1;
1910 
1911 	/*
1912 	 * Calculate the size of each allocation (rsize) according to
1913 	 * alignment.  If the requested size is smaller than we have
1914 	 * allocation bits for we round it up.
1915 	 */
1916 	rsize = MAX(keg->uk_size, UMA_SMALLEST_UNIT);
1917 	rsize = roundup2(rsize, alignsize);
1918 
1919 	if ((keg->uk_flags & UMA_ZONE_CACHESPREAD) != 0) {
1920 		/*
1921 		 * We want one item to start on every align boundary in a page.
1922 		 * To do this we will span pages.  We will also extend the item
1923 		 * by the size of align if it is an even multiple of align.
1924 		 * Otherwise, it would fall on the same boundary every time.
1925 		 */
1926 		if ((rsize & alignsize) == 0)
1927 			rsize += alignsize;
1928 		slabsize = rsize * (PAGE_SIZE / alignsize);
1929 		slabsize = MIN(slabsize, rsize * SLAB_MAX_SETSIZE);
1930 		slabsize = MIN(slabsize, UMA_CACHESPREAD_MAX_SIZE);
1931 		slabsize = round_page(slabsize);
1932 	} else {
1933 		/*
1934 		 * Start with a slab size of as many pages as it takes to
1935 		 * represent a single item.  We will try to fit as many
1936 		 * additional items into the slab as possible.
1937 		 */
1938 		slabsize = round_page(keg->uk_size);
1939 	}
1940 
1941 	/* Build a list of all of the available formats for this keg. */
1942 	nfmt = 0;
1943 
1944 	/* Evaluate an inline slab layout. */
1945 	if ((keg->uk_flags & (UMA_ZONE_NOTOUCH | UMA_ZONE_PCPU)) == 0)
1946 		fmts[nfmt++] = 0;
1947 
1948 	/* TODO: vm_page-embedded slab. */
1949 
1950 	/*
1951 	 * We can't do OFFPAGE if we're internal or if we've been
1952 	 * asked to not go to the VM for buckets.  If we do this we
1953 	 * may end up going to the VM for slabs which we do not want
1954 	 * to do if we're UMA_ZONE_VM, which clearly forbids it.
1955 	 * In those cases, evaluate a pseudo-format called INTERNAL
1956 	 * which has an inline slab header and one extra page to
1957 	 * guarantee that it fits.
1958 	 *
1959 	 * Otherwise, see if using an OFFPAGE slab will improve our
1960 	 * efficiency.
1961 	 */
1962 	if ((keg->uk_flags & (UMA_ZFLAG_INTERNAL | UMA_ZONE_VM)) != 0)
1963 		fmts[nfmt++] = UMA_ZFLAG_INTERNAL;
1964 	else
1965 		fmts[nfmt++] = UMA_ZFLAG_OFFPAGE;
1966 
1967 	/*
1968 	 * Choose a slab size and format which satisfy the minimum efficiency.
1969 	 * Prefer the smallest slab size that meets the constraints.
1970 	 *
1971 	 * Start with a minimum slab size, to accommodate CACHESPREAD.  Then,
1972 	 * for small items (up to PAGE_SIZE), the iteration increment is one
1973 	 * page; and for large items, the increment is one item.
1974 	 */
1975 	i = (slabsize + rsize - keg->uk_size) / MAX(PAGE_SIZE, rsize);
1976 	KASSERT(i >= 1, ("keg %s(%p) flags=0x%b slabsize=%u, rsize=%u, i=%u",
1977 	    keg->uk_name, keg, keg->uk_flags, PRINT_UMA_ZFLAGS, slabsize,
1978 	    rsize, i));
1979 	for ( ; ; i++) {
1980 		slabsize = (rsize <= PAGE_SIZE) ? ptoa(i) :
1981 		    round_page(rsize * (i - 1) + keg->uk_size);
1982 
1983 		for (j = 0; j < nfmt; j++) {
1984 			/* Only if we have no viable format yet. */
1985 			if ((fmts[j] & UMA_ZFLAG_INTERNAL) != 0 &&
1986 			    kl.ipers > 0)
1987 				continue;
1988 
1989 			keg_layout_one(keg, rsize, slabsize, fmts[j], &kl_tmp);
1990 			if (kl_tmp.eff <= kl.eff)
1991 				continue;
1992 
1993 			kl = kl_tmp;
1994 
1995 			CTR6(KTR_UMA, "keg %s layout: format %#x "
1996 			    "(ipers %u * rsize %u) / slabsize %#x = %u%% eff",
1997 			    keg->uk_name, kl.format, kl.ipers, rsize,
1998 			    kl.slabsize, UMA_FIXPT_PCT(kl.eff));
1999 
2000 			/* Stop when we reach the minimum efficiency. */
2001 			if (kl.eff >= UMA_MIN_EFF)
2002 				break;
2003 		}
2004 
2005 		if (kl.eff >= UMA_MIN_EFF || !multipage_slabs ||
2006 		    slabsize >= SLAB_MAX_SETSIZE * rsize ||
2007 		    (keg->uk_flags & (UMA_ZONE_PCPU | UMA_ZONE_CONTIG)) != 0)
2008 			break;
2009 	}
2010 
2011 	pages = atop(kl.slabsize);
2012 	if ((keg->uk_flags & UMA_ZONE_PCPU) != 0)
2013 		pages *= mp_maxid + 1;
2014 
2015 	keg->uk_rsize = rsize;
2016 	keg->uk_ipers = kl.ipers;
2017 	keg->uk_ppera = pages;
2018 	keg->uk_flags |= kl.format;
2019 
2020 	/*
2021 	 * How do we find the slab header if it is offpage or if not all item
2022 	 * start addresses are in the same page?  We could solve the latter
2023 	 * case with vaddr alignment, but we don't.
2024 	 */
2025 	if ((keg->uk_flags & UMA_ZFLAG_OFFPAGE) != 0 ||
2026 	    (keg->uk_ipers - 1) * rsize >= PAGE_SIZE) {
2027 		if ((keg->uk_flags & UMA_ZONE_NOTPAGE) != 0)
2028 			keg->uk_flags |= UMA_ZFLAG_HASH;
2029 		else
2030 			keg->uk_flags |= UMA_ZFLAG_VTOSLAB;
2031 	}
2032 
2033 	CTR6(KTR_UMA, "%s: keg=%s, flags=%#x, rsize=%u, ipers=%u, ppera=%u",
2034 	    __func__, keg->uk_name, keg->uk_flags, rsize, keg->uk_ipers,
2035 	    pages);
2036 	KASSERT(keg->uk_ipers > 0 && keg->uk_ipers <= SLAB_MAX_SETSIZE,
2037 	    ("%s: keg=%s, flags=0x%b, rsize=%u, ipers=%u, ppera=%u", __func__,
2038 	     keg->uk_name, keg->uk_flags, PRINT_UMA_ZFLAGS, rsize,
2039 	     keg->uk_ipers, pages));
2040 }
2041 
2042 /*
2043  * Keg header ctor.  This initializes all fields, locks, etc.  And inserts
2044  * the keg onto the global keg list.
2045  *
2046  * Arguments/Returns follow uma_ctor specifications
2047  *	udata  Actually uma_kctor_args
2048  */
2049 static int
2050 keg_ctor(void *mem, int size, void *udata, int flags)
2051 {
2052 	struct uma_kctor_args *arg = udata;
2053 	uma_keg_t keg = mem;
2054 	uma_zone_t zone;
2055 	int i;
2056 
2057 	bzero(keg, size);
2058 	keg->uk_size = arg->size;
2059 	keg->uk_init = arg->uminit;
2060 	keg->uk_fini = arg->fini;
2061 	keg->uk_align = arg->align;
2062 	keg->uk_reserve = 0;
2063 	keg->uk_flags = arg->flags;
2064 
2065 	/*
2066 	 * We use a global round-robin policy by default.  Zones with
2067 	 * UMA_ZONE_FIRSTTOUCH set will use first-touch instead, in which
2068 	 * case the iterator is never run.
2069 	 */
2070 	keg->uk_dr.dr_policy = DOMAINSET_RR();
2071 	keg->uk_dr.dr_iter = 0;
2072 
2073 	/*
2074 	 * The master zone is passed to us at keg-creation time.
2075 	 */
2076 	zone = arg->zone;
2077 	keg->uk_name = zone->uz_name;
2078 
2079 	if (arg->flags & UMA_ZONE_ZINIT)
2080 		keg->uk_init = zero_init;
2081 
2082 	if (arg->flags & UMA_ZONE_MALLOC)
2083 		keg->uk_flags |= UMA_ZFLAG_VTOSLAB;
2084 
2085 #ifndef SMP
2086 	keg->uk_flags &= ~UMA_ZONE_PCPU;
2087 #endif
2088 
2089 	keg_layout(keg);
2090 
2091 	/*
2092 	 * Use a first-touch NUMA policy for all kegs that pmap_extract()
2093 	 * will work on with the exception of critical VM structures
2094 	 * necessary for paging.
2095 	 *
2096 	 * Zones may override the default by specifying either.
2097 	 */
2098 #ifdef NUMA
2099 	if ((keg->uk_flags &
2100 	    (UMA_ZFLAG_HASH | UMA_ZONE_VM | UMA_ZONE_ROUNDROBIN)) == 0)
2101 		keg->uk_flags |= UMA_ZONE_FIRSTTOUCH;
2102 	else if ((keg->uk_flags & UMA_ZONE_FIRSTTOUCH) == 0)
2103 		keg->uk_flags |= UMA_ZONE_ROUNDROBIN;
2104 #endif
2105 
2106 	/*
2107 	 * If we haven't booted yet we need allocations to go through the
2108 	 * startup cache until the vm is ready.
2109 	 */
2110 #ifdef UMA_MD_SMALL_ALLOC
2111 	if (keg->uk_ppera == 1)
2112 		keg->uk_allocf = uma_small_alloc;
2113 	else
2114 #endif
2115 	if (booted < BOOT_KVA)
2116 		keg->uk_allocf = startup_alloc;
2117 	else if (keg->uk_flags & UMA_ZONE_PCPU)
2118 		keg->uk_allocf = pcpu_page_alloc;
2119 	else if ((keg->uk_flags & UMA_ZONE_CONTIG) != 0 && keg->uk_ppera > 1)
2120 		keg->uk_allocf = contig_alloc;
2121 	else
2122 		keg->uk_allocf = page_alloc;
2123 #ifdef UMA_MD_SMALL_ALLOC
2124 	if (keg->uk_ppera == 1)
2125 		keg->uk_freef = uma_small_free;
2126 	else
2127 #endif
2128 	if (keg->uk_flags & UMA_ZONE_PCPU)
2129 		keg->uk_freef = pcpu_page_free;
2130 	else
2131 		keg->uk_freef = page_free;
2132 
2133 	/*
2134 	 * Initialize keg's locks.
2135 	 */
2136 	for (i = 0; i < vm_ndomains; i++)
2137 		KEG_LOCK_INIT(keg, i, (arg->flags & UMA_ZONE_MTXCLASS));
2138 
2139 	/*
2140 	 * If we're putting the slab header in the actual page we need to
2141 	 * figure out where in each page it goes.  See slab_sizeof
2142 	 * definition.
2143 	 */
2144 	if (!(keg->uk_flags & UMA_ZFLAG_OFFPAGE)) {
2145 		size_t shsize;
2146 
2147 		shsize = slab_sizeof(keg->uk_ipers);
2148 		keg->uk_pgoff = (PAGE_SIZE * keg->uk_ppera) - shsize;
2149 		/*
2150 		 * The only way the following is possible is if with our
2151 		 * UMA_ALIGN_PTR adjustments we are now bigger than
2152 		 * UMA_SLAB_SIZE.  I haven't checked whether this is
2153 		 * mathematically possible for all cases, so we make
2154 		 * sure here anyway.
2155 		 */
2156 		KASSERT(keg->uk_pgoff + shsize <= PAGE_SIZE * keg->uk_ppera,
2157 		    ("zone %s ipers %d rsize %d size %d slab won't fit",
2158 		    zone->uz_name, keg->uk_ipers, keg->uk_rsize, keg->uk_size));
2159 	}
2160 
2161 	if (keg->uk_flags & UMA_ZFLAG_HASH)
2162 		hash_alloc(&keg->uk_hash, 0);
2163 
2164 	CTR3(KTR_UMA, "keg_ctor %p zone %s(%p)", keg, zone->uz_name, zone);
2165 
2166 	LIST_INSERT_HEAD(&keg->uk_zones, zone, uz_link);
2167 
2168 	rw_wlock(&uma_rwlock);
2169 	LIST_INSERT_HEAD(&uma_kegs, keg, uk_link);
2170 	rw_wunlock(&uma_rwlock);
2171 	return (0);
2172 }
2173 
2174 static void
2175 zone_kva_available(uma_zone_t zone, void *unused)
2176 {
2177 	uma_keg_t keg;
2178 
2179 	if ((zone->uz_flags & UMA_ZFLAG_CACHE) != 0)
2180 		return;
2181 	KEG_GET(zone, keg);
2182 
2183 	if (keg->uk_allocf == startup_alloc) {
2184 		/* Switch to the real allocator. */
2185 		if (keg->uk_flags & UMA_ZONE_PCPU)
2186 			keg->uk_allocf = pcpu_page_alloc;
2187 		else if ((keg->uk_flags & UMA_ZONE_CONTIG) != 0 &&
2188 		    keg->uk_ppera > 1)
2189 			keg->uk_allocf = contig_alloc;
2190 		else
2191 			keg->uk_allocf = page_alloc;
2192 	}
2193 }
2194 
2195 static void
2196 zone_alloc_counters(uma_zone_t zone, void *unused)
2197 {
2198 
2199 	zone->uz_allocs = counter_u64_alloc(M_WAITOK);
2200 	zone->uz_frees = counter_u64_alloc(M_WAITOK);
2201 	zone->uz_fails = counter_u64_alloc(M_WAITOK);
2202 }
2203 
2204 static void
2205 zone_alloc_sysctl(uma_zone_t zone, void *unused)
2206 {
2207 	uma_zone_domain_t zdom;
2208 	uma_domain_t dom;
2209 	uma_keg_t keg;
2210 	struct sysctl_oid *oid, *domainoid;
2211 	int domains, i, cnt;
2212 	static const char *nokeg = "cache zone";
2213 	char *c;
2214 
2215 	/*
2216 	 * Make a sysctl safe copy of the zone name by removing
2217 	 * any special characters and handling dups by appending
2218 	 * an index.
2219 	 */
2220 	if (zone->uz_namecnt != 0) {
2221 		/* Count the number of decimal digits and '_' separator. */
2222 		for (i = 1, cnt = zone->uz_namecnt; cnt != 0; i++)
2223 			cnt /= 10;
2224 		zone->uz_ctlname = malloc(strlen(zone->uz_name) + i + 1,
2225 		    M_UMA, M_WAITOK);
2226 		sprintf(zone->uz_ctlname, "%s_%d", zone->uz_name,
2227 		    zone->uz_namecnt);
2228 	} else
2229 		zone->uz_ctlname = strdup(zone->uz_name, M_UMA);
2230 	for (c = zone->uz_ctlname; *c != '\0'; c++)
2231 		if (strchr("./\\ -", *c) != NULL)
2232 			*c = '_';
2233 
2234 	/*
2235 	 * Basic parameters at the root.
2236 	 */
2237 	zone->uz_oid = SYSCTL_ADD_NODE(NULL, SYSCTL_STATIC_CHILDREN(_vm_uma),
2238 	    OID_AUTO, zone->uz_ctlname, CTLFLAG_RD, NULL, "");
2239 	oid = zone->uz_oid;
2240 	SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2241 	    "size", CTLFLAG_RD, &zone->uz_size, 0, "Allocation size");
2242 	SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2243 	    "flags", CTLFLAG_RD | CTLTYPE_STRING | CTLFLAG_MPSAFE,
2244 	    zone, 0, sysctl_handle_uma_zone_flags, "A",
2245 	    "Allocator configuration flags");
2246 	SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2247 	    "bucket_size", CTLFLAG_RD, &zone->uz_bucket_size, 0,
2248 	    "Desired per-cpu cache size");
2249 	SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2250 	    "bucket_size_max", CTLFLAG_RD, &zone->uz_bucket_size_max, 0,
2251 	    "Maximum allowed per-cpu cache size");
2252 
2253 	/*
2254 	 * keg if present.
2255 	 */
2256 	if ((zone->uz_flags & UMA_ZFLAG_HASH) == 0)
2257 		domains = vm_ndomains;
2258 	else
2259 		domains = 1;
2260 	oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid), OID_AUTO,
2261 	    "keg", CTLFLAG_RD, NULL, "");
2262 	keg = zone->uz_keg;
2263 	if ((zone->uz_flags & UMA_ZFLAG_CACHE) == 0) {
2264 		SYSCTL_ADD_CONST_STRING(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2265 		    "name", CTLFLAG_RD, keg->uk_name, "Keg name");
2266 		SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2267 		    "rsize", CTLFLAG_RD, &keg->uk_rsize, 0,
2268 		    "Real object size with alignment");
2269 		SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2270 		    "ppera", CTLFLAG_RD, &keg->uk_ppera, 0,
2271 		    "pages per-slab allocation");
2272 		SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2273 		    "ipers", CTLFLAG_RD, &keg->uk_ipers, 0,
2274 		    "items available per-slab");
2275 		SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2276 		    "align", CTLFLAG_RD, &keg->uk_align, 0,
2277 		    "item alignment mask");
2278 		SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2279 		    "efficiency", CTLFLAG_RD | CTLTYPE_INT | CTLFLAG_MPSAFE,
2280 		    keg, 0, sysctl_handle_uma_slab_efficiency, "I",
2281 		    "Slab utilization (100 - internal fragmentation %)");
2282 		domainoid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(oid),
2283 		    OID_AUTO, "domain", CTLFLAG_RD, NULL, "");
2284 		for (i = 0; i < domains; i++) {
2285 			dom = &keg->uk_domain[i];
2286 			oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(domainoid),
2287 			    OID_AUTO, VM_DOMAIN(i)->vmd_name, CTLFLAG_RD,
2288 			    NULL, "");
2289 			SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2290 			    "pages", CTLFLAG_RD, &dom->ud_pages, 0,
2291 			    "Total pages currently allocated from VM");
2292 			SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2293 			    "free_items", CTLFLAG_RD, &dom->ud_free_items, 0,
2294 			    "items free in the slab layer");
2295 		}
2296 	} else
2297 		SYSCTL_ADD_CONST_STRING(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2298 		    "name", CTLFLAG_RD, nokeg, "Keg name");
2299 
2300 	/*
2301 	 * Information about zone limits.
2302 	 */
2303 	oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid), OID_AUTO,
2304 	    "limit", CTLFLAG_RD, NULL, "");
2305 	SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2306 	    "items", CTLFLAG_RD | CTLTYPE_U64 | CTLFLAG_MPSAFE,
2307 	    zone, 0, sysctl_handle_uma_zone_items, "QU",
2308 	    "current number of allocated items if limit is set");
2309 	SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2310 	    "max_items", CTLFLAG_RD, &zone->uz_max_items, 0,
2311 	    "Maximum number of cached items");
2312 	SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2313 	    "sleepers", CTLFLAG_RD, &zone->uz_sleepers, 0,
2314 	    "Number of threads sleeping at limit");
2315 	SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2316 	    "sleeps", CTLFLAG_RD, &zone->uz_sleeps, 0,
2317 	    "Total zone limit sleeps");
2318 	SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2319 	    "bucket_max", CTLFLAG_RD, &zone->uz_bkt_max, 0,
2320 	    "Maximum number of items in the bucket cache");
2321 	SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2322 	    "bucket_cnt", CTLFLAG_RD, &zone->uz_bkt_count, 0,
2323 	    "Number of items in the bucket cache");
2324 
2325 	/*
2326 	 * Per-domain zone information.
2327 	 */
2328 	domainoid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid),
2329 	    OID_AUTO, "domain", CTLFLAG_RD, NULL, "");
2330 	if ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) == 0)
2331 		domains = 1;
2332 	for (i = 0; i < domains; i++) {
2333 		zdom = &zone->uz_domain[i];
2334 		oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(domainoid),
2335 		    OID_AUTO, VM_DOMAIN(i)->vmd_name, CTLFLAG_RD, NULL, "");
2336 		SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2337 		    "nitems", CTLFLAG_RD, &zdom->uzd_nitems,
2338 		    "number of items in this domain");
2339 		SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2340 		    "imax", CTLFLAG_RD, &zdom->uzd_imax,
2341 		    "maximum item count in this period");
2342 		SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2343 		    "imin", CTLFLAG_RD, &zdom->uzd_imin,
2344 		    "minimum item count in this period");
2345 		SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2346 		    "wss", CTLFLAG_RD, &zdom->uzd_wss,
2347 		    "Working set size");
2348 	}
2349 
2350 	/*
2351 	 * General statistics.
2352 	 */
2353 	oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid), OID_AUTO,
2354 	    "stats", CTLFLAG_RD, NULL, "");
2355 	SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2356 	    "current", CTLFLAG_RD | CTLTYPE_INT | CTLFLAG_MPSAFE,
2357 	    zone, 1, sysctl_handle_uma_zone_cur, "I",
2358 	    "Current number of allocated items");
2359 	SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2360 	    "allocs", CTLFLAG_RD | CTLTYPE_U64 | CTLFLAG_MPSAFE,
2361 	    zone, 0, sysctl_handle_uma_zone_allocs, "QU",
2362 	    "Total allocation calls");
2363 	SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2364 	    "frees", CTLFLAG_RD | CTLTYPE_U64 | CTLFLAG_MPSAFE,
2365 	    zone, 0, sysctl_handle_uma_zone_frees, "QU",
2366 	    "Total free calls");
2367 	SYSCTL_ADD_COUNTER_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2368 	    "fails", CTLFLAG_RD, &zone->uz_fails,
2369 	    "Number of allocation failures");
2370 	SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2371 	    "xdomain", CTLFLAG_RD, &zone->uz_xdomain, 0,
2372 	    "Free calls from the wrong domain");
2373 }
2374 
2375 struct uma_zone_count {
2376 	const char	*name;
2377 	int		count;
2378 };
2379 
2380 static void
2381 zone_count(uma_zone_t zone, void *arg)
2382 {
2383 	struct uma_zone_count *cnt;
2384 
2385 	cnt = arg;
2386 	/*
2387 	 * Some zones are rapidly created with identical names and
2388 	 * destroyed out of order.  This can lead to gaps in the count.
2389 	 * Use one greater than the maximum observed for this name.
2390 	 */
2391 	if (strcmp(zone->uz_name, cnt->name) == 0)
2392 		cnt->count = MAX(cnt->count,
2393 		    zone->uz_namecnt + 1);
2394 }
2395 
2396 static void
2397 zone_update_caches(uma_zone_t zone)
2398 {
2399 	int i;
2400 
2401 	for (i = 0; i <= mp_maxid; i++) {
2402 		cache_set_uz_size(&zone->uz_cpu[i], zone->uz_size);
2403 		cache_set_uz_flags(&zone->uz_cpu[i], zone->uz_flags);
2404 	}
2405 }
2406 
2407 /*
2408  * Zone header ctor.  This initializes all fields, locks, etc.
2409  *
2410  * Arguments/Returns follow uma_ctor specifications
2411  *	udata  Actually uma_zctor_args
2412  */
2413 static int
2414 zone_ctor(void *mem, int size, void *udata, int flags)
2415 {
2416 	struct uma_zone_count cnt;
2417 	struct uma_zctor_args *arg = udata;
2418 	uma_zone_t zone = mem;
2419 	uma_zone_t z;
2420 	uma_keg_t keg;
2421 	int i;
2422 
2423 	bzero(zone, size);
2424 	zone->uz_name = arg->name;
2425 	zone->uz_ctor = arg->ctor;
2426 	zone->uz_dtor = arg->dtor;
2427 	zone->uz_init = NULL;
2428 	zone->uz_fini = NULL;
2429 	zone->uz_sleeps = 0;
2430 	zone->uz_xdomain = 0;
2431 	zone->uz_bucket_size = 0;
2432 	zone->uz_bucket_size_min = 0;
2433 	zone->uz_bucket_size_max = BUCKET_MAX;
2434 	zone->uz_flags = (arg->flags & UMA_ZONE_SMR);
2435 	zone->uz_warning = NULL;
2436 	/* The domain structures follow the cpu structures. */
2437 	zone->uz_domain =
2438 	    (struct uma_zone_domain *)&zone->uz_cpu[mp_maxid + 1];
2439 	zone->uz_bkt_max = ULONG_MAX;
2440 	timevalclear(&zone->uz_ratecheck);
2441 
2442 	/* Count the number of duplicate names. */
2443 	cnt.name = arg->name;
2444 	cnt.count = 0;
2445 	zone_foreach(zone_count, &cnt);
2446 	zone->uz_namecnt = cnt.count;
2447 	ZONE_LOCK_INIT(zone, (arg->flags & UMA_ZONE_MTXCLASS));
2448 	ZONE_CROSS_LOCK_INIT(zone);
2449 
2450 	for (i = 0; i < vm_ndomains; i++)
2451 		STAILQ_INIT(&zone->uz_domain[i].uzd_buckets);
2452 
2453 #ifdef INVARIANTS
2454 	if (arg->uminit == trash_init && arg->fini == trash_fini)
2455 		zone->uz_flags |= UMA_ZFLAG_TRASH | UMA_ZFLAG_CTORDTOR;
2456 #endif
2457 
2458 	/*
2459 	 * This is a pure cache zone, no kegs.
2460 	 */
2461 	if (arg->import) {
2462 		KASSERT((arg->flags & UMA_ZFLAG_CACHE) != 0,
2463 		    ("zone_ctor: Import specified for non-cache zone."));
2464 		zone->uz_flags = arg->flags;
2465 		zone->uz_size = arg->size;
2466 		zone->uz_import = arg->import;
2467 		zone->uz_release = arg->release;
2468 		zone->uz_arg = arg->arg;
2469 		rw_wlock(&uma_rwlock);
2470 		LIST_INSERT_HEAD(&uma_cachezones, zone, uz_link);
2471 		rw_wunlock(&uma_rwlock);
2472 		goto out;
2473 	}
2474 
2475 	/*
2476 	 * Use the regular zone/keg/slab allocator.
2477 	 */
2478 	zone->uz_import = zone_import;
2479 	zone->uz_release = zone_release;
2480 	zone->uz_arg = zone;
2481 	keg = arg->keg;
2482 
2483 	if (arg->flags & UMA_ZONE_SECONDARY) {
2484 		KASSERT((zone->uz_flags & UMA_ZONE_SECONDARY) == 0,
2485 		    ("Secondary zone requested UMA_ZFLAG_INTERNAL"));
2486 		KASSERT(arg->keg != NULL, ("Secondary zone on zero'd keg"));
2487 		zone->uz_init = arg->uminit;
2488 		zone->uz_fini = arg->fini;
2489 		zone->uz_flags |= UMA_ZONE_SECONDARY;
2490 		rw_wlock(&uma_rwlock);
2491 		ZONE_LOCK(zone);
2492 		LIST_FOREACH(z, &keg->uk_zones, uz_link) {
2493 			if (LIST_NEXT(z, uz_link) == NULL) {
2494 				LIST_INSERT_AFTER(z, zone, uz_link);
2495 				break;
2496 			}
2497 		}
2498 		ZONE_UNLOCK(zone);
2499 		rw_wunlock(&uma_rwlock);
2500 	} else if (keg == NULL) {
2501 		if ((keg = uma_kcreate(zone, arg->size, arg->uminit, arg->fini,
2502 		    arg->align, arg->flags)) == NULL)
2503 			return (ENOMEM);
2504 	} else {
2505 		struct uma_kctor_args karg;
2506 		int error;
2507 
2508 		/* We should only be here from uma_startup() */
2509 		karg.size = arg->size;
2510 		karg.uminit = arg->uminit;
2511 		karg.fini = arg->fini;
2512 		karg.align = arg->align;
2513 		karg.flags = (arg->flags & ~UMA_ZONE_SMR);
2514 		karg.zone = zone;
2515 		error = keg_ctor(arg->keg, sizeof(struct uma_keg), &karg,
2516 		    flags);
2517 		if (error)
2518 			return (error);
2519 	}
2520 
2521 	/* Inherit properties from the keg. */
2522 	zone->uz_keg = keg;
2523 	zone->uz_size = keg->uk_size;
2524 	zone->uz_flags |= (keg->uk_flags &
2525 	    (UMA_ZONE_INHERIT | UMA_ZFLAG_INHERIT));
2526 
2527 out:
2528 	if (__predict_true(booted >= BOOT_RUNNING)) {
2529 		zone_alloc_counters(zone, NULL);
2530 		zone_alloc_sysctl(zone, NULL);
2531 	} else {
2532 		zone->uz_allocs = EARLY_COUNTER;
2533 		zone->uz_frees = EARLY_COUNTER;
2534 		zone->uz_fails = EARLY_COUNTER;
2535 	}
2536 
2537 	/* Caller requests a private SMR context. */
2538 	if ((zone->uz_flags & UMA_ZONE_SMR) != 0)
2539 		zone->uz_smr = smr_create(zone->uz_name);
2540 
2541 	KASSERT((arg->flags & (UMA_ZONE_MAXBUCKET | UMA_ZONE_NOBUCKET)) !=
2542 	    (UMA_ZONE_MAXBUCKET | UMA_ZONE_NOBUCKET),
2543 	    ("Invalid zone flag combination"));
2544 	if (arg->flags & UMA_ZFLAG_INTERNAL)
2545 		zone->uz_bucket_size_max = zone->uz_bucket_size = 0;
2546 	if ((arg->flags & UMA_ZONE_MAXBUCKET) != 0)
2547 		zone->uz_bucket_size = BUCKET_MAX;
2548 	else if ((arg->flags & UMA_ZONE_MINBUCKET) != 0)
2549 		zone->uz_bucket_size_max = zone->uz_bucket_size = BUCKET_MIN;
2550 	else if ((arg->flags & UMA_ZONE_NOBUCKET) != 0)
2551 		zone->uz_bucket_size = 0;
2552 	else
2553 		zone->uz_bucket_size = bucket_select(zone->uz_size);
2554 	zone->uz_bucket_size_min = zone->uz_bucket_size;
2555 	if (zone->uz_dtor != NULL || zone->uz_ctor != NULL)
2556 		zone->uz_flags |= UMA_ZFLAG_CTORDTOR;
2557 	zone_update_caches(zone);
2558 
2559 	return (0);
2560 }
2561 
2562 /*
2563  * Keg header dtor.  This frees all data, destroys locks, frees the hash
2564  * table and removes the keg from the global list.
2565  *
2566  * Arguments/Returns follow uma_dtor specifications
2567  *	udata  unused
2568  */
2569 static void
2570 keg_dtor(void *arg, int size, void *udata)
2571 {
2572 	uma_keg_t keg;
2573 	uint32_t free, pages;
2574 	int i;
2575 
2576 	keg = (uma_keg_t)arg;
2577 	free = pages = 0;
2578 	for (i = 0; i < vm_ndomains; i++) {
2579 		free += keg->uk_domain[i].ud_free_items;
2580 		pages += keg->uk_domain[i].ud_pages;
2581 		KEG_LOCK_FINI(keg, i);
2582 	}
2583 	if (pages != 0)
2584 		printf("Freed UMA keg (%s) was not empty (%u items). "
2585 		    " Lost %u pages of memory.\n",
2586 		    keg->uk_name ? keg->uk_name : "",
2587 		    pages / keg->uk_ppera * keg->uk_ipers - free, pages);
2588 
2589 	hash_free(&keg->uk_hash);
2590 }
2591 
2592 /*
2593  * Zone header dtor.
2594  *
2595  * Arguments/Returns follow uma_dtor specifications
2596  *	udata  unused
2597  */
2598 static void
2599 zone_dtor(void *arg, int size, void *udata)
2600 {
2601 	uma_zone_t zone;
2602 	uma_keg_t keg;
2603 
2604 	zone = (uma_zone_t)arg;
2605 
2606 	sysctl_remove_oid(zone->uz_oid, 1, 1);
2607 
2608 	if (!(zone->uz_flags & UMA_ZFLAG_INTERNAL))
2609 		cache_drain(zone);
2610 
2611 	rw_wlock(&uma_rwlock);
2612 	LIST_REMOVE(zone, uz_link);
2613 	rw_wunlock(&uma_rwlock);
2614 	/*
2615 	 * XXX there are some races here where
2616 	 * the zone can be drained but zone lock
2617 	 * released and then refilled before we
2618 	 * remove it... we dont care for now
2619 	 */
2620 	zone_reclaim(zone, M_WAITOK, true);
2621 	/*
2622 	 * We only destroy kegs from non secondary/non cache zones.
2623 	 */
2624 	if ((zone->uz_flags & (UMA_ZONE_SECONDARY | UMA_ZFLAG_CACHE)) == 0) {
2625 		keg = zone->uz_keg;
2626 		rw_wlock(&uma_rwlock);
2627 		LIST_REMOVE(keg, uk_link);
2628 		rw_wunlock(&uma_rwlock);
2629 		zone_free_item(kegs, keg, NULL, SKIP_NONE);
2630 	}
2631 	counter_u64_free(zone->uz_allocs);
2632 	counter_u64_free(zone->uz_frees);
2633 	counter_u64_free(zone->uz_fails);
2634 	free(zone->uz_ctlname, M_UMA);
2635 	ZONE_LOCK_FINI(zone);
2636 	ZONE_CROSS_LOCK_FINI(zone);
2637 }
2638 
2639 static void
2640 zone_foreach_unlocked(void (*zfunc)(uma_zone_t, void *arg), void *arg)
2641 {
2642 	uma_keg_t keg;
2643 	uma_zone_t zone;
2644 
2645 	LIST_FOREACH(keg, &uma_kegs, uk_link) {
2646 		LIST_FOREACH(zone, &keg->uk_zones, uz_link)
2647 			zfunc(zone, arg);
2648 	}
2649 	LIST_FOREACH(zone, &uma_cachezones, uz_link)
2650 		zfunc(zone, arg);
2651 }
2652 
2653 /*
2654  * Traverses every zone in the system and calls a callback
2655  *
2656  * Arguments:
2657  *	zfunc  A pointer to a function which accepts a zone
2658  *		as an argument.
2659  *
2660  * Returns:
2661  *	Nothing
2662  */
2663 static void
2664 zone_foreach(void (*zfunc)(uma_zone_t, void *arg), void *arg)
2665 {
2666 
2667 	rw_rlock(&uma_rwlock);
2668 	zone_foreach_unlocked(zfunc, arg);
2669 	rw_runlock(&uma_rwlock);
2670 }
2671 
2672 /*
2673  * Initialize the kernel memory allocator.  This is done after pages can be
2674  * allocated but before general KVA is available.
2675  */
2676 void
2677 uma_startup1(vm_offset_t virtual_avail)
2678 {
2679 	struct uma_zctor_args args;
2680 	size_t ksize, zsize, size;
2681 	uma_keg_t masterkeg;
2682 	uintptr_t m;
2683 	uint8_t pflag;
2684 
2685 	bootstart = bootmem = virtual_avail;
2686 
2687 	rw_init(&uma_rwlock, "UMA lock");
2688 	sx_init(&uma_reclaim_lock, "umareclaim");
2689 
2690 	ksize = sizeof(struct uma_keg) +
2691 	    (sizeof(struct uma_domain) * vm_ndomains);
2692 	ksize = roundup(ksize, UMA_SUPER_ALIGN);
2693 	zsize = sizeof(struct uma_zone) +
2694 	    (sizeof(struct uma_cache) * (mp_maxid + 1)) +
2695 	    (sizeof(struct uma_zone_domain) * vm_ndomains);
2696 	zsize = roundup(zsize, UMA_SUPER_ALIGN);
2697 
2698 	/* Allocate the zone of zones, zone of kegs, and zone of zones keg. */
2699 	size = (zsize * 2) + ksize;
2700 	m = (uintptr_t)startup_alloc(NULL, size, 0, &pflag, M_NOWAIT | M_ZERO);
2701 	zones = (uma_zone_t)m;
2702 	m += zsize;
2703 	kegs = (uma_zone_t)m;
2704 	m += zsize;
2705 	masterkeg = (uma_keg_t)m;
2706 
2707 	/* "manually" create the initial zone */
2708 	memset(&args, 0, sizeof(args));
2709 	args.name = "UMA Kegs";
2710 	args.size = ksize;
2711 	args.ctor = keg_ctor;
2712 	args.dtor = keg_dtor;
2713 	args.uminit = zero_init;
2714 	args.fini = NULL;
2715 	args.keg = masterkeg;
2716 	args.align = UMA_SUPER_ALIGN - 1;
2717 	args.flags = UMA_ZFLAG_INTERNAL;
2718 	zone_ctor(kegs, zsize, &args, M_WAITOK);
2719 
2720 	args.name = "UMA Zones";
2721 	args.size = zsize;
2722 	args.ctor = zone_ctor;
2723 	args.dtor = zone_dtor;
2724 	args.uminit = zero_init;
2725 	args.fini = NULL;
2726 	args.keg = NULL;
2727 	args.align = UMA_SUPER_ALIGN - 1;
2728 	args.flags = UMA_ZFLAG_INTERNAL;
2729 	zone_ctor(zones, zsize, &args, M_WAITOK);
2730 
2731 	/* Now make zones for slab headers */
2732 	slabzones[0] = uma_zcreate("UMA Slabs 0", SLABZONE0_SIZE,
2733 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
2734 	slabzones[1] = uma_zcreate("UMA Slabs 1", SLABZONE1_SIZE,
2735 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
2736 
2737 	hashzone = uma_zcreate("UMA Hash",
2738 	    sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT,
2739 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
2740 
2741 	bucket_init();
2742 	smr_init();
2743 }
2744 
2745 #ifndef UMA_MD_SMALL_ALLOC
2746 extern void vm_radix_reserve_kva(void);
2747 #endif
2748 
2749 /*
2750  * Advertise the availability of normal kva allocations and switch to
2751  * the default back-end allocator.  Marks the KVA we consumed on startup
2752  * as used in the map.
2753  */
2754 void
2755 uma_startup2(void)
2756 {
2757 
2758 	if (bootstart != bootmem) {
2759 		vm_map_lock(kernel_map);
2760 		(void)vm_map_insert(kernel_map, NULL, 0, bootstart, bootmem,
2761 		    VM_PROT_RW, VM_PROT_RW, MAP_NOFAULT);
2762 		vm_map_unlock(kernel_map);
2763 	}
2764 
2765 #ifndef UMA_MD_SMALL_ALLOC
2766 	/* Set up radix zone to use noobj_alloc. */
2767 	vm_radix_reserve_kva();
2768 #endif
2769 
2770 	booted = BOOT_KVA;
2771 	zone_foreach_unlocked(zone_kva_available, NULL);
2772 	bucket_enable();
2773 }
2774 
2775 /*
2776  * Finish our initialization steps.
2777  */
2778 static void
2779 uma_startup3(void)
2780 {
2781 
2782 #ifdef INVARIANTS
2783 	TUNABLE_INT_FETCH("vm.debug.divisor", &dbg_divisor);
2784 	uma_dbg_cnt = counter_u64_alloc(M_WAITOK);
2785 	uma_skip_cnt = counter_u64_alloc(M_WAITOK);
2786 #endif
2787 	zone_foreach_unlocked(zone_alloc_counters, NULL);
2788 	zone_foreach_unlocked(zone_alloc_sysctl, NULL);
2789 	callout_init(&uma_callout, 1);
2790 	callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
2791 	booted = BOOT_RUNNING;
2792 
2793 	EVENTHANDLER_REGISTER(shutdown_post_sync, uma_shutdown, NULL,
2794 	    EVENTHANDLER_PRI_FIRST);
2795 }
2796 
2797 static void
2798 uma_shutdown(void)
2799 {
2800 
2801 	booted = BOOT_SHUTDOWN;
2802 }
2803 
2804 static uma_keg_t
2805 uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini,
2806 		int align, uint32_t flags)
2807 {
2808 	struct uma_kctor_args args;
2809 
2810 	args.size = size;
2811 	args.uminit = uminit;
2812 	args.fini = fini;
2813 	args.align = (align == UMA_ALIGN_CACHE) ? uma_align_cache : align;
2814 	args.flags = flags;
2815 	args.zone = zone;
2816 	return (zone_alloc_item(kegs, &args, UMA_ANYDOMAIN, M_WAITOK));
2817 }
2818 
2819 /* Public functions */
2820 /* See uma.h */
2821 void
2822 uma_set_align(int align)
2823 {
2824 
2825 	if (align != UMA_ALIGN_CACHE)
2826 		uma_align_cache = align;
2827 }
2828 
2829 /* See uma.h */
2830 uma_zone_t
2831 uma_zcreate(const char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
2832 		uma_init uminit, uma_fini fini, int align, uint32_t flags)
2833 
2834 {
2835 	struct uma_zctor_args args;
2836 	uma_zone_t res;
2837 
2838 	KASSERT(powerof2(align + 1), ("invalid zone alignment %d for \"%s\"",
2839 	    align, name));
2840 
2841 	/* This stuff is essential for the zone ctor */
2842 	memset(&args, 0, sizeof(args));
2843 	args.name = name;
2844 	args.size = size;
2845 	args.ctor = ctor;
2846 	args.dtor = dtor;
2847 	args.uminit = uminit;
2848 	args.fini = fini;
2849 #ifdef  INVARIANTS
2850 	/*
2851 	 * Inject procedures which check for memory use after free if we are
2852 	 * allowed to scramble the memory while it is not allocated.  This
2853 	 * requires that: UMA is actually able to access the memory, no init
2854 	 * or fini procedures, no dependency on the initial value of the
2855 	 * memory, and no (legitimate) use of the memory after free.  Note,
2856 	 * the ctor and dtor do not need to be empty.
2857 	 */
2858 	if ((!(flags & (UMA_ZONE_ZINIT | UMA_ZONE_NOTOUCH |
2859 	    UMA_ZONE_NOFREE))) && uminit == NULL && fini == NULL) {
2860 		args.uminit = trash_init;
2861 		args.fini = trash_fini;
2862 	}
2863 #endif
2864 	args.align = align;
2865 	args.flags = flags;
2866 	args.keg = NULL;
2867 
2868 	sx_slock(&uma_reclaim_lock);
2869 	res = zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK);
2870 	sx_sunlock(&uma_reclaim_lock);
2871 
2872 	return (res);
2873 }
2874 
2875 /* See uma.h */
2876 uma_zone_t
2877 uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
2878 		    uma_init zinit, uma_fini zfini, uma_zone_t master)
2879 {
2880 	struct uma_zctor_args args;
2881 	uma_keg_t keg;
2882 	uma_zone_t res;
2883 
2884 	keg = master->uz_keg;
2885 	memset(&args, 0, sizeof(args));
2886 	args.name = name;
2887 	args.size = keg->uk_size;
2888 	args.ctor = ctor;
2889 	args.dtor = dtor;
2890 	args.uminit = zinit;
2891 	args.fini = zfini;
2892 	args.align = keg->uk_align;
2893 	args.flags = keg->uk_flags | UMA_ZONE_SECONDARY;
2894 	args.keg = keg;
2895 
2896 	sx_slock(&uma_reclaim_lock);
2897 	res = zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK);
2898 	sx_sunlock(&uma_reclaim_lock);
2899 
2900 	return (res);
2901 }
2902 
2903 /* See uma.h */
2904 uma_zone_t
2905 uma_zcache_create(char *name, int size, uma_ctor ctor, uma_dtor dtor,
2906 		    uma_init zinit, uma_fini zfini, uma_import zimport,
2907 		    uma_release zrelease, void *arg, int flags)
2908 {
2909 	struct uma_zctor_args args;
2910 
2911 	memset(&args, 0, sizeof(args));
2912 	args.name = name;
2913 	args.size = size;
2914 	args.ctor = ctor;
2915 	args.dtor = dtor;
2916 	args.uminit = zinit;
2917 	args.fini = zfini;
2918 	args.import = zimport;
2919 	args.release = zrelease;
2920 	args.arg = arg;
2921 	args.align = 0;
2922 	args.flags = flags | UMA_ZFLAG_CACHE;
2923 
2924 	return (zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK));
2925 }
2926 
2927 /* See uma.h */
2928 void
2929 uma_zdestroy(uma_zone_t zone)
2930 {
2931 
2932 	/*
2933 	 * Large slabs are expensive to reclaim, so don't bother doing
2934 	 * unnecessary work if we're shutting down.
2935 	 */
2936 	if (booted == BOOT_SHUTDOWN &&
2937 	    zone->uz_fini == NULL && zone->uz_release == zone_release)
2938 		return;
2939 	sx_slock(&uma_reclaim_lock);
2940 	zone_free_item(zones, zone, NULL, SKIP_NONE);
2941 	sx_sunlock(&uma_reclaim_lock);
2942 }
2943 
2944 void
2945 uma_zwait(uma_zone_t zone)
2946 {
2947 	void *item;
2948 
2949 	item = uma_zalloc_arg(zone, NULL, M_WAITOK);
2950 	uma_zfree(zone, item);
2951 }
2952 
2953 void *
2954 uma_zalloc_pcpu_arg(uma_zone_t zone, void *udata, int flags)
2955 {
2956 	void *item, *pcpu_item;
2957 #ifdef SMP
2958 	int i;
2959 
2960 	MPASS(zone->uz_flags & UMA_ZONE_PCPU);
2961 #endif
2962 	item = uma_zalloc_arg(zone, udata, flags & ~M_ZERO);
2963 	if (item == NULL)
2964 		return (NULL);
2965 	pcpu_item = zpcpu_base_to_offset(item);
2966 	if (flags & M_ZERO) {
2967 #ifdef SMP
2968 		for (i = 0; i <= mp_maxid; i++)
2969 			bzero(zpcpu_get_cpu(pcpu_item, i), zone->uz_size);
2970 #else
2971 		bzero(item, zone->uz_size);
2972 #endif
2973 	}
2974 	return (pcpu_item);
2975 }
2976 
2977 /*
2978  * A stub while both regular and pcpu cases are identical.
2979  */
2980 void
2981 uma_zfree_pcpu_arg(uma_zone_t zone, void *pcpu_item, void *udata)
2982 {
2983 	void *item;
2984 
2985 #ifdef SMP
2986 	MPASS(zone->uz_flags & UMA_ZONE_PCPU);
2987 #endif
2988 	item = zpcpu_offset_to_base(pcpu_item);
2989 	uma_zfree_arg(zone, item, udata);
2990 }
2991 
2992 static inline void *
2993 item_ctor(uma_zone_t zone, int uz_flags, int size, void *udata, int flags,
2994     void *item)
2995 {
2996 #ifdef INVARIANTS
2997 	bool skipdbg;
2998 
2999 	skipdbg = uma_dbg_zskip(zone, item);
3000 	if (!skipdbg && (zone->uz_flags & UMA_ZFLAG_TRASH) != 0 &&
3001 	    zone->uz_ctor != trash_ctor)
3002 		trash_ctor(item, size, udata, flags);
3003 #endif
3004 	/* Check flags before loading ctor pointer. */
3005 	if (__predict_false((uz_flags & UMA_ZFLAG_CTORDTOR) != 0) &&
3006 	    __predict_false(zone->uz_ctor != NULL) &&
3007 	    zone->uz_ctor(item, size, udata, flags) != 0) {
3008 		counter_u64_add(zone->uz_fails, 1);
3009 		zone_free_item(zone, item, udata, SKIP_DTOR | SKIP_CNT);
3010 		return (NULL);
3011 	}
3012 #ifdef INVARIANTS
3013 	if (!skipdbg)
3014 		uma_dbg_alloc(zone, NULL, item);
3015 #endif
3016 	if (flags & M_ZERO)
3017 		bzero(item, size);
3018 
3019 	return (item);
3020 }
3021 
3022 static inline void
3023 item_dtor(uma_zone_t zone, void *item, int size, void *udata,
3024     enum zfreeskip skip)
3025 {
3026 #ifdef INVARIANTS
3027 	bool skipdbg;
3028 
3029 	skipdbg = uma_dbg_zskip(zone, item);
3030 	if (skip == SKIP_NONE && !skipdbg) {
3031 		if ((zone->uz_flags & UMA_ZONE_MALLOC) != 0)
3032 			uma_dbg_free(zone, udata, item);
3033 		else
3034 			uma_dbg_free(zone, NULL, item);
3035 	}
3036 #endif
3037 	if (__predict_true(skip < SKIP_DTOR)) {
3038 		if (zone->uz_dtor != NULL)
3039 			zone->uz_dtor(item, size, udata);
3040 #ifdef INVARIANTS
3041 		if (!skipdbg && (zone->uz_flags & UMA_ZFLAG_TRASH) != 0 &&
3042 		    zone->uz_dtor != trash_dtor)
3043 			trash_dtor(item, size, udata);
3044 #endif
3045 	}
3046 }
3047 
3048 #if defined(INVARIANTS) || defined(DEBUG_MEMGUARD) || defined(WITNESS)
3049 #define	UMA_ZALLOC_DEBUG
3050 static int
3051 uma_zalloc_debug(uma_zone_t zone, void **itemp, void *udata, int flags)
3052 {
3053 	int error;
3054 
3055 	error = 0;
3056 #ifdef WITNESS
3057 	if (flags & M_WAITOK) {
3058 		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
3059 		    "uma_zalloc_debug: zone \"%s\"", zone->uz_name);
3060 	}
3061 #endif
3062 
3063 #ifdef INVARIANTS
3064 	KASSERT((flags & M_EXEC) == 0,
3065 	    ("uma_zalloc_debug: called with M_EXEC"));
3066 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
3067 	    ("uma_zalloc_debug: called within spinlock or critical section"));
3068 	KASSERT((zone->uz_flags & UMA_ZONE_PCPU) == 0 || (flags & M_ZERO) == 0,
3069 	    ("uma_zalloc_debug: allocating from a pcpu zone with M_ZERO"));
3070 #endif
3071 
3072 #ifdef DEBUG_MEMGUARD
3073 	if ((zone->uz_flags & UMA_ZONE_SMR) == 0 && memguard_cmp_zone(zone)) {
3074 		void *item;
3075 		item = memguard_alloc(zone->uz_size, flags);
3076 		if (item != NULL) {
3077 			error = EJUSTRETURN;
3078 			if (zone->uz_init != NULL &&
3079 			    zone->uz_init(item, zone->uz_size, flags) != 0) {
3080 				*itemp = NULL;
3081 				return (error);
3082 			}
3083 			if (zone->uz_ctor != NULL &&
3084 			    zone->uz_ctor(item, zone->uz_size, udata,
3085 			    flags) != 0) {
3086 				counter_u64_add(zone->uz_fails, 1);
3087 			    	zone->uz_fini(item, zone->uz_size);
3088 				*itemp = NULL;
3089 				return (error);
3090 			}
3091 			*itemp = item;
3092 			return (error);
3093 		}
3094 		/* This is unfortunate but should not be fatal. */
3095 	}
3096 #endif
3097 	return (error);
3098 }
3099 
3100 static int
3101 uma_zfree_debug(uma_zone_t zone, void *item, void *udata)
3102 {
3103 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
3104 	    ("uma_zfree_debug: called with spinlock or critical section held"));
3105 
3106 #ifdef DEBUG_MEMGUARD
3107 	if ((zone->uz_flags & UMA_ZONE_SMR) == 0 && is_memguard_addr(item)) {
3108 		if (zone->uz_dtor != NULL)
3109 			zone->uz_dtor(item, zone->uz_size, udata);
3110 		if (zone->uz_fini != NULL)
3111 			zone->uz_fini(item, zone->uz_size);
3112 		memguard_free(item);
3113 		return (EJUSTRETURN);
3114 	}
3115 #endif
3116 	return (0);
3117 }
3118 #endif
3119 
3120 static __noinline void *
3121 uma_zalloc_single(uma_zone_t zone, void *udata, int flags)
3122 {
3123 	int domain;
3124 
3125 	/*
3126 	 * We can not get a bucket so try to return a single item.
3127 	 */
3128 	if (zone->uz_flags & UMA_ZONE_FIRSTTOUCH)
3129 		domain = PCPU_GET(domain);
3130 	else
3131 		domain = UMA_ANYDOMAIN;
3132 	return (zone_alloc_item(zone, udata, domain, flags));
3133 }
3134 
3135 /* See uma.h */
3136 void *
3137 uma_zalloc_smr(uma_zone_t zone, int flags)
3138 {
3139 	uma_cache_bucket_t bucket;
3140 	uma_cache_t cache;
3141 	void *item;
3142 	int size, uz_flags;
3143 
3144 #ifdef UMA_ZALLOC_DEBUG
3145 	KASSERT((zone->uz_flags & UMA_ZONE_SMR) != 0,
3146 	    ("uma_zalloc_arg: called with non-SMR zone.\n"));
3147 	if (uma_zalloc_debug(zone, &item, NULL, flags) == EJUSTRETURN)
3148 		return (item);
3149 #endif
3150 
3151 	critical_enter();
3152 	do {
3153 		cache = &zone->uz_cpu[curcpu];
3154 		bucket = &cache->uc_allocbucket;
3155 		size = cache_uz_size(cache);
3156 		uz_flags = cache_uz_flags(cache);
3157 		if (__predict_true(bucket->ucb_cnt != 0)) {
3158 			item = cache_bucket_pop(cache, bucket);
3159 			critical_exit();
3160 			return (item_ctor(zone, uz_flags, size, NULL, flags,
3161 			    item));
3162 		}
3163 	} while (cache_alloc(zone, cache, NULL, flags));
3164 	critical_exit();
3165 
3166 	return (uma_zalloc_single(zone, NULL, flags));
3167 }
3168 
3169 /* See uma.h */
3170 void *
3171 uma_zalloc_arg(uma_zone_t zone, void *udata, int flags)
3172 {
3173 	uma_cache_bucket_t bucket;
3174 	uma_cache_t cache;
3175 	void *item;
3176 	int size, uz_flags;
3177 
3178 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
3179 	random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
3180 
3181 	/* This is the fast path allocation */
3182 	CTR3(KTR_UMA, "uma_zalloc_arg zone %s(%p) flags %d", zone->uz_name,
3183 	    zone, flags);
3184 
3185 #ifdef UMA_ZALLOC_DEBUG
3186 	KASSERT((zone->uz_flags & UMA_ZONE_SMR) == 0,
3187 	    ("uma_zalloc_arg: called with SMR zone.\n"));
3188 	if (uma_zalloc_debug(zone, &item, udata, flags) == EJUSTRETURN)
3189 		return (item);
3190 #endif
3191 
3192 	/*
3193 	 * If possible, allocate from the per-CPU cache.  There are two
3194 	 * requirements for safe access to the per-CPU cache: (1) the thread
3195 	 * accessing the cache must not be preempted or yield during access,
3196 	 * and (2) the thread must not migrate CPUs without switching which
3197 	 * cache it accesses.  We rely on a critical section to prevent
3198 	 * preemption and migration.  We release the critical section in
3199 	 * order to acquire the zone mutex if we are unable to allocate from
3200 	 * the current cache; when we re-acquire the critical section, we
3201 	 * must detect and handle migration if it has occurred.
3202 	 */
3203 	critical_enter();
3204 	do {
3205 		cache = &zone->uz_cpu[curcpu];
3206 		bucket = &cache->uc_allocbucket;
3207 		size = cache_uz_size(cache);
3208 		uz_flags = cache_uz_flags(cache);
3209 		if (__predict_true(bucket->ucb_cnt != 0)) {
3210 			item = cache_bucket_pop(cache, bucket);
3211 			critical_exit();
3212 			return (item_ctor(zone, uz_flags, size, udata, flags,
3213 			    item));
3214 		}
3215 	} while (cache_alloc(zone, cache, udata, flags));
3216 	critical_exit();
3217 
3218 	return (uma_zalloc_single(zone, udata, flags));
3219 }
3220 
3221 /*
3222  * Replenish an alloc bucket and possibly restore an old one.  Called in
3223  * a critical section.  Returns in a critical section.
3224  *
3225  * A false return value indicates an allocation failure.
3226  * A true return value indicates success and the caller should retry.
3227  */
3228 static __noinline bool
3229 cache_alloc(uma_zone_t zone, uma_cache_t cache, void *udata, int flags)
3230 {
3231 	uma_zone_domain_t zdom;
3232 	uma_bucket_t bucket;
3233 	int domain;
3234 	bool lockfail;
3235 
3236 	CRITICAL_ASSERT(curthread);
3237 
3238 	/*
3239 	 * If we have run out of items in our alloc bucket see
3240 	 * if we can switch with the free bucket.
3241 	 *
3242 	 * SMR Zones can't re-use the free bucket until the sequence has
3243 	 * expired.
3244 	 */
3245 	if ((zone->uz_flags & UMA_ZONE_SMR) == 0 &&
3246 	    cache->uc_freebucket.ucb_cnt != 0) {
3247 		cache_bucket_swap(&cache->uc_freebucket,
3248 		    &cache->uc_allocbucket);
3249 		return (true);
3250 	}
3251 
3252 	/*
3253 	 * Discard any empty allocation bucket while we hold no locks.
3254 	 */
3255 	bucket = cache_bucket_unload_alloc(cache);
3256 	critical_exit();
3257 	if (bucket != NULL)
3258 		bucket_free(zone, bucket, udata);
3259 
3260 	/* Short-circuit for zones without buckets and low memory. */
3261 	if (zone->uz_bucket_size == 0 || bucketdisable) {
3262 		critical_enter();
3263 		return (false);
3264 	}
3265 
3266 	/*
3267 	 * Attempt to retrieve the item from the per-CPU cache has failed, so
3268 	 * we must go back to the zone.  This requires the zone lock, so we
3269 	 * must drop the critical section, then re-acquire it when we go back
3270 	 * to the cache.  Since the critical section is released, we may be
3271 	 * preempted or migrate.  As such, make sure not to maintain any
3272 	 * thread-local state specific to the cache from prior to releasing
3273 	 * the critical section.
3274 	 */
3275 	lockfail = 0;
3276 	if (ZONE_TRYLOCK(zone) == 0) {
3277 		/* Record contention to size the buckets. */
3278 		ZONE_LOCK(zone);
3279 		lockfail = 1;
3280 	}
3281 
3282 	/* See if we lost the race to fill the cache. */
3283 	critical_enter();
3284 	cache = &zone->uz_cpu[curcpu];
3285 	if (cache->uc_allocbucket.ucb_bucket != NULL) {
3286 		ZONE_UNLOCK(zone);
3287 		return (true);
3288 	}
3289 
3290 	/*
3291 	 * Check the zone's cache of buckets.
3292 	 */
3293 	if (zone->uz_flags & UMA_ZONE_FIRSTTOUCH) {
3294 		domain = PCPU_GET(domain);
3295 		zdom = &zone->uz_domain[domain];
3296 	} else {
3297 		domain = UMA_ANYDOMAIN;
3298 		zdom = &zone->uz_domain[0];
3299 	}
3300 
3301 	if ((bucket = zone_fetch_bucket(zone, zdom)) != NULL) {
3302 		KASSERT(bucket->ub_cnt != 0,
3303 		    ("uma_zalloc_arg: Returning an empty bucket."));
3304 		cache_bucket_load_alloc(cache, bucket);
3305 		return (true);
3306 	}
3307 	/* We are no longer associated with this CPU. */
3308 	critical_exit();
3309 
3310 	/*
3311 	 * We bump the uz count when the cache size is insufficient to
3312 	 * handle the working set.
3313 	 */
3314 	if (lockfail && zone->uz_bucket_size < zone->uz_bucket_size_max)
3315 		zone->uz_bucket_size++;
3316 	ZONE_UNLOCK(zone);
3317 
3318 	/*
3319 	 * Fill a bucket and attempt to use it as the alloc bucket.
3320 	 */
3321 	bucket = zone_alloc_bucket(zone, udata, domain, flags);
3322 	CTR3(KTR_UMA, "uma_zalloc: zone %s(%p) bucket zone returned %p",
3323 	    zone->uz_name, zone, bucket);
3324 	if (bucket == NULL) {
3325 		critical_enter();
3326 		return (false);
3327 	}
3328 
3329 	/*
3330 	 * See if we lost the race or were migrated.  Cache the
3331 	 * initialized bucket to make this less likely or claim
3332 	 * the memory directly.
3333 	 */
3334 	ZONE_LOCK(zone);
3335 	critical_enter();
3336 	cache = &zone->uz_cpu[curcpu];
3337 	if (cache->uc_allocbucket.ucb_bucket == NULL &&
3338 	    ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) == 0 ||
3339 	    domain == PCPU_GET(domain))) {
3340 		cache_bucket_load_alloc(cache, bucket);
3341 		zdom->uzd_imax += bucket->ub_cnt;
3342 	} else if (zone->uz_bkt_count >= zone->uz_bkt_max) {
3343 		critical_exit();
3344 		ZONE_UNLOCK(zone);
3345 		bucket_drain(zone, bucket);
3346 		bucket_free(zone, bucket, udata);
3347 		critical_enter();
3348 		return (true);
3349 	} else
3350 		zone_put_bucket(zone, zdom, bucket, false);
3351 	ZONE_UNLOCK(zone);
3352 	return (true);
3353 }
3354 
3355 void *
3356 uma_zalloc_domain(uma_zone_t zone, void *udata, int domain, int flags)
3357 {
3358 
3359 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
3360 	random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
3361 
3362 	/* This is the fast path allocation */
3363 	CTR4(KTR_UMA, "uma_zalloc_domain zone %s(%p) domain %d flags %d",
3364 	    zone->uz_name, zone, domain, flags);
3365 
3366 	if (flags & M_WAITOK) {
3367 		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
3368 		    "uma_zalloc_domain: zone \"%s\"", zone->uz_name);
3369 	}
3370 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
3371 	    ("uma_zalloc_domain: called with spinlock or critical section held"));
3372 
3373 	return (zone_alloc_item(zone, udata, domain, flags));
3374 }
3375 
3376 /*
3377  * Find a slab with some space.  Prefer slabs that are partially used over those
3378  * that are totally full.  This helps to reduce fragmentation.
3379  *
3380  * If 'rr' is 1, search all domains starting from 'domain'.  Otherwise check
3381  * only 'domain'.
3382  */
3383 static uma_slab_t
3384 keg_first_slab(uma_keg_t keg, int domain, bool rr)
3385 {
3386 	uma_domain_t dom;
3387 	uma_slab_t slab;
3388 	int start;
3389 
3390 	KASSERT(domain >= 0 && domain < vm_ndomains,
3391 	    ("keg_first_slab: domain %d out of range", domain));
3392 	KEG_LOCK_ASSERT(keg, domain);
3393 
3394 	slab = NULL;
3395 	start = domain;
3396 	do {
3397 		dom = &keg->uk_domain[domain];
3398 		if ((slab = LIST_FIRST(&dom->ud_part_slab)) != NULL)
3399 			return (slab);
3400 		if ((slab = LIST_FIRST(&dom->ud_free_slab)) != NULL) {
3401 			LIST_REMOVE(slab, us_link);
3402 			dom->ud_free_slabs--;
3403 			LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
3404 			return (slab);
3405 		}
3406 		if (rr)
3407 			domain = (domain + 1) % vm_ndomains;
3408 	} while (domain != start);
3409 
3410 	return (NULL);
3411 }
3412 
3413 /*
3414  * Fetch an existing slab from a free or partial list.  Returns with the
3415  * keg domain lock held if a slab was found or unlocked if not.
3416  */
3417 static uma_slab_t
3418 keg_fetch_free_slab(uma_keg_t keg, int domain, bool rr, int flags)
3419 {
3420 	uma_slab_t slab;
3421 	uint32_t reserve;
3422 
3423 	/* HASH has a single free list. */
3424 	if ((keg->uk_flags & UMA_ZFLAG_HASH) != 0)
3425 		domain = 0;
3426 
3427 	KEG_LOCK(keg, domain);
3428 	reserve = (flags & M_USE_RESERVE) != 0 ? 0 : keg->uk_reserve;
3429 	if (keg->uk_domain[domain].ud_free_items <= reserve ||
3430 	    (slab = keg_first_slab(keg, domain, rr)) == NULL) {
3431 		KEG_UNLOCK(keg, domain);
3432 		return (NULL);
3433 	}
3434 	return (slab);
3435 }
3436 
3437 static uma_slab_t
3438 keg_fetch_slab(uma_keg_t keg, uma_zone_t zone, int rdomain, const int flags)
3439 {
3440 	struct vm_domainset_iter di;
3441 	uma_slab_t slab;
3442 	int aflags, domain;
3443 	bool rr;
3444 
3445 restart:
3446 	/*
3447 	 * Use the keg's policy if upper layers haven't already specified a
3448 	 * domain (as happens with first-touch zones).
3449 	 *
3450 	 * To avoid races we run the iterator with the keg lock held, but that
3451 	 * means that we cannot allow the vm_domainset layer to sleep.  Thus,
3452 	 * clear M_WAITOK and handle low memory conditions locally.
3453 	 */
3454 	rr = rdomain == UMA_ANYDOMAIN;
3455 	if (rr) {
3456 		aflags = (flags & ~M_WAITOK) | M_NOWAIT;
3457 		vm_domainset_iter_policy_ref_init(&di, &keg->uk_dr, &domain,
3458 		    &aflags);
3459 	} else {
3460 		aflags = flags;
3461 		domain = rdomain;
3462 	}
3463 
3464 	for (;;) {
3465 		slab = keg_fetch_free_slab(keg, domain, rr, flags);
3466 		if (slab != NULL)
3467 			return (slab);
3468 
3469 		/*
3470 		 * M_NOVM means don't ask at all!
3471 		 */
3472 		if (flags & M_NOVM)
3473 			break;
3474 
3475 		slab = keg_alloc_slab(keg, zone, domain, flags, aflags);
3476 		if (slab != NULL)
3477 			return (slab);
3478 		if (!rr && (flags & M_WAITOK) == 0)
3479 			break;
3480 		if (rr && vm_domainset_iter_policy(&di, &domain) != 0) {
3481 			if ((flags & M_WAITOK) != 0) {
3482 				vm_wait_doms(&keg->uk_dr.dr_policy->ds_mask);
3483 				goto restart;
3484 			}
3485 			break;
3486 		}
3487 	}
3488 
3489 	/*
3490 	 * We might not have been able to get a slab but another cpu
3491 	 * could have while we were unlocked.  Check again before we
3492 	 * fail.
3493 	 */
3494 	if ((slab = keg_fetch_free_slab(keg, domain, rr, flags)) != NULL)
3495 		return (slab);
3496 
3497 	return (NULL);
3498 }
3499 
3500 static void *
3501 slab_alloc_item(uma_keg_t keg, uma_slab_t slab)
3502 {
3503 	uma_domain_t dom;
3504 	void *item;
3505 	int freei;
3506 
3507 	KEG_LOCK_ASSERT(keg, slab->us_domain);
3508 
3509 	dom = &keg->uk_domain[slab->us_domain];
3510 	freei = BIT_FFS(keg->uk_ipers, &slab->us_free) - 1;
3511 	BIT_CLR(keg->uk_ipers, freei, &slab->us_free);
3512 	item = slab_item(slab, keg, freei);
3513 	slab->us_freecount--;
3514 	dom->ud_free_items--;
3515 
3516 	/*
3517 	 * Move this slab to the full list.  It must be on the partial list, so
3518 	 * we do not need to update the free slab count.  In particular,
3519 	 * keg_fetch_slab() always returns slabs on the partial list.
3520 	 */
3521 	if (slab->us_freecount == 0) {
3522 		LIST_REMOVE(slab, us_link);
3523 		LIST_INSERT_HEAD(&dom->ud_full_slab, slab, us_link);
3524 	}
3525 
3526 	return (item);
3527 }
3528 
3529 static int
3530 zone_import(void *arg, void **bucket, int max, int domain, int flags)
3531 {
3532 	uma_domain_t dom;
3533 	uma_zone_t zone;
3534 	uma_slab_t slab;
3535 	uma_keg_t keg;
3536 #ifdef NUMA
3537 	int stripe;
3538 #endif
3539 	int i;
3540 
3541 	zone = arg;
3542 	slab = NULL;
3543 	keg = zone->uz_keg;
3544 	/* Try to keep the buckets totally full */
3545 	for (i = 0; i < max; ) {
3546 		if ((slab = keg_fetch_slab(keg, zone, domain, flags)) == NULL)
3547 			break;
3548 #ifdef NUMA
3549 		stripe = howmany(max, vm_ndomains);
3550 #endif
3551 		dom = &keg->uk_domain[slab->us_domain];
3552 		while (slab->us_freecount && i < max) {
3553 			bucket[i++] = slab_alloc_item(keg, slab);
3554 			if (dom->ud_free_items <= keg->uk_reserve)
3555 				break;
3556 #ifdef NUMA
3557 			/*
3558 			 * If the zone is striped we pick a new slab for every
3559 			 * N allocations.  Eliminating this conditional will
3560 			 * instead pick a new domain for each bucket rather
3561 			 * than stripe within each bucket.  The current option
3562 			 * produces more fragmentation and requires more cpu
3563 			 * time but yields better distribution.
3564 			 */
3565 			if ((zone->uz_flags & UMA_ZONE_ROUNDROBIN) != 0 &&
3566 			    vm_ndomains > 1 && --stripe == 0)
3567 				break;
3568 #endif
3569 		}
3570 		KEG_UNLOCK(keg, slab->us_domain);
3571 		/* Don't block if we allocated any successfully. */
3572 		flags &= ~M_WAITOK;
3573 		flags |= M_NOWAIT;
3574 	}
3575 
3576 	return i;
3577 }
3578 
3579 static int
3580 zone_alloc_limit_hard(uma_zone_t zone, int count, int flags)
3581 {
3582 	uint64_t old, new, total, max;
3583 
3584 	/*
3585 	 * The hard case.  We're going to sleep because there were existing
3586 	 * sleepers or because we ran out of items.  This routine enforces
3587 	 * fairness by keeping fifo order.
3588 	 *
3589 	 * First release our ill gotten gains and make some noise.
3590 	 */
3591 	for (;;) {
3592 		zone_free_limit(zone, count);
3593 		zone_log_warning(zone);
3594 		zone_maxaction(zone);
3595 		if (flags & M_NOWAIT)
3596 			return (0);
3597 
3598 		/*
3599 		 * We need to allocate an item or set ourself as a sleeper
3600 		 * while the sleepq lock is held to avoid wakeup races.  This
3601 		 * is essentially a home rolled semaphore.
3602 		 */
3603 		sleepq_lock(&zone->uz_max_items);
3604 		old = zone->uz_items;
3605 		do {
3606 			MPASS(UZ_ITEMS_SLEEPERS(old) < UZ_ITEMS_SLEEPERS_MAX);
3607 			/* Cache the max since we will evaluate twice. */
3608 			max = zone->uz_max_items;
3609 			if (UZ_ITEMS_SLEEPERS(old) != 0 ||
3610 			    UZ_ITEMS_COUNT(old) >= max)
3611 				new = old + UZ_ITEMS_SLEEPER;
3612 			else
3613 				new = old + MIN(count, max - old);
3614 		} while (atomic_fcmpset_64(&zone->uz_items, &old, new) == 0);
3615 
3616 		/* We may have successfully allocated under the sleepq lock. */
3617 		if (UZ_ITEMS_SLEEPERS(new) == 0) {
3618 			sleepq_release(&zone->uz_max_items);
3619 			return (new - old);
3620 		}
3621 
3622 		/*
3623 		 * This is in a different cacheline from uz_items so that we
3624 		 * don't constantly invalidate the fastpath cacheline when we
3625 		 * adjust item counts.  This could be limited to toggling on
3626 		 * transitions.
3627 		 */
3628 		atomic_add_32(&zone->uz_sleepers, 1);
3629 		atomic_add_64(&zone->uz_sleeps, 1);
3630 
3631 		/*
3632 		 * We have added ourselves as a sleeper.  The sleepq lock
3633 		 * protects us from wakeup races.  Sleep now and then retry.
3634 		 */
3635 		sleepq_add(&zone->uz_max_items, NULL, "zonelimit", 0, 0);
3636 		sleepq_wait(&zone->uz_max_items, PVM);
3637 
3638 		/*
3639 		 * After wakeup, remove ourselves as a sleeper and try
3640 		 * again.  We no longer have the sleepq lock for protection.
3641 		 *
3642 		 * Subract ourselves as a sleeper while attempting to add
3643 		 * our count.
3644 		 */
3645 		atomic_subtract_32(&zone->uz_sleepers, 1);
3646 		old = atomic_fetchadd_64(&zone->uz_items,
3647 		    -(UZ_ITEMS_SLEEPER - count));
3648 		/* We're no longer a sleeper. */
3649 		old -= UZ_ITEMS_SLEEPER;
3650 
3651 		/*
3652 		 * If we're still at the limit, restart.  Notably do not
3653 		 * block on other sleepers.  Cache the max value to protect
3654 		 * against changes via sysctl.
3655 		 */
3656 		total = UZ_ITEMS_COUNT(old);
3657 		max = zone->uz_max_items;
3658 		if (total >= max)
3659 			continue;
3660 		/* Truncate if necessary, otherwise wake other sleepers. */
3661 		if (total + count > max) {
3662 			zone_free_limit(zone, total + count - max);
3663 			count = max - total;
3664 		} else if (total + count < max && UZ_ITEMS_SLEEPERS(old) != 0)
3665 			wakeup_one(&zone->uz_max_items);
3666 
3667 		return (count);
3668 	}
3669 }
3670 
3671 /*
3672  * Allocate 'count' items from our max_items limit.  Returns the number
3673  * available.  If M_NOWAIT is not specified it will sleep until at least
3674  * one item can be allocated.
3675  */
3676 static int
3677 zone_alloc_limit(uma_zone_t zone, int count, int flags)
3678 {
3679 	uint64_t old;
3680 	uint64_t max;
3681 
3682 	max = zone->uz_max_items;
3683 	MPASS(max > 0);
3684 
3685 	/*
3686 	 * We expect normal allocations to succeed with a simple
3687 	 * fetchadd.
3688 	 */
3689 	old = atomic_fetchadd_64(&zone->uz_items, count);
3690 	if (__predict_true(old + count <= max))
3691 		return (count);
3692 
3693 	/*
3694 	 * If we had some items and no sleepers just return the
3695 	 * truncated value.  We have to release the excess space
3696 	 * though because that may wake sleepers who weren't woken
3697 	 * because we were temporarily over the limit.
3698 	 */
3699 	if (old < max) {
3700 		zone_free_limit(zone, (old + count) - max);
3701 		return (max - old);
3702 	}
3703 	return (zone_alloc_limit_hard(zone, count, flags));
3704 }
3705 
3706 /*
3707  * Free a number of items back to the limit.
3708  */
3709 static void
3710 zone_free_limit(uma_zone_t zone, int count)
3711 {
3712 	uint64_t old;
3713 
3714 	MPASS(count > 0);
3715 
3716 	/*
3717 	 * In the common case we either have no sleepers or
3718 	 * are still over the limit and can just return.
3719 	 */
3720 	old = atomic_fetchadd_64(&zone->uz_items, -count);
3721 	if (__predict_true(UZ_ITEMS_SLEEPERS(old) == 0 ||
3722 	   UZ_ITEMS_COUNT(old) - count >= zone->uz_max_items))
3723 		return;
3724 
3725 	/*
3726 	 * Moderate the rate of wakeups.  Sleepers will continue
3727 	 * to generate wakeups if necessary.
3728 	 */
3729 	wakeup_one(&zone->uz_max_items);
3730 }
3731 
3732 static uma_bucket_t
3733 zone_alloc_bucket(uma_zone_t zone, void *udata, int domain, int flags)
3734 {
3735 	uma_bucket_t bucket;
3736 	int maxbucket, cnt;
3737 
3738 	CTR3(KTR_UMA, "zone_alloc_bucket zone %s(%p) domain %d", zone->uz_name,
3739 	    zone, domain);
3740 
3741 	/* Avoid allocs targeting empty domains. */
3742 	if (domain != UMA_ANYDOMAIN && VM_DOMAIN_EMPTY(domain))
3743 		domain = UMA_ANYDOMAIN;
3744 
3745 	if (zone->uz_max_items > 0)
3746 		maxbucket = zone_alloc_limit(zone, zone->uz_bucket_size,
3747 		    M_NOWAIT);
3748 	else
3749 		maxbucket = zone->uz_bucket_size;
3750 	if (maxbucket == 0)
3751 		return (false);
3752 
3753 	/* Don't wait for buckets, preserve caller's NOVM setting. */
3754 	bucket = bucket_alloc(zone, udata, M_NOWAIT | (flags & M_NOVM));
3755 	if (bucket == NULL) {
3756 		cnt = 0;
3757 		goto out;
3758 	}
3759 
3760 	bucket->ub_cnt = zone->uz_import(zone->uz_arg, bucket->ub_bucket,
3761 	    MIN(maxbucket, bucket->ub_entries), domain, flags);
3762 
3763 	/*
3764 	 * Initialize the memory if necessary.
3765 	 */
3766 	if (bucket->ub_cnt != 0 && zone->uz_init != NULL) {
3767 		int i;
3768 
3769 		for (i = 0; i < bucket->ub_cnt; i++)
3770 			if (zone->uz_init(bucket->ub_bucket[i], zone->uz_size,
3771 			    flags) != 0)
3772 				break;
3773 		/*
3774 		 * If we couldn't initialize the whole bucket, put the
3775 		 * rest back onto the freelist.
3776 		 */
3777 		if (i != bucket->ub_cnt) {
3778 			zone->uz_release(zone->uz_arg, &bucket->ub_bucket[i],
3779 			    bucket->ub_cnt - i);
3780 #ifdef INVARIANTS
3781 			bzero(&bucket->ub_bucket[i],
3782 			    sizeof(void *) * (bucket->ub_cnt - i));
3783 #endif
3784 			bucket->ub_cnt = i;
3785 		}
3786 	}
3787 
3788 	cnt = bucket->ub_cnt;
3789 	if (bucket->ub_cnt == 0) {
3790 		bucket_free(zone, bucket, udata);
3791 		counter_u64_add(zone->uz_fails, 1);
3792 		bucket = NULL;
3793 	}
3794 out:
3795 	if (zone->uz_max_items > 0 && cnt < maxbucket)
3796 		zone_free_limit(zone, maxbucket - cnt);
3797 
3798 	return (bucket);
3799 }
3800 
3801 /*
3802  * Allocates a single item from a zone.
3803  *
3804  * Arguments
3805  *	zone   The zone to alloc for.
3806  *	udata  The data to be passed to the constructor.
3807  *	domain The domain to allocate from or UMA_ANYDOMAIN.
3808  *	flags  M_WAITOK, M_NOWAIT, M_ZERO.
3809  *
3810  * Returns
3811  *	NULL if there is no memory and M_NOWAIT is set
3812  *	An item if successful
3813  */
3814 
3815 static void *
3816 zone_alloc_item(uma_zone_t zone, void *udata, int domain, int flags)
3817 {
3818 	void *item;
3819 
3820 	if (zone->uz_max_items > 0 && zone_alloc_limit(zone, 1, flags) == 0)
3821 		return (NULL);
3822 
3823 	/* Avoid allocs targeting empty domains. */
3824 	if (domain != UMA_ANYDOMAIN && VM_DOMAIN_EMPTY(domain))
3825 		domain = UMA_ANYDOMAIN;
3826 
3827 	if (zone->uz_import(zone->uz_arg, &item, 1, domain, flags) != 1)
3828 		goto fail_cnt;
3829 
3830 	/*
3831 	 * We have to call both the zone's init (not the keg's init)
3832 	 * and the zone's ctor.  This is because the item is going from
3833 	 * a keg slab directly to the user, and the user is expecting it
3834 	 * to be both zone-init'd as well as zone-ctor'd.
3835 	 */
3836 	if (zone->uz_init != NULL) {
3837 		if (zone->uz_init(item, zone->uz_size, flags) != 0) {
3838 			zone_free_item(zone, item, udata, SKIP_FINI | SKIP_CNT);
3839 			goto fail_cnt;
3840 		}
3841 	}
3842 	item = item_ctor(zone, zone->uz_flags, zone->uz_size, udata, flags,
3843 	    item);
3844 	if (item == NULL)
3845 		goto fail;
3846 
3847 	counter_u64_add(zone->uz_allocs, 1);
3848 	CTR3(KTR_UMA, "zone_alloc_item item %p from %s(%p)", item,
3849 	    zone->uz_name, zone);
3850 
3851 	return (item);
3852 
3853 fail_cnt:
3854 	counter_u64_add(zone->uz_fails, 1);
3855 fail:
3856 	if (zone->uz_max_items > 0)
3857 		zone_free_limit(zone, 1);
3858 	CTR2(KTR_UMA, "zone_alloc_item failed from %s(%p)",
3859 	    zone->uz_name, zone);
3860 
3861 	return (NULL);
3862 }
3863 
3864 /* See uma.h */
3865 void
3866 uma_zfree_smr(uma_zone_t zone, void *item)
3867 {
3868 	uma_cache_t cache;
3869 	uma_cache_bucket_t bucket;
3870 	int domain, itemdomain, uz_flags;
3871 
3872 #ifdef UMA_ZALLOC_DEBUG
3873 	KASSERT((zone->uz_flags & UMA_ZONE_SMR) != 0,
3874 	    ("uma_zfree_smr: called with non-SMR zone.\n"));
3875 	KASSERT(item != NULL, ("uma_zfree_smr: Called with NULL pointer."));
3876 	if (uma_zfree_debug(zone, item, NULL) == EJUSTRETURN)
3877 		return;
3878 #endif
3879 	cache = &zone->uz_cpu[curcpu];
3880 	uz_flags = cache_uz_flags(cache);
3881 	domain = itemdomain = 0;
3882 #ifdef NUMA
3883 	if ((uz_flags & UMA_ZONE_FIRSTTOUCH) != 0)
3884 		itemdomain = _vm_phys_domain(pmap_kextract((vm_offset_t)item));
3885 #endif
3886 	critical_enter();
3887 	do {
3888 		cache = &zone->uz_cpu[curcpu];
3889 		/* SMR Zones must free to the free bucket. */
3890 		bucket = &cache->uc_freebucket;
3891 #ifdef NUMA
3892 		domain = PCPU_GET(domain);
3893 		if ((uz_flags & UMA_ZONE_FIRSTTOUCH) != 0 &&
3894 		    domain != itemdomain) {
3895 			bucket = &cache->uc_crossbucket;
3896 		}
3897 #endif
3898 		if (__predict_true(bucket->ucb_cnt < bucket->ucb_entries)) {
3899 			cache_bucket_push(cache, bucket, item);
3900 			critical_exit();
3901 			return;
3902 		}
3903 	} while (cache_free(zone, cache, NULL, item, itemdomain));
3904 	critical_exit();
3905 
3906 	/*
3907 	 * If nothing else caught this, we'll just do an internal free.
3908 	 */
3909 	zone_free_item(zone, item, NULL, SKIP_NONE);
3910 }
3911 
3912 /* See uma.h */
3913 void
3914 uma_zfree_arg(uma_zone_t zone, void *item, void *udata)
3915 {
3916 	uma_cache_t cache;
3917 	uma_cache_bucket_t bucket;
3918 	int domain, itemdomain, uz_flags;
3919 
3920 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
3921 	random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
3922 
3923 	CTR2(KTR_UMA, "uma_zfree_arg zone %s(%p)", zone->uz_name, zone);
3924 
3925 #ifdef UMA_ZALLOC_DEBUG
3926 	KASSERT((zone->uz_flags & UMA_ZONE_SMR) == 0,
3927 	    ("uma_zfree_arg: called with SMR zone.\n"));
3928 	if (uma_zfree_debug(zone, item, udata) == EJUSTRETURN)
3929 		return;
3930 #endif
3931         /* uma_zfree(..., NULL) does nothing, to match free(9). */
3932         if (item == NULL)
3933                 return;
3934 
3935 	/*
3936 	 * We are accessing the per-cpu cache without a critical section to
3937 	 * fetch size and flags.  This is acceptable, if we are preempted we
3938 	 * will simply read another cpu's line.
3939 	 */
3940 	cache = &zone->uz_cpu[curcpu];
3941 	uz_flags = cache_uz_flags(cache);
3942 	if (UMA_ALWAYS_CTORDTOR ||
3943 	    __predict_false((uz_flags & UMA_ZFLAG_CTORDTOR) != 0))
3944 		item_dtor(zone, item, cache_uz_size(cache), udata, SKIP_NONE);
3945 
3946 	/*
3947 	 * The race here is acceptable.  If we miss it we'll just have to wait
3948 	 * a little longer for the limits to be reset.
3949 	 */
3950 	if (__predict_false(uz_flags & UMA_ZFLAG_LIMIT)) {
3951 		if (zone->uz_sleepers > 0)
3952 			goto zfree_item;
3953 	}
3954 
3955 	/*
3956 	 * If possible, free to the per-CPU cache.  There are two
3957 	 * requirements for safe access to the per-CPU cache: (1) the thread
3958 	 * accessing the cache must not be preempted or yield during access,
3959 	 * and (2) the thread must not migrate CPUs without switching which
3960 	 * cache it accesses.  We rely on a critical section to prevent
3961 	 * preemption and migration.  We release the critical section in
3962 	 * order to acquire the zone mutex if we are unable to free to the
3963 	 * current cache; when we re-acquire the critical section, we must
3964 	 * detect and handle migration if it has occurred.
3965 	 */
3966 	domain = itemdomain = 0;
3967 #ifdef NUMA
3968 	if ((uz_flags & UMA_ZONE_FIRSTTOUCH) != 0)
3969 		itemdomain = _vm_phys_domain(pmap_kextract((vm_offset_t)item));
3970 #endif
3971 	critical_enter();
3972 	do {
3973 		cache = &zone->uz_cpu[curcpu];
3974 		/*
3975 		 * Try to free into the allocbucket first to give LIFO
3976 		 * ordering for cache-hot datastructures.  Spill over
3977 		 * into the freebucket if necessary.  Alloc will swap
3978 		 * them if one runs dry.
3979 		 */
3980 		bucket = &cache->uc_allocbucket;
3981 #ifdef NUMA
3982 		domain = PCPU_GET(domain);
3983 		if ((uz_flags & UMA_ZONE_FIRSTTOUCH) != 0 &&
3984 		    domain != itemdomain) {
3985 			bucket = &cache->uc_crossbucket;
3986 		} else
3987 #endif
3988 		if (bucket->ucb_cnt >= bucket->ucb_entries)
3989 			bucket = &cache->uc_freebucket;
3990 		if (__predict_true(bucket->ucb_cnt < bucket->ucb_entries)) {
3991 			cache_bucket_push(cache, bucket, item);
3992 			critical_exit();
3993 			return;
3994 		}
3995 	} while (cache_free(zone, cache, udata, item, itemdomain));
3996 	critical_exit();
3997 
3998 	/*
3999 	 * If nothing else caught this, we'll just do an internal free.
4000 	 */
4001 zfree_item:
4002 	zone_free_item(zone, item, udata, SKIP_DTOR);
4003 }
4004 
4005 #ifdef NUMA
4006 /*
4007  * sort crossdomain free buckets to domain correct buckets and cache
4008  * them.
4009  */
4010 static void
4011 zone_free_cross(uma_zone_t zone, uma_bucket_t bucket, void *udata)
4012 {
4013 	struct uma_bucketlist fullbuckets;
4014 	uma_zone_domain_t zdom;
4015 	uma_bucket_t b;
4016 	smr_seq_t seq;
4017 	void *item;
4018 	int domain;
4019 
4020 	CTR3(KTR_UMA,
4021 	    "uma_zfree: zone %s(%p) draining cross bucket %p",
4022 	    zone->uz_name, zone, bucket);
4023 
4024 	STAILQ_INIT(&fullbuckets);
4025 
4026 	/*
4027 	 * To avoid having ndomain * ndomain buckets for sorting we have a
4028 	 * lock on the current crossfree bucket.  A full matrix with
4029 	 * per-domain locking could be used if necessary.
4030 	 */
4031 	ZONE_CROSS_LOCK(zone);
4032 
4033 	/*
4034 	 * It is possible for buckets to arrive here out of order so we fetch
4035 	 * the current smr seq rather than accepting the bucket's.
4036 	 */
4037 	seq = SMR_SEQ_INVALID;
4038 	if ((zone->uz_flags & UMA_ZONE_SMR) != 0)
4039 		seq = smr_current(zone->uz_smr);
4040 	while (bucket->ub_cnt > 0) {
4041 		item = bucket->ub_bucket[bucket->ub_cnt - 1];
4042 		domain = _vm_phys_domain(pmap_kextract((vm_offset_t)item));
4043 		zdom = &zone->uz_domain[domain];
4044 		if (zdom->uzd_cross == NULL) {
4045 			zdom->uzd_cross = bucket_alloc(zone, udata, M_NOWAIT);
4046 			if (zdom->uzd_cross == NULL)
4047 				break;
4048 		}
4049 		b = zdom->uzd_cross;
4050 		b->ub_bucket[b->ub_cnt++] = item;
4051 		b->ub_seq = seq;
4052 		if (b->ub_cnt == b->ub_entries) {
4053 			STAILQ_INSERT_HEAD(&fullbuckets, b, ub_link);
4054 			zdom->uzd_cross = NULL;
4055 		}
4056 		bucket->ub_cnt--;
4057 	}
4058 	ZONE_CROSS_UNLOCK(zone);
4059 	if (!STAILQ_EMPTY(&fullbuckets)) {
4060 		ZONE_LOCK(zone);
4061 		while ((b = STAILQ_FIRST(&fullbuckets)) != NULL) {
4062 			STAILQ_REMOVE_HEAD(&fullbuckets, ub_link);
4063 			if (zone->uz_bkt_count >= zone->uz_bkt_max) {
4064 				ZONE_UNLOCK(zone);
4065 				bucket_drain(zone, b);
4066 				bucket_free(zone, b, udata);
4067 				ZONE_LOCK(zone);
4068 			} else {
4069 				domain = _vm_phys_domain(
4070 				    pmap_kextract(
4071 				    (vm_offset_t)b->ub_bucket[0]));
4072 				zdom = &zone->uz_domain[domain];
4073 				zone_put_bucket(zone, zdom, b, true);
4074 			}
4075 		}
4076 		ZONE_UNLOCK(zone);
4077 	}
4078 	if (bucket->ub_cnt != 0)
4079 		bucket_drain(zone, bucket);
4080 	bucket->ub_seq = SMR_SEQ_INVALID;
4081 	bucket_free(zone, bucket, udata);
4082 }
4083 #endif
4084 
4085 static void
4086 zone_free_bucket(uma_zone_t zone, uma_bucket_t bucket, void *udata,
4087     int domain, int itemdomain)
4088 {
4089 	uma_zone_domain_t zdom;
4090 
4091 #ifdef NUMA
4092 	/*
4093 	 * Buckets coming from the wrong domain will be entirely for the
4094 	 * only other domain on two domain systems.  In this case we can
4095 	 * simply cache them.  Otherwise we need to sort them back to
4096 	 * correct domains.
4097 	 */
4098 	if (domain != itemdomain && vm_ndomains > 2) {
4099 		zone_free_cross(zone, bucket, udata);
4100 		return;
4101 	}
4102 #endif
4103 
4104 	/*
4105 	 * Attempt to save the bucket in the zone's domain bucket cache.
4106 	 *
4107 	 * We bump the uz count when the cache size is insufficient to
4108 	 * handle the working set.
4109 	 */
4110 	if (ZONE_TRYLOCK(zone) == 0) {
4111 		/* Record contention to size the buckets. */
4112 		ZONE_LOCK(zone);
4113 		if (zone->uz_bucket_size < zone->uz_bucket_size_max)
4114 			zone->uz_bucket_size++;
4115 	}
4116 
4117 	CTR3(KTR_UMA,
4118 	    "uma_zfree: zone %s(%p) putting bucket %p on free list",
4119 	    zone->uz_name, zone, bucket);
4120 	/* ub_cnt is pointing to the last free item */
4121 	KASSERT(bucket->ub_cnt == bucket->ub_entries,
4122 	    ("uma_zfree: Attempting to insert partial  bucket onto the full list.\n"));
4123 	if (zone->uz_bkt_count >= zone->uz_bkt_max) {
4124 		ZONE_UNLOCK(zone);
4125 		bucket_drain(zone, bucket);
4126 		bucket_free(zone, bucket, udata);
4127 	} else {
4128 		zdom = &zone->uz_domain[itemdomain];
4129 		zone_put_bucket(zone, zdom, bucket, true);
4130 		ZONE_UNLOCK(zone);
4131 	}
4132 }
4133 
4134 /*
4135  * Populate a free or cross bucket for the current cpu cache.  Free any
4136  * existing full bucket either to the zone cache or back to the slab layer.
4137  *
4138  * Enters and returns in a critical section.  false return indicates that
4139  * we can not satisfy this free in the cache layer.  true indicates that
4140  * the caller should retry.
4141  */
4142 static __noinline bool
4143 cache_free(uma_zone_t zone, uma_cache_t cache, void *udata, void *item,
4144     int itemdomain)
4145 {
4146 	uma_cache_bucket_t cbucket;
4147 	uma_bucket_t newbucket, bucket;
4148 	int domain;
4149 
4150 	CRITICAL_ASSERT(curthread);
4151 
4152 	if (zone->uz_bucket_size == 0)
4153 		return false;
4154 
4155 	cache = &zone->uz_cpu[curcpu];
4156 	newbucket = NULL;
4157 
4158 	/*
4159 	 * FIRSTTOUCH domains need to free to the correct zdom.  When
4160 	 * enabled this is the zdom of the item.   The bucket is the
4161 	 * cross bucket if the current domain and itemdomain do not match.
4162 	 */
4163 	cbucket = &cache->uc_freebucket;
4164 #ifdef NUMA
4165 	if ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) != 0) {
4166 		domain = PCPU_GET(domain);
4167 		if (domain != itemdomain) {
4168 			cbucket = &cache->uc_crossbucket;
4169 			if (cbucket->ucb_cnt != 0)
4170 				atomic_add_64(&zone->uz_xdomain,
4171 				    cbucket->ucb_cnt);
4172 		}
4173 	} else
4174 #endif
4175 		itemdomain = domain = 0;
4176 	bucket = cache_bucket_unload(cbucket);
4177 
4178 	/* We are no longer associated with this CPU. */
4179 	critical_exit();
4180 
4181 	/*
4182 	 * Don't let SMR zones operate without a free bucket.  Force
4183 	 * a synchronize and re-use this one.  We will only degrade
4184 	 * to a synchronize every bucket_size items rather than every
4185 	 * item if we fail to allocate a bucket.
4186 	 */
4187 	if ((zone->uz_flags & UMA_ZONE_SMR) != 0) {
4188 		if (bucket != NULL)
4189 			bucket->ub_seq = smr_advance(zone->uz_smr);
4190 		newbucket = bucket_alloc(zone, udata, M_NOWAIT);
4191 		if (newbucket == NULL && bucket != NULL) {
4192 			bucket_drain(zone, bucket);
4193 			newbucket = bucket;
4194 			bucket = NULL;
4195 		}
4196 	} else if (!bucketdisable)
4197 		newbucket = bucket_alloc(zone, udata, M_NOWAIT);
4198 
4199 	if (bucket != NULL)
4200 		zone_free_bucket(zone, bucket, udata, domain, itemdomain);
4201 
4202 	critical_enter();
4203 	if ((bucket = newbucket) == NULL)
4204 		return (false);
4205 	cache = &zone->uz_cpu[curcpu];
4206 #ifdef NUMA
4207 	/*
4208 	 * Check to see if we should be populating the cross bucket.  If it
4209 	 * is already populated we will fall through and attempt to populate
4210 	 * the free bucket.
4211 	 */
4212 	if ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) != 0) {
4213 		domain = PCPU_GET(domain);
4214 		if (domain != itemdomain &&
4215 		    cache->uc_crossbucket.ucb_bucket == NULL) {
4216 			cache_bucket_load_cross(cache, bucket);
4217 			return (true);
4218 		}
4219 	}
4220 #endif
4221 	/*
4222 	 * We may have lost the race to fill the bucket or switched CPUs.
4223 	 */
4224 	if (cache->uc_freebucket.ucb_bucket != NULL) {
4225 		critical_exit();
4226 		bucket_free(zone, bucket, udata);
4227 		critical_enter();
4228 	} else
4229 		cache_bucket_load_free(cache, bucket);
4230 
4231 	return (true);
4232 }
4233 
4234 void
4235 uma_zfree_domain(uma_zone_t zone, void *item, void *udata)
4236 {
4237 
4238 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
4239 	random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
4240 
4241 	CTR2(KTR_UMA, "uma_zfree_domain zone %s(%p)", zone->uz_name, zone);
4242 
4243 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
4244 	    ("uma_zfree_domain: called with spinlock or critical section held"));
4245 
4246         /* uma_zfree(..., NULL) does nothing, to match free(9). */
4247         if (item == NULL)
4248                 return;
4249 	zone_free_item(zone, item, udata, SKIP_NONE);
4250 }
4251 
4252 static void
4253 slab_free_item(uma_zone_t zone, uma_slab_t slab, void *item)
4254 {
4255 	uma_keg_t keg;
4256 	uma_domain_t dom;
4257 	int freei;
4258 
4259 	keg = zone->uz_keg;
4260 	KEG_LOCK_ASSERT(keg, slab->us_domain);
4261 
4262 	/* Do we need to remove from any lists? */
4263 	dom = &keg->uk_domain[slab->us_domain];
4264 	if (slab->us_freecount + 1 == keg->uk_ipers) {
4265 		LIST_REMOVE(slab, us_link);
4266 		LIST_INSERT_HEAD(&dom->ud_free_slab, slab, us_link);
4267 		dom->ud_free_slabs++;
4268 	} else if (slab->us_freecount == 0) {
4269 		LIST_REMOVE(slab, us_link);
4270 		LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
4271 	}
4272 
4273 	/* Slab management. */
4274 	freei = slab_item_index(slab, keg, item);
4275 	BIT_SET(keg->uk_ipers, freei, &slab->us_free);
4276 	slab->us_freecount++;
4277 
4278 	/* Keg statistics. */
4279 	dom->ud_free_items++;
4280 }
4281 
4282 static void
4283 zone_release(void *arg, void **bucket, int cnt)
4284 {
4285 	struct mtx *lock;
4286 	uma_zone_t zone;
4287 	uma_slab_t slab;
4288 	uma_keg_t keg;
4289 	uint8_t *mem;
4290 	void *item;
4291 	int i;
4292 
4293 	zone = arg;
4294 	keg = zone->uz_keg;
4295 	lock = NULL;
4296 	if (__predict_false((zone->uz_flags & UMA_ZFLAG_HASH) != 0))
4297 		lock = KEG_LOCK(keg, 0);
4298 	for (i = 0; i < cnt; i++) {
4299 		item = bucket[i];
4300 		if (__predict_true((zone->uz_flags & UMA_ZFLAG_VTOSLAB) != 0)) {
4301 			slab = vtoslab((vm_offset_t)item);
4302 		} else {
4303 			mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
4304 			if ((zone->uz_flags & UMA_ZFLAG_HASH) != 0)
4305 				slab = hash_sfind(&keg->uk_hash, mem);
4306 			else
4307 				slab = (uma_slab_t)(mem + keg->uk_pgoff);
4308 		}
4309 		if (lock != KEG_LOCKPTR(keg, slab->us_domain)) {
4310 			if (lock != NULL)
4311 				mtx_unlock(lock);
4312 			lock = KEG_LOCK(keg, slab->us_domain);
4313 		}
4314 		slab_free_item(zone, slab, item);
4315 	}
4316 	if (lock != NULL)
4317 		mtx_unlock(lock);
4318 }
4319 
4320 /*
4321  * Frees a single item to any zone.
4322  *
4323  * Arguments:
4324  *	zone   The zone to free to
4325  *	item   The item we're freeing
4326  *	udata  User supplied data for the dtor
4327  *	skip   Skip dtors and finis
4328  */
4329 static void
4330 zone_free_item(uma_zone_t zone, void *item, void *udata, enum zfreeskip skip)
4331 {
4332 
4333 	/*
4334 	 * If a free is sent directly to an SMR zone we have to
4335 	 * synchronize immediately because the item can instantly
4336 	 * be reallocated. This should only happen in degenerate
4337 	 * cases when no memory is available for per-cpu caches.
4338 	 */
4339 	if ((zone->uz_flags & UMA_ZONE_SMR) != 0 && skip == SKIP_NONE)
4340 		smr_synchronize(zone->uz_smr);
4341 
4342 	item_dtor(zone, item, zone->uz_size, udata, skip);
4343 
4344 	if (skip < SKIP_FINI && zone->uz_fini)
4345 		zone->uz_fini(item, zone->uz_size);
4346 
4347 	zone->uz_release(zone->uz_arg, &item, 1);
4348 
4349 	if (skip & SKIP_CNT)
4350 		return;
4351 
4352 	counter_u64_add(zone->uz_frees, 1);
4353 
4354 	if (zone->uz_max_items > 0)
4355 		zone_free_limit(zone, 1);
4356 }
4357 
4358 /* See uma.h */
4359 int
4360 uma_zone_set_max(uma_zone_t zone, int nitems)
4361 {
4362 	struct uma_bucket_zone *ubz;
4363 	int count;
4364 
4365 	/*
4366 	 * XXX This can misbehave if the zone has any allocations with
4367 	 * no limit and a limit is imposed.  There is currently no
4368 	 * way to clear a limit.
4369 	 */
4370 	ZONE_LOCK(zone);
4371 	ubz = bucket_zone_max(zone, nitems);
4372 	count = ubz != NULL ? ubz->ubz_entries : 0;
4373 	zone->uz_bucket_size_max = zone->uz_bucket_size = count;
4374 	if (zone->uz_bucket_size_min > zone->uz_bucket_size_max)
4375 		zone->uz_bucket_size_min = zone->uz_bucket_size_max;
4376 	zone->uz_max_items = nitems;
4377 	zone->uz_flags |= UMA_ZFLAG_LIMIT;
4378 	zone_update_caches(zone);
4379 	/* We may need to wake waiters. */
4380 	wakeup(&zone->uz_max_items);
4381 	ZONE_UNLOCK(zone);
4382 
4383 	return (nitems);
4384 }
4385 
4386 /* See uma.h */
4387 void
4388 uma_zone_set_maxcache(uma_zone_t zone, int nitems)
4389 {
4390 	struct uma_bucket_zone *ubz;
4391 	int bpcpu;
4392 
4393 	ZONE_LOCK(zone);
4394 	ubz = bucket_zone_max(zone, nitems);
4395 	if (ubz != NULL) {
4396 		bpcpu = 2;
4397 		if ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) != 0)
4398 			/* Count the cross-domain bucket. */
4399 			bpcpu++;
4400 		nitems -= ubz->ubz_entries * bpcpu * mp_ncpus;
4401 		zone->uz_bucket_size_max = ubz->ubz_entries;
4402 	} else {
4403 		zone->uz_bucket_size_max = zone->uz_bucket_size = 0;
4404 	}
4405 	if (zone->uz_bucket_size_min > zone->uz_bucket_size_max)
4406 		zone->uz_bucket_size_min = zone->uz_bucket_size_max;
4407 	zone->uz_bkt_max = nitems;
4408 	ZONE_UNLOCK(zone);
4409 }
4410 
4411 /* See uma.h */
4412 int
4413 uma_zone_get_max(uma_zone_t zone)
4414 {
4415 	int nitems;
4416 
4417 	nitems = atomic_load_64(&zone->uz_max_items);
4418 
4419 	return (nitems);
4420 }
4421 
4422 /* See uma.h */
4423 void
4424 uma_zone_set_warning(uma_zone_t zone, const char *warning)
4425 {
4426 
4427 	ZONE_ASSERT_COLD(zone);
4428 	zone->uz_warning = warning;
4429 }
4430 
4431 /* See uma.h */
4432 void
4433 uma_zone_set_maxaction(uma_zone_t zone, uma_maxaction_t maxaction)
4434 {
4435 
4436 	ZONE_ASSERT_COLD(zone);
4437 	TASK_INIT(&zone->uz_maxaction, 0, (task_fn_t *)maxaction, zone);
4438 }
4439 
4440 /* See uma.h */
4441 int
4442 uma_zone_get_cur(uma_zone_t zone)
4443 {
4444 	int64_t nitems;
4445 	u_int i;
4446 
4447 	nitems = 0;
4448 	if (zone->uz_allocs != EARLY_COUNTER && zone->uz_frees != EARLY_COUNTER)
4449 		nitems = counter_u64_fetch(zone->uz_allocs) -
4450 		    counter_u64_fetch(zone->uz_frees);
4451 	CPU_FOREACH(i)
4452 		nitems += atomic_load_64(&zone->uz_cpu[i].uc_allocs) -
4453 		    atomic_load_64(&zone->uz_cpu[i].uc_frees);
4454 
4455 	return (nitems < 0 ? 0 : nitems);
4456 }
4457 
4458 static uint64_t
4459 uma_zone_get_allocs(uma_zone_t zone)
4460 {
4461 	uint64_t nitems;
4462 	u_int i;
4463 
4464 	nitems = 0;
4465 	if (zone->uz_allocs != EARLY_COUNTER)
4466 		nitems = counter_u64_fetch(zone->uz_allocs);
4467 	CPU_FOREACH(i)
4468 		nitems += atomic_load_64(&zone->uz_cpu[i].uc_allocs);
4469 
4470 	return (nitems);
4471 }
4472 
4473 static uint64_t
4474 uma_zone_get_frees(uma_zone_t zone)
4475 {
4476 	uint64_t nitems;
4477 	u_int i;
4478 
4479 	nitems = 0;
4480 	if (zone->uz_frees != EARLY_COUNTER)
4481 		nitems = counter_u64_fetch(zone->uz_frees);
4482 	CPU_FOREACH(i)
4483 		nitems += atomic_load_64(&zone->uz_cpu[i].uc_frees);
4484 
4485 	return (nitems);
4486 }
4487 
4488 #ifdef INVARIANTS
4489 /* Used only for KEG_ASSERT_COLD(). */
4490 static uint64_t
4491 uma_keg_get_allocs(uma_keg_t keg)
4492 {
4493 	uma_zone_t z;
4494 	uint64_t nitems;
4495 
4496 	nitems = 0;
4497 	LIST_FOREACH(z, &keg->uk_zones, uz_link)
4498 		nitems += uma_zone_get_allocs(z);
4499 
4500 	return (nitems);
4501 }
4502 #endif
4503 
4504 /* See uma.h */
4505 void
4506 uma_zone_set_init(uma_zone_t zone, uma_init uminit)
4507 {
4508 	uma_keg_t keg;
4509 
4510 	KEG_GET(zone, keg);
4511 	KEG_ASSERT_COLD(keg);
4512 	keg->uk_init = uminit;
4513 }
4514 
4515 /* See uma.h */
4516 void
4517 uma_zone_set_fini(uma_zone_t zone, uma_fini fini)
4518 {
4519 	uma_keg_t keg;
4520 
4521 	KEG_GET(zone, keg);
4522 	KEG_ASSERT_COLD(keg);
4523 	keg->uk_fini = fini;
4524 }
4525 
4526 /* See uma.h */
4527 void
4528 uma_zone_set_zinit(uma_zone_t zone, uma_init zinit)
4529 {
4530 
4531 	ZONE_ASSERT_COLD(zone);
4532 	zone->uz_init = zinit;
4533 }
4534 
4535 /* See uma.h */
4536 void
4537 uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini)
4538 {
4539 
4540 	ZONE_ASSERT_COLD(zone);
4541 	zone->uz_fini = zfini;
4542 }
4543 
4544 /* See uma.h */
4545 void
4546 uma_zone_set_freef(uma_zone_t zone, uma_free freef)
4547 {
4548 	uma_keg_t keg;
4549 
4550 	KEG_GET(zone, keg);
4551 	KEG_ASSERT_COLD(keg);
4552 	keg->uk_freef = freef;
4553 }
4554 
4555 /* See uma.h */
4556 void
4557 uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf)
4558 {
4559 	uma_keg_t keg;
4560 
4561 	KEG_GET(zone, keg);
4562 	KEG_ASSERT_COLD(keg);
4563 	keg->uk_allocf = allocf;
4564 }
4565 
4566 /* See uma.h */
4567 void
4568 uma_zone_set_smr(uma_zone_t zone, smr_t smr)
4569 {
4570 
4571 	ZONE_ASSERT_COLD(zone);
4572 
4573 	zone->uz_flags |= UMA_ZONE_SMR;
4574 	zone->uz_smr = smr;
4575 	zone_update_caches(zone);
4576 }
4577 
4578 smr_t
4579 uma_zone_get_smr(uma_zone_t zone)
4580 {
4581 
4582 	return (zone->uz_smr);
4583 }
4584 
4585 /* See uma.h */
4586 void
4587 uma_zone_reserve(uma_zone_t zone, int items)
4588 {
4589 	uma_keg_t keg;
4590 
4591 	KEG_GET(zone, keg);
4592 	KEG_ASSERT_COLD(keg);
4593 	keg->uk_reserve = items;
4594 }
4595 
4596 /* See uma.h */
4597 int
4598 uma_zone_reserve_kva(uma_zone_t zone, int count)
4599 {
4600 	uma_keg_t keg;
4601 	vm_offset_t kva;
4602 	u_int pages;
4603 
4604 	KEG_GET(zone, keg);
4605 	KEG_ASSERT_COLD(keg);
4606 	ZONE_ASSERT_COLD(zone);
4607 
4608 	pages = howmany(count, keg->uk_ipers) * keg->uk_ppera;
4609 
4610 #ifdef UMA_MD_SMALL_ALLOC
4611 	if (keg->uk_ppera > 1) {
4612 #else
4613 	if (1) {
4614 #endif
4615 		kva = kva_alloc((vm_size_t)pages * PAGE_SIZE);
4616 		if (kva == 0)
4617 			return (0);
4618 	} else
4619 		kva = 0;
4620 
4621 	ZONE_LOCK(zone);
4622 	MPASS(keg->uk_kva == 0);
4623 	keg->uk_kva = kva;
4624 	keg->uk_offset = 0;
4625 	zone->uz_max_items = pages * keg->uk_ipers;
4626 #ifdef UMA_MD_SMALL_ALLOC
4627 	keg->uk_allocf = (keg->uk_ppera > 1) ? noobj_alloc : uma_small_alloc;
4628 #else
4629 	keg->uk_allocf = noobj_alloc;
4630 #endif
4631 	keg->uk_flags |= UMA_ZFLAG_LIMIT | UMA_ZONE_NOFREE;
4632 	zone->uz_flags |= UMA_ZFLAG_LIMIT | UMA_ZONE_NOFREE;
4633 	zone_update_caches(zone);
4634 	ZONE_UNLOCK(zone);
4635 
4636 	return (1);
4637 }
4638 
4639 /* See uma.h */
4640 void
4641 uma_prealloc(uma_zone_t zone, int items)
4642 {
4643 	struct vm_domainset_iter di;
4644 	uma_domain_t dom;
4645 	uma_slab_t slab;
4646 	uma_keg_t keg;
4647 	int aflags, domain, slabs;
4648 
4649 	KEG_GET(zone, keg);
4650 	slabs = howmany(items, keg->uk_ipers);
4651 	while (slabs-- > 0) {
4652 		aflags = M_NOWAIT;
4653 		vm_domainset_iter_policy_ref_init(&di, &keg->uk_dr, &domain,
4654 		    &aflags);
4655 		for (;;) {
4656 			slab = keg_alloc_slab(keg, zone, domain, M_WAITOK,
4657 			    aflags);
4658 			if (slab != NULL) {
4659 				dom = &keg->uk_domain[slab->us_domain];
4660 				/*
4661 				 * keg_alloc_slab() always returns a slab on the
4662 				 * partial list.
4663 				 */
4664 				LIST_REMOVE(slab, us_link);
4665 				LIST_INSERT_HEAD(&dom->ud_free_slab, slab,
4666 				    us_link);
4667 				dom->ud_free_slabs++;
4668 				KEG_UNLOCK(keg, slab->us_domain);
4669 				break;
4670 			}
4671 			if (vm_domainset_iter_policy(&di, &domain) != 0)
4672 				vm_wait_doms(&keg->uk_dr.dr_policy->ds_mask);
4673 		}
4674 	}
4675 }
4676 
4677 /* See uma.h */
4678 void
4679 uma_reclaim(int req)
4680 {
4681 
4682 	CTR0(KTR_UMA, "UMA: vm asked us to release pages!");
4683 	sx_xlock(&uma_reclaim_lock);
4684 	bucket_enable();
4685 
4686 	switch (req) {
4687 	case UMA_RECLAIM_TRIM:
4688 		zone_foreach(zone_trim, NULL);
4689 		break;
4690 	case UMA_RECLAIM_DRAIN:
4691 	case UMA_RECLAIM_DRAIN_CPU:
4692 		zone_foreach(zone_drain, NULL);
4693 		if (req == UMA_RECLAIM_DRAIN_CPU) {
4694 			pcpu_cache_drain_safe(NULL);
4695 			zone_foreach(zone_drain, NULL);
4696 		}
4697 		break;
4698 	default:
4699 		panic("unhandled reclamation request %d", req);
4700 	}
4701 
4702 	/*
4703 	 * Some slabs may have been freed but this zone will be visited early
4704 	 * we visit again so that we can free pages that are empty once other
4705 	 * zones are drained.  We have to do the same for buckets.
4706 	 */
4707 	zone_drain(slabzones[0], NULL);
4708 	zone_drain(slabzones[1], NULL);
4709 	bucket_zone_drain();
4710 	sx_xunlock(&uma_reclaim_lock);
4711 }
4712 
4713 static volatile int uma_reclaim_needed;
4714 
4715 void
4716 uma_reclaim_wakeup(void)
4717 {
4718 
4719 	if (atomic_fetchadd_int(&uma_reclaim_needed, 1) == 0)
4720 		wakeup(uma_reclaim);
4721 }
4722 
4723 void
4724 uma_reclaim_worker(void *arg __unused)
4725 {
4726 
4727 	for (;;) {
4728 		sx_xlock(&uma_reclaim_lock);
4729 		while (atomic_load_int(&uma_reclaim_needed) == 0)
4730 			sx_sleep(uma_reclaim, &uma_reclaim_lock, PVM, "umarcl",
4731 			    hz);
4732 		sx_xunlock(&uma_reclaim_lock);
4733 		EVENTHANDLER_INVOKE(vm_lowmem, VM_LOW_KMEM);
4734 		uma_reclaim(UMA_RECLAIM_DRAIN_CPU);
4735 		atomic_store_int(&uma_reclaim_needed, 0);
4736 		/* Don't fire more than once per-second. */
4737 		pause("umarclslp", hz);
4738 	}
4739 }
4740 
4741 /* See uma.h */
4742 void
4743 uma_zone_reclaim(uma_zone_t zone, int req)
4744 {
4745 
4746 	switch (req) {
4747 	case UMA_RECLAIM_TRIM:
4748 		zone_trim(zone, NULL);
4749 		break;
4750 	case UMA_RECLAIM_DRAIN:
4751 		zone_drain(zone, NULL);
4752 		break;
4753 	case UMA_RECLAIM_DRAIN_CPU:
4754 		pcpu_cache_drain_safe(zone);
4755 		zone_drain(zone, NULL);
4756 		break;
4757 	default:
4758 		panic("unhandled reclamation request %d", req);
4759 	}
4760 }
4761 
4762 /* See uma.h */
4763 int
4764 uma_zone_exhausted(uma_zone_t zone)
4765 {
4766 
4767 	return (atomic_load_32(&zone->uz_sleepers) > 0);
4768 }
4769 
4770 unsigned long
4771 uma_limit(void)
4772 {
4773 
4774 	return (uma_kmem_limit);
4775 }
4776 
4777 void
4778 uma_set_limit(unsigned long limit)
4779 {
4780 
4781 	uma_kmem_limit = limit;
4782 }
4783 
4784 unsigned long
4785 uma_size(void)
4786 {
4787 
4788 	return (atomic_load_long(&uma_kmem_total));
4789 }
4790 
4791 long
4792 uma_avail(void)
4793 {
4794 
4795 	return (uma_kmem_limit - uma_size());
4796 }
4797 
4798 #ifdef DDB
4799 /*
4800  * Generate statistics across both the zone and its per-cpu cache's.  Return
4801  * desired statistics if the pointer is non-NULL for that statistic.
4802  *
4803  * Note: does not update the zone statistics, as it can't safely clear the
4804  * per-CPU cache statistic.
4805  *
4806  */
4807 static void
4808 uma_zone_sumstat(uma_zone_t z, long *cachefreep, uint64_t *allocsp,
4809     uint64_t *freesp, uint64_t *sleepsp, uint64_t *xdomainp)
4810 {
4811 	uma_cache_t cache;
4812 	uint64_t allocs, frees, sleeps, xdomain;
4813 	int cachefree, cpu;
4814 
4815 	allocs = frees = sleeps = xdomain = 0;
4816 	cachefree = 0;
4817 	CPU_FOREACH(cpu) {
4818 		cache = &z->uz_cpu[cpu];
4819 		cachefree += cache->uc_allocbucket.ucb_cnt;
4820 		cachefree += cache->uc_freebucket.ucb_cnt;
4821 		xdomain += cache->uc_crossbucket.ucb_cnt;
4822 		cachefree += cache->uc_crossbucket.ucb_cnt;
4823 		allocs += cache->uc_allocs;
4824 		frees += cache->uc_frees;
4825 	}
4826 	allocs += counter_u64_fetch(z->uz_allocs);
4827 	frees += counter_u64_fetch(z->uz_frees);
4828 	sleeps += z->uz_sleeps;
4829 	xdomain += z->uz_xdomain;
4830 	if (cachefreep != NULL)
4831 		*cachefreep = cachefree;
4832 	if (allocsp != NULL)
4833 		*allocsp = allocs;
4834 	if (freesp != NULL)
4835 		*freesp = frees;
4836 	if (sleepsp != NULL)
4837 		*sleepsp = sleeps;
4838 	if (xdomainp != NULL)
4839 		*xdomainp = xdomain;
4840 }
4841 #endif /* DDB */
4842 
4843 static int
4844 sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS)
4845 {
4846 	uma_keg_t kz;
4847 	uma_zone_t z;
4848 	int count;
4849 
4850 	count = 0;
4851 	rw_rlock(&uma_rwlock);
4852 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
4853 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
4854 			count++;
4855 	}
4856 	LIST_FOREACH(z, &uma_cachezones, uz_link)
4857 		count++;
4858 
4859 	rw_runlock(&uma_rwlock);
4860 	return (sysctl_handle_int(oidp, &count, 0, req));
4861 }
4862 
4863 static void
4864 uma_vm_zone_stats(struct uma_type_header *uth, uma_zone_t z, struct sbuf *sbuf,
4865     struct uma_percpu_stat *ups, bool internal)
4866 {
4867 	uma_zone_domain_t zdom;
4868 	uma_cache_t cache;
4869 	int i;
4870 
4871 
4872 	for (i = 0; i < vm_ndomains; i++) {
4873 		zdom = &z->uz_domain[i];
4874 		uth->uth_zone_free += zdom->uzd_nitems;
4875 	}
4876 	uth->uth_allocs = counter_u64_fetch(z->uz_allocs);
4877 	uth->uth_frees = counter_u64_fetch(z->uz_frees);
4878 	uth->uth_fails = counter_u64_fetch(z->uz_fails);
4879 	uth->uth_sleeps = z->uz_sleeps;
4880 	uth->uth_xdomain = z->uz_xdomain;
4881 
4882 	/*
4883 	 * While it is not normally safe to access the cache bucket pointers
4884 	 * while not on the CPU that owns the cache, we only allow the pointers
4885 	 * to be exchanged without the zone lock held, not invalidated, so
4886 	 * accept the possible race associated with bucket exchange during
4887 	 * monitoring.  Use atomic_load_ptr() to ensure that the bucket pointers
4888 	 * are loaded only once.
4889 	 */
4890 	for (i = 0; i < mp_maxid + 1; i++) {
4891 		bzero(&ups[i], sizeof(*ups));
4892 		if (internal || CPU_ABSENT(i))
4893 			continue;
4894 		cache = &z->uz_cpu[i];
4895 		ups[i].ups_cache_free += cache->uc_allocbucket.ucb_cnt;
4896 		ups[i].ups_cache_free += cache->uc_freebucket.ucb_cnt;
4897 		ups[i].ups_cache_free += cache->uc_crossbucket.ucb_cnt;
4898 		ups[i].ups_allocs = cache->uc_allocs;
4899 		ups[i].ups_frees = cache->uc_frees;
4900 	}
4901 }
4902 
4903 static int
4904 sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS)
4905 {
4906 	struct uma_stream_header ush;
4907 	struct uma_type_header uth;
4908 	struct uma_percpu_stat *ups;
4909 	struct sbuf sbuf;
4910 	uma_keg_t kz;
4911 	uma_zone_t z;
4912 	uint64_t items;
4913 	uint32_t kfree, pages;
4914 	int count, error, i;
4915 
4916 	error = sysctl_wire_old_buffer(req, 0);
4917 	if (error != 0)
4918 		return (error);
4919 	sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
4920 	sbuf_clear_flags(&sbuf, SBUF_INCLUDENUL);
4921 	ups = malloc((mp_maxid + 1) * sizeof(*ups), M_TEMP, M_WAITOK);
4922 
4923 	count = 0;
4924 	rw_rlock(&uma_rwlock);
4925 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
4926 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
4927 			count++;
4928 	}
4929 
4930 	LIST_FOREACH(z, &uma_cachezones, uz_link)
4931 		count++;
4932 
4933 	/*
4934 	 * Insert stream header.
4935 	 */
4936 	bzero(&ush, sizeof(ush));
4937 	ush.ush_version = UMA_STREAM_VERSION;
4938 	ush.ush_maxcpus = (mp_maxid + 1);
4939 	ush.ush_count = count;
4940 	(void)sbuf_bcat(&sbuf, &ush, sizeof(ush));
4941 
4942 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
4943 		kfree = pages = 0;
4944 		for (i = 0; i < vm_ndomains; i++) {
4945 			kfree += kz->uk_domain[i].ud_free_items;
4946 			pages += kz->uk_domain[i].ud_pages;
4947 		}
4948 		LIST_FOREACH(z, &kz->uk_zones, uz_link) {
4949 			bzero(&uth, sizeof(uth));
4950 			ZONE_LOCK(z);
4951 			strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
4952 			uth.uth_align = kz->uk_align;
4953 			uth.uth_size = kz->uk_size;
4954 			uth.uth_rsize = kz->uk_rsize;
4955 			if (z->uz_max_items > 0) {
4956 				items = UZ_ITEMS_COUNT(z->uz_items);
4957 				uth.uth_pages = (items / kz->uk_ipers) *
4958 					kz->uk_ppera;
4959 			} else
4960 				uth.uth_pages = pages;
4961 			uth.uth_maxpages = (z->uz_max_items / kz->uk_ipers) *
4962 			    kz->uk_ppera;
4963 			uth.uth_limit = z->uz_max_items;
4964 			uth.uth_keg_free = kfree;
4965 
4966 			/*
4967 			 * A zone is secondary is it is not the first entry
4968 			 * on the keg's zone list.
4969 			 */
4970 			if ((z->uz_flags & UMA_ZONE_SECONDARY) &&
4971 			    (LIST_FIRST(&kz->uk_zones) != z))
4972 				uth.uth_zone_flags = UTH_ZONE_SECONDARY;
4973 			uma_vm_zone_stats(&uth, z, &sbuf, ups,
4974 			    kz->uk_flags & UMA_ZFLAG_INTERNAL);
4975 			ZONE_UNLOCK(z);
4976 			(void)sbuf_bcat(&sbuf, &uth, sizeof(uth));
4977 			for (i = 0; i < mp_maxid + 1; i++)
4978 				(void)sbuf_bcat(&sbuf, &ups[i], sizeof(ups[i]));
4979 		}
4980 	}
4981 	LIST_FOREACH(z, &uma_cachezones, uz_link) {
4982 		bzero(&uth, sizeof(uth));
4983 		ZONE_LOCK(z);
4984 		strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
4985 		uth.uth_size = z->uz_size;
4986 		uma_vm_zone_stats(&uth, z, &sbuf, ups, false);
4987 		ZONE_UNLOCK(z);
4988 		(void)sbuf_bcat(&sbuf, &uth, sizeof(uth));
4989 		for (i = 0; i < mp_maxid + 1; i++)
4990 			(void)sbuf_bcat(&sbuf, &ups[i], sizeof(ups[i]));
4991 	}
4992 
4993 	rw_runlock(&uma_rwlock);
4994 	error = sbuf_finish(&sbuf);
4995 	sbuf_delete(&sbuf);
4996 	free(ups, M_TEMP);
4997 	return (error);
4998 }
4999 
5000 int
5001 sysctl_handle_uma_zone_max(SYSCTL_HANDLER_ARGS)
5002 {
5003 	uma_zone_t zone = *(uma_zone_t *)arg1;
5004 	int error, max;
5005 
5006 	max = uma_zone_get_max(zone);
5007 	error = sysctl_handle_int(oidp, &max, 0, req);
5008 	if (error || !req->newptr)
5009 		return (error);
5010 
5011 	uma_zone_set_max(zone, max);
5012 
5013 	return (0);
5014 }
5015 
5016 int
5017 sysctl_handle_uma_zone_cur(SYSCTL_HANDLER_ARGS)
5018 {
5019 	uma_zone_t zone;
5020 	int cur;
5021 
5022 	/*
5023 	 * Some callers want to add sysctls for global zones that
5024 	 * may not yet exist so they pass a pointer to a pointer.
5025 	 */
5026 	if (arg2 == 0)
5027 		zone = *(uma_zone_t *)arg1;
5028 	else
5029 		zone = arg1;
5030 	cur = uma_zone_get_cur(zone);
5031 	return (sysctl_handle_int(oidp, &cur, 0, req));
5032 }
5033 
5034 static int
5035 sysctl_handle_uma_zone_allocs(SYSCTL_HANDLER_ARGS)
5036 {
5037 	uma_zone_t zone = arg1;
5038 	uint64_t cur;
5039 
5040 	cur = uma_zone_get_allocs(zone);
5041 	return (sysctl_handle_64(oidp, &cur, 0, req));
5042 }
5043 
5044 static int
5045 sysctl_handle_uma_zone_frees(SYSCTL_HANDLER_ARGS)
5046 {
5047 	uma_zone_t zone = arg1;
5048 	uint64_t cur;
5049 
5050 	cur = uma_zone_get_frees(zone);
5051 	return (sysctl_handle_64(oidp, &cur, 0, req));
5052 }
5053 
5054 static int
5055 sysctl_handle_uma_zone_flags(SYSCTL_HANDLER_ARGS)
5056 {
5057 	struct sbuf sbuf;
5058 	uma_zone_t zone = arg1;
5059 	int error;
5060 
5061 	sbuf_new_for_sysctl(&sbuf, NULL, 0, req);
5062 	if (zone->uz_flags != 0)
5063 		sbuf_printf(&sbuf, "0x%b", zone->uz_flags, PRINT_UMA_ZFLAGS);
5064 	else
5065 		sbuf_printf(&sbuf, "0");
5066 	error = sbuf_finish(&sbuf);
5067 	sbuf_delete(&sbuf);
5068 
5069 	return (error);
5070 }
5071 
5072 static int
5073 sysctl_handle_uma_slab_efficiency(SYSCTL_HANDLER_ARGS)
5074 {
5075 	uma_keg_t keg = arg1;
5076 	int avail, effpct, total;
5077 
5078 	total = keg->uk_ppera * PAGE_SIZE;
5079 	if ((keg->uk_flags & UMA_ZFLAG_OFFPAGE) != 0)
5080 		total += slabzone(keg->uk_ipers)->uz_keg->uk_rsize;
5081 	/*
5082 	 * We consider the client's requested size and alignment here, not the
5083 	 * real size determination uk_rsize, because we also adjust the real
5084 	 * size for internal implementation reasons (max bitset size).
5085 	 */
5086 	avail = keg->uk_ipers * roundup2(keg->uk_size, keg->uk_align + 1);
5087 	if ((keg->uk_flags & UMA_ZONE_PCPU) != 0)
5088 		avail *= mp_maxid + 1;
5089 	effpct = 100 * avail / total;
5090 	return (sysctl_handle_int(oidp, &effpct, 0, req));
5091 }
5092 
5093 static int
5094 sysctl_handle_uma_zone_items(SYSCTL_HANDLER_ARGS)
5095 {
5096 	uma_zone_t zone = arg1;
5097 	uint64_t cur;
5098 
5099 	cur = UZ_ITEMS_COUNT(atomic_load_64(&zone->uz_items));
5100 	return (sysctl_handle_64(oidp, &cur, 0, req));
5101 }
5102 
5103 #ifdef INVARIANTS
5104 static uma_slab_t
5105 uma_dbg_getslab(uma_zone_t zone, void *item)
5106 {
5107 	uma_slab_t slab;
5108 	uma_keg_t keg;
5109 	uint8_t *mem;
5110 
5111 	/*
5112 	 * It is safe to return the slab here even though the
5113 	 * zone is unlocked because the item's allocation state
5114 	 * essentially holds a reference.
5115 	 */
5116 	mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
5117 	if ((zone->uz_flags & UMA_ZFLAG_CACHE) != 0)
5118 		return (NULL);
5119 	if (zone->uz_flags & UMA_ZFLAG_VTOSLAB)
5120 		return (vtoslab((vm_offset_t)mem));
5121 	keg = zone->uz_keg;
5122 	if ((keg->uk_flags & UMA_ZFLAG_HASH) == 0)
5123 		return ((uma_slab_t)(mem + keg->uk_pgoff));
5124 	KEG_LOCK(keg, 0);
5125 	slab = hash_sfind(&keg->uk_hash, mem);
5126 	KEG_UNLOCK(keg, 0);
5127 
5128 	return (slab);
5129 }
5130 
5131 static bool
5132 uma_dbg_zskip(uma_zone_t zone, void *mem)
5133 {
5134 
5135 	if ((zone->uz_flags & UMA_ZFLAG_CACHE) != 0)
5136 		return (true);
5137 
5138 	return (uma_dbg_kskip(zone->uz_keg, mem));
5139 }
5140 
5141 static bool
5142 uma_dbg_kskip(uma_keg_t keg, void *mem)
5143 {
5144 	uintptr_t idx;
5145 
5146 	if (dbg_divisor == 0)
5147 		return (true);
5148 
5149 	if (dbg_divisor == 1)
5150 		return (false);
5151 
5152 	idx = (uintptr_t)mem >> PAGE_SHIFT;
5153 	if (keg->uk_ipers > 1) {
5154 		idx *= keg->uk_ipers;
5155 		idx += ((uintptr_t)mem & PAGE_MASK) / keg->uk_rsize;
5156 	}
5157 
5158 	if ((idx / dbg_divisor) * dbg_divisor != idx) {
5159 		counter_u64_add(uma_skip_cnt, 1);
5160 		return (true);
5161 	}
5162 	counter_u64_add(uma_dbg_cnt, 1);
5163 
5164 	return (false);
5165 }
5166 
5167 /*
5168  * Set up the slab's freei data such that uma_dbg_free can function.
5169  *
5170  */
5171 static void
5172 uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item)
5173 {
5174 	uma_keg_t keg;
5175 	int freei;
5176 
5177 	if (slab == NULL) {
5178 		slab = uma_dbg_getslab(zone, item);
5179 		if (slab == NULL)
5180 			panic("uma: item %p did not belong to zone %s\n",
5181 			    item, zone->uz_name);
5182 	}
5183 	keg = zone->uz_keg;
5184 	freei = slab_item_index(slab, keg, item);
5185 
5186 	if (BIT_ISSET(keg->uk_ipers, freei, slab_dbg_bits(slab, keg)))
5187 		panic("Duplicate alloc of %p from zone %p(%s) slab %p(%d)\n",
5188 		    item, zone, zone->uz_name, slab, freei);
5189 	BIT_SET_ATOMIC(keg->uk_ipers, freei, slab_dbg_bits(slab, keg));
5190 }
5191 
5192 /*
5193  * Verifies freed addresses.  Checks for alignment, valid slab membership
5194  * and duplicate frees.
5195  *
5196  */
5197 static void
5198 uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item)
5199 {
5200 	uma_keg_t keg;
5201 	int freei;
5202 
5203 	if (slab == NULL) {
5204 		slab = uma_dbg_getslab(zone, item);
5205 		if (slab == NULL)
5206 			panic("uma: Freed item %p did not belong to zone %s\n",
5207 			    item, zone->uz_name);
5208 	}
5209 	keg = zone->uz_keg;
5210 	freei = slab_item_index(slab, keg, item);
5211 
5212 	if (freei >= keg->uk_ipers)
5213 		panic("Invalid free of %p from zone %p(%s) slab %p(%d)\n",
5214 		    item, zone, zone->uz_name, slab, freei);
5215 
5216 	if (slab_item(slab, keg, freei) != item)
5217 		panic("Unaligned free of %p from zone %p(%s) slab %p(%d)\n",
5218 		    item, zone, zone->uz_name, slab, freei);
5219 
5220 	if (!BIT_ISSET(keg->uk_ipers, freei, slab_dbg_bits(slab, keg)))
5221 		panic("Duplicate free of %p from zone %p(%s) slab %p(%d)\n",
5222 		    item, zone, zone->uz_name, slab, freei);
5223 
5224 	BIT_CLR_ATOMIC(keg->uk_ipers, freei, slab_dbg_bits(slab, keg));
5225 }
5226 #endif /* INVARIANTS */
5227 
5228 #ifdef DDB
5229 static int64_t
5230 get_uma_stats(uma_keg_t kz, uma_zone_t z, uint64_t *allocs, uint64_t *used,
5231     uint64_t *sleeps, long *cachefree, uint64_t *xdomain)
5232 {
5233 	uint64_t frees;
5234 	int i;
5235 
5236 	if (kz->uk_flags & UMA_ZFLAG_INTERNAL) {
5237 		*allocs = counter_u64_fetch(z->uz_allocs);
5238 		frees = counter_u64_fetch(z->uz_frees);
5239 		*sleeps = z->uz_sleeps;
5240 		*cachefree = 0;
5241 		*xdomain = 0;
5242 	} else
5243 		uma_zone_sumstat(z, cachefree, allocs, &frees, sleeps,
5244 		    xdomain);
5245 	for (i = 0; i < vm_ndomains; i++) {
5246 		*cachefree += z->uz_domain[i].uzd_nitems;
5247 		if (!((z->uz_flags & UMA_ZONE_SECONDARY) &&
5248 		    (LIST_FIRST(&kz->uk_zones) != z)))
5249 			*cachefree += kz->uk_domain[i].ud_free_items;
5250 	}
5251 	*used = *allocs - frees;
5252 	return (((int64_t)*used + *cachefree) * kz->uk_size);
5253 }
5254 
5255 DB_SHOW_COMMAND(uma, db_show_uma)
5256 {
5257 	const char *fmt_hdr, *fmt_entry;
5258 	uma_keg_t kz;
5259 	uma_zone_t z;
5260 	uint64_t allocs, used, sleeps, xdomain;
5261 	long cachefree;
5262 	/* variables for sorting */
5263 	uma_keg_t cur_keg;
5264 	uma_zone_t cur_zone, last_zone;
5265 	int64_t cur_size, last_size, size;
5266 	int ties;
5267 
5268 	/* /i option produces machine-parseable CSV output */
5269 	if (modif[0] == 'i') {
5270 		fmt_hdr = "%s,%s,%s,%s,%s,%s,%s,%s,%s\n";
5271 		fmt_entry = "\"%s\",%ju,%jd,%ld,%ju,%ju,%u,%jd,%ju\n";
5272 	} else {
5273 		fmt_hdr = "%18s %6s %7s %7s %11s %7s %7s %10s %8s\n";
5274 		fmt_entry = "%18s %6ju %7jd %7ld %11ju %7ju %7u %10jd %8ju\n";
5275 	}
5276 
5277 	db_printf(fmt_hdr, "Zone", "Size", "Used", "Free", "Requests",
5278 	    "Sleeps", "Bucket", "Total Mem", "XFree");
5279 
5280 	/* Sort the zones with largest size first. */
5281 	last_zone = NULL;
5282 	last_size = INT64_MAX;
5283 	for (;;) {
5284 		cur_zone = NULL;
5285 		cur_size = -1;
5286 		ties = 0;
5287 		LIST_FOREACH(kz, &uma_kegs, uk_link) {
5288 			LIST_FOREACH(z, &kz->uk_zones, uz_link) {
5289 				/*
5290 				 * In the case of size ties, print out zones
5291 				 * in the order they are encountered.  That is,
5292 				 * when we encounter the most recently output
5293 				 * zone, we have already printed all preceding
5294 				 * ties, and we must print all following ties.
5295 				 */
5296 				if (z == last_zone) {
5297 					ties = 1;
5298 					continue;
5299 				}
5300 				size = get_uma_stats(kz, z, &allocs, &used,
5301 				    &sleeps, &cachefree, &xdomain);
5302 				if (size > cur_size && size < last_size + ties)
5303 				{
5304 					cur_size = size;
5305 					cur_zone = z;
5306 					cur_keg = kz;
5307 				}
5308 			}
5309 		}
5310 		if (cur_zone == NULL)
5311 			break;
5312 
5313 		size = get_uma_stats(cur_keg, cur_zone, &allocs, &used,
5314 		    &sleeps, &cachefree, &xdomain);
5315 		db_printf(fmt_entry, cur_zone->uz_name,
5316 		    (uintmax_t)cur_keg->uk_size, (intmax_t)used, cachefree,
5317 		    (uintmax_t)allocs, (uintmax_t)sleeps,
5318 		    (unsigned)cur_zone->uz_bucket_size, (intmax_t)size,
5319 		    xdomain);
5320 
5321 		if (db_pager_quit)
5322 			return;
5323 		last_zone = cur_zone;
5324 		last_size = cur_size;
5325 	}
5326 }
5327 
5328 DB_SHOW_COMMAND(umacache, db_show_umacache)
5329 {
5330 	uma_zone_t z;
5331 	uint64_t allocs, frees;
5332 	long cachefree;
5333 	int i;
5334 
5335 	db_printf("%18s %8s %8s %8s %12s %8s\n", "Zone", "Size", "Used", "Free",
5336 	    "Requests", "Bucket");
5337 	LIST_FOREACH(z, &uma_cachezones, uz_link) {
5338 		uma_zone_sumstat(z, &cachefree, &allocs, &frees, NULL, NULL);
5339 		for (i = 0; i < vm_ndomains; i++)
5340 			cachefree += z->uz_domain[i].uzd_nitems;
5341 		db_printf("%18s %8ju %8jd %8ld %12ju %8u\n",
5342 		    z->uz_name, (uintmax_t)z->uz_size,
5343 		    (intmax_t)(allocs - frees), cachefree,
5344 		    (uintmax_t)allocs, z->uz_bucket_size);
5345 		if (db_pager_quit)
5346 			return;
5347 	}
5348 }
5349 #endif	/* DDB */
5350