xref: /freebsd/sys/vm/uma_core.c (revision 56e766af41cd68310f5583bb893b13c006fcb44f)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2002-2019 Jeffrey Roberson <jeff@FreeBSD.org>
5  * Copyright (c) 2004, 2005 Bosko Milekic <bmilekic@FreeBSD.org>
6  * Copyright (c) 2004-2006 Robert N. M. Watson
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice unmodified, this list of conditions, and the following
14  *    disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 /*
32  * uma_core.c  Implementation of the Universal Memory allocator
33  *
34  * This allocator is intended to replace the multitude of similar object caches
35  * in the standard FreeBSD kernel.  The intent is to be flexible as well as
36  * efficient.  A primary design goal is to return unused memory to the rest of
37  * the system.  This will make the system as a whole more flexible due to the
38  * ability to move memory to subsystems which most need it instead of leaving
39  * pools of reserved memory unused.
40  *
41  * The basic ideas stem from similar slab/zone based allocators whose algorithms
42  * are well known.
43  *
44  */
45 
46 /*
47  * TODO:
48  *	- Improve memory usage for large allocations
49  *	- Investigate cache size adjustments
50  */
51 
52 #include <sys/cdefs.h>
53 __FBSDID("$FreeBSD$");
54 
55 #include "opt_ddb.h"
56 #include "opt_param.h"
57 #include "opt_vm.h"
58 
59 #include <sys/param.h>
60 #include <sys/systm.h>
61 #include <sys/bitset.h>
62 #include <sys/domainset.h>
63 #include <sys/eventhandler.h>
64 #include <sys/kernel.h>
65 #include <sys/types.h>
66 #include <sys/limits.h>
67 #include <sys/queue.h>
68 #include <sys/malloc.h>
69 #include <sys/ktr.h>
70 #include <sys/lock.h>
71 #include <sys/sysctl.h>
72 #include <sys/mutex.h>
73 #include <sys/proc.h>
74 #include <sys/random.h>
75 #include <sys/rwlock.h>
76 #include <sys/sbuf.h>
77 #include <sys/sched.h>
78 #include <sys/sleepqueue.h>
79 #include <sys/smp.h>
80 #include <sys/taskqueue.h>
81 #include <sys/vmmeter.h>
82 
83 #include <vm/vm.h>
84 #include <vm/vm_domainset.h>
85 #include <vm/vm_object.h>
86 #include <vm/vm_page.h>
87 #include <vm/vm_pageout.h>
88 #include <vm/vm_param.h>
89 #include <vm/vm_phys.h>
90 #include <vm/vm_pagequeue.h>
91 #include <vm/vm_map.h>
92 #include <vm/vm_kern.h>
93 #include <vm/vm_extern.h>
94 #include <vm/uma.h>
95 #include <vm/uma_int.h>
96 #include <vm/uma_dbg.h>
97 
98 #include <ddb/ddb.h>
99 
100 #ifdef DEBUG_MEMGUARD
101 #include <vm/memguard.h>
102 #endif
103 
104 #include <machine/md_var.h>
105 
106 /*
107  * This is the zone and keg from which all zones are spawned.
108  */
109 static uma_zone_t kegs;
110 static uma_zone_t zones;
111 
112 /*
113  * These are the two zones from which all offpage uma_slab_ts are allocated.
114  *
115  * One zone is for slab headers that can represent a larger number of items,
116  * making the slabs themselves more efficient, and the other zone is for
117  * headers that are smaller and represent fewer items, making the headers more
118  * efficient.
119  */
120 #define	SLABZONE_SIZE(setsize)					\
121     (sizeof(struct uma_hash_slab) + BITSET_SIZE(setsize) * SLAB_BITSETS)
122 #define	SLABZONE0_SETSIZE	(PAGE_SIZE / 16)
123 #define	SLABZONE1_SETSIZE	SLAB_MAX_SETSIZE
124 #define	SLABZONE0_SIZE	SLABZONE_SIZE(SLABZONE0_SETSIZE)
125 #define	SLABZONE1_SIZE	SLABZONE_SIZE(SLABZONE1_SETSIZE)
126 static uma_zone_t slabzones[2];
127 
128 /*
129  * The initial hash tables come out of this zone so they can be allocated
130  * prior to malloc coming up.
131  */
132 static uma_zone_t hashzone;
133 
134 /* The boot-time adjusted value for cache line alignment. */
135 int uma_align_cache = 64 - 1;
136 
137 static MALLOC_DEFINE(M_UMAHASH, "UMAHash", "UMA Hash Buckets");
138 static MALLOC_DEFINE(M_UMA, "UMA", "UMA Misc");
139 
140 /*
141  * Are we allowed to allocate buckets?
142  */
143 static int bucketdisable = 1;
144 
145 /* Linked list of all kegs in the system */
146 static LIST_HEAD(,uma_keg) uma_kegs = LIST_HEAD_INITIALIZER(uma_kegs);
147 
148 /* Linked list of all cache-only zones in the system */
149 static LIST_HEAD(,uma_zone) uma_cachezones =
150     LIST_HEAD_INITIALIZER(uma_cachezones);
151 
152 /* This RW lock protects the keg list */
153 static struct rwlock_padalign __exclusive_cache_line uma_rwlock;
154 
155 /*
156  * First available virual address for boot time allocations.
157  */
158 static vm_offset_t bootstart;
159 static vm_offset_t bootmem;
160 
161 static struct sx uma_reclaim_lock;
162 
163 /*
164  * kmem soft limit, initialized by uma_set_limit().  Ensure that early
165  * allocations don't trigger a wakeup of the reclaim thread.
166  */
167 unsigned long uma_kmem_limit = LONG_MAX;
168 SYSCTL_ULONG(_vm, OID_AUTO, uma_kmem_limit, CTLFLAG_RD, &uma_kmem_limit, 0,
169     "UMA kernel memory soft limit");
170 unsigned long uma_kmem_total;
171 SYSCTL_ULONG(_vm, OID_AUTO, uma_kmem_total, CTLFLAG_RD, &uma_kmem_total, 0,
172     "UMA kernel memory usage");
173 
174 /* Is the VM done starting up? */
175 static enum {
176 	BOOT_COLD,
177 	BOOT_KVA,
178 	BOOT_RUNNING,
179 	BOOT_SHUTDOWN,
180 } booted = BOOT_COLD;
181 
182 /*
183  * This is the handle used to schedule events that need to happen
184  * outside of the allocation fast path.
185  */
186 static struct callout uma_callout;
187 #define	UMA_TIMEOUT	20		/* Seconds for callout interval. */
188 
189 /*
190  * This structure is passed as the zone ctor arg so that I don't have to create
191  * a special allocation function just for zones.
192  */
193 struct uma_zctor_args {
194 	const char *name;
195 	size_t size;
196 	uma_ctor ctor;
197 	uma_dtor dtor;
198 	uma_init uminit;
199 	uma_fini fini;
200 	uma_import import;
201 	uma_release release;
202 	void *arg;
203 	uma_keg_t keg;
204 	int align;
205 	uint32_t flags;
206 };
207 
208 struct uma_kctor_args {
209 	uma_zone_t zone;
210 	size_t size;
211 	uma_init uminit;
212 	uma_fini fini;
213 	int align;
214 	uint32_t flags;
215 };
216 
217 struct uma_bucket_zone {
218 	uma_zone_t	ubz_zone;
219 	char		*ubz_name;
220 	int		ubz_entries;	/* Number of items it can hold. */
221 	int		ubz_maxsize;	/* Maximum allocation size per-item. */
222 };
223 
224 /*
225  * Compute the actual number of bucket entries to pack them in power
226  * of two sizes for more efficient space utilization.
227  */
228 #define	BUCKET_SIZE(n)						\
229     (((sizeof(void *) * (n)) - sizeof(struct uma_bucket)) / sizeof(void *))
230 
231 #define	BUCKET_MAX	BUCKET_SIZE(256)
232 #define	BUCKET_MIN	BUCKET_SIZE(4)
233 
234 struct uma_bucket_zone bucket_zones[] = {
235 	{ NULL, "4 Bucket", BUCKET_SIZE(4), 4096 },
236 	{ NULL, "6 Bucket", BUCKET_SIZE(6), 3072 },
237 	{ NULL, "8 Bucket", BUCKET_SIZE(8), 2048 },
238 	{ NULL, "12 Bucket", BUCKET_SIZE(12), 1536 },
239 	{ NULL, "16 Bucket", BUCKET_SIZE(16), 1024 },
240 	{ NULL, "32 Bucket", BUCKET_SIZE(32), 512 },
241 	{ NULL, "64 Bucket", BUCKET_SIZE(64), 256 },
242 	{ NULL, "128 Bucket", BUCKET_SIZE(128), 128 },
243 	{ NULL, "256 Bucket", BUCKET_SIZE(256), 64 },
244 	{ NULL, NULL, 0}
245 };
246 
247 /*
248  * Flags and enumerations to be passed to internal functions.
249  */
250 enum zfreeskip {
251 	SKIP_NONE =	0,
252 	SKIP_CNT =	0x00000001,
253 	SKIP_DTOR =	0x00010000,
254 	SKIP_FINI =	0x00020000,
255 };
256 
257 /* Prototypes.. */
258 
259 void	uma_startup1(vm_offset_t);
260 void	uma_startup2(void);
261 
262 static void *noobj_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
263 static void *page_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
264 static void *pcpu_page_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
265 static void *startup_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
266 static void page_free(void *, vm_size_t, uint8_t);
267 static void pcpu_page_free(void *, vm_size_t, uint8_t);
268 static uma_slab_t keg_alloc_slab(uma_keg_t, uma_zone_t, int, int, int);
269 static void cache_drain(uma_zone_t);
270 static void bucket_drain(uma_zone_t, uma_bucket_t);
271 static void bucket_cache_reclaim(uma_zone_t zone, bool);
272 static int keg_ctor(void *, int, void *, int);
273 static void keg_dtor(void *, int, void *);
274 static int zone_ctor(void *, int, void *, int);
275 static void zone_dtor(void *, int, void *);
276 static int zero_init(void *, int, int);
277 static void zone_foreach(void (*zfunc)(uma_zone_t, void *), void *);
278 static void zone_foreach_unlocked(void (*zfunc)(uma_zone_t, void *), void *);
279 static void zone_timeout(uma_zone_t zone, void *);
280 static int hash_alloc(struct uma_hash *, u_int);
281 static int hash_expand(struct uma_hash *, struct uma_hash *);
282 static void hash_free(struct uma_hash *hash);
283 static void uma_timeout(void *);
284 static void uma_startup3(void);
285 static void uma_shutdown(void);
286 static void *zone_alloc_item(uma_zone_t, void *, int, int);
287 static void zone_free_item(uma_zone_t, void *, void *, enum zfreeskip);
288 static int zone_alloc_limit(uma_zone_t zone, int count, int flags);
289 static void zone_free_limit(uma_zone_t zone, int count);
290 static void bucket_enable(void);
291 static void bucket_init(void);
292 static uma_bucket_t bucket_alloc(uma_zone_t zone, void *, int);
293 static void bucket_free(uma_zone_t zone, uma_bucket_t, void *);
294 static void bucket_zone_drain(void);
295 static uma_bucket_t zone_alloc_bucket(uma_zone_t, void *, int, int);
296 static void *slab_alloc_item(uma_keg_t keg, uma_slab_t slab);
297 static void slab_free_item(uma_zone_t zone, uma_slab_t slab, void *item);
298 static uma_keg_t uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit,
299     uma_fini fini, int align, uint32_t flags);
300 static int zone_import(void *, void **, int, int, int);
301 static void zone_release(void *, void **, int);
302 static bool cache_alloc(uma_zone_t, uma_cache_t, void *, int);
303 static bool cache_free(uma_zone_t, uma_cache_t, void *, void *, int);
304 
305 static int sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS);
306 static int sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS);
307 static int sysctl_handle_uma_zone_allocs(SYSCTL_HANDLER_ARGS);
308 static int sysctl_handle_uma_zone_frees(SYSCTL_HANDLER_ARGS);
309 static int sysctl_handle_uma_zone_flags(SYSCTL_HANDLER_ARGS);
310 static int sysctl_handle_uma_slab_efficiency(SYSCTL_HANDLER_ARGS);
311 static int sysctl_handle_uma_zone_items(SYSCTL_HANDLER_ARGS);
312 
313 static uint64_t uma_zone_get_allocs(uma_zone_t zone);
314 
315 #ifdef INVARIANTS
316 static uint64_t uma_keg_get_allocs(uma_keg_t zone);
317 static inline struct noslabbits *slab_dbg_bits(uma_slab_t slab, uma_keg_t keg);
318 
319 static bool uma_dbg_kskip(uma_keg_t keg, void *mem);
320 static bool uma_dbg_zskip(uma_zone_t zone, void *mem);
321 static void uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item);
322 static void uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item);
323 
324 static SYSCTL_NODE(_vm, OID_AUTO, debug, CTLFLAG_RD, 0,
325     "Memory allocation debugging");
326 
327 static u_int dbg_divisor = 1;
328 SYSCTL_UINT(_vm_debug, OID_AUTO, divisor,
329     CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &dbg_divisor, 0,
330     "Debug & thrash every this item in memory allocator");
331 
332 static counter_u64_t uma_dbg_cnt = EARLY_COUNTER;
333 static counter_u64_t uma_skip_cnt = EARLY_COUNTER;
334 SYSCTL_COUNTER_U64(_vm_debug, OID_AUTO, trashed, CTLFLAG_RD,
335     &uma_dbg_cnt, "memory items debugged");
336 SYSCTL_COUNTER_U64(_vm_debug, OID_AUTO, skipped, CTLFLAG_RD,
337     &uma_skip_cnt, "memory items skipped, not debugged");
338 #endif
339 
340 SYSINIT(uma_startup3, SI_SUB_VM_CONF, SI_ORDER_SECOND, uma_startup3, NULL);
341 
342 SYSCTL_NODE(_vm, OID_AUTO, uma, CTLFLAG_RW, 0, "Universal Memory Allocator");
343 
344 SYSCTL_PROC(_vm, OID_AUTO, zone_count, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLTYPE_INT,
345     0, 0, sysctl_vm_zone_count, "I", "Number of UMA zones");
346 
347 SYSCTL_PROC(_vm, OID_AUTO, zone_stats, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLTYPE_STRUCT,
348     0, 0, sysctl_vm_zone_stats, "s,struct uma_type_header", "Zone Stats");
349 
350 static int zone_warnings = 1;
351 SYSCTL_INT(_vm, OID_AUTO, zone_warnings, CTLFLAG_RWTUN, &zone_warnings, 0,
352     "Warn when UMA zones becomes full");
353 
354 /*
355  * Select the slab zone for an offpage slab with the given maximum item count.
356  */
357 static inline uma_zone_t
358 slabzone(int ipers)
359 {
360 
361 	return (slabzones[ipers > SLABZONE0_SETSIZE]);
362 }
363 
364 /*
365  * This routine checks to see whether or not it's safe to enable buckets.
366  */
367 static void
368 bucket_enable(void)
369 {
370 
371 	KASSERT(booted >= BOOT_KVA, ("Bucket enable before init"));
372 	bucketdisable = vm_page_count_min();
373 }
374 
375 /*
376  * Initialize bucket_zones, the array of zones of buckets of various sizes.
377  *
378  * For each zone, calculate the memory required for each bucket, consisting
379  * of the header and an array of pointers.
380  */
381 static void
382 bucket_init(void)
383 {
384 	struct uma_bucket_zone *ubz;
385 	int size;
386 
387 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++) {
388 		size = roundup(sizeof(struct uma_bucket), sizeof(void *));
389 		size += sizeof(void *) * ubz->ubz_entries;
390 		ubz->ubz_zone = uma_zcreate(ubz->ubz_name, size,
391 		    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR,
392 		    UMA_ZONE_MTXCLASS | UMA_ZFLAG_BUCKET |
393 		    UMA_ZONE_FIRSTTOUCH);
394 	}
395 }
396 
397 /*
398  * Given a desired number of entries for a bucket, return the zone from which
399  * to allocate the bucket.
400  */
401 static struct uma_bucket_zone *
402 bucket_zone_lookup(int entries)
403 {
404 	struct uma_bucket_zone *ubz;
405 
406 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
407 		if (ubz->ubz_entries >= entries)
408 			return (ubz);
409 	ubz--;
410 	return (ubz);
411 }
412 
413 static struct uma_bucket_zone *
414 bucket_zone_max(uma_zone_t zone, int nitems)
415 {
416 	struct uma_bucket_zone *ubz;
417 	int bpcpu;
418 
419 	bpcpu = 2;
420 	if ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) != 0)
421 		/* Count the cross-domain bucket. */
422 		bpcpu++;
423 
424 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
425 		if (ubz->ubz_entries * bpcpu * mp_ncpus > nitems)
426 			break;
427 	if (ubz == &bucket_zones[0])
428 		ubz = NULL;
429 	else
430 		ubz--;
431 	return (ubz);
432 }
433 
434 static int
435 bucket_select(int size)
436 {
437 	struct uma_bucket_zone *ubz;
438 
439 	ubz = &bucket_zones[0];
440 	if (size > ubz->ubz_maxsize)
441 		return MAX((ubz->ubz_maxsize * ubz->ubz_entries) / size, 1);
442 
443 	for (; ubz->ubz_entries != 0; ubz++)
444 		if (ubz->ubz_maxsize < size)
445 			break;
446 	ubz--;
447 	return (ubz->ubz_entries);
448 }
449 
450 static uma_bucket_t
451 bucket_alloc(uma_zone_t zone, void *udata, int flags)
452 {
453 	struct uma_bucket_zone *ubz;
454 	uma_bucket_t bucket;
455 
456 	/*
457 	 * Don't allocate buckets in low memory situations.
458 	 */
459 	if (bucketdisable)
460 		return (NULL);
461 
462 	/*
463 	 * To limit bucket recursion we store the original zone flags
464 	 * in a cookie passed via zalloc_arg/zfree_arg.  This allows the
465 	 * NOVM flag to persist even through deep recursions.  We also
466 	 * store ZFLAG_BUCKET once we have recursed attempting to allocate
467 	 * a bucket for a bucket zone so we do not allow infinite bucket
468 	 * recursion.  This cookie will even persist to frees of unused
469 	 * buckets via the allocation path or bucket allocations in the
470 	 * free path.
471 	 */
472 	if ((zone->uz_flags & UMA_ZFLAG_BUCKET) == 0)
473 		udata = (void *)(uintptr_t)zone->uz_flags;
474 	else {
475 		if ((uintptr_t)udata & UMA_ZFLAG_BUCKET)
476 			return (NULL);
477 		udata = (void *)((uintptr_t)udata | UMA_ZFLAG_BUCKET);
478 	}
479 	if ((uintptr_t)udata & UMA_ZFLAG_CACHEONLY)
480 		flags |= M_NOVM;
481 	ubz = bucket_zone_lookup(zone->uz_bucket_size);
482 	if (ubz->ubz_zone == zone && (ubz + 1)->ubz_entries != 0)
483 		ubz++;
484 	bucket = uma_zalloc_arg(ubz->ubz_zone, udata, flags);
485 	if (bucket) {
486 #ifdef INVARIANTS
487 		bzero(bucket->ub_bucket, sizeof(void *) * ubz->ubz_entries);
488 #endif
489 		bucket->ub_cnt = 0;
490 		bucket->ub_entries = ubz->ubz_entries;
491 	}
492 
493 	return (bucket);
494 }
495 
496 static void
497 bucket_free(uma_zone_t zone, uma_bucket_t bucket, void *udata)
498 {
499 	struct uma_bucket_zone *ubz;
500 
501 	KASSERT(bucket->ub_cnt == 0,
502 	    ("bucket_free: Freeing a non free bucket."));
503 	if ((zone->uz_flags & UMA_ZFLAG_BUCKET) == 0)
504 		udata = (void *)(uintptr_t)zone->uz_flags;
505 	ubz = bucket_zone_lookup(bucket->ub_entries);
506 	uma_zfree_arg(ubz->ubz_zone, bucket, udata);
507 }
508 
509 static void
510 bucket_zone_drain(void)
511 {
512 	struct uma_bucket_zone *ubz;
513 
514 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
515 		uma_zone_reclaim(ubz->ubz_zone, UMA_RECLAIM_DRAIN);
516 }
517 
518 /*
519  * Attempt to satisfy an allocation by retrieving a full bucket from one of the
520  * zone's caches.
521  */
522 static uma_bucket_t
523 zone_fetch_bucket(uma_zone_t zone, uma_zone_domain_t zdom)
524 {
525 	uma_bucket_t bucket;
526 
527 	ZONE_LOCK_ASSERT(zone);
528 
529 	if ((bucket = TAILQ_FIRST(&zdom->uzd_buckets)) != NULL) {
530 		MPASS(zdom->uzd_nitems >= bucket->ub_cnt);
531 		TAILQ_REMOVE(&zdom->uzd_buckets, bucket, ub_link);
532 		zdom->uzd_nitems -= bucket->ub_cnt;
533 		if (zdom->uzd_imin > zdom->uzd_nitems)
534 			zdom->uzd_imin = zdom->uzd_nitems;
535 		zone->uz_bkt_count -= bucket->ub_cnt;
536 	}
537 	return (bucket);
538 }
539 
540 /*
541  * Insert a full bucket into the specified cache.  The "ws" parameter indicates
542  * whether the bucket's contents should be counted as part of the zone's working
543  * set.
544  */
545 static void
546 zone_put_bucket(uma_zone_t zone, uma_zone_domain_t zdom, uma_bucket_t bucket,
547     const bool ws)
548 {
549 
550 	ZONE_LOCK_ASSERT(zone);
551 	KASSERT(!ws || zone->uz_bkt_count < zone->uz_bkt_max,
552 	    ("%s: zone %p overflow", __func__, zone));
553 
554 	if (ws)
555 		TAILQ_INSERT_HEAD(&zdom->uzd_buckets, bucket, ub_link);
556 	else
557 		TAILQ_INSERT_TAIL(&zdom->uzd_buckets, bucket, ub_link);
558 	zdom->uzd_nitems += bucket->ub_cnt;
559 	if (ws && zdom->uzd_imax < zdom->uzd_nitems)
560 		zdom->uzd_imax = zdom->uzd_nitems;
561 	zone->uz_bkt_count += bucket->ub_cnt;
562 }
563 
564 /* Pops an item out of a per-cpu cache bucket. */
565 static inline void *
566 cache_bucket_pop(uma_cache_t cache, uma_cache_bucket_t bucket)
567 {
568 	void *item;
569 
570 	CRITICAL_ASSERT(curthread);
571 
572 	bucket->ucb_cnt--;
573 	item = bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt];
574 #ifdef INVARIANTS
575 	bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt] = NULL;
576 	KASSERT(item != NULL, ("uma_zalloc: Bucket pointer mangled."));
577 #endif
578 	cache->uc_allocs++;
579 
580 	return (item);
581 }
582 
583 /* Pushes an item into a per-cpu cache bucket. */
584 static inline void
585 cache_bucket_push(uma_cache_t cache, uma_cache_bucket_t bucket, void *item)
586 {
587 
588 	CRITICAL_ASSERT(curthread);
589 	KASSERT(bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt] == NULL,
590 	    ("uma_zfree: Freeing to non free bucket index."));
591 
592 	bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt] = item;
593 	bucket->ucb_cnt++;
594 	cache->uc_frees++;
595 }
596 
597 /*
598  * Unload a UMA bucket from a per-cpu cache.
599  */
600 static inline uma_bucket_t
601 cache_bucket_unload(uma_cache_bucket_t bucket)
602 {
603 	uma_bucket_t b;
604 
605 	b = bucket->ucb_bucket;
606 	if (b != NULL) {
607 		MPASS(b->ub_entries == bucket->ucb_entries);
608 		b->ub_cnt = bucket->ucb_cnt;
609 		bucket->ucb_bucket = NULL;
610 		bucket->ucb_entries = bucket->ucb_cnt = 0;
611 	}
612 
613 	return (b);
614 }
615 
616 static inline uma_bucket_t
617 cache_bucket_unload_alloc(uma_cache_t cache)
618 {
619 
620 	return (cache_bucket_unload(&cache->uc_allocbucket));
621 }
622 
623 static inline uma_bucket_t
624 cache_bucket_unload_free(uma_cache_t cache)
625 {
626 
627 	return (cache_bucket_unload(&cache->uc_freebucket));
628 }
629 
630 static inline uma_bucket_t
631 cache_bucket_unload_cross(uma_cache_t cache)
632 {
633 
634 	return (cache_bucket_unload(&cache->uc_crossbucket));
635 }
636 
637 /*
638  * Load a bucket into a per-cpu cache bucket.
639  */
640 static inline void
641 cache_bucket_load(uma_cache_bucket_t bucket, uma_bucket_t b)
642 {
643 
644 	CRITICAL_ASSERT(curthread);
645 	MPASS(bucket->ucb_bucket == NULL);
646 
647 	bucket->ucb_bucket = b;
648 	bucket->ucb_cnt = b->ub_cnt;
649 	bucket->ucb_entries = b->ub_entries;
650 }
651 
652 static inline void
653 cache_bucket_load_alloc(uma_cache_t cache, uma_bucket_t b)
654 {
655 
656 	cache_bucket_load(&cache->uc_allocbucket, b);
657 }
658 
659 static inline void
660 cache_bucket_load_free(uma_cache_t cache, uma_bucket_t b)
661 {
662 
663 	cache_bucket_load(&cache->uc_freebucket, b);
664 }
665 
666 #ifdef NUMA
667 static inline void
668 cache_bucket_load_cross(uma_cache_t cache, uma_bucket_t b)
669 {
670 
671 	cache_bucket_load(&cache->uc_crossbucket, b);
672 }
673 #endif
674 
675 /*
676  * Copy and preserve ucb_spare.
677  */
678 static inline void
679 cache_bucket_copy(uma_cache_bucket_t b1, uma_cache_bucket_t b2)
680 {
681 
682 	b1->ucb_bucket = b2->ucb_bucket;
683 	b1->ucb_entries = b2->ucb_entries;
684 	b1->ucb_cnt = b2->ucb_cnt;
685 }
686 
687 /*
688  * Swap two cache buckets.
689  */
690 static inline void
691 cache_bucket_swap(uma_cache_bucket_t b1, uma_cache_bucket_t b2)
692 {
693 	struct uma_cache_bucket b3;
694 
695 	CRITICAL_ASSERT(curthread);
696 
697 	cache_bucket_copy(&b3, b1);
698 	cache_bucket_copy(b1, b2);
699 	cache_bucket_copy(b2, &b3);
700 }
701 
702 static void
703 zone_log_warning(uma_zone_t zone)
704 {
705 	static const struct timeval warninterval = { 300, 0 };
706 
707 	if (!zone_warnings || zone->uz_warning == NULL)
708 		return;
709 
710 	if (ratecheck(&zone->uz_ratecheck, &warninterval))
711 		printf("[zone: %s] %s\n", zone->uz_name, zone->uz_warning);
712 }
713 
714 static inline void
715 zone_maxaction(uma_zone_t zone)
716 {
717 
718 	if (zone->uz_maxaction.ta_func != NULL)
719 		taskqueue_enqueue(taskqueue_thread, &zone->uz_maxaction);
720 }
721 
722 /*
723  * Routine called by timeout which is used to fire off some time interval
724  * based calculations.  (stats, hash size, etc.)
725  *
726  * Arguments:
727  *	arg   Unused
728  *
729  * Returns:
730  *	Nothing
731  */
732 static void
733 uma_timeout(void *unused)
734 {
735 	bucket_enable();
736 	zone_foreach(zone_timeout, NULL);
737 
738 	/* Reschedule this event */
739 	callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
740 }
741 
742 /*
743  * Update the working set size estimate for the zone's bucket cache.
744  * The constants chosen here are somewhat arbitrary.  With an update period of
745  * 20s (UMA_TIMEOUT), this estimate is dominated by zone activity over the
746  * last 100s.
747  */
748 static void
749 zone_domain_update_wss(uma_zone_domain_t zdom)
750 {
751 	long wss;
752 
753 	MPASS(zdom->uzd_imax >= zdom->uzd_imin);
754 	wss = zdom->uzd_imax - zdom->uzd_imin;
755 	zdom->uzd_imax = zdom->uzd_imin = zdom->uzd_nitems;
756 	zdom->uzd_wss = (4 * wss + zdom->uzd_wss) / 5;
757 }
758 
759 /*
760  * Routine to perform timeout driven calculations.  This expands the
761  * hashes and does per cpu statistics aggregation.
762  *
763  *  Returns nothing.
764  */
765 static void
766 zone_timeout(uma_zone_t zone, void *unused)
767 {
768 	uma_keg_t keg;
769 	u_int slabs, pages;
770 
771 	if ((zone->uz_flags & UMA_ZFLAG_HASH) == 0)
772 		goto update_wss;
773 
774 	keg = zone->uz_keg;
775 
776 	/*
777 	 * Hash zones are non-numa by definition so the first domain
778 	 * is the only one present.
779 	 */
780 	KEG_LOCK(keg, 0);
781 	pages = keg->uk_domain[0].ud_pages;
782 
783 	/*
784 	 * Expand the keg hash table.
785 	 *
786 	 * This is done if the number of slabs is larger than the hash size.
787 	 * What I'm trying to do here is completely reduce collisions.  This
788 	 * may be a little aggressive.  Should I allow for two collisions max?
789 	 */
790 	if ((slabs = pages / keg->uk_ppera) > keg->uk_hash.uh_hashsize) {
791 		struct uma_hash newhash;
792 		struct uma_hash oldhash;
793 		int ret;
794 
795 		/*
796 		 * This is so involved because allocating and freeing
797 		 * while the keg lock is held will lead to deadlock.
798 		 * I have to do everything in stages and check for
799 		 * races.
800 		 */
801 		KEG_UNLOCK(keg, 0);
802 		ret = hash_alloc(&newhash, 1 << fls(slabs));
803 		KEG_LOCK(keg, 0);
804 		if (ret) {
805 			if (hash_expand(&keg->uk_hash, &newhash)) {
806 				oldhash = keg->uk_hash;
807 				keg->uk_hash = newhash;
808 			} else
809 				oldhash = newhash;
810 
811 			KEG_UNLOCK(keg, 0);
812 			hash_free(&oldhash);
813 			goto update_wss;
814 		}
815 	}
816 	KEG_UNLOCK(keg, 0);
817 
818 update_wss:
819 	ZONE_LOCK(zone);
820 	for (int i = 0; i < vm_ndomains; i++)
821 		zone_domain_update_wss(&zone->uz_domain[i]);
822 	ZONE_UNLOCK(zone);
823 }
824 
825 /*
826  * Allocate and zero fill the next sized hash table from the appropriate
827  * backing store.
828  *
829  * Arguments:
830  *	hash  A new hash structure with the old hash size in uh_hashsize
831  *
832  * Returns:
833  *	1 on success and 0 on failure.
834  */
835 static int
836 hash_alloc(struct uma_hash *hash, u_int size)
837 {
838 	size_t alloc;
839 
840 	KASSERT(powerof2(size), ("hash size must be power of 2"));
841 	if (size > UMA_HASH_SIZE_INIT)  {
842 		hash->uh_hashsize = size;
843 		alloc = sizeof(hash->uh_slab_hash[0]) * hash->uh_hashsize;
844 		hash->uh_slab_hash = malloc(alloc, M_UMAHASH, M_NOWAIT);
845 	} else {
846 		alloc = sizeof(hash->uh_slab_hash[0]) * UMA_HASH_SIZE_INIT;
847 		hash->uh_slab_hash = zone_alloc_item(hashzone, NULL,
848 		    UMA_ANYDOMAIN, M_WAITOK);
849 		hash->uh_hashsize = UMA_HASH_SIZE_INIT;
850 	}
851 	if (hash->uh_slab_hash) {
852 		bzero(hash->uh_slab_hash, alloc);
853 		hash->uh_hashmask = hash->uh_hashsize - 1;
854 		return (1);
855 	}
856 
857 	return (0);
858 }
859 
860 /*
861  * Expands the hash table for HASH zones.  This is done from zone_timeout
862  * to reduce collisions.  This must not be done in the regular allocation
863  * path, otherwise, we can recurse on the vm while allocating pages.
864  *
865  * Arguments:
866  *	oldhash  The hash you want to expand
867  *	newhash  The hash structure for the new table
868  *
869  * Returns:
870  *	Nothing
871  *
872  * Discussion:
873  */
874 static int
875 hash_expand(struct uma_hash *oldhash, struct uma_hash *newhash)
876 {
877 	uma_hash_slab_t slab;
878 	u_int hval;
879 	u_int idx;
880 
881 	if (!newhash->uh_slab_hash)
882 		return (0);
883 
884 	if (oldhash->uh_hashsize >= newhash->uh_hashsize)
885 		return (0);
886 
887 	/*
888 	 * I need to investigate hash algorithms for resizing without a
889 	 * full rehash.
890 	 */
891 
892 	for (idx = 0; idx < oldhash->uh_hashsize; idx++)
893 		while (!LIST_EMPTY(&oldhash->uh_slab_hash[idx])) {
894 			slab = LIST_FIRST(&oldhash->uh_slab_hash[idx]);
895 			LIST_REMOVE(slab, uhs_hlink);
896 			hval = UMA_HASH(newhash, slab->uhs_data);
897 			LIST_INSERT_HEAD(&newhash->uh_slab_hash[hval],
898 			    slab, uhs_hlink);
899 		}
900 
901 	return (1);
902 }
903 
904 /*
905  * Free the hash bucket to the appropriate backing store.
906  *
907  * Arguments:
908  *	slab_hash  The hash bucket we're freeing
909  *	hashsize   The number of entries in that hash bucket
910  *
911  * Returns:
912  *	Nothing
913  */
914 static void
915 hash_free(struct uma_hash *hash)
916 {
917 	if (hash->uh_slab_hash == NULL)
918 		return;
919 	if (hash->uh_hashsize == UMA_HASH_SIZE_INIT)
920 		zone_free_item(hashzone, hash->uh_slab_hash, NULL, SKIP_NONE);
921 	else
922 		free(hash->uh_slab_hash, M_UMAHASH);
923 }
924 
925 /*
926  * Frees all outstanding items in a bucket
927  *
928  * Arguments:
929  *	zone   The zone to free to, must be unlocked.
930  *	bucket The free/alloc bucket with items.
931  *
932  * Returns:
933  *	Nothing
934  */
935 
936 static void
937 bucket_drain(uma_zone_t zone, uma_bucket_t bucket)
938 {
939 	int i;
940 
941 	if (bucket == NULL || bucket->ub_cnt == 0)
942 		return;
943 
944 	if (zone->uz_fini)
945 		for (i = 0; i < bucket->ub_cnt; i++)
946 			zone->uz_fini(bucket->ub_bucket[i], zone->uz_size);
947 	zone->uz_release(zone->uz_arg, bucket->ub_bucket, bucket->ub_cnt);
948 	if (zone->uz_max_items > 0)
949 		zone_free_limit(zone, bucket->ub_cnt);
950 	bucket->ub_cnt = 0;
951 }
952 
953 /*
954  * Drains the per cpu caches for a zone.
955  *
956  * NOTE: This may only be called while the zone is being torn down, and not
957  * during normal operation.  This is necessary in order that we do not have
958  * to migrate CPUs to drain the per-CPU caches.
959  *
960  * Arguments:
961  *	zone     The zone to drain, must be unlocked.
962  *
963  * Returns:
964  *	Nothing
965  */
966 static void
967 cache_drain(uma_zone_t zone)
968 {
969 	uma_cache_t cache;
970 	uma_bucket_t bucket;
971 	int cpu;
972 
973 	/*
974 	 * XXX: It is safe to not lock the per-CPU caches, because we're
975 	 * tearing down the zone anyway.  I.e., there will be no further use
976 	 * of the caches at this point.
977 	 *
978 	 * XXX: It would good to be able to assert that the zone is being
979 	 * torn down to prevent improper use of cache_drain().
980 	 */
981 	CPU_FOREACH(cpu) {
982 		cache = &zone->uz_cpu[cpu];
983 		bucket = cache_bucket_unload_alloc(cache);
984 		if (bucket != NULL) {
985 			bucket_drain(zone, bucket);
986 			bucket_free(zone, bucket, NULL);
987 		}
988 		bucket = cache_bucket_unload_free(cache);
989 		if (bucket != NULL) {
990 			bucket_drain(zone, bucket);
991 			bucket_free(zone, bucket, NULL);
992 		}
993 		bucket = cache_bucket_unload_cross(cache);
994 		if (bucket != NULL) {
995 			bucket_drain(zone, bucket);
996 			bucket_free(zone, bucket, NULL);
997 		}
998 	}
999 	bucket_cache_reclaim(zone, true);
1000 }
1001 
1002 static void
1003 cache_shrink(uma_zone_t zone, void *unused)
1004 {
1005 
1006 	if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
1007 		return;
1008 
1009 	ZONE_LOCK(zone);
1010 	zone->uz_bucket_size =
1011 	    (zone->uz_bucket_size_min + zone->uz_bucket_size) / 2;
1012 	ZONE_UNLOCK(zone);
1013 }
1014 
1015 static void
1016 cache_drain_safe_cpu(uma_zone_t zone, void *unused)
1017 {
1018 	uma_cache_t cache;
1019 	uma_bucket_t b1, b2, b3;
1020 	int domain;
1021 
1022 	if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
1023 		return;
1024 
1025 	b1 = b2 = b3 = NULL;
1026 	ZONE_LOCK(zone);
1027 	critical_enter();
1028 	if (zone->uz_flags & UMA_ZONE_FIRSTTOUCH)
1029 		domain = PCPU_GET(domain);
1030 	else
1031 		domain = 0;
1032 	cache = &zone->uz_cpu[curcpu];
1033 	b1 = cache_bucket_unload_alloc(cache);
1034 	if (b1 != NULL && b1->ub_cnt != 0) {
1035 		zone_put_bucket(zone, &zone->uz_domain[domain], b1, false);
1036 		b1 = NULL;
1037 	}
1038 	b2 = cache_bucket_unload_free(cache);
1039 	if (b2 != NULL && b2->ub_cnt != 0) {
1040 		zone_put_bucket(zone, &zone->uz_domain[domain], b2, false);
1041 		b2 = NULL;
1042 	}
1043 	b3 = cache_bucket_unload_cross(cache);
1044 	critical_exit();
1045 	ZONE_UNLOCK(zone);
1046 	if (b1)
1047 		bucket_free(zone, b1, NULL);
1048 	if (b2)
1049 		bucket_free(zone, b2, NULL);
1050 	if (b3) {
1051 		bucket_drain(zone, b3);
1052 		bucket_free(zone, b3, NULL);
1053 	}
1054 }
1055 
1056 /*
1057  * Safely drain per-CPU caches of a zone(s) to alloc bucket.
1058  * This is an expensive call because it needs to bind to all CPUs
1059  * one by one and enter a critical section on each of them in order
1060  * to safely access their cache buckets.
1061  * Zone lock must not be held on call this function.
1062  */
1063 static void
1064 pcpu_cache_drain_safe(uma_zone_t zone)
1065 {
1066 	int cpu;
1067 
1068 	/*
1069 	 * Polite bucket sizes shrinking was not enough, shrink aggressively.
1070 	 */
1071 	if (zone)
1072 		cache_shrink(zone, NULL);
1073 	else
1074 		zone_foreach(cache_shrink, NULL);
1075 
1076 	CPU_FOREACH(cpu) {
1077 		thread_lock(curthread);
1078 		sched_bind(curthread, cpu);
1079 		thread_unlock(curthread);
1080 
1081 		if (zone)
1082 			cache_drain_safe_cpu(zone, NULL);
1083 		else
1084 			zone_foreach(cache_drain_safe_cpu, NULL);
1085 	}
1086 	thread_lock(curthread);
1087 	sched_unbind(curthread);
1088 	thread_unlock(curthread);
1089 }
1090 
1091 /*
1092  * Reclaim cached buckets from a zone.  All buckets are reclaimed if the caller
1093  * requested a drain, otherwise the per-domain caches are trimmed to either
1094  * estimated working set size.
1095  */
1096 static void
1097 bucket_cache_reclaim(uma_zone_t zone, bool drain)
1098 {
1099 	uma_zone_domain_t zdom;
1100 	uma_bucket_t bucket;
1101 	long target, tofree;
1102 	int i;
1103 
1104 	for (i = 0; i < vm_ndomains; i++) {
1105 		/*
1106 		 * The cross bucket is partially filled and not part of
1107 		 * the item count.  Reclaim it individually here.
1108 		 */
1109 		zdom = &zone->uz_domain[i];
1110 		ZONE_CROSS_LOCK(zone);
1111 		bucket = zdom->uzd_cross;
1112 		zdom->uzd_cross = NULL;
1113 		ZONE_CROSS_UNLOCK(zone);
1114 		if (bucket != NULL) {
1115 			bucket_drain(zone, bucket);
1116 			bucket_free(zone, bucket, NULL);
1117 		}
1118 
1119 		/*
1120 		 * Shrink the zone bucket size to ensure that the per-CPU caches
1121 		 * don't grow too large.
1122 		 */
1123 		ZONE_LOCK(zone);
1124 		if (i == 0 && zone->uz_bucket_size > zone->uz_bucket_size_min)
1125 			zone->uz_bucket_size--;
1126 
1127 		/*
1128 		 * If we were asked to drain the zone, we are done only once
1129 		 * this bucket cache is empty.  Otherwise, we reclaim items in
1130 		 * excess of the zone's estimated working set size.  If the
1131 		 * difference nitems - imin is larger than the WSS estimate,
1132 		 * then the estimate will grow at the end of this interval and
1133 		 * we ignore the historical average.
1134 		 */
1135 		target = drain ? 0 : lmax(zdom->uzd_wss, zdom->uzd_nitems -
1136 		    zdom->uzd_imin);
1137 		while (zdom->uzd_nitems > target) {
1138 			bucket = TAILQ_LAST(&zdom->uzd_buckets, uma_bucketlist);
1139 			if (bucket == NULL)
1140 				break;
1141 			tofree = bucket->ub_cnt;
1142 			TAILQ_REMOVE(&zdom->uzd_buckets, bucket, ub_link);
1143 			zdom->uzd_nitems -= tofree;
1144 
1145 			/*
1146 			 * Shift the bounds of the current WSS interval to avoid
1147 			 * perturbing the estimate.
1148 			 */
1149 			zdom->uzd_imax -= lmin(zdom->uzd_imax, tofree);
1150 			zdom->uzd_imin -= lmin(zdom->uzd_imin, tofree);
1151 
1152 			ZONE_UNLOCK(zone);
1153 			bucket_drain(zone, bucket);
1154 			bucket_free(zone, bucket, NULL);
1155 			ZONE_LOCK(zone);
1156 		}
1157 		ZONE_UNLOCK(zone);
1158 	}
1159 }
1160 
1161 static void
1162 keg_free_slab(uma_keg_t keg, uma_slab_t slab, int start)
1163 {
1164 	uint8_t *mem;
1165 	int i;
1166 	uint8_t flags;
1167 
1168 	CTR4(KTR_UMA, "keg_free_slab keg %s(%p) slab %p, returning %d bytes",
1169 	    keg->uk_name, keg, slab, PAGE_SIZE * keg->uk_ppera);
1170 
1171 	mem = slab_data(slab, keg);
1172 	flags = slab->us_flags;
1173 	i = start;
1174 	if (keg->uk_fini != NULL) {
1175 		for (i--; i > -1; i--)
1176 #ifdef INVARIANTS
1177 		/*
1178 		 * trash_fini implies that dtor was trash_dtor. trash_fini
1179 		 * would check that memory hasn't been modified since free,
1180 		 * which executed trash_dtor.
1181 		 * That's why we need to run uma_dbg_kskip() check here,
1182 		 * albeit we don't make skip check for other init/fini
1183 		 * invocations.
1184 		 */
1185 		if (!uma_dbg_kskip(keg, slab_item(slab, keg, i)) ||
1186 		    keg->uk_fini != trash_fini)
1187 #endif
1188 			keg->uk_fini(slab_item(slab, keg, i), keg->uk_size);
1189 	}
1190 	if (keg->uk_flags & UMA_ZFLAG_OFFPAGE)
1191 		zone_free_item(slabzone(keg->uk_ipers), slab_tohashslab(slab),
1192 		    NULL, SKIP_NONE);
1193 	keg->uk_freef(mem, PAGE_SIZE * keg->uk_ppera, flags);
1194 	uma_total_dec(PAGE_SIZE * keg->uk_ppera);
1195 }
1196 
1197 /*
1198  * Frees pages from a keg back to the system.  This is done on demand from
1199  * the pageout daemon.
1200  *
1201  * Returns nothing.
1202  */
1203 static void
1204 keg_drain(uma_keg_t keg)
1205 {
1206 	struct slabhead freeslabs = { 0 };
1207 	uma_domain_t dom;
1208 	uma_slab_t slab, tmp;
1209 	int i, n;
1210 
1211 	/*
1212 	 * We don't want to take pages from statically allocated kegs at this
1213 	 * time
1214 	 */
1215 	if (keg->uk_flags & UMA_ZONE_NOFREE || keg->uk_freef == NULL)
1216 		return;
1217 
1218 	for (i = 0; i < vm_ndomains; i++) {
1219 		CTR4(KTR_UMA, "keg_drain %s(%p) domain %d free items: %u",
1220 		    keg->uk_name, keg, i, dom->ud_free);
1221 		n = 0;
1222 		dom = &keg->uk_domain[i];
1223 		KEG_LOCK(keg, i);
1224 		LIST_FOREACH_SAFE(slab, &dom->ud_free_slab, us_link, tmp) {
1225 			if (keg->uk_flags & UMA_ZFLAG_HASH)
1226 				UMA_HASH_REMOVE(&keg->uk_hash, slab);
1227 			n++;
1228 			LIST_REMOVE(slab, us_link);
1229 			LIST_INSERT_HEAD(&freeslabs, slab, us_link);
1230 		}
1231 		dom->ud_pages -= n * keg->uk_ppera;
1232 		dom->ud_free -= n * keg->uk_ipers;
1233 		KEG_UNLOCK(keg, i);
1234 	}
1235 
1236 	while ((slab = LIST_FIRST(&freeslabs)) != NULL) {
1237 		LIST_REMOVE(slab, us_link);
1238 		keg_free_slab(keg, slab, keg->uk_ipers);
1239 	}
1240 }
1241 
1242 static void
1243 zone_reclaim(uma_zone_t zone, int waitok, bool drain)
1244 {
1245 
1246 	/*
1247 	 * Set draining to interlock with zone_dtor() so we can release our
1248 	 * locks as we go.  Only dtor() should do a WAITOK call since it
1249 	 * is the only call that knows the structure will still be available
1250 	 * when it wakes up.
1251 	 */
1252 	ZONE_LOCK(zone);
1253 	while (zone->uz_flags & UMA_ZFLAG_RECLAIMING) {
1254 		if (waitok == M_NOWAIT)
1255 			goto out;
1256 		msleep(zone, &zone->uz_lock, PVM, "zonedrain", 1);
1257 	}
1258 	zone->uz_flags |= UMA_ZFLAG_RECLAIMING;
1259 	ZONE_UNLOCK(zone);
1260 	bucket_cache_reclaim(zone, drain);
1261 
1262 	/*
1263 	 * The DRAINING flag protects us from being freed while
1264 	 * we're running.  Normally the uma_rwlock would protect us but we
1265 	 * must be able to release and acquire the right lock for each keg.
1266 	 */
1267 	if ((zone->uz_flags & UMA_ZFLAG_CACHE) == 0)
1268 		keg_drain(zone->uz_keg);
1269 	ZONE_LOCK(zone);
1270 	zone->uz_flags &= ~UMA_ZFLAG_RECLAIMING;
1271 	wakeup(zone);
1272 out:
1273 	ZONE_UNLOCK(zone);
1274 }
1275 
1276 static void
1277 zone_drain(uma_zone_t zone, void *unused)
1278 {
1279 
1280 	zone_reclaim(zone, M_NOWAIT, true);
1281 }
1282 
1283 static void
1284 zone_trim(uma_zone_t zone, void *unused)
1285 {
1286 
1287 	zone_reclaim(zone, M_NOWAIT, false);
1288 }
1289 
1290 /*
1291  * Allocate a new slab for a keg and inserts it into the partial slab list.
1292  * The keg should be unlocked on entry.  If the allocation succeeds it will
1293  * be locked on return.
1294  *
1295  * Arguments:
1296  *	flags   Wait flags for the item initialization routine
1297  *	aflags  Wait flags for the slab allocation
1298  *
1299  * Returns:
1300  *	The slab that was allocated or NULL if there is no memory and the
1301  *	caller specified M_NOWAIT.
1302  */
1303 static uma_slab_t
1304 keg_alloc_slab(uma_keg_t keg, uma_zone_t zone, int domain, int flags,
1305     int aflags)
1306 {
1307 	uma_domain_t dom;
1308 	uma_alloc allocf;
1309 	uma_slab_t slab;
1310 	unsigned long size;
1311 	uint8_t *mem;
1312 	uint8_t sflags;
1313 	int i;
1314 
1315 	KASSERT(domain >= 0 && domain < vm_ndomains,
1316 	    ("keg_alloc_slab: domain %d out of range", domain));
1317 
1318 	allocf = keg->uk_allocf;
1319 	slab = NULL;
1320 	mem = NULL;
1321 	if (keg->uk_flags & UMA_ZFLAG_OFFPAGE) {
1322 		uma_hash_slab_t hslab;
1323 		hslab = zone_alloc_item(slabzone(keg->uk_ipers), NULL,
1324 		    domain, aflags);
1325 		if (hslab == NULL)
1326 			goto fail;
1327 		slab = &hslab->uhs_slab;
1328 	}
1329 
1330 	/*
1331 	 * This reproduces the old vm_zone behavior of zero filling pages the
1332 	 * first time they are added to a zone.
1333 	 *
1334 	 * Malloced items are zeroed in uma_zalloc.
1335 	 */
1336 
1337 	if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
1338 		aflags |= M_ZERO;
1339 	else
1340 		aflags &= ~M_ZERO;
1341 
1342 	if (keg->uk_flags & UMA_ZONE_NODUMP)
1343 		aflags |= M_NODUMP;
1344 
1345 	/* zone is passed for legacy reasons. */
1346 	size = keg->uk_ppera * PAGE_SIZE;
1347 	mem = allocf(zone, size, domain, &sflags, aflags);
1348 	if (mem == NULL) {
1349 		if (keg->uk_flags & UMA_ZFLAG_OFFPAGE)
1350 			zone_free_item(slabzone(keg->uk_ipers),
1351 			    slab_tohashslab(slab), NULL, SKIP_NONE);
1352 		goto fail;
1353 	}
1354 	uma_total_inc(size);
1355 
1356 	/* For HASH zones all pages go to the same uma_domain. */
1357 	if ((keg->uk_flags & UMA_ZFLAG_HASH) != 0)
1358 		domain = 0;
1359 
1360 	/* Point the slab into the allocated memory */
1361 	if (!(keg->uk_flags & UMA_ZFLAG_OFFPAGE))
1362 		slab = (uma_slab_t )(mem + keg->uk_pgoff);
1363 	else
1364 		slab_tohashslab(slab)->uhs_data = mem;
1365 
1366 	if (keg->uk_flags & UMA_ZFLAG_VTOSLAB)
1367 		for (i = 0; i < keg->uk_ppera; i++)
1368 			vsetzoneslab((vm_offset_t)mem + (i * PAGE_SIZE),
1369 			    zone, slab);
1370 
1371 	slab->us_freecount = keg->uk_ipers;
1372 	slab->us_flags = sflags;
1373 	slab->us_domain = domain;
1374 
1375 	BIT_FILL(keg->uk_ipers, &slab->us_free);
1376 #ifdef INVARIANTS
1377 	BIT_ZERO(keg->uk_ipers, slab_dbg_bits(slab, keg));
1378 #endif
1379 
1380 	if (keg->uk_init != NULL) {
1381 		for (i = 0; i < keg->uk_ipers; i++)
1382 			if (keg->uk_init(slab_item(slab, keg, i),
1383 			    keg->uk_size, flags) != 0)
1384 				break;
1385 		if (i != keg->uk_ipers) {
1386 			keg_free_slab(keg, slab, i);
1387 			goto fail;
1388 		}
1389 	}
1390 	KEG_LOCK(keg, domain);
1391 
1392 	CTR3(KTR_UMA, "keg_alloc_slab: allocated slab %p for %s(%p)",
1393 	    slab, keg->uk_name, keg);
1394 
1395 	if (keg->uk_flags & UMA_ZFLAG_HASH)
1396 		UMA_HASH_INSERT(&keg->uk_hash, slab, mem);
1397 
1398 	/*
1399 	 * If we got a slab here it's safe to mark it partially used
1400 	 * and return.  We assume that the caller is going to remove
1401 	 * at least one item.
1402 	 */
1403 	dom = &keg->uk_domain[domain];
1404 	LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
1405 	dom->ud_pages += keg->uk_ppera;
1406 	dom->ud_free += keg->uk_ipers;
1407 
1408 	return (slab);
1409 
1410 fail:
1411 	return (NULL);
1412 }
1413 
1414 /*
1415  * This function is intended to be used early on in place of page_alloc() so
1416  * that we may use the boot time page cache to satisfy allocations before
1417  * the VM is ready.
1418  */
1419 static void *
1420 startup_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
1421     int wait)
1422 {
1423 	vm_paddr_t pa;
1424 	vm_page_t m;
1425 	void *mem;
1426 	int pages;
1427 	int i;
1428 
1429 	pages = howmany(bytes, PAGE_SIZE);
1430 	KASSERT(pages > 0, ("%s can't reserve 0 pages", __func__));
1431 
1432 	*pflag = UMA_SLAB_BOOT;
1433 	m = vm_page_alloc_contig_domain(NULL, 0, domain,
1434 	    malloc2vm_flags(wait) | VM_ALLOC_NOOBJ | VM_ALLOC_WIRED, pages,
1435 	    (vm_paddr_t)0, ~(vm_paddr_t)0, 1, 0, VM_MEMATTR_DEFAULT);
1436 	if (m == NULL)
1437 		return (NULL);
1438 
1439 	pa = VM_PAGE_TO_PHYS(m);
1440 	for (i = 0; i < pages; i++, pa += PAGE_SIZE) {
1441 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) || \
1442     defined(__riscv) || defined(__powerpc64__)
1443 		if ((wait & M_NODUMP) == 0)
1444 			dump_add_page(pa);
1445 #endif
1446 	}
1447 	/* Allocate KVA and indirectly advance bootmem. */
1448 	mem = (void *)pmap_map(&bootmem, m->phys_addr,
1449 	    m->phys_addr + (pages * PAGE_SIZE), VM_PROT_READ | VM_PROT_WRITE);
1450         if ((wait & M_ZERO) != 0)
1451                 bzero(mem, pages * PAGE_SIZE);
1452 
1453         return (mem);
1454 }
1455 
1456 static void
1457 startup_free(void *mem, vm_size_t bytes)
1458 {
1459 	vm_offset_t va;
1460 	vm_page_t m;
1461 
1462 	va = (vm_offset_t)mem;
1463 	m = PHYS_TO_VM_PAGE(pmap_kextract(va));
1464 	pmap_remove(kernel_pmap, va, va + bytes);
1465 	for (; bytes != 0; bytes -= PAGE_SIZE, m++) {
1466 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) || \
1467     defined(__riscv) || defined(__powerpc64__)
1468 		dump_drop_page(VM_PAGE_TO_PHYS(m));
1469 #endif
1470 		vm_page_unwire_noq(m);
1471 		vm_page_free(m);
1472 	}
1473 }
1474 
1475 /*
1476  * Allocates a number of pages from the system
1477  *
1478  * Arguments:
1479  *	bytes  The number of bytes requested
1480  *	wait  Shall we wait?
1481  *
1482  * Returns:
1483  *	A pointer to the alloced memory or possibly
1484  *	NULL if M_NOWAIT is set.
1485  */
1486 static void *
1487 page_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
1488     int wait)
1489 {
1490 	void *p;	/* Returned page */
1491 
1492 	*pflag = UMA_SLAB_KERNEL;
1493 	p = (void *)kmem_malloc_domainset(DOMAINSET_FIXED(domain), bytes, wait);
1494 
1495 	return (p);
1496 }
1497 
1498 static void *
1499 pcpu_page_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
1500     int wait)
1501 {
1502 	struct pglist alloctail;
1503 	vm_offset_t addr, zkva;
1504 	int cpu, flags;
1505 	vm_page_t p, p_next;
1506 #ifdef NUMA
1507 	struct pcpu *pc;
1508 #endif
1509 
1510 	MPASS(bytes == (mp_maxid + 1) * PAGE_SIZE);
1511 
1512 	TAILQ_INIT(&alloctail);
1513 	flags = VM_ALLOC_SYSTEM | VM_ALLOC_WIRED | VM_ALLOC_NOOBJ |
1514 	    malloc2vm_flags(wait);
1515 	*pflag = UMA_SLAB_KERNEL;
1516 	for (cpu = 0; cpu <= mp_maxid; cpu++) {
1517 		if (CPU_ABSENT(cpu)) {
1518 			p = vm_page_alloc(NULL, 0, flags);
1519 		} else {
1520 #ifndef NUMA
1521 			p = vm_page_alloc(NULL, 0, flags);
1522 #else
1523 			pc = pcpu_find(cpu);
1524 			if (__predict_false(VM_DOMAIN_EMPTY(pc->pc_domain)))
1525 				p = NULL;
1526 			else
1527 				p = vm_page_alloc_domain(NULL, 0,
1528 				    pc->pc_domain, flags);
1529 			if (__predict_false(p == NULL))
1530 				p = vm_page_alloc(NULL, 0, flags);
1531 #endif
1532 		}
1533 		if (__predict_false(p == NULL))
1534 			goto fail;
1535 		TAILQ_INSERT_TAIL(&alloctail, p, listq);
1536 	}
1537 	if ((addr = kva_alloc(bytes)) == 0)
1538 		goto fail;
1539 	zkva = addr;
1540 	TAILQ_FOREACH(p, &alloctail, listq) {
1541 		pmap_qenter(zkva, &p, 1);
1542 		zkva += PAGE_SIZE;
1543 	}
1544 	return ((void*)addr);
1545 fail:
1546 	TAILQ_FOREACH_SAFE(p, &alloctail, listq, p_next) {
1547 		vm_page_unwire_noq(p);
1548 		vm_page_free(p);
1549 	}
1550 	return (NULL);
1551 }
1552 
1553 /*
1554  * Allocates a number of pages from within an object
1555  *
1556  * Arguments:
1557  *	bytes  The number of bytes requested
1558  *	wait   Shall we wait?
1559  *
1560  * Returns:
1561  *	A pointer to the alloced memory or possibly
1562  *	NULL if M_NOWAIT is set.
1563  */
1564 static void *
1565 noobj_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *flags,
1566     int wait)
1567 {
1568 	TAILQ_HEAD(, vm_page) alloctail;
1569 	u_long npages;
1570 	vm_offset_t retkva, zkva;
1571 	vm_page_t p, p_next;
1572 	uma_keg_t keg;
1573 
1574 	TAILQ_INIT(&alloctail);
1575 	keg = zone->uz_keg;
1576 
1577 	npages = howmany(bytes, PAGE_SIZE);
1578 	while (npages > 0) {
1579 		p = vm_page_alloc_domain(NULL, 0, domain, VM_ALLOC_INTERRUPT |
1580 		    VM_ALLOC_WIRED | VM_ALLOC_NOOBJ |
1581 		    ((wait & M_WAITOK) != 0 ? VM_ALLOC_WAITOK :
1582 		    VM_ALLOC_NOWAIT));
1583 		if (p != NULL) {
1584 			/*
1585 			 * Since the page does not belong to an object, its
1586 			 * listq is unused.
1587 			 */
1588 			TAILQ_INSERT_TAIL(&alloctail, p, listq);
1589 			npages--;
1590 			continue;
1591 		}
1592 		/*
1593 		 * Page allocation failed, free intermediate pages and
1594 		 * exit.
1595 		 */
1596 		TAILQ_FOREACH_SAFE(p, &alloctail, listq, p_next) {
1597 			vm_page_unwire_noq(p);
1598 			vm_page_free(p);
1599 		}
1600 		return (NULL);
1601 	}
1602 	*flags = UMA_SLAB_PRIV;
1603 	zkva = keg->uk_kva +
1604 	    atomic_fetchadd_long(&keg->uk_offset, round_page(bytes));
1605 	retkva = zkva;
1606 	TAILQ_FOREACH(p, &alloctail, listq) {
1607 		pmap_qenter(zkva, &p, 1);
1608 		zkva += PAGE_SIZE;
1609 	}
1610 
1611 	return ((void *)retkva);
1612 }
1613 
1614 /*
1615  * Frees a number of pages to the system
1616  *
1617  * Arguments:
1618  *	mem   A pointer to the memory to be freed
1619  *	size  The size of the memory being freed
1620  *	flags The original p->us_flags field
1621  *
1622  * Returns:
1623  *	Nothing
1624  */
1625 static void
1626 page_free(void *mem, vm_size_t size, uint8_t flags)
1627 {
1628 
1629 	if ((flags & UMA_SLAB_BOOT) != 0) {
1630 		startup_free(mem, size);
1631 		return;
1632 	}
1633 
1634 	if ((flags & UMA_SLAB_KERNEL) == 0)
1635 		panic("UMA: page_free used with invalid flags %x", flags);
1636 
1637 	kmem_free((vm_offset_t)mem, size);
1638 }
1639 
1640 /*
1641  * Frees pcpu zone allocations
1642  *
1643  * Arguments:
1644  *	mem   A pointer to the memory to be freed
1645  *	size  The size of the memory being freed
1646  *	flags The original p->us_flags field
1647  *
1648  * Returns:
1649  *	Nothing
1650  */
1651 static void
1652 pcpu_page_free(void *mem, vm_size_t size, uint8_t flags)
1653 {
1654 	vm_offset_t sva, curva;
1655 	vm_paddr_t paddr;
1656 	vm_page_t m;
1657 
1658 	MPASS(size == (mp_maxid+1)*PAGE_SIZE);
1659 	sva = (vm_offset_t)mem;
1660 	for (curva = sva; curva < sva + size; curva += PAGE_SIZE) {
1661 		paddr = pmap_kextract(curva);
1662 		m = PHYS_TO_VM_PAGE(paddr);
1663 		vm_page_unwire_noq(m);
1664 		vm_page_free(m);
1665 	}
1666 	pmap_qremove(sva, size >> PAGE_SHIFT);
1667 	kva_free(sva, size);
1668 }
1669 
1670 
1671 /*
1672  * Zero fill initializer
1673  *
1674  * Arguments/Returns follow uma_init specifications
1675  */
1676 static int
1677 zero_init(void *mem, int size, int flags)
1678 {
1679 	bzero(mem, size);
1680 	return (0);
1681 }
1682 
1683 #ifdef INVARIANTS
1684 struct noslabbits *
1685 slab_dbg_bits(uma_slab_t slab, uma_keg_t keg)
1686 {
1687 
1688 	return ((void *)((char *)&slab->us_free + BITSET_SIZE(keg->uk_ipers)));
1689 }
1690 #endif
1691 
1692 /*
1693  * Actual size of embedded struct slab (!OFFPAGE).
1694  */
1695 size_t
1696 slab_sizeof(int nitems)
1697 {
1698 	size_t s;
1699 
1700 	s = sizeof(struct uma_slab) + BITSET_SIZE(nitems) * SLAB_BITSETS;
1701 	return (roundup(s, UMA_ALIGN_PTR + 1));
1702 }
1703 
1704 /*
1705  * Size of memory for embedded slabs (!OFFPAGE).
1706  */
1707 size_t
1708 slab_space(int nitems)
1709 {
1710 	return (UMA_SLAB_SIZE - slab_sizeof(nitems));
1711 }
1712 
1713 #define	UMA_FIXPT_SHIFT	31
1714 #define	UMA_FRAC_FIXPT(n, d)						\
1715 	((uint32_t)(((uint64_t)(n) << UMA_FIXPT_SHIFT) / (d)))
1716 #define	UMA_FIXPT_PCT(f)						\
1717 	((u_int)(((uint64_t)100 * (f)) >> UMA_FIXPT_SHIFT))
1718 #define	UMA_PCT_FIXPT(pct)	UMA_FRAC_FIXPT((pct), 100)
1719 #define	UMA_MIN_EFF	UMA_PCT_FIXPT(100 - UMA_MAX_WASTE)
1720 
1721 /*
1722  * Compute the number of items that will fit in a slab.  If hdr is true, the
1723  * item count may be limited to provide space in the slab for an inline slab
1724  * header.  Otherwise, all slab space will be provided for item storage.
1725  */
1726 static u_int
1727 slab_ipers_hdr(u_int size, u_int rsize, u_int slabsize, bool hdr)
1728 {
1729 	u_int ipers;
1730 	u_int padpi;
1731 
1732 	/* The padding between items is not needed after the last item. */
1733 	padpi = rsize - size;
1734 
1735 	if (hdr) {
1736 		/*
1737 		 * Start with the maximum item count and remove items until
1738 		 * the slab header first alongside the allocatable memory.
1739 		 */
1740 		for (ipers = MIN(SLAB_MAX_SETSIZE,
1741 		    (slabsize + padpi - slab_sizeof(1)) / rsize);
1742 		    ipers > 0 &&
1743 		    ipers * rsize - padpi + slab_sizeof(ipers) > slabsize;
1744 		    ipers--)
1745 			continue;
1746 	} else {
1747 		ipers = MIN((slabsize + padpi) / rsize, SLAB_MAX_SETSIZE);
1748 	}
1749 
1750 	return (ipers);
1751 }
1752 
1753 /*
1754  * Compute the number of items that will fit in a slab for a startup zone.
1755  */
1756 int
1757 slab_ipers(size_t size, int align)
1758 {
1759 	int rsize;
1760 
1761 	rsize = roundup(size, align + 1); /* Assume no CACHESPREAD */
1762 	return (slab_ipers_hdr(size, rsize, UMA_SLAB_SIZE, true));
1763 }
1764 
1765 /*
1766  * Determine the format of a uma keg.  This determines where the slab header
1767  * will be placed (inline or offpage) and calculates ipers, rsize, and ppera.
1768  *
1769  * Arguments
1770  *	keg  The zone we should initialize
1771  *
1772  * Returns
1773  *	Nothing
1774  */
1775 static void
1776 keg_layout(uma_keg_t keg)
1777 {
1778 	u_int alignsize;
1779 	u_int eff;
1780 	u_int eff_offpage;
1781 	u_int format;
1782 	u_int ipers;
1783 	u_int ipers_offpage;
1784 	u_int pages;
1785 	u_int rsize;
1786 	u_int slabsize;
1787 
1788 	KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0 ||
1789 	    (keg->uk_size <= UMA_PCPU_ALLOC_SIZE &&
1790 	     (keg->uk_flags & UMA_ZONE_CACHESPREAD) == 0),
1791 	    ("%s: cannot configure for PCPU: keg=%s, size=%u, flags=0x%b",
1792 	     __func__, keg->uk_name, keg->uk_size, keg->uk_flags,
1793 	     PRINT_UMA_ZFLAGS));
1794 	KASSERT((keg->uk_flags &
1795 	    (UMA_ZFLAG_INTERNAL | UMA_ZFLAG_CACHEONLY)) == 0 ||
1796 	    (keg->uk_flags & (UMA_ZONE_NOTOUCH | UMA_ZONE_PCPU)) == 0,
1797 	    ("%s: incompatible flags 0x%b", __func__, keg->uk_flags,
1798 	     PRINT_UMA_ZFLAGS));
1799 
1800 	alignsize = keg->uk_align + 1;
1801 	format = 0;
1802 	ipers = 0;
1803 
1804 	/*
1805 	 * Calculate the size of each allocation (rsize) according to
1806 	 * alignment.  If the requested size is smaller than we have
1807 	 * allocation bits for we round it up.
1808 	 */
1809 	rsize = MAX(keg->uk_size, UMA_SMALLEST_UNIT);
1810 	rsize = roundup2(rsize, alignsize);
1811 
1812 	if ((keg->uk_flags & UMA_ZONE_PCPU) != 0) {
1813 		slabsize = UMA_PCPU_ALLOC_SIZE;
1814 		pages = mp_maxid + 1;
1815 	} else if ((keg->uk_flags & UMA_ZONE_CACHESPREAD) != 0) {
1816 		/*
1817 		 * We want one item to start on every align boundary in a page.
1818 		 * To do this we will span pages.  We will also extend the item
1819 		 * by the size of align if it is an even multiple of align.
1820 		 * Otherwise, it would fall on the same boundary every time.
1821 		 */
1822 		if ((rsize & alignsize) == 0)
1823 			rsize += alignsize;
1824 		slabsize = rsize * (PAGE_SIZE / alignsize);
1825 		slabsize = MIN(slabsize, rsize * SLAB_MAX_SETSIZE);
1826 		slabsize = MIN(slabsize, UMA_CACHESPREAD_MAX_SIZE);
1827 		pages = howmany(slabsize, PAGE_SIZE);
1828 		slabsize = ptoa(pages);
1829 	} else {
1830 		/*
1831 		 * Choose a slab size of as many pages as it takes to represent
1832 		 * a single item.  We will then try to fit as many additional
1833 		 * items into the slab as possible.  At some point, we may want
1834 		 * to increase the slab size for awkward item sizes in order to
1835 		 * increase efficiency.
1836 		 */
1837 		pages = howmany(keg->uk_size, PAGE_SIZE);
1838 		slabsize = ptoa(pages);
1839 	}
1840 
1841 	/* Evaluate an inline slab layout. */
1842 	if ((keg->uk_flags & (UMA_ZONE_NOTOUCH | UMA_ZONE_PCPU)) == 0)
1843 		ipers = slab_ipers_hdr(keg->uk_size, rsize, slabsize, true);
1844 
1845 	/* TODO: vm_page-embedded slab. */
1846 
1847 	/*
1848 	 * We can't do OFFPAGE if we're internal or if we've been
1849 	 * asked to not go to the VM for buckets.  If we do this we
1850 	 * may end up going to the VM  for slabs which we do not
1851 	 * want to do if we're UMA_ZFLAG_CACHEONLY as a result
1852 	 * of UMA_ZONE_VM, which clearly forbids it.
1853 	 */
1854 	if ((keg->uk_flags &
1855 	    (UMA_ZFLAG_INTERNAL | UMA_ZFLAG_CACHEONLY)) != 0) {
1856 		if (ipers == 0) {
1857 			/* We need an extra page for the slab header. */
1858 			pages++;
1859 			slabsize = ptoa(pages);
1860 			ipers = slab_ipers_hdr(keg->uk_size, rsize, slabsize,
1861 			    true);
1862 		}
1863 		goto out;
1864 	}
1865 
1866 	/*
1867 	 * See if using an OFFPAGE slab will improve our efficiency.
1868 	 * Only do this if we are below our efficiency threshold.
1869 	 *
1870 	 * XXX We could try growing slabsize to limit max waste as well.
1871 	 * Historically this was not done because the VM could not
1872 	 * efficiently handle contiguous allocations.
1873 	 */
1874 	eff = UMA_FRAC_FIXPT(ipers * rsize, slabsize);
1875 	ipers_offpage = slab_ipers_hdr(keg->uk_size, rsize, slabsize, false);
1876 	eff_offpage = UMA_FRAC_FIXPT(ipers_offpage * rsize,
1877 	    slabsize + slabzone(ipers_offpage)->uz_keg->uk_rsize);
1878 	if (ipers == 0 || (eff < UMA_MIN_EFF && eff < eff_offpage)) {
1879 		CTR5(KTR_UMA, "UMA decided we need offpage slab headers for "
1880 		    "keg: %s(%p), minimum efficiency allowed = %u%%, "
1881 		    "old efficiency = %u%%, offpage efficiency = %u%%",
1882 		    keg->uk_name, keg, UMA_FIXPT_PCT(UMA_MIN_EFF),
1883 		    UMA_FIXPT_PCT(eff), UMA_FIXPT_PCT(eff_offpage));
1884 		format = UMA_ZFLAG_OFFPAGE;
1885 		ipers = ipers_offpage;
1886 	}
1887 
1888 out:
1889 	/*
1890 	 * How do we find the slab header if it is offpage or if not all item
1891 	 * start addresses are in the same page?  We could solve the latter
1892 	 * case with vaddr alignment, but we don't.
1893 	 */
1894 	if ((format & UMA_ZFLAG_OFFPAGE) != 0 ||
1895 	    (ipers - 1) * rsize >= PAGE_SIZE) {
1896 		if ((keg->uk_flags & UMA_ZONE_NOTPAGE) != 0)
1897 			format |= UMA_ZFLAG_HASH;
1898 		else
1899 			format |= UMA_ZFLAG_VTOSLAB;
1900 	}
1901 	keg->uk_ipers = ipers;
1902 	keg->uk_rsize = rsize;
1903 	keg->uk_flags |= format;
1904 	keg->uk_ppera = pages;
1905 	CTR6(KTR_UMA, "%s: keg=%s, flags=%#x, rsize=%u, ipers=%u, ppera=%u",
1906 	    __func__, keg->uk_name, keg->uk_flags, rsize, ipers, pages);
1907 	KASSERT(keg->uk_ipers > 0 && keg->uk_ipers <= SLAB_MAX_SETSIZE,
1908 	    ("%s: keg=%s, flags=0x%b, rsize=%u, ipers=%u, ppera=%u", __func__,
1909 	     keg->uk_name, keg->uk_flags, PRINT_UMA_ZFLAGS, rsize, ipers,
1910 	     pages));
1911 }
1912 
1913 /*
1914  * Keg header ctor.  This initializes all fields, locks, etc.  And inserts
1915  * the keg onto the global keg list.
1916  *
1917  * Arguments/Returns follow uma_ctor specifications
1918  *	udata  Actually uma_kctor_args
1919  */
1920 static int
1921 keg_ctor(void *mem, int size, void *udata, int flags)
1922 {
1923 	struct uma_kctor_args *arg = udata;
1924 	uma_keg_t keg = mem;
1925 	uma_zone_t zone;
1926 	int i;
1927 
1928 	bzero(keg, size);
1929 	keg->uk_size = arg->size;
1930 	keg->uk_init = arg->uminit;
1931 	keg->uk_fini = arg->fini;
1932 	keg->uk_align = arg->align;
1933 	keg->uk_reserve = 0;
1934 	keg->uk_flags = arg->flags;
1935 
1936 	/*
1937 	 * We use a global round-robin policy by default.  Zones with
1938 	 * UMA_ZONE_FIRSTTOUCH set will use first-touch instead, in which
1939 	 * case the iterator is never run.
1940 	 */
1941 	keg->uk_dr.dr_policy = DOMAINSET_RR();
1942 	keg->uk_dr.dr_iter = 0;
1943 
1944 	/*
1945 	 * The master zone is passed to us at keg-creation time.
1946 	 */
1947 	zone = arg->zone;
1948 	keg->uk_name = zone->uz_name;
1949 
1950 	if (arg->flags & UMA_ZONE_VM)
1951 		keg->uk_flags |= UMA_ZFLAG_CACHEONLY;
1952 
1953 	if (arg->flags & UMA_ZONE_ZINIT)
1954 		keg->uk_init = zero_init;
1955 
1956 	if (arg->flags & UMA_ZONE_MALLOC)
1957 		keg->uk_flags |= UMA_ZFLAG_VTOSLAB;
1958 
1959 #ifndef SMP
1960 	keg->uk_flags &= ~UMA_ZONE_PCPU;
1961 #endif
1962 
1963 	keg_layout(keg);
1964 
1965 	/*
1966 	 * Use a first-touch NUMA policy for all kegs that pmap_extract()
1967 	 * will work on with the exception of critical VM structures
1968 	 * necessary for paging.
1969 	 *
1970 	 * Zones may override the default by specifying either.
1971 	 */
1972 #ifdef NUMA
1973 	if ((keg->uk_flags &
1974 	    (UMA_ZFLAG_HASH | UMA_ZONE_VM | UMA_ZONE_ROUNDROBIN)) == 0)
1975 		keg->uk_flags |= UMA_ZONE_FIRSTTOUCH;
1976 	else if ((keg->uk_flags & UMA_ZONE_FIRSTTOUCH) == 0)
1977 		keg->uk_flags |= UMA_ZONE_ROUNDROBIN;
1978 #endif
1979 
1980 	/*
1981 	 * If we haven't booted yet we need allocations to go through the
1982 	 * startup cache until the vm is ready.
1983 	 */
1984 #ifdef UMA_MD_SMALL_ALLOC
1985 	if (keg->uk_ppera == 1)
1986 		keg->uk_allocf = uma_small_alloc;
1987 	else
1988 #endif
1989 	if (booted < BOOT_KVA)
1990 		keg->uk_allocf = startup_alloc;
1991 	else if (keg->uk_flags & UMA_ZONE_PCPU)
1992 		keg->uk_allocf = pcpu_page_alloc;
1993 	else
1994 		keg->uk_allocf = page_alloc;
1995 #ifdef UMA_MD_SMALL_ALLOC
1996 	if (keg->uk_ppera == 1)
1997 		keg->uk_freef = uma_small_free;
1998 	else
1999 #endif
2000 	if (keg->uk_flags & UMA_ZONE_PCPU)
2001 		keg->uk_freef = pcpu_page_free;
2002 	else
2003 		keg->uk_freef = page_free;
2004 
2005 	/*
2006 	 * Initialize keg's locks.
2007 	 */
2008 	for (i = 0; i < vm_ndomains; i++)
2009 		KEG_LOCK_INIT(keg, i, (arg->flags & UMA_ZONE_MTXCLASS));
2010 
2011 	/*
2012 	 * If we're putting the slab header in the actual page we need to
2013 	 * figure out where in each page it goes.  See slab_sizeof
2014 	 * definition.
2015 	 */
2016 	if (!(keg->uk_flags & UMA_ZFLAG_OFFPAGE)) {
2017 		size_t shsize;
2018 
2019 		shsize = slab_sizeof(keg->uk_ipers);
2020 		keg->uk_pgoff = (PAGE_SIZE * keg->uk_ppera) - shsize;
2021 		/*
2022 		 * The only way the following is possible is if with our
2023 		 * UMA_ALIGN_PTR adjustments we are now bigger than
2024 		 * UMA_SLAB_SIZE.  I haven't checked whether this is
2025 		 * mathematically possible for all cases, so we make
2026 		 * sure here anyway.
2027 		 */
2028 		KASSERT(keg->uk_pgoff + shsize <= PAGE_SIZE * keg->uk_ppera,
2029 		    ("zone %s ipers %d rsize %d size %d slab won't fit",
2030 		    zone->uz_name, keg->uk_ipers, keg->uk_rsize, keg->uk_size));
2031 	}
2032 
2033 	if (keg->uk_flags & UMA_ZFLAG_HASH)
2034 		hash_alloc(&keg->uk_hash, 0);
2035 
2036 	CTR3(KTR_UMA, "keg_ctor %p zone %s(%p)", keg, zone->uz_name, zone);
2037 
2038 	LIST_INSERT_HEAD(&keg->uk_zones, zone, uz_link);
2039 
2040 	rw_wlock(&uma_rwlock);
2041 	LIST_INSERT_HEAD(&uma_kegs, keg, uk_link);
2042 	rw_wunlock(&uma_rwlock);
2043 	return (0);
2044 }
2045 
2046 static void
2047 zone_kva_available(uma_zone_t zone, void *unused)
2048 {
2049 	uma_keg_t keg;
2050 
2051 	if ((zone->uz_flags & UMA_ZFLAG_CACHE) != 0)
2052 		return;
2053 	KEG_GET(zone, keg);
2054 	if (keg->uk_allocf == startup_alloc)
2055 		keg->uk_allocf = page_alloc;
2056 }
2057 
2058 static void
2059 zone_alloc_counters(uma_zone_t zone, void *unused)
2060 {
2061 
2062 	zone->uz_allocs = counter_u64_alloc(M_WAITOK);
2063 	zone->uz_frees = counter_u64_alloc(M_WAITOK);
2064 	zone->uz_fails = counter_u64_alloc(M_WAITOK);
2065 }
2066 
2067 static void
2068 zone_alloc_sysctl(uma_zone_t zone, void *unused)
2069 {
2070 	uma_zone_domain_t zdom;
2071 	uma_domain_t dom;
2072 	uma_keg_t keg;
2073 	struct sysctl_oid *oid, *domainoid;
2074 	int domains, i, cnt;
2075 	static const char *nokeg = "cache zone";
2076 	char *c;
2077 
2078 	/*
2079 	 * Make a sysctl safe copy of the zone name by removing
2080 	 * any special characters and handling dups by appending
2081 	 * an index.
2082 	 */
2083 	if (zone->uz_namecnt != 0) {
2084 		/* Count the number of decimal digits and '_' separator. */
2085 		for (i = 1, cnt = zone->uz_namecnt; cnt != 0; i++)
2086 			cnt /= 10;
2087 		zone->uz_ctlname = malloc(strlen(zone->uz_name) + i + 1,
2088 		    M_UMA, M_WAITOK);
2089 		sprintf(zone->uz_ctlname, "%s_%d", zone->uz_name,
2090 		    zone->uz_namecnt);
2091 	} else
2092 		zone->uz_ctlname = strdup(zone->uz_name, M_UMA);
2093 	for (c = zone->uz_ctlname; *c != '\0'; c++)
2094 		if (strchr("./\\ -", *c) != NULL)
2095 			*c = '_';
2096 
2097 	/*
2098 	 * Basic parameters at the root.
2099 	 */
2100 	zone->uz_oid = SYSCTL_ADD_NODE(NULL, SYSCTL_STATIC_CHILDREN(_vm_uma),
2101 	    OID_AUTO, zone->uz_ctlname, CTLFLAG_RD, NULL, "");
2102 	oid = zone->uz_oid;
2103 	SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2104 	    "size", CTLFLAG_RD, &zone->uz_size, 0, "Allocation size");
2105 	SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2106 	    "flags", CTLFLAG_RD | CTLTYPE_STRING | CTLFLAG_MPSAFE,
2107 	    zone, 0, sysctl_handle_uma_zone_flags, "A",
2108 	    "Allocator configuration flags");
2109 	SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2110 	    "bucket_size", CTLFLAG_RD, &zone->uz_bucket_size, 0,
2111 	    "Desired per-cpu cache size");
2112 	SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2113 	    "bucket_size_max", CTLFLAG_RD, &zone->uz_bucket_size_max, 0,
2114 	    "Maximum allowed per-cpu cache size");
2115 
2116 	/*
2117 	 * keg if present.
2118 	 */
2119 	if ((zone->uz_flags & UMA_ZFLAG_HASH) == 0)
2120 		domains = vm_ndomains;
2121 	else
2122 		domains = 1;
2123 	oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid), OID_AUTO,
2124 	    "keg", CTLFLAG_RD, NULL, "");
2125 	keg = zone->uz_keg;
2126 	if ((zone->uz_flags & UMA_ZFLAG_CACHE) == 0) {
2127 		SYSCTL_ADD_CONST_STRING(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2128 		    "name", CTLFLAG_RD, keg->uk_name, "Keg name");
2129 		SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2130 		    "rsize", CTLFLAG_RD, &keg->uk_rsize, 0,
2131 		    "Real object size with alignment");
2132 		SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2133 		    "ppera", CTLFLAG_RD, &keg->uk_ppera, 0,
2134 		    "pages per-slab allocation");
2135 		SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2136 		    "ipers", CTLFLAG_RD, &keg->uk_ipers, 0,
2137 		    "items available per-slab");
2138 		SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2139 		    "align", CTLFLAG_RD, &keg->uk_align, 0,
2140 		    "item alignment mask");
2141 		SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2142 		    "efficiency", CTLFLAG_RD | CTLTYPE_INT | CTLFLAG_MPSAFE,
2143 		    keg, 0, sysctl_handle_uma_slab_efficiency, "I",
2144 		    "Slab utilization (100 - internal fragmentation %)");
2145 		domainoid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(oid),
2146 		    OID_AUTO, "domain", CTLFLAG_RD, NULL, "");
2147 		for (i = 0; i < domains; i++) {
2148 			dom = &keg->uk_domain[i];
2149 			oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(domainoid),
2150 			    OID_AUTO, VM_DOMAIN(i)->vmd_name, CTLFLAG_RD,
2151 			    NULL, "");
2152 			SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2153 			    "pages", CTLFLAG_RD, &dom->ud_pages, 0,
2154 			    "Total pages currently allocated from VM");
2155 			SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2156 			    "free", CTLFLAG_RD, &dom->ud_free, 0,
2157 			    "items free in the slab layer");
2158 		}
2159 	} else
2160 		SYSCTL_ADD_CONST_STRING(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2161 		    "name", CTLFLAG_RD, nokeg, "Keg name");
2162 
2163 	/*
2164 	 * Information about zone limits.
2165 	 */
2166 	oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid), OID_AUTO,
2167 	    "limit", CTLFLAG_RD, NULL, "");
2168 	SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2169 	    "items", CTLFLAG_RD | CTLTYPE_U64 | CTLFLAG_MPSAFE,
2170 	    zone, 0, sysctl_handle_uma_zone_items, "QU",
2171 	    "current number of allocated items if limit is set");
2172 	SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2173 	    "max_items", CTLFLAG_RD, &zone->uz_max_items, 0,
2174 	    "Maximum number of cached items");
2175 	SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2176 	    "sleepers", CTLFLAG_RD, &zone->uz_sleepers, 0,
2177 	    "Number of threads sleeping at limit");
2178 	SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2179 	    "sleeps", CTLFLAG_RD, &zone->uz_sleeps, 0,
2180 	    "Total zone limit sleeps");
2181 	SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2182 	    "bucket_max", CTLFLAG_RD, &zone->uz_bkt_max, 0,
2183 	    "Maximum number of items in the bucket cache");
2184 	SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2185 	    "bucket_cnt", CTLFLAG_RD, &zone->uz_bkt_count, 0,
2186 	    "Number of items in the bucket cache");
2187 
2188 	/*
2189 	 * Per-domain zone information.
2190 	 */
2191 	domainoid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid),
2192 	    OID_AUTO, "domain", CTLFLAG_RD, NULL, "");
2193 	if ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) == 0)
2194 		domains = 1;
2195 	for (i = 0; i < domains; i++) {
2196 		zdom = &zone->uz_domain[i];
2197 		oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(domainoid),
2198 		    OID_AUTO, VM_DOMAIN(i)->vmd_name, CTLFLAG_RD, NULL, "");
2199 		SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2200 		    "nitems", CTLFLAG_RD, &zdom->uzd_nitems,
2201 		    "number of items in this domain");
2202 		SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2203 		    "imax", CTLFLAG_RD, &zdom->uzd_imax,
2204 		    "maximum item count in this period");
2205 		SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2206 		    "imin", CTLFLAG_RD, &zdom->uzd_imin,
2207 		    "minimum item count in this period");
2208 		SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2209 		    "wss", CTLFLAG_RD, &zdom->uzd_wss,
2210 		    "Working set size");
2211 	}
2212 
2213 	/*
2214 	 * General statistics.
2215 	 */
2216 	oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid), OID_AUTO,
2217 	    "stats", CTLFLAG_RD, NULL, "");
2218 	SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2219 	    "current", CTLFLAG_RD | CTLTYPE_INT | CTLFLAG_MPSAFE,
2220 	    zone, 1, sysctl_handle_uma_zone_cur, "I",
2221 	    "Current number of allocated items");
2222 	SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2223 	    "allocs", CTLFLAG_RD | CTLTYPE_U64 | CTLFLAG_MPSAFE,
2224 	    zone, 0, sysctl_handle_uma_zone_allocs, "QU",
2225 	    "Total allocation calls");
2226 	SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2227 	    "frees", CTLFLAG_RD | CTLTYPE_U64 | CTLFLAG_MPSAFE,
2228 	    zone, 0, sysctl_handle_uma_zone_frees, "QU",
2229 	    "Total free calls");
2230 	SYSCTL_ADD_COUNTER_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2231 	    "fails", CTLFLAG_RD, &zone->uz_fails,
2232 	    "Number of allocation failures");
2233 	SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2234 	    "xdomain", CTLFLAG_RD, &zone->uz_xdomain, 0,
2235 	    "Free calls from the wrong domain");
2236 }
2237 
2238 struct uma_zone_count {
2239 	const char	*name;
2240 	int		count;
2241 };
2242 
2243 static void
2244 zone_count(uma_zone_t zone, void *arg)
2245 {
2246 	struct uma_zone_count *cnt;
2247 
2248 	cnt = arg;
2249 	/*
2250 	 * Some zones are rapidly created with identical names and
2251 	 * destroyed out of order.  This can lead to gaps in the count.
2252 	 * Use one greater than the maximum observed for this name.
2253 	 */
2254 	if (strcmp(zone->uz_name, cnt->name) == 0)
2255 		cnt->count = MAX(cnt->count,
2256 		    zone->uz_namecnt + 1);
2257 }
2258 
2259 static void
2260 zone_update_caches(uma_zone_t zone)
2261 {
2262 	int i;
2263 
2264 	for (i = 0; i <= mp_maxid; i++) {
2265 		cache_set_uz_size(&zone->uz_cpu[i], zone->uz_size);
2266 		cache_set_uz_flags(&zone->uz_cpu[i], zone->uz_flags);
2267 	}
2268 }
2269 
2270 /*
2271  * Zone header ctor.  This initializes all fields, locks, etc.
2272  *
2273  * Arguments/Returns follow uma_ctor specifications
2274  *	udata  Actually uma_zctor_args
2275  */
2276 static int
2277 zone_ctor(void *mem, int size, void *udata, int flags)
2278 {
2279 	struct uma_zone_count cnt;
2280 	struct uma_zctor_args *arg = udata;
2281 	uma_zone_t zone = mem;
2282 	uma_zone_t z;
2283 	uma_keg_t keg;
2284 	int i;
2285 
2286 	bzero(zone, size);
2287 	zone->uz_name = arg->name;
2288 	zone->uz_ctor = arg->ctor;
2289 	zone->uz_dtor = arg->dtor;
2290 	zone->uz_init = NULL;
2291 	zone->uz_fini = NULL;
2292 	zone->uz_sleeps = 0;
2293 	zone->uz_xdomain = 0;
2294 	zone->uz_bucket_size = 0;
2295 	zone->uz_bucket_size_min = 0;
2296 	zone->uz_bucket_size_max = BUCKET_MAX;
2297 	zone->uz_flags = 0;
2298 	zone->uz_warning = NULL;
2299 	/* The domain structures follow the cpu structures. */
2300 	zone->uz_domain =
2301 	    (struct uma_zone_domain *)&zone->uz_cpu[mp_maxid + 1];
2302 	zone->uz_bkt_max = ULONG_MAX;
2303 	timevalclear(&zone->uz_ratecheck);
2304 
2305 	/* Count the number of duplicate names. */
2306 	cnt.name = arg->name;
2307 	cnt.count = 0;
2308 	zone_foreach(zone_count, &cnt);
2309 	zone->uz_namecnt = cnt.count;
2310 	ZONE_LOCK_INIT(zone, (arg->flags & UMA_ZONE_MTXCLASS));
2311 	ZONE_CROSS_LOCK_INIT(zone);
2312 
2313 	for (i = 0; i < vm_ndomains; i++)
2314 		TAILQ_INIT(&zone->uz_domain[i].uzd_buckets);
2315 
2316 #ifdef INVARIANTS
2317 	if (arg->uminit == trash_init && arg->fini == trash_fini)
2318 		zone->uz_flags |= UMA_ZFLAG_TRASH | UMA_ZFLAG_CTORDTOR;
2319 #endif
2320 
2321 	/*
2322 	 * This is a pure cache zone, no kegs.
2323 	 */
2324 	if (arg->import) {
2325 		KASSERT((arg->flags & UMA_ZFLAG_CACHE) != 0,
2326 		    ("zone_ctor: Import specified for non-cache zone."));
2327 		if (arg->flags & UMA_ZONE_VM)
2328 			arg->flags |= UMA_ZFLAG_CACHEONLY;
2329 		zone->uz_flags = arg->flags;
2330 		zone->uz_size = arg->size;
2331 		zone->uz_import = arg->import;
2332 		zone->uz_release = arg->release;
2333 		zone->uz_arg = arg->arg;
2334 		rw_wlock(&uma_rwlock);
2335 		LIST_INSERT_HEAD(&uma_cachezones, zone, uz_link);
2336 		rw_wunlock(&uma_rwlock);
2337 		goto out;
2338 	}
2339 
2340 	/*
2341 	 * Use the regular zone/keg/slab allocator.
2342 	 */
2343 	zone->uz_import = zone_import;
2344 	zone->uz_release = zone_release;
2345 	zone->uz_arg = zone;
2346 	keg = arg->keg;
2347 
2348 	if (arg->flags & UMA_ZONE_SECONDARY) {
2349 		KASSERT((zone->uz_flags & UMA_ZONE_SECONDARY) == 0,
2350 		    ("Secondary zone requested UMA_ZFLAG_INTERNAL"));
2351 		KASSERT(arg->keg != NULL, ("Secondary zone on zero'd keg"));
2352 		zone->uz_init = arg->uminit;
2353 		zone->uz_fini = arg->fini;
2354 		zone->uz_flags |= UMA_ZONE_SECONDARY;
2355 		rw_wlock(&uma_rwlock);
2356 		ZONE_LOCK(zone);
2357 		LIST_FOREACH(z, &keg->uk_zones, uz_link) {
2358 			if (LIST_NEXT(z, uz_link) == NULL) {
2359 				LIST_INSERT_AFTER(z, zone, uz_link);
2360 				break;
2361 			}
2362 		}
2363 		ZONE_UNLOCK(zone);
2364 		rw_wunlock(&uma_rwlock);
2365 	} else if (keg == NULL) {
2366 		if ((keg = uma_kcreate(zone, arg->size, arg->uminit, arg->fini,
2367 		    arg->align, arg->flags)) == NULL)
2368 			return (ENOMEM);
2369 	} else {
2370 		struct uma_kctor_args karg;
2371 		int error;
2372 
2373 		/* We should only be here from uma_startup() */
2374 		karg.size = arg->size;
2375 		karg.uminit = arg->uminit;
2376 		karg.fini = arg->fini;
2377 		karg.align = arg->align;
2378 		karg.flags = arg->flags;
2379 		karg.zone = zone;
2380 		error = keg_ctor(arg->keg, sizeof(struct uma_keg), &karg,
2381 		    flags);
2382 		if (error)
2383 			return (error);
2384 	}
2385 
2386 	/* Inherit properties from the keg. */
2387 	zone->uz_keg = keg;
2388 	zone->uz_size = keg->uk_size;
2389 	zone->uz_flags |= (keg->uk_flags &
2390 	    (UMA_ZONE_INHERIT | UMA_ZFLAG_INHERIT));
2391 
2392 out:
2393 	if (__predict_true(booted >= BOOT_RUNNING)) {
2394 		zone_alloc_counters(zone, NULL);
2395 		zone_alloc_sysctl(zone, NULL);
2396 	} else {
2397 		zone->uz_allocs = EARLY_COUNTER;
2398 		zone->uz_frees = EARLY_COUNTER;
2399 		zone->uz_fails = EARLY_COUNTER;
2400 	}
2401 
2402 	KASSERT((arg->flags & (UMA_ZONE_MAXBUCKET | UMA_ZONE_NOBUCKET)) !=
2403 	    (UMA_ZONE_MAXBUCKET | UMA_ZONE_NOBUCKET),
2404 	    ("Invalid zone flag combination"));
2405 	if (arg->flags & UMA_ZFLAG_INTERNAL)
2406 		zone->uz_bucket_size_max = zone->uz_bucket_size = 0;
2407 	if ((arg->flags & UMA_ZONE_MAXBUCKET) != 0)
2408 		zone->uz_bucket_size = BUCKET_MAX;
2409 	else if ((arg->flags & UMA_ZONE_MINBUCKET) != 0)
2410 		zone->uz_bucket_size_max = zone->uz_bucket_size = BUCKET_MIN;
2411 	else if ((arg->flags & UMA_ZONE_NOBUCKET) != 0)
2412 		zone->uz_bucket_size = 0;
2413 	else
2414 		zone->uz_bucket_size = bucket_select(zone->uz_size);
2415 	zone->uz_bucket_size_min = zone->uz_bucket_size;
2416 	if (zone->uz_dtor != NULL || zone->uz_ctor != NULL)
2417 		zone->uz_flags |= UMA_ZFLAG_CTORDTOR;
2418 	zone_update_caches(zone);
2419 
2420 	return (0);
2421 }
2422 
2423 /*
2424  * Keg header dtor.  This frees all data, destroys locks, frees the hash
2425  * table and removes the keg from the global list.
2426  *
2427  * Arguments/Returns follow uma_dtor specifications
2428  *	udata  unused
2429  */
2430 static void
2431 keg_dtor(void *arg, int size, void *udata)
2432 {
2433 	uma_keg_t keg;
2434 	uint32_t free, pages;
2435 	int i;
2436 
2437 	keg = (uma_keg_t)arg;
2438 	free = pages = 0;
2439 	for (i = 0; i < vm_ndomains; i++) {
2440 		free += keg->uk_domain[i].ud_free;
2441 		pages += keg->uk_domain[i].ud_pages;
2442 		KEG_LOCK_FINI(keg, i);
2443 	}
2444 	if (pages != 0)
2445 		printf("Freed UMA keg (%s) was not empty (%u items). "
2446 		    " Lost %u pages of memory.\n",
2447 		    keg->uk_name ? keg->uk_name : "",
2448 		    pages / keg->uk_ppera * keg->uk_ipers - free, pages);
2449 
2450 	hash_free(&keg->uk_hash);
2451 }
2452 
2453 /*
2454  * Zone header dtor.
2455  *
2456  * Arguments/Returns follow uma_dtor specifications
2457  *	udata  unused
2458  */
2459 static void
2460 zone_dtor(void *arg, int size, void *udata)
2461 {
2462 	uma_zone_t zone;
2463 	uma_keg_t keg;
2464 
2465 	zone = (uma_zone_t)arg;
2466 
2467 	sysctl_remove_oid(zone->uz_oid, 1, 1);
2468 
2469 	if (!(zone->uz_flags & UMA_ZFLAG_INTERNAL))
2470 		cache_drain(zone);
2471 
2472 	rw_wlock(&uma_rwlock);
2473 	LIST_REMOVE(zone, uz_link);
2474 	rw_wunlock(&uma_rwlock);
2475 	/*
2476 	 * XXX there are some races here where
2477 	 * the zone can be drained but zone lock
2478 	 * released and then refilled before we
2479 	 * remove it... we dont care for now
2480 	 */
2481 	zone_reclaim(zone, M_WAITOK, true);
2482 	/*
2483 	 * We only destroy kegs from non secondary/non cache zones.
2484 	 */
2485 	if ((zone->uz_flags & (UMA_ZONE_SECONDARY | UMA_ZFLAG_CACHE)) == 0) {
2486 		keg = zone->uz_keg;
2487 		rw_wlock(&uma_rwlock);
2488 		LIST_REMOVE(keg, uk_link);
2489 		rw_wunlock(&uma_rwlock);
2490 		zone_free_item(kegs, keg, NULL, SKIP_NONE);
2491 	}
2492 	counter_u64_free(zone->uz_allocs);
2493 	counter_u64_free(zone->uz_frees);
2494 	counter_u64_free(zone->uz_fails);
2495 	free(zone->uz_ctlname, M_UMA);
2496 	ZONE_LOCK_FINI(zone);
2497 	ZONE_CROSS_LOCK_FINI(zone);
2498 }
2499 
2500 static void
2501 zone_foreach_unlocked(void (*zfunc)(uma_zone_t, void *arg), void *arg)
2502 {
2503 	uma_keg_t keg;
2504 	uma_zone_t zone;
2505 
2506 	LIST_FOREACH(keg, &uma_kegs, uk_link) {
2507 		LIST_FOREACH(zone, &keg->uk_zones, uz_link)
2508 			zfunc(zone, arg);
2509 	}
2510 	LIST_FOREACH(zone, &uma_cachezones, uz_link)
2511 		zfunc(zone, arg);
2512 }
2513 
2514 /*
2515  * Traverses every zone in the system and calls a callback
2516  *
2517  * Arguments:
2518  *	zfunc  A pointer to a function which accepts a zone
2519  *		as an argument.
2520  *
2521  * Returns:
2522  *	Nothing
2523  */
2524 static void
2525 zone_foreach(void (*zfunc)(uma_zone_t, void *arg), void *arg)
2526 {
2527 
2528 	rw_rlock(&uma_rwlock);
2529 	zone_foreach_unlocked(zfunc, arg);
2530 	rw_runlock(&uma_rwlock);
2531 }
2532 
2533 /*
2534  * Initialize the kernel memory allocator.  This is done after pages can be
2535  * allocated but before general KVA is available.
2536  */
2537 void
2538 uma_startup1(vm_offset_t virtual_avail)
2539 {
2540 	struct uma_zctor_args args;
2541 	size_t ksize, zsize, size;
2542 	uma_keg_t masterkeg;
2543 	uintptr_t m;
2544 	uint8_t pflag;
2545 
2546 	bootstart = bootmem = virtual_avail;
2547 
2548 	rw_init(&uma_rwlock, "UMA lock");
2549 	sx_init(&uma_reclaim_lock, "umareclaim");
2550 
2551 	ksize = sizeof(struct uma_keg) +
2552 	    (sizeof(struct uma_domain) * vm_ndomains);
2553 	ksize = roundup(ksize, UMA_SUPER_ALIGN);
2554 	zsize = sizeof(struct uma_zone) +
2555 	    (sizeof(struct uma_cache) * (mp_maxid + 1)) +
2556 	    (sizeof(struct uma_zone_domain) * vm_ndomains);
2557 	zsize = roundup(zsize, UMA_SUPER_ALIGN);
2558 
2559 	/* Allocate the zone of zones, zone of kegs, and zone of zones keg. */
2560 	size = (zsize * 2) + ksize;
2561 	m = (uintptr_t)startup_alloc(NULL, size, 0, &pflag, M_NOWAIT | M_ZERO);
2562 	zones = (uma_zone_t)m;
2563 	m += zsize;
2564 	kegs = (uma_zone_t)m;
2565 	m += zsize;
2566 	masterkeg = (uma_keg_t)m;
2567 
2568 	/* "manually" create the initial zone */
2569 	memset(&args, 0, sizeof(args));
2570 	args.name = "UMA Kegs";
2571 	args.size = ksize;
2572 	args.ctor = keg_ctor;
2573 	args.dtor = keg_dtor;
2574 	args.uminit = zero_init;
2575 	args.fini = NULL;
2576 	args.keg = masterkeg;
2577 	args.align = UMA_SUPER_ALIGN - 1;
2578 	args.flags = UMA_ZFLAG_INTERNAL;
2579 	zone_ctor(kegs, zsize, &args, M_WAITOK);
2580 
2581 	args.name = "UMA Zones";
2582 	args.size = zsize;
2583 	args.ctor = zone_ctor;
2584 	args.dtor = zone_dtor;
2585 	args.uminit = zero_init;
2586 	args.fini = NULL;
2587 	args.keg = NULL;
2588 	args.align = UMA_SUPER_ALIGN - 1;
2589 	args.flags = UMA_ZFLAG_INTERNAL;
2590 	zone_ctor(zones, zsize, &args, M_WAITOK);
2591 
2592 	/* Now make zones for slab headers */
2593 	slabzones[0] = uma_zcreate("UMA Slabs 0", SLABZONE0_SIZE,
2594 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
2595 	slabzones[1] = uma_zcreate("UMA Slabs 1", SLABZONE1_SIZE,
2596 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
2597 
2598 	hashzone = uma_zcreate("UMA Hash",
2599 	    sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT,
2600 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
2601 
2602 	bucket_init();
2603 }
2604 
2605 #ifndef UMA_MD_SMALL_ALLOC
2606 extern void vm_radix_reserve_kva(void);
2607 #endif
2608 
2609 /*
2610  * Advertise the availability of normal kva allocations and switch to
2611  * the default back-end allocator.  Marks the KVA we consumed on startup
2612  * as used in the map.
2613  */
2614 void
2615 uma_startup2(void)
2616 {
2617 
2618 	if (bootstart != bootmem) {
2619 		vm_map_lock(kernel_map);
2620 		(void)vm_map_insert(kernel_map, NULL, 0, bootstart, bootmem,
2621 		    VM_PROT_RW, VM_PROT_RW, MAP_NOFAULT);
2622 		vm_map_unlock(kernel_map);
2623 	}
2624 
2625 #ifndef UMA_MD_SMALL_ALLOC
2626 	/* Set up radix zone to use noobj_alloc. */
2627 	vm_radix_reserve_kva();
2628 #endif
2629 
2630 	booted = BOOT_KVA;
2631 	zone_foreach_unlocked(zone_kva_available, NULL);
2632 	bucket_enable();
2633 }
2634 
2635 /*
2636  * Finish our initialization steps.
2637  */
2638 static void
2639 uma_startup3(void)
2640 {
2641 
2642 #ifdef INVARIANTS
2643 	TUNABLE_INT_FETCH("vm.debug.divisor", &dbg_divisor);
2644 	uma_dbg_cnt = counter_u64_alloc(M_WAITOK);
2645 	uma_skip_cnt = counter_u64_alloc(M_WAITOK);
2646 #endif
2647 	zone_foreach_unlocked(zone_alloc_counters, NULL);
2648 	zone_foreach_unlocked(zone_alloc_sysctl, NULL);
2649 	callout_init(&uma_callout, 1);
2650 	callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
2651 	booted = BOOT_RUNNING;
2652 
2653 	EVENTHANDLER_REGISTER(shutdown_post_sync, uma_shutdown, NULL,
2654 	    EVENTHANDLER_PRI_FIRST);
2655 }
2656 
2657 static void
2658 uma_shutdown(void)
2659 {
2660 
2661 	booted = BOOT_SHUTDOWN;
2662 }
2663 
2664 static uma_keg_t
2665 uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini,
2666 		int align, uint32_t flags)
2667 {
2668 	struct uma_kctor_args args;
2669 
2670 	args.size = size;
2671 	args.uminit = uminit;
2672 	args.fini = fini;
2673 	args.align = (align == UMA_ALIGN_CACHE) ? uma_align_cache : align;
2674 	args.flags = flags;
2675 	args.zone = zone;
2676 	return (zone_alloc_item(kegs, &args, UMA_ANYDOMAIN, M_WAITOK));
2677 }
2678 
2679 /* Public functions */
2680 /* See uma.h */
2681 void
2682 uma_set_align(int align)
2683 {
2684 
2685 	if (align != UMA_ALIGN_CACHE)
2686 		uma_align_cache = align;
2687 }
2688 
2689 /* See uma.h */
2690 uma_zone_t
2691 uma_zcreate(const char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
2692 		uma_init uminit, uma_fini fini, int align, uint32_t flags)
2693 
2694 {
2695 	struct uma_zctor_args args;
2696 	uma_zone_t res;
2697 
2698 	KASSERT(powerof2(align + 1), ("invalid zone alignment %d for \"%s\"",
2699 	    align, name));
2700 
2701 	/* This stuff is essential for the zone ctor */
2702 	memset(&args, 0, sizeof(args));
2703 	args.name = name;
2704 	args.size = size;
2705 	args.ctor = ctor;
2706 	args.dtor = dtor;
2707 	args.uminit = uminit;
2708 	args.fini = fini;
2709 #ifdef  INVARIANTS
2710 	/*
2711 	 * Inject procedures which check for memory use after free if we are
2712 	 * allowed to scramble the memory while it is not allocated.  This
2713 	 * requires that: UMA is actually able to access the memory, no init
2714 	 * or fini procedures, no dependency on the initial value of the
2715 	 * memory, and no (legitimate) use of the memory after free.  Note,
2716 	 * the ctor and dtor do not need to be empty.
2717 	 */
2718 	if ((!(flags & (UMA_ZONE_ZINIT | UMA_ZONE_NOTOUCH |
2719 	    UMA_ZONE_NOFREE))) && uminit == NULL && fini == NULL) {
2720 		args.uminit = trash_init;
2721 		args.fini = trash_fini;
2722 	}
2723 #endif
2724 	args.align = align;
2725 	args.flags = flags;
2726 	args.keg = NULL;
2727 
2728 	sx_slock(&uma_reclaim_lock);
2729 	res = zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK);
2730 	sx_sunlock(&uma_reclaim_lock);
2731 
2732 	return (res);
2733 }
2734 
2735 /* See uma.h */
2736 uma_zone_t
2737 uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
2738 		    uma_init zinit, uma_fini zfini, uma_zone_t master)
2739 {
2740 	struct uma_zctor_args args;
2741 	uma_keg_t keg;
2742 	uma_zone_t res;
2743 
2744 	keg = master->uz_keg;
2745 	memset(&args, 0, sizeof(args));
2746 	args.name = name;
2747 	args.size = keg->uk_size;
2748 	args.ctor = ctor;
2749 	args.dtor = dtor;
2750 	args.uminit = zinit;
2751 	args.fini = zfini;
2752 	args.align = keg->uk_align;
2753 	args.flags = keg->uk_flags | UMA_ZONE_SECONDARY;
2754 	args.keg = keg;
2755 
2756 	sx_slock(&uma_reclaim_lock);
2757 	res = zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK);
2758 	sx_sunlock(&uma_reclaim_lock);
2759 
2760 	return (res);
2761 }
2762 
2763 /* See uma.h */
2764 uma_zone_t
2765 uma_zcache_create(char *name, int size, uma_ctor ctor, uma_dtor dtor,
2766 		    uma_init zinit, uma_fini zfini, uma_import zimport,
2767 		    uma_release zrelease, void *arg, int flags)
2768 {
2769 	struct uma_zctor_args args;
2770 
2771 	memset(&args, 0, sizeof(args));
2772 	args.name = name;
2773 	args.size = size;
2774 	args.ctor = ctor;
2775 	args.dtor = dtor;
2776 	args.uminit = zinit;
2777 	args.fini = zfini;
2778 	args.import = zimport;
2779 	args.release = zrelease;
2780 	args.arg = arg;
2781 	args.align = 0;
2782 	args.flags = flags | UMA_ZFLAG_CACHE;
2783 
2784 	return (zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK));
2785 }
2786 
2787 /* See uma.h */
2788 void
2789 uma_zdestroy(uma_zone_t zone)
2790 {
2791 
2792 	/*
2793 	 * Large slabs are expensive to reclaim, so don't bother doing
2794 	 * unnecessary work if we're shutting down.
2795 	 */
2796 	if (booted == BOOT_SHUTDOWN &&
2797 	    zone->uz_fini == NULL && zone->uz_release == zone_release)
2798 		return;
2799 	sx_slock(&uma_reclaim_lock);
2800 	zone_free_item(zones, zone, NULL, SKIP_NONE);
2801 	sx_sunlock(&uma_reclaim_lock);
2802 }
2803 
2804 void
2805 uma_zwait(uma_zone_t zone)
2806 {
2807 	void *item;
2808 
2809 	item = uma_zalloc_arg(zone, NULL, M_WAITOK);
2810 	uma_zfree(zone, item);
2811 }
2812 
2813 void *
2814 uma_zalloc_pcpu_arg(uma_zone_t zone, void *udata, int flags)
2815 {
2816 	void *item;
2817 #ifdef SMP
2818 	int i;
2819 
2820 	MPASS(zone->uz_flags & UMA_ZONE_PCPU);
2821 #endif
2822 	item = uma_zalloc_arg(zone, udata, flags & ~M_ZERO);
2823 	if (item != NULL && (flags & M_ZERO)) {
2824 #ifdef SMP
2825 		for (i = 0; i <= mp_maxid; i++)
2826 			bzero(zpcpu_get_cpu(item, i), zone->uz_size);
2827 #else
2828 		bzero(item, zone->uz_size);
2829 #endif
2830 	}
2831 	return (item);
2832 }
2833 
2834 /*
2835  * A stub while both regular and pcpu cases are identical.
2836  */
2837 void
2838 uma_zfree_pcpu_arg(uma_zone_t zone, void *item, void *udata)
2839 {
2840 
2841 #ifdef SMP
2842 	MPASS(zone->uz_flags & UMA_ZONE_PCPU);
2843 #endif
2844 	uma_zfree_arg(zone, item, udata);
2845 }
2846 
2847 #ifdef INVARIANTS
2848 #define	UMA_ALWAYS_CTORDTOR	1
2849 #else
2850 #define	UMA_ALWAYS_CTORDTOR	0
2851 #endif
2852 
2853 static void *
2854 item_ctor(uma_zone_t zone, int size, void *udata, int flags, void *item)
2855 {
2856 #ifdef INVARIANTS
2857 	bool skipdbg;
2858 
2859 	skipdbg = uma_dbg_zskip(zone, item);
2860 	if (!skipdbg && (zone->uz_flags & UMA_ZFLAG_TRASH) != 0 &&
2861 	    zone->uz_ctor != trash_ctor)
2862 		trash_ctor(item, size, udata, flags);
2863 #endif
2864 	if (__predict_false(zone->uz_ctor != NULL) &&
2865 	    zone->uz_ctor(item, size, udata, flags) != 0) {
2866 		counter_u64_add(zone->uz_fails, 1);
2867 		zone_free_item(zone, item, udata, SKIP_DTOR | SKIP_CNT);
2868 		return (NULL);
2869 	}
2870 #ifdef INVARIANTS
2871 	if (!skipdbg)
2872 		uma_dbg_alloc(zone, NULL, item);
2873 #endif
2874 	if (flags & M_ZERO)
2875 		bzero(item, size);
2876 
2877 	return (item);
2878 }
2879 
2880 static inline void
2881 item_dtor(uma_zone_t zone, void *item, int size, void *udata,
2882     enum zfreeskip skip)
2883 {
2884 #ifdef INVARIANTS
2885 	bool skipdbg;
2886 
2887 	skipdbg = uma_dbg_zskip(zone, item);
2888 	if (skip == SKIP_NONE && !skipdbg) {
2889 		if ((zone->uz_flags & UMA_ZONE_MALLOC) != 0)
2890 			uma_dbg_free(zone, udata, item);
2891 		else
2892 			uma_dbg_free(zone, NULL, item);
2893 	}
2894 #endif
2895 	if (__predict_true(skip < SKIP_DTOR)) {
2896 		if (zone->uz_dtor != NULL)
2897 			zone->uz_dtor(item, size, udata);
2898 #ifdef INVARIANTS
2899 		if (!skipdbg && (zone->uz_flags & UMA_ZFLAG_TRASH) != 0 &&
2900 		    zone->uz_dtor != trash_dtor)
2901 			trash_dtor(item, size, udata);
2902 #endif
2903 	}
2904 }
2905 
2906 /* See uma.h */
2907 void *
2908 uma_zalloc_arg(uma_zone_t zone, void *udata, int flags)
2909 {
2910 	uma_cache_bucket_t bucket;
2911 	uma_cache_t cache;
2912 	void *item;
2913 	int domain, size, uz_flags;
2914 
2915 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
2916 	random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
2917 
2918 	/* This is the fast path allocation */
2919 	CTR3(KTR_UMA, "uma_zalloc_arg zone %s(%p) flags %d", zone->uz_name,
2920 	    zone, flags);
2921 
2922 #ifdef WITNESS
2923 	if (flags & M_WAITOK) {
2924 		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
2925 		    "uma_zalloc_arg: zone \"%s\"", zone->uz_name);
2926 	}
2927 #endif
2928 
2929 #ifdef INVARIANTS
2930 	KASSERT((flags & M_EXEC) == 0, ("uma_zalloc_arg: called with M_EXEC"));
2931 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
2932 	    ("uma_zalloc_arg: called with spinlock or critical section held"));
2933 	if (zone->uz_flags & UMA_ZONE_PCPU)
2934 		KASSERT((flags & M_ZERO) == 0, ("allocating from a pcpu zone "
2935 		    "with M_ZERO passed"));
2936 #endif
2937 
2938 #ifdef DEBUG_MEMGUARD
2939 	if (memguard_cmp_zone(zone)) {
2940 		item = memguard_alloc(zone->uz_size, flags);
2941 		if (item != NULL) {
2942 			if (zone->uz_init != NULL &&
2943 			    zone->uz_init(item, zone->uz_size, flags) != 0)
2944 				return (NULL);
2945 			if (zone->uz_ctor != NULL &&
2946 			    zone->uz_ctor(item, zone->uz_size, udata,
2947 			    flags) != 0) {
2948 				counter_u64_add(zone->uz_fails, 1);
2949 			    	zone->uz_fini(item, zone->uz_size);
2950 				return (NULL);
2951 			}
2952 			return (item);
2953 		}
2954 		/* This is unfortunate but should not be fatal. */
2955 	}
2956 #endif
2957 	/*
2958 	 * If possible, allocate from the per-CPU cache.  There are two
2959 	 * requirements for safe access to the per-CPU cache: (1) the thread
2960 	 * accessing the cache must not be preempted or yield during access,
2961 	 * and (2) the thread must not migrate CPUs without switching which
2962 	 * cache it accesses.  We rely on a critical section to prevent
2963 	 * preemption and migration.  We release the critical section in
2964 	 * order to acquire the zone mutex if we are unable to allocate from
2965 	 * the current cache; when we re-acquire the critical section, we
2966 	 * must detect and handle migration if it has occurred.
2967 	 */
2968 	critical_enter();
2969 	do {
2970 		cache = &zone->uz_cpu[curcpu];
2971 		bucket = &cache->uc_allocbucket;
2972 		size = cache_uz_size(cache);
2973 		uz_flags = cache_uz_flags(cache);
2974 		if (__predict_true(bucket->ucb_cnt != 0)) {
2975 			item = cache_bucket_pop(cache, bucket);
2976 			critical_exit();
2977 			if (__predict_false((uz_flags & UMA_ZFLAG_CTORDTOR) != 0 ||
2978 			    UMA_ALWAYS_CTORDTOR))
2979 				return (item_ctor(zone, size, udata, flags, item));
2980 			if (flags & M_ZERO)
2981 				bzero(item, size);
2982 			return (item);
2983 		}
2984 	} while (cache_alloc(zone, cache, udata, flags));
2985 	critical_exit();
2986 
2987 	/*
2988 	 * We can not get a bucket so try to return a single item.
2989 	 */
2990 	if (uz_flags & UMA_ZONE_FIRSTTOUCH)
2991 		domain = PCPU_GET(domain);
2992 	else
2993 		domain = UMA_ANYDOMAIN;
2994 	return (zone_alloc_item(zone, udata, domain, flags));
2995 }
2996 
2997 /*
2998  * Replenish an alloc bucket and possibly restore an old one.  Called in
2999  * a critical section.  Returns in a critical section.
3000  *
3001  * A false return value indicates an allocation failure.
3002  * A true return value indicates success and the caller should retry.
3003  */
3004 static __noinline bool
3005 cache_alloc(uma_zone_t zone, uma_cache_t cache, void *udata, int flags)
3006 {
3007 	uma_zone_domain_t zdom;
3008 	uma_bucket_t bucket;
3009 	int domain;
3010 	bool lockfail;
3011 
3012 	CRITICAL_ASSERT(curthread);
3013 
3014 	/*
3015 	 * If we have run out of items in our alloc bucket see
3016 	 * if we can switch with the free bucket.
3017 	 */
3018 	if (cache->uc_freebucket.ucb_cnt != 0) {
3019 		cache_bucket_swap(&cache->uc_freebucket, &cache->uc_allocbucket);
3020 		return (true);
3021 	}
3022 
3023 	/*
3024 	 * Discard any empty allocation bucket while we hold no locks.
3025 	 */
3026 	bucket = cache_bucket_unload_alloc(cache);
3027 	critical_exit();
3028 	if (bucket != NULL)
3029 		bucket_free(zone, bucket, udata);
3030 
3031 	/* Short-circuit for zones without buckets and low memory. */
3032 	if (zone->uz_bucket_size == 0 || bucketdisable) {
3033 		critical_enter();
3034 		return (false);
3035 	}
3036 
3037 	/*
3038 	 * Attempt to retrieve the item from the per-CPU cache has failed, so
3039 	 * we must go back to the zone.  This requires the zone lock, so we
3040 	 * must drop the critical section, then re-acquire it when we go back
3041 	 * to the cache.  Since the critical section is released, we may be
3042 	 * preempted or migrate.  As such, make sure not to maintain any
3043 	 * thread-local state specific to the cache from prior to releasing
3044 	 * the critical section.
3045 	 */
3046 	lockfail = 0;
3047 	if (ZONE_TRYLOCK(zone) == 0) {
3048 		/* Record contention to size the buckets. */
3049 		ZONE_LOCK(zone);
3050 		lockfail = 1;
3051 	}
3052 
3053 	/* See if we lost the race to fill the cache. */
3054 	critical_enter();
3055 	cache = &zone->uz_cpu[curcpu];
3056 	if (cache->uc_allocbucket.ucb_bucket != NULL) {
3057 		ZONE_UNLOCK(zone);
3058 		return (true);
3059 	}
3060 
3061 	/*
3062 	 * Check the zone's cache of buckets.
3063 	 */
3064 	if (zone->uz_flags & UMA_ZONE_FIRSTTOUCH) {
3065 		domain = PCPU_GET(domain);
3066 		zdom = &zone->uz_domain[domain];
3067 	} else {
3068 		domain = UMA_ANYDOMAIN;
3069 		zdom = &zone->uz_domain[0];
3070 	}
3071 
3072 	if ((bucket = zone_fetch_bucket(zone, zdom)) != NULL) {
3073 		ZONE_UNLOCK(zone);
3074 		KASSERT(bucket->ub_cnt != 0,
3075 		    ("uma_zalloc_arg: Returning an empty bucket."));
3076 		cache_bucket_load_alloc(cache, bucket);
3077 		return (true);
3078 	}
3079 	/* We are no longer associated with this CPU. */
3080 	critical_exit();
3081 
3082 	/*
3083 	 * We bump the uz count when the cache size is insufficient to
3084 	 * handle the working set.
3085 	 */
3086 	if (lockfail && zone->uz_bucket_size < zone->uz_bucket_size_max)
3087 		zone->uz_bucket_size++;
3088 	ZONE_UNLOCK(zone);
3089 
3090 	/*
3091 	 * Fill a bucket and attempt to use it as the alloc bucket.
3092 	 */
3093 	bucket = zone_alloc_bucket(zone, udata, domain, flags);
3094 	CTR3(KTR_UMA, "uma_zalloc: zone %s(%p) bucket zone returned %p",
3095 	    zone->uz_name, zone, bucket);
3096 	if (bucket == NULL) {
3097 		critical_enter();
3098 		return (false);
3099 	}
3100 
3101 	/*
3102 	 * See if we lost the race or were migrated.  Cache the
3103 	 * initialized bucket to make this less likely or claim
3104 	 * the memory directly.
3105 	 */
3106 	ZONE_LOCK(zone);
3107 	critical_enter();
3108 	cache = &zone->uz_cpu[curcpu];
3109 	if (cache->uc_allocbucket.ucb_bucket == NULL &&
3110 	    ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) == 0 ||
3111 	    domain == PCPU_GET(domain))) {
3112 		cache_bucket_load_alloc(cache, bucket);
3113 		zdom->uzd_imax += bucket->ub_cnt;
3114 	} else if (zone->uz_bkt_count >= zone->uz_bkt_max) {
3115 		critical_exit();
3116 		ZONE_UNLOCK(zone);
3117 		bucket_drain(zone, bucket);
3118 		bucket_free(zone, bucket, udata);
3119 		critical_enter();
3120 		return (true);
3121 	} else
3122 		zone_put_bucket(zone, zdom, bucket, false);
3123 	ZONE_UNLOCK(zone);
3124 	return (true);
3125 }
3126 
3127 void *
3128 uma_zalloc_domain(uma_zone_t zone, void *udata, int domain, int flags)
3129 {
3130 
3131 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
3132 	random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
3133 
3134 	/* This is the fast path allocation */
3135 	CTR4(KTR_UMA, "uma_zalloc_domain zone %s(%p) domain %d flags %d",
3136 	    zone->uz_name, zone, domain, flags);
3137 
3138 	if (flags & M_WAITOK) {
3139 		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
3140 		    "uma_zalloc_domain: zone \"%s\"", zone->uz_name);
3141 	}
3142 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
3143 	    ("uma_zalloc_domain: called with spinlock or critical section held"));
3144 
3145 	return (zone_alloc_item(zone, udata, domain, flags));
3146 }
3147 
3148 /*
3149  * Find a slab with some space.  Prefer slabs that are partially used over those
3150  * that are totally full.  This helps to reduce fragmentation.
3151  *
3152  * If 'rr' is 1, search all domains starting from 'domain'.  Otherwise check
3153  * only 'domain'.
3154  */
3155 static uma_slab_t
3156 keg_first_slab(uma_keg_t keg, int domain, bool rr)
3157 {
3158 	uma_domain_t dom;
3159 	uma_slab_t slab;
3160 	int start;
3161 
3162 	KASSERT(domain >= 0 && domain < vm_ndomains,
3163 	    ("keg_first_slab: domain %d out of range", domain));
3164 	KEG_LOCK_ASSERT(keg, domain);
3165 
3166 	slab = NULL;
3167 	start = domain;
3168 	do {
3169 		dom = &keg->uk_domain[domain];
3170 		if (!LIST_EMPTY(&dom->ud_part_slab))
3171 			return (LIST_FIRST(&dom->ud_part_slab));
3172 		if (!LIST_EMPTY(&dom->ud_free_slab)) {
3173 			slab = LIST_FIRST(&dom->ud_free_slab);
3174 			LIST_REMOVE(slab, us_link);
3175 			LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
3176 			return (slab);
3177 		}
3178 		if (rr)
3179 			domain = (domain + 1) % vm_ndomains;
3180 	} while (domain != start);
3181 
3182 	return (NULL);
3183 }
3184 
3185 /*
3186  * Fetch an existing slab from a free or partial list.  Returns with the
3187  * keg domain lock held if a slab was found or unlocked if not.
3188  */
3189 static uma_slab_t
3190 keg_fetch_free_slab(uma_keg_t keg, int domain, bool rr, int flags)
3191 {
3192 	uma_slab_t slab;
3193 	uint32_t reserve;
3194 
3195 	/* HASH has a single free list. */
3196 	if ((keg->uk_flags & UMA_ZFLAG_HASH) != 0)
3197 		domain = 0;
3198 
3199 	KEG_LOCK(keg, domain);
3200 	reserve = (flags & M_USE_RESERVE) != 0 ? 0 : keg->uk_reserve;
3201 	if (keg->uk_domain[domain].ud_free <= reserve ||
3202 	    (slab = keg_first_slab(keg, domain, rr)) == NULL) {
3203 		KEG_UNLOCK(keg, domain);
3204 		return (NULL);
3205 	}
3206 	return (slab);
3207 }
3208 
3209 static uma_slab_t
3210 keg_fetch_slab(uma_keg_t keg, uma_zone_t zone, int rdomain, const int flags)
3211 {
3212 	struct vm_domainset_iter di;
3213 	uma_slab_t slab;
3214 	int aflags, domain;
3215 	bool rr;
3216 
3217 restart:
3218 	/*
3219 	 * Use the keg's policy if upper layers haven't already specified a
3220 	 * domain (as happens with first-touch zones).
3221 	 *
3222 	 * To avoid races we run the iterator with the keg lock held, but that
3223 	 * means that we cannot allow the vm_domainset layer to sleep.  Thus,
3224 	 * clear M_WAITOK and handle low memory conditions locally.
3225 	 */
3226 	rr = rdomain == UMA_ANYDOMAIN;
3227 	if (rr) {
3228 		aflags = (flags & ~M_WAITOK) | M_NOWAIT;
3229 		vm_domainset_iter_policy_ref_init(&di, &keg->uk_dr, &domain,
3230 		    &aflags);
3231 	} else {
3232 		aflags = flags;
3233 		domain = rdomain;
3234 	}
3235 
3236 	for (;;) {
3237 		slab = keg_fetch_free_slab(keg, domain, rr, flags);
3238 		if (slab != NULL)
3239 			return (slab);
3240 
3241 		/*
3242 		 * M_NOVM means don't ask at all!
3243 		 */
3244 		if (flags & M_NOVM)
3245 			break;
3246 
3247 		slab = keg_alloc_slab(keg, zone, domain, flags, aflags);
3248 		if (slab != NULL)
3249 			return (slab);
3250 		if (!rr && (flags & M_WAITOK) == 0)
3251 			break;
3252 		if (rr && vm_domainset_iter_policy(&di, &domain) != 0) {
3253 			if ((flags & M_WAITOK) != 0) {
3254 				vm_wait_doms(&keg->uk_dr.dr_policy->ds_mask);
3255 				goto restart;
3256 			}
3257 			break;
3258 		}
3259 	}
3260 
3261 	/*
3262 	 * We might not have been able to get a slab but another cpu
3263 	 * could have while we were unlocked.  Check again before we
3264 	 * fail.
3265 	 */
3266 	if ((slab = keg_fetch_free_slab(keg, domain, rr, flags)) != NULL)
3267 		return (slab);
3268 
3269 	return (NULL);
3270 }
3271 
3272 static void *
3273 slab_alloc_item(uma_keg_t keg, uma_slab_t slab)
3274 {
3275 	uma_domain_t dom;
3276 	void *item;
3277 	int freei;
3278 
3279 	KEG_LOCK_ASSERT(keg, slab->us_domain);
3280 
3281 	dom = &keg->uk_domain[slab->us_domain];
3282 	freei = BIT_FFS(keg->uk_ipers, &slab->us_free) - 1;
3283 	BIT_CLR(keg->uk_ipers, freei, &slab->us_free);
3284 	item = slab_item(slab, keg, freei);
3285 	slab->us_freecount--;
3286 	dom->ud_free--;
3287 
3288 	/* Move this slab to the full list */
3289 	if (slab->us_freecount == 0) {
3290 		LIST_REMOVE(slab, us_link);
3291 		LIST_INSERT_HEAD(&dom->ud_full_slab, slab, us_link);
3292 	}
3293 
3294 	return (item);
3295 }
3296 
3297 static int
3298 zone_import(void *arg, void **bucket, int max, int domain, int flags)
3299 {
3300 	uma_domain_t dom;
3301 	uma_zone_t zone;
3302 	uma_slab_t slab;
3303 	uma_keg_t keg;
3304 #ifdef NUMA
3305 	int stripe;
3306 #endif
3307 	int i;
3308 
3309 	zone = arg;
3310 	slab = NULL;
3311 	keg = zone->uz_keg;
3312 	/* Try to keep the buckets totally full */
3313 	for (i = 0; i < max; ) {
3314 		if ((slab = keg_fetch_slab(keg, zone, domain, flags)) == NULL)
3315 			break;
3316 #ifdef NUMA
3317 		stripe = howmany(max, vm_ndomains);
3318 #endif
3319 		dom = &keg->uk_domain[slab->us_domain];
3320 		while (slab->us_freecount && i < max) {
3321 			bucket[i++] = slab_alloc_item(keg, slab);
3322 			if (dom->ud_free <= keg->uk_reserve)
3323 				break;
3324 #ifdef NUMA
3325 			/*
3326 			 * If the zone is striped we pick a new slab for every
3327 			 * N allocations.  Eliminating this conditional will
3328 			 * instead pick a new domain for each bucket rather
3329 			 * than stripe within each bucket.  The current option
3330 			 * produces more fragmentation and requires more cpu
3331 			 * time but yields better distribution.
3332 			 */
3333 			if ((zone->uz_flags & UMA_ZONE_ROUNDROBIN) != 0 &&
3334 			    vm_ndomains > 1 && --stripe == 0)
3335 				break;
3336 #endif
3337 		}
3338 		KEG_UNLOCK(keg, slab->us_domain);
3339 		/* Don't block if we allocated any successfully. */
3340 		flags &= ~M_WAITOK;
3341 		flags |= M_NOWAIT;
3342 	}
3343 
3344 	return i;
3345 }
3346 
3347 static int
3348 zone_alloc_limit_hard(uma_zone_t zone, int count, int flags)
3349 {
3350 	uint64_t old, new, total, max;
3351 
3352 	/*
3353 	 * The hard case.  We're going to sleep because there were existing
3354 	 * sleepers or because we ran out of items.  This routine enforces
3355 	 * fairness by keeping fifo order.
3356 	 *
3357 	 * First release our ill gotten gains and make some noise.
3358 	 */
3359 	for (;;) {
3360 		zone_free_limit(zone, count);
3361 		zone_log_warning(zone);
3362 		zone_maxaction(zone);
3363 		if (flags & M_NOWAIT)
3364 			return (0);
3365 
3366 		/*
3367 		 * We need to allocate an item or set ourself as a sleeper
3368 		 * while the sleepq lock is held to avoid wakeup races.  This
3369 		 * is essentially a home rolled semaphore.
3370 		 */
3371 		sleepq_lock(&zone->uz_max_items);
3372 		old = zone->uz_items;
3373 		do {
3374 			MPASS(UZ_ITEMS_SLEEPERS(old) < UZ_ITEMS_SLEEPERS_MAX);
3375 			/* Cache the max since we will evaluate twice. */
3376 			max = zone->uz_max_items;
3377 			if (UZ_ITEMS_SLEEPERS(old) != 0 ||
3378 			    UZ_ITEMS_COUNT(old) >= max)
3379 				new = old + UZ_ITEMS_SLEEPER;
3380 			else
3381 				new = old + MIN(count, max - old);
3382 		} while (atomic_fcmpset_64(&zone->uz_items, &old, new) == 0);
3383 
3384 		/* We may have successfully allocated under the sleepq lock. */
3385 		if (UZ_ITEMS_SLEEPERS(new) == 0) {
3386 			sleepq_release(&zone->uz_max_items);
3387 			return (new - old);
3388 		}
3389 
3390 		/*
3391 		 * This is in a different cacheline from uz_items so that we
3392 		 * don't constantly invalidate the fastpath cacheline when we
3393 		 * adjust item counts.  This could be limited to toggling on
3394 		 * transitions.
3395 		 */
3396 		atomic_add_32(&zone->uz_sleepers, 1);
3397 		atomic_add_64(&zone->uz_sleeps, 1);
3398 
3399 		/*
3400 		 * We have added ourselves as a sleeper.  The sleepq lock
3401 		 * protects us from wakeup races.  Sleep now and then retry.
3402 		 */
3403 		sleepq_add(&zone->uz_max_items, NULL, "zonelimit", 0, 0);
3404 		sleepq_wait(&zone->uz_max_items, PVM);
3405 
3406 		/*
3407 		 * After wakeup, remove ourselves as a sleeper and try
3408 		 * again.  We no longer have the sleepq lock for protection.
3409 		 *
3410 		 * Subract ourselves as a sleeper while attempting to add
3411 		 * our count.
3412 		 */
3413 		atomic_subtract_32(&zone->uz_sleepers, 1);
3414 		old = atomic_fetchadd_64(&zone->uz_items,
3415 		    -(UZ_ITEMS_SLEEPER - count));
3416 		/* We're no longer a sleeper. */
3417 		old -= UZ_ITEMS_SLEEPER;
3418 
3419 		/*
3420 		 * If we're still at the limit, restart.  Notably do not
3421 		 * block on other sleepers.  Cache the max value to protect
3422 		 * against changes via sysctl.
3423 		 */
3424 		total = UZ_ITEMS_COUNT(old);
3425 		max = zone->uz_max_items;
3426 		if (total >= max)
3427 			continue;
3428 		/* Truncate if necessary, otherwise wake other sleepers. */
3429 		if (total + count > max) {
3430 			zone_free_limit(zone, total + count - max);
3431 			count = max - total;
3432 		} else if (total + count < max && UZ_ITEMS_SLEEPERS(old) != 0)
3433 			wakeup_one(&zone->uz_max_items);
3434 
3435 		return (count);
3436 	}
3437 }
3438 
3439 /*
3440  * Allocate 'count' items from our max_items limit.  Returns the number
3441  * available.  If M_NOWAIT is not specified it will sleep until at least
3442  * one item can be allocated.
3443  */
3444 static int
3445 zone_alloc_limit(uma_zone_t zone, int count, int flags)
3446 {
3447 	uint64_t old;
3448 	uint64_t max;
3449 
3450 	max = zone->uz_max_items;
3451 	MPASS(max > 0);
3452 
3453 	/*
3454 	 * We expect normal allocations to succeed with a simple
3455 	 * fetchadd.
3456 	 */
3457 	old = atomic_fetchadd_64(&zone->uz_items, count);
3458 	if (__predict_true(old + count <= max))
3459 		return (count);
3460 
3461 	/*
3462 	 * If we had some items and no sleepers just return the
3463 	 * truncated value.  We have to release the excess space
3464 	 * though because that may wake sleepers who weren't woken
3465 	 * because we were temporarily over the limit.
3466 	 */
3467 	if (old < max) {
3468 		zone_free_limit(zone, (old + count) - max);
3469 		return (max - old);
3470 	}
3471 	return (zone_alloc_limit_hard(zone, count, flags));
3472 }
3473 
3474 /*
3475  * Free a number of items back to the limit.
3476  */
3477 static void
3478 zone_free_limit(uma_zone_t zone, int count)
3479 {
3480 	uint64_t old;
3481 
3482 	MPASS(count > 0);
3483 
3484 	/*
3485 	 * In the common case we either have no sleepers or
3486 	 * are still over the limit and can just return.
3487 	 */
3488 	old = atomic_fetchadd_64(&zone->uz_items, -count);
3489 	if (__predict_true(UZ_ITEMS_SLEEPERS(old) == 0 ||
3490 	   UZ_ITEMS_COUNT(old) - count >= zone->uz_max_items))
3491 		return;
3492 
3493 	/*
3494 	 * Moderate the rate of wakeups.  Sleepers will continue
3495 	 * to generate wakeups if necessary.
3496 	 */
3497 	wakeup_one(&zone->uz_max_items);
3498 }
3499 
3500 static uma_bucket_t
3501 zone_alloc_bucket(uma_zone_t zone, void *udata, int domain, int flags)
3502 {
3503 	uma_bucket_t bucket;
3504 	int maxbucket, cnt;
3505 
3506 	CTR3(KTR_UMA, "zone_alloc_bucket zone %s(%p) domain %d", zone->uz_name,
3507 	    zone, domain);
3508 
3509 	/* Avoid allocs targeting empty domains. */
3510 	if (domain != UMA_ANYDOMAIN && VM_DOMAIN_EMPTY(domain))
3511 		domain = UMA_ANYDOMAIN;
3512 
3513 	if (zone->uz_max_items > 0)
3514 		maxbucket = zone_alloc_limit(zone, zone->uz_bucket_size,
3515 		    M_NOWAIT);
3516 	else
3517 		maxbucket = zone->uz_bucket_size;
3518 	if (maxbucket == 0)
3519 		return (false);
3520 
3521 	/* Don't wait for buckets, preserve caller's NOVM setting. */
3522 	bucket = bucket_alloc(zone, udata, M_NOWAIT | (flags & M_NOVM));
3523 	if (bucket == NULL) {
3524 		cnt = 0;
3525 		goto out;
3526 	}
3527 
3528 	bucket->ub_cnt = zone->uz_import(zone->uz_arg, bucket->ub_bucket,
3529 	    MIN(maxbucket, bucket->ub_entries), domain, flags);
3530 
3531 	/*
3532 	 * Initialize the memory if necessary.
3533 	 */
3534 	if (bucket->ub_cnt != 0 && zone->uz_init != NULL) {
3535 		int i;
3536 
3537 		for (i = 0; i < bucket->ub_cnt; i++)
3538 			if (zone->uz_init(bucket->ub_bucket[i], zone->uz_size,
3539 			    flags) != 0)
3540 				break;
3541 		/*
3542 		 * If we couldn't initialize the whole bucket, put the
3543 		 * rest back onto the freelist.
3544 		 */
3545 		if (i != bucket->ub_cnt) {
3546 			zone->uz_release(zone->uz_arg, &bucket->ub_bucket[i],
3547 			    bucket->ub_cnt - i);
3548 #ifdef INVARIANTS
3549 			bzero(&bucket->ub_bucket[i],
3550 			    sizeof(void *) * (bucket->ub_cnt - i));
3551 #endif
3552 			bucket->ub_cnt = i;
3553 		}
3554 	}
3555 
3556 	cnt = bucket->ub_cnt;
3557 	if (bucket->ub_cnt == 0) {
3558 		bucket_free(zone, bucket, udata);
3559 		counter_u64_add(zone->uz_fails, 1);
3560 		bucket = NULL;
3561 	}
3562 out:
3563 	if (zone->uz_max_items > 0 && cnt < maxbucket)
3564 		zone_free_limit(zone, maxbucket - cnt);
3565 
3566 	return (bucket);
3567 }
3568 
3569 /*
3570  * Allocates a single item from a zone.
3571  *
3572  * Arguments
3573  *	zone   The zone to alloc for.
3574  *	udata  The data to be passed to the constructor.
3575  *	domain The domain to allocate from or UMA_ANYDOMAIN.
3576  *	flags  M_WAITOK, M_NOWAIT, M_ZERO.
3577  *
3578  * Returns
3579  *	NULL if there is no memory and M_NOWAIT is set
3580  *	An item if successful
3581  */
3582 
3583 static void *
3584 zone_alloc_item(uma_zone_t zone, void *udata, int domain, int flags)
3585 {
3586 	void *item;
3587 
3588 	if (zone->uz_max_items > 0 && zone_alloc_limit(zone, 1, flags) == 0)
3589 		return (NULL);
3590 
3591 	/* Avoid allocs targeting empty domains. */
3592 	if (domain != UMA_ANYDOMAIN && VM_DOMAIN_EMPTY(domain))
3593 		domain = UMA_ANYDOMAIN;
3594 
3595 	if (zone->uz_import(zone->uz_arg, &item, 1, domain, flags) != 1)
3596 		goto fail_cnt;
3597 
3598 	/*
3599 	 * We have to call both the zone's init (not the keg's init)
3600 	 * and the zone's ctor.  This is because the item is going from
3601 	 * a keg slab directly to the user, and the user is expecting it
3602 	 * to be both zone-init'd as well as zone-ctor'd.
3603 	 */
3604 	if (zone->uz_init != NULL) {
3605 		if (zone->uz_init(item, zone->uz_size, flags) != 0) {
3606 			zone_free_item(zone, item, udata, SKIP_FINI | SKIP_CNT);
3607 			goto fail_cnt;
3608 		}
3609 	}
3610 	item = item_ctor(zone, zone->uz_size, udata, flags, item);
3611 	if (item == NULL)
3612 		goto fail;
3613 
3614 	counter_u64_add(zone->uz_allocs, 1);
3615 	CTR3(KTR_UMA, "zone_alloc_item item %p from %s(%p)", item,
3616 	    zone->uz_name, zone);
3617 
3618 	return (item);
3619 
3620 fail_cnt:
3621 	counter_u64_add(zone->uz_fails, 1);
3622 fail:
3623 	if (zone->uz_max_items > 0)
3624 		zone_free_limit(zone, 1);
3625 	CTR2(KTR_UMA, "zone_alloc_item failed from %s(%p)",
3626 	    zone->uz_name, zone);
3627 
3628 	return (NULL);
3629 }
3630 
3631 /* See uma.h */
3632 void
3633 uma_zfree_arg(uma_zone_t zone, void *item, void *udata)
3634 {
3635 	uma_cache_t cache;
3636 	uma_cache_bucket_t bucket;
3637 	int domain, itemdomain, uz_flags;
3638 
3639 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
3640 	random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
3641 
3642 	CTR2(KTR_UMA, "uma_zfree_arg zone %s(%p)", zone->uz_name, zone);
3643 
3644 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
3645 	    ("uma_zfree_arg: called with spinlock or critical section held"));
3646 
3647         /* uma_zfree(..., NULL) does nothing, to match free(9). */
3648         if (item == NULL)
3649                 return;
3650 #ifdef DEBUG_MEMGUARD
3651 	if (is_memguard_addr(item)) {
3652 		if (zone->uz_dtor != NULL)
3653 			zone->uz_dtor(item, zone->uz_size, udata);
3654 		if (zone->uz_fini != NULL)
3655 			zone->uz_fini(item, zone->uz_size);
3656 		memguard_free(item);
3657 		return;
3658 	}
3659 #endif
3660 
3661 	/*
3662 	 * We are accessing the per-cpu cache without a critical section to
3663 	 * fetch size and flags.  This is acceptable, if we are preempted we
3664 	 * will simply read another cpu's line.
3665 	 */
3666 	cache = &zone->uz_cpu[curcpu];
3667 	uz_flags = cache_uz_flags(cache);
3668 	if (__predict_false((uz_flags & UMA_ZFLAG_CTORDTOR) != 0 ||
3669 	    UMA_ALWAYS_CTORDTOR))
3670 		item_dtor(zone, item, cache_uz_size(cache), udata, SKIP_NONE);
3671 
3672 	/*
3673 	 * The race here is acceptable.  If we miss it we'll just have to wait
3674 	 * a little longer for the limits to be reset.
3675 	 */
3676 	if (__predict_false(uz_flags & UMA_ZFLAG_LIMIT)) {
3677 		if (zone->uz_sleepers > 0)
3678 			goto zfree_item;
3679 	}
3680 
3681 	/*
3682 	 * If possible, free to the per-CPU cache.  There are two
3683 	 * requirements for safe access to the per-CPU cache: (1) the thread
3684 	 * accessing the cache must not be preempted or yield during access,
3685 	 * and (2) the thread must not migrate CPUs without switching which
3686 	 * cache it accesses.  We rely on a critical section to prevent
3687 	 * preemption and migration.  We release the critical section in
3688 	 * order to acquire the zone mutex if we are unable to free to the
3689 	 * current cache; when we re-acquire the critical section, we must
3690 	 * detect and handle migration if it has occurred.
3691 	 */
3692 	domain = itemdomain = 0;
3693 #ifdef NUMA
3694 	if ((uz_flags & UMA_ZONE_FIRSTTOUCH) != 0)
3695 		itemdomain = _vm_phys_domain(pmap_kextract((vm_offset_t)item));
3696 #endif
3697 	critical_enter();
3698 	do {
3699 		cache = &zone->uz_cpu[curcpu];
3700 #ifdef NUMA
3701 		domain = PCPU_GET(domain);
3702 		if ((uz_flags & UMA_ZONE_FIRSTTOUCH) != 0 &&
3703 		    domain != itemdomain) {
3704 			bucket = &cache->uc_crossbucket;
3705 		} else
3706 #endif
3707 		{
3708 			/*
3709 			 * Try to free into the allocbucket first to give LIFO
3710 			 * ordering for cache-hot datastructures.  Spill over
3711 			 * into the freebucket if necessary.  Alloc will swap
3712 			 * them if one runs dry.
3713 			 */
3714 			bucket = &cache->uc_allocbucket;
3715 			if (__predict_false(bucket->ucb_cnt >=
3716 			    bucket->ucb_entries))
3717 				bucket = &cache->uc_freebucket;
3718 		}
3719 		if (__predict_true(bucket->ucb_cnt < bucket->ucb_entries)) {
3720 			cache_bucket_push(cache, bucket, item);
3721 			critical_exit();
3722 			return;
3723 		}
3724 	} while (cache_free(zone, cache, udata, item, itemdomain));
3725 	critical_exit();
3726 
3727 	/*
3728 	 * If nothing else caught this, we'll just do an internal free.
3729 	 */
3730 zfree_item:
3731 	zone_free_item(zone, item, udata, SKIP_DTOR);
3732 }
3733 
3734 #ifdef NUMA
3735 /*
3736  * sort crossdomain free buckets to domain correct buckets and cache
3737  * them.
3738  */
3739 static void
3740 zone_free_cross(uma_zone_t zone, uma_bucket_t bucket, void *udata)
3741 {
3742 	struct uma_bucketlist fullbuckets;
3743 	uma_zone_domain_t zdom;
3744 	uma_bucket_t b;
3745 	void *item;
3746 	int domain;
3747 
3748 	CTR3(KTR_UMA,
3749 	    "uma_zfree: zone %s(%p) draining cross bucket %p",
3750 	    zone->uz_name, zone, bucket);
3751 
3752 	TAILQ_INIT(&fullbuckets);
3753 
3754 	/*
3755 	 * To avoid having ndomain * ndomain buckets for sorting we have a
3756 	 * lock on the current crossfree bucket.  A full matrix with
3757 	 * per-domain locking could be used if necessary.
3758 	 */
3759 	ZONE_CROSS_LOCK(zone);
3760 	while (bucket->ub_cnt > 0) {
3761 		item = bucket->ub_bucket[bucket->ub_cnt - 1];
3762 		domain = _vm_phys_domain(pmap_kextract((vm_offset_t)item));
3763 		zdom = &zone->uz_domain[domain];
3764 		if (zdom->uzd_cross == NULL) {
3765 			zdom->uzd_cross = bucket_alloc(zone, udata, M_NOWAIT);
3766 			if (zdom->uzd_cross == NULL)
3767 				break;
3768 		}
3769 		zdom->uzd_cross->ub_bucket[zdom->uzd_cross->ub_cnt++] = item;
3770 		if (zdom->uzd_cross->ub_cnt == zdom->uzd_cross->ub_entries) {
3771 			TAILQ_INSERT_HEAD(&fullbuckets, zdom->uzd_cross,
3772 			    ub_link);
3773 			zdom->uzd_cross = NULL;
3774 		}
3775 		bucket->ub_cnt--;
3776 	}
3777 	ZONE_CROSS_UNLOCK(zone);
3778 	if (!TAILQ_EMPTY(&fullbuckets)) {
3779 		ZONE_LOCK(zone);
3780 		while ((b = TAILQ_FIRST(&fullbuckets)) != NULL) {
3781 			TAILQ_REMOVE(&fullbuckets, b, ub_link);
3782 			if (zone->uz_bkt_count >= zone->uz_bkt_max) {
3783 				ZONE_UNLOCK(zone);
3784 				bucket_drain(zone, b);
3785 				bucket_free(zone, b, udata);
3786 				ZONE_LOCK(zone);
3787 			} else {
3788 				domain = _vm_phys_domain(
3789 				    pmap_kextract(
3790 				    (vm_offset_t)b->ub_bucket[0]));
3791 				zdom = &zone->uz_domain[domain];
3792 				zone_put_bucket(zone, zdom, b, true);
3793 			}
3794 		}
3795 		ZONE_UNLOCK(zone);
3796 	}
3797 	if (bucket->ub_cnt != 0)
3798 		bucket_drain(zone, bucket);
3799 	bucket_free(zone, bucket, udata);
3800 }
3801 #endif
3802 
3803 static void
3804 zone_free_bucket(uma_zone_t zone, uma_bucket_t bucket, void *udata,
3805     int domain, int itemdomain)
3806 {
3807 	uma_zone_domain_t zdom;
3808 
3809 #ifdef NUMA
3810 	/*
3811 	 * Buckets coming from the wrong domain will be entirely for the
3812 	 * only other domain on two domain systems.  In this case we can
3813 	 * simply cache them.  Otherwise we need to sort them back to
3814 	 * correct domains.
3815 	 */
3816 	if (domain != itemdomain && vm_ndomains > 2) {
3817 		zone_free_cross(zone, bucket, udata);
3818 		return;
3819 	}
3820 #endif
3821 
3822 	/*
3823 	 * Attempt to save the bucket in the zone's domain bucket cache.
3824 	 *
3825 	 * We bump the uz count when the cache size is insufficient to
3826 	 * handle the working set.
3827 	 */
3828 	if (ZONE_TRYLOCK(zone) == 0) {
3829 		/* Record contention to size the buckets. */
3830 		ZONE_LOCK(zone);
3831 		if (zone->uz_bucket_size < zone->uz_bucket_size_max)
3832 			zone->uz_bucket_size++;
3833 	}
3834 
3835 	CTR3(KTR_UMA,
3836 	    "uma_zfree: zone %s(%p) putting bucket %p on free list",
3837 	    zone->uz_name, zone, bucket);
3838 	/* ub_cnt is pointing to the last free item */
3839 	KASSERT(bucket->ub_cnt == bucket->ub_entries,
3840 	    ("uma_zfree: Attempting to insert partial  bucket onto the full list.\n"));
3841 	if (zone->uz_bkt_count >= zone->uz_bkt_max) {
3842 		ZONE_UNLOCK(zone);
3843 		bucket_drain(zone, bucket);
3844 		bucket_free(zone, bucket, udata);
3845 	} else {
3846 		zdom = &zone->uz_domain[itemdomain];
3847 		zone_put_bucket(zone, zdom, bucket, true);
3848 		ZONE_UNLOCK(zone);
3849 	}
3850 }
3851 
3852 /*
3853  * Populate a free or cross bucket for the current cpu cache.  Free any
3854  * existing full bucket either to the zone cache or back to the slab layer.
3855  *
3856  * Enters and returns in a critical section.  false return indicates that
3857  * we can not satisfy this free in the cache layer.  true indicates that
3858  * the caller should retry.
3859  */
3860 static __noinline bool
3861 cache_free(uma_zone_t zone, uma_cache_t cache, void *udata, void *item,
3862     int itemdomain)
3863 {
3864 	uma_cache_bucket_t cbucket;
3865 	uma_bucket_t bucket;
3866 	int domain;
3867 
3868 	CRITICAL_ASSERT(curthread);
3869 
3870 	if (zone->uz_bucket_size == 0 || bucketdisable)
3871 		return false;
3872 
3873 	cache = &zone->uz_cpu[curcpu];
3874 
3875 	/*
3876 	 * FIRSTTOUCH domains need to free to the correct zdom.  When
3877 	 * enabled this is the zdom of the item.   The bucket is the
3878 	 * cross bucket if the current domain and itemdomain do not match.
3879 	 */
3880 	cbucket = &cache->uc_freebucket;
3881 #ifdef NUMA
3882 	if ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) != 0) {
3883 		domain = PCPU_GET(domain);
3884 		if (domain != itemdomain) {
3885 			cbucket = &cache->uc_crossbucket;
3886 			if (cbucket->ucb_cnt != 0)
3887 				atomic_add_64(&zone->uz_xdomain,
3888 				    cbucket->ucb_cnt);
3889 		}
3890 	} else
3891 #endif
3892 		itemdomain = domain = 0;
3893 	bucket = cache_bucket_unload(cbucket);
3894 
3895 	/* We are no longer associated with this CPU. */
3896 	critical_exit();
3897 
3898 	if (bucket != NULL)
3899 		zone_free_bucket(zone, bucket, udata, domain, itemdomain);
3900 
3901 	bucket = bucket_alloc(zone, udata, M_NOWAIT);
3902 	CTR3(KTR_UMA, "uma_zfree: zone %s(%p) allocated bucket %p",
3903 	    zone->uz_name, zone, bucket);
3904 	critical_enter();
3905 	if (bucket == NULL)
3906 		return (false);
3907 	cache = &zone->uz_cpu[curcpu];
3908 #ifdef NUMA
3909 	/*
3910 	 * Check to see if we should be populating the cross bucket.  If it
3911 	 * is already populated we will fall through and attempt to populate
3912 	 * the free bucket.
3913 	 */
3914 	if ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) != 0) {
3915 		domain = PCPU_GET(domain);
3916 		if (domain != itemdomain &&
3917 		    cache->uc_crossbucket.ucb_bucket == NULL) {
3918 			cache_bucket_load_cross(cache, bucket);
3919 			return (true);
3920 		}
3921 	}
3922 #endif
3923 	/*
3924 	 * We may have lost the race to fill the bucket or switched CPUs.
3925 	 */
3926 	if (cache->uc_freebucket.ucb_bucket != NULL) {
3927 		critical_exit();
3928 		bucket_free(zone, bucket, udata);
3929 		critical_enter();
3930 	} else
3931 		cache_bucket_load_free(cache, bucket);
3932 
3933 	return (true);
3934 }
3935 
3936 void
3937 uma_zfree_domain(uma_zone_t zone, void *item, void *udata)
3938 {
3939 
3940 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
3941 	random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
3942 
3943 	CTR2(KTR_UMA, "uma_zfree_domain zone %s(%p)", zone->uz_name, zone);
3944 
3945 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
3946 	    ("uma_zfree_domain: called with spinlock or critical section held"));
3947 
3948         /* uma_zfree(..., NULL) does nothing, to match free(9). */
3949         if (item == NULL)
3950                 return;
3951 	zone_free_item(zone, item, udata, SKIP_NONE);
3952 }
3953 
3954 static void
3955 slab_free_item(uma_zone_t zone, uma_slab_t slab, void *item)
3956 {
3957 	uma_keg_t keg;
3958 	uma_domain_t dom;
3959 	int freei;
3960 
3961 	keg = zone->uz_keg;
3962 	KEG_LOCK_ASSERT(keg, slab->us_domain);
3963 
3964 	/* Do we need to remove from any lists? */
3965 	dom = &keg->uk_domain[slab->us_domain];
3966 	if (slab->us_freecount+1 == keg->uk_ipers) {
3967 		LIST_REMOVE(slab, us_link);
3968 		LIST_INSERT_HEAD(&dom->ud_free_slab, slab, us_link);
3969 	} else if (slab->us_freecount == 0) {
3970 		LIST_REMOVE(slab, us_link);
3971 		LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
3972 	}
3973 
3974 	/* Slab management. */
3975 	freei = slab_item_index(slab, keg, item);
3976 	BIT_SET(keg->uk_ipers, freei, &slab->us_free);
3977 	slab->us_freecount++;
3978 
3979 	/* Keg statistics. */
3980 	dom->ud_free++;
3981 }
3982 
3983 static void
3984 zone_release(void *arg, void **bucket, int cnt)
3985 {
3986 	struct mtx *lock;
3987 	uma_zone_t zone;
3988 	uma_slab_t slab;
3989 	uma_keg_t keg;
3990 	uint8_t *mem;
3991 	void *item;
3992 	int i;
3993 
3994 	zone = arg;
3995 	keg = zone->uz_keg;
3996 	lock = NULL;
3997 	if (__predict_false((zone->uz_flags & UMA_ZFLAG_HASH) != 0))
3998 		lock = KEG_LOCK(keg, 0);
3999 	for (i = 0; i < cnt; i++) {
4000 		item = bucket[i];
4001 		if (__predict_true((zone->uz_flags & UMA_ZFLAG_VTOSLAB) != 0)) {
4002 			slab = vtoslab((vm_offset_t)item);
4003 		} else {
4004 			mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
4005 			if ((zone->uz_flags & UMA_ZFLAG_HASH) != 0)
4006 				slab = hash_sfind(&keg->uk_hash, mem);
4007 			else
4008 				slab = (uma_slab_t)(mem + keg->uk_pgoff);
4009 		}
4010 		if (lock != KEG_LOCKPTR(keg, slab->us_domain)) {
4011 			if (lock != NULL)
4012 				mtx_unlock(lock);
4013 			lock = KEG_LOCK(keg, slab->us_domain);
4014 		}
4015 		slab_free_item(zone, slab, item);
4016 	}
4017 	if (lock != NULL)
4018 		mtx_unlock(lock);
4019 }
4020 
4021 /*
4022  * Frees a single item to any zone.
4023  *
4024  * Arguments:
4025  *	zone   The zone to free to
4026  *	item   The item we're freeing
4027  *	udata  User supplied data for the dtor
4028  *	skip   Skip dtors and finis
4029  */
4030 static void
4031 zone_free_item(uma_zone_t zone, void *item, void *udata, enum zfreeskip skip)
4032 {
4033 
4034 	item_dtor(zone, item, zone->uz_size, udata, skip);
4035 
4036 	if (skip < SKIP_FINI && zone->uz_fini)
4037 		zone->uz_fini(item, zone->uz_size);
4038 
4039 	zone->uz_release(zone->uz_arg, &item, 1);
4040 
4041 	if (skip & SKIP_CNT)
4042 		return;
4043 
4044 	counter_u64_add(zone->uz_frees, 1);
4045 
4046 	if (zone->uz_max_items > 0)
4047 		zone_free_limit(zone, 1);
4048 }
4049 
4050 /* See uma.h */
4051 int
4052 uma_zone_set_max(uma_zone_t zone, int nitems)
4053 {
4054 	struct uma_bucket_zone *ubz;
4055 	int count;
4056 
4057 	/*
4058 	 * XXX This can misbehave if the zone has any allocations with
4059 	 * no limit and a limit is imposed.  There is currently no
4060 	 * way to clear a limit.
4061 	 */
4062 	ZONE_LOCK(zone);
4063 	ubz = bucket_zone_max(zone, nitems);
4064 	count = ubz != NULL ? ubz->ubz_entries : 0;
4065 	zone->uz_bucket_size_max = zone->uz_bucket_size = count;
4066 	if (zone->uz_bucket_size_min > zone->uz_bucket_size_max)
4067 		zone->uz_bucket_size_min = zone->uz_bucket_size_max;
4068 	zone->uz_max_items = nitems;
4069 	zone->uz_flags |= UMA_ZFLAG_LIMIT;
4070 	zone_update_caches(zone);
4071 	/* We may need to wake waiters. */
4072 	wakeup(&zone->uz_max_items);
4073 	ZONE_UNLOCK(zone);
4074 
4075 	return (nitems);
4076 }
4077 
4078 /* See uma.h */
4079 void
4080 uma_zone_set_maxcache(uma_zone_t zone, int nitems)
4081 {
4082 	struct uma_bucket_zone *ubz;
4083 	int bpcpu;
4084 
4085 	ZONE_LOCK(zone);
4086 	ubz = bucket_zone_max(zone, nitems);
4087 	if (ubz != NULL) {
4088 		bpcpu = 2;
4089 		if ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) != 0)
4090 			/* Count the cross-domain bucket. */
4091 			bpcpu++;
4092 		nitems -= ubz->ubz_entries * bpcpu * mp_ncpus;
4093 		zone->uz_bucket_size_max = ubz->ubz_entries;
4094 	} else {
4095 		zone->uz_bucket_size_max = zone->uz_bucket_size = 0;
4096 	}
4097 	if (zone->uz_bucket_size_min > zone->uz_bucket_size_max)
4098 		zone->uz_bucket_size_min = zone->uz_bucket_size_max;
4099 	zone->uz_bkt_max = nitems;
4100 	ZONE_UNLOCK(zone);
4101 }
4102 
4103 /* See uma.h */
4104 int
4105 uma_zone_get_max(uma_zone_t zone)
4106 {
4107 	int nitems;
4108 
4109 	nitems = atomic_load_64(&zone->uz_max_items);
4110 
4111 	return (nitems);
4112 }
4113 
4114 /* See uma.h */
4115 void
4116 uma_zone_set_warning(uma_zone_t zone, const char *warning)
4117 {
4118 
4119 	ZONE_ASSERT_COLD(zone);
4120 	zone->uz_warning = warning;
4121 }
4122 
4123 /* See uma.h */
4124 void
4125 uma_zone_set_maxaction(uma_zone_t zone, uma_maxaction_t maxaction)
4126 {
4127 
4128 	ZONE_ASSERT_COLD(zone);
4129 	TASK_INIT(&zone->uz_maxaction, 0, (task_fn_t *)maxaction, zone);
4130 }
4131 
4132 /* See uma.h */
4133 int
4134 uma_zone_get_cur(uma_zone_t zone)
4135 {
4136 	int64_t nitems;
4137 	u_int i;
4138 
4139 	nitems = 0;
4140 	if (zone->uz_allocs != EARLY_COUNTER && zone->uz_frees != EARLY_COUNTER)
4141 		nitems = counter_u64_fetch(zone->uz_allocs) -
4142 		    counter_u64_fetch(zone->uz_frees);
4143 	CPU_FOREACH(i)
4144 		nitems += atomic_load_64(&zone->uz_cpu[i].uc_allocs) -
4145 		    atomic_load_64(&zone->uz_cpu[i].uc_frees);
4146 
4147 	return (nitems < 0 ? 0 : nitems);
4148 }
4149 
4150 static uint64_t
4151 uma_zone_get_allocs(uma_zone_t zone)
4152 {
4153 	uint64_t nitems;
4154 	u_int i;
4155 
4156 	nitems = 0;
4157 	if (zone->uz_allocs != EARLY_COUNTER)
4158 		nitems = counter_u64_fetch(zone->uz_allocs);
4159 	CPU_FOREACH(i)
4160 		nitems += atomic_load_64(&zone->uz_cpu[i].uc_allocs);
4161 
4162 	return (nitems);
4163 }
4164 
4165 static uint64_t
4166 uma_zone_get_frees(uma_zone_t zone)
4167 {
4168 	uint64_t nitems;
4169 	u_int i;
4170 
4171 	nitems = 0;
4172 	if (zone->uz_frees != EARLY_COUNTER)
4173 		nitems = counter_u64_fetch(zone->uz_frees);
4174 	CPU_FOREACH(i)
4175 		nitems += atomic_load_64(&zone->uz_cpu[i].uc_frees);
4176 
4177 	return (nitems);
4178 }
4179 
4180 #ifdef INVARIANTS
4181 /* Used only for KEG_ASSERT_COLD(). */
4182 static uint64_t
4183 uma_keg_get_allocs(uma_keg_t keg)
4184 {
4185 	uma_zone_t z;
4186 	uint64_t nitems;
4187 
4188 	nitems = 0;
4189 	LIST_FOREACH(z, &keg->uk_zones, uz_link)
4190 		nitems += uma_zone_get_allocs(z);
4191 
4192 	return (nitems);
4193 }
4194 #endif
4195 
4196 /* See uma.h */
4197 void
4198 uma_zone_set_init(uma_zone_t zone, uma_init uminit)
4199 {
4200 	uma_keg_t keg;
4201 
4202 	KEG_GET(zone, keg);
4203 	KEG_ASSERT_COLD(keg);
4204 	keg->uk_init = uminit;
4205 }
4206 
4207 /* See uma.h */
4208 void
4209 uma_zone_set_fini(uma_zone_t zone, uma_fini fini)
4210 {
4211 	uma_keg_t keg;
4212 
4213 	KEG_GET(zone, keg);
4214 	KEG_ASSERT_COLD(keg);
4215 	keg->uk_fini = fini;
4216 }
4217 
4218 /* See uma.h */
4219 void
4220 uma_zone_set_zinit(uma_zone_t zone, uma_init zinit)
4221 {
4222 
4223 	ZONE_ASSERT_COLD(zone);
4224 	zone->uz_init = zinit;
4225 }
4226 
4227 /* See uma.h */
4228 void
4229 uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini)
4230 {
4231 
4232 	ZONE_ASSERT_COLD(zone);
4233 	zone->uz_fini = zfini;
4234 }
4235 
4236 /* See uma.h */
4237 void
4238 uma_zone_set_freef(uma_zone_t zone, uma_free freef)
4239 {
4240 	uma_keg_t keg;
4241 
4242 	KEG_GET(zone, keg);
4243 	KEG_ASSERT_COLD(keg);
4244 	keg->uk_freef = freef;
4245 }
4246 
4247 /* See uma.h */
4248 void
4249 uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf)
4250 {
4251 	uma_keg_t keg;
4252 
4253 	KEG_GET(zone, keg);
4254 	KEG_ASSERT_COLD(keg);
4255 	keg->uk_allocf = allocf;
4256 }
4257 
4258 /* See uma.h */
4259 void
4260 uma_zone_reserve(uma_zone_t zone, int items)
4261 {
4262 	uma_keg_t keg;
4263 
4264 	KEG_GET(zone, keg);
4265 	KEG_ASSERT_COLD(keg);
4266 	keg->uk_reserve = items;
4267 }
4268 
4269 /* See uma.h */
4270 int
4271 uma_zone_reserve_kva(uma_zone_t zone, int count)
4272 {
4273 	uma_keg_t keg;
4274 	vm_offset_t kva;
4275 	u_int pages;
4276 
4277 	KEG_GET(zone, keg);
4278 	KEG_ASSERT_COLD(keg);
4279 	ZONE_ASSERT_COLD(zone);
4280 
4281 	pages = howmany(count, keg->uk_ipers) * keg->uk_ppera;
4282 
4283 #ifdef UMA_MD_SMALL_ALLOC
4284 	if (keg->uk_ppera > 1) {
4285 #else
4286 	if (1) {
4287 #endif
4288 		kva = kva_alloc((vm_size_t)pages * PAGE_SIZE);
4289 		if (kva == 0)
4290 			return (0);
4291 	} else
4292 		kva = 0;
4293 
4294 	ZONE_LOCK(zone);
4295 	MPASS(keg->uk_kva == 0);
4296 	keg->uk_kva = kva;
4297 	keg->uk_offset = 0;
4298 	zone->uz_max_items = pages * keg->uk_ipers;
4299 #ifdef UMA_MD_SMALL_ALLOC
4300 	keg->uk_allocf = (keg->uk_ppera > 1) ? noobj_alloc : uma_small_alloc;
4301 #else
4302 	keg->uk_allocf = noobj_alloc;
4303 #endif
4304 	keg->uk_flags |= UMA_ZFLAG_LIMIT | UMA_ZONE_NOFREE;
4305 	zone->uz_flags |= UMA_ZFLAG_LIMIT | UMA_ZONE_NOFREE;
4306 	zone_update_caches(zone);
4307 	ZONE_UNLOCK(zone);
4308 
4309 	return (1);
4310 }
4311 
4312 /* See uma.h */
4313 void
4314 uma_prealloc(uma_zone_t zone, int items)
4315 {
4316 	struct vm_domainset_iter di;
4317 	uma_domain_t dom;
4318 	uma_slab_t slab;
4319 	uma_keg_t keg;
4320 	int aflags, domain, slabs;
4321 
4322 	KEG_GET(zone, keg);
4323 	slabs = howmany(items, keg->uk_ipers);
4324 	while (slabs-- > 0) {
4325 		aflags = M_NOWAIT;
4326 		vm_domainset_iter_policy_ref_init(&di, &keg->uk_dr, &domain,
4327 		    &aflags);
4328 		for (;;) {
4329 			slab = keg_alloc_slab(keg, zone, domain, M_WAITOK,
4330 			    aflags);
4331 			if (slab != NULL) {
4332 				dom = &keg->uk_domain[slab->us_domain];
4333 				LIST_REMOVE(slab, us_link);
4334 				LIST_INSERT_HEAD(&dom->ud_free_slab, slab,
4335 				    us_link);
4336 				KEG_UNLOCK(keg, slab->us_domain);
4337 				break;
4338 			}
4339 			if (vm_domainset_iter_policy(&di, &domain) != 0)
4340 				vm_wait_doms(&keg->uk_dr.dr_policy->ds_mask);
4341 		}
4342 	}
4343 }
4344 
4345 /* See uma.h */
4346 void
4347 uma_reclaim(int req)
4348 {
4349 
4350 	CTR0(KTR_UMA, "UMA: vm asked us to release pages!");
4351 	sx_xlock(&uma_reclaim_lock);
4352 	bucket_enable();
4353 
4354 	switch (req) {
4355 	case UMA_RECLAIM_TRIM:
4356 		zone_foreach(zone_trim, NULL);
4357 		break;
4358 	case UMA_RECLAIM_DRAIN:
4359 	case UMA_RECLAIM_DRAIN_CPU:
4360 		zone_foreach(zone_drain, NULL);
4361 		if (req == UMA_RECLAIM_DRAIN_CPU) {
4362 			pcpu_cache_drain_safe(NULL);
4363 			zone_foreach(zone_drain, NULL);
4364 		}
4365 		break;
4366 	default:
4367 		panic("unhandled reclamation request %d", req);
4368 	}
4369 
4370 	/*
4371 	 * Some slabs may have been freed but this zone will be visited early
4372 	 * we visit again so that we can free pages that are empty once other
4373 	 * zones are drained.  We have to do the same for buckets.
4374 	 */
4375 	zone_drain(slabzones[0], NULL);
4376 	zone_drain(slabzones[1], NULL);
4377 	bucket_zone_drain();
4378 	sx_xunlock(&uma_reclaim_lock);
4379 }
4380 
4381 static volatile int uma_reclaim_needed;
4382 
4383 void
4384 uma_reclaim_wakeup(void)
4385 {
4386 
4387 	if (atomic_fetchadd_int(&uma_reclaim_needed, 1) == 0)
4388 		wakeup(uma_reclaim);
4389 }
4390 
4391 void
4392 uma_reclaim_worker(void *arg __unused)
4393 {
4394 
4395 	for (;;) {
4396 		sx_xlock(&uma_reclaim_lock);
4397 		while (atomic_load_int(&uma_reclaim_needed) == 0)
4398 			sx_sleep(uma_reclaim, &uma_reclaim_lock, PVM, "umarcl",
4399 			    hz);
4400 		sx_xunlock(&uma_reclaim_lock);
4401 		EVENTHANDLER_INVOKE(vm_lowmem, VM_LOW_KMEM);
4402 		uma_reclaim(UMA_RECLAIM_DRAIN_CPU);
4403 		atomic_store_int(&uma_reclaim_needed, 0);
4404 		/* Don't fire more than once per-second. */
4405 		pause("umarclslp", hz);
4406 	}
4407 }
4408 
4409 /* See uma.h */
4410 void
4411 uma_zone_reclaim(uma_zone_t zone, int req)
4412 {
4413 
4414 	switch (req) {
4415 	case UMA_RECLAIM_TRIM:
4416 		zone_trim(zone, NULL);
4417 		break;
4418 	case UMA_RECLAIM_DRAIN:
4419 		zone_drain(zone, NULL);
4420 		break;
4421 	case UMA_RECLAIM_DRAIN_CPU:
4422 		pcpu_cache_drain_safe(zone);
4423 		zone_drain(zone, NULL);
4424 		break;
4425 	default:
4426 		panic("unhandled reclamation request %d", req);
4427 	}
4428 }
4429 
4430 /* See uma.h */
4431 int
4432 uma_zone_exhausted(uma_zone_t zone)
4433 {
4434 
4435 	return (atomic_load_32(&zone->uz_sleepers) > 0);
4436 }
4437 
4438 unsigned long
4439 uma_limit(void)
4440 {
4441 
4442 	return (uma_kmem_limit);
4443 }
4444 
4445 void
4446 uma_set_limit(unsigned long limit)
4447 {
4448 
4449 	uma_kmem_limit = limit;
4450 }
4451 
4452 unsigned long
4453 uma_size(void)
4454 {
4455 
4456 	return (atomic_load_long(&uma_kmem_total));
4457 }
4458 
4459 long
4460 uma_avail(void)
4461 {
4462 
4463 	return (uma_kmem_limit - uma_size());
4464 }
4465 
4466 #ifdef DDB
4467 /*
4468  * Generate statistics across both the zone and its per-cpu cache's.  Return
4469  * desired statistics if the pointer is non-NULL for that statistic.
4470  *
4471  * Note: does not update the zone statistics, as it can't safely clear the
4472  * per-CPU cache statistic.
4473  *
4474  */
4475 static void
4476 uma_zone_sumstat(uma_zone_t z, long *cachefreep, uint64_t *allocsp,
4477     uint64_t *freesp, uint64_t *sleepsp, uint64_t *xdomainp)
4478 {
4479 	uma_cache_t cache;
4480 	uint64_t allocs, frees, sleeps, xdomain;
4481 	int cachefree, cpu;
4482 
4483 	allocs = frees = sleeps = xdomain = 0;
4484 	cachefree = 0;
4485 	CPU_FOREACH(cpu) {
4486 		cache = &z->uz_cpu[cpu];
4487 		cachefree += cache->uc_allocbucket.ucb_cnt;
4488 		cachefree += cache->uc_freebucket.ucb_cnt;
4489 		xdomain += cache->uc_crossbucket.ucb_cnt;
4490 		cachefree += cache->uc_crossbucket.ucb_cnt;
4491 		allocs += cache->uc_allocs;
4492 		frees += cache->uc_frees;
4493 	}
4494 	allocs += counter_u64_fetch(z->uz_allocs);
4495 	frees += counter_u64_fetch(z->uz_frees);
4496 	sleeps += z->uz_sleeps;
4497 	xdomain += z->uz_xdomain;
4498 	if (cachefreep != NULL)
4499 		*cachefreep = cachefree;
4500 	if (allocsp != NULL)
4501 		*allocsp = allocs;
4502 	if (freesp != NULL)
4503 		*freesp = frees;
4504 	if (sleepsp != NULL)
4505 		*sleepsp = sleeps;
4506 	if (xdomainp != NULL)
4507 		*xdomainp = xdomain;
4508 }
4509 #endif /* DDB */
4510 
4511 static int
4512 sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS)
4513 {
4514 	uma_keg_t kz;
4515 	uma_zone_t z;
4516 	int count;
4517 
4518 	count = 0;
4519 	rw_rlock(&uma_rwlock);
4520 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
4521 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
4522 			count++;
4523 	}
4524 	LIST_FOREACH(z, &uma_cachezones, uz_link)
4525 		count++;
4526 
4527 	rw_runlock(&uma_rwlock);
4528 	return (sysctl_handle_int(oidp, &count, 0, req));
4529 }
4530 
4531 static void
4532 uma_vm_zone_stats(struct uma_type_header *uth, uma_zone_t z, struct sbuf *sbuf,
4533     struct uma_percpu_stat *ups, bool internal)
4534 {
4535 	uma_zone_domain_t zdom;
4536 	uma_cache_t cache;
4537 	int i;
4538 
4539 
4540 	for (i = 0; i < vm_ndomains; i++) {
4541 		zdom = &z->uz_domain[i];
4542 		uth->uth_zone_free += zdom->uzd_nitems;
4543 	}
4544 	uth->uth_allocs = counter_u64_fetch(z->uz_allocs);
4545 	uth->uth_frees = counter_u64_fetch(z->uz_frees);
4546 	uth->uth_fails = counter_u64_fetch(z->uz_fails);
4547 	uth->uth_sleeps = z->uz_sleeps;
4548 	uth->uth_xdomain = z->uz_xdomain;
4549 
4550 	/*
4551 	 * While it is not normally safe to access the cache bucket pointers
4552 	 * while not on the CPU that owns the cache, we only allow the pointers
4553 	 * to be exchanged without the zone lock held, not invalidated, so
4554 	 * accept the possible race associated with bucket exchange during
4555 	 * monitoring.  Use atomic_load_ptr() to ensure that the bucket pointers
4556 	 * are loaded only once.
4557 	 */
4558 	for (i = 0; i < mp_maxid + 1; i++) {
4559 		bzero(&ups[i], sizeof(*ups));
4560 		if (internal || CPU_ABSENT(i))
4561 			continue;
4562 		cache = &z->uz_cpu[i];
4563 		ups[i].ups_cache_free += cache->uc_allocbucket.ucb_cnt;
4564 		ups[i].ups_cache_free += cache->uc_freebucket.ucb_cnt;
4565 		ups[i].ups_cache_free += cache->uc_crossbucket.ucb_cnt;
4566 		ups[i].ups_allocs = cache->uc_allocs;
4567 		ups[i].ups_frees = cache->uc_frees;
4568 	}
4569 }
4570 
4571 static int
4572 sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS)
4573 {
4574 	struct uma_stream_header ush;
4575 	struct uma_type_header uth;
4576 	struct uma_percpu_stat *ups;
4577 	struct sbuf sbuf;
4578 	uma_keg_t kz;
4579 	uma_zone_t z;
4580 	uint64_t items;
4581 	uint32_t kfree, pages;
4582 	int count, error, i;
4583 
4584 	error = sysctl_wire_old_buffer(req, 0);
4585 	if (error != 0)
4586 		return (error);
4587 	sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
4588 	sbuf_clear_flags(&sbuf, SBUF_INCLUDENUL);
4589 	ups = malloc((mp_maxid + 1) * sizeof(*ups), M_TEMP, M_WAITOK);
4590 
4591 	count = 0;
4592 	rw_rlock(&uma_rwlock);
4593 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
4594 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
4595 			count++;
4596 	}
4597 
4598 	LIST_FOREACH(z, &uma_cachezones, uz_link)
4599 		count++;
4600 
4601 	/*
4602 	 * Insert stream header.
4603 	 */
4604 	bzero(&ush, sizeof(ush));
4605 	ush.ush_version = UMA_STREAM_VERSION;
4606 	ush.ush_maxcpus = (mp_maxid + 1);
4607 	ush.ush_count = count;
4608 	(void)sbuf_bcat(&sbuf, &ush, sizeof(ush));
4609 
4610 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
4611 		kfree = pages = 0;
4612 		for (i = 0; i < vm_ndomains; i++) {
4613 			kfree += kz->uk_domain[i].ud_free;
4614 			pages += kz->uk_domain[i].ud_pages;
4615 		}
4616 		LIST_FOREACH(z, &kz->uk_zones, uz_link) {
4617 			bzero(&uth, sizeof(uth));
4618 			ZONE_LOCK(z);
4619 			strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
4620 			uth.uth_align = kz->uk_align;
4621 			uth.uth_size = kz->uk_size;
4622 			uth.uth_rsize = kz->uk_rsize;
4623 			if (z->uz_max_items > 0) {
4624 				items = UZ_ITEMS_COUNT(z->uz_items);
4625 				uth.uth_pages = (items / kz->uk_ipers) *
4626 					kz->uk_ppera;
4627 			} else
4628 				uth.uth_pages = pages;
4629 			uth.uth_maxpages = (z->uz_max_items / kz->uk_ipers) *
4630 			    kz->uk_ppera;
4631 			uth.uth_limit = z->uz_max_items;
4632 			uth.uth_keg_free = kfree;
4633 
4634 			/*
4635 			 * A zone is secondary is it is not the first entry
4636 			 * on the keg's zone list.
4637 			 */
4638 			if ((z->uz_flags & UMA_ZONE_SECONDARY) &&
4639 			    (LIST_FIRST(&kz->uk_zones) != z))
4640 				uth.uth_zone_flags = UTH_ZONE_SECONDARY;
4641 			uma_vm_zone_stats(&uth, z, &sbuf, ups,
4642 			    kz->uk_flags & UMA_ZFLAG_INTERNAL);
4643 			ZONE_UNLOCK(z);
4644 			(void)sbuf_bcat(&sbuf, &uth, sizeof(uth));
4645 			for (i = 0; i < mp_maxid + 1; i++)
4646 				(void)sbuf_bcat(&sbuf, &ups[i], sizeof(ups[i]));
4647 		}
4648 	}
4649 	LIST_FOREACH(z, &uma_cachezones, uz_link) {
4650 		bzero(&uth, sizeof(uth));
4651 		ZONE_LOCK(z);
4652 		strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
4653 		uth.uth_size = z->uz_size;
4654 		uma_vm_zone_stats(&uth, z, &sbuf, ups, false);
4655 		ZONE_UNLOCK(z);
4656 		(void)sbuf_bcat(&sbuf, &uth, sizeof(uth));
4657 		for (i = 0; i < mp_maxid + 1; i++)
4658 			(void)sbuf_bcat(&sbuf, &ups[i], sizeof(ups[i]));
4659 	}
4660 
4661 	rw_runlock(&uma_rwlock);
4662 	error = sbuf_finish(&sbuf);
4663 	sbuf_delete(&sbuf);
4664 	free(ups, M_TEMP);
4665 	return (error);
4666 }
4667 
4668 int
4669 sysctl_handle_uma_zone_max(SYSCTL_HANDLER_ARGS)
4670 {
4671 	uma_zone_t zone = *(uma_zone_t *)arg1;
4672 	int error, max;
4673 
4674 	max = uma_zone_get_max(zone);
4675 	error = sysctl_handle_int(oidp, &max, 0, req);
4676 	if (error || !req->newptr)
4677 		return (error);
4678 
4679 	uma_zone_set_max(zone, max);
4680 
4681 	return (0);
4682 }
4683 
4684 int
4685 sysctl_handle_uma_zone_cur(SYSCTL_HANDLER_ARGS)
4686 {
4687 	uma_zone_t zone;
4688 	int cur;
4689 
4690 	/*
4691 	 * Some callers want to add sysctls for global zones that
4692 	 * may not yet exist so they pass a pointer to a pointer.
4693 	 */
4694 	if (arg2 == 0)
4695 		zone = *(uma_zone_t *)arg1;
4696 	else
4697 		zone = arg1;
4698 	cur = uma_zone_get_cur(zone);
4699 	return (sysctl_handle_int(oidp, &cur, 0, req));
4700 }
4701 
4702 static int
4703 sysctl_handle_uma_zone_allocs(SYSCTL_HANDLER_ARGS)
4704 {
4705 	uma_zone_t zone = arg1;
4706 	uint64_t cur;
4707 
4708 	cur = uma_zone_get_allocs(zone);
4709 	return (sysctl_handle_64(oidp, &cur, 0, req));
4710 }
4711 
4712 static int
4713 sysctl_handle_uma_zone_frees(SYSCTL_HANDLER_ARGS)
4714 {
4715 	uma_zone_t zone = arg1;
4716 	uint64_t cur;
4717 
4718 	cur = uma_zone_get_frees(zone);
4719 	return (sysctl_handle_64(oidp, &cur, 0, req));
4720 }
4721 
4722 static int
4723 sysctl_handle_uma_zone_flags(SYSCTL_HANDLER_ARGS)
4724 {
4725 	struct sbuf sbuf;
4726 	uma_zone_t zone = arg1;
4727 	int error;
4728 
4729 	sbuf_new_for_sysctl(&sbuf, NULL, 0, req);
4730 	if (zone->uz_flags != 0)
4731 		sbuf_printf(&sbuf, "0x%b", zone->uz_flags, PRINT_UMA_ZFLAGS);
4732 	else
4733 		sbuf_printf(&sbuf, "0");
4734 	error = sbuf_finish(&sbuf);
4735 	sbuf_delete(&sbuf);
4736 
4737 	return (error);
4738 }
4739 
4740 static int
4741 sysctl_handle_uma_slab_efficiency(SYSCTL_HANDLER_ARGS)
4742 {
4743 	uma_keg_t keg = arg1;
4744 	int avail, effpct, total;
4745 
4746 	total = keg->uk_ppera * PAGE_SIZE;
4747 	if ((keg->uk_flags & UMA_ZFLAG_OFFPAGE) != 0)
4748 		total += slabzone(keg->uk_ipers)->uz_keg->uk_rsize;
4749 	/*
4750 	 * We consider the client's requested size and alignment here, not the
4751 	 * real size determination uk_rsize, because we also adjust the real
4752 	 * size for internal implementation reasons (max bitset size).
4753 	 */
4754 	avail = keg->uk_ipers * roundup2(keg->uk_size, keg->uk_align + 1);
4755 	if ((keg->uk_flags & UMA_ZONE_PCPU) != 0)
4756 		avail *= mp_maxid + 1;
4757 	effpct = 100 * avail / total;
4758 	return (sysctl_handle_int(oidp, &effpct, 0, req));
4759 }
4760 
4761 static int
4762 sysctl_handle_uma_zone_items(SYSCTL_HANDLER_ARGS)
4763 {
4764 	uma_zone_t zone = arg1;
4765 	uint64_t cur;
4766 
4767 	cur = UZ_ITEMS_COUNT(atomic_load_64(&zone->uz_items));
4768 	return (sysctl_handle_64(oidp, &cur, 0, req));
4769 }
4770 
4771 #ifdef INVARIANTS
4772 static uma_slab_t
4773 uma_dbg_getslab(uma_zone_t zone, void *item)
4774 {
4775 	uma_slab_t slab;
4776 	uma_keg_t keg;
4777 	uint8_t *mem;
4778 
4779 	/*
4780 	 * It is safe to return the slab here even though the
4781 	 * zone is unlocked because the item's allocation state
4782 	 * essentially holds a reference.
4783 	 */
4784 	mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
4785 	if ((zone->uz_flags & UMA_ZFLAG_CACHE) != 0)
4786 		return (NULL);
4787 	if (zone->uz_flags & UMA_ZFLAG_VTOSLAB)
4788 		return (vtoslab((vm_offset_t)mem));
4789 	keg = zone->uz_keg;
4790 	if ((keg->uk_flags & UMA_ZFLAG_HASH) == 0)
4791 		return ((uma_slab_t)(mem + keg->uk_pgoff));
4792 	KEG_LOCK(keg, 0);
4793 	slab = hash_sfind(&keg->uk_hash, mem);
4794 	KEG_UNLOCK(keg, 0);
4795 
4796 	return (slab);
4797 }
4798 
4799 static bool
4800 uma_dbg_zskip(uma_zone_t zone, void *mem)
4801 {
4802 
4803 	if ((zone->uz_flags & UMA_ZFLAG_CACHE) != 0)
4804 		return (true);
4805 
4806 	return (uma_dbg_kskip(zone->uz_keg, mem));
4807 }
4808 
4809 static bool
4810 uma_dbg_kskip(uma_keg_t keg, void *mem)
4811 {
4812 	uintptr_t idx;
4813 
4814 	if (dbg_divisor == 0)
4815 		return (true);
4816 
4817 	if (dbg_divisor == 1)
4818 		return (false);
4819 
4820 	idx = (uintptr_t)mem >> PAGE_SHIFT;
4821 	if (keg->uk_ipers > 1) {
4822 		idx *= keg->uk_ipers;
4823 		idx += ((uintptr_t)mem & PAGE_MASK) / keg->uk_rsize;
4824 	}
4825 
4826 	if ((idx / dbg_divisor) * dbg_divisor != idx) {
4827 		counter_u64_add(uma_skip_cnt, 1);
4828 		return (true);
4829 	}
4830 	counter_u64_add(uma_dbg_cnt, 1);
4831 
4832 	return (false);
4833 }
4834 
4835 /*
4836  * Set up the slab's freei data such that uma_dbg_free can function.
4837  *
4838  */
4839 static void
4840 uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item)
4841 {
4842 	uma_keg_t keg;
4843 	int freei;
4844 
4845 	if (slab == NULL) {
4846 		slab = uma_dbg_getslab(zone, item);
4847 		if (slab == NULL)
4848 			panic("uma: item %p did not belong to zone %s\n",
4849 			    item, zone->uz_name);
4850 	}
4851 	keg = zone->uz_keg;
4852 	freei = slab_item_index(slab, keg, item);
4853 
4854 	if (BIT_ISSET(keg->uk_ipers, freei, slab_dbg_bits(slab, keg)))
4855 		panic("Duplicate alloc of %p from zone %p(%s) slab %p(%d)\n",
4856 		    item, zone, zone->uz_name, slab, freei);
4857 	BIT_SET_ATOMIC(keg->uk_ipers, freei, slab_dbg_bits(slab, keg));
4858 }
4859 
4860 /*
4861  * Verifies freed addresses.  Checks for alignment, valid slab membership
4862  * and duplicate frees.
4863  *
4864  */
4865 static void
4866 uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item)
4867 {
4868 	uma_keg_t keg;
4869 	int freei;
4870 
4871 	if (slab == NULL) {
4872 		slab = uma_dbg_getslab(zone, item);
4873 		if (slab == NULL)
4874 			panic("uma: Freed item %p did not belong to zone %s\n",
4875 			    item, zone->uz_name);
4876 	}
4877 	keg = zone->uz_keg;
4878 	freei = slab_item_index(slab, keg, item);
4879 
4880 	if (freei >= keg->uk_ipers)
4881 		panic("Invalid free of %p from zone %p(%s) slab %p(%d)\n",
4882 		    item, zone, zone->uz_name, slab, freei);
4883 
4884 	if (slab_item(slab, keg, freei) != item)
4885 		panic("Unaligned free of %p from zone %p(%s) slab %p(%d)\n",
4886 		    item, zone, zone->uz_name, slab, freei);
4887 
4888 	if (!BIT_ISSET(keg->uk_ipers, freei, slab_dbg_bits(slab, keg)))
4889 		panic("Duplicate free of %p from zone %p(%s) slab %p(%d)\n",
4890 		    item, zone, zone->uz_name, slab, freei);
4891 
4892 	BIT_CLR_ATOMIC(keg->uk_ipers, freei, slab_dbg_bits(slab, keg));
4893 }
4894 #endif /* INVARIANTS */
4895 
4896 #ifdef DDB
4897 static int64_t
4898 get_uma_stats(uma_keg_t kz, uma_zone_t z, uint64_t *allocs, uint64_t *used,
4899     uint64_t *sleeps, long *cachefree, uint64_t *xdomain)
4900 {
4901 	uint64_t frees;
4902 	int i;
4903 
4904 	if (kz->uk_flags & UMA_ZFLAG_INTERNAL) {
4905 		*allocs = counter_u64_fetch(z->uz_allocs);
4906 		frees = counter_u64_fetch(z->uz_frees);
4907 		*sleeps = z->uz_sleeps;
4908 		*cachefree = 0;
4909 		*xdomain = 0;
4910 	} else
4911 		uma_zone_sumstat(z, cachefree, allocs, &frees, sleeps,
4912 		    xdomain);
4913 	for (i = 0; i < vm_ndomains; i++) {
4914 		*cachefree += z->uz_domain[i].uzd_nitems;
4915 		if (!((z->uz_flags & UMA_ZONE_SECONDARY) &&
4916 		    (LIST_FIRST(&kz->uk_zones) != z)))
4917 			*cachefree += kz->uk_domain[i].ud_free;
4918 	}
4919 	*used = *allocs - frees;
4920 	return (((int64_t)*used + *cachefree) * kz->uk_size);
4921 }
4922 
4923 DB_SHOW_COMMAND(uma, db_show_uma)
4924 {
4925 	const char *fmt_hdr, *fmt_entry;
4926 	uma_keg_t kz;
4927 	uma_zone_t z;
4928 	uint64_t allocs, used, sleeps, xdomain;
4929 	long cachefree;
4930 	/* variables for sorting */
4931 	uma_keg_t cur_keg;
4932 	uma_zone_t cur_zone, last_zone;
4933 	int64_t cur_size, last_size, size;
4934 	int ties;
4935 
4936 	/* /i option produces machine-parseable CSV output */
4937 	if (modif[0] == 'i') {
4938 		fmt_hdr = "%s,%s,%s,%s,%s,%s,%s,%s,%s\n";
4939 		fmt_entry = "\"%s\",%ju,%jd,%ld,%ju,%ju,%u,%jd,%ju\n";
4940 	} else {
4941 		fmt_hdr = "%18s %6s %7s %7s %11s %7s %7s %10s %8s\n";
4942 		fmt_entry = "%18s %6ju %7jd %7ld %11ju %7ju %7u %10jd %8ju\n";
4943 	}
4944 
4945 	db_printf(fmt_hdr, "Zone", "Size", "Used", "Free", "Requests",
4946 	    "Sleeps", "Bucket", "Total Mem", "XFree");
4947 
4948 	/* Sort the zones with largest size first. */
4949 	last_zone = NULL;
4950 	last_size = INT64_MAX;
4951 	for (;;) {
4952 		cur_zone = NULL;
4953 		cur_size = -1;
4954 		ties = 0;
4955 		LIST_FOREACH(kz, &uma_kegs, uk_link) {
4956 			LIST_FOREACH(z, &kz->uk_zones, uz_link) {
4957 				/*
4958 				 * In the case of size ties, print out zones
4959 				 * in the order they are encountered.  That is,
4960 				 * when we encounter the most recently output
4961 				 * zone, we have already printed all preceding
4962 				 * ties, and we must print all following ties.
4963 				 */
4964 				if (z == last_zone) {
4965 					ties = 1;
4966 					continue;
4967 				}
4968 				size = get_uma_stats(kz, z, &allocs, &used,
4969 				    &sleeps, &cachefree, &xdomain);
4970 				if (size > cur_size && size < last_size + ties)
4971 				{
4972 					cur_size = size;
4973 					cur_zone = z;
4974 					cur_keg = kz;
4975 				}
4976 			}
4977 		}
4978 		if (cur_zone == NULL)
4979 			break;
4980 
4981 		size = get_uma_stats(cur_keg, cur_zone, &allocs, &used,
4982 		    &sleeps, &cachefree, &xdomain);
4983 		db_printf(fmt_entry, cur_zone->uz_name,
4984 		    (uintmax_t)cur_keg->uk_size, (intmax_t)used, cachefree,
4985 		    (uintmax_t)allocs, (uintmax_t)sleeps,
4986 		    (unsigned)cur_zone->uz_bucket_size, (intmax_t)size,
4987 		    xdomain);
4988 
4989 		if (db_pager_quit)
4990 			return;
4991 		last_zone = cur_zone;
4992 		last_size = cur_size;
4993 	}
4994 }
4995 
4996 DB_SHOW_COMMAND(umacache, db_show_umacache)
4997 {
4998 	uma_zone_t z;
4999 	uint64_t allocs, frees;
5000 	long cachefree;
5001 	int i;
5002 
5003 	db_printf("%18s %8s %8s %8s %12s %8s\n", "Zone", "Size", "Used", "Free",
5004 	    "Requests", "Bucket");
5005 	LIST_FOREACH(z, &uma_cachezones, uz_link) {
5006 		uma_zone_sumstat(z, &cachefree, &allocs, &frees, NULL, NULL);
5007 		for (i = 0; i < vm_ndomains; i++)
5008 			cachefree += z->uz_domain[i].uzd_nitems;
5009 		db_printf("%18s %8ju %8jd %8ld %12ju %8u\n",
5010 		    z->uz_name, (uintmax_t)z->uz_size,
5011 		    (intmax_t)(allocs - frees), cachefree,
5012 		    (uintmax_t)allocs, z->uz_bucket_size);
5013 		if (db_pager_quit)
5014 			return;
5015 	}
5016 }
5017 #endif	/* DDB */
5018