xref: /freebsd/sys/vm/uma_core.c (revision 1db64f89363c97858961c4df0b7d02f3223723cf)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 #include "opt_ddb.h"
54 #include "opt_param.h"
55 #include "opt_vm.h"
56 
57 #include <sys/param.h>
58 #include <sys/systm.h>
59 #include <sys/asan.h>
60 #include <sys/bitset.h>
61 #include <sys/domainset.h>
62 #include <sys/eventhandler.h>
63 #include <sys/kernel.h>
64 #include <sys/types.h>
65 #include <sys/limits.h>
66 #include <sys/queue.h>
67 #include <sys/malloc.h>
68 #include <sys/ktr.h>
69 #include <sys/lock.h>
70 #include <sys/msan.h>
71 #include <sys/mutex.h>
72 #include <sys/proc.h>
73 #include <sys/random.h>
74 #include <sys/rwlock.h>
75 #include <sys/sbuf.h>
76 #include <sys/sched.h>
77 #include <sys/sleepqueue.h>
78 #include <sys/smp.h>
79 #include <sys/smr.h>
80 #include <sys/sysctl.h>
81 #include <sys/taskqueue.h>
82 #include <sys/vmmeter.h>
83 
84 #include <vm/vm.h>
85 #include <vm/vm_param.h>
86 #include <vm/vm_domainset.h>
87 #include <vm/vm_object.h>
88 #include <vm/vm_page.h>
89 #include <vm/vm_pageout.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/vm_dumpset.h>
96 #include <vm/uma.h>
97 #include <vm/uma_int.h>
98 #include <vm/uma_dbg.h>
99 
100 #include <ddb/ddb.h>
101 
102 #ifdef DEBUG_MEMGUARD
103 #include <vm/memguard.h>
104 #endif
105 
106 #include <machine/md_var.h>
107 
108 #ifdef INVARIANTS
109 #define	UMA_ALWAYS_CTORDTOR	1
110 #else
111 #define	UMA_ALWAYS_CTORDTOR	0
112 #endif
113 
114 /*
115  * This is the zone and keg from which all zones are spawned.
116  */
117 static uma_zone_t kegs;
118 static uma_zone_t zones;
119 
120 /*
121  * On INVARIANTS builds, the slab contains a second bitset of the same size,
122  * "dbg_bits", which is laid out immediately after us_free.
123  */
124 #ifdef INVARIANTS
125 #define	SLAB_BITSETS	2
126 #else
127 #define	SLAB_BITSETS	1
128 #endif
129 
130 /*
131  * These are the two zones from which all offpage uma_slab_ts are allocated.
132  *
133  * One zone is for slab headers that can represent a larger number of items,
134  * making the slabs themselves more efficient, and the other zone is for
135  * headers that are smaller and represent fewer items, making the headers more
136  * efficient.
137  */
138 #define	SLABZONE_SIZE(setsize)					\
139     (sizeof(struct uma_hash_slab) + BITSET_SIZE(setsize) * SLAB_BITSETS)
140 #define	SLABZONE0_SETSIZE	(PAGE_SIZE / 16)
141 #define	SLABZONE1_SETSIZE	SLAB_MAX_SETSIZE
142 #define	SLABZONE0_SIZE	SLABZONE_SIZE(SLABZONE0_SETSIZE)
143 #define	SLABZONE1_SIZE	SLABZONE_SIZE(SLABZONE1_SETSIZE)
144 static uma_zone_t slabzones[2];
145 
146 /*
147  * The initial hash tables come out of this zone so they can be allocated
148  * prior to malloc coming up.
149  */
150 static uma_zone_t hashzone;
151 
152 /* The boot-time adjusted value for cache line alignment. */
153 static unsigned int uma_cache_align_mask = 64 - 1;
154 
155 static MALLOC_DEFINE(M_UMAHASH, "UMAHash", "UMA Hash Buckets");
156 static MALLOC_DEFINE(M_UMA, "UMA", "UMA Misc");
157 
158 /*
159  * Are we allowed to allocate buckets?
160  */
161 static int bucketdisable = 1;
162 
163 /* Linked list of all kegs in the system */
164 static LIST_HEAD(,uma_keg) uma_kegs = LIST_HEAD_INITIALIZER(uma_kegs);
165 
166 /* Linked list of all cache-only zones in the system */
167 static LIST_HEAD(,uma_zone) uma_cachezones =
168     LIST_HEAD_INITIALIZER(uma_cachezones);
169 
170 /*
171  * Mutex for global lists: uma_kegs, uma_cachezones, and the per-keg list of
172  * zones.
173  */
174 static struct rwlock_padalign __exclusive_cache_line uma_rwlock;
175 
176 static struct sx uma_reclaim_lock;
177 
178 /*
179  * First available virual address for boot time allocations.
180  */
181 static vm_offset_t bootstart;
182 static vm_offset_t bootmem;
183 
184 /*
185  * kmem soft limit, initialized by uma_set_limit().  Ensure that early
186  * allocations don't trigger a wakeup of the reclaim thread.
187  */
188 unsigned long uma_kmem_limit = LONG_MAX;
189 SYSCTL_ULONG(_vm, OID_AUTO, uma_kmem_limit, CTLFLAG_RD, &uma_kmem_limit, 0,
190     "UMA kernel memory soft limit");
191 unsigned long uma_kmem_total;
192 SYSCTL_ULONG(_vm, OID_AUTO, uma_kmem_total, CTLFLAG_RD, &uma_kmem_total, 0,
193     "UMA kernel memory usage");
194 
195 /* Is the VM done starting up? */
196 static enum {
197 	BOOT_COLD,
198 	BOOT_KVA,
199 	BOOT_PCPU,
200 	BOOT_RUNNING,
201 	BOOT_SHUTDOWN,
202 } booted = BOOT_COLD;
203 
204 /*
205  * This is the handle used to schedule events that need to happen
206  * outside of the allocation fast path.
207  */
208 static struct timeout_task uma_timeout_task;
209 #define	UMA_TIMEOUT	20		/* Seconds for callout interval. */
210 
211 /*
212  * This structure is passed as the zone ctor arg so that I don't have to create
213  * a special allocation function just for zones.
214  */
215 struct uma_zctor_args {
216 	const char *name;
217 	size_t size;
218 	uma_ctor ctor;
219 	uma_dtor dtor;
220 	uma_init uminit;
221 	uma_fini fini;
222 	uma_import import;
223 	uma_release release;
224 	void *arg;
225 	uma_keg_t keg;
226 	int align;
227 	uint32_t flags;
228 };
229 
230 struct uma_kctor_args {
231 	uma_zone_t zone;
232 	size_t size;
233 	uma_init uminit;
234 	uma_fini fini;
235 	int align;
236 	uint32_t flags;
237 };
238 
239 struct uma_bucket_zone {
240 	uma_zone_t	ubz_zone;
241 	const char	*ubz_name;
242 	int		ubz_entries;	/* Number of items it can hold. */
243 	int		ubz_maxsize;	/* Maximum allocation size per-item. */
244 };
245 
246 /*
247  * Compute the actual number of bucket entries to pack them in power
248  * of two sizes for more efficient space utilization.
249  */
250 #define	BUCKET_SIZE(n)						\
251     (((sizeof(void *) * (n)) - sizeof(struct uma_bucket)) / sizeof(void *))
252 
253 #define	BUCKET_MAX	BUCKET_SIZE(256)
254 
255 struct uma_bucket_zone bucket_zones[] = {
256 	/* Literal bucket sizes. */
257 	{ NULL, "2 Bucket", 2, 4096 },
258 	{ NULL, "4 Bucket", 4, 3072 },
259 	{ NULL, "8 Bucket", 8, 2048 },
260 	{ NULL, "16 Bucket", 16, 1024 },
261 	/* Rounded down power of 2 sizes for efficiency. */
262 	{ NULL, "32 Bucket", BUCKET_SIZE(32), 512 },
263 	{ NULL, "64 Bucket", BUCKET_SIZE(64), 256 },
264 	{ NULL, "128 Bucket", BUCKET_SIZE(128), 128 },
265 	{ NULL, "256 Bucket", BUCKET_SIZE(256), 64 },
266 	{ NULL, NULL, 0}
267 };
268 
269 /*
270  * Flags and enumerations to be passed to internal functions.
271  */
272 enum zfreeskip {
273 	SKIP_NONE =	0,
274 	SKIP_CNT =	0x00000001,
275 	SKIP_DTOR =	0x00010000,
276 	SKIP_FINI =	0x00020000,
277 };
278 
279 /* Prototypes.. */
280 
281 void	uma_startup1(vm_offset_t);
282 void	uma_startup2(void);
283 
284 static void *noobj_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
285 static void *page_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
286 static void *pcpu_page_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
287 static void *startup_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
288 static void *contig_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
289 static void page_free(void *, vm_size_t, uint8_t);
290 static void pcpu_page_free(void *, vm_size_t, uint8_t);
291 static uma_slab_t keg_alloc_slab(uma_keg_t, uma_zone_t, int, int, int);
292 static void cache_drain(uma_zone_t);
293 static void bucket_drain(uma_zone_t, uma_bucket_t);
294 static void bucket_cache_reclaim(uma_zone_t zone, bool, int);
295 static bool bucket_cache_reclaim_domain(uma_zone_t, bool, bool, int);
296 static int keg_ctor(void *, int, void *, int);
297 static void keg_dtor(void *, int, void *);
298 static void keg_drain(uma_keg_t keg, int domain);
299 static int zone_ctor(void *, int, void *, int);
300 static void zone_dtor(void *, int, void *);
301 static inline void item_dtor(uma_zone_t zone, void *item, int size,
302     void *udata, enum zfreeskip skip);
303 static int zero_init(void *, int, int);
304 static void zone_free_bucket(uma_zone_t zone, uma_bucket_t bucket, void *udata,
305     int itemdomain, bool ws);
306 static void zone_foreach(void (*zfunc)(uma_zone_t, void *), void *);
307 static void zone_foreach_unlocked(void (*zfunc)(uma_zone_t, void *), void *);
308 static void zone_timeout(uma_zone_t zone, void *);
309 static int hash_alloc(struct uma_hash *, u_int);
310 static int hash_expand(struct uma_hash *, struct uma_hash *);
311 static void hash_free(struct uma_hash *hash);
312 static void uma_timeout(void *, int);
313 static void uma_shutdown(void);
314 static void *zone_alloc_item(uma_zone_t, void *, int, int);
315 static void zone_free_item(uma_zone_t, void *, void *, enum zfreeskip);
316 static int zone_alloc_limit(uma_zone_t zone, int count, int flags);
317 static void zone_free_limit(uma_zone_t zone, int count);
318 static void bucket_enable(void);
319 static void bucket_init(void);
320 static uma_bucket_t bucket_alloc(uma_zone_t zone, void *, int);
321 static void bucket_free(uma_zone_t zone, uma_bucket_t, void *);
322 static void bucket_zone_drain(int domain);
323 static uma_bucket_t zone_alloc_bucket(uma_zone_t, void *, int, int);
324 static void *slab_alloc_item(uma_keg_t keg, uma_slab_t slab);
325 static void slab_free_item(uma_zone_t zone, uma_slab_t slab, void *item);
326 static size_t slab_sizeof(int nitems);
327 static uma_keg_t uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit,
328     uma_fini fini, int align, uint32_t flags);
329 static int zone_import(void *, void **, int, int, int);
330 static void zone_release(void *, void **, int);
331 static bool cache_alloc(uma_zone_t, uma_cache_t, void *, int);
332 static bool cache_free(uma_zone_t, uma_cache_t, void *, int);
333 
334 static int sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS);
335 static int sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS);
336 static int sysctl_handle_uma_zone_allocs(SYSCTL_HANDLER_ARGS);
337 static int sysctl_handle_uma_zone_frees(SYSCTL_HANDLER_ARGS);
338 static int sysctl_handle_uma_zone_flags(SYSCTL_HANDLER_ARGS);
339 static int sysctl_handle_uma_slab_efficiency(SYSCTL_HANDLER_ARGS);
340 static int sysctl_handle_uma_zone_items(SYSCTL_HANDLER_ARGS);
341 
342 static uint64_t uma_zone_get_allocs(uma_zone_t zone);
343 
344 static SYSCTL_NODE(_vm, OID_AUTO, debug, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
345     "Memory allocation debugging");
346 
347 #ifdef INVARIANTS
348 static uint64_t uma_keg_get_allocs(uma_keg_t zone);
349 static inline struct noslabbits *slab_dbg_bits(uma_slab_t slab, uma_keg_t keg);
350 
351 static bool uma_dbg_kskip(uma_keg_t keg, void *mem);
352 static bool uma_dbg_zskip(uma_zone_t zone, void *mem);
353 static void uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item);
354 static void uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item);
355 
356 static u_int dbg_divisor = 1;
357 SYSCTL_UINT(_vm_debug, OID_AUTO, divisor,
358     CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &dbg_divisor, 0,
359     "Debug & thrash every this item in memory allocator");
360 
361 static counter_u64_t uma_dbg_cnt = EARLY_COUNTER;
362 static counter_u64_t uma_skip_cnt = EARLY_COUNTER;
363 SYSCTL_COUNTER_U64(_vm_debug, OID_AUTO, trashed, CTLFLAG_RD,
364     &uma_dbg_cnt, "memory items debugged");
365 SYSCTL_COUNTER_U64(_vm_debug, OID_AUTO, skipped, CTLFLAG_RD,
366     &uma_skip_cnt, "memory items skipped, not debugged");
367 #endif
368 
369 SYSCTL_NODE(_vm, OID_AUTO, uma, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
370     "Universal Memory Allocator");
371 
372 SYSCTL_PROC(_vm, OID_AUTO, zone_count, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLTYPE_INT,
373     0, 0, sysctl_vm_zone_count, "I", "Number of UMA zones");
374 
375 SYSCTL_PROC(_vm, OID_AUTO, zone_stats, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLTYPE_STRUCT,
376     0, 0, sysctl_vm_zone_stats, "s,struct uma_type_header", "Zone Stats");
377 
378 static int zone_warnings = 1;
379 SYSCTL_INT(_vm, OID_AUTO, zone_warnings, CTLFLAG_RWTUN, &zone_warnings, 0,
380     "Warn when UMA zones becomes full");
381 
382 static int multipage_slabs = 1;
383 TUNABLE_INT("vm.debug.uma_multipage_slabs", &multipage_slabs);
384 SYSCTL_INT(_vm_debug, OID_AUTO, uma_multipage_slabs,
385     CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &multipage_slabs, 0,
386     "UMA may choose larger slab sizes for better efficiency");
387 
388 /*
389  * Select the slab zone for an offpage slab with the given maximum item count.
390  */
391 static inline uma_zone_t
392 slabzone(int ipers)
393 {
394 
395 	return (slabzones[ipers > SLABZONE0_SETSIZE]);
396 }
397 
398 /*
399  * This routine checks to see whether or not it's safe to enable buckets.
400  */
401 static void
402 bucket_enable(void)
403 {
404 
405 	KASSERT(booted >= BOOT_KVA, ("Bucket enable before init"));
406 	bucketdisable = vm_page_count_min();
407 }
408 
409 /*
410  * Initialize bucket_zones, the array of zones of buckets of various sizes.
411  *
412  * For each zone, calculate the memory required for each bucket, consisting
413  * of the header and an array of pointers.
414  */
415 static void
416 bucket_init(void)
417 {
418 	struct uma_bucket_zone *ubz;
419 	int size;
420 
421 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++) {
422 		size = roundup(sizeof(struct uma_bucket), sizeof(void *));
423 		size += sizeof(void *) * ubz->ubz_entries;
424 		ubz->ubz_zone = uma_zcreate(ubz->ubz_name, size,
425 		    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR,
426 		    UMA_ZONE_MTXCLASS | UMA_ZFLAG_BUCKET |
427 		    UMA_ZONE_FIRSTTOUCH);
428 	}
429 }
430 
431 /*
432  * Given a desired number of entries for a bucket, return the zone from which
433  * to allocate the bucket.
434  */
435 static struct uma_bucket_zone *
436 bucket_zone_lookup(int entries)
437 {
438 	struct uma_bucket_zone *ubz;
439 
440 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
441 		if (ubz->ubz_entries >= entries)
442 			return (ubz);
443 	ubz--;
444 	return (ubz);
445 }
446 
447 static int
448 bucket_select(int size)
449 {
450 	struct uma_bucket_zone *ubz;
451 
452 	ubz = &bucket_zones[0];
453 	if (size > ubz->ubz_maxsize)
454 		return MAX((ubz->ubz_maxsize * ubz->ubz_entries) / size, 1);
455 
456 	for (; ubz->ubz_entries != 0; ubz++)
457 		if (ubz->ubz_maxsize < size)
458 			break;
459 	ubz--;
460 	return (ubz->ubz_entries);
461 }
462 
463 static uma_bucket_t
464 bucket_alloc(uma_zone_t zone, void *udata, int flags)
465 {
466 	struct uma_bucket_zone *ubz;
467 	uma_bucket_t bucket;
468 
469 	/*
470 	 * Don't allocate buckets early in boot.
471 	 */
472 	if (__predict_false(booted < BOOT_KVA))
473 		return (NULL);
474 
475 	/*
476 	 * To limit bucket recursion we store the original zone flags
477 	 * in a cookie passed via zalloc_arg/zfree_arg.  This allows the
478 	 * NOVM flag to persist even through deep recursions.  We also
479 	 * store ZFLAG_BUCKET once we have recursed attempting to allocate
480 	 * a bucket for a bucket zone so we do not allow infinite bucket
481 	 * recursion.  This cookie will even persist to frees of unused
482 	 * buckets via the allocation path or bucket allocations in the
483 	 * free path.
484 	 */
485 	if ((zone->uz_flags & UMA_ZFLAG_BUCKET) == 0)
486 		udata = (void *)(uintptr_t)zone->uz_flags;
487 	else {
488 		if ((uintptr_t)udata & UMA_ZFLAG_BUCKET)
489 			return (NULL);
490 		udata = (void *)((uintptr_t)udata | UMA_ZFLAG_BUCKET);
491 	}
492 	if (((uintptr_t)udata & UMA_ZONE_VM) != 0)
493 		flags |= M_NOVM;
494 	ubz = bucket_zone_lookup(atomic_load_16(&zone->uz_bucket_size));
495 	if (ubz->ubz_zone == zone && (ubz + 1)->ubz_entries != 0)
496 		ubz++;
497 	bucket = uma_zalloc_arg(ubz->ubz_zone, udata, flags);
498 	if (bucket) {
499 #ifdef INVARIANTS
500 		bzero(bucket->ub_bucket, sizeof(void *) * ubz->ubz_entries);
501 #endif
502 		bucket->ub_cnt = 0;
503 		bucket->ub_entries = min(ubz->ubz_entries,
504 		    zone->uz_bucket_size_max);
505 		bucket->ub_seq = SMR_SEQ_INVALID;
506 		CTR3(KTR_UMA, "bucket_alloc: zone %s(%p) allocated bucket %p",
507 		    zone->uz_name, zone, bucket);
508 	}
509 
510 	return (bucket);
511 }
512 
513 static void
514 bucket_free(uma_zone_t zone, uma_bucket_t bucket, void *udata)
515 {
516 	struct uma_bucket_zone *ubz;
517 
518 	if (bucket->ub_cnt != 0)
519 		bucket_drain(zone, bucket);
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(int domain)
533 {
534 	struct uma_bucket_zone *ubz;
535 
536 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
537 		uma_zone_reclaim_domain(ubz->ubz_zone, UMA_RECLAIM_DRAIN,
538 		    domain);
539 }
540 
541 #ifdef KASAN
542 _Static_assert(UMA_SMALLEST_UNIT % KASAN_SHADOW_SCALE == 0,
543     "Base UMA allocation size not a multiple of the KASAN scale factor");
544 
545 static void
546 kasan_mark_item_valid(uma_zone_t zone, void *item)
547 {
548 	void *pcpu_item;
549 	size_t sz, rsz;
550 	int i;
551 
552 	if ((zone->uz_flags & UMA_ZONE_NOKASAN) != 0)
553 		return;
554 
555 	sz = zone->uz_size;
556 	rsz = roundup2(sz, KASAN_SHADOW_SCALE);
557 	if ((zone->uz_flags & UMA_ZONE_PCPU) == 0) {
558 		kasan_mark(item, sz, rsz, KASAN_GENERIC_REDZONE);
559 	} else {
560 		pcpu_item = zpcpu_base_to_offset(item);
561 		for (i = 0; i <= mp_maxid; i++)
562 			kasan_mark(zpcpu_get_cpu(pcpu_item, i), sz, rsz,
563 			    KASAN_GENERIC_REDZONE);
564 	}
565 }
566 
567 static void
568 kasan_mark_item_invalid(uma_zone_t zone, void *item)
569 {
570 	void *pcpu_item;
571 	size_t sz;
572 	int i;
573 
574 	if ((zone->uz_flags & UMA_ZONE_NOKASAN) != 0)
575 		return;
576 
577 	sz = roundup2(zone->uz_size, KASAN_SHADOW_SCALE);
578 	if ((zone->uz_flags & UMA_ZONE_PCPU) == 0) {
579 		kasan_mark(item, 0, sz, KASAN_UMA_FREED);
580 	} else {
581 		pcpu_item = zpcpu_base_to_offset(item);
582 		for (i = 0; i <= mp_maxid; i++)
583 			kasan_mark(zpcpu_get_cpu(pcpu_item, i), 0, sz,
584 			    KASAN_UMA_FREED);
585 	}
586 }
587 
588 static void
589 kasan_mark_slab_valid(uma_keg_t keg, void *mem)
590 {
591 	size_t sz;
592 
593 	if ((keg->uk_flags & UMA_ZONE_NOKASAN) == 0) {
594 		sz = keg->uk_ppera * PAGE_SIZE;
595 		kasan_mark(mem, sz, sz, 0);
596 	}
597 }
598 
599 static void
600 kasan_mark_slab_invalid(uma_keg_t keg, void *mem)
601 {
602 	size_t sz;
603 
604 	if ((keg->uk_flags & UMA_ZONE_NOKASAN) == 0) {
605 		if ((keg->uk_flags & UMA_ZFLAG_OFFPAGE) != 0)
606 			sz = keg->uk_ppera * PAGE_SIZE;
607 		else
608 			sz = keg->uk_pgoff;
609 		kasan_mark(mem, 0, sz, KASAN_UMA_FREED);
610 	}
611 }
612 #else /* !KASAN */
613 static void
614 kasan_mark_item_valid(uma_zone_t zone __unused, void *item __unused)
615 {
616 }
617 
618 static void
619 kasan_mark_item_invalid(uma_zone_t zone __unused, void *item __unused)
620 {
621 }
622 
623 static void
624 kasan_mark_slab_valid(uma_keg_t keg __unused, void *mem __unused)
625 {
626 }
627 
628 static void
629 kasan_mark_slab_invalid(uma_keg_t keg __unused, void *mem __unused)
630 {
631 }
632 #endif /* KASAN */
633 
634 #ifdef KMSAN
635 static inline void
636 kmsan_mark_item_uninitialized(uma_zone_t zone, void *item)
637 {
638 	void *pcpu_item;
639 	size_t sz;
640 	int i;
641 
642 	if ((zone->uz_flags &
643 	    (UMA_ZFLAG_CACHE | UMA_ZONE_SECONDARY | UMA_ZONE_MALLOC)) != 0) {
644 		/*
645 		 * Cache zones should not be instrumented by default, as UMA
646 		 * does not have enough information to do so correctly.
647 		 * Consumers can mark items themselves if it makes sense to do
648 		 * so.
649 		 *
650 		 * Items from secondary zones are initialized by the parent
651 		 * zone and thus cannot safely be marked by UMA.
652 		 *
653 		 * malloc zones are handled directly by malloc(9) and friends,
654 		 * since they can provide more precise origin tracking.
655 		 */
656 		return;
657 	}
658 	if (zone->uz_keg->uk_init != NULL) {
659 		/*
660 		 * By definition, initialized items cannot be marked.  The
661 		 * best we can do is mark items from these zones after they
662 		 * are freed to the keg.
663 		 */
664 		return;
665 	}
666 
667 	sz = zone->uz_size;
668 	if ((zone->uz_flags & UMA_ZONE_PCPU) == 0) {
669 		kmsan_orig(item, sz, KMSAN_TYPE_UMA, KMSAN_RET_ADDR);
670 		kmsan_mark(item, sz, KMSAN_STATE_UNINIT);
671 	} else {
672 		pcpu_item = zpcpu_base_to_offset(item);
673 		for (i = 0; i <= mp_maxid; i++) {
674 			kmsan_orig(zpcpu_get_cpu(pcpu_item, i), sz,
675 			    KMSAN_TYPE_UMA, KMSAN_RET_ADDR);
676 			kmsan_mark(zpcpu_get_cpu(pcpu_item, i), sz,
677 			    KMSAN_STATE_INITED);
678 		}
679 	}
680 }
681 #else /* !KMSAN */
682 static inline void
683 kmsan_mark_item_uninitialized(uma_zone_t zone __unused, void *item __unused)
684 {
685 }
686 #endif /* KMSAN */
687 
688 /*
689  * Acquire the domain lock and record contention.
690  */
691 static uma_zone_domain_t
692 zone_domain_lock(uma_zone_t zone, int domain)
693 {
694 	uma_zone_domain_t zdom;
695 	bool lockfail;
696 
697 	zdom = ZDOM_GET(zone, domain);
698 	lockfail = false;
699 	if (ZDOM_OWNED(zdom))
700 		lockfail = true;
701 	ZDOM_LOCK(zdom);
702 	/* This is unsynchronized.  The counter does not need to be precise. */
703 	if (lockfail && zone->uz_bucket_size < zone->uz_bucket_size_max)
704 		zone->uz_bucket_size++;
705 	return (zdom);
706 }
707 
708 /*
709  * Search for the domain with the least cached items and return it if it
710  * is out of balance with the preferred domain.
711  */
712 static __noinline int
713 zone_domain_lowest(uma_zone_t zone, int pref)
714 {
715 	long least, nitems, prefitems;
716 	int domain;
717 	int i;
718 
719 	prefitems = least = LONG_MAX;
720 	domain = 0;
721 	for (i = 0; i < vm_ndomains; i++) {
722 		nitems = ZDOM_GET(zone, i)->uzd_nitems;
723 		if (nitems < least) {
724 			domain = i;
725 			least = nitems;
726 		}
727 		if (domain == pref)
728 			prefitems = nitems;
729 	}
730 	if (prefitems < least * 2)
731 		return (pref);
732 
733 	return (domain);
734 }
735 
736 /*
737  * Search for the domain with the most cached items and return it or the
738  * preferred domain if it has enough to proceed.
739  */
740 static __noinline int
741 zone_domain_highest(uma_zone_t zone, int pref)
742 {
743 	long most, nitems;
744 	int domain;
745 	int i;
746 
747 	if (ZDOM_GET(zone, pref)->uzd_nitems > BUCKET_MAX)
748 		return (pref);
749 
750 	most = 0;
751 	domain = 0;
752 	for (i = 0; i < vm_ndomains; i++) {
753 		nitems = ZDOM_GET(zone, i)->uzd_nitems;
754 		if (nitems > most) {
755 			domain = i;
756 			most = nitems;
757 		}
758 	}
759 
760 	return (domain);
761 }
762 
763 /*
764  * Set the maximum imax value.
765  */
766 static void
767 zone_domain_imax_set(uma_zone_domain_t zdom, int nitems)
768 {
769 	long old;
770 
771 	old = zdom->uzd_imax;
772 	do {
773 		if (old >= nitems)
774 			return;
775 	} while (atomic_fcmpset_long(&zdom->uzd_imax, &old, nitems) == 0);
776 
777 	/*
778 	 * We are at new maximum, so do the last WSS update for the old
779 	 * bimin and prepare to measure next allocation batch.
780 	 */
781 	if (zdom->uzd_wss < old - zdom->uzd_bimin)
782 		zdom->uzd_wss = old - zdom->uzd_bimin;
783 	zdom->uzd_bimin = nitems;
784 }
785 
786 /*
787  * Attempt to satisfy an allocation by retrieving a full bucket from one of the
788  * zone's caches.  If a bucket is found the zone is not locked on return.
789  */
790 static uma_bucket_t
791 zone_fetch_bucket(uma_zone_t zone, uma_zone_domain_t zdom, bool reclaim)
792 {
793 	uma_bucket_t bucket;
794 	long cnt;
795 	int i;
796 	bool dtor = false;
797 
798 	ZDOM_LOCK_ASSERT(zdom);
799 
800 	if ((bucket = STAILQ_FIRST(&zdom->uzd_buckets)) == NULL)
801 		return (NULL);
802 
803 	/* SMR Buckets can not be re-used until readers expire. */
804 	if ((zone->uz_flags & UMA_ZONE_SMR) != 0 &&
805 	    bucket->ub_seq != SMR_SEQ_INVALID) {
806 		if (!smr_poll(zone->uz_smr, bucket->ub_seq, false))
807 			return (NULL);
808 		bucket->ub_seq = SMR_SEQ_INVALID;
809 		dtor = (zone->uz_dtor != NULL) || UMA_ALWAYS_CTORDTOR;
810 		if (STAILQ_NEXT(bucket, ub_link) != NULL)
811 			zdom->uzd_seq = STAILQ_NEXT(bucket, ub_link)->ub_seq;
812 	}
813 	STAILQ_REMOVE_HEAD(&zdom->uzd_buckets, ub_link);
814 
815 	KASSERT(zdom->uzd_nitems >= bucket->ub_cnt,
816 	    ("%s: item count underflow (%ld, %d)",
817 	    __func__, zdom->uzd_nitems, bucket->ub_cnt));
818 	KASSERT(bucket->ub_cnt > 0,
819 	    ("%s: empty bucket in bucket cache", __func__));
820 	zdom->uzd_nitems -= bucket->ub_cnt;
821 
822 	if (reclaim) {
823 		/*
824 		 * Shift the bounds of the current WSS interval to avoid
825 		 * perturbing the estimates.
826 		 */
827 		cnt = lmin(zdom->uzd_bimin, bucket->ub_cnt);
828 		atomic_subtract_long(&zdom->uzd_imax, cnt);
829 		zdom->uzd_bimin -= cnt;
830 		zdom->uzd_imin -= lmin(zdom->uzd_imin, bucket->ub_cnt);
831 		if (zdom->uzd_limin >= bucket->ub_cnt) {
832 			zdom->uzd_limin -= bucket->ub_cnt;
833 		} else {
834 			zdom->uzd_limin = 0;
835 			zdom->uzd_timin = 0;
836 		}
837 	} else if (zdom->uzd_bimin > zdom->uzd_nitems) {
838 		zdom->uzd_bimin = zdom->uzd_nitems;
839 		if (zdom->uzd_imin > zdom->uzd_nitems)
840 			zdom->uzd_imin = zdom->uzd_nitems;
841 	}
842 
843 	ZDOM_UNLOCK(zdom);
844 	if (dtor)
845 		for (i = 0; i < bucket->ub_cnt; i++)
846 			item_dtor(zone, bucket->ub_bucket[i], zone->uz_size,
847 			    NULL, SKIP_NONE);
848 
849 	return (bucket);
850 }
851 
852 /*
853  * Insert a full bucket into the specified cache.  The "ws" parameter indicates
854  * whether the bucket's contents should be counted as part of the zone's working
855  * set.  The bucket may be freed if it exceeds the bucket limit.
856  */
857 static void
858 zone_put_bucket(uma_zone_t zone, int domain, uma_bucket_t bucket, void *udata,
859     const bool ws)
860 {
861 	uma_zone_domain_t zdom;
862 
863 	/* We don't cache empty buckets.  This can happen after a reclaim. */
864 	if (bucket->ub_cnt == 0)
865 		goto out;
866 	zdom = zone_domain_lock(zone, domain);
867 
868 	/*
869 	 * Conditionally set the maximum number of items.
870 	 */
871 	zdom->uzd_nitems += bucket->ub_cnt;
872 	if (__predict_true(zdom->uzd_nitems < zone->uz_bucket_max)) {
873 		if (ws) {
874 			zone_domain_imax_set(zdom, zdom->uzd_nitems);
875 		} else {
876 			/*
877 			 * Shift the bounds of the current WSS interval to
878 			 * avoid perturbing the estimates.
879 			 */
880 			atomic_add_long(&zdom->uzd_imax, bucket->ub_cnt);
881 			zdom->uzd_imin += bucket->ub_cnt;
882 			zdom->uzd_bimin += bucket->ub_cnt;
883 			zdom->uzd_limin += bucket->ub_cnt;
884 		}
885 		if (STAILQ_EMPTY(&zdom->uzd_buckets))
886 			zdom->uzd_seq = bucket->ub_seq;
887 
888 		/*
889 		 * Try to promote reuse of recently used items.  For items
890 		 * protected by SMR, try to defer reuse to minimize polling.
891 		 */
892 		if (bucket->ub_seq == SMR_SEQ_INVALID)
893 			STAILQ_INSERT_HEAD(&zdom->uzd_buckets, bucket, ub_link);
894 		else
895 			STAILQ_INSERT_TAIL(&zdom->uzd_buckets, bucket, ub_link);
896 		ZDOM_UNLOCK(zdom);
897 		return;
898 	}
899 	zdom->uzd_nitems -= bucket->ub_cnt;
900 	ZDOM_UNLOCK(zdom);
901 out:
902 	bucket_free(zone, bucket, udata);
903 }
904 
905 /* Pops an item out of a per-cpu cache bucket. */
906 static inline void *
907 cache_bucket_pop(uma_cache_t cache, uma_cache_bucket_t bucket)
908 {
909 	void *item;
910 
911 	CRITICAL_ASSERT(curthread);
912 
913 	bucket->ucb_cnt--;
914 	item = bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt];
915 #ifdef INVARIANTS
916 	bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt] = NULL;
917 	KASSERT(item != NULL, ("uma_zalloc: Bucket pointer mangled."));
918 #endif
919 	cache->uc_allocs++;
920 
921 	return (item);
922 }
923 
924 /* Pushes an item into a per-cpu cache bucket. */
925 static inline void
926 cache_bucket_push(uma_cache_t cache, uma_cache_bucket_t bucket, void *item)
927 {
928 
929 	CRITICAL_ASSERT(curthread);
930 	KASSERT(bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt] == NULL,
931 	    ("uma_zfree: Freeing to non free bucket index."));
932 
933 	bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt] = item;
934 	bucket->ucb_cnt++;
935 	cache->uc_frees++;
936 }
937 
938 /*
939  * Unload a UMA bucket from a per-cpu cache.
940  */
941 static inline uma_bucket_t
942 cache_bucket_unload(uma_cache_bucket_t bucket)
943 {
944 	uma_bucket_t b;
945 
946 	b = bucket->ucb_bucket;
947 	if (b != NULL) {
948 		MPASS(b->ub_entries == bucket->ucb_entries);
949 		b->ub_cnt = bucket->ucb_cnt;
950 		bucket->ucb_bucket = NULL;
951 		bucket->ucb_entries = bucket->ucb_cnt = 0;
952 	}
953 
954 	return (b);
955 }
956 
957 static inline uma_bucket_t
958 cache_bucket_unload_alloc(uma_cache_t cache)
959 {
960 
961 	return (cache_bucket_unload(&cache->uc_allocbucket));
962 }
963 
964 static inline uma_bucket_t
965 cache_bucket_unload_free(uma_cache_t cache)
966 {
967 
968 	return (cache_bucket_unload(&cache->uc_freebucket));
969 }
970 
971 static inline uma_bucket_t
972 cache_bucket_unload_cross(uma_cache_t cache)
973 {
974 
975 	return (cache_bucket_unload(&cache->uc_crossbucket));
976 }
977 
978 /*
979  * Load a bucket into a per-cpu cache bucket.
980  */
981 static inline void
982 cache_bucket_load(uma_cache_bucket_t bucket, uma_bucket_t b)
983 {
984 
985 	CRITICAL_ASSERT(curthread);
986 	MPASS(bucket->ucb_bucket == NULL);
987 	MPASS(b->ub_seq == SMR_SEQ_INVALID);
988 
989 	bucket->ucb_bucket = b;
990 	bucket->ucb_cnt = b->ub_cnt;
991 	bucket->ucb_entries = b->ub_entries;
992 }
993 
994 static inline void
995 cache_bucket_load_alloc(uma_cache_t cache, uma_bucket_t b)
996 {
997 
998 	cache_bucket_load(&cache->uc_allocbucket, b);
999 }
1000 
1001 static inline void
1002 cache_bucket_load_free(uma_cache_t cache, uma_bucket_t b)
1003 {
1004 
1005 	cache_bucket_load(&cache->uc_freebucket, b);
1006 }
1007 
1008 #ifdef NUMA
1009 static inline void
1010 cache_bucket_load_cross(uma_cache_t cache, uma_bucket_t b)
1011 {
1012 
1013 	cache_bucket_load(&cache->uc_crossbucket, b);
1014 }
1015 #endif
1016 
1017 /*
1018  * Copy and preserve ucb_spare.
1019  */
1020 static inline void
1021 cache_bucket_copy(uma_cache_bucket_t b1, uma_cache_bucket_t b2)
1022 {
1023 
1024 	b1->ucb_bucket = b2->ucb_bucket;
1025 	b1->ucb_entries = b2->ucb_entries;
1026 	b1->ucb_cnt = b2->ucb_cnt;
1027 }
1028 
1029 /*
1030  * Swap two cache buckets.
1031  */
1032 static inline void
1033 cache_bucket_swap(uma_cache_bucket_t b1, uma_cache_bucket_t b2)
1034 {
1035 	struct uma_cache_bucket b3;
1036 
1037 	CRITICAL_ASSERT(curthread);
1038 
1039 	cache_bucket_copy(&b3, b1);
1040 	cache_bucket_copy(b1, b2);
1041 	cache_bucket_copy(b2, &b3);
1042 }
1043 
1044 /*
1045  * Attempt to fetch a bucket from a zone on behalf of the current cpu cache.
1046  */
1047 static uma_bucket_t
1048 cache_fetch_bucket(uma_zone_t zone, uma_cache_t cache, int domain)
1049 {
1050 	uma_zone_domain_t zdom;
1051 	uma_bucket_t bucket;
1052 	smr_seq_t seq;
1053 
1054 	/*
1055 	 * Avoid the lock if possible.
1056 	 */
1057 	zdom = ZDOM_GET(zone, domain);
1058 	if (zdom->uzd_nitems == 0)
1059 		return (NULL);
1060 
1061 	if ((cache_uz_flags(cache) & UMA_ZONE_SMR) != 0 &&
1062 	    (seq = atomic_load_32(&zdom->uzd_seq)) != SMR_SEQ_INVALID &&
1063 	    !smr_poll(zone->uz_smr, seq, false))
1064 		return (NULL);
1065 
1066 	/*
1067 	 * Check the zone's cache of buckets.
1068 	 */
1069 	zdom = zone_domain_lock(zone, domain);
1070 	if ((bucket = zone_fetch_bucket(zone, zdom, false)) != NULL)
1071 		return (bucket);
1072 	ZDOM_UNLOCK(zdom);
1073 
1074 	return (NULL);
1075 }
1076 
1077 static void
1078 zone_log_warning(uma_zone_t zone)
1079 {
1080 	static const struct timeval warninterval = { 300, 0 };
1081 
1082 	if (!zone_warnings || zone->uz_warning == NULL)
1083 		return;
1084 
1085 	if (ratecheck(&zone->uz_ratecheck, &warninterval))
1086 		printf("[zone: %s] %s\n", zone->uz_name, zone->uz_warning);
1087 }
1088 
1089 static inline void
1090 zone_maxaction(uma_zone_t zone)
1091 {
1092 
1093 	if (zone->uz_maxaction.ta_func != NULL)
1094 		taskqueue_enqueue(taskqueue_thread, &zone->uz_maxaction);
1095 }
1096 
1097 /*
1098  * Routine called by timeout which is used to fire off some time interval
1099  * based calculations.  (stats, hash size, etc.)
1100  *
1101  * Arguments:
1102  *	arg   Unused
1103  *
1104  * Returns:
1105  *	Nothing
1106  */
1107 static void
1108 uma_timeout(void *context __unused, int pending __unused)
1109 {
1110 	bucket_enable();
1111 	zone_foreach(zone_timeout, NULL);
1112 
1113 	/* Reschedule this event */
1114 	taskqueue_enqueue_timeout(taskqueue_thread, &uma_timeout_task,
1115 	    UMA_TIMEOUT * hz);
1116 }
1117 
1118 /*
1119  * Update the working set size estimates for the zone's bucket cache.
1120  * The constants chosen here are somewhat arbitrary.
1121  */
1122 static void
1123 zone_domain_update_wss(uma_zone_domain_t zdom)
1124 {
1125 	long m;
1126 
1127 	ZDOM_LOCK_ASSERT(zdom);
1128 	MPASS(zdom->uzd_imax >= zdom->uzd_nitems);
1129 	MPASS(zdom->uzd_nitems >= zdom->uzd_bimin);
1130 	MPASS(zdom->uzd_bimin >= zdom->uzd_imin);
1131 
1132 	/*
1133 	 * Estimate WSS as modified moving average of biggest allocation
1134 	 * batches for each period over few minutes (UMA_TIMEOUT of 20s).
1135 	 */
1136 	zdom->uzd_wss = lmax(zdom->uzd_wss * 3 / 4,
1137 	    zdom->uzd_imax - zdom->uzd_bimin);
1138 
1139 	/*
1140 	 * Estimate longtime minimum item count as a combination of recent
1141 	 * minimum item count, adjusted by WSS for safety, and the modified
1142 	 * moving average over the last several hours (UMA_TIMEOUT of 20s).
1143 	 * timin measures time since limin tried to go negative, that means
1144 	 * we were dangerously close to or got out of cache.
1145 	 */
1146 	m = zdom->uzd_imin - zdom->uzd_wss;
1147 	if (m >= 0) {
1148 		if (zdom->uzd_limin >= m)
1149 			zdom->uzd_limin = m;
1150 		else
1151 			zdom->uzd_limin = (m + zdom->uzd_limin * 255) / 256;
1152 		zdom->uzd_timin++;
1153 	} else {
1154 		zdom->uzd_limin = 0;
1155 		zdom->uzd_timin = 0;
1156 	}
1157 
1158 	/* To reduce period edge effects on WSS keep half of the imax. */
1159 	atomic_subtract_long(&zdom->uzd_imax,
1160 	    (zdom->uzd_imax - zdom->uzd_nitems + 1) / 2);
1161 	zdom->uzd_imin = zdom->uzd_bimin = zdom->uzd_nitems;
1162 }
1163 
1164 /*
1165  * Routine to perform timeout driven calculations.  This expands the
1166  * hashes and does per cpu statistics aggregation.
1167  *
1168  *  Returns nothing.
1169  */
1170 static void
1171 zone_timeout(uma_zone_t zone, void *unused)
1172 {
1173 	uma_keg_t keg;
1174 	u_int slabs, pages;
1175 
1176 	if ((zone->uz_flags & UMA_ZFLAG_HASH) == 0)
1177 		goto trim;
1178 
1179 	keg = zone->uz_keg;
1180 
1181 	/*
1182 	 * Hash zones are non-numa by definition so the first domain
1183 	 * is the only one present.
1184 	 */
1185 	KEG_LOCK(keg, 0);
1186 	pages = keg->uk_domain[0].ud_pages;
1187 
1188 	/*
1189 	 * Expand the keg hash table.
1190 	 *
1191 	 * This is done if the number of slabs is larger than the hash size.
1192 	 * What I'm trying to do here is completely reduce collisions.  This
1193 	 * may be a little aggressive.  Should I allow for two collisions max?
1194 	 */
1195 	if ((slabs = pages / keg->uk_ppera) > keg->uk_hash.uh_hashsize) {
1196 		struct uma_hash newhash;
1197 		struct uma_hash oldhash;
1198 		int ret;
1199 
1200 		/*
1201 		 * This is so involved because allocating and freeing
1202 		 * while the keg lock is held will lead to deadlock.
1203 		 * I have to do everything in stages and check for
1204 		 * races.
1205 		 */
1206 		KEG_UNLOCK(keg, 0);
1207 		ret = hash_alloc(&newhash, 1 << fls(slabs));
1208 		KEG_LOCK(keg, 0);
1209 		if (ret) {
1210 			if (hash_expand(&keg->uk_hash, &newhash)) {
1211 				oldhash = keg->uk_hash;
1212 				keg->uk_hash = newhash;
1213 			} else
1214 				oldhash = newhash;
1215 
1216 			KEG_UNLOCK(keg, 0);
1217 			hash_free(&oldhash);
1218 			goto trim;
1219 		}
1220 	}
1221 	KEG_UNLOCK(keg, 0);
1222 
1223 trim:
1224 	/* Trim caches not used for a long time. */
1225 	if ((zone->uz_flags & UMA_ZONE_UNMANAGED) == 0) {
1226 		for (int i = 0; i < vm_ndomains; i++) {
1227 			if (bucket_cache_reclaim_domain(zone, false, false, i) &&
1228 			    (zone->uz_flags & UMA_ZFLAG_CACHE) == 0)
1229 				keg_drain(zone->uz_keg, i);
1230 		}
1231 	}
1232 }
1233 
1234 /*
1235  * Allocate and zero fill the next sized hash table from the appropriate
1236  * backing store.
1237  *
1238  * Arguments:
1239  *	hash  A new hash structure with the old hash size in uh_hashsize
1240  *
1241  * Returns:
1242  *	1 on success and 0 on failure.
1243  */
1244 static int
1245 hash_alloc(struct uma_hash *hash, u_int size)
1246 {
1247 	size_t alloc;
1248 
1249 	KASSERT(powerof2(size), ("hash size must be power of 2"));
1250 	if (size > UMA_HASH_SIZE_INIT)  {
1251 		hash->uh_hashsize = size;
1252 		alloc = sizeof(hash->uh_slab_hash[0]) * hash->uh_hashsize;
1253 		hash->uh_slab_hash = malloc(alloc, M_UMAHASH, M_NOWAIT);
1254 	} else {
1255 		alloc = sizeof(hash->uh_slab_hash[0]) * UMA_HASH_SIZE_INIT;
1256 		hash->uh_slab_hash = zone_alloc_item(hashzone, NULL,
1257 		    UMA_ANYDOMAIN, M_WAITOK);
1258 		hash->uh_hashsize = UMA_HASH_SIZE_INIT;
1259 	}
1260 	if (hash->uh_slab_hash) {
1261 		bzero(hash->uh_slab_hash, alloc);
1262 		hash->uh_hashmask = hash->uh_hashsize - 1;
1263 		return (1);
1264 	}
1265 
1266 	return (0);
1267 }
1268 
1269 /*
1270  * Expands the hash table for HASH zones.  This is done from zone_timeout
1271  * to reduce collisions.  This must not be done in the regular allocation
1272  * path, otherwise, we can recurse on the vm while allocating pages.
1273  *
1274  * Arguments:
1275  *	oldhash  The hash you want to expand
1276  *	newhash  The hash structure for the new table
1277  *
1278  * Returns:
1279  *	Nothing
1280  *
1281  * Discussion:
1282  */
1283 static int
1284 hash_expand(struct uma_hash *oldhash, struct uma_hash *newhash)
1285 {
1286 	uma_hash_slab_t slab;
1287 	u_int hval;
1288 	u_int idx;
1289 
1290 	if (!newhash->uh_slab_hash)
1291 		return (0);
1292 
1293 	if (oldhash->uh_hashsize >= newhash->uh_hashsize)
1294 		return (0);
1295 
1296 	/*
1297 	 * I need to investigate hash algorithms for resizing without a
1298 	 * full rehash.
1299 	 */
1300 
1301 	for (idx = 0; idx < oldhash->uh_hashsize; idx++)
1302 		while (!LIST_EMPTY(&oldhash->uh_slab_hash[idx])) {
1303 			slab = LIST_FIRST(&oldhash->uh_slab_hash[idx]);
1304 			LIST_REMOVE(slab, uhs_hlink);
1305 			hval = UMA_HASH(newhash, slab->uhs_data);
1306 			LIST_INSERT_HEAD(&newhash->uh_slab_hash[hval],
1307 			    slab, uhs_hlink);
1308 		}
1309 
1310 	return (1);
1311 }
1312 
1313 /*
1314  * Free the hash bucket to the appropriate backing store.
1315  *
1316  * Arguments:
1317  *	slab_hash  The hash bucket we're freeing
1318  *	hashsize   The number of entries in that hash bucket
1319  *
1320  * Returns:
1321  *	Nothing
1322  */
1323 static void
1324 hash_free(struct uma_hash *hash)
1325 {
1326 	if (hash->uh_slab_hash == NULL)
1327 		return;
1328 	if (hash->uh_hashsize == UMA_HASH_SIZE_INIT)
1329 		zone_free_item(hashzone, hash->uh_slab_hash, NULL, SKIP_NONE);
1330 	else
1331 		free(hash->uh_slab_hash, M_UMAHASH);
1332 }
1333 
1334 /*
1335  * Frees all outstanding items in a bucket
1336  *
1337  * Arguments:
1338  *	zone   The zone to free to, must be unlocked.
1339  *	bucket The free/alloc bucket with items.
1340  *
1341  * Returns:
1342  *	Nothing
1343  */
1344 static void
1345 bucket_drain(uma_zone_t zone, uma_bucket_t bucket)
1346 {
1347 	int i;
1348 
1349 	if (bucket->ub_cnt == 0)
1350 		return;
1351 
1352 	if ((zone->uz_flags & UMA_ZONE_SMR) != 0 &&
1353 	    bucket->ub_seq != SMR_SEQ_INVALID) {
1354 		smr_wait(zone->uz_smr, bucket->ub_seq);
1355 		bucket->ub_seq = SMR_SEQ_INVALID;
1356 		for (i = 0; i < bucket->ub_cnt; i++)
1357 			item_dtor(zone, bucket->ub_bucket[i],
1358 			    zone->uz_size, NULL, SKIP_NONE);
1359 	}
1360 	if (zone->uz_fini)
1361 		for (i = 0; i < bucket->ub_cnt; i++) {
1362 			kasan_mark_item_valid(zone, bucket->ub_bucket[i]);
1363 			zone->uz_fini(bucket->ub_bucket[i], zone->uz_size);
1364 			kasan_mark_item_invalid(zone, bucket->ub_bucket[i]);
1365 		}
1366 	zone->uz_release(zone->uz_arg, bucket->ub_bucket, bucket->ub_cnt);
1367 	if (zone->uz_max_items > 0)
1368 		zone_free_limit(zone, bucket->ub_cnt);
1369 #ifdef INVARIANTS
1370 	bzero(bucket->ub_bucket, sizeof(void *) * bucket->ub_cnt);
1371 #endif
1372 	bucket->ub_cnt = 0;
1373 }
1374 
1375 /*
1376  * Drains the per cpu caches for a zone.
1377  *
1378  * NOTE: This may only be called while the zone is being torn down, and not
1379  * during normal operation.  This is necessary in order that we do not have
1380  * to migrate CPUs to drain the per-CPU caches.
1381  *
1382  * Arguments:
1383  *	zone     The zone to drain, must be unlocked.
1384  *
1385  * Returns:
1386  *	Nothing
1387  */
1388 static void
1389 cache_drain(uma_zone_t zone)
1390 {
1391 	uma_cache_t cache;
1392 	uma_bucket_t bucket;
1393 	smr_seq_t seq;
1394 	int cpu;
1395 
1396 	/*
1397 	 * XXX: It is safe to not lock the per-CPU caches, because we're
1398 	 * tearing down the zone anyway.  I.e., there will be no further use
1399 	 * of the caches at this point.
1400 	 *
1401 	 * XXX: It would good to be able to assert that the zone is being
1402 	 * torn down to prevent improper use of cache_drain().
1403 	 */
1404 	seq = SMR_SEQ_INVALID;
1405 	if ((zone->uz_flags & UMA_ZONE_SMR) != 0)
1406 		seq = smr_advance(zone->uz_smr);
1407 	CPU_FOREACH(cpu) {
1408 		cache = &zone->uz_cpu[cpu];
1409 		bucket = cache_bucket_unload_alloc(cache);
1410 		if (bucket != NULL)
1411 			bucket_free(zone, bucket, NULL);
1412 		bucket = cache_bucket_unload_free(cache);
1413 		if (bucket != NULL) {
1414 			bucket->ub_seq = seq;
1415 			bucket_free(zone, bucket, NULL);
1416 		}
1417 		bucket = cache_bucket_unload_cross(cache);
1418 		if (bucket != NULL) {
1419 			bucket->ub_seq = seq;
1420 			bucket_free(zone, bucket, NULL);
1421 		}
1422 	}
1423 	bucket_cache_reclaim(zone, true, UMA_ANYDOMAIN);
1424 }
1425 
1426 static void
1427 cache_shrink(uma_zone_t zone, void *unused)
1428 {
1429 
1430 	if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
1431 		return;
1432 
1433 	ZONE_LOCK(zone);
1434 	zone->uz_bucket_size =
1435 	    (zone->uz_bucket_size_min + zone->uz_bucket_size) / 2;
1436 	ZONE_UNLOCK(zone);
1437 }
1438 
1439 static void
1440 cache_drain_safe_cpu(uma_zone_t zone, void *unused)
1441 {
1442 	uma_cache_t cache;
1443 	uma_bucket_t b1, b2, b3;
1444 	int domain;
1445 
1446 	if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
1447 		return;
1448 
1449 	b1 = b2 = b3 = NULL;
1450 	critical_enter();
1451 	cache = &zone->uz_cpu[curcpu];
1452 	domain = PCPU_GET(domain);
1453 	b1 = cache_bucket_unload_alloc(cache);
1454 
1455 	/*
1456 	 * Don't flush SMR zone buckets.  This leaves the zone without a
1457 	 * bucket and forces every free to synchronize().
1458 	 */
1459 	if ((zone->uz_flags & UMA_ZONE_SMR) == 0) {
1460 		b2 = cache_bucket_unload_free(cache);
1461 		b3 = cache_bucket_unload_cross(cache);
1462 	}
1463 	critical_exit();
1464 
1465 	if (b1 != NULL)
1466 		zone_free_bucket(zone, b1, NULL, domain, false);
1467 	if (b2 != NULL)
1468 		zone_free_bucket(zone, b2, NULL, domain, false);
1469 	if (b3 != NULL) {
1470 		/* Adjust the domain so it goes to zone_free_cross. */
1471 		domain = (domain + 1) % vm_ndomains;
1472 		zone_free_bucket(zone, b3, NULL, domain, false);
1473 	}
1474 }
1475 
1476 /*
1477  * Safely drain per-CPU caches of a zone(s) to alloc bucket.
1478  * This is an expensive call because it needs to bind to all CPUs
1479  * one by one and enter a critical section on each of them in order
1480  * to safely access their cache buckets.
1481  * Zone lock must not be held on call this function.
1482  */
1483 static void
1484 pcpu_cache_drain_safe(uma_zone_t zone)
1485 {
1486 	int cpu;
1487 
1488 	/*
1489 	 * Polite bucket sizes shrinking was not enough, shrink aggressively.
1490 	 */
1491 	if (zone)
1492 		cache_shrink(zone, NULL);
1493 	else
1494 		zone_foreach(cache_shrink, NULL);
1495 
1496 	CPU_FOREACH(cpu) {
1497 		thread_lock(curthread);
1498 		sched_bind(curthread, cpu);
1499 		thread_unlock(curthread);
1500 
1501 		if (zone)
1502 			cache_drain_safe_cpu(zone, NULL);
1503 		else
1504 			zone_foreach(cache_drain_safe_cpu, NULL);
1505 	}
1506 	thread_lock(curthread);
1507 	sched_unbind(curthread);
1508 	thread_unlock(curthread);
1509 }
1510 
1511 /*
1512  * Reclaim cached buckets from a zone.  All buckets are reclaimed if the caller
1513  * requested a drain, otherwise the per-domain caches are trimmed to either
1514  * estimated working set size.
1515  */
1516 static bool
1517 bucket_cache_reclaim_domain(uma_zone_t zone, bool drain, bool trim, int domain)
1518 {
1519 	uma_zone_domain_t zdom;
1520 	uma_bucket_t bucket;
1521 	long target;
1522 	bool done = false;
1523 
1524 	/*
1525 	 * The cross bucket is partially filled and not part of
1526 	 * the item count.  Reclaim it individually here.
1527 	 */
1528 	zdom = ZDOM_GET(zone, domain);
1529 	if ((zone->uz_flags & UMA_ZONE_SMR) == 0 || drain) {
1530 		ZONE_CROSS_LOCK(zone);
1531 		bucket = zdom->uzd_cross;
1532 		zdom->uzd_cross = NULL;
1533 		ZONE_CROSS_UNLOCK(zone);
1534 		if (bucket != NULL)
1535 			bucket_free(zone, bucket, NULL);
1536 	}
1537 
1538 	/*
1539 	 * If we were asked to drain the zone, we are done only once
1540 	 * this bucket cache is empty.  If trim, we reclaim items in
1541 	 * excess of the zone's estimated working set size.  Multiple
1542 	 * consecutive calls will shrink the WSS and so reclaim more.
1543 	 * If neither drain nor trim, then voluntarily reclaim 1/4
1544 	 * (to reduce first spike) of items not used for a long time.
1545 	 */
1546 	ZDOM_LOCK(zdom);
1547 	zone_domain_update_wss(zdom);
1548 	if (drain)
1549 		target = 0;
1550 	else if (trim)
1551 		target = zdom->uzd_wss;
1552 	else if (zdom->uzd_timin > 900 / UMA_TIMEOUT)
1553 		target = zdom->uzd_nitems - zdom->uzd_limin / 4;
1554 	else {
1555 		ZDOM_UNLOCK(zdom);
1556 		return (done);
1557 	}
1558 	while ((bucket = STAILQ_FIRST(&zdom->uzd_buckets)) != NULL &&
1559 	    zdom->uzd_nitems >= target + bucket->ub_cnt) {
1560 		bucket = zone_fetch_bucket(zone, zdom, true);
1561 		if (bucket == NULL)
1562 			break;
1563 		bucket_free(zone, bucket, NULL);
1564 		done = true;
1565 		ZDOM_LOCK(zdom);
1566 	}
1567 	ZDOM_UNLOCK(zdom);
1568 	return (done);
1569 }
1570 
1571 static void
1572 bucket_cache_reclaim(uma_zone_t zone, bool drain, int domain)
1573 {
1574 	int i;
1575 
1576 	/*
1577 	 * Shrink the zone bucket size to ensure that the per-CPU caches
1578 	 * don't grow too large.
1579 	 */
1580 	if (zone->uz_bucket_size > zone->uz_bucket_size_min)
1581 		zone->uz_bucket_size--;
1582 
1583 	if (domain != UMA_ANYDOMAIN &&
1584 	    (zone->uz_flags & UMA_ZONE_ROUNDROBIN) == 0) {
1585 		bucket_cache_reclaim_domain(zone, drain, true, domain);
1586 	} else {
1587 		for (i = 0; i < vm_ndomains; i++)
1588 			bucket_cache_reclaim_domain(zone, drain, true, i);
1589 	}
1590 }
1591 
1592 static void
1593 keg_free_slab(uma_keg_t keg, uma_slab_t slab, int start)
1594 {
1595 	uint8_t *mem;
1596 	size_t size;
1597 	int i;
1598 	uint8_t flags;
1599 
1600 	CTR4(KTR_UMA, "keg_free_slab keg %s(%p) slab %p, returning %d bytes",
1601 	    keg->uk_name, keg, slab, PAGE_SIZE * keg->uk_ppera);
1602 
1603 	mem = slab_data(slab, keg);
1604 	size = PAGE_SIZE * keg->uk_ppera;
1605 
1606 	kasan_mark_slab_valid(keg, mem);
1607 	if (keg->uk_fini != NULL) {
1608 		for (i = start - 1; i > -1; i--)
1609 #ifdef INVARIANTS
1610 		/*
1611 		 * trash_fini implies that dtor was trash_dtor. trash_fini
1612 		 * would check that memory hasn't been modified since free,
1613 		 * which executed trash_dtor.
1614 		 * That's why we need to run uma_dbg_kskip() check here,
1615 		 * albeit we don't make skip check for other init/fini
1616 		 * invocations.
1617 		 */
1618 		if (!uma_dbg_kskip(keg, slab_item(slab, keg, i)) ||
1619 		    keg->uk_fini != trash_fini)
1620 #endif
1621 			keg->uk_fini(slab_item(slab, keg, i), keg->uk_size);
1622 	}
1623 	flags = slab->us_flags;
1624 	if (keg->uk_flags & UMA_ZFLAG_OFFPAGE) {
1625 		zone_free_item(slabzone(keg->uk_ipers), slab_tohashslab(slab),
1626 		    NULL, SKIP_NONE);
1627 	}
1628 	keg->uk_freef(mem, size, flags);
1629 	uma_total_dec(size);
1630 }
1631 
1632 static void
1633 keg_drain_domain(uma_keg_t keg, int domain)
1634 {
1635 	struct slabhead freeslabs;
1636 	uma_domain_t dom;
1637 	uma_slab_t slab, tmp;
1638 	uint32_t i, stofree, stokeep, partial;
1639 
1640 	dom = &keg->uk_domain[domain];
1641 	LIST_INIT(&freeslabs);
1642 
1643 	CTR4(KTR_UMA, "keg_drain %s(%p) domain %d free items: %u",
1644 	    keg->uk_name, keg, domain, dom->ud_free_items);
1645 
1646 	KEG_LOCK(keg, domain);
1647 
1648 	/*
1649 	 * Are the free items in partially allocated slabs sufficient to meet
1650 	 * the reserve? If not, compute the number of fully free slabs that must
1651 	 * be kept.
1652 	 */
1653 	partial = dom->ud_free_items - dom->ud_free_slabs * keg->uk_ipers;
1654 	if (partial < keg->uk_reserve) {
1655 		stokeep = min(dom->ud_free_slabs,
1656 		    howmany(keg->uk_reserve - partial, keg->uk_ipers));
1657 	} else {
1658 		stokeep = 0;
1659 	}
1660 	stofree = dom->ud_free_slabs - stokeep;
1661 
1662 	/*
1663 	 * Partition the free slabs into two sets: those that must be kept in
1664 	 * order to maintain the reserve, and those that may be released back to
1665 	 * the system.  Since one set may be much larger than the other,
1666 	 * populate the smaller of the two sets and swap them if necessary.
1667 	 */
1668 	for (i = min(stofree, stokeep); i > 0; i--) {
1669 		slab = LIST_FIRST(&dom->ud_free_slab);
1670 		LIST_REMOVE(slab, us_link);
1671 		LIST_INSERT_HEAD(&freeslabs, slab, us_link);
1672 	}
1673 	if (stofree > stokeep)
1674 		LIST_SWAP(&freeslabs, &dom->ud_free_slab, uma_slab, us_link);
1675 
1676 	if ((keg->uk_flags & UMA_ZFLAG_HASH) != 0) {
1677 		LIST_FOREACH(slab, &freeslabs, us_link)
1678 			UMA_HASH_REMOVE(&keg->uk_hash, slab);
1679 	}
1680 	dom->ud_free_items -= stofree * keg->uk_ipers;
1681 	dom->ud_free_slabs -= stofree;
1682 	dom->ud_pages -= stofree * keg->uk_ppera;
1683 	KEG_UNLOCK(keg, domain);
1684 
1685 	LIST_FOREACH_SAFE(slab, &freeslabs, us_link, tmp)
1686 		keg_free_slab(keg, slab, keg->uk_ipers);
1687 }
1688 
1689 /*
1690  * Frees pages from a keg back to the system.  This is done on demand from
1691  * the pageout daemon.
1692  *
1693  * Returns nothing.
1694  */
1695 static void
1696 keg_drain(uma_keg_t keg, int domain)
1697 {
1698 	int i;
1699 
1700 	if ((keg->uk_flags & UMA_ZONE_NOFREE) != 0)
1701 		return;
1702 	if (domain != UMA_ANYDOMAIN) {
1703 		keg_drain_domain(keg, domain);
1704 	} else {
1705 		for (i = 0; i < vm_ndomains; i++)
1706 			keg_drain_domain(keg, i);
1707 	}
1708 }
1709 
1710 static void
1711 zone_reclaim(uma_zone_t zone, int domain, int waitok, bool drain)
1712 {
1713 	/*
1714 	 * Count active reclaim operations in order to interlock with
1715 	 * zone_dtor(), which removes the zone from global lists before
1716 	 * attempting to reclaim items itself.
1717 	 *
1718 	 * The zone may be destroyed while sleeping, so only zone_dtor() should
1719 	 * specify M_WAITOK.
1720 	 */
1721 	ZONE_LOCK(zone);
1722 	if (waitok == M_WAITOK) {
1723 		while (zone->uz_reclaimers > 0)
1724 			msleep(zone, ZONE_LOCKPTR(zone), PVM, "zonedrain", 1);
1725 	}
1726 	zone->uz_reclaimers++;
1727 	ZONE_UNLOCK(zone);
1728 	bucket_cache_reclaim(zone, drain, domain);
1729 
1730 	if ((zone->uz_flags & UMA_ZFLAG_CACHE) == 0)
1731 		keg_drain(zone->uz_keg, domain);
1732 	ZONE_LOCK(zone);
1733 	zone->uz_reclaimers--;
1734 	if (zone->uz_reclaimers == 0)
1735 		wakeup(zone);
1736 	ZONE_UNLOCK(zone);
1737 }
1738 
1739 /*
1740  * Allocate a new slab for a keg and inserts it into the partial slab list.
1741  * The keg should be unlocked on entry.  If the allocation succeeds it will
1742  * be locked on return.
1743  *
1744  * Arguments:
1745  *	flags   Wait flags for the item initialization routine
1746  *	aflags  Wait flags for the slab allocation
1747  *
1748  * Returns:
1749  *	The slab that was allocated or NULL if there is no memory and the
1750  *	caller specified M_NOWAIT.
1751  */
1752 static uma_slab_t
1753 keg_alloc_slab(uma_keg_t keg, uma_zone_t zone, int domain, int flags,
1754     int aflags)
1755 {
1756 	uma_domain_t dom;
1757 	uma_slab_t slab;
1758 	unsigned long size;
1759 	uint8_t *mem;
1760 	uint8_t sflags;
1761 	int i;
1762 
1763 	TSENTER();
1764 
1765 	KASSERT(domain >= 0 && domain < vm_ndomains,
1766 	    ("keg_alloc_slab: domain %d out of range", domain));
1767 
1768 	slab = NULL;
1769 	mem = NULL;
1770 	if (keg->uk_flags & UMA_ZFLAG_OFFPAGE) {
1771 		uma_hash_slab_t hslab;
1772 		hslab = zone_alloc_item(slabzone(keg->uk_ipers), NULL,
1773 		    domain, aflags);
1774 		if (hslab == NULL)
1775 			goto fail;
1776 		slab = &hslab->uhs_slab;
1777 	}
1778 
1779 	/*
1780 	 * This reproduces the old vm_zone behavior of zero filling pages the
1781 	 * first time they are added to a zone.
1782 	 *
1783 	 * Malloced items are zeroed in uma_zalloc.
1784 	 */
1785 
1786 	if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
1787 		aflags |= M_ZERO;
1788 	else
1789 		aflags &= ~M_ZERO;
1790 
1791 	if (keg->uk_flags & UMA_ZONE_NODUMP)
1792 		aflags |= M_NODUMP;
1793 
1794 	/* zone is passed for legacy reasons. */
1795 	size = keg->uk_ppera * PAGE_SIZE;
1796 	mem = keg->uk_allocf(zone, size, domain, &sflags, aflags);
1797 	if (mem == NULL) {
1798 		if (keg->uk_flags & UMA_ZFLAG_OFFPAGE)
1799 			zone_free_item(slabzone(keg->uk_ipers),
1800 			    slab_tohashslab(slab), NULL, SKIP_NONE);
1801 		goto fail;
1802 	}
1803 	uma_total_inc(size);
1804 
1805 	/* For HASH zones all pages go to the same uma_domain. */
1806 	if ((keg->uk_flags & UMA_ZFLAG_HASH) != 0)
1807 		domain = 0;
1808 
1809 	kmsan_mark(mem, size,
1810 	    (aflags & M_ZERO) != 0 ? KMSAN_STATE_INITED : KMSAN_STATE_UNINIT);
1811 
1812 	/* Point the slab into the allocated memory */
1813 	if (!(keg->uk_flags & UMA_ZFLAG_OFFPAGE))
1814 		slab = (uma_slab_t)(mem + keg->uk_pgoff);
1815 	else
1816 		slab_tohashslab(slab)->uhs_data = mem;
1817 
1818 	if (keg->uk_flags & UMA_ZFLAG_VTOSLAB)
1819 		for (i = 0; i < keg->uk_ppera; i++)
1820 			vsetzoneslab((vm_offset_t)mem + (i * PAGE_SIZE),
1821 			    zone, slab);
1822 
1823 	slab->us_freecount = keg->uk_ipers;
1824 	slab->us_flags = sflags;
1825 	slab->us_domain = domain;
1826 
1827 	BIT_FILL(keg->uk_ipers, &slab->us_free);
1828 #ifdef INVARIANTS
1829 	BIT_ZERO(keg->uk_ipers, slab_dbg_bits(slab, keg));
1830 #endif
1831 
1832 	if (keg->uk_init != NULL) {
1833 		for (i = 0; i < keg->uk_ipers; i++)
1834 			if (keg->uk_init(slab_item(slab, keg, i),
1835 			    keg->uk_size, flags) != 0)
1836 				break;
1837 		if (i != keg->uk_ipers) {
1838 			keg_free_slab(keg, slab, i);
1839 			goto fail;
1840 		}
1841 	}
1842 	kasan_mark_slab_invalid(keg, mem);
1843 	KEG_LOCK(keg, domain);
1844 
1845 	CTR3(KTR_UMA, "keg_alloc_slab: allocated slab %p for %s(%p)",
1846 	    slab, keg->uk_name, keg);
1847 
1848 	if (keg->uk_flags & UMA_ZFLAG_HASH)
1849 		UMA_HASH_INSERT(&keg->uk_hash, slab, mem);
1850 
1851 	/*
1852 	 * If we got a slab here it's safe to mark it partially used
1853 	 * and return.  We assume that the caller is going to remove
1854 	 * at least one item.
1855 	 */
1856 	dom = &keg->uk_domain[domain];
1857 	LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
1858 	dom->ud_pages += keg->uk_ppera;
1859 	dom->ud_free_items += keg->uk_ipers;
1860 
1861 	TSEXIT();
1862 	return (slab);
1863 
1864 fail:
1865 	return (NULL);
1866 }
1867 
1868 /*
1869  * This function is intended to be used early on in place of page_alloc().  It
1870  * performs contiguous physical memory allocations and uses a bump allocator for
1871  * KVA, so is usable before the kernel map is initialized.
1872  */
1873 static void *
1874 startup_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
1875     int wait)
1876 {
1877 	vm_paddr_t pa;
1878 	vm_page_t m;
1879 	int i, pages;
1880 
1881 	pages = howmany(bytes, PAGE_SIZE);
1882 	KASSERT(pages > 0, ("%s can't reserve 0 pages", __func__));
1883 
1884 	*pflag = UMA_SLAB_BOOT;
1885 	m = vm_page_alloc_noobj_contig_domain(domain, malloc2vm_flags(wait) |
1886 	    VM_ALLOC_WIRED, pages, (vm_paddr_t)0, ~(vm_paddr_t)0, 1, 0,
1887 	    VM_MEMATTR_DEFAULT);
1888 	if (m == NULL)
1889 		return (NULL);
1890 
1891 	pa = VM_PAGE_TO_PHYS(m);
1892 	for (i = 0; i < pages; i++, pa += PAGE_SIZE) {
1893 #if defined(__aarch64__) || defined(__amd64__) || \
1894     defined(__riscv) || defined(__powerpc64__)
1895 		if ((wait & M_NODUMP) == 0)
1896 			dump_add_page(pa);
1897 #endif
1898 	}
1899 
1900 	/* Allocate KVA and indirectly advance bootmem. */
1901 	return ((void *)pmap_map(&bootmem, m->phys_addr,
1902 	    m->phys_addr + (pages * PAGE_SIZE), VM_PROT_READ | VM_PROT_WRITE));
1903 }
1904 
1905 static void
1906 startup_free(void *mem, vm_size_t bytes)
1907 {
1908 	vm_offset_t va;
1909 	vm_page_t m;
1910 
1911 	va = (vm_offset_t)mem;
1912 	m = PHYS_TO_VM_PAGE(pmap_kextract(va));
1913 
1914 	/*
1915 	 * startup_alloc() returns direct-mapped slabs on some platforms.  Avoid
1916 	 * unmapping ranges of the direct map.
1917 	 */
1918 	if (va >= bootstart && va + bytes <= bootmem)
1919 		pmap_remove(kernel_pmap, va, va + bytes);
1920 	for (; bytes != 0; bytes -= PAGE_SIZE, m++) {
1921 #if defined(__aarch64__) || defined(__amd64__) || \
1922     defined(__riscv) || defined(__powerpc64__)
1923 		dump_drop_page(VM_PAGE_TO_PHYS(m));
1924 #endif
1925 		vm_page_unwire_noq(m);
1926 		vm_page_free(m);
1927 	}
1928 }
1929 
1930 /*
1931  * Allocates a number of pages from the system
1932  *
1933  * Arguments:
1934  *	bytes  The number of bytes requested
1935  *	wait  Shall we wait?
1936  *
1937  * Returns:
1938  *	A pointer to the alloced memory or possibly
1939  *	NULL if M_NOWAIT is set.
1940  */
1941 static void *
1942 page_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
1943     int wait)
1944 {
1945 	void *p;	/* Returned page */
1946 
1947 	*pflag = UMA_SLAB_KERNEL;
1948 	p = kmem_malloc_domainset(DOMAINSET_FIXED(domain), bytes, wait);
1949 
1950 	return (p);
1951 }
1952 
1953 static void *
1954 pcpu_page_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
1955     int wait)
1956 {
1957 	struct pglist alloctail;
1958 	vm_offset_t addr, zkva;
1959 	int cpu, flags;
1960 	vm_page_t p, p_next;
1961 #ifdef NUMA
1962 	struct pcpu *pc;
1963 #endif
1964 
1965 	MPASS(bytes == (mp_maxid + 1) * PAGE_SIZE);
1966 
1967 	TAILQ_INIT(&alloctail);
1968 	flags = VM_ALLOC_SYSTEM | VM_ALLOC_WIRED | malloc2vm_flags(wait);
1969 	*pflag = UMA_SLAB_KERNEL;
1970 	for (cpu = 0; cpu <= mp_maxid; cpu++) {
1971 		if (CPU_ABSENT(cpu)) {
1972 			p = vm_page_alloc_noobj(flags);
1973 		} else {
1974 #ifndef NUMA
1975 			p = vm_page_alloc_noobj(flags);
1976 #else
1977 			pc = pcpu_find(cpu);
1978 			if (__predict_false(VM_DOMAIN_EMPTY(pc->pc_domain)))
1979 				p = NULL;
1980 			else
1981 				p = vm_page_alloc_noobj_domain(pc->pc_domain,
1982 				    flags);
1983 			if (__predict_false(p == NULL))
1984 				p = vm_page_alloc_noobj(flags);
1985 #endif
1986 		}
1987 		if (__predict_false(p == NULL))
1988 			goto fail;
1989 		TAILQ_INSERT_TAIL(&alloctail, p, listq);
1990 	}
1991 	if ((addr = kva_alloc(bytes)) == 0)
1992 		goto fail;
1993 	zkva = addr;
1994 	TAILQ_FOREACH(p, &alloctail, listq) {
1995 		pmap_qenter(zkva, &p, 1);
1996 		zkva += PAGE_SIZE;
1997 	}
1998 	return ((void*)addr);
1999 fail:
2000 	TAILQ_FOREACH_SAFE(p, &alloctail, listq, p_next) {
2001 		vm_page_unwire_noq(p);
2002 		vm_page_free(p);
2003 	}
2004 	return (NULL);
2005 }
2006 
2007 /*
2008  * Allocates a number of pages not belonging to a VM object
2009  *
2010  * Arguments:
2011  *	bytes  The number of bytes requested
2012  *	wait   Shall we wait?
2013  *
2014  * Returns:
2015  *	A pointer to the alloced memory or possibly
2016  *	NULL if M_NOWAIT is set.
2017  */
2018 static void *
2019 noobj_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *flags,
2020     int wait)
2021 {
2022 	TAILQ_HEAD(, vm_page) alloctail;
2023 	u_long npages;
2024 	vm_offset_t retkva, zkva;
2025 	vm_page_t p, p_next;
2026 	uma_keg_t keg;
2027 	int req;
2028 
2029 	TAILQ_INIT(&alloctail);
2030 	keg = zone->uz_keg;
2031 	req = VM_ALLOC_INTERRUPT | VM_ALLOC_WIRED;
2032 	if ((wait & M_WAITOK) != 0)
2033 		req |= VM_ALLOC_WAITOK;
2034 
2035 	npages = howmany(bytes, PAGE_SIZE);
2036 	while (npages > 0) {
2037 		p = vm_page_alloc_noobj_domain(domain, req);
2038 		if (p != NULL) {
2039 			/*
2040 			 * Since the page does not belong to an object, its
2041 			 * listq is unused.
2042 			 */
2043 			TAILQ_INSERT_TAIL(&alloctail, p, listq);
2044 			npages--;
2045 			continue;
2046 		}
2047 		/*
2048 		 * Page allocation failed, free intermediate pages and
2049 		 * exit.
2050 		 */
2051 		TAILQ_FOREACH_SAFE(p, &alloctail, listq, p_next) {
2052 			vm_page_unwire_noq(p);
2053 			vm_page_free(p);
2054 		}
2055 		return (NULL);
2056 	}
2057 	*flags = UMA_SLAB_PRIV;
2058 	zkva = keg->uk_kva +
2059 	    atomic_fetchadd_long(&keg->uk_offset, round_page(bytes));
2060 	retkva = zkva;
2061 	TAILQ_FOREACH(p, &alloctail, listq) {
2062 		pmap_qenter(zkva, &p, 1);
2063 		zkva += PAGE_SIZE;
2064 	}
2065 
2066 	return ((void *)retkva);
2067 }
2068 
2069 /*
2070  * Allocate physically contiguous pages.
2071  */
2072 static void *
2073 contig_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
2074     int wait)
2075 {
2076 
2077 	*pflag = UMA_SLAB_KERNEL;
2078 	return ((void *)kmem_alloc_contig_domainset(DOMAINSET_FIXED(domain),
2079 	    bytes, wait, 0, ~(vm_paddr_t)0, 1, 0, VM_MEMATTR_DEFAULT));
2080 }
2081 
2082 /*
2083  * Frees a number of pages to the system
2084  *
2085  * Arguments:
2086  *	mem   A pointer to the memory to be freed
2087  *	size  The size of the memory being freed
2088  *	flags The original p->us_flags field
2089  *
2090  * Returns:
2091  *	Nothing
2092  */
2093 static void
2094 page_free(void *mem, vm_size_t size, uint8_t flags)
2095 {
2096 
2097 	if ((flags & UMA_SLAB_BOOT) != 0) {
2098 		startup_free(mem, size);
2099 		return;
2100 	}
2101 
2102 	KASSERT((flags & UMA_SLAB_KERNEL) != 0,
2103 	    ("UMA: page_free used with invalid flags %x", flags));
2104 
2105 	kmem_free(mem, size);
2106 }
2107 
2108 /*
2109  * Frees pcpu zone allocations
2110  *
2111  * Arguments:
2112  *	mem   A pointer to the memory to be freed
2113  *	size  The size of the memory being freed
2114  *	flags The original p->us_flags field
2115  *
2116  * Returns:
2117  *	Nothing
2118  */
2119 static void
2120 pcpu_page_free(void *mem, vm_size_t size, uint8_t flags)
2121 {
2122 	vm_offset_t sva, curva;
2123 	vm_paddr_t paddr;
2124 	vm_page_t m;
2125 
2126 	MPASS(size == (mp_maxid+1)*PAGE_SIZE);
2127 
2128 	if ((flags & UMA_SLAB_BOOT) != 0) {
2129 		startup_free(mem, size);
2130 		return;
2131 	}
2132 
2133 	sva = (vm_offset_t)mem;
2134 	for (curva = sva; curva < sva + size; curva += PAGE_SIZE) {
2135 		paddr = pmap_kextract(curva);
2136 		m = PHYS_TO_VM_PAGE(paddr);
2137 		vm_page_unwire_noq(m);
2138 		vm_page_free(m);
2139 	}
2140 	pmap_qremove(sva, size >> PAGE_SHIFT);
2141 	kva_free(sva, size);
2142 }
2143 
2144 /*
2145  * Zero fill initializer
2146  *
2147  * Arguments/Returns follow uma_init specifications
2148  */
2149 static int
2150 zero_init(void *mem, int size, int flags)
2151 {
2152 	bzero(mem, size);
2153 	return (0);
2154 }
2155 
2156 #ifdef INVARIANTS
2157 static struct noslabbits *
2158 slab_dbg_bits(uma_slab_t slab, uma_keg_t keg)
2159 {
2160 
2161 	return ((void *)((char *)&slab->us_free + BITSET_SIZE(keg->uk_ipers)));
2162 }
2163 #endif
2164 
2165 /*
2166  * Actual size of embedded struct slab (!OFFPAGE).
2167  */
2168 static size_t
2169 slab_sizeof(int nitems)
2170 {
2171 	size_t s;
2172 
2173 	s = sizeof(struct uma_slab) + BITSET_SIZE(nitems) * SLAB_BITSETS;
2174 	return (roundup(s, UMA_ALIGN_PTR + 1));
2175 }
2176 
2177 #define	UMA_FIXPT_SHIFT	31
2178 #define	UMA_FRAC_FIXPT(n, d)						\
2179 	((uint32_t)(((uint64_t)(n) << UMA_FIXPT_SHIFT) / (d)))
2180 #define	UMA_FIXPT_PCT(f)						\
2181 	((u_int)(((uint64_t)100 * (f)) >> UMA_FIXPT_SHIFT))
2182 #define	UMA_PCT_FIXPT(pct)	UMA_FRAC_FIXPT((pct), 100)
2183 #define	UMA_MIN_EFF	UMA_PCT_FIXPT(100 - UMA_MAX_WASTE)
2184 
2185 /*
2186  * Compute the number of items that will fit in a slab.  If hdr is true, the
2187  * item count may be limited to provide space in the slab for an inline slab
2188  * header.  Otherwise, all slab space will be provided for item storage.
2189  */
2190 static u_int
2191 slab_ipers_hdr(u_int size, u_int rsize, u_int slabsize, bool hdr)
2192 {
2193 	u_int ipers;
2194 	u_int padpi;
2195 
2196 	/* The padding between items is not needed after the last item. */
2197 	padpi = rsize - size;
2198 
2199 	if (hdr) {
2200 		/*
2201 		 * Start with the maximum item count and remove items until
2202 		 * the slab header first alongside the allocatable memory.
2203 		 */
2204 		for (ipers = MIN(SLAB_MAX_SETSIZE,
2205 		    (slabsize + padpi - slab_sizeof(1)) / rsize);
2206 		    ipers > 0 &&
2207 		    ipers * rsize - padpi + slab_sizeof(ipers) > slabsize;
2208 		    ipers--)
2209 			continue;
2210 	} else {
2211 		ipers = MIN((slabsize + padpi) / rsize, SLAB_MAX_SETSIZE);
2212 	}
2213 
2214 	return (ipers);
2215 }
2216 
2217 struct keg_layout_result {
2218 	u_int format;
2219 	u_int slabsize;
2220 	u_int ipers;
2221 	u_int eff;
2222 };
2223 
2224 static void
2225 keg_layout_one(uma_keg_t keg, u_int rsize, u_int slabsize, u_int fmt,
2226     struct keg_layout_result *kl)
2227 {
2228 	u_int total;
2229 
2230 	kl->format = fmt;
2231 	kl->slabsize = slabsize;
2232 
2233 	/* Handle INTERNAL as inline with an extra page. */
2234 	if ((fmt & UMA_ZFLAG_INTERNAL) != 0) {
2235 		kl->format &= ~UMA_ZFLAG_INTERNAL;
2236 		kl->slabsize += PAGE_SIZE;
2237 	}
2238 
2239 	kl->ipers = slab_ipers_hdr(keg->uk_size, rsize, kl->slabsize,
2240 	    (fmt & UMA_ZFLAG_OFFPAGE) == 0);
2241 
2242 	/* Account for memory used by an offpage slab header. */
2243 	total = kl->slabsize;
2244 	if ((fmt & UMA_ZFLAG_OFFPAGE) != 0)
2245 		total += slabzone(kl->ipers)->uz_keg->uk_rsize;
2246 
2247 	kl->eff = UMA_FRAC_FIXPT(kl->ipers * rsize, total);
2248 }
2249 
2250 /*
2251  * Determine the format of a uma keg.  This determines where the slab header
2252  * will be placed (inline or offpage) and calculates ipers, rsize, and ppera.
2253  *
2254  * Arguments
2255  *	keg  The zone we should initialize
2256  *
2257  * Returns
2258  *	Nothing
2259  */
2260 static void
2261 keg_layout(uma_keg_t keg)
2262 {
2263 	struct keg_layout_result kl = {}, kl_tmp;
2264 	u_int fmts[2];
2265 	u_int alignsize;
2266 	u_int nfmt;
2267 	u_int pages;
2268 	u_int rsize;
2269 	u_int slabsize;
2270 	u_int i, j;
2271 
2272 	KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0 ||
2273 	    (keg->uk_size <= UMA_PCPU_ALLOC_SIZE &&
2274 	     (keg->uk_flags & UMA_ZONE_CACHESPREAD) == 0),
2275 	    ("%s: cannot configure for PCPU: keg=%s, size=%u, flags=0x%b",
2276 	     __func__, keg->uk_name, keg->uk_size, keg->uk_flags,
2277 	     PRINT_UMA_ZFLAGS));
2278 	KASSERT((keg->uk_flags & (UMA_ZFLAG_INTERNAL | UMA_ZONE_VM)) == 0 ||
2279 	    (keg->uk_flags & (UMA_ZONE_NOTOUCH | UMA_ZONE_PCPU)) == 0,
2280 	    ("%s: incompatible flags 0x%b", __func__, keg->uk_flags,
2281 	     PRINT_UMA_ZFLAGS));
2282 
2283 	alignsize = keg->uk_align + 1;
2284 #ifdef KASAN
2285 	/*
2286 	 * ASAN requires that each allocation be aligned to the shadow map
2287 	 * scale factor.
2288 	 */
2289 	if (alignsize < KASAN_SHADOW_SCALE)
2290 		alignsize = KASAN_SHADOW_SCALE;
2291 #endif
2292 
2293 	/*
2294 	 * Calculate the size of each allocation (rsize) according to
2295 	 * alignment.  If the requested size is smaller than we have
2296 	 * allocation bits for we round it up.
2297 	 */
2298 	rsize = MAX(keg->uk_size, UMA_SMALLEST_UNIT);
2299 	rsize = roundup2(rsize, alignsize);
2300 
2301 	if ((keg->uk_flags & UMA_ZONE_CACHESPREAD) != 0) {
2302 		/*
2303 		 * We want one item to start on every align boundary in a page.
2304 		 * To do this we will span pages.  We will also extend the item
2305 		 * by the size of align if it is an even multiple of align.
2306 		 * Otherwise, it would fall on the same boundary every time.
2307 		 */
2308 		if ((rsize & alignsize) == 0)
2309 			rsize += alignsize;
2310 		slabsize = rsize * (PAGE_SIZE / alignsize);
2311 		slabsize = MIN(slabsize, rsize * SLAB_MAX_SETSIZE);
2312 		slabsize = MIN(slabsize, UMA_CACHESPREAD_MAX_SIZE);
2313 		slabsize = round_page(slabsize);
2314 	} else {
2315 		/*
2316 		 * Start with a slab size of as many pages as it takes to
2317 		 * represent a single item.  We will try to fit as many
2318 		 * additional items into the slab as possible.
2319 		 */
2320 		slabsize = round_page(keg->uk_size);
2321 	}
2322 
2323 	/* Build a list of all of the available formats for this keg. */
2324 	nfmt = 0;
2325 
2326 	/* Evaluate an inline slab layout. */
2327 	if ((keg->uk_flags & (UMA_ZONE_NOTOUCH | UMA_ZONE_PCPU)) == 0)
2328 		fmts[nfmt++] = 0;
2329 
2330 	/* TODO: vm_page-embedded slab. */
2331 
2332 	/*
2333 	 * We can't do OFFPAGE if we're internal or if we've been
2334 	 * asked to not go to the VM for buckets.  If we do this we
2335 	 * may end up going to the VM for slabs which we do not want
2336 	 * to do if we're UMA_ZONE_VM, which clearly forbids it.
2337 	 * In those cases, evaluate a pseudo-format called INTERNAL
2338 	 * which has an inline slab header and one extra page to
2339 	 * guarantee that it fits.
2340 	 *
2341 	 * Otherwise, see if using an OFFPAGE slab will improve our
2342 	 * efficiency.
2343 	 */
2344 	if ((keg->uk_flags & (UMA_ZFLAG_INTERNAL | UMA_ZONE_VM)) != 0)
2345 		fmts[nfmt++] = UMA_ZFLAG_INTERNAL;
2346 	else
2347 		fmts[nfmt++] = UMA_ZFLAG_OFFPAGE;
2348 
2349 	/*
2350 	 * Choose a slab size and format which satisfy the minimum efficiency.
2351 	 * Prefer the smallest slab size that meets the constraints.
2352 	 *
2353 	 * Start with a minimum slab size, to accommodate CACHESPREAD.  Then,
2354 	 * for small items (up to PAGE_SIZE), the iteration increment is one
2355 	 * page; and for large items, the increment is one item.
2356 	 */
2357 	i = (slabsize + rsize - keg->uk_size) / MAX(PAGE_SIZE, rsize);
2358 	KASSERT(i >= 1, ("keg %s(%p) flags=0x%b slabsize=%u, rsize=%u, i=%u",
2359 	    keg->uk_name, keg, keg->uk_flags, PRINT_UMA_ZFLAGS, slabsize,
2360 	    rsize, i));
2361 	for ( ; ; i++) {
2362 		slabsize = (rsize <= PAGE_SIZE) ? ptoa(i) :
2363 		    round_page(rsize * (i - 1) + keg->uk_size);
2364 
2365 		for (j = 0; j < nfmt; j++) {
2366 			/* Only if we have no viable format yet. */
2367 			if ((fmts[j] & UMA_ZFLAG_INTERNAL) != 0 &&
2368 			    kl.ipers > 0)
2369 				continue;
2370 
2371 			keg_layout_one(keg, rsize, slabsize, fmts[j], &kl_tmp);
2372 			if (kl_tmp.eff <= kl.eff)
2373 				continue;
2374 
2375 			kl = kl_tmp;
2376 
2377 			CTR6(KTR_UMA, "keg %s layout: format %#x "
2378 			    "(ipers %u * rsize %u) / slabsize %#x = %u%% eff",
2379 			    keg->uk_name, kl.format, kl.ipers, rsize,
2380 			    kl.slabsize, UMA_FIXPT_PCT(kl.eff));
2381 
2382 			/* Stop when we reach the minimum efficiency. */
2383 			if (kl.eff >= UMA_MIN_EFF)
2384 				break;
2385 		}
2386 
2387 		if (kl.eff >= UMA_MIN_EFF || !multipage_slabs ||
2388 		    slabsize >= SLAB_MAX_SETSIZE * rsize ||
2389 		    (keg->uk_flags & (UMA_ZONE_PCPU | UMA_ZONE_CONTIG)) != 0)
2390 			break;
2391 	}
2392 
2393 	pages = atop(kl.slabsize);
2394 	if ((keg->uk_flags & UMA_ZONE_PCPU) != 0)
2395 		pages *= mp_maxid + 1;
2396 
2397 	keg->uk_rsize = rsize;
2398 	keg->uk_ipers = kl.ipers;
2399 	keg->uk_ppera = pages;
2400 	keg->uk_flags |= kl.format;
2401 
2402 	/*
2403 	 * How do we find the slab header if it is offpage or if not all item
2404 	 * start addresses are in the same page?  We could solve the latter
2405 	 * case with vaddr alignment, but we don't.
2406 	 */
2407 	if ((keg->uk_flags & UMA_ZFLAG_OFFPAGE) != 0 ||
2408 	    (keg->uk_ipers - 1) * rsize >= PAGE_SIZE) {
2409 		if ((keg->uk_flags & UMA_ZONE_NOTPAGE) != 0)
2410 			keg->uk_flags |= UMA_ZFLAG_HASH;
2411 		else
2412 			keg->uk_flags |= UMA_ZFLAG_VTOSLAB;
2413 	}
2414 
2415 	CTR6(KTR_UMA, "%s: keg=%s, flags=%#x, rsize=%u, ipers=%u, ppera=%u",
2416 	    __func__, keg->uk_name, keg->uk_flags, rsize, keg->uk_ipers,
2417 	    pages);
2418 	KASSERT(keg->uk_ipers > 0 && keg->uk_ipers <= SLAB_MAX_SETSIZE,
2419 	    ("%s: keg=%s, flags=0x%b, rsize=%u, ipers=%u, ppera=%u", __func__,
2420 	     keg->uk_name, keg->uk_flags, PRINT_UMA_ZFLAGS, rsize,
2421 	     keg->uk_ipers, pages));
2422 }
2423 
2424 /*
2425  * Keg header ctor.  This initializes all fields, locks, etc.  And inserts
2426  * the keg onto the global keg list.
2427  *
2428  * Arguments/Returns follow uma_ctor specifications
2429  *	udata  Actually uma_kctor_args
2430  */
2431 static int
2432 keg_ctor(void *mem, int size, void *udata, int flags)
2433 {
2434 	struct uma_kctor_args *arg = udata;
2435 	uma_keg_t keg = mem;
2436 	uma_zone_t zone;
2437 	int i;
2438 
2439 	bzero(keg, size);
2440 	keg->uk_size = arg->size;
2441 	keg->uk_init = arg->uminit;
2442 	keg->uk_fini = arg->fini;
2443 	keg->uk_align = arg->align;
2444 	keg->uk_reserve = 0;
2445 	keg->uk_flags = arg->flags;
2446 
2447 	/*
2448 	 * We use a global round-robin policy by default.  Zones with
2449 	 * UMA_ZONE_FIRSTTOUCH set will use first-touch instead, in which
2450 	 * case the iterator is never run.
2451 	 */
2452 	keg->uk_dr.dr_policy = DOMAINSET_RR();
2453 	keg->uk_dr.dr_iter = 0;
2454 
2455 	/*
2456 	 * The primary zone is passed to us at keg-creation time.
2457 	 */
2458 	zone = arg->zone;
2459 	keg->uk_name = zone->uz_name;
2460 
2461 	if (arg->flags & UMA_ZONE_ZINIT)
2462 		keg->uk_init = zero_init;
2463 
2464 	if (arg->flags & UMA_ZONE_MALLOC)
2465 		keg->uk_flags |= UMA_ZFLAG_VTOSLAB;
2466 
2467 #ifndef SMP
2468 	keg->uk_flags &= ~UMA_ZONE_PCPU;
2469 #endif
2470 
2471 	keg_layout(keg);
2472 
2473 	/*
2474 	 * Use a first-touch NUMA policy for kegs that pmap_extract() will
2475 	 * work on.  Use round-robin for everything else.
2476 	 *
2477 	 * Zones may override the default by specifying either.
2478 	 */
2479 #ifdef NUMA
2480 	if ((keg->uk_flags &
2481 	    (UMA_ZONE_ROUNDROBIN | UMA_ZFLAG_CACHE | UMA_ZONE_NOTPAGE)) == 0)
2482 		keg->uk_flags |= UMA_ZONE_FIRSTTOUCH;
2483 	else if ((keg->uk_flags & UMA_ZONE_FIRSTTOUCH) == 0)
2484 		keg->uk_flags |= UMA_ZONE_ROUNDROBIN;
2485 #endif
2486 
2487 	/*
2488 	 * If we haven't booted yet we need allocations to go through the
2489 	 * startup cache until the vm is ready.
2490 	 */
2491 #ifdef UMA_MD_SMALL_ALLOC
2492 	if (keg->uk_ppera == 1)
2493 		keg->uk_allocf = uma_small_alloc;
2494 	else
2495 #endif
2496 	if (booted < BOOT_KVA)
2497 		keg->uk_allocf = startup_alloc;
2498 	else if (keg->uk_flags & UMA_ZONE_PCPU)
2499 		keg->uk_allocf = pcpu_page_alloc;
2500 	else if ((keg->uk_flags & UMA_ZONE_CONTIG) != 0 && keg->uk_ppera > 1)
2501 		keg->uk_allocf = contig_alloc;
2502 	else
2503 		keg->uk_allocf = page_alloc;
2504 #ifdef UMA_MD_SMALL_ALLOC
2505 	if (keg->uk_ppera == 1)
2506 		keg->uk_freef = uma_small_free;
2507 	else
2508 #endif
2509 	if (keg->uk_flags & UMA_ZONE_PCPU)
2510 		keg->uk_freef = pcpu_page_free;
2511 	else
2512 		keg->uk_freef = page_free;
2513 
2514 	/*
2515 	 * Initialize keg's locks.
2516 	 */
2517 	for (i = 0; i < vm_ndomains; i++)
2518 		KEG_LOCK_INIT(keg, i, (arg->flags & UMA_ZONE_MTXCLASS));
2519 
2520 	/*
2521 	 * If we're putting the slab header in the actual page we need to
2522 	 * figure out where in each page it goes.  See slab_sizeof
2523 	 * definition.
2524 	 */
2525 	if (!(keg->uk_flags & UMA_ZFLAG_OFFPAGE)) {
2526 		size_t shsize;
2527 
2528 		shsize = slab_sizeof(keg->uk_ipers);
2529 		keg->uk_pgoff = (PAGE_SIZE * keg->uk_ppera) - shsize;
2530 		/*
2531 		 * The only way the following is possible is if with our
2532 		 * UMA_ALIGN_PTR adjustments we are now bigger than
2533 		 * UMA_SLAB_SIZE.  I haven't checked whether this is
2534 		 * mathematically possible for all cases, so we make
2535 		 * sure here anyway.
2536 		 */
2537 		KASSERT(keg->uk_pgoff + shsize <= PAGE_SIZE * keg->uk_ppera,
2538 		    ("zone %s ipers %d rsize %d size %d slab won't fit",
2539 		    zone->uz_name, keg->uk_ipers, keg->uk_rsize, keg->uk_size));
2540 	}
2541 
2542 	if (keg->uk_flags & UMA_ZFLAG_HASH)
2543 		hash_alloc(&keg->uk_hash, 0);
2544 
2545 	CTR3(KTR_UMA, "keg_ctor %p zone %s(%p)", keg, zone->uz_name, zone);
2546 
2547 	LIST_INSERT_HEAD(&keg->uk_zones, zone, uz_link);
2548 
2549 	rw_wlock(&uma_rwlock);
2550 	LIST_INSERT_HEAD(&uma_kegs, keg, uk_link);
2551 	rw_wunlock(&uma_rwlock);
2552 	return (0);
2553 }
2554 
2555 static void
2556 zone_kva_available(uma_zone_t zone, void *unused)
2557 {
2558 	uma_keg_t keg;
2559 
2560 	if ((zone->uz_flags & UMA_ZFLAG_CACHE) != 0)
2561 		return;
2562 	KEG_GET(zone, keg);
2563 
2564 	if (keg->uk_allocf == startup_alloc) {
2565 		/* Switch to the real allocator. */
2566 		if (keg->uk_flags & UMA_ZONE_PCPU)
2567 			keg->uk_allocf = pcpu_page_alloc;
2568 		else if ((keg->uk_flags & UMA_ZONE_CONTIG) != 0 &&
2569 		    keg->uk_ppera > 1)
2570 			keg->uk_allocf = contig_alloc;
2571 		else
2572 			keg->uk_allocf = page_alloc;
2573 	}
2574 }
2575 
2576 static void
2577 zone_alloc_counters(uma_zone_t zone, void *unused)
2578 {
2579 
2580 	zone->uz_allocs = counter_u64_alloc(M_WAITOK);
2581 	zone->uz_frees = counter_u64_alloc(M_WAITOK);
2582 	zone->uz_fails = counter_u64_alloc(M_WAITOK);
2583 	zone->uz_xdomain = counter_u64_alloc(M_WAITOK);
2584 }
2585 
2586 static void
2587 zone_alloc_sysctl(uma_zone_t zone, void *unused)
2588 {
2589 	uma_zone_domain_t zdom;
2590 	uma_domain_t dom;
2591 	uma_keg_t keg;
2592 	struct sysctl_oid *oid, *domainoid;
2593 	int domains, i, cnt;
2594 	static const char *nokeg = "cache zone";
2595 	char *c;
2596 
2597 	/*
2598 	 * Make a sysctl safe copy of the zone name by removing
2599 	 * any special characters and handling dups by appending
2600 	 * an index.
2601 	 */
2602 	if (zone->uz_namecnt != 0) {
2603 		/* Count the number of decimal digits and '_' separator. */
2604 		for (i = 1, cnt = zone->uz_namecnt; cnt != 0; i++)
2605 			cnt /= 10;
2606 		zone->uz_ctlname = malloc(strlen(zone->uz_name) + i + 1,
2607 		    M_UMA, M_WAITOK);
2608 		sprintf(zone->uz_ctlname, "%s_%d", zone->uz_name,
2609 		    zone->uz_namecnt);
2610 	} else
2611 		zone->uz_ctlname = strdup(zone->uz_name, M_UMA);
2612 	for (c = zone->uz_ctlname; *c != '\0'; c++)
2613 		if (strchr("./\\ -", *c) != NULL)
2614 			*c = '_';
2615 
2616 	/*
2617 	 * Basic parameters at the root.
2618 	 */
2619 	zone->uz_oid = SYSCTL_ADD_NODE(NULL, SYSCTL_STATIC_CHILDREN(_vm_uma),
2620 	    OID_AUTO, zone->uz_ctlname, CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
2621 	oid = zone->uz_oid;
2622 	SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2623 	    "size", CTLFLAG_RD, &zone->uz_size, 0, "Allocation size");
2624 	SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2625 	    "flags", CTLFLAG_RD | CTLTYPE_STRING | CTLFLAG_MPSAFE,
2626 	    zone, 0, sysctl_handle_uma_zone_flags, "A",
2627 	    "Allocator configuration flags");
2628 	SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2629 	    "bucket_size", CTLFLAG_RD, &zone->uz_bucket_size, 0,
2630 	    "Desired per-cpu cache size");
2631 	SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2632 	    "bucket_size_max", CTLFLAG_RD, &zone->uz_bucket_size_max, 0,
2633 	    "Maximum allowed per-cpu cache size");
2634 
2635 	/*
2636 	 * keg if present.
2637 	 */
2638 	if ((zone->uz_flags & UMA_ZFLAG_HASH) == 0)
2639 		domains = vm_ndomains;
2640 	else
2641 		domains = 1;
2642 	oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid), OID_AUTO,
2643 	    "keg", CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
2644 	keg = zone->uz_keg;
2645 	if ((zone->uz_flags & UMA_ZFLAG_CACHE) == 0) {
2646 		SYSCTL_ADD_CONST_STRING(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2647 		    "name", CTLFLAG_RD, keg->uk_name, "Keg name");
2648 		SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2649 		    "rsize", CTLFLAG_RD, &keg->uk_rsize, 0,
2650 		    "Real object size with alignment");
2651 		SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2652 		    "ppera", CTLFLAG_RD, &keg->uk_ppera, 0,
2653 		    "pages per-slab allocation");
2654 		SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2655 		    "ipers", CTLFLAG_RD, &keg->uk_ipers, 0,
2656 		    "items available per-slab");
2657 		SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2658 		    "align", CTLFLAG_RD, &keg->uk_align, 0,
2659 		    "item alignment mask");
2660 		SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2661 		    "reserve", CTLFLAG_RD, &keg->uk_reserve, 0,
2662 		    "number of reserved items");
2663 		SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2664 		    "efficiency", CTLFLAG_RD | CTLTYPE_INT | CTLFLAG_MPSAFE,
2665 		    keg, 0, sysctl_handle_uma_slab_efficiency, "I",
2666 		    "Slab utilization (100 - internal fragmentation %)");
2667 		domainoid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(oid),
2668 		    OID_AUTO, "domain", CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
2669 		for (i = 0; i < domains; i++) {
2670 			dom = &keg->uk_domain[i];
2671 			oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(domainoid),
2672 			    OID_AUTO, VM_DOMAIN(i)->vmd_name,
2673 			    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
2674 			SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2675 			    "pages", CTLFLAG_RD, &dom->ud_pages, 0,
2676 			    "Total pages currently allocated from VM");
2677 			SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2678 			    "free_items", CTLFLAG_RD, &dom->ud_free_items, 0,
2679 			    "Items free in the slab layer");
2680 			SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2681 			    "free_slabs", CTLFLAG_RD, &dom->ud_free_slabs, 0,
2682 			    "Unused slabs");
2683 		}
2684 	} else
2685 		SYSCTL_ADD_CONST_STRING(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2686 		    "name", CTLFLAG_RD, nokeg, "Keg name");
2687 
2688 	/*
2689 	 * Information about zone limits.
2690 	 */
2691 	oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid), OID_AUTO,
2692 	    "limit", CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
2693 	SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2694 	    "items", CTLFLAG_RD | CTLTYPE_U64 | CTLFLAG_MPSAFE,
2695 	    zone, 0, sysctl_handle_uma_zone_items, "QU",
2696 	    "Current number of allocated items if limit is set");
2697 	SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2698 	    "max_items", CTLFLAG_RD, &zone->uz_max_items, 0,
2699 	    "Maximum number of allocated and cached items");
2700 	SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2701 	    "sleepers", CTLFLAG_RD, &zone->uz_sleepers, 0,
2702 	    "Number of threads sleeping at limit");
2703 	SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2704 	    "sleeps", CTLFLAG_RD, &zone->uz_sleeps, 0,
2705 	    "Total zone limit sleeps");
2706 	SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2707 	    "bucket_max", CTLFLAG_RD, &zone->uz_bucket_max, 0,
2708 	    "Maximum number of items in each domain's bucket cache");
2709 
2710 	/*
2711 	 * Per-domain zone information.
2712 	 */
2713 	domainoid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid),
2714 	    OID_AUTO, "domain", CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
2715 	for (i = 0; i < domains; i++) {
2716 		zdom = ZDOM_GET(zone, i);
2717 		oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(domainoid),
2718 		    OID_AUTO, VM_DOMAIN(i)->vmd_name,
2719 		    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
2720 		SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2721 		    "nitems", CTLFLAG_RD, &zdom->uzd_nitems,
2722 		    "number of items in this domain");
2723 		SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2724 		    "imax", CTLFLAG_RD, &zdom->uzd_imax,
2725 		    "maximum item count in this period");
2726 		SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2727 		    "imin", CTLFLAG_RD, &zdom->uzd_imin,
2728 		    "minimum item count in this period");
2729 		SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2730 		    "bimin", CTLFLAG_RD, &zdom->uzd_bimin,
2731 		    "Minimum item count in this batch");
2732 		SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2733 		    "wss", CTLFLAG_RD, &zdom->uzd_wss,
2734 		    "Working set size");
2735 		SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2736 		    "limin", CTLFLAG_RD, &zdom->uzd_limin,
2737 		    "Long time minimum item count");
2738 		SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2739 		    "timin", CTLFLAG_RD, &zdom->uzd_timin, 0,
2740 		    "Time since zero long time minimum item count");
2741 	}
2742 
2743 	/*
2744 	 * General statistics.
2745 	 */
2746 	oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid), OID_AUTO,
2747 	    "stats", CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
2748 	SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2749 	    "current", CTLFLAG_RD | CTLTYPE_INT | CTLFLAG_MPSAFE,
2750 	    zone, 1, sysctl_handle_uma_zone_cur, "I",
2751 	    "Current number of allocated items");
2752 	SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2753 	    "allocs", CTLFLAG_RD | CTLTYPE_U64 | CTLFLAG_MPSAFE,
2754 	    zone, 0, sysctl_handle_uma_zone_allocs, "QU",
2755 	    "Total allocation calls");
2756 	SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2757 	    "frees", CTLFLAG_RD | CTLTYPE_U64 | CTLFLAG_MPSAFE,
2758 	    zone, 0, sysctl_handle_uma_zone_frees, "QU",
2759 	    "Total free calls");
2760 	SYSCTL_ADD_COUNTER_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2761 	    "fails", CTLFLAG_RD, &zone->uz_fails,
2762 	    "Number of allocation failures");
2763 	SYSCTL_ADD_COUNTER_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2764 	    "xdomain", CTLFLAG_RD, &zone->uz_xdomain,
2765 	    "Free calls from the wrong domain");
2766 }
2767 
2768 struct uma_zone_count {
2769 	const char	*name;
2770 	int		count;
2771 };
2772 
2773 static void
2774 zone_count(uma_zone_t zone, void *arg)
2775 {
2776 	struct uma_zone_count *cnt;
2777 
2778 	cnt = arg;
2779 	/*
2780 	 * Some zones are rapidly created with identical names and
2781 	 * destroyed out of order.  This can lead to gaps in the count.
2782 	 * Use one greater than the maximum observed for this name.
2783 	 */
2784 	if (strcmp(zone->uz_name, cnt->name) == 0)
2785 		cnt->count = MAX(cnt->count,
2786 		    zone->uz_namecnt + 1);
2787 }
2788 
2789 static void
2790 zone_update_caches(uma_zone_t zone)
2791 {
2792 	int i;
2793 
2794 	for (i = 0; i <= mp_maxid; i++) {
2795 		cache_set_uz_size(&zone->uz_cpu[i], zone->uz_size);
2796 		cache_set_uz_flags(&zone->uz_cpu[i], zone->uz_flags);
2797 	}
2798 }
2799 
2800 /*
2801  * Zone header ctor.  This initializes all fields, locks, etc.
2802  *
2803  * Arguments/Returns follow uma_ctor specifications
2804  *	udata  Actually uma_zctor_args
2805  */
2806 static int
2807 zone_ctor(void *mem, int size, void *udata, int flags)
2808 {
2809 	struct uma_zone_count cnt;
2810 	struct uma_zctor_args *arg = udata;
2811 	uma_zone_domain_t zdom;
2812 	uma_zone_t zone = mem;
2813 	uma_zone_t z;
2814 	uma_keg_t keg;
2815 	int i;
2816 
2817 	bzero(zone, size);
2818 	zone->uz_name = arg->name;
2819 	zone->uz_ctor = arg->ctor;
2820 	zone->uz_dtor = arg->dtor;
2821 	zone->uz_init = NULL;
2822 	zone->uz_fini = NULL;
2823 	zone->uz_sleeps = 0;
2824 	zone->uz_bucket_size = 0;
2825 	zone->uz_bucket_size_min = 0;
2826 	zone->uz_bucket_size_max = BUCKET_MAX;
2827 	zone->uz_flags = (arg->flags & UMA_ZONE_SMR);
2828 	zone->uz_warning = NULL;
2829 	/* The domain structures follow the cpu structures. */
2830 	zone->uz_bucket_max = ULONG_MAX;
2831 	timevalclear(&zone->uz_ratecheck);
2832 
2833 	/* Count the number of duplicate names. */
2834 	cnt.name = arg->name;
2835 	cnt.count = 0;
2836 	zone_foreach(zone_count, &cnt);
2837 	zone->uz_namecnt = cnt.count;
2838 	ZONE_CROSS_LOCK_INIT(zone);
2839 
2840 	for (i = 0; i < vm_ndomains; i++) {
2841 		zdom = ZDOM_GET(zone, i);
2842 		ZDOM_LOCK_INIT(zone, zdom, (arg->flags & UMA_ZONE_MTXCLASS));
2843 		STAILQ_INIT(&zdom->uzd_buckets);
2844 	}
2845 
2846 #if defined(INVARIANTS) && !defined(KASAN) && !defined(KMSAN)
2847 	if (arg->uminit == trash_init && arg->fini == trash_fini)
2848 		zone->uz_flags |= UMA_ZFLAG_TRASH | UMA_ZFLAG_CTORDTOR;
2849 #elif defined(KASAN)
2850 	if ((arg->flags & (UMA_ZONE_NOFREE | UMA_ZFLAG_CACHE)) != 0)
2851 		arg->flags |= UMA_ZONE_NOKASAN;
2852 #endif
2853 
2854 	/*
2855 	 * This is a pure cache zone, no kegs.
2856 	 */
2857 	if (arg->import) {
2858 		KASSERT((arg->flags & UMA_ZFLAG_CACHE) != 0,
2859 		    ("zone_ctor: Import specified for non-cache zone."));
2860 		zone->uz_flags = arg->flags;
2861 		zone->uz_size = arg->size;
2862 		zone->uz_import = arg->import;
2863 		zone->uz_release = arg->release;
2864 		zone->uz_arg = arg->arg;
2865 #ifdef NUMA
2866 		/*
2867 		 * Cache zones are round-robin unless a policy is
2868 		 * specified because they may have incompatible
2869 		 * constraints.
2870 		 */
2871 		if ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) == 0)
2872 			zone->uz_flags |= UMA_ZONE_ROUNDROBIN;
2873 #endif
2874 		rw_wlock(&uma_rwlock);
2875 		LIST_INSERT_HEAD(&uma_cachezones, zone, uz_link);
2876 		rw_wunlock(&uma_rwlock);
2877 		goto out;
2878 	}
2879 
2880 	/*
2881 	 * Use the regular zone/keg/slab allocator.
2882 	 */
2883 	zone->uz_import = zone_import;
2884 	zone->uz_release = zone_release;
2885 	zone->uz_arg = zone;
2886 	keg = arg->keg;
2887 
2888 	if (arg->flags & UMA_ZONE_SECONDARY) {
2889 		KASSERT((zone->uz_flags & UMA_ZONE_SECONDARY) == 0,
2890 		    ("Secondary zone requested UMA_ZFLAG_INTERNAL"));
2891 		KASSERT(arg->keg != NULL, ("Secondary zone on zero'd keg"));
2892 		zone->uz_init = arg->uminit;
2893 		zone->uz_fini = arg->fini;
2894 		zone->uz_flags |= UMA_ZONE_SECONDARY;
2895 		rw_wlock(&uma_rwlock);
2896 		ZONE_LOCK(zone);
2897 		LIST_FOREACH(z, &keg->uk_zones, uz_link) {
2898 			if (LIST_NEXT(z, uz_link) == NULL) {
2899 				LIST_INSERT_AFTER(z, zone, uz_link);
2900 				break;
2901 			}
2902 		}
2903 		ZONE_UNLOCK(zone);
2904 		rw_wunlock(&uma_rwlock);
2905 	} else if (keg == NULL) {
2906 		if ((keg = uma_kcreate(zone, arg->size, arg->uminit, arg->fini,
2907 		    arg->align, arg->flags)) == NULL)
2908 			return (ENOMEM);
2909 	} else {
2910 		struct uma_kctor_args karg;
2911 		int error;
2912 
2913 		/* We should only be here from uma_startup() */
2914 		karg.size = arg->size;
2915 		karg.uminit = arg->uminit;
2916 		karg.fini = arg->fini;
2917 		karg.align = arg->align;
2918 		karg.flags = (arg->flags & ~UMA_ZONE_SMR);
2919 		karg.zone = zone;
2920 		error = keg_ctor(arg->keg, sizeof(struct uma_keg), &karg,
2921 		    flags);
2922 		if (error)
2923 			return (error);
2924 	}
2925 
2926 	/* Inherit properties from the keg. */
2927 	zone->uz_keg = keg;
2928 	zone->uz_size = keg->uk_size;
2929 	zone->uz_flags |= (keg->uk_flags &
2930 	    (UMA_ZONE_INHERIT | UMA_ZFLAG_INHERIT));
2931 
2932 out:
2933 	if (booted >= BOOT_PCPU) {
2934 		zone_alloc_counters(zone, NULL);
2935 		if (booted >= BOOT_RUNNING)
2936 			zone_alloc_sysctl(zone, NULL);
2937 	} else {
2938 		zone->uz_allocs = EARLY_COUNTER;
2939 		zone->uz_frees = EARLY_COUNTER;
2940 		zone->uz_fails = EARLY_COUNTER;
2941 	}
2942 
2943 	/* Caller requests a private SMR context. */
2944 	if ((zone->uz_flags & UMA_ZONE_SMR) != 0)
2945 		zone->uz_smr = smr_create(zone->uz_name, 0, 0);
2946 
2947 	KASSERT((arg->flags & (UMA_ZONE_MAXBUCKET | UMA_ZONE_NOBUCKET)) !=
2948 	    (UMA_ZONE_MAXBUCKET | UMA_ZONE_NOBUCKET),
2949 	    ("Invalid zone flag combination"));
2950 	if (arg->flags & UMA_ZFLAG_INTERNAL)
2951 		zone->uz_bucket_size_max = zone->uz_bucket_size = 0;
2952 	if ((arg->flags & UMA_ZONE_MAXBUCKET) != 0)
2953 		zone->uz_bucket_size = BUCKET_MAX;
2954 	else if ((arg->flags & UMA_ZONE_NOBUCKET) != 0)
2955 		zone->uz_bucket_size = 0;
2956 	else
2957 		zone->uz_bucket_size = bucket_select(zone->uz_size);
2958 	zone->uz_bucket_size_min = zone->uz_bucket_size;
2959 	if (zone->uz_dtor != NULL || zone->uz_ctor != NULL)
2960 		zone->uz_flags |= UMA_ZFLAG_CTORDTOR;
2961 	zone_update_caches(zone);
2962 
2963 	return (0);
2964 }
2965 
2966 /*
2967  * Keg header dtor.  This frees all data, destroys locks, frees the hash
2968  * table and removes the keg from the global list.
2969  *
2970  * Arguments/Returns follow uma_dtor specifications
2971  *	udata  unused
2972  */
2973 static void
2974 keg_dtor(void *arg, int size, void *udata)
2975 {
2976 	uma_keg_t keg;
2977 	uint32_t free, pages;
2978 	int i;
2979 
2980 	keg = (uma_keg_t)arg;
2981 	free = pages = 0;
2982 	for (i = 0; i < vm_ndomains; i++) {
2983 		free += keg->uk_domain[i].ud_free_items;
2984 		pages += keg->uk_domain[i].ud_pages;
2985 		KEG_LOCK_FINI(keg, i);
2986 	}
2987 	if (pages != 0)
2988 		printf("Freed UMA keg (%s) was not empty (%u items). "
2989 		    " Lost %u pages of memory.\n",
2990 		    keg->uk_name ? keg->uk_name : "",
2991 		    pages / keg->uk_ppera * keg->uk_ipers - free, pages);
2992 
2993 	hash_free(&keg->uk_hash);
2994 }
2995 
2996 /*
2997  * Zone header dtor.
2998  *
2999  * Arguments/Returns follow uma_dtor specifications
3000  *	udata  unused
3001  */
3002 static void
3003 zone_dtor(void *arg, int size, void *udata)
3004 {
3005 	uma_zone_t zone;
3006 	uma_keg_t keg;
3007 	int i;
3008 
3009 	zone = (uma_zone_t)arg;
3010 
3011 	sysctl_remove_oid(zone->uz_oid, 1, 1);
3012 
3013 	if (!(zone->uz_flags & UMA_ZFLAG_INTERNAL))
3014 		cache_drain(zone);
3015 
3016 	rw_wlock(&uma_rwlock);
3017 	LIST_REMOVE(zone, uz_link);
3018 	rw_wunlock(&uma_rwlock);
3019 	if ((zone->uz_flags & (UMA_ZONE_SECONDARY | UMA_ZFLAG_CACHE)) == 0) {
3020 		keg = zone->uz_keg;
3021 		keg->uk_reserve = 0;
3022 	}
3023 	zone_reclaim(zone, UMA_ANYDOMAIN, M_WAITOK, true);
3024 
3025 	/*
3026 	 * We only destroy kegs from non secondary/non cache zones.
3027 	 */
3028 	if ((zone->uz_flags & (UMA_ZONE_SECONDARY | UMA_ZFLAG_CACHE)) == 0) {
3029 		keg = zone->uz_keg;
3030 		rw_wlock(&uma_rwlock);
3031 		LIST_REMOVE(keg, uk_link);
3032 		rw_wunlock(&uma_rwlock);
3033 		zone_free_item(kegs, keg, NULL, SKIP_NONE);
3034 	}
3035 	counter_u64_free(zone->uz_allocs);
3036 	counter_u64_free(zone->uz_frees);
3037 	counter_u64_free(zone->uz_fails);
3038 	counter_u64_free(zone->uz_xdomain);
3039 	free(zone->uz_ctlname, M_UMA);
3040 	for (i = 0; i < vm_ndomains; i++)
3041 		ZDOM_LOCK_FINI(ZDOM_GET(zone, i));
3042 	ZONE_CROSS_LOCK_FINI(zone);
3043 }
3044 
3045 static void
3046 zone_foreach_unlocked(void (*zfunc)(uma_zone_t, void *arg), void *arg)
3047 {
3048 	uma_keg_t keg;
3049 	uma_zone_t zone;
3050 
3051 	LIST_FOREACH(keg, &uma_kegs, uk_link) {
3052 		LIST_FOREACH(zone, &keg->uk_zones, uz_link)
3053 			zfunc(zone, arg);
3054 	}
3055 	LIST_FOREACH(zone, &uma_cachezones, uz_link)
3056 		zfunc(zone, arg);
3057 }
3058 
3059 /*
3060  * Traverses every zone in the system and calls a callback
3061  *
3062  * Arguments:
3063  *	zfunc  A pointer to a function which accepts a zone
3064  *		as an argument.
3065  *
3066  * Returns:
3067  *	Nothing
3068  */
3069 static void
3070 zone_foreach(void (*zfunc)(uma_zone_t, void *arg), void *arg)
3071 {
3072 
3073 	rw_rlock(&uma_rwlock);
3074 	zone_foreach_unlocked(zfunc, arg);
3075 	rw_runlock(&uma_rwlock);
3076 }
3077 
3078 /*
3079  * Initialize the kernel memory allocator.  This is done after pages can be
3080  * allocated but before general KVA is available.
3081  */
3082 void
3083 uma_startup1(vm_offset_t virtual_avail)
3084 {
3085 	struct uma_zctor_args args;
3086 	size_t ksize, zsize, size;
3087 	uma_keg_t primarykeg;
3088 	uintptr_t m;
3089 	int domain;
3090 	uint8_t pflag;
3091 
3092 	bootstart = bootmem = virtual_avail;
3093 
3094 	rw_init(&uma_rwlock, "UMA lock");
3095 	sx_init(&uma_reclaim_lock, "umareclaim");
3096 
3097 	ksize = sizeof(struct uma_keg) +
3098 	    (sizeof(struct uma_domain) * vm_ndomains);
3099 	ksize = roundup(ksize, UMA_SUPER_ALIGN);
3100 	zsize = sizeof(struct uma_zone) +
3101 	    (sizeof(struct uma_cache) * (mp_maxid + 1)) +
3102 	    (sizeof(struct uma_zone_domain) * vm_ndomains);
3103 	zsize = roundup(zsize, UMA_SUPER_ALIGN);
3104 
3105 	/* Allocate the zone of zones, zone of kegs, and zone of zones keg. */
3106 	size = (zsize * 2) + ksize;
3107 	for (domain = 0; domain < vm_ndomains; domain++) {
3108 		m = (uintptr_t)startup_alloc(NULL, size, domain, &pflag,
3109 		    M_NOWAIT | M_ZERO);
3110 		if (m != 0)
3111 			break;
3112 	}
3113 	zones = (uma_zone_t)m;
3114 	m += zsize;
3115 	kegs = (uma_zone_t)m;
3116 	m += zsize;
3117 	primarykeg = (uma_keg_t)m;
3118 
3119 	/* "manually" create the initial zone */
3120 	memset(&args, 0, sizeof(args));
3121 	args.name = "UMA Kegs";
3122 	args.size = ksize;
3123 	args.ctor = keg_ctor;
3124 	args.dtor = keg_dtor;
3125 	args.uminit = zero_init;
3126 	args.fini = NULL;
3127 	args.keg = primarykeg;
3128 	args.align = UMA_SUPER_ALIGN - 1;
3129 	args.flags = UMA_ZFLAG_INTERNAL;
3130 	zone_ctor(kegs, zsize, &args, M_WAITOK);
3131 
3132 	args.name = "UMA Zones";
3133 	args.size = zsize;
3134 	args.ctor = zone_ctor;
3135 	args.dtor = zone_dtor;
3136 	args.uminit = zero_init;
3137 	args.fini = NULL;
3138 	args.keg = NULL;
3139 	args.align = UMA_SUPER_ALIGN - 1;
3140 	args.flags = UMA_ZFLAG_INTERNAL;
3141 	zone_ctor(zones, zsize, &args, M_WAITOK);
3142 
3143 	/* Now make zones for slab headers */
3144 	slabzones[0] = uma_zcreate("UMA Slabs 0", SLABZONE0_SIZE,
3145 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
3146 	slabzones[1] = uma_zcreate("UMA Slabs 1", SLABZONE1_SIZE,
3147 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
3148 
3149 	hashzone = uma_zcreate("UMA Hash",
3150 	    sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT,
3151 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
3152 
3153 	bucket_init();
3154 	smr_init();
3155 }
3156 
3157 #ifndef UMA_MD_SMALL_ALLOC
3158 extern void vm_radix_reserve_kva(void);
3159 #endif
3160 
3161 /*
3162  * Advertise the availability of normal kva allocations and switch to
3163  * the default back-end allocator.  Marks the KVA we consumed on startup
3164  * as used in the map.
3165  */
3166 void
3167 uma_startup2(void)
3168 {
3169 
3170 	if (bootstart != bootmem) {
3171 		vm_map_lock(kernel_map);
3172 		(void)vm_map_insert(kernel_map, NULL, 0, bootstart, bootmem,
3173 		    VM_PROT_RW, VM_PROT_RW, MAP_NOFAULT);
3174 		vm_map_unlock(kernel_map);
3175 	}
3176 
3177 #ifndef UMA_MD_SMALL_ALLOC
3178 	/* Set up radix zone to use noobj_alloc. */
3179 	vm_radix_reserve_kva();
3180 #endif
3181 
3182 	booted = BOOT_KVA;
3183 	zone_foreach_unlocked(zone_kva_available, NULL);
3184 	bucket_enable();
3185 }
3186 
3187 /*
3188  * Allocate counters as early as possible so that boot-time allocations are
3189  * accounted more precisely.
3190  */
3191 static void
3192 uma_startup_pcpu(void *arg __unused)
3193 {
3194 
3195 	zone_foreach_unlocked(zone_alloc_counters, NULL);
3196 	booted = BOOT_PCPU;
3197 }
3198 SYSINIT(uma_startup_pcpu, SI_SUB_COUNTER, SI_ORDER_ANY, uma_startup_pcpu, NULL);
3199 
3200 /*
3201  * Finish our initialization steps.
3202  */
3203 static void
3204 uma_startup3(void *arg __unused)
3205 {
3206 
3207 #ifdef INVARIANTS
3208 	TUNABLE_INT_FETCH("vm.debug.divisor", &dbg_divisor);
3209 	uma_dbg_cnt = counter_u64_alloc(M_WAITOK);
3210 	uma_skip_cnt = counter_u64_alloc(M_WAITOK);
3211 #endif
3212 	zone_foreach_unlocked(zone_alloc_sysctl, NULL);
3213 	booted = BOOT_RUNNING;
3214 
3215 	EVENTHANDLER_REGISTER(shutdown_post_sync, uma_shutdown, NULL,
3216 	    EVENTHANDLER_PRI_FIRST);
3217 }
3218 SYSINIT(uma_startup3, SI_SUB_VM_CONF, SI_ORDER_SECOND, uma_startup3, NULL);
3219 
3220 static void
3221 uma_startup4(void *arg __unused)
3222 {
3223 	TIMEOUT_TASK_INIT(taskqueue_thread, &uma_timeout_task, 0, uma_timeout,
3224 	    NULL);
3225 	taskqueue_enqueue_timeout(taskqueue_thread, &uma_timeout_task,
3226 	    UMA_TIMEOUT * hz);
3227 }
3228 SYSINIT(uma_startup4, SI_SUB_TASKQ, SI_ORDER_ANY, uma_startup4, NULL);
3229 
3230 static void
3231 uma_shutdown(void)
3232 {
3233 
3234 	booted = BOOT_SHUTDOWN;
3235 }
3236 
3237 static uma_keg_t
3238 uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini,
3239 		int align, uint32_t flags)
3240 {
3241 	struct uma_kctor_args args;
3242 
3243 	args.size = size;
3244 	args.uminit = uminit;
3245 	args.fini = fini;
3246 	args.align = align;
3247 	args.flags = flags;
3248 	args.zone = zone;
3249 	return (zone_alloc_item(kegs, &args, UMA_ANYDOMAIN, M_WAITOK));
3250 }
3251 
3252 
3253 static void
3254 check_align_mask(unsigned int mask)
3255 {
3256 
3257 	KASSERT(powerof2(mask + 1),
3258 	    ("UMA: %s: Not the mask of a power of 2 (%#x)", __func__, mask));
3259 	/*
3260 	 * Make sure the stored align mask doesn't have its highest bit set,
3261 	 * which would cause implementation-defined behavior when passing it as
3262 	 * the 'align' argument of uma_zcreate().  Such very large alignments do
3263 	 * not make sense anyway.
3264 	 */
3265 	KASSERT(mask <= INT_MAX,
3266 	    ("UMA: %s: Mask too big (%#x)", __func__, mask));
3267 }
3268 
3269 /* Public functions */
3270 /* See uma.h */
3271 void
3272 uma_set_cache_align_mask(unsigned int mask)
3273 {
3274 
3275 	check_align_mask(mask);
3276 	uma_cache_align_mask = mask;
3277 }
3278 
3279 /* Returns the alignment mask to use to request cache alignment. */
3280 unsigned int
3281 uma_get_cache_align_mask(void)
3282 {
3283 	return (uma_cache_align_mask);
3284 }
3285 
3286 /* See uma.h */
3287 uma_zone_t
3288 uma_zcreate(const char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
3289 		uma_init uminit, uma_fini fini, int align, uint32_t flags)
3290 
3291 {
3292 	struct uma_zctor_args args;
3293 	uma_zone_t res;
3294 
3295 	check_align_mask(align);
3296 
3297 	/* This stuff is essential for the zone ctor */
3298 	memset(&args, 0, sizeof(args));
3299 	args.name = name;
3300 	args.size = size;
3301 	args.ctor = ctor;
3302 	args.dtor = dtor;
3303 	args.uminit = uminit;
3304 	args.fini = fini;
3305 #if defined(INVARIANTS) && !defined(KASAN) && !defined(KMSAN)
3306 	/*
3307 	 * Inject procedures which check for memory use after free if we are
3308 	 * allowed to scramble the memory while it is not allocated.  This
3309 	 * requires that: UMA is actually able to access the memory, no init
3310 	 * or fini procedures, no dependency on the initial value of the
3311 	 * memory, and no (legitimate) use of the memory after free.  Note,
3312 	 * the ctor and dtor do not need to be empty.
3313 	 */
3314 	if ((!(flags & (UMA_ZONE_ZINIT | UMA_ZONE_NOTOUCH |
3315 	    UMA_ZONE_NOFREE))) && uminit == NULL && fini == NULL) {
3316 		args.uminit = trash_init;
3317 		args.fini = trash_fini;
3318 	}
3319 #endif
3320 	args.align = align;
3321 	args.flags = flags;
3322 	args.keg = NULL;
3323 
3324 	sx_xlock(&uma_reclaim_lock);
3325 	res = zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK);
3326 	sx_xunlock(&uma_reclaim_lock);
3327 
3328 	return (res);
3329 }
3330 
3331 /* See uma.h */
3332 uma_zone_t
3333 uma_zsecond_create(const char *name, uma_ctor ctor, uma_dtor dtor,
3334     uma_init zinit, uma_fini zfini, uma_zone_t primary)
3335 {
3336 	struct uma_zctor_args args;
3337 	uma_keg_t keg;
3338 	uma_zone_t res;
3339 
3340 	keg = primary->uz_keg;
3341 	memset(&args, 0, sizeof(args));
3342 	args.name = name;
3343 	args.size = keg->uk_size;
3344 	args.ctor = ctor;
3345 	args.dtor = dtor;
3346 	args.uminit = zinit;
3347 	args.fini = zfini;
3348 	args.align = keg->uk_align;
3349 	args.flags = keg->uk_flags | UMA_ZONE_SECONDARY;
3350 	args.keg = keg;
3351 
3352 	sx_xlock(&uma_reclaim_lock);
3353 	res = zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK);
3354 	sx_xunlock(&uma_reclaim_lock);
3355 
3356 	return (res);
3357 }
3358 
3359 /* See uma.h */
3360 uma_zone_t
3361 uma_zcache_create(const char *name, int size, uma_ctor ctor, uma_dtor dtor,
3362     uma_init zinit, uma_fini zfini, uma_import zimport, uma_release zrelease,
3363     void *arg, int flags)
3364 {
3365 	struct uma_zctor_args args;
3366 
3367 	memset(&args, 0, sizeof(args));
3368 	args.name = name;
3369 	args.size = size;
3370 	args.ctor = ctor;
3371 	args.dtor = dtor;
3372 	args.uminit = zinit;
3373 	args.fini = zfini;
3374 	args.import = zimport;
3375 	args.release = zrelease;
3376 	args.arg = arg;
3377 	args.align = 0;
3378 	args.flags = flags | UMA_ZFLAG_CACHE;
3379 
3380 	return (zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK));
3381 }
3382 
3383 /* See uma.h */
3384 void
3385 uma_zdestroy(uma_zone_t zone)
3386 {
3387 
3388 	/*
3389 	 * Large slabs are expensive to reclaim, so don't bother doing
3390 	 * unnecessary work if we're shutting down.
3391 	 */
3392 	if (booted == BOOT_SHUTDOWN &&
3393 	    zone->uz_fini == NULL && zone->uz_release == zone_release)
3394 		return;
3395 	sx_xlock(&uma_reclaim_lock);
3396 	zone_free_item(zones, zone, NULL, SKIP_NONE);
3397 	sx_xunlock(&uma_reclaim_lock);
3398 }
3399 
3400 void
3401 uma_zwait(uma_zone_t zone)
3402 {
3403 
3404 	if ((zone->uz_flags & UMA_ZONE_SMR) != 0)
3405 		uma_zfree_smr(zone, uma_zalloc_smr(zone, M_WAITOK));
3406 	else if ((zone->uz_flags & UMA_ZONE_PCPU) != 0)
3407 		uma_zfree_pcpu(zone, uma_zalloc_pcpu(zone, M_WAITOK));
3408 	else
3409 		uma_zfree(zone, uma_zalloc(zone, M_WAITOK));
3410 }
3411 
3412 void *
3413 uma_zalloc_pcpu_arg(uma_zone_t zone, void *udata, int flags)
3414 {
3415 	void *item, *pcpu_item;
3416 #ifdef SMP
3417 	int i;
3418 
3419 	MPASS(zone->uz_flags & UMA_ZONE_PCPU);
3420 #endif
3421 	item = uma_zalloc_arg(zone, udata, flags & ~M_ZERO);
3422 	if (item == NULL)
3423 		return (NULL);
3424 	pcpu_item = zpcpu_base_to_offset(item);
3425 	if (flags & M_ZERO) {
3426 #ifdef SMP
3427 		for (i = 0; i <= mp_maxid; i++)
3428 			bzero(zpcpu_get_cpu(pcpu_item, i), zone->uz_size);
3429 #else
3430 		bzero(item, zone->uz_size);
3431 #endif
3432 	}
3433 	return (pcpu_item);
3434 }
3435 
3436 /*
3437  * A stub while both regular and pcpu cases are identical.
3438  */
3439 void
3440 uma_zfree_pcpu_arg(uma_zone_t zone, void *pcpu_item, void *udata)
3441 {
3442 	void *item;
3443 
3444 #ifdef SMP
3445 	MPASS(zone->uz_flags & UMA_ZONE_PCPU);
3446 #endif
3447 
3448         /* uma_zfree_pcu_*(..., NULL) does nothing, to match free(9). */
3449         if (pcpu_item == NULL)
3450                 return;
3451 
3452 	item = zpcpu_offset_to_base(pcpu_item);
3453 	uma_zfree_arg(zone, item, udata);
3454 }
3455 
3456 static inline void *
3457 item_ctor(uma_zone_t zone, int uz_flags, int size, void *udata, int flags,
3458     void *item)
3459 {
3460 #ifdef INVARIANTS
3461 	bool skipdbg;
3462 #endif
3463 
3464 	kasan_mark_item_valid(zone, item);
3465 	kmsan_mark_item_uninitialized(zone, item);
3466 
3467 #ifdef INVARIANTS
3468 	skipdbg = uma_dbg_zskip(zone, item);
3469 	if (!skipdbg && (uz_flags & UMA_ZFLAG_TRASH) != 0 &&
3470 	    zone->uz_ctor != trash_ctor)
3471 		trash_ctor(item, size, zone, flags);
3472 #endif
3473 
3474 	/* Check flags before loading ctor pointer. */
3475 	if (__predict_false((uz_flags & UMA_ZFLAG_CTORDTOR) != 0) &&
3476 	    __predict_false(zone->uz_ctor != NULL) &&
3477 	    zone->uz_ctor(item, size, udata, flags) != 0) {
3478 		counter_u64_add(zone->uz_fails, 1);
3479 		zone_free_item(zone, item, udata, SKIP_DTOR | SKIP_CNT);
3480 		return (NULL);
3481 	}
3482 #ifdef INVARIANTS
3483 	if (!skipdbg)
3484 		uma_dbg_alloc(zone, NULL, item);
3485 #endif
3486 	if (__predict_false(flags & M_ZERO))
3487 		return (memset(item, 0, size));
3488 
3489 	return (item);
3490 }
3491 
3492 static inline void
3493 item_dtor(uma_zone_t zone, void *item, int size, void *udata,
3494     enum zfreeskip skip)
3495 {
3496 #ifdef INVARIANTS
3497 	bool skipdbg;
3498 
3499 	skipdbg = uma_dbg_zskip(zone, item);
3500 	if (skip == SKIP_NONE && !skipdbg) {
3501 		if ((zone->uz_flags & UMA_ZONE_MALLOC) != 0)
3502 			uma_dbg_free(zone, udata, item);
3503 		else
3504 			uma_dbg_free(zone, NULL, item);
3505 	}
3506 #endif
3507 	if (__predict_true(skip < SKIP_DTOR)) {
3508 		if (zone->uz_dtor != NULL)
3509 			zone->uz_dtor(item, size, udata);
3510 #ifdef INVARIANTS
3511 		if (!skipdbg && (zone->uz_flags & UMA_ZFLAG_TRASH) != 0 &&
3512 		    zone->uz_dtor != trash_dtor)
3513 			trash_dtor(item, size, zone);
3514 #endif
3515 	}
3516 	kasan_mark_item_invalid(zone, item);
3517 }
3518 
3519 #ifdef NUMA
3520 static int
3521 item_domain(void *item)
3522 {
3523 	int domain;
3524 
3525 	domain = vm_phys_domain(vtophys(item));
3526 	KASSERT(domain >= 0 && domain < vm_ndomains,
3527 	    ("%s: unknown domain for item %p", __func__, item));
3528 	return (domain);
3529 }
3530 #endif
3531 
3532 #if defined(INVARIANTS) || defined(DEBUG_MEMGUARD) || defined(WITNESS)
3533 #if defined(INVARIANTS) && (defined(DDB) || defined(STACK))
3534 #include <sys/stack.h>
3535 #endif
3536 #define	UMA_ZALLOC_DEBUG
3537 static int
3538 uma_zalloc_debug(uma_zone_t zone, void **itemp, void *udata, int flags)
3539 {
3540 	int error;
3541 
3542 	error = 0;
3543 #ifdef WITNESS
3544 	if (flags & M_WAITOK) {
3545 		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
3546 		    "uma_zalloc_debug: zone \"%s\"", zone->uz_name);
3547 	}
3548 #endif
3549 
3550 #ifdef INVARIANTS
3551 	KASSERT((flags & M_EXEC) == 0,
3552 	    ("uma_zalloc_debug: called with M_EXEC"));
3553 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
3554 	    ("uma_zalloc_debug: called within spinlock or critical section"));
3555 	KASSERT((zone->uz_flags & UMA_ZONE_PCPU) == 0 || (flags & M_ZERO) == 0,
3556 	    ("uma_zalloc_debug: allocating from a pcpu zone with M_ZERO"));
3557 
3558 	_Static_assert(M_NOWAIT != 0 && M_WAITOK != 0,
3559 	    "M_NOWAIT and M_WAITOK must be non-zero for this assertion:");
3560 #if 0
3561 	/*
3562 	 * Give the #elif clause time to find problems, then remove it
3563 	 * and enable this.  (Remove <sys/stack.h> above, too.)
3564 	 */
3565 	KASSERT((flags & (M_NOWAIT|M_WAITOK)) == M_NOWAIT ||
3566 	    (flags & (M_NOWAIT|M_WAITOK)) == M_WAITOK,
3567 	    ("uma_zalloc_debug: must pass one of M_NOWAIT or M_WAITOK"));
3568 #elif defined(DDB) || defined(STACK)
3569 	if (__predict_false((flags & (M_NOWAIT|M_WAITOK)) != M_NOWAIT &&
3570 	    (flags & (M_NOWAIT|M_WAITOK)) != M_WAITOK)) {
3571 		static int stack_count;
3572 		struct stack st;
3573 
3574 		if (stack_count < 10) {
3575 			++stack_count;
3576 			printf("uma_zalloc* called with bad WAIT flags:\n");
3577 			stack_save(&st);
3578 			stack_print(&st);
3579 		}
3580 	}
3581 #endif
3582 #endif
3583 
3584 #ifdef DEBUG_MEMGUARD
3585 	if ((zone->uz_flags & (UMA_ZONE_SMR | UMA_ZFLAG_CACHE)) == 0 &&
3586 	    memguard_cmp_zone(zone)) {
3587 		void *item;
3588 		item = memguard_alloc(zone->uz_size, flags);
3589 		if (item != NULL) {
3590 			error = EJUSTRETURN;
3591 			if (zone->uz_init != NULL &&
3592 			    zone->uz_init(item, zone->uz_size, flags) != 0) {
3593 				*itemp = NULL;
3594 				return (error);
3595 			}
3596 			if (zone->uz_ctor != NULL &&
3597 			    zone->uz_ctor(item, zone->uz_size, udata,
3598 			    flags) != 0) {
3599 				counter_u64_add(zone->uz_fails, 1);
3600 				if (zone->uz_fini != NULL)
3601 					zone->uz_fini(item, zone->uz_size);
3602 				*itemp = NULL;
3603 				return (error);
3604 			}
3605 			*itemp = item;
3606 			return (error);
3607 		}
3608 		/* This is unfortunate but should not be fatal. */
3609 	}
3610 #endif
3611 	return (error);
3612 }
3613 
3614 static int
3615 uma_zfree_debug(uma_zone_t zone, void *item, void *udata)
3616 {
3617 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
3618 	    ("uma_zfree_debug: called with spinlock or critical section held"));
3619 
3620 #ifdef DEBUG_MEMGUARD
3621 	if ((zone->uz_flags & (UMA_ZONE_SMR | UMA_ZFLAG_CACHE)) == 0 &&
3622 	    is_memguard_addr(item)) {
3623 		if (zone->uz_dtor != NULL)
3624 			zone->uz_dtor(item, zone->uz_size, udata);
3625 		if (zone->uz_fini != NULL)
3626 			zone->uz_fini(item, zone->uz_size);
3627 		memguard_free(item);
3628 		return (EJUSTRETURN);
3629 	}
3630 #endif
3631 	return (0);
3632 }
3633 #endif
3634 
3635 static inline void *
3636 cache_alloc_item(uma_zone_t zone, uma_cache_t cache, uma_cache_bucket_t bucket,
3637     void *udata, int flags)
3638 {
3639 	void *item;
3640 	int size, uz_flags;
3641 
3642 	item = cache_bucket_pop(cache, bucket);
3643 	size = cache_uz_size(cache);
3644 	uz_flags = cache_uz_flags(cache);
3645 	critical_exit();
3646 	return (item_ctor(zone, uz_flags, size, udata, flags, item));
3647 }
3648 
3649 static __noinline void *
3650 cache_alloc_retry(uma_zone_t zone, uma_cache_t cache, void *udata, int flags)
3651 {
3652 	uma_cache_bucket_t bucket;
3653 	int domain;
3654 
3655 	while (cache_alloc(zone, cache, udata, flags)) {
3656 		cache = &zone->uz_cpu[curcpu];
3657 		bucket = &cache->uc_allocbucket;
3658 		if (__predict_false(bucket->ucb_cnt == 0))
3659 			continue;
3660 		return (cache_alloc_item(zone, cache, bucket, udata, flags));
3661 	}
3662 	critical_exit();
3663 
3664 	/*
3665 	 * We can not get a bucket so try to return a single item.
3666 	 */
3667 	if (zone->uz_flags & UMA_ZONE_FIRSTTOUCH)
3668 		domain = PCPU_GET(domain);
3669 	else
3670 		domain = UMA_ANYDOMAIN;
3671 	return (zone_alloc_item(zone, udata, domain, flags));
3672 }
3673 
3674 /* See uma.h */
3675 void *
3676 uma_zalloc_smr(uma_zone_t zone, int flags)
3677 {
3678 	uma_cache_bucket_t bucket;
3679 	uma_cache_t cache;
3680 
3681 	CTR3(KTR_UMA, "uma_zalloc_smr zone %s(%p) flags %d", zone->uz_name,
3682 	    zone, flags);
3683 
3684 #ifdef UMA_ZALLOC_DEBUG
3685 	void *item;
3686 
3687 	KASSERT((zone->uz_flags & UMA_ZONE_SMR) != 0,
3688 	    ("uma_zalloc_arg: called with non-SMR zone."));
3689 	if (uma_zalloc_debug(zone, &item, NULL, flags) == EJUSTRETURN)
3690 		return (item);
3691 #endif
3692 
3693 	critical_enter();
3694 	cache = &zone->uz_cpu[curcpu];
3695 	bucket = &cache->uc_allocbucket;
3696 	if (__predict_false(bucket->ucb_cnt == 0))
3697 		return (cache_alloc_retry(zone, cache, NULL, flags));
3698 	return (cache_alloc_item(zone, cache, bucket, NULL, flags));
3699 }
3700 
3701 /* See uma.h */
3702 void *
3703 uma_zalloc_arg(uma_zone_t zone, void *udata, int flags)
3704 {
3705 	uma_cache_bucket_t bucket;
3706 	uma_cache_t cache;
3707 
3708 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
3709 	random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
3710 
3711 	/* This is the fast path allocation */
3712 	CTR3(KTR_UMA, "uma_zalloc_arg zone %s(%p) flags %d", zone->uz_name,
3713 	    zone, flags);
3714 
3715 #ifdef UMA_ZALLOC_DEBUG
3716 	void *item;
3717 
3718 	KASSERT((zone->uz_flags & UMA_ZONE_SMR) == 0,
3719 	    ("uma_zalloc_arg: called with SMR zone."));
3720 	if (uma_zalloc_debug(zone, &item, udata, flags) == EJUSTRETURN)
3721 		return (item);
3722 #endif
3723 
3724 	/*
3725 	 * If possible, allocate from the per-CPU cache.  There are two
3726 	 * requirements for safe access to the per-CPU cache: (1) the thread
3727 	 * accessing the cache must not be preempted or yield during access,
3728 	 * and (2) the thread must not migrate CPUs without switching which
3729 	 * cache it accesses.  We rely on a critical section to prevent
3730 	 * preemption and migration.  We release the critical section in
3731 	 * order to acquire the zone mutex if we are unable to allocate from
3732 	 * the current cache; when we re-acquire the critical section, we
3733 	 * must detect and handle migration if it has occurred.
3734 	 */
3735 	critical_enter();
3736 	cache = &zone->uz_cpu[curcpu];
3737 	bucket = &cache->uc_allocbucket;
3738 	if (__predict_false(bucket->ucb_cnt == 0))
3739 		return (cache_alloc_retry(zone, cache, udata, flags));
3740 	return (cache_alloc_item(zone, cache, bucket, udata, flags));
3741 }
3742 
3743 /*
3744  * Replenish an alloc bucket and possibly restore an old one.  Called in
3745  * a critical section.  Returns in a critical section.
3746  *
3747  * A false return value indicates an allocation failure.
3748  * A true return value indicates success and the caller should retry.
3749  */
3750 static __noinline bool
3751 cache_alloc(uma_zone_t zone, uma_cache_t cache, void *udata, int flags)
3752 {
3753 	uma_bucket_t bucket;
3754 	int curdomain, domain;
3755 	bool new;
3756 
3757 	CRITICAL_ASSERT(curthread);
3758 
3759 	/*
3760 	 * If we have run out of items in our alloc bucket see
3761 	 * if we can switch with the free bucket.
3762 	 *
3763 	 * SMR Zones can't re-use the free bucket until the sequence has
3764 	 * expired.
3765 	 */
3766 	if ((cache_uz_flags(cache) & UMA_ZONE_SMR) == 0 &&
3767 	    cache->uc_freebucket.ucb_cnt != 0) {
3768 		cache_bucket_swap(&cache->uc_freebucket,
3769 		    &cache->uc_allocbucket);
3770 		return (true);
3771 	}
3772 
3773 	/*
3774 	 * Discard any empty allocation bucket while we hold no locks.
3775 	 */
3776 	bucket = cache_bucket_unload_alloc(cache);
3777 	critical_exit();
3778 
3779 	if (bucket != NULL) {
3780 		KASSERT(bucket->ub_cnt == 0,
3781 		    ("cache_alloc: Entered with non-empty alloc bucket."));
3782 		bucket_free(zone, bucket, udata);
3783 	}
3784 
3785 	/*
3786 	 * Attempt to retrieve the item from the per-CPU cache has failed, so
3787 	 * we must go back to the zone.  This requires the zdom lock, so we
3788 	 * must drop the critical section, then re-acquire it when we go back
3789 	 * to the cache.  Since the critical section is released, we may be
3790 	 * preempted or migrate.  As such, make sure not to maintain any
3791 	 * thread-local state specific to the cache from prior to releasing
3792 	 * the critical section.
3793 	 */
3794 	domain = PCPU_GET(domain);
3795 	if ((cache_uz_flags(cache) & UMA_ZONE_ROUNDROBIN) != 0 ||
3796 	    VM_DOMAIN_EMPTY(domain))
3797 		domain = zone_domain_highest(zone, domain);
3798 	bucket = cache_fetch_bucket(zone, cache, domain);
3799 	if (bucket == NULL && zone->uz_bucket_size != 0 && !bucketdisable) {
3800 		bucket = zone_alloc_bucket(zone, udata, domain, flags);
3801 		new = true;
3802 	} else {
3803 		new = false;
3804 	}
3805 
3806 	CTR3(KTR_UMA, "uma_zalloc: zone %s(%p) bucket zone returned %p",
3807 	    zone->uz_name, zone, bucket);
3808 	if (bucket == NULL) {
3809 		critical_enter();
3810 		return (false);
3811 	}
3812 
3813 	/*
3814 	 * See if we lost the race or were migrated.  Cache the
3815 	 * initialized bucket to make this less likely or claim
3816 	 * the memory directly.
3817 	 */
3818 	critical_enter();
3819 	cache = &zone->uz_cpu[curcpu];
3820 	if (cache->uc_allocbucket.ucb_bucket == NULL &&
3821 	    ((cache_uz_flags(cache) & UMA_ZONE_FIRSTTOUCH) == 0 ||
3822 	    (curdomain = PCPU_GET(domain)) == domain ||
3823 	    VM_DOMAIN_EMPTY(curdomain))) {
3824 		if (new)
3825 			atomic_add_long(&ZDOM_GET(zone, domain)->uzd_imax,
3826 			    bucket->ub_cnt);
3827 		cache_bucket_load_alloc(cache, bucket);
3828 		return (true);
3829 	}
3830 
3831 	/*
3832 	 * We lost the race, release this bucket and start over.
3833 	 */
3834 	critical_exit();
3835 	zone_put_bucket(zone, domain, bucket, udata, !new);
3836 	critical_enter();
3837 
3838 	return (true);
3839 }
3840 
3841 void *
3842 uma_zalloc_domain(uma_zone_t zone, void *udata, int domain, int flags)
3843 {
3844 #ifdef NUMA
3845 	uma_bucket_t bucket;
3846 	uma_zone_domain_t zdom;
3847 	void *item;
3848 #endif
3849 
3850 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
3851 	random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
3852 
3853 	/* This is the fast path allocation */
3854 	CTR4(KTR_UMA, "uma_zalloc_domain zone %s(%p) domain %d flags %d",
3855 	    zone->uz_name, zone, domain, flags);
3856 
3857 	KASSERT((zone->uz_flags & UMA_ZONE_SMR) == 0,
3858 	    ("uma_zalloc_domain: called with SMR zone."));
3859 #ifdef NUMA
3860 	KASSERT((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) != 0,
3861 	    ("uma_zalloc_domain: called with non-FIRSTTOUCH zone."));
3862 
3863 	if (vm_ndomains == 1)
3864 		return (uma_zalloc_arg(zone, udata, flags));
3865 
3866 #ifdef UMA_ZALLOC_DEBUG
3867 	if (uma_zalloc_debug(zone, &item, udata, flags) == EJUSTRETURN)
3868 		return (item);
3869 #endif
3870 
3871 	/*
3872 	 * Try to allocate from the bucket cache before falling back to the keg.
3873 	 * We could try harder and attempt to allocate from per-CPU caches or
3874 	 * the per-domain cross-domain buckets, but the complexity is probably
3875 	 * not worth it.  It is more important that frees of previous
3876 	 * cross-domain allocations do not blow up the cache.
3877 	 */
3878 	zdom = zone_domain_lock(zone, domain);
3879 	if ((bucket = zone_fetch_bucket(zone, zdom, false)) != NULL) {
3880 		item = bucket->ub_bucket[bucket->ub_cnt - 1];
3881 #ifdef INVARIANTS
3882 		bucket->ub_bucket[bucket->ub_cnt - 1] = NULL;
3883 #endif
3884 		bucket->ub_cnt--;
3885 		zone_put_bucket(zone, domain, bucket, udata, true);
3886 		item = item_ctor(zone, zone->uz_flags, zone->uz_size, udata,
3887 		    flags, item);
3888 		if (item != NULL) {
3889 			KASSERT(item_domain(item) == domain,
3890 			    ("%s: bucket cache item %p from wrong domain",
3891 			    __func__, item));
3892 			counter_u64_add(zone->uz_allocs, 1);
3893 		}
3894 		return (item);
3895 	}
3896 	ZDOM_UNLOCK(zdom);
3897 	return (zone_alloc_item(zone, udata, domain, flags));
3898 #else
3899 	return (uma_zalloc_arg(zone, udata, flags));
3900 #endif
3901 }
3902 
3903 /*
3904  * Find a slab with some space.  Prefer slabs that are partially used over those
3905  * that are totally full.  This helps to reduce fragmentation.
3906  *
3907  * If 'rr' is 1, search all domains starting from 'domain'.  Otherwise check
3908  * only 'domain'.
3909  */
3910 static uma_slab_t
3911 keg_first_slab(uma_keg_t keg, int domain, bool rr)
3912 {
3913 	uma_domain_t dom;
3914 	uma_slab_t slab;
3915 	int start;
3916 
3917 	KASSERT(domain >= 0 && domain < vm_ndomains,
3918 	    ("keg_first_slab: domain %d out of range", domain));
3919 	KEG_LOCK_ASSERT(keg, domain);
3920 
3921 	slab = NULL;
3922 	start = domain;
3923 	do {
3924 		dom = &keg->uk_domain[domain];
3925 		if ((slab = LIST_FIRST(&dom->ud_part_slab)) != NULL)
3926 			return (slab);
3927 		if ((slab = LIST_FIRST(&dom->ud_free_slab)) != NULL) {
3928 			LIST_REMOVE(slab, us_link);
3929 			dom->ud_free_slabs--;
3930 			LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
3931 			return (slab);
3932 		}
3933 		if (rr)
3934 			domain = (domain + 1) % vm_ndomains;
3935 	} while (domain != start);
3936 
3937 	return (NULL);
3938 }
3939 
3940 /*
3941  * Fetch an existing slab from a free or partial list.  Returns with the
3942  * keg domain lock held if a slab was found or unlocked if not.
3943  */
3944 static uma_slab_t
3945 keg_fetch_free_slab(uma_keg_t keg, int domain, bool rr, int flags)
3946 {
3947 	uma_slab_t slab;
3948 	uint32_t reserve;
3949 
3950 	/* HASH has a single free list. */
3951 	if ((keg->uk_flags & UMA_ZFLAG_HASH) != 0)
3952 		domain = 0;
3953 
3954 	KEG_LOCK(keg, domain);
3955 	reserve = (flags & M_USE_RESERVE) != 0 ? 0 : keg->uk_reserve;
3956 	if (keg->uk_domain[domain].ud_free_items <= reserve ||
3957 	    (slab = keg_first_slab(keg, domain, rr)) == NULL) {
3958 		KEG_UNLOCK(keg, domain);
3959 		return (NULL);
3960 	}
3961 	return (slab);
3962 }
3963 
3964 static uma_slab_t
3965 keg_fetch_slab(uma_keg_t keg, uma_zone_t zone, int rdomain, const int flags)
3966 {
3967 	struct vm_domainset_iter di;
3968 	uma_slab_t slab;
3969 	int aflags, domain;
3970 	bool rr;
3971 
3972 	KASSERT((flags & (M_WAITOK | M_NOVM)) != (M_WAITOK | M_NOVM),
3973 	    ("%s: invalid flags %#x", __func__, flags));
3974 
3975 restart:
3976 	/*
3977 	 * Use the keg's policy if upper layers haven't already specified a
3978 	 * domain (as happens with first-touch zones).
3979 	 *
3980 	 * To avoid races we run the iterator with the keg lock held, but that
3981 	 * means that we cannot allow the vm_domainset layer to sleep.  Thus,
3982 	 * clear M_WAITOK and handle low memory conditions locally.
3983 	 */
3984 	rr = rdomain == UMA_ANYDOMAIN;
3985 	if (rr) {
3986 		aflags = (flags & ~M_WAITOK) | M_NOWAIT;
3987 		vm_domainset_iter_policy_ref_init(&di, &keg->uk_dr, &domain,
3988 		    &aflags);
3989 	} else {
3990 		aflags = flags;
3991 		domain = rdomain;
3992 	}
3993 
3994 	for (;;) {
3995 		slab = keg_fetch_free_slab(keg, domain, rr, flags);
3996 		if (slab != NULL)
3997 			return (slab);
3998 
3999 		/*
4000 		 * M_NOVM is used to break the recursion that can otherwise
4001 		 * occur if low-level memory management routines use UMA.
4002 		 */
4003 		if ((flags & M_NOVM) == 0) {
4004 			slab = keg_alloc_slab(keg, zone, domain, flags, aflags);
4005 			if (slab != NULL)
4006 				return (slab);
4007 		}
4008 
4009 		if (!rr) {
4010 			if ((flags & M_USE_RESERVE) != 0) {
4011 				/*
4012 				 * Drain reserves from other domains before
4013 				 * giving up or sleeping.  It may be useful to
4014 				 * support per-domain reserves eventually.
4015 				 */
4016 				rdomain = UMA_ANYDOMAIN;
4017 				goto restart;
4018 			}
4019 			if ((flags & M_WAITOK) == 0)
4020 				break;
4021 			vm_wait_domain(domain);
4022 		} else if (vm_domainset_iter_policy(&di, &domain) != 0) {
4023 			if ((flags & M_WAITOK) != 0) {
4024 				vm_wait_doms(&keg->uk_dr.dr_policy->ds_mask, 0);
4025 				goto restart;
4026 			}
4027 			break;
4028 		}
4029 	}
4030 
4031 	/*
4032 	 * We might not have been able to get a slab but another cpu
4033 	 * could have while we were unlocked.  Check again before we
4034 	 * fail.
4035 	 */
4036 	if ((slab = keg_fetch_free_slab(keg, domain, rr, flags)) != NULL)
4037 		return (slab);
4038 
4039 	return (NULL);
4040 }
4041 
4042 static void *
4043 slab_alloc_item(uma_keg_t keg, uma_slab_t slab)
4044 {
4045 	uma_domain_t dom;
4046 	void *item;
4047 	int freei;
4048 
4049 	KEG_LOCK_ASSERT(keg, slab->us_domain);
4050 
4051 	dom = &keg->uk_domain[slab->us_domain];
4052 	freei = BIT_FFS(keg->uk_ipers, &slab->us_free) - 1;
4053 	BIT_CLR(keg->uk_ipers, freei, &slab->us_free);
4054 	item = slab_item(slab, keg, freei);
4055 	slab->us_freecount--;
4056 	dom->ud_free_items--;
4057 
4058 	/*
4059 	 * Move this slab to the full list.  It must be on the partial list, so
4060 	 * we do not need to update the free slab count.  In particular,
4061 	 * keg_fetch_slab() always returns slabs on the partial list.
4062 	 */
4063 	if (slab->us_freecount == 0) {
4064 		LIST_REMOVE(slab, us_link);
4065 		LIST_INSERT_HEAD(&dom->ud_full_slab, slab, us_link);
4066 	}
4067 
4068 	return (item);
4069 }
4070 
4071 static int
4072 zone_import(void *arg, void **bucket, int max, int domain, int flags)
4073 {
4074 	uma_domain_t dom;
4075 	uma_zone_t zone;
4076 	uma_slab_t slab;
4077 	uma_keg_t keg;
4078 #ifdef NUMA
4079 	int stripe;
4080 #endif
4081 	int i;
4082 
4083 	zone = arg;
4084 	slab = NULL;
4085 	keg = zone->uz_keg;
4086 	/* Try to keep the buckets totally full */
4087 	for (i = 0; i < max; ) {
4088 		if ((slab = keg_fetch_slab(keg, zone, domain, flags)) == NULL)
4089 			break;
4090 #ifdef NUMA
4091 		stripe = howmany(max, vm_ndomains);
4092 #endif
4093 		dom = &keg->uk_domain[slab->us_domain];
4094 		do {
4095 			bucket[i++] = slab_alloc_item(keg, slab);
4096 			if (keg->uk_reserve > 0 &&
4097 			    dom->ud_free_items <= keg->uk_reserve) {
4098 				/*
4099 				 * Avoid depleting the reserve after a
4100 				 * successful item allocation, even if
4101 				 * M_USE_RESERVE is specified.
4102 				 */
4103 				KEG_UNLOCK(keg, slab->us_domain);
4104 				goto out;
4105 			}
4106 #ifdef NUMA
4107 			/*
4108 			 * If the zone is striped we pick a new slab for every
4109 			 * N allocations.  Eliminating this conditional will
4110 			 * instead pick a new domain for each bucket rather
4111 			 * than stripe within each bucket.  The current option
4112 			 * produces more fragmentation and requires more cpu
4113 			 * time but yields better distribution.
4114 			 */
4115 			if ((zone->uz_flags & UMA_ZONE_ROUNDROBIN) != 0 &&
4116 			    vm_ndomains > 1 && --stripe == 0)
4117 				break;
4118 #endif
4119 		} while (slab->us_freecount != 0 && i < max);
4120 		KEG_UNLOCK(keg, slab->us_domain);
4121 
4122 		/* Don't block if we allocated any successfully. */
4123 		flags &= ~M_WAITOK;
4124 		flags |= M_NOWAIT;
4125 	}
4126 out:
4127 	return i;
4128 }
4129 
4130 static int
4131 zone_alloc_limit_hard(uma_zone_t zone, int count, int flags)
4132 {
4133 	uint64_t old, new, total, max;
4134 
4135 	/*
4136 	 * The hard case.  We're going to sleep because there were existing
4137 	 * sleepers or because we ran out of items.  This routine enforces
4138 	 * fairness by keeping fifo order.
4139 	 *
4140 	 * First release our ill gotten gains and make some noise.
4141 	 */
4142 	for (;;) {
4143 		zone_free_limit(zone, count);
4144 		zone_log_warning(zone);
4145 		zone_maxaction(zone);
4146 		if (flags & M_NOWAIT)
4147 			return (0);
4148 
4149 		/*
4150 		 * We need to allocate an item or set ourself as a sleeper
4151 		 * while the sleepq lock is held to avoid wakeup races.  This
4152 		 * is essentially a home rolled semaphore.
4153 		 */
4154 		sleepq_lock(&zone->uz_max_items);
4155 		old = zone->uz_items;
4156 		do {
4157 			MPASS(UZ_ITEMS_SLEEPERS(old) < UZ_ITEMS_SLEEPERS_MAX);
4158 			/* Cache the max since we will evaluate twice. */
4159 			max = zone->uz_max_items;
4160 			if (UZ_ITEMS_SLEEPERS(old) != 0 ||
4161 			    UZ_ITEMS_COUNT(old) >= max)
4162 				new = old + UZ_ITEMS_SLEEPER;
4163 			else
4164 				new = old + MIN(count, max - old);
4165 		} while (atomic_fcmpset_64(&zone->uz_items, &old, new) == 0);
4166 
4167 		/* We may have successfully allocated under the sleepq lock. */
4168 		if (UZ_ITEMS_SLEEPERS(new) == 0) {
4169 			sleepq_release(&zone->uz_max_items);
4170 			return (new - old);
4171 		}
4172 
4173 		/*
4174 		 * This is in a different cacheline from uz_items so that we
4175 		 * don't constantly invalidate the fastpath cacheline when we
4176 		 * adjust item counts.  This could be limited to toggling on
4177 		 * transitions.
4178 		 */
4179 		atomic_add_32(&zone->uz_sleepers, 1);
4180 		atomic_add_64(&zone->uz_sleeps, 1);
4181 
4182 		/*
4183 		 * We have added ourselves as a sleeper.  The sleepq lock
4184 		 * protects us from wakeup races.  Sleep now and then retry.
4185 		 */
4186 		sleepq_add(&zone->uz_max_items, NULL, "zonelimit", 0, 0);
4187 		sleepq_wait(&zone->uz_max_items, PVM);
4188 
4189 		/*
4190 		 * After wakeup, remove ourselves as a sleeper and try
4191 		 * again.  We no longer have the sleepq lock for protection.
4192 		 *
4193 		 * Subract ourselves as a sleeper while attempting to add
4194 		 * our count.
4195 		 */
4196 		atomic_subtract_32(&zone->uz_sleepers, 1);
4197 		old = atomic_fetchadd_64(&zone->uz_items,
4198 		    -(UZ_ITEMS_SLEEPER - count));
4199 		/* We're no longer a sleeper. */
4200 		old -= UZ_ITEMS_SLEEPER;
4201 
4202 		/*
4203 		 * If we're still at the limit, restart.  Notably do not
4204 		 * block on other sleepers.  Cache the max value to protect
4205 		 * against changes via sysctl.
4206 		 */
4207 		total = UZ_ITEMS_COUNT(old);
4208 		max = zone->uz_max_items;
4209 		if (total >= max)
4210 			continue;
4211 		/* Truncate if necessary, otherwise wake other sleepers. */
4212 		if (total + count > max) {
4213 			zone_free_limit(zone, total + count - max);
4214 			count = max - total;
4215 		} else if (total + count < max && UZ_ITEMS_SLEEPERS(old) != 0)
4216 			wakeup_one(&zone->uz_max_items);
4217 
4218 		return (count);
4219 	}
4220 }
4221 
4222 /*
4223  * Allocate 'count' items from our max_items limit.  Returns the number
4224  * available.  If M_NOWAIT is not specified it will sleep until at least
4225  * one item can be allocated.
4226  */
4227 static int
4228 zone_alloc_limit(uma_zone_t zone, int count, int flags)
4229 {
4230 	uint64_t old;
4231 	uint64_t max;
4232 
4233 	max = zone->uz_max_items;
4234 	MPASS(max > 0);
4235 
4236 	/*
4237 	 * We expect normal allocations to succeed with a simple
4238 	 * fetchadd.
4239 	 */
4240 	old = atomic_fetchadd_64(&zone->uz_items, count);
4241 	if (__predict_true(old + count <= max))
4242 		return (count);
4243 
4244 	/*
4245 	 * If we had some items and no sleepers just return the
4246 	 * truncated value.  We have to release the excess space
4247 	 * though because that may wake sleepers who weren't woken
4248 	 * because we were temporarily over the limit.
4249 	 */
4250 	if (old < max) {
4251 		zone_free_limit(zone, (old + count) - max);
4252 		return (max - old);
4253 	}
4254 	return (zone_alloc_limit_hard(zone, count, flags));
4255 }
4256 
4257 /*
4258  * Free a number of items back to the limit.
4259  */
4260 static void
4261 zone_free_limit(uma_zone_t zone, int count)
4262 {
4263 	uint64_t old;
4264 
4265 	MPASS(count > 0);
4266 
4267 	/*
4268 	 * In the common case we either have no sleepers or
4269 	 * are still over the limit and can just return.
4270 	 */
4271 	old = atomic_fetchadd_64(&zone->uz_items, -count);
4272 	if (__predict_true(UZ_ITEMS_SLEEPERS(old) == 0 ||
4273 	   UZ_ITEMS_COUNT(old) - count >= zone->uz_max_items))
4274 		return;
4275 
4276 	/*
4277 	 * Moderate the rate of wakeups.  Sleepers will continue
4278 	 * to generate wakeups if necessary.
4279 	 */
4280 	wakeup_one(&zone->uz_max_items);
4281 }
4282 
4283 static uma_bucket_t
4284 zone_alloc_bucket(uma_zone_t zone, void *udata, int domain, int flags)
4285 {
4286 	uma_bucket_t bucket;
4287 	int error, maxbucket, cnt;
4288 
4289 	CTR3(KTR_UMA, "zone_alloc_bucket zone %s(%p) domain %d", zone->uz_name,
4290 	    zone, domain);
4291 
4292 	/* Avoid allocs targeting empty domains. */
4293 	if (domain != UMA_ANYDOMAIN && VM_DOMAIN_EMPTY(domain))
4294 		domain = UMA_ANYDOMAIN;
4295 	else if ((zone->uz_flags & UMA_ZONE_ROUNDROBIN) != 0)
4296 		domain = UMA_ANYDOMAIN;
4297 
4298 	if (zone->uz_max_items > 0)
4299 		maxbucket = zone_alloc_limit(zone, zone->uz_bucket_size,
4300 		    M_NOWAIT);
4301 	else
4302 		maxbucket = zone->uz_bucket_size;
4303 	if (maxbucket == 0)
4304 		return (NULL);
4305 
4306 	/* Don't wait for buckets, preserve caller's NOVM setting. */
4307 	bucket = bucket_alloc(zone, udata, M_NOWAIT | (flags & M_NOVM));
4308 	if (bucket == NULL) {
4309 		cnt = 0;
4310 		goto out;
4311 	}
4312 
4313 	bucket->ub_cnt = zone->uz_import(zone->uz_arg, bucket->ub_bucket,
4314 	    MIN(maxbucket, bucket->ub_entries), domain, flags);
4315 
4316 	/*
4317 	 * Initialize the memory if necessary.
4318 	 */
4319 	if (bucket->ub_cnt != 0 && zone->uz_init != NULL) {
4320 		int i;
4321 
4322 		for (i = 0; i < bucket->ub_cnt; i++) {
4323 			kasan_mark_item_valid(zone, bucket->ub_bucket[i]);
4324 			error = zone->uz_init(bucket->ub_bucket[i],
4325 			    zone->uz_size, flags);
4326 			kasan_mark_item_invalid(zone, bucket->ub_bucket[i]);
4327 			if (error != 0)
4328 				break;
4329 		}
4330 
4331 		/*
4332 		 * If we couldn't initialize the whole bucket, put the
4333 		 * rest back onto the freelist.
4334 		 */
4335 		if (i != bucket->ub_cnt) {
4336 			zone->uz_release(zone->uz_arg, &bucket->ub_bucket[i],
4337 			    bucket->ub_cnt - i);
4338 #ifdef INVARIANTS
4339 			bzero(&bucket->ub_bucket[i],
4340 			    sizeof(void *) * (bucket->ub_cnt - i));
4341 #endif
4342 			bucket->ub_cnt = i;
4343 		}
4344 	}
4345 
4346 	cnt = bucket->ub_cnt;
4347 	if (bucket->ub_cnt == 0) {
4348 		bucket_free(zone, bucket, udata);
4349 		counter_u64_add(zone->uz_fails, 1);
4350 		bucket = NULL;
4351 	}
4352 out:
4353 	if (zone->uz_max_items > 0 && cnt < maxbucket)
4354 		zone_free_limit(zone, maxbucket - cnt);
4355 
4356 	return (bucket);
4357 }
4358 
4359 /*
4360  * Allocates a single item from a zone.
4361  *
4362  * Arguments
4363  *	zone   The zone to alloc for.
4364  *	udata  The data to be passed to the constructor.
4365  *	domain The domain to allocate from or UMA_ANYDOMAIN.
4366  *	flags  M_WAITOK, M_NOWAIT, M_ZERO.
4367  *
4368  * Returns
4369  *	NULL if there is no memory and M_NOWAIT is set
4370  *	An item if successful
4371  */
4372 
4373 static void *
4374 zone_alloc_item(uma_zone_t zone, void *udata, int domain, int flags)
4375 {
4376 	void *item;
4377 
4378 	if (zone->uz_max_items > 0 && zone_alloc_limit(zone, 1, flags) == 0) {
4379 		counter_u64_add(zone->uz_fails, 1);
4380 		return (NULL);
4381 	}
4382 
4383 	/* Avoid allocs targeting empty domains. */
4384 	if (domain != UMA_ANYDOMAIN && VM_DOMAIN_EMPTY(domain))
4385 		domain = UMA_ANYDOMAIN;
4386 
4387 	if (zone->uz_import(zone->uz_arg, &item, 1, domain, flags) != 1)
4388 		goto fail_cnt;
4389 
4390 	/*
4391 	 * We have to call both the zone's init (not the keg's init)
4392 	 * and the zone's ctor.  This is because the item is going from
4393 	 * a keg slab directly to the user, and the user is expecting it
4394 	 * to be both zone-init'd as well as zone-ctor'd.
4395 	 */
4396 	if (zone->uz_init != NULL) {
4397 		int error;
4398 
4399 		kasan_mark_item_valid(zone, item);
4400 		error = zone->uz_init(item, zone->uz_size, flags);
4401 		kasan_mark_item_invalid(zone, item);
4402 		if (error != 0) {
4403 			zone_free_item(zone, item, udata, SKIP_FINI | SKIP_CNT);
4404 			goto fail_cnt;
4405 		}
4406 	}
4407 	item = item_ctor(zone, zone->uz_flags, zone->uz_size, udata, flags,
4408 	    item);
4409 	if (item == NULL)
4410 		goto fail;
4411 
4412 	counter_u64_add(zone->uz_allocs, 1);
4413 	CTR3(KTR_UMA, "zone_alloc_item item %p from %s(%p)", item,
4414 	    zone->uz_name, zone);
4415 
4416 	return (item);
4417 
4418 fail_cnt:
4419 	counter_u64_add(zone->uz_fails, 1);
4420 fail:
4421 	if (zone->uz_max_items > 0)
4422 		zone_free_limit(zone, 1);
4423 	CTR2(KTR_UMA, "zone_alloc_item failed from %s(%p)",
4424 	    zone->uz_name, zone);
4425 
4426 	return (NULL);
4427 }
4428 
4429 /* See uma.h */
4430 void
4431 uma_zfree_smr(uma_zone_t zone, void *item)
4432 {
4433 	uma_cache_t cache;
4434 	uma_cache_bucket_t bucket;
4435 	int itemdomain;
4436 #ifdef NUMA
4437 	int uz_flags;
4438 #endif
4439 
4440 	CTR3(KTR_UMA, "uma_zfree_smr zone %s(%p) item %p",
4441 	    zone->uz_name, zone, item);
4442 
4443 #ifdef UMA_ZALLOC_DEBUG
4444 	KASSERT((zone->uz_flags & UMA_ZONE_SMR) != 0,
4445 	    ("uma_zfree_smr: called with non-SMR zone."));
4446 	KASSERT(item != NULL, ("uma_zfree_smr: Called with NULL pointer."));
4447 	SMR_ASSERT_NOT_ENTERED(zone->uz_smr);
4448 	if (uma_zfree_debug(zone, item, NULL) == EJUSTRETURN)
4449 		return;
4450 #endif
4451 	cache = &zone->uz_cpu[curcpu];
4452 	itemdomain = 0;
4453 #ifdef NUMA
4454 	uz_flags = cache_uz_flags(cache);
4455 	if ((uz_flags & UMA_ZONE_FIRSTTOUCH) != 0)
4456 		itemdomain = item_domain(item);
4457 #endif
4458 	critical_enter();
4459 	do {
4460 		cache = &zone->uz_cpu[curcpu];
4461 		/* SMR Zones must free to the free bucket. */
4462 		bucket = &cache->uc_freebucket;
4463 #ifdef NUMA
4464 		if ((uz_flags & UMA_ZONE_FIRSTTOUCH) != 0 &&
4465 		    PCPU_GET(domain) != itemdomain) {
4466 			bucket = &cache->uc_crossbucket;
4467 		}
4468 #endif
4469 		if (__predict_true(bucket->ucb_cnt < bucket->ucb_entries)) {
4470 			cache_bucket_push(cache, bucket, item);
4471 			critical_exit();
4472 			return;
4473 		}
4474 	} while (cache_free(zone, cache, NULL, itemdomain));
4475 	critical_exit();
4476 
4477 	/*
4478 	 * If nothing else caught this, we'll just do an internal free.
4479 	 */
4480 	zone_free_item(zone, item, NULL, SKIP_NONE);
4481 }
4482 
4483 /* See uma.h */
4484 void
4485 uma_zfree_arg(uma_zone_t zone, void *item, void *udata)
4486 {
4487 	uma_cache_t cache;
4488 	uma_cache_bucket_t bucket;
4489 	int itemdomain, uz_flags;
4490 
4491 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
4492 	random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
4493 
4494 	CTR3(KTR_UMA, "uma_zfree_arg zone %s(%p) item %p",
4495 	    zone->uz_name, zone, item);
4496 
4497 #ifdef UMA_ZALLOC_DEBUG
4498 	KASSERT((zone->uz_flags & UMA_ZONE_SMR) == 0,
4499 	    ("uma_zfree_arg: called with SMR zone."));
4500 	if (uma_zfree_debug(zone, item, udata) == EJUSTRETURN)
4501 		return;
4502 #endif
4503         /* uma_zfree(..., NULL) does nothing, to match free(9). */
4504         if (item == NULL)
4505                 return;
4506 
4507 	/*
4508 	 * We are accessing the per-cpu cache without a critical section to
4509 	 * fetch size and flags.  This is acceptable, if we are preempted we
4510 	 * will simply read another cpu's line.
4511 	 */
4512 	cache = &zone->uz_cpu[curcpu];
4513 	uz_flags = cache_uz_flags(cache);
4514 	if (UMA_ALWAYS_CTORDTOR ||
4515 	    __predict_false((uz_flags & UMA_ZFLAG_CTORDTOR) != 0))
4516 		item_dtor(zone, item, cache_uz_size(cache), udata, SKIP_NONE);
4517 
4518 	/*
4519 	 * The race here is acceptable.  If we miss it we'll just have to wait
4520 	 * a little longer for the limits to be reset.
4521 	 */
4522 	if (__predict_false(uz_flags & UMA_ZFLAG_LIMIT)) {
4523 		if (atomic_load_32(&zone->uz_sleepers) > 0)
4524 			goto zfree_item;
4525 	}
4526 
4527 	/*
4528 	 * If possible, free to the per-CPU cache.  There are two
4529 	 * requirements for safe access to the per-CPU cache: (1) the thread
4530 	 * accessing the cache must not be preempted or yield during access,
4531 	 * and (2) the thread must not migrate CPUs without switching which
4532 	 * cache it accesses.  We rely on a critical section to prevent
4533 	 * preemption and migration.  We release the critical section in
4534 	 * order to acquire the zone mutex if we are unable to free to the
4535 	 * current cache; when we re-acquire the critical section, we must
4536 	 * detect and handle migration if it has occurred.
4537 	 */
4538 	itemdomain = 0;
4539 #ifdef NUMA
4540 	if ((uz_flags & UMA_ZONE_FIRSTTOUCH) != 0)
4541 		itemdomain = item_domain(item);
4542 #endif
4543 	critical_enter();
4544 	do {
4545 		cache = &zone->uz_cpu[curcpu];
4546 		/*
4547 		 * Try to free into the allocbucket first to give LIFO
4548 		 * ordering for cache-hot datastructures.  Spill over
4549 		 * into the freebucket if necessary.  Alloc will swap
4550 		 * them if one runs dry.
4551 		 */
4552 		bucket = &cache->uc_allocbucket;
4553 #ifdef NUMA
4554 		if ((uz_flags & UMA_ZONE_FIRSTTOUCH) != 0 &&
4555 		    PCPU_GET(domain) != itemdomain) {
4556 			bucket = &cache->uc_crossbucket;
4557 		} else
4558 #endif
4559 		if (bucket->ucb_cnt == bucket->ucb_entries &&
4560 		   cache->uc_freebucket.ucb_cnt <
4561 		   cache->uc_freebucket.ucb_entries)
4562 			cache_bucket_swap(&cache->uc_freebucket,
4563 			    &cache->uc_allocbucket);
4564 		if (__predict_true(bucket->ucb_cnt < bucket->ucb_entries)) {
4565 			cache_bucket_push(cache, bucket, item);
4566 			critical_exit();
4567 			return;
4568 		}
4569 	} while (cache_free(zone, cache, udata, itemdomain));
4570 	critical_exit();
4571 
4572 	/*
4573 	 * If nothing else caught this, we'll just do an internal free.
4574 	 */
4575 zfree_item:
4576 	zone_free_item(zone, item, udata, SKIP_DTOR);
4577 }
4578 
4579 #ifdef NUMA
4580 /*
4581  * sort crossdomain free buckets to domain correct buckets and cache
4582  * them.
4583  */
4584 static void
4585 zone_free_cross(uma_zone_t zone, uma_bucket_t bucket, void *udata)
4586 {
4587 	struct uma_bucketlist emptybuckets, fullbuckets;
4588 	uma_zone_domain_t zdom;
4589 	uma_bucket_t b;
4590 	smr_seq_t seq;
4591 	void *item;
4592 	int domain;
4593 
4594 	CTR3(KTR_UMA,
4595 	    "uma_zfree: zone %s(%p) draining cross bucket %p",
4596 	    zone->uz_name, zone, bucket);
4597 
4598 	/*
4599 	 * It is possible for buckets to arrive here out of order so we fetch
4600 	 * the current smr seq rather than accepting the bucket's.
4601 	 */
4602 	seq = SMR_SEQ_INVALID;
4603 	if ((zone->uz_flags & UMA_ZONE_SMR) != 0)
4604 		seq = smr_advance(zone->uz_smr);
4605 
4606 	/*
4607 	 * To avoid having ndomain * ndomain buckets for sorting we have a
4608 	 * lock on the current crossfree bucket.  A full matrix with
4609 	 * per-domain locking could be used if necessary.
4610 	 */
4611 	STAILQ_INIT(&emptybuckets);
4612 	STAILQ_INIT(&fullbuckets);
4613 	ZONE_CROSS_LOCK(zone);
4614 	for (; bucket->ub_cnt > 0; bucket->ub_cnt--) {
4615 		item = bucket->ub_bucket[bucket->ub_cnt - 1];
4616 		domain = item_domain(item);
4617 		zdom = ZDOM_GET(zone, domain);
4618 		if (zdom->uzd_cross == NULL) {
4619 			if ((b = STAILQ_FIRST(&emptybuckets)) != NULL) {
4620 				STAILQ_REMOVE_HEAD(&emptybuckets, ub_link);
4621 				zdom->uzd_cross = b;
4622 			} else {
4623 				/*
4624 				 * Avoid allocating a bucket with the cross lock
4625 				 * held, since allocation can trigger a
4626 				 * cross-domain free and bucket zones may
4627 				 * allocate from each other.
4628 				 */
4629 				ZONE_CROSS_UNLOCK(zone);
4630 				b = bucket_alloc(zone, udata, M_NOWAIT);
4631 				if (b == NULL)
4632 					goto out;
4633 				ZONE_CROSS_LOCK(zone);
4634 				if (zdom->uzd_cross != NULL) {
4635 					STAILQ_INSERT_HEAD(&emptybuckets, b,
4636 					    ub_link);
4637 				} else {
4638 					zdom->uzd_cross = b;
4639 				}
4640 			}
4641 		}
4642 		b = zdom->uzd_cross;
4643 		b->ub_bucket[b->ub_cnt++] = item;
4644 		b->ub_seq = seq;
4645 		if (b->ub_cnt == b->ub_entries) {
4646 			STAILQ_INSERT_HEAD(&fullbuckets, b, ub_link);
4647 			if ((b = STAILQ_FIRST(&emptybuckets)) != NULL)
4648 				STAILQ_REMOVE_HEAD(&emptybuckets, ub_link);
4649 			zdom->uzd_cross = b;
4650 		}
4651 	}
4652 	ZONE_CROSS_UNLOCK(zone);
4653 out:
4654 	if (bucket->ub_cnt == 0)
4655 		bucket->ub_seq = SMR_SEQ_INVALID;
4656 	bucket_free(zone, bucket, udata);
4657 
4658 	while ((b = STAILQ_FIRST(&emptybuckets)) != NULL) {
4659 		STAILQ_REMOVE_HEAD(&emptybuckets, ub_link);
4660 		bucket_free(zone, b, udata);
4661 	}
4662 	while ((b = STAILQ_FIRST(&fullbuckets)) != NULL) {
4663 		STAILQ_REMOVE_HEAD(&fullbuckets, ub_link);
4664 		domain = item_domain(b->ub_bucket[0]);
4665 		zone_put_bucket(zone, domain, b, udata, true);
4666 	}
4667 }
4668 #endif
4669 
4670 static void
4671 zone_free_bucket(uma_zone_t zone, uma_bucket_t bucket, void *udata,
4672     int itemdomain, bool ws)
4673 {
4674 
4675 #ifdef NUMA
4676 	/*
4677 	 * Buckets coming from the wrong domain will be entirely for the
4678 	 * only other domain on two domain systems.  In this case we can
4679 	 * simply cache them.  Otherwise we need to sort them back to
4680 	 * correct domains.
4681 	 */
4682 	if ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) != 0 &&
4683 	    vm_ndomains > 2 && PCPU_GET(domain) != itemdomain) {
4684 		zone_free_cross(zone, bucket, udata);
4685 		return;
4686 	}
4687 #endif
4688 
4689 	/*
4690 	 * Attempt to save the bucket in the zone's domain bucket cache.
4691 	 */
4692 	CTR3(KTR_UMA,
4693 	    "uma_zfree: zone %s(%p) putting bucket %p on free list",
4694 	    zone->uz_name, zone, bucket);
4695 	/* ub_cnt is pointing to the last free item */
4696 	if ((zone->uz_flags & UMA_ZONE_ROUNDROBIN) != 0)
4697 		itemdomain = zone_domain_lowest(zone, itemdomain);
4698 	zone_put_bucket(zone, itemdomain, bucket, udata, ws);
4699 }
4700 
4701 /*
4702  * Populate a free or cross bucket for the current cpu cache.  Free any
4703  * existing full bucket either to the zone cache or back to the slab layer.
4704  *
4705  * Enters and returns in a critical section.  false return indicates that
4706  * we can not satisfy this free in the cache layer.  true indicates that
4707  * the caller should retry.
4708  */
4709 static __noinline bool
4710 cache_free(uma_zone_t zone, uma_cache_t cache, void *udata, int itemdomain)
4711 {
4712 	uma_cache_bucket_t cbucket;
4713 	uma_bucket_t newbucket, bucket;
4714 
4715 	CRITICAL_ASSERT(curthread);
4716 
4717 	if (zone->uz_bucket_size == 0)
4718 		return false;
4719 
4720 	cache = &zone->uz_cpu[curcpu];
4721 	newbucket = NULL;
4722 
4723 	/*
4724 	 * FIRSTTOUCH domains need to free to the correct zdom.  When
4725 	 * enabled this is the zdom of the item.   The bucket is the
4726 	 * cross bucket if the current domain and itemdomain do not match.
4727 	 */
4728 	cbucket = &cache->uc_freebucket;
4729 #ifdef NUMA
4730 	if ((cache_uz_flags(cache) & UMA_ZONE_FIRSTTOUCH) != 0) {
4731 		if (PCPU_GET(domain) != itemdomain) {
4732 			cbucket = &cache->uc_crossbucket;
4733 			if (cbucket->ucb_cnt != 0)
4734 				counter_u64_add(zone->uz_xdomain,
4735 				    cbucket->ucb_cnt);
4736 		}
4737 	}
4738 #endif
4739 	bucket = cache_bucket_unload(cbucket);
4740 	KASSERT(bucket == NULL || bucket->ub_cnt == bucket->ub_entries,
4741 	    ("cache_free: Entered with non-full free bucket."));
4742 
4743 	/* We are no longer associated with this CPU. */
4744 	critical_exit();
4745 
4746 	/*
4747 	 * Don't let SMR zones operate without a free bucket.  Force
4748 	 * a synchronize and re-use this one.  We will only degrade
4749 	 * to a synchronize every bucket_size items rather than every
4750 	 * item if we fail to allocate a bucket.
4751 	 */
4752 	if ((zone->uz_flags & UMA_ZONE_SMR) != 0) {
4753 		if (bucket != NULL)
4754 			bucket->ub_seq = smr_advance(zone->uz_smr);
4755 		newbucket = bucket_alloc(zone, udata, M_NOWAIT);
4756 		if (newbucket == NULL && bucket != NULL) {
4757 			bucket_drain(zone, bucket);
4758 			newbucket = bucket;
4759 			bucket = NULL;
4760 		}
4761 	} else if (!bucketdisable)
4762 		newbucket = bucket_alloc(zone, udata, M_NOWAIT);
4763 
4764 	if (bucket != NULL)
4765 		zone_free_bucket(zone, bucket, udata, itemdomain, true);
4766 
4767 	critical_enter();
4768 	if ((bucket = newbucket) == NULL)
4769 		return (false);
4770 	cache = &zone->uz_cpu[curcpu];
4771 #ifdef NUMA
4772 	/*
4773 	 * Check to see if we should be populating the cross bucket.  If it
4774 	 * is already populated we will fall through and attempt to populate
4775 	 * the free bucket.
4776 	 */
4777 	if ((cache_uz_flags(cache) & UMA_ZONE_FIRSTTOUCH) != 0) {
4778 		if (PCPU_GET(domain) != itemdomain &&
4779 		    cache->uc_crossbucket.ucb_bucket == NULL) {
4780 			cache_bucket_load_cross(cache, bucket);
4781 			return (true);
4782 		}
4783 	}
4784 #endif
4785 	/*
4786 	 * We may have lost the race to fill the bucket or switched CPUs.
4787 	 */
4788 	if (cache->uc_freebucket.ucb_bucket != NULL) {
4789 		critical_exit();
4790 		bucket_free(zone, bucket, udata);
4791 		critical_enter();
4792 	} else
4793 		cache_bucket_load_free(cache, bucket);
4794 
4795 	return (true);
4796 }
4797 
4798 static void
4799 slab_free_item(uma_zone_t zone, uma_slab_t slab, void *item)
4800 {
4801 	uma_keg_t keg;
4802 	uma_domain_t dom;
4803 	int freei;
4804 
4805 	keg = zone->uz_keg;
4806 	KEG_LOCK_ASSERT(keg, slab->us_domain);
4807 
4808 	/* Do we need to remove from any lists? */
4809 	dom = &keg->uk_domain[slab->us_domain];
4810 	if (slab->us_freecount + 1 == keg->uk_ipers) {
4811 		LIST_REMOVE(slab, us_link);
4812 		LIST_INSERT_HEAD(&dom->ud_free_slab, slab, us_link);
4813 		dom->ud_free_slabs++;
4814 	} else if (slab->us_freecount == 0) {
4815 		LIST_REMOVE(slab, us_link);
4816 		LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
4817 	}
4818 
4819 	/* Slab management. */
4820 	freei = slab_item_index(slab, keg, item);
4821 	BIT_SET(keg->uk_ipers, freei, &slab->us_free);
4822 	slab->us_freecount++;
4823 
4824 	/* Keg statistics. */
4825 	dom->ud_free_items++;
4826 }
4827 
4828 static void
4829 zone_release(void *arg, void **bucket, int cnt)
4830 {
4831 	struct mtx *lock;
4832 	uma_zone_t zone;
4833 	uma_slab_t slab;
4834 	uma_keg_t keg;
4835 	uint8_t *mem;
4836 	void *item;
4837 	int i;
4838 
4839 	zone = arg;
4840 	keg = zone->uz_keg;
4841 	lock = NULL;
4842 	if (__predict_false((zone->uz_flags & UMA_ZFLAG_HASH) != 0))
4843 		lock = KEG_LOCK(keg, 0);
4844 	for (i = 0; i < cnt; i++) {
4845 		item = bucket[i];
4846 		if (__predict_true((zone->uz_flags & UMA_ZFLAG_VTOSLAB) != 0)) {
4847 			slab = vtoslab((vm_offset_t)item);
4848 		} else {
4849 			mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
4850 			if ((zone->uz_flags & UMA_ZFLAG_HASH) != 0)
4851 				slab = hash_sfind(&keg->uk_hash, mem);
4852 			else
4853 				slab = (uma_slab_t)(mem + keg->uk_pgoff);
4854 		}
4855 		if (lock != KEG_LOCKPTR(keg, slab->us_domain)) {
4856 			if (lock != NULL)
4857 				mtx_unlock(lock);
4858 			lock = KEG_LOCK(keg, slab->us_domain);
4859 		}
4860 		slab_free_item(zone, slab, item);
4861 	}
4862 	if (lock != NULL)
4863 		mtx_unlock(lock);
4864 }
4865 
4866 /*
4867  * Frees a single item to any zone.
4868  *
4869  * Arguments:
4870  *	zone   The zone to free to
4871  *	item   The item we're freeing
4872  *	udata  User supplied data for the dtor
4873  *	skip   Skip dtors and finis
4874  */
4875 static __noinline void
4876 zone_free_item(uma_zone_t zone, void *item, void *udata, enum zfreeskip skip)
4877 {
4878 
4879 	/*
4880 	 * If a free is sent directly to an SMR zone we have to
4881 	 * synchronize immediately because the item can instantly
4882 	 * be reallocated. This should only happen in degenerate
4883 	 * cases when no memory is available for per-cpu caches.
4884 	 */
4885 	if ((zone->uz_flags & UMA_ZONE_SMR) != 0 && skip == SKIP_NONE)
4886 		smr_synchronize(zone->uz_smr);
4887 
4888 	item_dtor(zone, item, zone->uz_size, udata, skip);
4889 
4890 	if (skip < SKIP_FINI && zone->uz_fini) {
4891 		kasan_mark_item_valid(zone, item);
4892 		zone->uz_fini(item, zone->uz_size);
4893 		kasan_mark_item_invalid(zone, item);
4894 	}
4895 
4896 	zone->uz_release(zone->uz_arg, &item, 1);
4897 
4898 	if (skip & SKIP_CNT)
4899 		return;
4900 
4901 	counter_u64_add(zone->uz_frees, 1);
4902 
4903 	if (zone->uz_max_items > 0)
4904 		zone_free_limit(zone, 1);
4905 }
4906 
4907 /* See uma.h */
4908 int
4909 uma_zone_set_max(uma_zone_t zone, int nitems)
4910 {
4911 
4912 	/*
4913 	 * If the limit is small, we may need to constrain the maximum per-CPU
4914 	 * cache size, or disable caching entirely.
4915 	 */
4916 	uma_zone_set_maxcache(zone, nitems);
4917 
4918 	/*
4919 	 * XXX This can misbehave if the zone has any allocations with
4920 	 * no limit and a limit is imposed.  There is currently no
4921 	 * way to clear a limit.
4922 	 */
4923 	ZONE_LOCK(zone);
4924 	if (zone->uz_max_items == 0)
4925 		ZONE_ASSERT_COLD(zone);
4926 	zone->uz_max_items = nitems;
4927 	zone->uz_flags |= UMA_ZFLAG_LIMIT;
4928 	zone_update_caches(zone);
4929 	/* We may need to wake waiters. */
4930 	wakeup(&zone->uz_max_items);
4931 	ZONE_UNLOCK(zone);
4932 
4933 	return (nitems);
4934 }
4935 
4936 /* See uma.h */
4937 void
4938 uma_zone_set_maxcache(uma_zone_t zone, int nitems)
4939 {
4940 	int bpcpu, bpdom, bsize, nb;
4941 
4942 	ZONE_LOCK(zone);
4943 
4944 	/*
4945 	 * Compute a lower bound on the number of items that may be cached in
4946 	 * the zone.  Each CPU gets at least two buckets, and for cross-domain
4947 	 * frees we use an additional bucket per CPU and per domain.  Select the
4948 	 * largest bucket size that does not exceed half of the requested limit,
4949 	 * with the left over space given to the full bucket cache.
4950 	 */
4951 	bpdom = 0;
4952 	bpcpu = 2;
4953 #ifdef NUMA
4954 	if ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) != 0 && vm_ndomains > 1) {
4955 		bpcpu++;
4956 		bpdom++;
4957 	}
4958 #endif
4959 	nb = bpcpu * mp_ncpus + bpdom * vm_ndomains;
4960 	bsize = nitems / nb / 2;
4961 	if (bsize > BUCKET_MAX)
4962 		bsize = BUCKET_MAX;
4963 	else if (bsize == 0 && nitems / nb > 0)
4964 		bsize = 1;
4965 	zone->uz_bucket_size_max = zone->uz_bucket_size = bsize;
4966 	if (zone->uz_bucket_size_min > zone->uz_bucket_size_max)
4967 		zone->uz_bucket_size_min = zone->uz_bucket_size_max;
4968 	zone->uz_bucket_max = nitems - nb * bsize;
4969 	ZONE_UNLOCK(zone);
4970 }
4971 
4972 /* See uma.h */
4973 int
4974 uma_zone_get_max(uma_zone_t zone)
4975 {
4976 	int nitems;
4977 
4978 	nitems = atomic_load_64(&zone->uz_max_items);
4979 
4980 	return (nitems);
4981 }
4982 
4983 /* See uma.h */
4984 void
4985 uma_zone_set_warning(uma_zone_t zone, const char *warning)
4986 {
4987 
4988 	ZONE_ASSERT_COLD(zone);
4989 	zone->uz_warning = warning;
4990 }
4991 
4992 /* See uma.h */
4993 void
4994 uma_zone_set_maxaction(uma_zone_t zone, uma_maxaction_t maxaction)
4995 {
4996 
4997 	ZONE_ASSERT_COLD(zone);
4998 	TASK_INIT(&zone->uz_maxaction, 0, (task_fn_t *)maxaction, zone);
4999 }
5000 
5001 /* See uma.h */
5002 int
5003 uma_zone_get_cur(uma_zone_t zone)
5004 {
5005 	int64_t nitems;
5006 	u_int i;
5007 
5008 	nitems = 0;
5009 	if (zone->uz_allocs != EARLY_COUNTER && zone->uz_frees != EARLY_COUNTER)
5010 		nitems = counter_u64_fetch(zone->uz_allocs) -
5011 		    counter_u64_fetch(zone->uz_frees);
5012 	CPU_FOREACH(i)
5013 		nitems += atomic_load_64(&zone->uz_cpu[i].uc_allocs) -
5014 		    atomic_load_64(&zone->uz_cpu[i].uc_frees);
5015 
5016 	return (nitems < 0 ? 0 : nitems);
5017 }
5018 
5019 static uint64_t
5020 uma_zone_get_allocs(uma_zone_t zone)
5021 {
5022 	uint64_t nitems;
5023 	u_int i;
5024 
5025 	nitems = 0;
5026 	if (zone->uz_allocs != EARLY_COUNTER)
5027 		nitems = counter_u64_fetch(zone->uz_allocs);
5028 	CPU_FOREACH(i)
5029 		nitems += atomic_load_64(&zone->uz_cpu[i].uc_allocs);
5030 
5031 	return (nitems);
5032 }
5033 
5034 static uint64_t
5035 uma_zone_get_frees(uma_zone_t zone)
5036 {
5037 	uint64_t nitems;
5038 	u_int i;
5039 
5040 	nitems = 0;
5041 	if (zone->uz_frees != EARLY_COUNTER)
5042 		nitems = counter_u64_fetch(zone->uz_frees);
5043 	CPU_FOREACH(i)
5044 		nitems += atomic_load_64(&zone->uz_cpu[i].uc_frees);
5045 
5046 	return (nitems);
5047 }
5048 
5049 #ifdef INVARIANTS
5050 /* Used only for KEG_ASSERT_COLD(). */
5051 static uint64_t
5052 uma_keg_get_allocs(uma_keg_t keg)
5053 {
5054 	uma_zone_t z;
5055 	uint64_t nitems;
5056 
5057 	nitems = 0;
5058 	LIST_FOREACH(z, &keg->uk_zones, uz_link)
5059 		nitems += uma_zone_get_allocs(z);
5060 
5061 	return (nitems);
5062 }
5063 #endif
5064 
5065 /* See uma.h */
5066 void
5067 uma_zone_set_init(uma_zone_t zone, uma_init uminit)
5068 {
5069 	uma_keg_t keg;
5070 
5071 	KEG_GET(zone, keg);
5072 	KEG_ASSERT_COLD(keg);
5073 	keg->uk_init = uminit;
5074 }
5075 
5076 /* See uma.h */
5077 void
5078 uma_zone_set_fini(uma_zone_t zone, uma_fini fini)
5079 {
5080 	uma_keg_t keg;
5081 
5082 	KEG_GET(zone, keg);
5083 	KEG_ASSERT_COLD(keg);
5084 	keg->uk_fini = fini;
5085 }
5086 
5087 /* See uma.h */
5088 void
5089 uma_zone_set_zinit(uma_zone_t zone, uma_init zinit)
5090 {
5091 
5092 	ZONE_ASSERT_COLD(zone);
5093 	zone->uz_init = zinit;
5094 }
5095 
5096 /* See uma.h */
5097 void
5098 uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini)
5099 {
5100 
5101 	ZONE_ASSERT_COLD(zone);
5102 	zone->uz_fini = zfini;
5103 }
5104 
5105 /* See uma.h */
5106 void
5107 uma_zone_set_freef(uma_zone_t zone, uma_free freef)
5108 {
5109 	uma_keg_t keg;
5110 
5111 	KEG_GET(zone, keg);
5112 	KEG_ASSERT_COLD(keg);
5113 	keg->uk_freef = freef;
5114 }
5115 
5116 /* See uma.h */
5117 void
5118 uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf)
5119 {
5120 	uma_keg_t keg;
5121 
5122 	KEG_GET(zone, keg);
5123 	KEG_ASSERT_COLD(keg);
5124 	keg->uk_allocf = allocf;
5125 }
5126 
5127 /* See uma.h */
5128 void
5129 uma_zone_set_smr(uma_zone_t zone, smr_t smr)
5130 {
5131 
5132 	ZONE_ASSERT_COLD(zone);
5133 
5134 	KASSERT(smr != NULL, ("Got NULL smr"));
5135 	KASSERT((zone->uz_flags & UMA_ZONE_SMR) == 0,
5136 	    ("zone %p (%s) already uses SMR", zone, zone->uz_name));
5137 	zone->uz_flags |= UMA_ZONE_SMR;
5138 	zone->uz_smr = smr;
5139 	zone_update_caches(zone);
5140 }
5141 
5142 smr_t
5143 uma_zone_get_smr(uma_zone_t zone)
5144 {
5145 
5146 	return (zone->uz_smr);
5147 }
5148 
5149 /* See uma.h */
5150 void
5151 uma_zone_reserve(uma_zone_t zone, int items)
5152 {
5153 	uma_keg_t keg;
5154 
5155 	KEG_GET(zone, keg);
5156 	KEG_ASSERT_COLD(keg);
5157 	keg->uk_reserve = items;
5158 }
5159 
5160 /* See uma.h */
5161 int
5162 uma_zone_reserve_kva(uma_zone_t zone, int count)
5163 {
5164 	uma_keg_t keg;
5165 	vm_offset_t kva;
5166 	u_int pages;
5167 
5168 	KEG_GET(zone, keg);
5169 	KEG_ASSERT_COLD(keg);
5170 	ZONE_ASSERT_COLD(zone);
5171 
5172 	pages = howmany(count, keg->uk_ipers) * keg->uk_ppera;
5173 
5174 #ifdef UMA_MD_SMALL_ALLOC
5175 	if (keg->uk_ppera > 1) {
5176 #else
5177 	if (1) {
5178 #endif
5179 		kva = kva_alloc((vm_size_t)pages * PAGE_SIZE);
5180 		if (kva == 0)
5181 			return (0);
5182 	} else
5183 		kva = 0;
5184 
5185 	MPASS(keg->uk_kva == 0);
5186 	keg->uk_kva = kva;
5187 	keg->uk_offset = 0;
5188 	zone->uz_max_items = pages * keg->uk_ipers;
5189 #ifdef UMA_MD_SMALL_ALLOC
5190 	keg->uk_allocf = (keg->uk_ppera > 1) ? noobj_alloc : uma_small_alloc;
5191 #else
5192 	keg->uk_allocf = noobj_alloc;
5193 #endif
5194 	keg->uk_flags |= UMA_ZFLAG_LIMIT | UMA_ZONE_NOFREE;
5195 	zone->uz_flags |= UMA_ZFLAG_LIMIT | UMA_ZONE_NOFREE;
5196 	zone_update_caches(zone);
5197 
5198 	return (1);
5199 }
5200 
5201 /* See uma.h */
5202 void
5203 uma_prealloc(uma_zone_t zone, int items)
5204 {
5205 	struct vm_domainset_iter di;
5206 	uma_domain_t dom;
5207 	uma_slab_t slab;
5208 	uma_keg_t keg;
5209 	int aflags, domain, slabs;
5210 
5211 	KEG_GET(zone, keg);
5212 	slabs = howmany(items, keg->uk_ipers);
5213 	while (slabs-- > 0) {
5214 		aflags = M_NOWAIT;
5215 		vm_domainset_iter_policy_ref_init(&di, &keg->uk_dr, &domain,
5216 		    &aflags);
5217 		for (;;) {
5218 			slab = keg_alloc_slab(keg, zone, domain, M_WAITOK,
5219 			    aflags);
5220 			if (slab != NULL) {
5221 				dom = &keg->uk_domain[slab->us_domain];
5222 				/*
5223 				 * keg_alloc_slab() always returns a slab on the
5224 				 * partial list.
5225 				 */
5226 				LIST_REMOVE(slab, us_link);
5227 				LIST_INSERT_HEAD(&dom->ud_free_slab, slab,
5228 				    us_link);
5229 				dom->ud_free_slabs++;
5230 				KEG_UNLOCK(keg, slab->us_domain);
5231 				break;
5232 			}
5233 			if (vm_domainset_iter_policy(&di, &domain) != 0)
5234 				vm_wait_doms(&keg->uk_dr.dr_policy->ds_mask, 0);
5235 		}
5236 	}
5237 }
5238 
5239 /*
5240  * Returns a snapshot of memory consumption in bytes.
5241  */
5242 size_t
5243 uma_zone_memory(uma_zone_t zone)
5244 {
5245 	size_t sz;
5246 	int i;
5247 
5248 	sz = 0;
5249 	if (zone->uz_flags & UMA_ZFLAG_CACHE) {
5250 		for (i = 0; i < vm_ndomains; i++)
5251 			sz += ZDOM_GET(zone, i)->uzd_nitems;
5252 		return (sz * zone->uz_size);
5253 	}
5254 	for (i = 0; i < vm_ndomains; i++)
5255 		sz += zone->uz_keg->uk_domain[i].ud_pages;
5256 
5257 	return (sz * PAGE_SIZE);
5258 }
5259 
5260 struct uma_reclaim_args {
5261 	int	domain;
5262 	int	req;
5263 };
5264 
5265 static void
5266 uma_reclaim_domain_cb(uma_zone_t zone, void *arg)
5267 {
5268 	struct uma_reclaim_args *args;
5269 
5270 	args = arg;
5271 	if ((zone->uz_flags & UMA_ZONE_UNMANAGED) == 0)
5272 		uma_zone_reclaim_domain(zone, args->req, args->domain);
5273 }
5274 
5275 /* See uma.h */
5276 void
5277 uma_reclaim(int req)
5278 {
5279 	uma_reclaim_domain(req, UMA_ANYDOMAIN);
5280 }
5281 
5282 void
5283 uma_reclaim_domain(int req, int domain)
5284 {
5285 	struct uma_reclaim_args args;
5286 
5287 	bucket_enable();
5288 
5289 	args.domain = domain;
5290 	args.req = req;
5291 
5292 	sx_slock(&uma_reclaim_lock);
5293 	switch (req) {
5294 	case UMA_RECLAIM_TRIM:
5295 	case UMA_RECLAIM_DRAIN:
5296 		zone_foreach(uma_reclaim_domain_cb, &args);
5297 		break;
5298 	case UMA_RECLAIM_DRAIN_CPU:
5299 		zone_foreach(uma_reclaim_domain_cb, &args);
5300 		pcpu_cache_drain_safe(NULL);
5301 		zone_foreach(uma_reclaim_domain_cb, &args);
5302 		break;
5303 	default:
5304 		panic("unhandled reclamation request %d", req);
5305 	}
5306 
5307 	/*
5308 	 * Some slabs may have been freed but this zone will be visited early
5309 	 * we visit again so that we can free pages that are empty once other
5310 	 * zones are drained.  We have to do the same for buckets.
5311 	 */
5312 	uma_zone_reclaim_domain(slabzones[0], UMA_RECLAIM_DRAIN, domain);
5313 	uma_zone_reclaim_domain(slabzones[1], UMA_RECLAIM_DRAIN, domain);
5314 	bucket_zone_drain(domain);
5315 	sx_sunlock(&uma_reclaim_lock);
5316 }
5317 
5318 static volatile int uma_reclaim_needed;
5319 
5320 void
5321 uma_reclaim_wakeup(void)
5322 {
5323 
5324 	if (atomic_fetchadd_int(&uma_reclaim_needed, 1) == 0)
5325 		wakeup(uma_reclaim);
5326 }
5327 
5328 void
5329 uma_reclaim_worker(void *arg __unused)
5330 {
5331 
5332 	for (;;) {
5333 		sx_xlock(&uma_reclaim_lock);
5334 		while (atomic_load_int(&uma_reclaim_needed) == 0)
5335 			sx_sleep(uma_reclaim, &uma_reclaim_lock, PVM, "umarcl",
5336 			    hz);
5337 		sx_xunlock(&uma_reclaim_lock);
5338 		EVENTHANDLER_INVOKE(vm_lowmem, VM_LOW_KMEM);
5339 		uma_reclaim(UMA_RECLAIM_DRAIN_CPU);
5340 		atomic_store_int(&uma_reclaim_needed, 0);
5341 		/* Don't fire more than once per-second. */
5342 		pause("umarclslp", hz);
5343 	}
5344 }
5345 
5346 /* See uma.h */
5347 void
5348 uma_zone_reclaim(uma_zone_t zone, int req)
5349 {
5350 	uma_zone_reclaim_domain(zone, req, UMA_ANYDOMAIN);
5351 }
5352 
5353 void
5354 uma_zone_reclaim_domain(uma_zone_t zone, int req, int domain)
5355 {
5356 	switch (req) {
5357 	case UMA_RECLAIM_TRIM:
5358 		zone_reclaim(zone, domain, M_NOWAIT, false);
5359 		break;
5360 	case UMA_RECLAIM_DRAIN:
5361 		zone_reclaim(zone, domain, M_NOWAIT, true);
5362 		break;
5363 	case UMA_RECLAIM_DRAIN_CPU:
5364 		pcpu_cache_drain_safe(zone);
5365 		zone_reclaim(zone, domain, M_NOWAIT, true);
5366 		break;
5367 	default:
5368 		panic("unhandled reclamation request %d", req);
5369 	}
5370 }
5371 
5372 /* See uma.h */
5373 int
5374 uma_zone_exhausted(uma_zone_t zone)
5375 {
5376 
5377 	return (atomic_load_32(&zone->uz_sleepers) > 0);
5378 }
5379 
5380 unsigned long
5381 uma_limit(void)
5382 {
5383 
5384 	return (uma_kmem_limit);
5385 }
5386 
5387 void
5388 uma_set_limit(unsigned long limit)
5389 {
5390 
5391 	uma_kmem_limit = limit;
5392 }
5393 
5394 unsigned long
5395 uma_size(void)
5396 {
5397 
5398 	return (atomic_load_long(&uma_kmem_total));
5399 }
5400 
5401 long
5402 uma_avail(void)
5403 {
5404 
5405 	return (uma_kmem_limit - uma_size());
5406 }
5407 
5408 #ifdef DDB
5409 /*
5410  * Generate statistics across both the zone and its per-cpu cache's.  Return
5411  * desired statistics if the pointer is non-NULL for that statistic.
5412  *
5413  * Note: does not update the zone statistics, as it can't safely clear the
5414  * per-CPU cache statistic.
5415  *
5416  */
5417 static void
5418 uma_zone_sumstat(uma_zone_t z, long *cachefreep, uint64_t *allocsp,
5419     uint64_t *freesp, uint64_t *sleepsp, uint64_t *xdomainp)
5420 {
5421 	uma_cache_t cache;
5422 	uint64_t allocs, frees, sleeps, xdomain;
5423 	int cachefree, cpu;
5424 
5425 	allocs = frees = sleeps = xdomain = 0;
5426 	cachefree = 0;
5427 	CPU_FOREACH(cpu) {
5428 		cache = &z->uz_cpu[cpu];
5429 		cachefree += cache->uc_allocbucket.ucb_cnt;
5430 		cachefree += cache->uc_freebucket.ucb_cnt;
5431 		xdomain += cache->uc_crossbucket.ucb_cnt;
5432 		cachefree += cache->uc_crossbucket.ucb_cnt;
5433 		allocs += cache->uc_allocs;
5434 		frees += cache->uc_frees;
5435 	}
5436 	allocs += counter_u64_fetch(z->uz_allocs);
5437 	frees += counter_u64_fetch(z->uz_frees);
5438 	xdomain += counter_u64_fetch(z->uz_xdomain);
5439 	sleeps += z->uz_sleeps;
5440 	if (cachefreep != NULL)
5441 		*cachefreep = cachefree;
5442 	if (allocsp != NULL)
5443 		*allocsp = allocs;
5444 	if (freesp != NULL)
5445 		*freesp = frees;
5446 	if (sleepsp != NULL)
5447 		*sleepsp = sleeps;
5448 	if (xdomainp != NULL)
5449 		*xdomainp = xdomain;
5450 }
5451 #endif /* DDB */
5452 
5453 static int
5454 sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS)
5455 {
5456 	uma_keg_t kz;
5457 	uma_zone_t z;
5458 	int count;
5459 
5460 	count = 0;
5461 	rw_rlock(&uma_rwlock);
5462 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
5463 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
5464 			count++;
5465 	}
5466 	LIST_FOREACH(z, &uma_cachezones, uz_link)
5467 		count++;
5468 
5469 	rw_runlock(&uma_rwlock);
5470 	return (sysctl_handle_int(oidp, &count, 0, req));
5471 }
5472 
5473 static void
5474 uma_vm_zone_stats(struct uma_type_header *uth, uma_zone_t z, struct sbuf *sbuf,
5475     struct uma_percpu_stat *ups, bool internal)
5476 {
5477 	uma_zone_domain_t zdom;
5478 	uma_cache_t cache;
5479 	int i;
5480 
5481 	for (i = 0; i < vm_ndomains; i++) {
5482 		zdom = ZDOM_GET(z, i);
5483 		uth->uth_zone_free += zdom->uzd_nitems;
5484 	}
5485 	uth->uth_allocs = counter_u64_fetch(z->uz_allocs);
5486 	uth->uth_frees = counter_u64_fetch(z->uz_frees);
5487 	uth->uth_fails = counter_u64_fetch(z->uz_fails);
5488 	uth->uth_xdomain = counter_u64_fetch(z->uz_xdomain);
5489 	uth->uth_sleeps = z->uz_sleeps;
5490 
5491 	for (i = 0; i < mp_maxid + 1; i++) {
5492 		bzero(&ups[i], sizeof(*ups));
5493 		if (internal || CPU_ABSENT(i))
5494 			continue;
5495 		cache = &z->uz_cpu[i];
5496 		ups[i].ups_cache_free += cache->uc_allocbucket.ucb_cnt;
5497 		ups[i].ups_cache_free += cache->uc_freebucket.ucb_cnt;
5498 		ups[i].ups_cache_free += cache->uc_crossbucket.ucb_cnt;
5499 		ups[i].ups_allocs = cache->uc_allocs;
5500 		ups[i].ups_frees = cache->uc_frees;
5501 	}
5502 }
5503 
5504 static int
5505 sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS)
5506 {
5507 	struct uma_stream_header ush;
5508 	struct uma_type_header uth;
5509 	struct uma_percpu_stat *ups;
5510 	struct sbuf sbuf;
5511 	uma_keg_t kz;
5512 	uma_zone_t z;
5513 	uint64_t items;
5514 	uint32_t kfree, pages;
5515 	int count, error, i;
5516 
5517 	error = sysctl_wire_old_buffer(req, 0);
5518 	if (error != 0)
5519 		return (error);
5520 	sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
5521 	sbuf_clear_flags(&sbuf, SBUF_INCLUDENUL);
5522 	ups = malloc((mp_maxid + 1) * sizeof(*ups), M_TEMP, M_WAITOK);
5523 
5524 	count = 0;
5525 	rw_rlock(&uma_rwlock);
5526 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
5527 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
5528 			count++;
5529 	}
5530 
5531 	LIST_FOREACH(z, &uma_cachezones, uz_link)
5532 		count++;
5533 
5534 	/*
5535 	 * Insert stream header.
5536 	 */
5537 	bzero(&ush, sizeof(ush));
5538 	ush.ush_version = UMA_STREAM_VERSION;
5539 	ush.ush_maxcpus = (mp_maxid + 1);
5540 	ush.ush_count = count;
5541 	(void)sbuf_bcat(&sbuf, &ush, sizeof(ush));
5542 
5543 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
5544 		kfree = pages = 0;
5545 		for (i = 0; i < vm_ndomains; i++) {
5546 			kfree += kz->uk_domain[i].ud_free_items;
5547 			pages += kz->uk_domain[i].ud_pages;
5548 		}
5549 		LIST_FOREACH(z, &kz->uk_zones, uz_link) {
5550 			bzero(&uth, sizeof(uth));
5551 			strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
5552 			uth.uth_align = kz->uk_align;
5553 			uth.uth_size = kz->uk_size;
5554 			uth.uth_rsize = kz->uk_rsize;
5555 			if (z->uz_max_items > 0) {
5556 				items = UZ_ITEMS_COUNT(z->uz_items);
5557 				uth.uth_pages = (items / kz->uk_ipers) *
5558 					kz->uk_ppera;
5559 			} else
5560 				uth.uth_pages = pages;
5561 			uth.uth_maxpages = (z->uz_max_items / kz->uk_ipers) *
5562 			    kz->uk_ppera;
5563 			uth.uth_limit = z->uz_max_items;
5564 			uth.uth_keg_free = kfree;
5565 
5566 			/*
5567 			 * A zone is secondary is it is not the first entry
5568 			 * on the keg's zone list.
5569 			 */
5570 			if ((z->uz_flags & UMA_ZONE_SECONDARY) &&
5571 			    (LIST_FIRST(&kz->uk_zones) != z))
5572 				uth.uth_zone_flags = UTH_ZONE_SECONDARY;
5573 			uma_vm_zone_stats(&uth, z, &sbuf, ups,
5574 			    kz->uk_flags & UMA_ZFLAG_INTERNAL);
5575 			(void)sbuf_bcat(&sbuf, &uth, sizeof(uth));
5576 			for (i = 0; i < mp_maxid + 1; i++)
5577 				(void)sbuf_bcat(&sbuf, &ups[i], sizeof(ups[i]));
5578 		}
5579 	}
5580 	LIST_FOREACH(z, &uma_cachezones, uz_link) {
5581 		bzero(&uth, sizeof(uth));
5582 		strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
5583 		uth.uth_size = z->uz_size;
5584 		uma_vm_zone_stats(&uth, z, &sbuf, ups, false);
5585 		(void)sbuf_bcat(&sbuf, &uth, sizeof(uth));
5586 		for (i = 0; i < mp_maxid + 1; i++)
5587 			(void)sbuf_bcat(&sbuf, &ups[i], sizeof(ups[i]));
5588 	}
5589 
5590 	rw_runlock(&uma_rwlock);
5591 	error = sbuf_finish(&sbuf);
5592 	sbuf_delete(&sbuf);
5593 	free(ups, M_TEMP);
5594 	return (error);
5595 }
5596 
5597 int
5598 sysctl_handle_uma_zone_max(SYSCTL_HANDLER_ARGS)
5599 {
5600 	uma_zone_t zone = *(uma_zone_t *)arg1;
5601 	int error, max;
5602 
5603 	max = uma_zone_get_max(zone);
5604 	error = sysctl_handle_int(oidp, &max, 0, req);
5605 	if (error || !req->newptr)
5606 		return (error);
5607 
5608 	uma_zone_set_max(zone, max);
5609 
5610 	return (0);
5611 }
5612 
5613 int
5614 sysctl_handle_uma_zone_cur(SYSCTL_HANDLER_ARGS)
5615 {
5616 	uma_zone_t zone;
5617 	int cur;
5618 
5619 	/*
5620 	 * Some callers want to add sysctls for global zones that
5621 	 * may not yet exist so they pass a pointer to a pointer.
5622 	 */
5623 	if (arg2 == 0)
5624 		zone = *(uma_zone_t *)arg1;
5625 	else
5626 		zone = arg1;
5627 	cur = uma_zone_get_cur(zone);
5628 	return (sysctl_handle_int(oidp, &cur, 0, req));
5629 }
5630 
5631 static int
5632 sysctl_handle_uma_zone_allocs(SYSCTL_HANDLER_ARGS)
5633 {
5634 	uma_zone_t zone = arg1;
5635 	uint64_t cur;
5636 
5637 	cur = uma_zone_get_allocs(zone);
5638 	return (sysctl_handle_64(oidp, &cur, 0, req));
5639 }
5640 
5641 static int
5642 sysctl_handle_uma_zone_frees(SYSCTL_HANDLER_ARGS)
5643 {
5644 	uma_zone_t zone = arg1;
5645 	uint64_t cur;
5646 
5647 	cur = uma_zone_get_frees(zone);
5648 	return (sysctl_handle_64(oidp, &cur, 0, req));
5649 }
5650 
5651 static int
5652 sysctl_handle_uma_zone_flags(SYSCTL_HANDLER_ARGS)
5653 {
5654 	struct sbuf sbuf;
5655 	uma_zone_t zone = arg1;
5656 	int error;
5657 
5658 	sbuf_new_for_sysctl(&sbuf, NULL, 0, req);
5659 	if (zone->uz_flags != 0)
5660 		sbuf_printf(&sbuf, "0x%b", zone->uz_flags, PRINT_UMA_ZFLAGS);
5661 	else
5662 		sbuf_printf(&sbuf, "0");
5663 	error = sbuf_finish(&sbuf);
5664 	sbuf_delete(&sbuf);
5665 
5666 	return (error);
5667 }
5668 
5669 static int
5670 sysctl_handle_uma_slab_efficiency(SYSCTL_HANDLER_ARGS)
5671 {
5672 	uma_keg_t keg = arg1;
5673 	int avail, effpct, total;
5674 
5675 	total = keg->uk_ppera * PAGE_SIZE;
5676 	if ((keg->uk_flags & UMA_ZFLAG_OFFPAGE) != 0)
5677 		total += slabzone(keg->uk_ipers)->uz_keg->uk_rsize;
5678 	/*
5679 	 * We consider the client's requested size and alignment here, not the
5680 	 * real size determination uk_rsize, because we also adjust the real
5681 	 * size for internal implementation reasons (max bitset size).
5682 	 */
5683 	avail = keg->uk_ipers * roundup2(keg->uk_size, keg->uk_align + 1);
5684 	if ((keg->uk_flags & UMA_ZONE_PCPU) != 0)
5685 		avail *= mp_maxid + 1;
5686 	effpct = 100 * avail / total;
5687 	return (sysctl_handle_int(oidp, &effpct, 0, req));
5688 }
5689 
5690 static int
5691 sysctl_handle_uma_zone_items(SYSCTL_HANDLER_ARGS)
5692 {
5693 	uma_zone_t zone = arg1;
5694 	uint64_t cur;
5695 
5696 	cur = UZ_ITEMS_COUNT(atomic_load_64(&zone->uz_items));
5697 	return (sysctl_handle_64(oidp, &cur, 0, req));
5698 }
5699 
5700 #ifdef INVARIANTS
5701 static uma_slab_t
5702 uma_dbg_getslab(uma_zone_t zone, void *item)
5703 {
5704 	uma_slab_t slab;
5705 	uma_keg_t keg;
5706 	uint8_t *mem;
5707 
5708 	/*
5709 	 * It is safe to return the slab here even though the
5710 	 * zone is unlocked because the item's allocation state
5711 	 * essentially holds a reference.
5712 	 */
5713 	mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
5714 	if ((zone->uz_flags & UMA_ZFLAG_CACHE) != 0)
5715 		return (NULL);
5716 	if (zone->uz_flags & UMA_ZFLAG_VTOSLAB)
5717 		return (vtoslab((vm_offset_t)mem));
5718 	keg = zone->uz_keg;
5719 	if ((keg->uk_flags & UMA_ZFLAG_HASH) == 0)
5720 		return ((uma_slab_t)(mem + keg->uk_pgoff));
5721 	KEG_LOCK(keg, 0);
5722 	slab = hash_sfind(&keg->uk_hash, mem);
5723 	KEG_UNLOCK(keg, 0);
5724 
5725 	return (slab);
5726 }
5727 
5728 static bool
5729 uma_dbg_zskip(uma_zone_t zone, void *mem)
5730 {
5731 
5732 	if ((zone->uz_flags & UMA_ZFLAG_CACHE) != 0)
5733 		return (true);
5734 
5735 	return (uma_dbg_kskip(zone->uz_keg, mem));
5736 }
5737 
5738 static bool
5739 uma_dbg_kskip(uma_keg_t keg, void *mem)
5740 {
5741 	uintptr_t idx;
5742 
5743 	if (dbg_divisor == 0)
5744 		return (true);
5745 
5746 	if (dbg_divisor == 1)
5747 		return (false);
5748 
5749 	idx = (uintptr_t)mem >> PAGE_SHIFT;
5750 	if (keg->uk_ipers > 1) {
5751 		idx *= keg->uk_ipers;
5752 		idx += ((uintptr_t)mem & PAGE_MASK) / keg->uk_rsize;
5753 	}
5754 
5755 	if ((idx / dbg_divisor) * dbg_divisor != idx) {
5756 		counter_u64_add(uma_skip_cnt, 1);
5757 		return (true);
5758 	}
5759 	counter_u64_add(uma_dbg_cnt, 1);
5760 
5761 	return (false);
5762 }
5763 
5764 /*
5765  * Set up the slab's freei data such that uma_dbg_free can function.
5766  *
5767  */
5768 static void
5769 uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item)
5770 {
5771 	uma_keg_t keg;
5772 	int freei;
5773 
5774 	if (slab == NULL) {
5775 		slab = uma_dbg_getslab(zone, item);
5776 		if (slab == NULL)
5777 			panic("uma: item %p did not belong to zone %s",
5778 			    item, zone->uz_name);
5779 	}
5780 	keg = zone->uz_keg;
5781 	freei = slab_item_index(slab, keg, item);
5782 
5783 	if (BIT_TEST_SET_ATOMIC(keg->uk_ipers, freei,
5784 	    slab_dbg_bits(slab, keg)))
5785 		panic("Duplicate alloc of %p from zone %p(%s) slab %p(%d)",
5786 		    item, zone, zone->uz_name, slab, freei);
5787 }
5788 
5789 /*
5790  * Verifies freed addresses.  Checks for alignment, valid slab membership
5791  * and duplicate frees.
5792  *
5793  */
5794 static void
5795 uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item)
5796 {
5797 	uma_keg_t keg;
5798 	int freei;
5799 
5800 	if (slab == NULL) {
5801 		slab = uma_dbg_getslab(zone, item);
5802 		if (slab == NULL)
5803 			panic("uma: Freed item %p did not belong to zone %s",
5804 			    item, zone->uz_name);
5805 	}
5806 	keg = zone->uz_keg;
5807 	freei = slab_item_index(slab, keg, item);
5808 
5809 	if (freei >= keg->uk_ipers)
5810 		panic("Invalid free of %p from zone %p(%s) slab %p(%d)",
5811 		    item, zone, zone->uz_name, slab, freei);
5812 
5813 	if (slab_item(slab, keg, freei) != item)
5814 		panic("Unaligned free of %p from zone %p(%s) slab %p(%d)",
5815 		    item, zone, zone->uz_name, slab, freei);
5816 
5817 	if (!BIT_TEST_CLR_ATOMIC(keg->uk_ipers, freei,
5818 	    slab_dbg_bits(slab, keg)))
5819 		panic("Duplicate free of %p from zone %p(%s) slab %p(%d)",
5820 		    item, zone, zone->uz_name, slab, freei);
5821 }
5822 #endif /* INVARIANTS */
5823 
5824 #ifdef DDB
5825 static int64_t
5826 get_uma_stats(uma_keg_t kz, uma_zone_t z, uint64_t *allocs, uint64_t *used,
5827     uint64_t *sleeps, long *cachefree, uint64_t *xdomain)
5828 {
5829 	uint64_t frees;
5830 	int i;
5831 
5832 	if (kz->uk_flags & UMA_ZFLAG_INTERNAL) {
5833 		*allocs = counter_u64_fetch(z->uz_allocs);
5834 		frees = counter_u64_fetch(z->uz_frees);
5835 		*sleeps = z->uz_sleeps;
5836 		*cachefree = 0;
5837 		*xdomain = 0;
5838 	} else
5839 		uma_zone_sumstat(z, cachefree, allocs, &frees, sleeps,
5840 		    xdomain);
5841 	for (i = 0; i < vm_ndomains; i++) {
5842 		*cachefree += ZDOM_GET(z, i)->uzd_nitems;
5843 		if (!((z->uz_flags & UMA_ZONE_SECONDARY) &&
5844 		    (LIST_FIRST(&kz->uk_zones) != z)))
5845 			*cachefree += kz->uk_domain[i].ud_free_items;
5846 	}
5847 	*used = *allocs - frees;
5848 	return (((int64_t)*used + *cachefree) * kz->uk_size);
5849 }
5850 
5851 DB_SHOW_COMMAND_FLAGS(uma, db_show_uma, DB_CMD_MEMSAFE)
5852 {
5853 	const char *fmt_hdr, *fmt_entry;
5854 	uma_keg_t kz;
5855 	uma_zone_t z;
5856 	uint64_t allocs, used, sleeps, xdomain;
5857 	long cachefree;
5858 	/* variables for sorting */
5859 	uma_keg_t cur_keg;
5860 	uma_zone_t cur_zone, last_zone;
5861 	int64_t cur_size, last_size, size;
5862 	int ties;
5863 
5864 	/* /i option produces machine-parseable CSV output */
5865 	if (modif[0] == 'i') {
5866 		fmt_hdr = "%s,%s,%s,%s,%s,%s,%s,%s,%s\n";
5867 		fmt_entry = "\"%s\",%ju,%jd,%ld,%ju,%ju,%u,%jd,%ju\n";
5868 	} else {
5869 		fmt_hdr = "%18s %6s %7s %7s %11s %7s %7s %10s %8s\n";
5870 		fmt_entry = "%18s %6ju %7jd %7ld %11ju %7ju %7u %10jd %8ju\n";
5871 	}
5872 
5873 	db_printf(fmt_hdr, "Zone", "Size", "Used", "Free", "Requests",
5874 	    "Sleeps", "Bucket", "Total Mem", "XFree");
5875 
5876 	/* Sort the zones with largest size first. */
5877 	last_zone = NULL;
5878 	last_size = INT64_MAX;
5879 	for (;;) {
5880 		cur_zone = NULL;
5881 		cur_size = -1;
5882 		ties = 0;
5883 		LIST_FOREACH(kz, &uma_kegs, uk_link) {
5884 			LIST_FOREACH(z, &kz->uk_zones, uz_link) {
5885 				/*
5886 				 * In the case of size ties, print out zones
5887 				 * in the order they are encountered.  That is,
5888 				 * when we encounter the most recently output
5889 				 * zone, we have already printed all preceding
5890 				 * ties, and we must print all following ties.
5891 				 */
5892 				if (z == last_zone) {
5893 					ties = 1;
5894 					continue;
5895 				}
5896 				size = get_uma_stats(kz, z, &allocs, &used,
5897 				    &sleeps, &cachefree, &xdomain);
5898 				if (size > cur_size && size < last_size + ties)
5899 				{
5900 					cur_size = size;
5901 					cur_zone = z;
5902 					cur_keg = kz;
5903 				}
5904 			}
5905 		}
5906 		if (cur_zone == NULL)
5907 			break;
5908 
5909 		size = get_uma_stats(cur_keg, cur_zone, &allocs, &used,
5910 		    &sleeps, &cachefree, &xdomain);
5911 		db_printf(fmt_entry, cur_zone->uz_name,
5912 		    (uintmax_t)cur_keg->uk_size, (intmax_t)used, cachefree,
5913 		    (uintmax_t)allocs, (uintmax_t)sleeps,
5914 		    (unsigned)cur_zone->uz_bucket_size, (intmax_t)size,
5915 		    xdomain);
5916 
5917 		if (db_pager_quit)
5918 			return;
5919 		last_zone = cur_zone;
5920 		last_size = cur_size;
5921 	}
5922 }
5923 
5924 DB_SHOW_COMMAND_FLAGS(umacache, db_show_umacache, DB_CMD_MEMSAFE)
5925 {
5926 	uma_zone_t z;
5927 	uint64_t allocs, frees;
5928 	long cachefree;
5929 	int i;
5930 
5931 	db_printf("%18s %8s %8s %8s %12s %8s\n", "Zone", "Size", "Used", "Free",
5932 	    "Requests", "Bucket");
5933 	LIST_FOREACH(z, &uma_cachezones, uz_link) {
5934 		uma_zone_sumstat(z, &cachefree, &allocs, &frees, NULL, NULL);
5935 		for (i = 0; i < vm_ndomains; i++)
5936 			cachefree += ZDOM_GET(z, i)->uzd_nitems;
5937 		db_printf("%18s %8ju %8jd %8ld %12ju %8u\n",
5938 		    z->uz_name, (uintmax_t)z->uz_size,
5939 		    (intmax_t)(allocs - frees), cachefree,
5940 		    (uintmax_t)allocs, z->uz_bucket_size);
5941 		if (db_pager_quit)
5942 			return;
5943 	}
5944 }
5945 #endif	/* DDB */
5946