xref: /freebsd/sys/vm/uma_core.c (revision 5e71fdc20dd45d9202261dd82cb68b16197beba6)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2002-2005, 2009, 2013 Jeffrey Roberson <jeff@FreeBSD.org>
5  * Copyright (c) 2004, 2005 Bosko Milekic <bmilekic@FreeBSD.org>
6  * Copyright (c) 2004-2006 Robert N. M. Watson
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice unmodified, this list of conditions, and the following
14  *    disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 /*
32  * uma_core.c  Implementation of the Universal Memory allocator
33  *
34  * This allocator is intended to replace the multitude of similar object caches
35  * in the standard FreeBSD kernel.  The intent is to be flexible as well as
36  * efficient.  A primary design goal is to return unused memory to the rest of
37  * the system.  This will make the system as a whole more flexible due to the
38  * ability to move memory to subsystems which most need it instead of leaving
39  * pools of reserved memory unused.
40  *
41  * The basic ideas stem from similar slab/zone based allocators whose algorithms
42  * are well known.
43  *
44  */
45 
46 /*
47  * TODO:
48  *	- Improve memory usage for large allocations
49  *	- Investigate cache size adjustments
50  */
51 
52 #include <sys/cdefs.h>
53 __FBSDID("$FreeBSD$");
54 
55 #include "opt_ddb.h"
56 #include "opt_param.h"
57 #include "opt_vm.h"
58 
59 #include <sys/param.h>
60 #include <sys/systm.h>
61 #include <sys/bitset.h>
62 #include <sys/eventhandler.h>
63 #include <sys/kernel.h>
64 #include <sys/types.h>
65 #include <sys/limits.h>
66 #include <sys/queue.h>
67 #include <sys/malloc.h>
68 #include <sys/ktr.h>
69 #include <sys/lock.h>
70 #include <sys/sysctl.h>
71 #include <sys/mutex.h>
72 #include <sys/proc.h>
73 #include <sys/random.h>
74 #include <sys/rwlock.h>
75 #include <sys/sbuf.h>
76 #include <sys/sched.h>
77 #include <sys/smp.h>
78 #include <sys/taskqueue.h>
79 #include <sys/vmmeter.h>
80 
81 #include <vm/vm.h>
82 #include <vm/vm_object.h>
83 #include <vm/vm_page.h>
84 #include <vm/vm_pageout.h>
85 #include <vm/vm_param.h>
86 #include <vm/vm_phys.h>
87 #include <vm/vm_map.h>
88 #include <vm/vm_kern.h>
89 #include <vm/vm_extern.h>
90 #include <vm/uma.h>
91 #include <vm/uma_int.h>
92 #include <vm/uma_dbg.h>
93 
94 #include <ddb/ddb.h>
95 
96 #ifdef DEBUG_MEMGUARD
97 #include <vm/memguard.h>
98 #endif
99 
100 /*
101  * This is the zone and keg from which all zones are spawned.
102  */
103 static uma_zone_t kegs;
104 static uma_zone_t zones;
105 
106 /* This is the zone from which all offpage uma_slab_ts are allocated. */
107 static uma_zone_t slabzone;
108 
109 /*
110  * The initial hash tables come out of this zone so they can be allocated
111  * prior to malloc coming up.
112  */
113 static uma_zone_t hashzone;
114 
115 /* The boot-time adjusted value for cache line alignment. */
116 int uma_align_cache = 64 - 1;
117 
118 static MALLOC_DEFINE(M_UMAHASH, "UMAHash", "UMA Hash Buckets");
119 
120 /*
121  * Are we allowed to allocate buckets?
122  */
123 static int bucketdisable = 1;
124 
125 /* Linked list of all kegs in the system */
126 static LIST_HEAD(,uma_keg) uma_kegs = LIST_HEAD_INITIALIZER(uma_kegs);
127 
128 /* Linked list of all cache-only zones in the system */
129 static LIST_HEAD(,uma_zone) uma_cachezones =
130     LIST_HEAD_INITIALIZER(uma_cachezones);
131 
132 /* This RW lock protects the keg list */
133 static struct rwlock_padalign __exclusive_cache_line uma_rwlock;
134 
135 /*
136  * Pointer and counter to pool of pages, that is preallocated at
137  * startup to bootstrap UMA.
138  */
139 static char *bootmem;
140 static int boot_pages;
141 
142 static struct sx uma_drain_lock;
143 
144 /* kmem soft limit. */
145 static unsigned long uma_kmem_limit = LONG_MAX;
146 static volatile unsigned long uma_kmem_total;
147 
148 /* Is the VM done starting up? */
149 static enum { BOOT_COLD = 0, BOOT_STRAPPED, BOOT_PAGEALLOC, BOOT_BUCKETS,
150     BOOT_RUNNING } booted = BOOT_COLD;
151 
152 /*
153  * This is the handle used to schedule events that need to happen
154  * outside of the allocation fast path.
155  */
156 static struct callout uma_callout;
157 #define	UMA_TIMEOUT	20		/* Seconds for callout interval. */
158 
159 /*
160  * This structure is passed as the zone ctor arg so that I don't have to create
161  * a special allocation function just for zones.
162  */
163 struct uma_zctor_args {
164 	const char *name;
165 	size_t size;
166 	uma_ctor ctor;
167 	uma_dtor dtor;
168 	uma_init uminit;
169 	uma_fini fini;
170 	uma_import import;
171 	uma_release release;
172 	void *arg;
173 	uma_keg_t keg;
174 	int align;
175 	uint32_t flags;
176 };
177 
178 struct uma_kctor_args {
179 	uma_zone_t zone;
180 	size_t size;
181 	uma_init uminit;
182 	uma_fini fini;
183 	int align;
184 	uint32_t flags;
185 };
186 
187 struct uma_bucket_zone {
188 	uma_zone_t	ubz_zone;
189 	char		*ubz_name;
190 	int		ubz_entries;	/* Number of items it can hold. */
191 	int		ubz_maxsize;	/* Maximum allocation size per-item. */
192 };
193 
194 /*
195  * Compute the actual number of bucket entries to pack them in power
196  * of two sizes for more efficient space utilization.
197  */
198 #define	BUCKET_SIZE(n)						\
199     (((sizeof(void *) * (n)) - sizeof(struct uma_bucket)) / sizeof(void *))
200 
201 #define	BUCKET_MAX	BUCKET_SIZE(256)
202 
203 struct uma_bucket_zone bucket_zones[] = {
204 	{ NULL, "4 Bucket", BUCKET_SIZE(4), 4096 },
205 	{ NULL, "6 Bucket", BUCKET_SIZE(6), 3072 },
206 	{ NULL, "8 Bucket", BUCKET_SIZE(8), 2048 },
207 	{ NULL, "12 Bucket", BUCKET_SIZE(12), 1536 },
208 	{ NULL, "16 Bucket", BUCKET_SIZE(16), 1024 },
209 	{ NULL, "32 Bucket", BUCKET_SIZE(32), 512 },
210 	{ NULL, "64 Bucket", BUCKET_SIZE(64), 256 },
211 	{ NULL, "128 Bucket", BUCKET_SIZE(128), 128 },
212 	{ NULL, "256 Bucket", BUCKET_SIZE(256), 64 },
213 	{ NULL, NULL, 0}
214 };
215 
216 /*
217  * Flags and enumerations to be passed to internal functions.
218  */
219 enum zfreeskip { SKIP_NONE = 0, SKIP_DTOR, SKIP_FINI };
220 
221 #define	UMA_ANYDOMAIN	-1	/* Special value for domain search. */
222 
223 /* Prototypes.. */
224 
225 int	uma_startup_count(int);
226 void	uma_startup(void *, int);
227 void	uma_startup1(void);
228 void	uma_startup2(void);
229 
230 static void *noobj_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
231 static void *page_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
232 static void *pcpu_page_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
233 static void *startup_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
234 static void page_free(void *, vm_size_t, uint8_t);
235 static void pcpu_page_free(void *, vm_size_t, uint8_t);
236 static uma_slab_t keg_alloc_slab(uma_keg_t, uma_zone_t, int, int);
237 static void cache_drain(uma_zone_t);
238 static void bucket_drain(uma_zone_t, uma_bucket_t);
239 static void bucket_cache_drain(uma_zone_t zone);
240 static int keg_ctor(void *, int, void *, int);
241 static void keg_dtor(void *, int, void *);
242 static int zone_ctor(void *, int, void *, int);
243 static void zone_dtor(void *, int, void *);
244 static int zero_init(void *, int, int);
245 static void keg_small_init(uma_keg_t keg);
246 static void keg_large_init(uma_keg_t keg);
247 static void zone_foreach(void (*zfunc)(uma_zone_t));
248 static void zone_timeout(uma_zone_t zone);
249 static int hash_alloc(struct uma_hash *);
250 static int hash_expand(struct uma_hash *, struct uma_hash *);
251 static void hash_free(struct uma_hash *hash);
252 static void uma_timeout(void *);
253 static void uma_startup3(void);
254 static void *zone_alloc_item(uma_zone_t, void *, int, int);
255 static void zone_free_item(uma_zone_t, void *, void *, enum zfreeskip);
256 static void bucket_enable(void);
257 static void bucket_init(void);
258 static uma_bucket_t bucket_alloc(uma_zone_t zone, void *, int);
259 static void bucket_free(uma_zone_t zone, uma_bucket_t, void *);
260 static void bucket_zone_drain(void);
261 static uma_bucket_t zone_alloc_bucket(uma_zone_t, void *, int, int);
262 static uma_slab_t zone_fetch_slab(uma_zone_t, uma_keg_t, int, int);
263 static uma_slab_t zone_fetch_slab_multi(uma_zone_t, uma_keg_t, int, int);
264 static void *slab_alloc_item(uma_keg_t keg, uma_slab_t slab);
265 static void slab_free_item(uma_keg_t keg, uma_slab_t slab, void *item);
266 static uma_keg_t uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit,
267     uma_fini fini, int align, uint32_t flags);
268 static int zone_import(uma_zone_t, void **, int, int, int);
269 static void zone_release(uma_zone_t, void **, int);
270 static void uma_zero_item(void *, uma_zone_t);
271 
272 void uma_print_zone(uma_zone_t);
273 void uma_print_stats(void);
274 static int sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS);
275 static int sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS);
276 
277 #ifdef INVARIANTS
278 static bool uma_dbg_kskip(uma_keg_t keg, void *mem);
279 static bool uma_dbg_zskip(uma_zone_t zone, void *mem);
280 static void uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item);
281 static void uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item);
282 
283 static SYSCTL_NODE(_vm, OID_AUTO, debug, CTLFLAG_RD, 0,
284     "Memory allocation debugging");
285 
286 static u_int dbg_divisor = 1;
287 SYSCTL_UINT(_vm_debug, OID_AUTO, divisor,
288     CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &dbg_divisor, 0,
289     "Debug & thrash every this item in memory allocator");
290 
291 static counter_u64_t uma_dbg_cnt = EARLY_COUNTER;
292 static counter_u64_t uma_skip_cnt = EARLY_COUNTER;
293 SYSCTL_COUNTER_U64(_vm_debug, OID_AUTO, trashed, CTLFLAG_RD,
294     &uma_dbg_cnt, "memory items debugged");
295 SYSCTL_COUNTER_U64(_vm_debug, OID_AUTO, skipped, CTLFLAG_RD,
296     &uma_skip_cnt, "memory items skipped, not debugged");
297 #endif
298 
299 SYSINIT(uma_startup3, SI_SUB_VM_CONF, SI_ORDER_SECOND, uma_startup3, NULL);
300 
301 SYSCTL_PROC(_vm, OID_AUTO, zone_count, CTLFLAG_RD|CTLTYPE_INT,
302     0, 0, sysctl_vm_zone_count, "I", "Number of UMA zones");
303 
304 SYSCTL_PROC(_vm, OID_AUTO, zone_stats, CTLFLAG_RD|CTLTYPE_STRUCT,
305     0, 0, sysctl_vm_zone_stats, "s,struct uma_type_header", "Zone Stats");
306 
307 static int zone_warnings = 1;
308 SYSCTL_INT(_vm, OID_AUTO, zone_warnings, CTLFLAG_RWTUN, &zone_warnings, 0,
309     "Warn when UMA zones becomes full");
310 
311 /* Adjust bytes under management by UMA. */
312 static inline void
313 uma_total_dec(unsigned long size)
314 {
315 
316 	atomic_subtract_long(&uma_kmem_total, size);
317 }
318 
319 static inline void
320 uma_total_inc(unsigned long size)
321 {
322 
323 	if (atomic_fetchadd_long(&uma_kmem_total, size) > uma_kmem_limit)
324 		uma_reclaim_wakeup();
325 }
326 
327 /*
328  * This routine checks to see whether or not it's safe to enable buckets.
329  */
330 static void
331 bucket_enable(void)
332 {
333 	bucketdisable = vm_page_count_min();
334 }
335 
336 /*
337  * Initialize bucket_zones, the array of zones of buckets of various sizes.
338  *
339  * For each zone, calculate the memory required for each bucket, consisting
340  * of the header and an array of pointers.
341  */
342 static void
343 bucket_init(void)
344 {
345 	struct uma_bucket_zone *ubz;
346 	int size;
347 
348 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++) {
349 		size = roundup(sizeof(struct uma_bucket), sizeof(void *));
350 		size += sizeof(void *) * ubz->ubz_entries;
351 		ubz->ubz_zone = uma_zcreate(ubz->ubz_name, size,
352 		    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR,
353 		    UMA_ZONE_MTXCLASS | UMA_ZFLAG_BUCKET | UMA_ZONE_NUMA);
354 	}
355 }
356 
357 /*
358  * Given a desired number of entries for a bucket, return the zone from which
359  * to allocate the bucket.
360  */
361 static struct uma_bucket_zone *
362 bucket_zone_lookup(int entries)
363 {
364 	struct uma_bucket_zone *ubz;
365 
366 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
367 		if (ubz->ubz_entries >= entries)
368 			return (ubz);
369 	ubz--;
370 	return (ubz);
371 }
372 
373 static int
374 bucket_select(int size)
375 {
376 	struct uma_bucket_zone *ubz;
377 
378 	ubz = &bucket_zones[0];
379 	if (size > ubz->ubz_maxsize)
380 		return MAX((ubz->ubz_maxsize * ubz->ubz_entries) / size, 1);
381 
382 	for (; ubz->ubz_entries != 0; ubz++)
383 		if (ubz->ubz_maxsize < size)
384 			break;
385 	ubz--;
386 	return (ubz->ubz_entries);
387 }
388 
389 static uma_bucket_t
390 bucket_alloc(uma_zone_t zone, void *udata, int flags)
391 {
392 	struct uma_bucket_zone *ubz;
393 	uma_bucket_t bucket;
394 
395 	/*
396 	 * This is to stop us from allocating per cpu buckets while we're
397 	 * running out of vm.boot_pages.  Otherwise, we would exhaust the
398 	 * boot pages.  This also prevents us from allocating buckets in
399 	 * low memory situations.
400 	 */
401 	if (bucketdisable)
402 		return (NULL);
403 	/*
404 	 * To limit bucket recursion we store the original zone flags
405 	 * in a cookie passed via zalloc_arg/zfree_arg.  This allows the
406 	 * NOVM flag to persist even through deep recursions.  We also
407 	 * store ZFLAG_BUCKET once we have recursed attempting to allocate
408 	 * a bucket for a bucket zone so we do not allow infinite bucket
409 	 * recursion.  This cookie will even persist to frees of unused
410 	 * buckets via the allocation path or bucket allocations in the
411 	 * free path.
412 	 */
413 	if ((zone->uz_flags & UMA_ZFLAG_BUCKET) == 0)
414 		udata = (void *)(uintptr_t)zone->uz_flags;
415 	else {
416 		if ((uintptr_t)udata & UMA_ZFLAG_BUCKET)
417 			return (NULL);
418 		udata = (void *)((uintptr_t)udata | UMA_ZFLAG_BUCKET);
419 	}
420 	if ((uintptr_t)udata & UMA_ZFLAG_CACHEONLY)
421 		flags |= M_NOVM;
422 	ubz = bucket_zone_lookup(zone->uz_count);
423 	if (ubz->ubz_zone == zone && (ubz + 1)->ubz_entries != 0)
424 		ubz++;
425 	bucket = uma_zalloc_arg(ubz->ubz_zone, udata, flags);
426 	if (bucket) {
427 #ifdef INVARIANTS
428 		bzero(bucket->ub_bucket, sizeof(void *) * ubz->ubz_entries);
429 #endif
430 		bucket->ub_cnt = 0;
431 		bucket->ub_entries = ubz->ubz_entries;
432 	}
433 
434 	return (bucket);
435 }
436 
437 static void
438 bucket_free(uma_zone_t zone, uma_bucket_t bucket, void *udata)
439 {
440 	struct uma_bucket_zone *ubz;
441 
442 	KASSERT(bucket->ub_cnt == 0,
443 	    ("bucket_free: Freeing a non free bucket."));
444 	if ((zone->uz_flags & UMA_ZFLAG_BUCKET) == 0)
445 		udata = (void *)(uintptr_t)zone->uz_flags;
446 	ubz = bucket_zone_lookup(bucket->ub_entries);
447 	uma_zfree_arg(ubz->ubz_zone, bucket, udata);
448 }
449 
450 static void
451 bucket_zone_drain(void)
452 {
453 	struct uma_bucket_zone *ubz;
454 
455 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
456 		zone_drain(ubz->ubz_zone);
457 }
458 
459 static void
460 zone_log_warning(uma_zone_t zone)
461 {
462 	static const struct timeval warninterval = { 300, 0 };
463 
464 	if (!zone_warnings || zone->uz_warning == NULL)
465 		return;
466 
467 	if (ratecheck(&zone->uz_ratecheck, &warninterval))
468 		printf("[zone: %s] %s\n", zone->uz_name, zone->uz_warning);
469 }
470 
471 static inline void
472 zone_maxaction(uma_zone_t zone)
473 {
474 
475 	if (zone->uz_maxaction.ta_func != NULL)
476 		taskqueue_enqueue(taskqueue_thread, &zone->uz_maxaction);
477 }
478 
479 static void
480 zone_foreach_keg(uma_zone_t zone, void (*kegfn)(uma_keg_t))
481 {
482 	uma_klink_t klink;
483 
484 	LIST_FOREACH(klink, &zone->uz_kegs, kl_link)
485 		kegfn(klink->kl_keg);
486 }
487 
488 /*
489  * Routine called by timeout which is used to fire off some time interval
490  * based calculations.  (stats, hash size, etc.)
491  *
492  * Arguments:
493  *	arg   Unused
494  *
495  * Returns:
496  *	Nothing
497  */
498 static void
499 uma_timeout(void *unused)
500 {
501 	bucket_enable();
502 	zone_foreach(zone_timeout);
503 
504 	/* Reschedule this event */
505 	callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
506 }
507 
508 /*
509  * Routine to perform timeout driven calculations.  This expands the
510  * hashes and does per cpu statistics aggregation.
511  *
512  *  Returns nothing.
513  */
514 static void
515 keg_timeout(uma_keg_t keg)
516 {
517 
518 	KEG_LOCK(keg);
519 	/*
520 	 * Expand the keg hash table.
521 	 *
522 	 * This is done if the number of slabs is larger than the hash size.
523 	 * What I'm trying to do here is completely reduce collisions.  This
524 	 * may be a little aggressive.  Should I allow for two collisions max?
525 	 */
526 	if (keg->uk_flags & UMA_ZONE_HASH &&
527 	    keg->uk_pages / keg->uk_ppera >= keg->uk_hash.uh_hashsize) {
528 		struct uma_hash newhash;
529 		struct uma_hash oldhash;
530 		int ret;
531 
532 		/*
533 		 * This is so involved because allocating and freeing
534 		 * while the keg lock is held will lead to deadlock.
535 		 * I have to do everything in stages and check for
536 		 * races.
537 		 */
538 		newhash = keg->uk_hash;
539 		KEG_UNLOCK(keg);
540 		ret = hash_alloc(&newhash);
541 		KEG_LOCK(keg);
542 		if (ret) {
543 			if (hash_expand(&keg->uk_hash, &newhash)) {
544 				oldhash = keg->uk_hash;
545 				keg->uk_hash = newhash;
546 			} else
547 				oldhash = newhash;
548 
549 			KEG_UNLOCK(keg);
550 			hash_free(&oldhash);
551 			return;
552 		}
553 	}
554 	KEG_UNLOCK(keg);
555 }
556 
557 static void
558 zone_timeout(uma_zone_t zone)
559 {
560 
561 	zone_foreach_keg(zone, &keg_timeout);
562 }
563 
564 /*
565  * Allocate and zero fill the next sized hash table from the appropriate
566  * backing store.
567  *
568  * Arguments:
569  *	hash  A new hash structure with the old hash size in uh_hashsize
570  *
571  * Returns:
572  *	1 on success and 0 on failure.
573  */
574 static int
575 hash_alloc(struct uma_hash *hash)
576 {
577 	int oldsize;
578 	int alloc;
579 
580 	oldsize = hash->uh_hashsize;
581 
582 	/* We're just going to go to a power of two greater */
583 	if (oldsize)  {
584 		hash->uh_hashsize = oldsize * 2;
585 		alloc = sizeof(hash->uh_slab_hash[0]) * hash->uh_hashsize;
586 		hash->uh_slab_hash = (struct slabhead *)malloc(alloc,
587 		    M_UMAHASH, M_NOWAIT);
588 	} else {
589 		alloc = sizeof(hash->uh_slab_hash[0]) * UMA_HASH_SIZE_INIT;
590 		hash->uh_slab_hash = zone_alloc_item(hashzone, NULL,
591 		    UMA_ANYDOMAIN, M_WAITOK);
592 		hash->uh_hashsize = UMA_HASH_SIZE_INIT;
593 	}
594 	if (hash->uh_slab_hash) {
595 		bzero(hash->uh_slab_hash, alloc);
596 		hash->uh_hashmask = hash->uh_hashsize - 1;
597 		return (1);
598 	}
599 
600 	return (0);
601 }
602 
603 /*
604  * Expands the hash table for HASH zones.  This is done from zone_timeout
605  * to reduce collisions.  This must not be done in the regular allocation
606  * path, otherwise, we can recurse on the vm while allocating pages.
607  *
608  * Arguments:
609  *	oldhash  The hash you want to expand
610  *	newhash  The hash structure for the new table
611  *
612  * Returns:
613  *	Nothing
614  *
615  * Discussion:
616  */
617 static int
618 hash_expand(struct uma_hash *oldhash, struct uma_hash *newhash)
619 {
620 	uma_slab_t slab;
621 	int hval;
622 	int i;
623 
624 	if (!newhash->uh_slab_hash)
625 		return (0);
626 
627 	if (oldhash->uh_hashsize >= newhash->uh_hashsize)
628 		return (0);
629 
630 	/*
631 	 * I need to investigate hash algorithms for resizing without a
632 	 * full rehash.
633 	 */
634 
635 	for (i = 0; i < oldhash->uh_hashsize; i++)
636 		while (!SLIST_EMPTY(&oldhash->uh_slab_hash[i])) {
637 			slab = SLIST_FIRST(&oldhash->uh_slab_hash[i]);
638 			SLIST_REMOVE_HEAD(&oldhash->uh_slab_hash[i], us_hlink);
639 			hval = UMA_HASH(newhash, slab->us_data);
640 			SLIST_INSERT_HEAD(&newhash->uh_slab_hash[hval],
641 			    slab, us_hlink);
642 		}
643 
644 	return (1);
645 }
646 
647 /*
648  * Free the hash bucket to the appropriate backing store.
649  *
650  * Arguments:
651  *	slab_hash  The hash bucket we're freeing
652  *	hashsize   The number of entries in that hash bucket
653  *
654  * Returns:
655  *	Nothing
656  */
657 static void
658 hash_free(struct uma_hash *hash)
659 {
660 	if (hash->uh_slab_hash == NULL)
661 		return;
662 	if (hash->uh_hashsize == UMA_HASH_SIZE_INIT)
663 		zone_free_item(hashzone, hash->uh_slab_hash, NULL, SKIP_NONE);
664 	else
665 		free(hash->uh_slab_hash, M_UMAHASH);
666 }
667 
668 /*
669  * Frees all outstanding items in a bucket
670  *
671  * Arguments:
672  *	zone   The zone to free to, must be unlocked.
673  *	bucket The free/alloc bucket with items, cpu queue must be locked.
674  *
675  * Returns:
676  *	Nothing
677  */
678 
679 static void
680 bucket_drain(uma_zone_t zone, uma_bucket_t bucket)
681 {
682 	int i;
683 
684 	if (bucket == NULL)
685 		return;
686 
687 	if (zone->uz_fini)
688 		for (i = 0; i < bucket->ub_cnt; i++)
689 			zone->uz_fini(bucket->ub_bucket[i], zone->uz_size);
690 	zone->uz_release(zone->uz_arg, bucket->ub_bucket, bucket->ub_cnt);
691 	bucket->ub_cnt = 0;
692 }
693 
694 /*
695  * Drains the per cpu caches for a zone.
696  *
697  * NOTE: This may only be called while the zone is being turn down, and not
698  * during normal operation.  This is necessary in order that we do not have
699  * to migrate CPUs to drain the per-CPU caches.
700  *
701  * Arguments:
702  *	zone     The zone to drain, must be unlocked.
703  *
704  * Returns:
705  *	Nothing
706  */
707 static void
708 cache_drain(uma_zone_t zone)
709 {
710 	uma_cache_t cache;
711 	int cpu;
712 
713 	/*
714 	 * XXX: It is safe to not lock the per-CPU caches, because we're
715 	 * tearing down the zone anyway.  I.e., there will be no further use
716 	 * of the caches at this point.
717 	 *
718 	 * XXX: It would good to be able to assert that the zone is being
719 	 * torn down to prevent improper use of cache_drain().
720 	 *
721 	 * XXX: We lock the zone before passing into bucket_cache_drain() as
722 	 * it is used elsewhere.  Should the tear-down path be made special
723 	 * there in some form?
724 	 */
725 	CPU_FOREACH(cpu) {
726 		cache = &zone->uz_cpu[cpu];
727 		bucket_drain(zone, cache->uc_allocbucket);
728 		bucket_drain(zone, cache->uc_freebucket);
729 		if (cache->uc_allocbucket != NULL)
730 			bucket_free(zone, cache->uc_allocbucket, NULL);
731 		if (cache->uc_freebucket != NULL)
732 			bucket_free(zone, cache->uc_freebucket, NULL);
733 		cache->uc_allocbucket = cache->uc_freebucket = NULL;
734 	}
735 	ZONE_LOCK(zone);
736 	bucket_cache_drain(zone);
737 	ZONE_UNLOCK(zone);
738 }
739 
740 static void
741 cache_shrink(uma_zone_t zone)
742 {
743 
744 	if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
745 		return;
746 
747 	ZONE_LOCK(zone);
748 	zone->uz_count = (zone->uz_count_min + zone->uz_count) / 2;
749 	ZONE_UNLOCK(zone);
750 }
751 
752 static void
753 cache_drain_safe_cpu(uma_zone_t zone)
754 {
755 	uma_cache_t cache;
756 	uma_bucket_t b1, b2;
757 	int domain;
758 
759 	if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
760 		return;
761 
762 	b1 = b2 = NULL;
763 	ZONE_LOCK(zone);
764 	critical_enter();
765 	if (zone->uz_flags & UMA_ZONE_NUMA)
766 		domain = PCPU_GET(domain);
767 	else
768 		domain = 0;
769 	cache = &zone->uz_cpu[curcpu];
770 	if (cache->uc_allocbucket) {
771 		if (cache->uc_allocbucket->ub_cnt != 0)
772 			LIST_INSERT_HEAD(&zone->uz_domain[domain].uzd_buckets,
773 			    cache->uc_allocbucket, ub_link);
774 		else
775 			b1 = cache->uc_allocbucket;
776 		cache->uc_allocbucket = NULL;
777 	}
778 	if (cache->uc_freebucket) {
779 		if (cache->uc_freebucket->ub_cnt != 0)
780 			LIST_INSERT_HEAD(&zone->uz_domain[domain].uzd_buckets,
781 			    cache->uc_freebucket, ub_link);
782 		else
783 			b2 = cache->uc_freebucket;
784 		cache->uc_freebucket = NULL;
785 	}
786 	critical_exit();
787 	ZONE_UNLOCK(zone);
788 	if (b1)
789 		bucket_free(zone, b1, NULL);
790 	if (b2)
791 		bucket_free(zone, b2, NULL);
792 }
793 
794 /*
795  * Safely drain per-CPU caches of a zone(s) to alloc bucket.
796  * This is an expensive call because it needs to bind to all CPUs
797  * one by one and enter a critical section on each of them in order
798  * to safely access their cache buckets.
799  * Zone lock must not be held on call this function.
800  */
801 static void
802 cache_drain_safe(uma_zone_t zone)
803 {
804 	int cpu;
805 
806 	/*
807 	 * Polite bucket sizes shrinking was not enouth, shrink aggressively.
808 	 */
809 	if (zone)
810 		cache_shrink(zone);
811 	else
812 		zone_foreach(cache_shrink);
813 
814 	CPU_FOREACH(cpu) {
815 		thread_lock(curthread);
816 		sched_bind(curthread, cpu);
817 		thread_unlock(curthread);
818 
819 		if (zone)
820 			cache_drain_safe_cpu(zone);
821 		else
822 			zone_foreach(cache_drain_safe_cpu);
823 	}
824 	thread_lock(curthread);
825 	sched_unbind(curthread);
826 	thread_unlock(curthread);
827 }
828 
829 /*
830  * Drain the cached buckets from a zone.  Expects a locked zone on entry.
831  */
832 static void
833 bucket_cache_drain(uma_zone_t zone)
834 {
835 	uma_zone_domain_t zdom;
836 	uma_bucket_t bucket;
837 	int i;
838 
839 	/*
840 	 * Drain the bucket queues and free the buckets.
841 	 */
842 	for (i = 0; i < vm_ndomains; i++) {
843 		zdom = &zone->uz_domain[i];
844 		while ((bucket = LIST_FIRST(&zdom->uzd_buckets)) != NULL) {
845 			LIST_REMOVE(bucket, ub_link);
846 			ZONE_UNLOCK(zone);
847 			bucket_drain(zone, bucket);
848 			bucket_free(zone, bucket, NULL);
849 			ZONE_LOCK(zone);
850 		}
851 	}
852 
853 	/*
854 	 * Shrink further bucket sizes.  Price of single zone lock collision
855 	 * is probably lower then price of global cache drain.
856 	 */
857 	if (zone->uz_count > zone->uz_count_min)
858 		zone->uz_count--;
859 }
860 
861 static void
862 keg_free_slab(uma_keg_t keg, uma_slab_t slab, int start)
863 {
864 	uint8_t *mem;
865 	int i;
866 	uint8_t flags;
867 
868 	CTR4(KTR_UMA, "keg_free_slab keg %s(%p) slab %p, returning %d bytes",
869 	    keg->uk_name, keg, slab, PAGE_SIZE * keg->uk_ppera);
870 
871 	mem = slab->us_data;
872 	flags = slab->us_flags;
873 	i = start;
874 	if (keg->uk_fini != NULL) {
875 		for (i--; i > -1; i--)
876 #ifdef INVARIANTS
877 		/*
878 		 * trash_fini implies that dtor was trash_dtor. trash_fini
879 		 * would check that memory hasn't been modified since free,
880 		 * which executed trash_dtor.
881 		 * That's why we need to run uma_dbg_kskip() check here,
882 		 * albeit we don't make skip check for other init/fini
883 		 * invocations.
884 		 */
885 		if (!uma_dbg_kskip(keg, slab->us_data + (keg->uk_rsize * i)) ||
886 		    keg->uk_fini != trash_fini)
887 #endif
888 			keg->uk_fini(slab->us_data + (keg->uk_rsize * i),
889 			    keg->uk_size);
890 	}
891 	if (keg->uk_flags & UMA_ZONE_OFFPAGE)
892 		zone_free_item(keg->uk_slabzone, slab, NULL, SKIP_NONE);
893 	keg->uk_freef(mem, PAGE_SIZE * keg->uk_ppera, flags);
894 	uma_total_dec(PAGE_SIZE * keg->uk_ppera);
895 }
896 
897 /*
898  * Frees pages from a keg back to the system.  This is done on demand from
899  * the pageout daemon.
900  *
901  * Returns nothing.
902  */
903 static void
904 keg_drain(uma_keg_t keg)
905 {
906 	struct slabhead freeslabs = { 0 };
907 	uma_domain_t dom;
908 	uma_slab_t slab, tmp;
909 	int i;
910 
911 	/*
912 	 * We don't want to take pages from statically allocated kegs at this
913 	 * time
914 	 */
915 	if (keg->uk_flags & UMA_ZONE_NOFREE || keg->uk_freef == NULL)
916 		return;
917 
918 	CTR3(KTR_UMA, "keg_drain %s(%p) free items: %u",
919 	    keg->uk_name, keg, keg->uk_free);
920 	KEG_LOCK(keg);
921 	if (keg->uk_free == 0)
922 		goto finished;
923 
924 	for (i = 0; i < vm_ndomains; i++) {
925 		dom = &keg->uk_domain[i];
926 		LIST_FOREACH_SAFE(slab, &dom->ud_free_slab, us_link, tmp) {
927 			/* We have nowhere to free these to. */
928 			if (slab->us_flags & UMA_SLAB_BOOT)
929 				continue;
930 
931 			LIST_REMOVE(slab, us_link);
932 			keg->uk_pages -= keg->uk_ppera;
933 			keg->uk_free -= keg->uk_ipers;
934 
935 			if (keg->uk_flags & UMA_ZONE_HASH)
936 				UMA_HASH_REMOVE(&keg->uk_hash, slab,
937 				    slab->us_data);
938 
939 			SLIST_INSERT_HEAD(&freeslabs, slab, us_hlink);
940 		}
941 	}
942 
943 finished:
944 	KEG_UNLOCK(keg);
945 
946 	while ((slab = SLIST_FIRST(&freeslabs)) != NULL) {
947 		SLIST_REMOVE(&freeslabs, slab, uma_slab, us_hlink);
948 		keg_free_slab(keg, slab, keg->uk_ipers);
949 	}
950 }
951 
952 static void
953 zone_drain_wait(uma_zone_t zone, int waitok)
954 {
955 
956 	/*
957 	 * Set draining to interlock with zone_dtor() so we can release our
958 	 * locks as we go.  Only dtor() should do a WAITOK call since it
959 	 * is the only call that knows the structure will still be available
960 	 * when it wakes up.
961 	 */
962 	ZONE_LOCK(zone);
963 	while (zone->uz_flags & UMA_ZFLAG_DRAINING) {
964 		if (waitok == M_NOWAIT)
965 			goto out;
966 		msleep(zone, zone->uz_lockptr, PVM, "zonedrain", 1);
967 	}
968 	zone->uz_flags |= UMA_ZFLAG_DRAINING;
969 	bucket_cache_drain(zone);
970 	ZONE_UNLOCK(zone);
971 	/*
972 	 * The DRAINING flag protects us from being freed while
973 	 * we're running.  Normally the uma_rwlock would protect us but we
974 	 * must be able to release and acquire the right lock for each keg.
975 	 */
976 	zone_foreach_keg(zone, &keg_drain);
977 	ZONE_LOCK(zone);
978 	zone->uz_flags &= ~UMA_ZFLAG_DRAINING;
979 	wakeup(zone);
980 out:
981 	ZONE_UNLOCK(zone);
982 }
983 
984 void
985 zone_drain(uma_zone_t zone)
986 {
987 
988 	zone_drain_wait(zone, M_NOWAIT);
989 }
990 
991 /*
992  * Allocate a new slab for a keg.  This does not insert the slab onto a list.
993  *
994  * Arguments:
995  *	wait  Shall we wait?
996  *
997  * Returns:
998  *	The slab that was allocated or NULL if there is no memory and the
999  *	caller specified M_NOWAIT.
1000  */
1001 static uma_slab_t
1002 keg_alloc_slab(uma_keg_t keg, uma_zone_t zone, int domain, int wait)
1003 {
1004 	uma_alloc allocf;
1005 	uma_slab_t slab;
1006 	unsigned long size;
1007 	uint8_t *mem;
1008 	uint8_t flags;
1009 	int i;
1010 
1011 	KASSERT(domain >= 0 && domain < vm_ndomains,
1012 	    ("keg_alloc_slab: domain %d out of range", domain));
1013 	mtx_assert(&keg->uk_lock, MA_OWNED);
1014 	slab = NULL;
1015 	mem = NULL;
1016 
1017 	allocf = keg->uk_allocf;
1018 	KEG_UNLOCK(keg);
1019 	size = keg->uk_ppera * PAGE_SIZE;
1020 
1021 	if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
1022 		slab = zone_alloc_item(keg->uk_slabzone, NULL, domain, wait);
1023 		if (slab == NULL)
1024 			goto out;
1025 	}
1026 
1027 	/*
1028 	 * This reproduces the old vm_zone behavior of zero filling pages the
1029 	 * first time they are added to a zone.
1030 	 *
1031 	 * Malloced items are zeroed in uma_zalloc.
1032 	 */
1033 
1034 	if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
1035 		wait |= M_ZERO;
1036 	else
1037 		wait &= ~M_ZERO;
1038 
1039 	if (keg->uk_flags & UMA_ZONE_NODUMP)
1040 		wait |= M_NODUMP;
1041 
1042 	/* zone is passed for legacy reasons. */
1043 	mem = allocf(zone, size, domain, &flags, wait);
1044 	if (mem == NULL) {
1045 		if (keg->uk_flags & UMA_ZONE_OFFPAGE)
1046 			zone_free_item(keg->uk_slabzone, slab, NULL, SKIP_NONE);
1047 		slab = NULL;
1048 		goto out;
1049 	}
1050 	uma_total_inc(size);
1051 
1052 	/* Point the slab into the allocated memory */
1053 	if (!(keg->uk_flags & UMA_ZONE_OFFPAGE))
1054 		slab = (uma_slab_t )(mem + keg->uk_pgoff);
1055 
1056 	if (keg->uk_flags & UMA_ZONE_VTOSLAB)
1057 		for (i = 0; i < keg->uk_ppera; i++)
1058 			vsetslab((vm_offset_t)mem + (i * PAGE_SIZE), slab);
1059 
1060 	slab->us_keg = keg;
1061 	slab->us_data = mem;
1062 	slab->us_freecount = keg->uk_ipers;
1063 	slab->us_flags = flags;
1064 	slab->us_domain = domain;
1065 	BIT_FILL(SLAB_SETSIZE, &slab->us_free);
1066 #ifdef INVARIANTS
1067 	BIT_ZERO(SLAB_SETSIZE, &slab->us_debugfree);
1068 #endif
1069 
1070 	if (keg->uk_init != NULL) {
1071 		for (i = 0; i < keg->uk_ipers; i++)
1072 			if (keg->uk_init(slab->us_data + (keg->uk_rsize * i),
1073 			    keg->uk_size, wait) != 0)
1074 				break;
1075 		if (i != keg->uk_ipers) {
1076 			keg_free_slab(keg, slab, i);
1077 			slab = NULL;
1078 			goto out;
1079 		}
1080 	}
1081 out:
1082 	KEG_LOCK(keg);
1083 
1084 	CTR3(KTR_UMA, "keg_alloc_slab: allocated slab %p for %s(%p)",
1085 	    slab, keg->uk_name, keg);
1086 
1087 	if (slab != NULL) {
1088 		if (keg->uk_flags & UMA_ZONE_HASH)
1089 			UMA_HASH_INSERT(&keg->uk_hash, slab, mem);
1090 
1091 		keg->uk_pages += keg->uk_ppera;
1092 		keg->uk_free += keg->uk_ipers;
1093 	}
1094 
1095 	return (slab);
1096 }
1097 
1098 /*
1099  * This function is intended to be used early on in place of page_alloc() so
1100  * that we may use the boot time page cache to satisfy allocations before
1101  * the VM is ready.
1102  */
1103 static void *
1104 startup_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
1105     int wait)
1106 {
1107 	uma_keg_t keg;
1108 	void *mem;
1109 	int pages;
1110 
1111 	keg = zone_first_keg(zone);
1112 
1113 	/*
1114 	 * If we are in BOOT_BUCKETS or higher, than switch to real
1115 	 * allocator.  Zones with page sized slabs switch at BOOT_PAGEALLOC.
1116 	 */
1117 	switch (booted) {
1118 		case BOOT_COLD:
1119 		case BOOT_STRAPPED:
1120 			break;
1121 		case BOOT_PAGEALLOC:
1122 			if (keg->uk_ppera > 1)
1123 				break;
1124 		case BOOT_BUCKETS:
1125 		case BOOT_RUNNING:
1126 #ifdef UMA_MD_SMALL_ALLOC
1127 			keg->uk_allocf = (keg->uk_ppera > 1) ?
1128 			    page_alloc : uma_small_alloc;
1129 #else
1130 			keg->uk_allocf = page_alloc;
1131 #endif
1132 			return keg->uk_allocf(zone, bytes, domain, pflag, wait);
1133 	}
1134 
1135 	/*
1136 	 * Check our small startup cache to see if it has pages remaining.
1137 	 */
1138 	pages = howmany(bytes, PAGE_SIZE);
1139 	KASSERT(pages > 0, ("%s can't reserve 0 pages", __func__));
1140 	if (pages > boot_pages)
1141 		panic("UMA zone \"%s\": Increase vm.boot_pages", zone->uz_name);
1142 #ifdef DIAGNOSTIC
1143 	printf("%s from \"%s\", %d boot pages left\n", __func__, zone->uz_name,
1144 	    boot_pages);
1145 #endif
1146 	mem = bootmem;
1147 	boot_pages -= pages;
1148 	bootmem += pages * PAGE_SIZE;
1149 	*pflag = UMA_SLAB_BOOT;
1150 
1151 	return (mem);
1152 }
1153 
1154 /*
1155  * Allocates a number of pages from the system
1156  *
1157  * Arguments:
1158  *	bytes  The number of bytes requested
1159  *	wait  Shall we wait?
1160  *
1161  * Returns:
1162  *	A pointer to the alloced memory or possibly
1163  *	NULL if M_NOWAIT is set.
1164  */
1165 static void *
1166 page_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
1167     int wait)
1168 {
1169 	void *p;	/* Returned page */
1170 
1171 	*pflag = UMA_SLAB_KERNEL;
1172 	p = (void *) kmem_malloc_domain(kernel_arena, domain, bytes, wait);
1173 
1174 	return (p);
1175 }
1176 
1177 static void *
1178 pcpu_page_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
1179     int wait)
1180 {
1181 	struct pglist alloctail;
1182 	vm_offset_t addr, zkva;
1183 	int cpu, flags;
1184 	vm_page_t p, p_next;
1185 #ifdef NUMA
1186 	struct pcpu *pc;
1187 #endif
1188 
1189 	TAILQ_INIT(&alloctail);
1190 	MPASS(bytes == (mp_maxid+1)*PAGE_SIZE);
1191 	*pflag = UMA_SLAB_KERNEL;
1192 
1193 	flags = VM_ALLOC_SYSTEM | VM_ALLOC_WIRED | VM_ALLOC_NOOBJ |
1194 		((wait & M_WAITOK) != 0 ? VM_ALLOC_WAITOK :
1195 		 VM_ALLOC_NOWAIT);
1196 	for (cpu = 0; cpu <= mp_maxid; cpu++) {
1197 		if (CPU_ABSENT(cpu)) {
1198 			p = vm_page_alloc(NULL, 0, flags);
1199 		} else {
1200 #ifndef NUMA
1201 			p = vm_page_alloc(NULL, 0, flags);
1202 #else
1203 			pc = pcpu_find(cpu);
1204 			p = vm_page_alloc_domain(NULL, 0, pc->pc_domain, flags);
1205 			if (__predict_false(p == NULL))
1206 				p = vm_page_alloc(NULL, 0, flags);
1207 #endif
1208 		}
1209 		if (__predict_false(p == NULL))
1210 			goto fail;
1211 		TAILQ_INSERT_TAIL(&alloctail, p, listq);
1212 	}
1213 	if ((addr = kva_alloc(bytes)) == 0)
1214 		goto fail;
1215 	zkva = addr;
1216 	TAILQ_FOREACH(p, &alloctail, listq) {
1217 		pmap_qenter(zkva, &p, 1);
1218 		zkva += PAGE_SIZE;
1219 	}
1220 	return ((void*)addr);
1221  fail:
1222 	TAILQ_FOREACH_SAFE(p, &alloctail, listq, p_next) {
1223 		vm_page_unwire(p, PQ_NONE);
1224 		vm_page_free(p);
1225 	}
1226 	return (NULL);
1227 }
1228 
1229 /*
1230  * Allocates a number of pages from within an object
1231  *
1232  * Arguments:
1233  *	bytes  The number of bytes requested
1234  *	wait   Shall we wait?
1235  *
1236  * Returns:
1237  *	A pointer to the alloced memory or possibly
1238  *	NULL if M_NOWAIT is set.
1239  */
1240 static void *
1241 noobj_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *flags,
1242     int wait)
1243 {
1244 	TAILQ_HEAD(, vm_page) alloctail;
1245 	u_long npages;
1246 	vm_offset_t retkva, zkva;
1247 	vm_page_t p, p_next;
1248 	uma_keg_t keg;
1249 
1250 	TAILQ_INIT(&alloctail);
1251 	keg = zone_first_keg(zone);
1252 
1253 	npages = howmany(bytes, PAGE_SIZE);
1254 	while (npages > 0) {
1255 		p = vm_page_alloc_domain(NULL, 0, domain, VM_ALLOC_INTERRUPT |
1256 		    VM_ALLOC_WIRED | VM_ALLOC_NOOBJ |
1257 		    ((wait & M_WAITOK) != 0 ? VM_ALLOC_WAITOK :
1258 		    VM_ALLOC_NOWAIT));
1259 		if (p != NULL) {
1260 			/*
1261 			 * Since the page does not belong to an object, its
1262 			 * listq is unused.
1263 			 */
1264 			TAILQ_INSERT_TAIL(&alloctail, p, listq);
1265 			npages--;
1266 			continue;
1267 		}
1268 		/*
1269 		 * Page allocation failed, free intermediate pages and
1270 		 * exit.
1271 		 */
1272 		TAILQ_FOREACH_SAFE(p, &alloctail, listq, p_next) {
1273 			vm_page_unwire(p, PQ_NONE);
1274 			vm_page_free(p);
1275 		}
1276 		return (NULL);
1277 	}
1278 	*flags = UMA_SLAB_PRIV;
1279 	zkva = keg->uk_kva +
1280 	    atomic_fetchadd_long(&keg->uk_offset, round_page(bytes));
1281 	retkva = zkva;
1282 	TAILQ_FOREACH(p, &alloctail, listq) {
1283 		pmap_qenter(zkva, &p, 1);
1284 		zkva += PAGE_SIZE;
1285 	}
1286 
1287 	return ((void *)retkva);
1288 }
1289 
1290 /*
1291  * Frees a number of pages to the system
1292  *
1293  * Arguments:
1294  *	mem   A pointer to the memory to be freed
1295  *	size  The size of the memory being freed
1296  *	flags The original p->us_flags field
1297  *
1298  * Returns:
1299  *	Nothing
1300  */
1301 static void
1302 page_free(void *mem, vm_size_t size, uint8_t flags)
1303 {
1304 	struct vmem *vmem;
1305 
1306 	if (flags & UMA_SLAB_KERNEL)
1307 		vmem = kernel_arena;
1308 	else
1309 		panic("UMA: page_free used with invalid flags %x", flags);
1310 
1311 	kmem_free(vmem, (vm_offset_t)mem, size);
1312 }
1313 
1314 /*
1315  * Frees pcpu zone allocations
1316  *
1317  * Arguments:
1318  *	mem   A pointer to the memory to be freed
1319  *	size  The size of the memory being freed
1320  *	flags The original p->us_flags field
1321  *
1322  * Returns:
1323  *	Nothing
1324  */
1325 static void
1326 pcpu_page_free(void *mem, vm_size_t size, uint8_t flags)
1327 {
1328 	vm_offset_t sva, curva;
1329 	vm_paddr_t paddr;
1330 	vm_page_t m;
1331 
1332 	MPASS(size == (mp_maxid+1)*PAGE_SIZE);
1333 	sva = (vm_offset_t)mem;
1334 	for (curva = sva; curva < sva + size; curva += PAGE_SIZE) {
1335 		paddr = pmap_kextract(curva);
1336 		m = PHYS_TO_VM_PAGE(paddr);
1337 		vm_page_unwire(m, PQ_NONE);
1338 		vm_page_free(m);
1339 	}
1340 	pmap_qremove(sva, size >> PAGE_SHIFT);
1341 	kva_free(sva, size);
1342 }
1343 
1344 
1345 /*
1346  * Zero fill initializer
1347  *
1348  * Arguments/Returns follow uma_init specifications
1349  */
1350 static int
1351 zero_init(void *mem, int size, int flags)
1352 {
1353 	bzero(mem, size);
1354 	return (0);
1355 }
1356 
1357 /*
1358  * Finish creating a small uma keg.  This calculates ipers, and the keg size.
1359  *
1360  * Arguments
1361  *	keg  The zone we should initialize
1362  *
1363  * Returns
1364  *	Nothing
1365  */
1366 static void
1367 keg_small_init(uma_keg_t keg)
1368 {
1369 	u_int rsize;
1370 	u_int memused;
1371 	u_int wastedspace;
1372 	u_int shsize;
1373 	u_int slabsize;
1374 
1375 	if (keg->uk_flags & UMA_ZONE_PCPU) {
1376 		u_int ncpus = (mp_maxid + 1) ? (mp_maxid + 1) : MAXCPU;
1377 
1378 		slabsize = UMA_PCPU_ALLOC_SIZE;
1379 		keg->uk_ppera = ncpus;
1380 	} else {
1381 		slabsize = UMA_SLAB_SIZE;
1382 		keg->uk_ppera = 1;
1383 	}
1384 
1385 	/*
1386 	 * Calculate the size of each allocation (rsize) according to
1387 	 * alignment.  If the requested size is smaller than we have
1388 	 * allocation bits for we round it up.
1389 	 */
1390 	rsize = keg->uk_size;
1391 	if (rsize < slabsize / SLAB_SETSIZE)
1392 		rsize = slabsize / SLAB_SETSIZE;
1393 	if (rsize & keg->uk_align)
1394 		rsize = (rsize & ~keg->uk_align) + (keg->uk_align + 1);
1395 	keg->uk_rsize = rsize;
1396 
1397 	KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0 ||
1398 	    keg->uk_rsize < UMA_PCPU_ALLOC_SIZE,
1399 	    ("%s: size %u too large", __func__, keg->uk_rsize));
1400 
1401 	if (keg->uk_flags & UMA_ZONE_OFFPAGE)
1402 		shsize = 0;
1403 	else
1404 		shsize = sizeof(struct uma_slab);
1405 
1406 	if (rsize <= slabsize - shsize)
1407 		keg->uk_ipers = (slabsize - shsize) / rsize;
1408 	else {
1409 		/* Handle special case when we have 1 item per slab, so
1410 		 * alignment requirement can be relaxed. */
1411 		KASSERT(keg->uk_size <= slabsize - shsize,
1412 		    ("%s: size %u greater than slab", __func__, keg->uk_size));
1413 		keg->uk_ipers = 1;
1414 	}
1415 	KASSERT(keg->uk_ipers > 0 && keg->uk_ipers <= SLAB_SETSIZE,
1416 	    ("%s: keg->uk_ipers %u", __func__, keg->uk_ipers));
1417 
1418 	memused = keg->uk_ipers * rsize + shsize;
1419 	wastedspace = slabsize - memused;
1420 
1421 	/*
1422 	 * We can't do OFFPAGE if we're internal or if we've been
1423 	 * asked to not go to the VM for buckets.  If we do this we
1424 	 * may end up going to the VM  for slabs which we do not
1425 	 * want to do if we're UMA_ZFLAG_CACHEONLY as a result
1426 	 * of UMA_ZONE_VM, which clearly forbids it.
1427 	 */
1428 	if ((keg->uk_flags & UMA_ZFLAG_INTERNAL) ||
1429 	    (keg->uk_flags & UMA_ZFLAG_CACHEONLY))
1430 		return;
1431 
1432 	/*
1433 	 * See if using an OFFPAGE slab will limit our waste.  Only do
1434 	 * this if it permits more items per-slab.
1435 	 *
1436 	 * XXX We could try growing slabsize to limit max waste as well.
1437 	 * Historically this was not done because the VM could not
1438 	 * efficiently handle contiguous allocations.
1439 	 */
1440 	if ((wastedspace >= slabsize / UMA_MAX_WASTE) &&
1441 	    (keg->uk_ipers < (slabsize / keg->uk_rsize))) {
1442 		keg->uk_ipers = slabsize / keg->uk_rsize;
1443 		KASSERT(keg->uk_ipers > 0 && keg->uk_ipers <= SLAB_SETSIZE,
1444 		    ("%s: keg->uk_ipers %u", __func__, keg->uk_ipers));
1445 		CTR6(KTR_UMA, "UMA decided we need offpage slab headers for "
1446 		    "keg: %s(%p), calculated wastedspace = %d, "
1447 		    "maximum wasted space allowed = %d, "
1448 		    "calculated ipers = %d, "
1449 		    "new wasted space = %d\n", keg->uk_name, keg, wastedspace,
1450 		    slabsize / UMA_MAX_WASTE, keg->uk_ipers,
1451 		    slabsize - keg->uk_ipers * keg->uk_rsize);
1452 		keg->uk_flags |= UMA_ZONE_OFFPAGE;
1453 	}
1454 
1455 	if ((keg->uk_flags & UMA_ZONE_OFFPAGE) &&
1456 	    (keg->uk_flags & UMA_ZONE_VTOSLAB) == 0)
1457 		keg->uk_flags |= UMA_ZONE_HASH;
1458 }
1459 
1460 /*
1461  * Finish creating a large (> UMA_SLAB_SIZE) uma kegs.  Just give in and do
1462  * OFFPAGE for now.  When I can allow for more dynamic slab sizes this will be
1463  * more complicated.
1464  *
1465  * Arguments
1466  *	keg  The keg we should initialize
1467  *
1468  * Returns
1469  *	Nothing
1470  */
1471 static void
1472 keg_large_init(uma_keg_t keg)
1473 {
1474 	u_int shsize;
1475 
1476 	KASSERT(keg != NULL, ("Keg is null in keg_large_init"));
1477 	KASSERT((keg->uk_flags & UMA_ZFLAG_CACHEONLY) == 0,
1478 	    ("keg_large_init: Cannot large-init a UMA_ZFLAG_CACHEONLY keg"));
1479 	KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0,
1480 	    ("%s: Cannot large-init a UMA_ZONE_PCPU keg", __func__));
1481 
1482 	keg->uk_ppera = howmany(keg->uk_size, PAGE_SIZE);
1483 	keg->uk_ipers = 1;
1484 	keg->uk_rsize = keg->uk_size;
1485 
1486 	/* Check whether we have enough space to not do OFFPAGE. */
1487 	if ((keg->uk_flags & UMA_ZONE_OFFPAGE) == 0) {
1488 		shsize = sizeof(struct uma_slab);
1489 		if (shsize & UMA_ALIGN_PTR)
1490 			shsize = (shsize & ~UMA_ALIGN_PTR) +
1491 			    (UMA_ALIGN_PTR + 1);
1492 
1493 		if (PAGE_SIZE * keg->uk_ppera - keg->uk_rsize < shsize) {
1494 			/*
1495 			 * We can't do OFFPAGE if we're internal, in which case
1496 			 * we need an extra page per allocation to contain the
1497 			 * slab header.
1498 			 */
1499 			if ((keg->uk_flags & UMA_ZFLAG_INTERNAL) == 0)
1500 				keg->uk_flags |= UMA_ZONE_OFFPAGE;
1501 			else
1502 				keg->uk_ppera++;
1503 		}
1504 	}
1505 
1506 	if ((keg->uk_flags & UMA_ZONE_OFFPAGE) &&
1507 	    (keg->uk_flags & UMA_ZONE_VTOSLAB) == 0)
1508 		keg->uk_flags |= UMA_ZONE_HASH;
1509 }
1510 
1511 static void
1512 keg_cachespread_init(uma_keg_t keg)
1513 {
1514 	int alignsize;
1515 	int trailer;
1516 	int pages;
1517 	int rsize;
1518 
1519 	KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0,
1520 	    ("%s: Cannot cachespread-init a UMA_ZONE_PCPU keg", __func__));
1521 
1522 	alignsize = keg->uk_align + 1;
1523 	rsize = keg->uk_size;
1524 	/*
1525 	 * We want one item to start on every align boundary in a page.  To
1526 	 * do this we will span pages.  We will also extend the item by the
1527 	 * size of align if it is an even multiple of align.  Otherwise, it
1528 	 * would fall on the same boundary every time.
1529 	 */
1530 	if (rsize & keg->uk_align)
1531 		rsize = (rsize & ~keg->uk_align) + alignsize;
1532 	if ((rsize & alignsize) == 0)
1533 		rsize += alignsize;
1534 	trailer = rsize - keg->uk_size;
1535 	pages = (rsize * (PAGE_SIZE / alignsize)) / PAGE_SIZE;
1536 	pages = MIN(pages, (128 * 1024) / PAGE_SIZE);
1537 	keg->uk_rsize = rsize;
1538 	keg->uk_ppera = pages;
1539 	keg->uk_ipers = ((pages * PAGE_SIZE) + trailer) / rsize;
1540 	keg->uk_flags |= UMA_ZONE_OFFPAGE | UMA_ZONE_VTOSLAB;
1541 	KASSERT(keg->uk_ipers <= SLAB_SETSIZE,
1542 	    ("%s: keg->uk_ipers too high(%d) increase max_ipers", __func__,
1543 	    keg->uk_ipers));
1544 }
1545 
1546 /*
1547  * Keg header ctor.  This initializes all fields, locks, etc.  And inserts
1548  * the keg onto the global keg list.
1549  *
1550  * Arguments/Returns follow uma_ctor specifications
1551  *	udata  Actually uma_kctor_args
1552  */
1553 static int
1554 keg_ctor(void *mem, int size, void *udata, int flags)
1555 {
1556 	struct uma_kctor_args *arg = udata;
1557 	uma_keg_t keg = mem;
1558 	uma_zone_t zone;
1559 
1560 	bzero(keg, size);
1561 	keg->uk_size = arg->size;
1562 	keg->uk_init = arg->uminit;
1563 	keg->uk_fini = arg->fini;
1564 	keg->uk_align = arg->align;
1565 	keg->uk_cursor = 0;
1566 	keg->uk_free = 0;
1567 	keg->uk_reserve = 0;
1568 	keg->uk_pages = 0;
1569 	keg->uk_flags = arg->flags;
1570 	keg->uk_slabzone = NULL;
1571 
1572 	/*
1573 	 * The master zone is passed to us at keg-creation time.
1574 	 */
1575 	zone = arg->zone;
1576 	keg->uk_name = zone->uz_name;
1577 
1578 	if (arg->flags & UMA_ZONE_VM)
1579 		keg->uk_flags |= UMA_ZFLAG_CACHEONLY;
1580 
1581 	if (arg->flags & UMA_ZONE_ZINIT)
1582 		keg->uk_init = zero_init;
1583 
1584 	if (arg->flags & UMA_ZONE_MALLOC)
1585 		keg->uk_flags |= UMA_ZONE_VTOSLAB;
1586 
1587 	if (arg->flags & UMA_ZONE_PCPU)
1588 #ifdef SMP
1589 		keg->uk_flags |= UMA_ZONE_OFFPAGE;
1590 #else
1591 		keg->uk_flags &= ~UMA_ZONE_PCPU;
1592 #endif
1593 
1594 	if (keg->uk_flags & UMA_ZONE_CACHESPREAD) {
1595 		keg_cachespread_init(keg);
1596 	} else {
1597 		if (keg->uk_size > UMA_SLAB_SPACE)
1598 			keg_large_init(keg);
1599 		else
1600 			keg_small_init(keg);
1601 	}
1602 
1603 	if (keg->uk_flags & UMA_ZONE_OFFPAGE)
1604 		keg->uk_slabzone = slabzone;
1605 
1606 	/*
1607 	 * If we haven't booted yet we need allocations to go through the
1608 	 * startup cache until the vm is ready.
1609 	 */
1610 	if (booted < BOOT_PAGEALLOC)
1611 		keg->uk_allocf = startup_alloc;
1612 #ifdef UMA_MD_SMALL_ALLOC
1613 	else if (keg->uk_ppera == 1)
1614 		keg->uk_allocf = uma_small_alloc;
1615 #endif
1616 	else if (keg->uk_flags & UMA_ZONE_PCPU)
1617 		keg->uk_allocf = pcpu_page_alloc;
1618 	else
1619 		keg->uk_allocf = page_alloc;
1620 #ifdef UMA_MD_SMALL_ALLOC
1621 	if (keg->uk_ppera == 1)
1622 		keg->uk_freef = uma_small_free;
1623 	else
1624 #endif
1625 	if (keg->uk_flags & UMA_ZONE_PCPU)
1626 		keg->uk_freef = pcpu_page_free;
1627 	else
1628 		keg->uk_freef = page_free;
1629 
1630 	/*
1631 	 * Initialize keg's lock
1632 	 */
1633 	KEG_LOCK_INIT(keg, (arg->flags & UMA_ZONE_MTXCLASS));
1634 
1635 	/*
1636 	 * If we're putting the slab header in the actual page we need to
1637 	 * figure out where in each page it goes.  This calculates a right
1638 	 * justified offset into the memory on an ALIGN_PTR boundary.
1639 	 */
1640 	if (!(keg->uk_flags & UMA_ZONE_OFFPAGE)) {
1641 		u_int totsize;
1642 
1643 		/* Size of the slab struct and free list */
1644 		totsize = sizeof(struct uma_slab);
1645 
1646 		if (totsize & UMA_ALIGN_PTR)
1647 			totsize = (totsize & ~UMA_ALIGN_PTR) +
1648 			    (UMA_ALIGN_PTR + 1);
1649 		keg->uk_pgoff = (PAGE_SIZE * keg->uk_ppera) - totsize;
1650 
1651 		/*
1652 		 * The only way the following is possible is if with our
1653 		 * UMA_ALIGN_PTR adjustments we are now bigger than
1654 		 * UMA_SLAB_SIZE.  I haven't checked whether this is
1655 		 * mathematically possible for all cases, so we make
1656 		 * sure here anyway.
1657 		 */
1658 		totsize = keg->uk_pgoff + sizeof(struct uma_slab);
1659 		if (totsize > PAGE_SIZE * keg->uk_ppera) {
1660 			printf("zone %s ipers %d rsize %d size %d\n",
1661 			    zone->uz_name, keg->uk_ipers, keg->uk_rsize,
1662 			    keg->uk_size);
1663 			panic("UMA slab won't fit.");
1664 		}
1665 	}
1666 
1667 	if (keg->uk_flags & UMA_ZONE_HASH)
1668 		hash_alloc(&keg->uk_hash);
1669 
1670 	CTR5(KTR_UMA, "keg_ctor %p zone %s(%p) out %d free %d\n",
1671 	    keg, zone->uz_name, zone,
1672 	    (keg->uk_pages / keg->uk_ppera) * keg->uk_ipers - keg->uk_free,
1673 	    keg->uk_free);
1674 
1675 	LIST_INSERT_HEAD(&keg->uk_zones, zone, uz_link);
1676 
1677 	rw_wlock(&uma_rwlock);
1678 	LIST_INSERT_HEAD(&uma_kegs, keg, uk_link);
1679 	rw_wunlock(&uma_rwlock);
1680 	return (0);
1681 }
1682 
1683 /*
1684  * Zone header ctor.  This initializes all fields, locks, etc.
1685  *
1686  * Arguments/Returns follow uma_ctor specifications
1687  *	udata  Actually uma_zctor_args
1688  */
1689 static int
1690 zone_ctor(void *mem, int size, void *udata, int flags)
1691 {
1692 	struct uma_zctor_args *arg = udata;
1693 	uma_zone_t zone = mem;
1694 	uma_zone_t z;
1695 	uma_keg_t keg;
1696 
1697 	bzero(zone, size);
1698 	zone->uz_name = arg->name;
1699 	zone->uz_ctor = arg->ctor;
1700 	zone->uz_dtor = arg->dtor;
1701 	zone->uz_slab = zone_fetch_slab;
1702 	zone->uz_init = NULL;
1703 	zone->uz_fini = NULL;
1704 	zone->uz_allocs = 0;
1705 	zone->uz_frees = 0;
1706 	zone->uz_fails = 0;
1707 	zone->uz_sleeps = 0;
1708 	zone->uz_count = 0;
1709 	zone->uz_count_min = 0;
1710 	zone->uz_flags = 0;
1711 	zone->uz_warning = NULL;
1712 	/* The domain structures follow the cpu structures. */
1713 	zone->uz_domain = (struct uma_zone_domain *)&zone->uz_cpu[mp_ncpus];
1714 	timevalclear(&zone->uz_ratecheck);
1715 	keg = arg->keg;
1716 
1717 	ZONE_LOCK_INIT(zone, (arg->flags & UMA_ZONE_MTXCLASS));
1718 
1719 	/*
1720 	 * This is a pure cache zone, no kegs.
1721 	 */
1722 	if (arg->import) {
1723 		if (arg->flags & UMA_ZONE_VM)
1724 			arg->flags |= UMA_ZFLAG_CACHEONLY;
1725 		zone->uz_flags = arg->flags;
1726 		zone->uz_size = arg->size;
1727 		zone->uz_import = arg->import;
1728 		zone->uz_release = arg->release;
1729 		zone->uz_arg = arg->arg;
1730 		zone->uz_lockptr = &zone->uz_lock;
1731 		rw_wlock(&uma_rwlock);
1732 		LIST_INSERT_HEAD(&uma_cachezones, zone, uz_link);
1733 		rw_wunlock(&uma_rwlock);
1734 		goto out;
1735 	}
1736 
1737 	/*
1738 	 * Use the regular zone/keg/slab allocator.
1739 	 */
1740 	zone->uz_import = (uma_import)zone_import;
1741 	zone->uz_release = (uma_release)zone_release;
1742 	zone->uz_arg = zone;
1743 
1744 	if (arg->flags & UMA_ZONE_SECONDARY) {
1745 		KASSERT(arg->keg != NULL, ("Secondary zone on zero'd keg"));
1746 		zone->uz_init = arg->uminit;
1747 		zone->uz_fini = arg->fini;
1748 		zone->uz_lockptr = &keg->uk_lock;
1749 		zone->uz_flags |= UMA_ZONE_SECONDARY;
1750 		rw_wlock(&uma_rwlock);
1751 		ZONE_LOCK(zone);
1752 		LIST_FOREACH(z, &keg->uk_zones, uz_link) {
1753 			if (LIST_NEXT(z, uz_link) == NULL) {
1754 				LIST_INSERT_AFTER(z, zone, uz_link);
1755 				break;
1756 			}
1757 		}
1758 		ZONE_UNLOCK(zone);
1759 		rw_wunlock(&uma_rwlock);
1760 	} else if (keg == NULL) {
1761 		if ((keg = uma_kcreate(zone, arg->size, arg->uminit, arg->fini,
1762 		    arg->align, arg->flags)) == NULL)
1763 			return (ENOMEM);
1764 	} else {
1765 		struct uma_kctor_args karg;
1766 		int error;
1767 
1768 		/* We should only be here from uma_startup() */
1769 		karg.size = arg->size;
1770 		karg.uminit = arg->uminit;
1771 		karg.fini = arg->fini;
1772 		karg.align = arg->align;
1773 		karg.flags = arg->flags;
1774 		karg.zone = zone;
1775 		error = keg_ctor(arg->keg, sizeof(struct uma_keg), &karg,
1776 		    flags);
1777 		if (error)
1778 			return (error);
1779 	}
1780 
1781 	/*
1782 	 * Link in the first keg.
1783 	 */
1784 	zone->uz_klink.kl_keg = keg;
1785 	LIST_INSERT_HEAD(&zone->uz_kegs, &zone->uz_klink, kl_link);
1786 	zone->uz_lockptr = &keg->uk_lock;
1787 	zone->uz_size = keg->uk_size;
1788 	zone->uz_flags |= (keg->uk_flags &
1789 	    (UMA_ZONE_INHERIT | UMA_ZFLAG_INHERIT));
1790 
1791 	/*
1792 	 * Some internal zones don't have room allocated for the per cpu
1793 	 * caches.  If we're internal, bail out here.
1794 	 */
1795 	if (keg->uk_flags & UMA_ZFLAG_INTERNAL) {
1796 		KASSERT((zone->uz_flags & UMA_ZONE_SECONDARY) == 0,
1797 		    ("Secondary zone requested UMA_ZFLAG_INTERNAL"));
1798 		return (0);
1799 	}
1800 
1801 out:
1802 	KASSERT((arg->flags & (UMA_ZONE_MAXBUCKET | UMA_ZONE_NOBUCKET)) !=
1803 	    (UMA_ZONE_MAXBUCKET | UMA_ZONE_NOBUCKET),
1804 	    ("Invalid zone flag combination"));
1805 	if ((arg->flags & UMA_ZONE_MAXBUCKET) != 0)
1806 		zone->uz_count = BUCKET_MAX;
1807 	else if ((arg->flags & UMA_ZONE_NOBUCKET) != 0)
1808 		zone->uz_count = 0;
1809 	else
1810 		zone->uz_count = bucket_select(zone->uz_size);
1811 	zone->uz_count_min = zone->uz_count;
1812 
1813 	return (0);
1814 }
1815 
1816 /*
1817  * Keg header dtor.  This frees all data, destroys locks, frees the hash
1818  * table and removes the keg from the global list.
1819  *
1820  * Arguments/Returns follow uma_dtor specifications
1821  *	udata  unused
1822  */
1823 static void
1824 keg_dtor(void *arg, int size, void *udata)
1825 {
1826 	uma_keg_t keg;
1827 
1828 	keg = (uma_keg_t)arg;
1829 	KEG_LOCK(keg);
1830 	if (keg->uk_free != 0) {
1831 		printf("Freed UMA keg (%s) was not empty (%d items). "
1832 		    " Lost %d pages of memory.\n",
1833 		    keg->uk_name ? keg->uk_name : "",
1834 		    keg->uk_free, keg->uk_pages);
1835 	}
1836 	KEG_UNLOCK(keg);
1837 
1838 	hash_free(&keg->uk_hash);
1839 
1840 	KEG_LOCK_FINI(keg);
1841 }
1842 
1843 /*
1844  * Zone header dtor.
1845  *
1846  * Arguments/Returns follow uma_dtor specifications
1847  *	udata  unused
1848  */
1849 static void
1850 zone_dtor(void *arg, int size, void *udata)
1851 {
1852 	uma_klink_t klink;
1853 	uma_zone_t zone;
1854 	uma_keg_t keg;
1855 
1856 	zone = (uma_zone_t)arg;
1857 	keg = zone_first_keg(zone);
1858 
1859 	if (!(zone->uz_flags & UMA_ZFLAG_INTERNAL))
1860 		cache_drain(zone);
1861 
1862 	rw_wlock(&uma_rwlock);
1863 	LIST_REMOVE(zone, uz_link);
1864 	rw_wunlock(&uma_rwlock);
1865 	/*
1866 	 * XXX there are some races here where
1867 	 * the zone can be drained but zone lock
1868 	 * released and then refilled before we
1869 	 * remove it... we dont care for now
1870 	 */
1871 	zone_drain_wait(zone, M_WAITOK);
1872 	/*
1873 	 * Unlink all of our kegs.
1874 	 */
1875 	while ((klink = LIST_FIRST(&zone->uz_kegs)) != NULL) {
1876 		klink->kl_keg = NULL;
1877 		LIST_REMOVE(klink, kl_link);
1878 		if (klink == &zone->uz_klink)
1879 			continue;
1880 		free(klink, M_TEMP);
1881 	}
1882 	/*
1883 	 * We only destroy kegs from non secondary zones.
1884 	 */
1885 	if (keg != NULL && (zone->uz_flags & UMA_ZONE_SECONDARY) == 0)  {
1886 		rw_wlock(&uma_rwlock);
1887 		LIST_REMOVE(keg, uk_link);
1888 		rw_wunlock(&uma_rwlock);
1889 		zone_free_item(kegs, keg, NULL, SKIP_NONE);
1890 	}
1891 	ZONE_LOCK_FINI(zone);
1892 }
1893 
1894 /*
1895  * Traverses every zone in the system and calls a callback
1896  *
1897  * Arguments:
1898  *	zfunc  A pointer to a function which accepts a zone
1899  *		as an argument.
1900  *
1901  * Returns:
1902  *	Nothing
1903  */
1904 static void
1905 zone_foreach(void (*zfunc)(uma_zone_t))
1906 {
1907 	uma_keg_t keg;
1908 	uma_zone_t zone;
1909 
1910 	rw_rlock(&uma_rwlock);
1911 	LIST_FOREACH(keg, &uma_kegs, uk_link) {
1912 		LIST_FOREACH(zone, &keg->uk_zones, uz_link)
1913 			zfunc(zone);
1914 	}
1915 	rw_runlock(&uma_rwlock);
1916 }
1917 
1918 /*
1919  * Count how many pages do we need to bootstrap.  VM supplies
1920  * its need in early zones in the argument, we add up our zones,
1921  * which consist of: UMA Slabs, UMA Hash and 9 Bucket zones. The
1922  * zone of zones and zone of kegs are accounted separately.
1923  */
1924 #define	UMA_BOOT_ZONES	11
1925 /* Zone of zones and zone of kegs have arbitrary alignment. */
1926 #define	UMA_BOOT_ALIGN	32
1927 static int zsize, ksize;
1928 int
1929 uma_startup_count(int vm_zones)
1930 {
1931 	int zones, pages;
1932 
1933 	ksize = sizeof(struct uma_keg) +
1934 	    (sizeof(struct uma_domain) * vm_ndomains);
1935 	zsize = sizeof(struct uma_zone) +
1936 	    (sizeof(struct uma_cache) * (mp_maxid + 1)) +
1937 	    (sizeof(struct uma_zone_domain) * vm_ndomains);
1938 
1939 	/*
1940 	 * Memory for the zone of kegs and its keg,
1941 	 * and for zone of zones.
1942 	 */
1943 	pages = howmany(roundup(zsize, CACHE_LINE_SIZE) * 2 +
1944 	    roundup(ksize, CACHE_LINE_SIZE), PAGE_SIZE);
1945 
1946 #ifdef	UMA_MD_SMALL_ALLOC
1947 	zones = UMA_BOOT_ZONES;
1948 #else
1949 	zones = UMA_BOOT_ZONES + vm_zones;
1950 	vm_zones = 0;
1951 #endif
1952 
1953 	/* Memory for the rest of startup zones, UMA and VM, ... */
1954 	if (zsize > UMA_SLAB_SPACE)
1955 		pages += (zones + vm_zones) *
1956 		    howmany(roundup2(zsize, UMA_BOOT_ALIGN), UMA_SLAB_SIZE);
1957 	else if (roundup2(zsize, UMA_BOOT_ALIGN) > UMA_SLAB_SPACE)
1958 		pages += zones;
1959 	else
1960 		pages += howmany(zones,
1961 		    UMA_SLAB_SPACE / roundup2(zsize, UMA_BOOT_ALIGN));
1962 
1963 	/* ... and their kegs. Note that zone of zones allocates a keg! */
1964 	pages += howmany(zones + 1,
1965 	    UMA_SLAB_SPACE / roundup2(ksize, UMA_BOOT_ALIGN));
1966 
1967 	/*
1968 	 * Most of startup zones are not going to be offpages, that's
1969 	 * why we use UMA_SLAB_SPACE instead of UMA_SLAB_SIZE in all
1970 	 * calculations.  Some large bucket zones will be offpage, and
1971 	 * thus will allocate hashes.  We take conservative approach
1972 	 * and assume that all zones may allocate hash.  This may give
1973 	 * us some positive inaccuracy, usually an extra single page.
1974 	 */
1975 	pages += howmany(zones, UMA_SLAB_SPACE /
1976 	    (sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT));
1977 
1978 	return (pages);
1979 }
1980 
1981 void
1982 uma_startup(void *mem, int npages)
1983 {
1984 	struct uma_zctor_args args;
1985 	uma_keg_t masterkeg;
1986 	uintptr_t m;
1987 
1988 #ifdef DIAGNOSTIC
1989 	printf("Entering %s with %d boot pages configured\n", __func__, npages);
1990 #endif
1991 
1992 	rw_init(&uma_rwlock, "UMA lock");
1993 
1994 	/* Use bootpages memory for the zone of zones and zone of kegs. */
1995 	m = (uintptr_t)mem;
1996 	zones = (uma_zone_t)m;
1997 	m += roundup(zsize, CACHE_LINE_SIZE);
1998 	kegs = (uma_zone_t)m;
1999 	m += roundup(zsize, CACHE_LINE_SIZE);
2000 	masterkeg = (uma_keg_t)m;
2001 	m += roundup(ksize, CACHE_LINE_SIZE);
2002 	m = roundup(m, PAGE_SIZE);
2003 	npages -= (m - (uintptr_t)mem) / PAGE_SIZE;
2004 	mem = (void *)m;
2005 
2006 	/* "manually" create the initial zone */
2007 	memset(&args, 0, sizeof(args));
2008 	args.name = "UMA Kegs";
2009 	args.size = ksize;
2010 	args.ctor = keg_ctor;
2011 	args.dtor = keg_dtor;
2012 	args.uminit = zero_init;
2013 	args.fini = NULL;
2014 	args.keg = masterkeg;
2015 	args.align = UMA_BOOT_ALIGN - 1;
2016 	args.flags = UMA_ZFLAG_INTERNAL;
2017 	zone_ctor(kegs, zsize, &args, M_WAITOK);
2018 
2019 	bootmem = mem;
2020 	boot_pages = npages;
2021 
2022 	args.name = "UMA Zones";
2023 	args.size = zsize;
2024 	args.ctor = zone_ctor;
2025 	args.dtor = zone_dtor;
2026 	args.uminit = zero_init;
2027 	args.fini = NULL;
2028 	args.keg = NULL;
2029 	args.align = UMA_BOOT_ALIGN - 1;
2030 	args.flags = UMA_ZFLAG_INTERNAL;
2031 	zone_ctor(zones, zsize, &args, M_WAITOK);
2032 
2033 	/* Now make a zone for slab headers */
2034 	slabzone = uma_zcreate("UMA Slabs",
2035 				sizeof(struct uma_slab),
2036 				NULL, NULL, NULL, NULL,
2037 				UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
2038 
2039 	hashzone = uma_zcreate("UMA Hash",
2040 	    sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT,
2041 	    NULL, NULL, NULL, NULL,
2042 	    UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
2043 
2044 	bucket_init();
2045 
2046 	booted = BOOT_STRAPPED;
2047 }
2048 
2049 void
2050 uma_startup1(void)
2051 {
2052 
2053 #ifdef DIAGNOSTIC
2054 	printf("Entering %s with %d boot pages left\n", __func__, boot_pages);
2055 #endif
2056 	booted = BOOT_PAGEALLOC;
2057 }
2058 
2059 void
2060 uma_startup2(void)
2061 {
2062 
2063 #ifdef DIAGNOSTIC
2064 	printf("Entering %s with %d boot pages left\n", __func__, boot_pages);
2065 #endif
2066 	booted = BOOT_BUCKETS;
2067 	sx_init(&uma_drain_lock, "umadrain");
2068 	bucket_enable();
2069 }
2070 
2071 /*
2072  * Initialize our callout handle
2073  *
2074  */
2075 static void
2076 uma_startup3(void)
2077 {
2078 
2079 #ifdef INVARIANTS
2080 	TUNABLE_INT_FETCH("vm.debug.divisor", &dbg_divisor);
2081 	uma_dbg_cnt = counter_u64_alloc(M_WAITOK);
2082 	uma_skip_cnt = counter_u64_alloc(M_WAITOK);
2083 #endif
2084 	callout_init(&uma_callout, 1);
2085 	callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
2086 	booted = BOOT_RUNNING;
2087 }
2088 
2089 static uma_keg_t
2090 uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini,
2091 		int align, uint32_t flags)
2092 {
2093 	struct uma_kctor_args args;
2094 
2095 	args.size = size;
2096 	args.uminit = uminit;
2097 	args.fini = fini;
2098 	args.align = (align == UMA_ALIGN_CACHE) ? uma_align_cache : align;
2099 	args.flags = flags;
2100 	args.zone = zone;
2101 	return (zone_alloc_item(kegs, &args, UMA_ANYDOMAIN, M_WAITOK));
2102 }
2103 
2104 /* Public functions */
2105 /* See uma.h */
2106 void
2107 uma_set_align(int align)
2108 {
2109 
2110 	if (align != UMA_ALIGN_CACHE)
2111 		uma_align_cache = align;
2112 }
2113 
2114 /* See uma.h */
2115 uma_zone_t
2116 uma_zcreate(const char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
2117 		uma_init uminit, uma_fini fini, int align, uint32_t flags)
2118 
2119 {
2120 	struct uma_zctor_args args;
2121 	uma_zone_t res;
2122 	bool locked;
2123 
2124 	KASSERT(powerof2(align + 1), ("invalid zone alignment %d for \"%s\"",
2125 	    align, name));
2126 
2127 	/* This stuff is essential for the zone ctor */
2128 	memset(&args, 0, sizeof(args));
2129 	args.name = name;
2130 	args.size = size;
2131 	args.ctor = ctor;
2132 	args.dtor = dtor;
2133 	args.uminit = uminit;
2134 	args.fini = fini;
2135 #ifdef  INVARIANTS
2136 	/*
2137 	 * If a zone is being created with an empty constructor and
2138 	 * destructor, pass UMA constructor/destructor which checks for
2139 	 * memory use after free.
2140 	 */
2141 	if ((!(flags & (UMA_ZONE_ZINIT | UMA_ZONE_NOFREE))) &&
2142 	    ctor == NULL && dtor == NULL && uminit == NULL && fini == NULL) {
2143 		args.ctor = trash_ctor;
2144 		args.dtor = trash_dtor;
2145 		args.uminit = trash_init;
2146 		args.fini = trash_fini;
2147 	}
2148 #endif
2149 	args.align = align;
2150 	args.flags = flags;
2151 	args.keg = NULL;
2152 
2153 	if (booted < BOOT_BUCKETS) {
2154 		locked = false;
2155 	} else {
2156 		sx_slock(&uma_drain_lock);
2157 		locked = true;
2158 	}
2159 	res = zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK);
2160 	if (locked)
2161 		sx_sunlock(&uma_drain_lock);
2162 	return (res);
2163 }
2164 
2165 /* See uma.h */
2166 uma_zone_t
2167 uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
2168 		    uma_init zinit, uma_fini zfini, uma_zone_t master)
2169 {
2170 	struct uma_zctor_args args;
2171 	uma_keg_t keg;
2172 	uma_zone_t res;
2173 	bool locked;
2174 
2175 	keg = zone_first_keg(master);
2176 	memset(&args, 0, sizeof(args));
2177 	args.name = name;
2178 	args.size = keg->uk_size;
2179 	args.ctor = ctor;
2180 	args.dtor = dtor;
2181 	args.uminit = zinit;
2182 	args.fini = zfini;
2183 	args.align = keg->uk_align;
2184 	args.flags = keg->uk_flags | UMA_ZONE_SECONDARY;
2185 	args.keg = keg;
2186 
2187 	if (booted < BOOT_BUCKETS) {
2188 		locked = false;
2189 	} else {
2190 		sx_slock(&uma_drain_lock);
2191 		locked = true;
2192 	}
2193 	/* XXX Attaches only one keg of potentially many. */
2194 	res = zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK);
2195 	if (locked)
2196 		sx_sunlock(&uma_drain_lock);
2197 	return (res);
2198 }
2199 
2200 /* See uma.h */
2201 uma_zone_t
2202 uma_zcache_create(char *name, int size, uma_ctor ctor, uma_dtor dtor,
2203 		    uma_init zinit, uma_fini zfini, uma_import zimport,
2204 		    uma_release zrelease, void *arg, int flags)
2205 {
2206 	struct uma_zctor_args args;
2207 
2208 	memset(&args, 0, sizeof(args));
2209 	args.name = name;
2210 	args.size = size;
2211 	args.ctor = ctor;
2212 	args.dtor = dtor;
2213 	args.uminit = zinit;
2214 	args.fini = zfini;
2215 	args.import = zimport;
2216 	args.release = zrelease;
2217 	args.arg = arg;
2218 	args.align = 0;
2219 	args.flags = flags;
2220 
2221 	return (zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK));
2222 }
2223 
2224 static void
2225 zone_lock_pair(uma_zone_t a, uma_zone_t b)
2226 {
2227 	if (a < b) {
2228 		ZONE_LOCK(a);
2229 		mtx_lock_flags(b->uz_lockptr, MTX_DUPOK);
2230 	} else {
2231 		ZONE_LOCK(b);
2232 		mtx_lock_flags(a->uz_lockptr, MTX_DUPOK);
2233 	}
2234 }
2235 
2236 static void
2237 zone_unlock_pair(uma_zone_t a, uma_zone_t b)
2238 {
2239 
2240 	ZONE_UNLOCK(a);
2241 	ZONE_UNLOCK(b);
2242 }
2243 
2244 int
2245 uma_zsecond_add(uma_zone_t zone, uma_zone_t master)
2246 {
2247 	uma_klink_t klink;
2248 	uma_klink_t kl;
2249 	int error;
2250 
2251 	error = 0;
2252 	klink = malloc(sizeof(*klink), M_TEMP, M_WAITOK | M_ZERO);
2253 
2254 	zone_lock_pair(zone, master);
2255 	/*
2256 	 * zone must use vtoslab() to resolve objects and must already be
2257 	 * a secondary.
2258 	 */
2259 	if ((zone->uz_flags & (UMA_ZONE_VTOSLAB | UMA_ZONE_SECONDARY))
2260 	    != (UMA_ZONE_VTOSLAB | UMA_ZONE_SECONDARY)) {
2261 		error = EINVAL;
2262 		goto out;
2263 	}
2264 	/*
2265 	 * The new master must also use vtoslab().
2266 	 */
2267 	if ((zone->uz_flags & UMA_ZONE_VTOSLAB) != UMA_ZONE_VTOSLAB) {
2268 		error = EINVAL;
2269 		goto out;
2270 	}
2271 
2272 	/*
2273 	 * The underlying object must be the same size.  rsize
2274 	 * may be different.
2275 	 */
2276 	if (master->uz_size != zone->uz_size) {
2277 		error = E2BIG;
2278 		goto out;
2279 	}
2280 	/*
2281 	 * Put it at the end of the list.
2282 	 */
2283 	klink->kl_keg = zone_first_keg(master);
2284 	LIST_FOREACH(kl, &zone->uz_kegs, kl_link) {
2285 		if (LIST_NEXT(kl, kl_link) == NULL) {
2286 			LIST_INSERT_AFTER(kl, klink, kl_link);
2287 			break;
2288 		}
2289 	}
2290 	klink = NULL;
2291 	zone->uz_flags |= UMA_ZFLAG_MULTI;
2292 	zone->uz_slab = zone_fetch_slab_multi;
2293 
2294 out:
2295 	zone_unlock_pair(zone, master);
2296 	if (klink != NULL)
2297 		free(klink, M_TEMP);
2298 
2299 	return (error);
2300 }
2301 
2302 
2303 /* See uma.h */
2304 void
2305 uma_zdestroy(uma_zone_t zone)
2306 {
2307 
2308 	sx_slock(&uma_drain_lock);
2309 	zone_free_item(zones, zone, NULL, SKIP_NONE);
2310 	sx_sunlock(&uma_drain_lock);
2311 }
2312 
2313 void
2314 uma_zwait(uma_zone_t zone)
2315 {
2316 	void *item;
2317 
2318 	item = uma_zalloc_arg(zone, NULL, M_WAITOK);
2319 	uma_zfree(zone, item);
2320 }
2321 
2322 void *
2323 uma_zalloc_pcpu_arg(uma_zone_t zone, void *udata, int flags)
2324 {
2325 	void *item;
2326 #ifdef SMP
2327 	int i;
2328 
2329 	MPASS(zone->uz_flags & UMA_ZONE_PCPU);
2330 #endif
2331 	item = uma_zalloc_arg(zone, udata, flags &~ M_ZERO);
2332 	if (item != NULL && (flags & M_ZERO)) {
2333 #ifdef SMP
2334 		CPU_FOREACH(i)
2335 			bzero(zpcpu_get_cpu(item, i), zone->uz_size);
2336 #else
2337 		bzero(item, zone->uz_size);
2338 #endif
2339 	}
2340 	return (item);
2341 }
2342 
2343 /*
2344  * A stub while both regular and pcpu cases are identical.
2345  */
2346 void
2347 uma_zfree_pcpu_arg(uma_zone_t zone, void *item, void *udata)
2348 {
2349 
2350 #ifdef SMP
2351 	MPASS(zone->uz_flags & UMA_ZONE_PCPU);
2352 #endif
2353 	uma_zfree_arg(zone, item, udata);
2354 }
2355 
2356 /* See uma.h */
2357 void *
2358 uma_zalloc_arg(uma_zone_t zone, void *udata, int flags)
2359 {
2360 	uma_zone_domain_t zdom;
2361 	uma_bucket_t bucket;
2362 	uma_cache_t cache;
2363 	void *item;
2364 	int cpu, domain, lockfail;
2365 #ifdef INVARIANTS
2366 	bool skipdbg;
2367 #endif
2368 
2369 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
2370 	random_harvest_fast_uma(&zone, sizeof(zone), 1, RANDOM_UMA);
2371 
2372 	/* This is the fast path allocation */
2373 	CTR4(KTR_UMA, "uma_zalloc_arg thread %x zone %s(%p) flags %d",
2374 	    curthread, zone->uz_name, zone, flags);
2375 
2376 	if (flags & M_WAITOK) {
2377 		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
2378 		    "uma_zalloc_arg: zone \"%s\"", zone->uz_name);
2379 	}
2380 	KASSERT((flags & M_EXEC) == 0, ("uma_zalloc_arg: called with M_EXEC"));
2381 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
2382 	    ("uma_zalloc_arg: called with spinlock or critical section held"));
2383 	if (zone->uz_flags & UMA_ZONE_PCPU)
2384 		KASSERT((flags & M_ZERO) == 0, ("allocating from a pcpu zone "
2385 		    "with M_ZERO passed"));
2386 
2387 #ifdef DEBUG_MEMGUARD
2388 	if (memguard_cmp_zone(zone)) {
2389 		item = memguard_alloc(zone->uz_size, flags);
2390 		if (item != NULL) {
2391 			if (zone->uz_init != NULL &&
2392 			    zone->uz_init(item, zone->uz_size, flags) != 0)
2393 				return (NULL);
2394 			if (zone->uz_ctor != NULL &&
2395 			    zone->uz_ctor(item, zone->uz_size, udata,
2396 			    flags) != 0) {
2397 			    	zone->uz_fini(item, zone->uz_size);
2398 				return (NULL);
2399 			}
2400 			return (item);
2401 		}
2402 		/* This is unfortunate but should not be fatal. */
2403 	}
2404 #endif
2405 	/*
2406 	 * If possible, allocate from the per-CPU cache.  There are two
2407 	 * requirements for safe access to the per-CPU cache: (1) the thread
2408 	 * accessing the cache must not be preempted or yield during access,
2409 	 * and (2) the thread must not migrate CPUs without switching which
2410 	 * cache it accesses.  We rely on a critical section to prevent
2411 	 * preemption and migration.  We release the critical section in
2412 	 * order to acquire the zone mutex if we are unable to allocate from
2413 	 * the current cache; when we re-acquire the critical section, we
2414 	 * must detect and handle migration if it has occurred.
2415 	 */
2416 	critical_enter();
2417 	cpu = curcpu;
2418 	cache = &zone->uz_cpu[cpu];
2419 
2420 zalloc_start:
2421 	bucket = cache->uc_allocbucket;
2422 	if (bucket != NULL && bucket->ub_cnt > 0) {
2423 		bucket->ub_cnt--;
2424 		item = bucket->ub_bucket[bucket->ub_cnt];
2425 #ifdef INVARIANTS
2426 		bucket->ub_bucket[bucket->ub_cnt] = NULL;
2427 #endif
2428 		KASSERT(item != NULL, ("uma_zalloc: Bucket pointer mangled."));
2429 		cache->uc_allocs++;
2430 		critical_exit();
2431 #ifdef INVARIANTS
2432 		skipdbg = uma_dbg_zskip(zone, item);
2433 #endif
2434 		if (zone->uz_ctor != NULL &&
2435 #ifdef INVARIANTS
2436 		    (!skipdbg || zone->uz_ctor != trash_ctor ||
2437 		    zone->uz_dtor != trash_dtor) &&
2438 #endif
2439 		    zone->uz_ctor(item, zone->uz_size, udata, flags) != 0) {
2440 			atomic_add_long(&zone->uz_fails, 1);
2441 			zone_free_item(zone, item, udata, SKIP_DTOR);
2442 			return (NULL);
2443 		}
2444 #ifdef INVARIANTS
2445 		if (!skipdbg)
2446 			uma_dbg_alloc(zone, NULL, item);
2447 #endif
2448 		if (flags & M_ZERO)
2449 			uma_zero_item(item, zone);
2450 		return (item);
2451 	}
2452 
2453 	/*
2454 	 * We have run out of items in our alloc bucket.
2455 	 * See if we can switch with our free bucket.
2456 	 */
2457 	bucket = cache->uc_freebucket;
2458 	if (bucket != NULL && bucket->ub_cnt > 0) {
2459 		CTR2(KTR_UMA,
2460 		    "uma_zalloc: zone %s(%p) swapping empty with alloc",
2461 		    zone->uz_name, zone);
2462 		cache->uc_freebucket = cache->uc_allocbucket;
2463 		cache->uc_allocbucket = bucket;
2464 		goto zalloc_start;
2465 	}
2466 
2467 	/*
2468 	 * Discard any empty allocation bucket while we hold no locks.
2469 	 */
2470 	bucket = cache->uc_allocbucket;
2471 	cache->uc_allocbucket = NULL;
2472 	critical_exit();
2473 	if (bucket != NULL)
2474 		bucket_free(zone, bucket, udata);
2475 
2476 	if (zone->uz_flags & UMA_ZONE_NUMA)
2477 		domain = PCPU_GET(domain);
2478 	else
2479 		domain = UMA_ANYDOMAIN;
2480 
2481 	/* Short-circuit for zones without buckets and low memory. */
2482 	if (zone->uz_count == 0 || bucketdisable)
2483 		goto zalloc_item;
2484 
2485 	/*
2486 	 * Attempt to retrieve the item from the per-CPU cache has failed, so
2487 	 * we must go back to the zone.  This requires the zone lock, so we
2488 	 * must drop the critical section, then re-acquire it when we go back
2489 	 * to the cache.  Since the critical section is released, we may be
2490 	 * preempted or migrate.  As such, make sure not to maintain any
2491 	 * thread-local state specific to the cache from prior to releasing
2492 	 * the critical section.
2493 	 */
2494 	lockfail = 0;
2495 	if (ZONE_TRYLOCK(zone) == 0) {
2496 		/* Record contention to size the buckets. */
2497 		ZONE_LOCK(zone);
2498 		lockfail = 1;
2499 	}
2500 	critical_enter();
2501 	cpu = curcpu;
2502 	cache = &zone->uz_cpu[cpu];
2503 
2504 	/* See if we lost the race to fill the cache. */
2505 	if (cache->uc_allocbucket != NULL) {
2506 		ZONE_UNLOCK(zone);
2507 		goto zalloc_start;
2508 	}
2509 
2510 	/*
2511 	 * Check the zone's cache of buckets.
2512 	 */
2513 	if (domain == UMA_ANYDOMAIN)
2514 		zdom = &zone->uz_domain[0];
2515 	else
2516 		zdom = &zone->uz_domain[domain];
2517 	if ((bucket = LIST_FIRST(&zdom->uzd_buckets)) != NULL) {
2518 		KASSERT(bucket->ub_cnt != 0,
2519 		    ("uma_zalloc_arg: Returning an empty bucket."));
2520 
2521 		LIST_REMOVE(bucket, ub_link);
2522 		cache->uc_allocbucket = bucket;
2523 		ZONE_UNLOCK(zone);
2524 		goto zalloc_start;
2525 	}
2526 	/* We are no longer associated with this CPU. */
2527 	critical_exit();
2528 
2529 	/*
2530 	 * We bump the uz count when the cache size is insufficient to
2531 	 * handle the working set.
2532 	 */
2533 	if (lockfail && zone->uz_count < BUCKET_MAX)
2534 		zone->uz_count++;
2535 	ZONE_UNLOCK(zone);
2536 
2537 	/*
2538 	 * Now lets just fill a bucket and put it on the free list.  If that
2539 	 * works we'll restart the allocation from the beginning and it
2540 	 * will use the just filled bucket.
2541 	 */
2542 	bucket = zone_alloc_bucket(zone, udata, domain, flags);
2543 	CTR3(KTR_UMA, "uma_zalloc: zone %s(%p) bucket zone returned %p",
2544 	    zone->uz_name, zone, bucket);
2545 	if (bucket != NULL) {
2546 		ZONE_LOCK(zone);
2547 		critical_enter();
2548 		cpu = curcpu;
2549 		cache = &zone->uz_cpu[cpu];
2550 		/*
2551 		 * See if we lost the race or were migrated.  Cache the
2552 		 * initialized bucket to make this less likely or claim
2553 		 * the memory directly.
2554 		 */
2555 		if (cache->uc_allocbucket != NULL ||
2556 		    (zone->uz_flags & UMA_ZONE_NUMA &&
2557 		    domain != PCPU_GET(domain)))
2558 			LIST_INSERT_HEAD(&zdom->uzd_buckets, bucket, ub_link);
2559 		else
2560 			cache->uc_allocbucket = bucket;
2561 		ZONE_UNLOCK(zone);
2562 		goto zalloc_start;
2563 	}
2564 
2565 	/*
2566 	 * We may not be able to get a bucket so return an actual item.
2567 	 */
2568 zalloc_item:
2569 	item = zone_alloc_item(zone, udata, domain, flags);
2570 
2571 	return (item);
2572 }
2573 
2574 void *
2575 uma_zalloc_domain(uma_zone_t zone, void *udata, int domain, int flags)
2576 {
2577 
2578 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
2579 	random_harvest_fast_uma(&zone, sizeof(zone), 1, RANDOM_UMA);
2580 
2581 	/* This is the fast path allocation */
2582 	CTR5(KTR_UMA,
2583 	    "uma_zalloc_domain thread %x zone %s(%p) domain %d flags %d",
2584 	    curthread, zone->uz_name, zone, domain, flags);
2585 
2586 	if (flags & M_WAITOK) {
2587 		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
2588 		    "uma_zalloc_domain: zone \"%s\"", zone->uz_name);
2589 	}
2590 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
2591 	    ("uma_zalloc_domain: called with spinlock or critical section held"));
2592 
2593 	return (zone_alloc_item(zone, udata, domain, flags));
2594 }
2595 
2596 /*
2597  * Find a slab with some space.  Prefer slabs that are partially used over those
2598  * that are totally full.  This helps to reduce fragmentation.
2599  *
2600  * If 'rr' is 1, search all domains starting from 'domain'.  Otherwise check
2601  * only 'domain'.
2602  */
2603 static uma_slab_t
2604 keg_first_slab(uma_keg_t keg, int domain, int rr)
2605 {
2606 	uma_domain_t dom;
2607 	uma_slab_t slab;
2608 	int start;
2609 
2610 	KASSERT(domain >= 0 && domain < vm_ndomains,
2611 	    ("keg_first_slab: domain %d out of range", domain));
2612 
2613 	slab = NULL;
2614 	start = domain;
2615 	do {
2616 		dom = &keg->uk_domain[domain];
2617 		if (!LIST_EMPTY(&dom->ud_part_slab))
2618 			return (LIST_FIRST(&dom->ud_part_slab));
2619 		if (!LIST_EMPTY(&dom->ud_free_slab)) {
2620 			slab = LIST_FIRST(&dom->ud_free_slab);
2621 			LIST_REMOVE(slab, us_link);
2622 			LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
2623 			return (slab);
2624 		}
2625 		if (rr)
2626 			domain = (domain + 1) % vm_ndomains;
2627 	} while (domain != start);
2628 
2629 	return (NULL);
2630 }
2631 
2632 static uma_slab_t
2633 keg_fetch_slab(uma_keg_t keg, uma_zone_t zone, int rdomain, int flags)
2634 {
2635 	uma_domain_t dom;
2636 	uma_slab_t slab;
2637 	int allocflags, domain, reserve, rr, start;
2638 
2639 	mtx_assert(&keg->uk_lock, MA_OWNED);
2640 	slab = NULL;
2641 	reserve = 0;
2642 	allocflags = flags;
2643 	if ((flags & M_USE_RESERVE) == 0)
2644 		reserve = keg->uk_reserve;
2645 
2646 	/*
2647 	 * Round-robin for non first-touch zones when there is more than one
2648 	 * domain.
2649 	 */
2650 	if (vm_ndomains == 1)
2651 		rdomain = 0;
2652 	rr = rdomain == UMA_ANYDOMAIN;
2653 	if (rr) {
2654 		keg->uk_cursor = (keg->uk_cursor + 1) % vm_ndomains;
2655 		domain = start = keg->uk_cursor;
2656 		/* Only block on the second pass. */
2657 		if ((flags & (M_WAITOK | M_NOVM)) == M_WAITOK)
2658 			allocflags = (allocflags & ~M_WAITOK) | M_NOWAIT;
2659 	} else
2660 		domain = start = rdomain;
2661 
2662 again:
2663 	do {
2664 		if (keg->uk_free > reserve &&
2665 		    (slab = keg_first_slab(keg, domain, rr)) != NULL) {
2666 			MPASS(slab->us_keg == keg);
2667 			return (slab);
2668 		}
2669 
2670 		/*
2671 		 * M_NOVM means don't ask at all!
2672 		 */
2673 		if (flags & M_NOVM)
2674 			break;
2675 
2676 		if (keg->uk_maxpages && keg->uk_pages >= keg->uk_maxpages) {
2677 			keg->uk_flags |= UMA_ZFLAG_FULL;
2678 			/*
2679 			 * If this is not a multi-zone, set the FULL bit.
2680 			 * Otherwise slab_multi() takes care of it.
2681 			 */
2682 			if ((zone->uz_flags & UMA_ZFLAG_MULTI) == 0) {
2683 				zone->uz_flags |= UMA_ZFLAG_FULL;
2684 				zone_log_warning(zone);
2685 				zone_maxaction(zone);
2686 			}
2687 			if (flags & M_NOWAIT)
2688 				return (NULL);
2689 			zone->uz_sleeps++;
2690 			msleep(keg, &keg->uk_lock, PVM, "keglimit", 0);
2691 			continue;
2692 		}
2693 		slab = keg_alloc_slab(keg, zone, domain, allocflags);
2694 		/*
2695 		 * If we got a slab here it's safe to mark it partially used
2696 		 * and return.  We assume that the caller is going to remove
2697 		 * at least one item.
2698 		 */
2699 		if (slab) {
2700 			MPASS(slab->us_keg == keg);
2701 			dom = &keg->uk_domain[slab->us_domain];
2702 			LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
2703 			return (slab);
2704 		}
2705 		if (rr) {
2706 			keg->uk_cursor = (keg->uk_cursor + 1) % vm_ndomains;
2707 			domain = keg->uk_cursor;
2708 		}
2709 	} while (domain != start);
2710 
2711 	/* Retry domain scan with blocking. */
2712 	if (allocflags != flags) {
2713 		allocflags = flags;
2714 		goto again;
2715 	}
2716 
2717 	/*
2718 	 * We might not have been able to get a slab but another cpu
2719 	 * could have while we were unlocked.  Check again before we
2720 	 * fail.
2721 	 */
2722 	if (keg->uk_free > reserve &&
2723 	    (slab = keg_first_slab(keg, domain, rr)) != NULL) {
2724 		MPASS(slab->us_keg == keg);
2725 		return (slab);
2726 	}
2727 	return (NULL);
2728 }
2729 
2730 static uma_slab_t
2731 zone_fetch_slab(uma_zone_t zone, uma_keg_t keg, int domain, int flags)
2732 {
2733 	uma_slab_t slab;
2734 
2735 	if (keg == NULL) {
2736 		keg = zone_first_keg(zone);
2737 		KEG_LOCK(keg);
2738 	}
2739 
2740 	for (;;) {
2741 		slab = keg_fetch_slab(keg, zone, domain, flags);
2742 		if (slab)
2743 			return (slab);
2744 		if (flags & (M_NOWAIT | M_NOVM))
2745 			break;
2746 	}
2747 	KEG_UNLOCK(keg);
2748 	return (NULL);
2749 }
2750 
2751 /*
2752  * uma_zone_fetch_slab_multi:  Fetches a slab from one available keg.  Returns
2753  * with the keg locked.  On NULL no lock is held.
2754  *
2755  * The last pointer is used to seed the search.  It is not required.
2756  */
2757 static uma_slab_t
2758 zone_fetch_slab_multi(uma_zone_t zone, uma_keg_t last, int domain, int rflags)
2759 {
2760 	uma_klink_t klink;
2761 	uma_slab_t slab;
2762 	uma_keg_t keg;
2763 	int flags;
2764 	int empty;
2765 	int full;
2766 
2767 	/*
2768 	 * Don't wait on the first pass.  This will skip limit tests
2769 	 * as well.  We don't want to block if we can find a provider
2770 	 * without blocking.
2771 	 */
2772 	flags = (rflags & ~M_WAITOK) | M_NOWAIT;
2773 	/*
2774 	 * Use the last slab allocated as a hint for where to start
2775 	 * the search.
2776 	 */
2777 	if (last != NULL) {
2778 		slab = keg_fetch_slab(last, zone, domain, flags);
2779 		if (slab)
2780 			return (slab);
2781 		KEG_UNLOCK(last);
2782 	}
2783 	/*
2784 	 * Loop until we have a slab incase of transient failures
2785 	 * while M_WAITOK is specified.  I'm not sure this is 100%
2786 	 * required but we've done it for so long now.
2787 	 */
2788 	for (;;) {
2789 		empty = 0;
2790 		full = 0;
2791 		/*
2792 		 * Search the available kegs for slabs.  Be careful to hold the
2793 		 * correct lock while calling into the keg layer.
2794 		 */
2795 		LIST_FOREACH(klink, &zone->uz_kegs, kl_link) {
2796 			keg = klink->kl_keg;
2797 			KEG_LOCK(keg);
2798 			if ((keg->uk_flags & UMA_ZFLAG_FULL) == 0) {
2799 				slab = keg_fetch_slab(keg, zone, domain, flags);
2800 				if (slab)
2801 					return (slab);
2802 			}
2803 			if (keg->uk_flags & UMA_ZFLAG_FULL)
2804 				full++;
2805 			else
2806 				empty++;
2807 			KEG_UNLOCK(keg);
2808 		}
2809 		if (rflags & (M_NOWAIT | M_NOVM))
2810 			break;
2811 		flags = rflags;
2812 		/*
2813 		 * All kegs are full.  XXX We can't atomically check all kegs
2814 		 * and sleep so just sleep for a short period and retry.
2815 		 */
2816 		if (full && !empty) {
2817 			ZONE_LOCK(zone);
2818 			zone->uz_flags |= UMA_ZFLAG_FULL;
2819 			zone->uz_sleeps++;
2820 			zone_log_warning(zone);
2821 			zone_maxaction(zone);
2822 			msleep(zone, zone->uz_lockptr, PVM,
2823 			    "zonelimit", hz/100);
2824 			zone->uz_flags &= ~UMA_ZFLAG_FULL;
2825 			ZONE_UNLOCK(zone);
2826 			continue;
2827 		}
2828 	}
2829 	return (NULL);
2830 }
2831 
2832 static void *
2833 slab_alloc_item(uma_keg_t keg, uma_slab_t slab)
2834 {
2835 	uma_domain_t dom;
2836 	void *item;
2837 	uint8_t freei;
2838 
2839 	MPASS(keg == slab->us_keg);
2840 	mtx_assert(&keg->uk_lock, MA_OWNED);
2841 
2842 	freei = BIT_FFS(SLAB_SETSIZE, &slab->us_free) - 1;
2843 	BIT_CLR(SLAB_SETSIZE, freei, &slab->us_free);
2844 	item = slab->us_data + (keg->uk_rsize * freei);
2845 	slab->us_freecount--;
2846 	keg->uk_free--;
2847 
2848 	/* Move this slab to the full list */
2849 	if (slab->us_freecount == 0) {
2850 		LIST_REMOVE(slab, us_link);
2851 		dom = &keg->uk_domain[slab->us_domain];
2852 		LIST_INSERT_HEAD(&dom->ud_full_slab, slab, us_link);
2853 	}
2854 
2855 	return (item);
2856 }
2857 
2858 static int
2859 zone_import(uma_zone_t zone, void **bucket, int max, int domain, int flags)
2860 {
2861 	uma_slab_t slab;
2862 	uma_keg_t keg;
2863 #ifdef NUMA
2864 	int stripe;
2865 #endif
2866 	int i;
2867 
2868 	slab = NULL;
2869 	keg = NULL;
2870 	/* Try to keep the buckets totally full */
2871 	for (i = 0; i < max; ) {
2872 		if ((slab = zone->uz_slab(zone, keg, domain, flags)) == NULL)
2873 			break;
2874 		keg = slab->us_keg;
2875 #ifdef NUMA
2876 		stripe = howmany(max, vm_ndomains);
2877 #endif
2878 		while (slab->us_freecount && i < max) {
2879 			bucket[i++] = slab_alloc_item(keg, slab);
2880 			if (keg->uk_free <= keg->uk_reserve)
2881 				break;
2882 #ifdef NUMA
2883 			/*
2884 			 * If the zone is striped we pick a new slab for every
2885 			 * N allocations.  Eliminating this conditional will
2886 			 * instead pick a new domain for each bucket rather
2887 			 * than stripe within each bucket.  The current option
2888 			 * produces more fragmentation and requires more cpu
2889 			 * time but yields better distribution.
2890 			 */
2891 			if ((zone->uz_flags & UMA_ZONE_NUMA) == 0 &&
2892 			    vm_ndomains > 1 && --stripe == 0)
2893 				break;
2894 #endif
2895 		}
2896 		/* Don't block if we allocated any successfully. */
2897 		flags &= ~M_WAITOK;
2898 		flags |= M_NOWAIT;
2899 	}
2900 	if (slab != NULL)
2901 		KEG_UNLOCK(keg);
2902 
2903 	return i;
2904 }
2905 
2906 static uma_bucket_t
2907 zone_alloc_bucket(uma_zone_t zone, void *udata, int domain, int flags)
2908 {
2909 	uma_bucket_t bucket;
2910 	int max;
2911 
2912 	/* Don't wait for buckets, preserve caller's NOVM setting. */
2913 	bucket = bucket_alloc(zone, udata, M_NOWAIT | (flags & M_NOVM));
2914 	if (bucket == NULL)
2915 		return (NULL);
2916 
2917 	max = MIN(bucket->ub_entries, zone->uz_count);
2918 	bucket->ub_cnt = zone->uz_import(zone->uz_arg, bucket->ub_bucket,
2919 	    max, domain, flags);
2920 
2921 	/*
2922 	 * Initialize the memory if necessary.
2923 	 */
2924 	if (bucket->ub_cnt != 0 && zone->uz_init != NULL) {
2925 		int i;
2926 
2927 		for (i = 0; i < bucket->ub_cnt; i++)
2928 			if (zone->uz_init(bucket->ub_bucket[i], zone->uz_size,
2929 			    flags) != 0)
2930 				break;
2931 		/*
2932 		 * If we couldn't initialize the whole bucket, put the
2933 		 * rest back onto the freelist.
2934 		 */
2935 		if (i != bucket->ub_cnt) {
2936 			zone->uz_release(zone->uz_arg, &bucket->ub_bucket[i],
2937 			    bucket->ub_cnt - i);
2938 #ifdef INVARIANTS
2939 			bzero(&bucket->ub_bucket[i],
2940 			    sizeof(void *) * (bucket->ub_cnt - i));
2941 #endif
2942 			bucket->ub_cnt = i;
2943 		}
2944 	}
2945 
2946 	if (bucket->ub_cnt == 0) {
2947 		bucket_free(zone, bucket, udata);
2948 		atomic_add_long(&zone->uz_fails, 1);
2949 		return (NULL);
2950 	}
2951 
2952 	return (bucket);
2953 }
2954 
2955 /*
2956  * Allocates a single item from a zone.
2957  *
2958  * Arguments
2959  *	zone   The zone to alloc for.
2960  *	udata  The data to be passed to the constructor.
2961  *	domain The domain to allocate from or UMA_ANYDOMAIN.
2962  *	flags  M_WAITOK, M_NOWAIT, M_ZERO.
2963  *
2964  * Returns
2965  *	NULL if there is no memory and M_NOWAIT is set
2966  *	An item if successful
2967  */
2968 
2969 static void *
2970 zone_alloc_item(uma_zone_t zone, void *udata, int domain, int flags)
2971 {
2972 	void *item;
2973 #ifdef INVARIANTS
2974 	bool skipdbg;
2975 #endif
2976 
2977 	item = NULL;
2978 
2979 	if (zone->uz_import(zone->uz_arg, &item, 1, domain, flags) != 1)
2980 		goto fail;
2981 	atomic_add_long(&zone->uz_allocs, 1);
2982 
2983 #ifdef INVARIANTS
2984 	skipdbg = uma_dbg_zskip(zone, item);
2985 #endif
2986 	/*
2987 	 * We have to call both the zone's init (not the keg's init)
2988 	 * and the zone's ctor.  This is because the item is going from
2989 	 * a keg slab directly to the user, and the user is expecting it
2990 	 * to be both zone-init'd as well as zone-ctor'd.
2991 	 */
2992 	if (zone->uz_init != NULL) {
2993 		if (zone->uz_init(item, zone->uz_size, flags) != 0) {
2994 			zone_free_item(zone, item, udata, SKIP_FINI);
2995 			goto fail;
2996 		}
2997 	}
2998 	if (zone->uz_ctor != NULL &&
2999 #ifdef INVARIANTS
3000 	    (!skipdbg || zone->uz_ctor != trash_ctor ||
3001 	    zone->uz_dtor != trash_dtor) &&
3002 #endif
3003 	    zone->uz_ctor(item, zone->uz_size, udata, flags) != 0) {
3004 		zone_free_item(zone, item, udata, SKIP_DTOR);
3005 		goto fail;
3006 	}
3007 #ifdef INVARIANTS
3008 	if (!skipdbg)
3009 		uma_dbg_alloc(zone, NULL, item);
3010 #endif
3011 	if (flags & M_ZERO)
3012 		uma_zero_item(item, zone);
3013 
3014 	CTR3(KTR_UMA, "zone_alloc_item item %p from %s(%p)", item,
3015 	    zone->uz_name, zone);
3016 
3017 	return (item);
3018 
3019 fail:
3020 	CTR2(KTR_UMA, "zone_alloc_item failed from %s(%p)",
3021 	    zone->uz_name, zone);
3022 	atomic_add_long(&zone->uz_fails, 1);
3023 	return (NULL);
3024 }
3025 
3026 /* See uma.h */
3027 void
3028 uma_zfree_arg(uma_zone_t zone, void *item, void *udata)
3029 {
3030 	uma_cache_t cache;
3031 	uma_bucket_t bucket;
3032 	uma_zone_domain_t zdom;
3033 	int cpu, domain, lockfail;
3034 #ifdef INVARIANTS
3035 	bool skipdbg;
3036 #endif
3037 
3038 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
3039 	random_harvest_fast_uma(&zone, sizeof(zone), 1, RANDOM_UMA);
3040 
3041 	CTR2(KTR_UMA, "uma_zfree_arg thread %x zone %s", curthread,
3042 	    zone->uz_name);
3043 
3044 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
3045 	    ("uma_zfree_arg: called with spinlock or critical section held"));
3046 
3047         /* uma_zfree(..., NULL) does nothing, to match free(9). */
3048         if (item == NULL)
3049                 return;
3050 #ifdef DEBUG_MEMGUARD
3051 	if (is_memguard_addr(item)) {
3052 		if (zone->uz_dtor != NULL)
3053 			zone->uz_dtor(item, zone->uz_size, udata);
3054 		if (zone->uz_fini != NULL)
3055 			zone->uz_fini(item, zone->uz_size);
3056 		memguard_free(item);
3057 		return;
3058 	}
3059 #endif
3060 #ifdef INVARIANTS
3061 	skipdbg = uma_dbg_zskip(zone, item);
3062 	if (skipdbg == false) {
3063 		if (zone->uz_flags & UMA_ZONE_MALLOC)
3064 			uma_dbg_free(zone, udata, item);
3065 		else
3066 			uma_dbg_free(zone, NULL, item);
3067 	}
3068 	if (zone->uz_dtor != NULL && (!skipdbg ||
3069 	    zone->uz_dtor != trash_dtor || zone->uz_ctor != trash_ctor))
3070 #else
3071 	if (zone->uz_dtor != NULL)
3072 #endif
3073 		zone->uz_dtor(item, zone->uz_size, udata);
3074 
3075 	/*
3076 	 * The race here is acceptable.  If we miss it we'll just have to wait
3077 	 * a little longer for the limits to be reset.
3078 	 */
3079 	if (zone->uz_flags & UMA_ZFLAG_FULL)
3080 		goto zfree_item;
3081 
3082 	/*
3083 	 * If possible, free to the per-CPU cache.  There are two
3084 	 * requirements for safe access to the per-CPU cache: (1) the thread
3085 	 * accessing the cache must not be preempted or yield during access,
3086 	 * and (2) the thread must not migrate CPUs without switching which
3087 	 * cache it accesses.  We rely on a critical section to prevent
3088 	 * preemption and migration.  We release the critical section in
3089 	 * order to acquire the zone mutex if we are unable to free to the
3090 	 * current cache; when we re-acquire the critical section, we must
3091 	 * detect and handle migration if it has occurred.
3092 	 */
3093 zfree_restart:
3094 	critical_enter();
3095 	cpu = curcpu;
3096 	cache = &zone->uz_cpu[cpu];
3097 
3098 zfree_start:
3099 	/*
3100 	 * Try to free into the allocbucket first to give LIFO ordering
3101 	 * for cache-hot datastructures.  Spill over into the freebucket
3102 	 * if necessary.  Alloc will swap them if one runs dry.
3103 	 */
3104 	bucket = cache->uc_allocbucket;
3105 	if (bucket == NULL || bucket->ub_cnt >= bucket->ub_entries)
3106 		bucket = cache->uc_freebucket;
3107 	if (bucket != NULL && bucket->ub_cnt < bucket->ub_entries) {
3108 		KASSERT(bucket->ub_bucket[bucket->ub_cnt] == NULL,
3109 		    ("uma_zfree: Freeing to non free bucket index."));
3110 		bucket->ub_bucket[bucket->ub_cnt] = item;
3111 		bucket->ub_cnt++;
3112 		cache->uc_frees++;
3113 		critical_exit();
3114 		return;
3115 	}
3116 
3117 	/*
3118 	 * We must go back the zone, which requires acquiring the zone lock,
3119 	 * which in turn means we must release and re-acquire the critical
3120 	 * section.  Since the critical section is released, we may be
3121 	 * preempted or migrate.  As such, make sure not to maintain any
3122 	 * thread-local state specific to the cache from prior to releasing
3123 	 * the critical section.
3124 	 */
3125 	critical_exit();
3126 	if (zone->uz_count == 0 || bucketdisable)
3127 		goto zfree_item;
3128 
3129 	lockfail = 0;
3130 	if (ZONE_TRYLOCK(zone) == 0) {
3131 		/* Record contention to size the buckets. */
3132 		ZONE_LOCK(zone);
3133 		lockfail = 1;
3134 	}
3135 	critical_enter();
3136 	cpu = curcpu;
3137 	cache = &zone->uz_cpu[cpu];
3138 
3139 	/*
3140 	 * Since we have locked the zone we may as well send back our stats.
3141 	 */
3142 	atomic_add_long(&zone->uz_allocs, cache->uc_allocs);
3143 	atomic_add_long(&zone->uz_frees, cache->uc_frees);
3144 	cache->uc_allocs = 0;
3145 	cache->uc_frees = 0;
3146 
3147 	bucket = cache->uc_freebucket;
3148 	if (bucket != NULL && bucket->ub_cnt < bucket->ub_entries) {
3149 		ZONE_UNLOCK(zone);
3150 		goto zfree_start;
3151 	}
3152 	cache->uc_freebucket = NULL;
3153 	/* We are no longer associated with this CPU. */
3154 	critical_exit();
3155 
3156 	if ((zone->uz_flags & UMA_ZONE_NUMA) != 0)
3157 		domain = PCPU_GET(domain);
3158 	else
3159 		domain = 0;
3160 	zdom = &zone->uz_domain[0];
3161 
3162 	/* Can we throw this on the zone full list? */
3163 	if (bucket != NULL) {
3164 		CTR3(KTR_UMA,
3165 		    "uma_zfree: zone %s(%p) putting bucket %p on free list",
3166 		    zone->uz_name, zone, bucket);
3167 		/* ub_cnt is pointing to the last free item */
3168 		KASSERT(bucket->ub_cnt != 0,
3169 		    ("uma_zfree: Attempting to insert an empty bucket onto the full list.\n"));
3170 		if ((zone->uz_flags & UMA_ZONE_NOBUCKETCACHE) != 0) {
3171 			ZONE_UNLOCK(zone);
3172 			bucket_drain(zone, bucket);
3173 			bucket_free(zone, bucket, udata);
3174 			goto zfree_restart;
3175 		} else
3176 			LIST_INSERT_HEAD(&zdom->uzd_buckets, bucket, ub_link);
3177 	}
3178 
3179 	/*
3180 	 * We bump the uz count when the cache size is insufficient to
3181 	 * handle the working set.
3182 	 */
3183 	if (lockfail && zone->uz_count < BUCKET_MAX)
3184 		zone->uz_count++;
3185 	ZONE_UNLOCK(zone);
3186 
3187 	bucket = bucket_alloc(zone, udata, M_NOWAIT);
3188 	CTR3(KTR_UMA, "uma_zfree: zone %s(%p) allocated bucket %p",
3189 	    zone->uz_name, zone, bucket);
3190 	if (bucket) {
3191 		critical_enter();
3192 		cpu = curcpu;
3193 		cache = &zone->uz_cpu[cpu];
3194 		if (cache->uc_freebucket == NULL &&
3195 		    ((zone->uz_flags & UMA_ZONE_NUMA) == 0 ||
3196 		    domain == PCPU_GET(domain))) {
3197 			cache->uc_freebucket = bucket;
3198 			goto zfree_start;
3199 		}
3200 		/*
3201 		 * We lost the race, start over.  We have to drop our
3202 		 * critical section to free the bucket.
3203 		 */
3204 		critical_exit();
3205 		bucket_free(zone, bucket, udata);
3206 		goto zfree_restart;
3207 	}
3208 
3209 	/*
3210 	 * If nothing else caught this, we'll just do an internal free.
3211 	 */
3212 zfree_item:
3213 	zone_free_item(zone, item, udata, SKIP_DTOR);
3214 
3215 	return;
3216 }
3217 
3218 void
3219 uma_zfree_domain(uma_zone_t zone, void *item, void *udata)
3220 {
3221 
3222 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
3223 	random_harvest_fast_uma(&zone, sizeof(zone), 1, RANDOM_UMA);
3224 
3225 	CTR2(KTR_UMA, "uma_zfree_domain thread %x zone %s", curthread,
3226 	    zone->uz_name);
3227 
3228 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
3229 	    ("uma_zfree_domain: called with spinlock or critical section held"));
3230 
3231         /* uma_zfree(..., NULL) does nothing, to match free(9). */
3232         if (item == NULL)
3233                 return;
3234 	zone_free_item(zone, item, udata, SKIP_NONE);
3235 }
3236 
3237 static void
3238 slab_free_item(uma_keg_t keg, uma_slab_t slab, void *item)
3239 {
3240 	uma_domain_t dom;
3241 	uint8_t freei;
3242 
3243 	mtx_assert(&keg->uk_lock, MA_OWNED);
3244 	MPASS(keg == slab->us_keg);
3245 
3246 	dom = &keg->uk_domain[slab->us_domain];
3247 
3248 	/* Do we need to remove from any lists? */
3249 	if (slab->us_freecount+1 == keg->uk_ipers) {
3250 		LIST_REMOVE(slab, us_link);
3251 		LIST_INSERT_HEAD(&dom->ud_free_slab, slab, us_link);
3252 	} else if (slab->us_freecount == 0) {
3253 		LIST_REMOVE(slab, us_link);
3254 		LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
3255 	}
3256 
3257 	/* Slab management. */
3258 	freei = ((uintptr_t)item - (uintptr_t)slab->us_data) / keg->uk_rsize;
3259 	BIT_SET(SLAB_SETSIZE, freei, &slab->us_free);
3260 	slab->us_freecount++;
3261 
3262 	/* Keg statistics. */
3263 	keg->uk_free++;
3264 }
3265 
3266 static void
3267 zone_release(uma_zone_t zone, void **bucket, int cnt)
3268 {
3269 	void *item;
3270 	uma_slab_t slab;
3271 	uma_keg_t keg;
3272 	uint8_t *mem;
3273 	int clearfull;
3274 	int i;
3275 
3276 	clearfull = 0;
3277 	keg = zone_first_keg(zone);
3278 	KEG_LOCK(keg);
3279 	for (i = 0; i < cnt; i++) {
3280 		item = bucket[i];
3281 		if (!(zone->uz_flags & UMA_ZONE_VTOSLAB)) {
3282 			mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
3283 			if (zone->uz_flags & UMA_ZONE_HASH) {
3284 				slab = hash_sfind(&keg->uk_hash, mem);
3285 			} else {
3286 				mem += keg->uk_pgoff;
3287 				slab = (uma_slab_t)mem;
3288 			}
3289 		} else {
3290 			slab = vtoslab((vm_offset_t)item);
3291 			if (slab->us_keg != keg) {
3292 				KEG_UNLOCK(keg);
3293 				keg = slab->us_keg;
3294 				KEG_LOCK(keg);
3295 			}
3296 		}
3297 		slab_free_item(keg, slab, item);
3298 		if (keg->uk_flags & UMA_ZFLAG_FULL) {
3299 			if (keg->uk_pages < keg->uk_maxpages) {
3300 				keg->uk_flags &= ~UMA_ZFLAG_FULL;
3301 				clearfull = 1;
3302 			}
3303 
3304 			/*
3305 			 * We can handle one more allocation. Since we're
3306 			 * clearing ZFLAG_FULL, wake up all procs blocked
3307 			 * on pages. This should be uncommon, so keeping this
3308 			 * simple for now (rather than adding count of blocked
3309 			 * threads etc).
3310 			 */
3311 			wakeup(keg);
3312 		}
3313 	}
3314 	KEG_UNLOCK(keg);
3315 	if (clearfull) {
3316 		ZONE_LOCK(zone);
3317 		zone->uz_flags &= ~UMA_ZFLAG_FULL;
3318 		wakeup(zone);
3319 		ZONE_UNLOCK(zone);
3320 	}
3321 
3322 }
3323 
3324 /*
3325  * Frees a single item to any zone.
3326  *
3327  * Arguments:
3328  *	zone   The zone to free to
3329  *	item   The item we're freeing
3330  *	udata  User supplied data for the dtor
3331  *	skip   Skip dtors and finis
3332  */
3333 static void
3334 zone_free_item(uma_zone_t zone, void *item, void *udata, enum zfreeskip skip)
3335 {
3336 #ifdef INVARIANTS
3337 	bool skipdbg;
3338 
3339 	skipdbg = uma_dbg_zskip(zone, item);
3340 	if (skip == SKIP_NONE && !skipdbg) {
3341 		if (zone->uz_flags & UMA_ZONE_MALLOC)
3342 			uma_dbg_free(zone, udata, item);
3343 		else
3344 			uma_dbg_free(zone, NULL, item);
3345 	}
3346 
3347 	if (skip < SKIP_DTOR && zone->uz_dtor != NULL &&
3348 	    (!skipdbg || zone->uz_dtor != trash_dtor ||
3349 	    zone->uz_ctor != trash_ctor))
3350 #else
3351 	if (skip < SKIP_DTOR && zone->uz_dtor != NULL)
3352 #endif
3353 		zone->uz_dtor(item, zone->uz_size, udata);
3354 
3355 	if (skip < SKIP_FINI && zone->uz_fini)
3356 		zone->uz_fini(item, zone->uz_size);
3357 
3358 	atomic_add_long(&zone->uz_frees, 1);
3359 	zone->uz_release(zone->uz_arg, &item, 1);
3360 }
3361 
3362 /* See uma.h */
3363 int
3364 uma_zone_set_max(uma_zone_t zone, int nitems)
3365 {
3366 	uma_keg_t keg;
3367 
3368 	keg = zone_first_keg(zone);
3369 	if (keg == NULL)
3370 		return (0);
3371 	KEG_LOCK(keg);
3372 	keg->uk_maxpages = (nitems / keg->uk_ipers) * keg->uk_ppera;
3373 	if (keg->uk_maxpages * keg->uk_ipers < nitems)
3374 		keg->uk_maxpages += keg->uk_ppera;
3375 	nitems = (keg->uk_maxpages / keg->uk_ppera) * keg->uk_ipers;
3376 	KEG_UNLOCK(keg);
3377 
3378 	return (nitems);
3379 }
3380 
3381 /* See uma.h */
3382 int
3383 uma_zone_get_max(uma_zone_t zone)
3384 {
3385 	int nitems;
3386 	uma_keg_t keg;
3387 
3388 	keg = zone_first_keg(zone);
3389 	if (keg == NULL)
3390 		return (0);
3391 	KEG_LOCK(keg);
3392 	nitems = (keg->uk_maxpages / keg->uk_ppera) * keg->uk_ipers;
3393 	KEG_UNLOCK(keg);
3394 
3395 	return (nitems);
3396 }
3397 
3398 /* See uma.h */
3399 void
3400 uma_zone_set_warning(uma_zone_t zone, const char *warning)
3401 {
3402 
3403 	ZONE_LOCK(zone);
3404 	zone->uz_warning = warning;
3405 	ZONE_UNLOCK(zone);
3406 }
3407 
3408 /* See uma.h */
3409 void
3410 uma_zone_set_maxaction(uma_zone_t zone, uma_maxaction_t maxaction)
3411 {
3412 
3413 	ZONE_LOCK(zone);
3414 	TASK_INIT(&zone->uz_maxaction, 0, (task_fn_t *)maxaction, zone);
3415 	ZONE_UNLOCK(zone);
3416 }
3417 
3418 /* See uma.h */
3419 int
3420 uma_zone_get_cur(uma_zone_t zone)
3421 {
3422 	int64_t nitems;
3423 	u_int i;
3424 
3425 	ZONE_LOCK(zone);
3426 	nitems = zone->uz_allocs - zone->uz_frees;
3427 	CPU_FOREACH(i) {
3428 		/*
3429 		 * See the comment in sysctl_vm_zone_stats() regarding the
3430 		 * safety of accessing the per-cpu caches. With the zone lock
3431 		 * held, it is safe, but can potentially result in stale data.
3432 		 */
3433 		nitems += zone->uz_cpu[i].uc_allocs -
3434 		    zone->uz_cpu[i].uc_frees;
3435 	}
3436 	ZONE_UNLOCK(zone);
3437 
3438 	return (nitems < 0 ? 0 : nitems);
3439 }
3440 
3441 /* See uma.h */
3442 void
3443 uma_zone_set_init(uma_zone_t zone, uma_init uminit)
3444 {
3445 	uma_keg_t keg;
3446 
3447 	keg = zone_first_keg(zone);
3448 	KASSERT(keg != NULL, ("uma_zone_set_init: Invalid zone type"));
3449 	KEG_LOCK(keg);
3450 	KASSERT(keg->uk_pages == 0,
3451 	    ("uma_zone_set_init on non-empty keg"));
3452 	keg->uk_init = uminit;
3453 	KEG_UNLOCK(keg);
3454 }
3455 
3456 /* See uma.h */
3457 void
3458 uma_zone_set_fini(uma_zone_t zone, uma_fini fini)
3459 {
3460 	uma_keg_t keg;
3461 
3462 	keg = zone_first_keg(zone);
3463 	KASSERT(keg != NULL, ("uma_zone_set_fini: Invalid zone type"));
3464 	KEG_LOCK(keg);
3465 	KASSERT(keg->uk_pages == 0,
3466 	    ("uma_zone_set_fini on non-empty keg"));
3467 	keg->uk_fini = fini;
3468 	KEG_UNLOCK(keg);
3469 }
3470 
3471 /* See uma.h */
3472 void
3473 uma_zone_set_zinit(uma_zone_t zone, uma_init zinit)
3474 {
3475 
3476 	ZONE_LOCK(zone);
3477 	KASSERT(zone_first_keg(zone)->uk_pages == 0,
3478 	    ("uma_zone_set_zinit on non-empty keg"));
3479 	zone->uz_init = zinit;
3480 	ZONE_UNLOCK(zone);
3481 }
3482 
3483 /* See uma.h */
3484 void
3485 uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini)
3486 {
3487 
3488 	ZONE_LOCK(zone);
3489 	KASSERT(zone_first_keg(zone)->uk_pages == 0,
3490 	    ("uma_zone_set_zfini on non-empty keg"));
3491 	zone->uz_fini = zfini;
3492 	ZONE_UNLOCK(zone);
3493 }
3494 
3495 /* See uma.h */
3496 /* XXX uk_freef is not actually used with the zone locked */
3497 void
3498 uma_zone_set_freef(uma_zone_t zone, uma_free freef)
3499 {
3500 	uma_keg_t keg;
3501 
3502 	keg = zone_first_keg(zone);
3503 	KASSERT(keg != NULL, ("uma_zone_set_freef: Invalid zone type"));
3504 	KEG_LOCK(keg);
3505 	keg->uk_freef = freef;
3506 	KEG_UNLOCK(keg);
3507 }
3508 
3509 /* See uma.h */
3510 /* XXX uk_allocf is not actually used with the zone locked */
3511 void
3512 uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf)
3513 {
3514 	uma_keg_t keg;
3515 
3516 	keg = zone_first_keg(zone);
3517 	KEG_LOCK(keg);
3518 	keg->uk_allocf = allocf;
3519 	KEG_UNLOCK(keg);
3520 }
3521 
3522 /* See uma.h */
3523 void
3524 uma_zone_reserve(uma_zone_t zone, int items)
3525 {
3526 	uma_keg_t keg;
3527 
3528 	keg = zone_first_keg(zone);
3529 	if (keg == NULL)
3530 		return;
3531 	KEG_LOCK(keg);
3532 	keg->uk_reserve = items;
3533 	KEG_UNLOCK(keg);
3534 
3535 	return;
3536 }
3537 
3538 /* See uma.h */
3539 int
3540 uma_zone_reserve_kva(uma_zone_t zone, int count)
3541 {
3542 	uma_keg_t keg;
3543 	vm_offset_t kva;
3544 	u_int pages;
3545 
3546 	keg = zone_first_keg(zone);
3547 	if (keg == NULL)
3548 		return (0);
3549 	pages = count / keg->uk_ipers;
3550 
3551 	if (pages * keg->uk_ipers < count)
3552 		pages++;
3553 	pages *= keg->uk_ppera;
3554 
3555 #ifdef UMA_MD_SMALL_ALLOC
3556 	if (keg->uk_ppera > 1) {
3557 #else
3558 	if (1) {
3559 #endif
3560 		kva = kva_alloc((vm_size_t)pages * PAGE_SIZE);
3561 		if (kva == 0)
3562 			return (0);
3563 	} else
3564 		kva = 0;
3565 	KEG_LOCK(keg);
3566 	keg->uk_kva = kva;
3567 	keg->uk_offset = 0;
3568 	keg->uk_maxpages = pages;
3569 #ifdef UMA_MD_SMALL_ALLOC
3570 	keg->uk_allocf = (keg->uk_ppera > 1) ? noobj_alloc : uma_small_alloc;
3571 #else
3572 	keg->uk_allocf = noobj_alloc;
3573 #endif
3574 	keg->uk_flags |= UMA_ZONE_NOFREE;
3575 	KEG_UNLOCK(keg);
3576 
3577 	return (1);
3578 }
3579 
3580 /* See uma.h */
3581 void
3582 uma_prealloc(uma_zone_t zone, int items)
3583 {
3584 	uma_domain_t dom;
3585 	uma_slab_t slab;
3586 	uma_keg_t keg;
3587 	int domain, slabs;
3588 
3589 	keg = zone_first_keg(zone);
3590 	if (keg == NULL)
3591 		return;
3592 	KEG_LOCK(keg);
3593 	slabs = items / keg->uk_ipers;
3594 	domain = 0;
3595 	if (slabs * keg->uk_ipers < items)
3596 		slabs++;
3597 	while (slabs > 0) {
3598 		slab = keg_alloc_slab(keg, zone, domain, M_WAITOK);
3599 		if (slab == NULL)
3600 			break;
3601 		MPASS(slab->us_keg == keg);
3602 		dom = &keg->uk_domain[slab->us_domain];
3603 		LIST_INSERT_HEAD(&dom->ud_free_slab, slab, us_link);
3604 		slabs--;
3605 		domain = (domain + 1) % vm_ndomains;
3606 	}
3607 	KEG_UNLOCK(keg);
3608 }
3609 
3610 /* See uma.h */
3611 static void
3612 uma_reclaim_locked(bool kmem_danger)
3613 {
3614 
3615 	CTR0(KTR_UMA, "UMA: vm asked us to release pages!");
3616 	sx_assert(&uma_drain_lock, SA_XLOCKED);
3617 	bucket_enable();
3618 	zone_foreach(zone_drain);
3619 	if (vm_page_count_min() || kmem_danger) {
3620 		cache_drain_safe(NULL);
3621 		zone_foreach(zone_drain);
3622 	}
3623 	/*
3624 	 * Some slabs may have been freed but this zone will be visited early
3625 	 * we visit again so that we can free pages that are empty once other
3626 	 * zones are drained.  We have to do the same for buckets.
3627 	 */
3628 	zone_drain(slabzone);
3629 	bucket_zone_drain();
3630 }
3631 
3632 void
3633 uma_reclaim(void)
3634 {
3635 
3636 	sx_xlock(&uma_drain_lock);
3637 	uma_reclaim_locked(false);
3638 	sx_xunlock(&uma_drain_lock);
3639 }
3640 
3641 static volatile int uma_reclaim_needed;
3642 
3643 void
3644 uma_reclaim_wakeup(void)
3645 {
3646 
3647 	if (atomic_fetchadd_int(&uma_reclaim_needed, 1) == 0)
3648 		wakeup(uma_reclaim);
3649 }
3650 
3651 void
3652 uma_reclaim_worker(void *arg __unused)
3653 {
3654 
3655 	for (;;) {
3656 		sx_xlock(&uma_drain_lock);
3657 		while (atomic_load_int(&uma_reclaim_needed) == 0)
3658 			sx_sleep(uma_reclaim, &uma_drain_lock, PVM, "umarcl",
3659 			    hz);
3660 		sx_xunlock(&uma_drain_lock);
3661 		EVENTHANDLER_INVOKE(vm_lowmem, VM_LOW_KMEM);
3662 		sx_xlock(&uma_drain_lock);
3663 		uma_reclaim_locked(true);
3664 		atomic_store_int(&uma_reclaim_needed, 0);
3665 		sx_xunlock(&uma_drain_lock);
3666 		/* Don't fire more than once per-second. */
3667 		pause("umarclslp", hz);
3668 	}
3669 }
3670 
3671 /* See uma.h */
3672 int
3673 uma_zone_exhausted(uma_zone_t zone)
3674 {
3675 	int full;
3676 
3677 	ZONE_LOCK(zone);
3678 	full = (zone->uz_flags & UMA_ZFLAG_FULL);
3679 	ZONE_UNLOCK(zone);
3680 	return (full);
3681 }
3682 
3683 int
3684 uma_zone_exhausted_nolock(uma_zone_t zone)
3685 {
3686 	return (zone->uz_flags & UMA_ZFLAG_FULL);
3687 }
3688 
3689 void *
3690 uma_large_malloc_domain(vm_size_t size, int domain, int wait)
3691 {
3692 	struct vmem *arena;
3693 	vm_offset_t addr;
3694 	uma_slab_t slab;
3695 
3696 #if VM_NRESERVLEVEL > 0
3697 	if (__predict_true((wait & M_EXEC) == 0))
3698 		arena = kernel_arena;
3699 	else
3700 		arena = kernel_rwx_arena;
3701 #else
3702 	arena = kernel_arena;
3703 #endif
3704 
3705 	slab = zone_alloc_item(slabzone, NULL, domain, wait);
3706 	if (slab == NULL)
3707 		return (NULL);
3708 	if (domain == UMA_ANYDOMAIN)
3709 		addr = kmem_malloc(arena, size, wait);
3710 	else
3711 		addr = kmem_malloc_domain(arena, domain, size, wait);
3712 	if (addr != 0) {
3713 		vsetslab(addr, slab);
3714 		slab->us_data = (void *)addr;
3715 		slab->us_flags = UMA_SLAB_KERNEL | UMA_SLAB_MALLOC;
3716 #if VM_NRESERVLEVEL > 0
3717 		if (__predict_false(arena == kernel_rwx_arena))
3718 			slab->us_flags |= UMA_SLAB_KRWX;
3719 #endif
3720 		slab->us_size = size;
3721 		slab->us_domain = vm_phys_domain(PHYS_TO_VM_PAGE(
3722 		    pmap_kextract(addr)));
3723 		uma_total_inc(size);
3724 	} else {
3725 		zone_free_item(slabzone, slab, NULL, SKIP_NONE);
3726 	}
3727 
3728 	return ((void *)addr);
3729 }
3730 
3731 void *
3732 uma_large_malloc(vm_size_t size, int wait)
3733 {
3734 
3735 	return uma_large_malloc_domain(size, UMA_ANYDOMAIN, wait);
3736 }
3737 
3738 void
3739 uma_large_free(uma_slab_t slab)
3740 {
3741 	struct vmem *arena;
3742 
3743 	KASSERT((slab->us_flags & UMA_SLAB_KERNEL) != 0,
3744 	    ("uma_large_free:  Memory not allocated with uma_large_malloc."));
3745 #if VM_NRESERVLEVEL > 0
3746 	if (__predict_true((slab->us_flags & UMA_SLAB_KRWX) == 0))
3747 		arena = kernel_arena;
3748 	else
3749 		arena = kernel_rwx_arena;
3750 #else
3751 	arena = kernel_arena;
3752 #endif
3753 	kmem_free(arena, (vm_offset_t)slab->us_data, slab->us_size);
3754 	uma_total_dec(slab->us_size);
3755 	zone_free_item(slabzone, slab, NULL, SKIP_NONE);
3756 }
3757 
3758 static void
3759 uma_zero_item(void *item, uma_zone_t zone)
3760 {
3761 
3762 	bzero(item, zone->uz_size);
3763 }
3764 
3765 unsigned long
3766 uma_limit(void)
3767 {
3768 
3769 	return (uma_kmem_limit);
3770 }
3771 
3772 void
3773 uma_set_limit(unsigned long limit)
3774 {
3775 
3776 	uma_kmem_limit = limit;
3777 }
3778 
3779 unsigned long
3780 uma_size(void)
3781 {
3782 
3783 	return (uma_kmem_total);
3784 }
3785 
3786 long
3787 uma_avail(void)
3788 {
3789 
3790 	return (uma_kmem_limit - uma_kmem_total);
3791 }
3792 
3793 void
3794 uma_print_stats(void)
3795 {
3796 	zone_foreach(uma_print_zone);
3797 }
3798 
3799 static void
3800 slab_print(uma_slab_t slab)
3801 {
3802 	printf("slab: keg %p, data %p, freecount %d\n",
3803 		slab->us_keg, slab->us_data, slab->us_freecount);
3804 }
3805 
3806 static void
3807 cache_print(uma_cache_t cache)
3808 {
3809 	printf("alloc: %p(%d), free: %p(%d)\n",
3810 		cache->uc_allocbucket,
3811 		cache->uc_allocbucket?cache->uc_allocbucket->ub_cnt:0,
3812 		cache->uc_freebucket,
3813 		cache->uc_freebucket?cache->uc_freebucket->ub_cnt:0);
3814 }
3815 
3816 static void
3817 uma_print_keg(uma_keg_t keg)
3818 {
3819 	uma_domain_t dom;
3820 	uma_slab_t slab;
3821 	int i;
3822 
3823 	printf("keg: %s(%p) size %d(%d) flags %#x ipers %d ppera %d "
3824 	    "out %d free %d limit %d\n",
3825 	    keg->uk_name, keg, keg->uk_size, keg->uk_rsize, keg->uk_flags,
3826 	    keg->uk_ipers, keg->uk_ppera,
3827 	    (keg->uk_pages / keg->uk_ppera) * keg->uk_ipers - keg->uk_free,
3828 	    keg->uk_free, (keg->uk_maxpages / keg->uk_ppera) * keg->uk_ipers);
3829 	for (i = 0; i < vm_ndomains; i++) {
3830 		dom = &keg->uk_domain[i];
3831 		printf("Part slabs:\n");
3832 		LIST_FOREACH(slab, &dom->ud_part_slab, us_link)
3833 			slab_print(slab);
3834 		printf("Free slabs:\n");
3835 		LIST_FOREACH(slab, &dom->ud_free_slab, us_link)
3836 			slab_print(slab);
3837 		printf("Full slabs:\n");
3838 		LIST_FOREACH(slab, &dom->ud_full_slab, us_link)
3839 			slab_print(slab);
3840 	}
3841 }
3842 
3843 void
3844 uma_print_zone(uma_zone_t zone)
3845 {
3846 	uma_cache_t cache;
3847 	uma_klink_t kl;
3848 	int i;
3849 
3850 	printf("zone: %s(%p) size %d flags %#x\n",
3851 	    zone->uz_name, zone, zone->uz_size, zone->uz_flags);
3852 	LIST_FOREACH(kl, &zone->uz_kegs, kl_link)
3853 		uma_print_keg(kl->kl_keg);
3854 	CPU_FOREACH(i) {
3855 		cache = &zone->uz_cpu[i];
3856 		printf("CPU %d Cache:\n", i);
3857 		cache_print(cache);
3858 	}
3859 }
3860 
3861 #ifdef DDB
3862 /*
3863  * Generate statistics across both the zone and its per-cpu cache's.  Return
3864  * desired statistics if the pointer is non-NULL for that statistic.
3865  *
3866  * Note: does not update the zone statistics, as it can't safely clear the
3867  * per-CPU cache statistic.
3868  *
3869  * XXXRW: Following the uc_allocbucket and uc_freebucket pointers here isn't
3870  * safe from off-CPU; we should modify the caches to track this information
3871  * directly so that we don't have to.
3872  */
3873 static void
3874 uma_zone_sumstat(uma_zone_t z, int *cachefreep, uint64_t *allocsp,
3875     uint64_t *freesp, uint64_t *sleepsp)
3876 {
3877 	uma_cache_t cache;
3878 	uint64_t allocs, frees, sleeps;
3879 	int cachefree, cpu;
3880 
3881 	allocs = frees = sleeps = 0;
3882 	cachefree = 0;
3883 	CPU_FOREACH(cpu) {
3884 		cache = &z->uz_cpu[cpu];
3885 		if (cache->uc_allocbucket != NULL)
3886 			cachefree += cache->uc_allocbucket->ub_cnt;
3887 		if (cache->uc_freebucket != NULL)
3888 			cachefree += cache->uc_freebucket->ub_cnt;
3889 		allocs += cache->uc_allocs;
3890 		frees += cache->uc_frees;
3891 	}
3892 	allocs += z->uz_allocs;
3893 	frees += z->uz_frees;
3894 	sleeps += z->uz_sleeps;
3895 	if (cachefreep != NULL)
3896 		*cachefreep = cachefree;
3897 	if (allocsp != NULL)
3898 		*allocsp = allocs;
3899 	if (freesp != NULL)
3900 		*freesp = frees;
3901 	if (sleepsp != NULL)
3902 		*sleepsp = sleeps;
3903 }
3904 #endif /* DDB */
3905 
3906 static int
3907 sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS)
3908 {
3909 	uma_keg_t kz;
3910 	uma_zone_t z;
3911 	int count;
3912 
3913 	count = 0;
3914 	rw_rlock(&uma_rwlock);
3915 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3916 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
3917 			count++;
3918 	}
3919 	rw_runlock(&uma_rwlock);
3920 	return (sysctl_handle_int(oidp, &count, 0, req));
3921 }
3922 
3923 static int
3924 sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS)
3925 {
3926 	struct uma_stream_header ush;
3927 	struct uma_type_header uth;
3928 	struct uma_percpu_stat *ups;
3929 	uma_bucket_t bucket;
3930 	uma_zone_domain_t zdom;
3931 	struct sbuf sbuf;
3932 	uma_cache_t cache;
3933 	uma_klink_t kl;
3934 	uma_keg_t kz;
3935 	uma_zone_t z;
3936 	uma_keg_t k;
3937 	int count, error, i;
3938 
3939 	error = sysctl_wire_old_buffer(req, 0);
3940 	if (error != 0)
3941 		return (error);
3942 	sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
3943 	sbuf_clear_flags(&sbuf, SBUF_INCLUDENUL);
3944 	ups = malloc((mp_maxid + 1) * sizeof(*ups), M_TEMP, M_WAITOK);
3945 
3946 	count = 0;
3947 	rw_rlock(&uma_rwlock);
3948 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3949 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
3950 			count++;
3951 	}
3952 
3953 	/*
3954 	 * Insert stream header.
3955 	 */
3956 	bzero(&ush, sizeof(ush));
3957 	ush.ush_version = UMA_STREAM_VERSION;
3958 	ush.ush_maxcpus = (mp_maxid + 1);
3959 	ush.ush_count = count;
3960 	(void)sbuf_bcat(&sbuf, &ush, sizeof(ush));
3961 
3962 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3963 		LIST_FOREACH(z, &kz->uk_zones, uz_link) {
3964 			bzero(&uth, sizeof(uth));
3965 			ZONE_LOCK(z);
3966 			strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
3967 			uth.uth_align = kz->uk_align;
3968 			uth.uth_size = kz->uk_size;
3969 			uth.uth_rsize = kz->uk_rsize;
3970 			LIST_FOREACH(kl, &z->uz_kegs, kl_link) {
3971 				k = kl->kl_keg;
3972 				uth.uth_maxpages += k->uk_maxpages;
3973 				uth.uth_pages += k->uk_pages;
3974 				uth.uth_keg_free += k->uk_free;
3975 				uth.uth_limit = (k->uk_maxpages / k->uk_ppera)
3976 				    * k->uk_ipers;
3977 			}
3978 
3979 			/*
3980 			 * A zone is secondary is it is not the first entry
3981 			 * on the keg's zone list.
3982 			 */
3983 			if ((z->uz_flags & UMA_ZONE_SECONDARY) &&
3984 			    (LIST_FIRST(&kz->uk_zones) != z))
3985 				uth.uth_zone_flags = UTH_ZONE_SECONDARY;
3986 
3987 			for (i = 0; i < vm_ndomains; i++) {
3988 				zdom = &z->uz_domain[i];
3989 				LIST_FOREACH(bucket, &zdom->uzd_buckets,
3990 				    ub_link)
3991 					uth.uth_zone_free += bucket->ub_cnt;
3992 			}
3993 			uth.uth_allocs = z->uz_allocs;
3994 			uth.uth_frees = z->uz_frees;
3995 			uth.uth_fails = z->uz_fails;
3996 			uth.uth_sleeps = z->uz_sleeps;
3997 			/*
3998 			 * While it is not normally safe to access the cache
3999 			 * bucket pointers while not on the CPU that owns the
4000 			 * cache, we only allow the pointers to be exchanged
4001 			 * without the zone lock held, not invalidated, so
4002 			 * accept the possible race associated with bucket
4003 			 * exchange during monitoring.
4004 			 */
4005 			for (i = 0; i < mp_maxid + 1; i++) {
4006 				bzero(&ups[i], sizeof(*ups));
4007 				if (kz->uk_flags & UMA_ZFLAG_INTERNAL ||
4008 				    CPU_ABSENT(i))
4009 					continue;
4010 				cache = &z->uz_cpu[i];
4011 				if (cache->uc_allocbucket != NULL)
4012 					ups[i].ups_cache_free +=
4013 					    cache->uc_allocbucket->ub_cnt;
4014 				if (cache->uc_freebucket != NULL)
4015 					ups[i].ups_cache_free +=
4016 					    cache->uc_freebucket->ub_cnt;
4017 				ups[i].ups_allocs = cache->uc_allocs;
4018 				ups[i].ups_frees = cache->uc_frees;
4019 			}
4020 			ZONE_UNLOCK(z);
4021 			(void)sbuf_bcat(&sbuf, &uth, sizeof(uth));
4022 			for (i = 0; i < mp_maxid + 1; i++)
4023 				(void)sbuf_bcat(&sbuf, &ups[i], sizeof(ups[i]));
4024 		}
4025 	}
4026 	rw_runlock(&uma_rwlock);
4027 	error = sbuf_finish(&sbuf);
4028 	sbuf_delete(&sbuf);
4029 	free(ups, M_TEMP);
4030 	return (error);
4031 }
4032 
4033 int
4034 sysctl_handle_uma_zone_max(SYSCTL_HANDLER_ARGS)
4035 {
4036 	uma_zone_t zone = *(uma_zone_t *)arg1;
4037 	int error, max;
4038 
4039 	max = uma_zone_get_max(zone);
4040 	error = sysctl_handle_int(oidp, &max, 0, req);
4041 	if (error || !req->newptr)
4042 		return (error);
4043 
4044 	uma_zone_set_max(zone, max);
4045 
4046 	return (0);
4047 }
4048 
4049 int
4050 sysctl_handle_uma_zone_cur(SYSCTL_HANDLER_ARGS)
4051 {
4052 	uma_zone_t zone = *(uma_zone_t *)arg1;
4053 	int cur;
4054 
4055 	cur = uma_zone_get_cur(zone);
4056 	return (sysctl_handle_int(oidp, &cur, 0, req));
4057 }
4058 
4059 #ifdef INVARIANTS
4060 static uma_slab_t
4061 uma_dbg_getslab(uma_zone_t zone, void *item)
4062 {
4063 	uma_slab_t slab;
4064 	uma_keg_t keg;
4065 	uint8_t *mem;
4066 
4067 	mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
4068 	if (zone->uz_flags & UMA_ZONE_VTOSLAB) {
4069 		slab = vtoslab((vm_offset_t)mem);
4070 	} else {
4071 		/*
4072 		 * It is safe to return the slab here even though the
4073 		 * zone is unlocked because the item's allocation state
4074 		 * essentially holds a reference.
4075 		 */
4076 		ZONE_LOCK(zone);
4077 		keg = LIST_FIRST(&zone->uz_kegs)->kl_keg;
4078 		if (keg->uk_flags & UMA_ZONE_HASH)
4079 			slab = hash_sfind(&keg->uk_hash, mem);
4080 		else
4081 			slab = (uma_slab_t)(mem + keg->uk_pgoff);
4082 		ZONE_UNLOCK(zone);
4083 	}
4084 
4085 	return (slab);
4086 }
4087 
4088 static bool
4089 uma_dbg_zskip(uma_zone_t zone, void *mem)
4090 {
4091 	uma_keg_t keg;
4092 
4093 	if ((keg = zone_first_keg(zone)) == NULL)
4094 		return (true);
4095 
4096 	return (uma_dbg_kskip(keg, mem));
4097 }
4098 
4099 static bool
4100 uma_dbg_kskip(uma_keg_t keg, void *mem)
4101 {
4102 	uintptr_t idx;
4103 
4104 	if (dbg_divisor == 0)
4105 		return (true);
4106 
4107 	if (dbg_divisor == 1)
4108 		return (false);
4109 
4110 	idx = (uintptr_t)mem >> PAGE_SHIFT;
4111 	if (keg->uk_ipers > 1) {
4112 		idx *= keg->uk_ipers;
4113 		idx += ((uintptr_t)mem & PAGE_MASK) / keg->uk_rsize;
4114 	}
4115 
4116 	if ((idx / dbg_divisor) * dbg_divisor != idx) {
4117 		counter_u64_add(uma_skip_cnt, 1);
4118 		return (true);
4119 	}
4120 	counter_u64_add(uma_dbg_cnt, 1);
4121 
4122 	return (false);
4123 }
4124 
4125 /*
4126  * Set up the slab's freei data such that uma_dbg_free can function.
4127  *
4128  */
4129 static void
4130 uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item)
4131 {
4132 	uma_keg_t keg;
4133 	int freei;
4134 
4135 	if (slab == NULL) {
4136 		slab = uma_dbg_getslab(zone, item);
4137 		if (slab == NULL)
4138 			panic("uma: item %p did not belong to zone %s\n",
4139 			    item, zone->uz_name);
4140 	}
4141 	keg = slab->us_keg;
4142 	freei = ((uintptr_t)item - (uintptr_t)slab->us_data) / keg->uk_rsize;
4143 
4144 	if (BIT_ISSET(SLAB_SETSIZE, freei, &slab->us_debugfree))
4145 		panic("Duplicate alloc of %p from zone %p(%s) slab %p(%d)\n",
4146 		    item, zone, zone->uz_name, slab, freei);
4147 	BIT_SET_ATOMIC(SLAB_SETSIZE, freei, &slab->us_debugfree);
4148 
4149 	return;
4150 }
4151 
4152 /*
4153  * Verifies freed addresses.  Checks for alignment, valid slab membership
4154  * and duplicate frees.
4155  *
4156  */
4157 static void
4158 uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item)
4159 {
4160 	uma_keg_t keg;
4161 	int freei;
4162 
4163 	if (slab == NULL) {
4164 		slab = uma_dbg_getslab(zone, item);
4165 		if (slab == NULL)
4166 			panic("uma: Freed item %p did not belong to zone %s\n",
4167 			    item, zone->uz_name);
4168 	}
4169 	keg = slab->us_keg;
4170 	freei = ((uintptr_t)item - (uintptr_t)slab->us_data) / keg->uk_rsize;
4171 
4172 	if (freei >= keg->uk_ipers)
4173 		panic("Invalid free of %p from zone %p(%s) slab %p(%d)\n",
4174 		    item, zone, zone->uz_name, slab, freei);
4175 
4176 	if (((freei * keg->uk_rsize) + slab->us_data) != item)
4177 		panic("Unaligned free of %p from zone %p(%s) slab %p(%d)\n",
4178 		    item, zone, zone->uz_name, slab, freei);
4179 
4180 	if (!BIT_ISSET(SLAB_SETSIZE, freei, &slab->us_debugfree))
4181 		panic("Duplicate free of %p from zone %p(%s) slab %p(%d)\n",
4182 		    item, zone, zone->uz_name, slab, freei);
4183 
4184 	BIT_CLR_ATOMIC(SLAB_SETSIZE, freei, &slab->us_debugfree);
4185 }
4186 #endif /* INVARIANTS */
4187 
4188 #ifdef DDB
4189 DB_SHOW_COMMAND(uma, db_show_uma)
4190 {
4191 	uma_bucket_t bucket;
4192 	uma_keg_t kz;
4193 	uma_zone_t z;
4194 	uma_zone_domain_t zdom;
4195 	uint64_t allocs, frees, sleeps;
4196 	int cachefree, i;
4197 
4198 	db_printf("%18s %8s %8s %8s %12s %8s %8s\n", "Zone", "Size", "Used",
4199 	    "Free", "Requests", "Sleeps", "Bucket");
4200 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
4201 		LIST_FOREACH(z, &kz->uk_zones, uz_link) {
4202 			if (kz->uk_flags & UMA_ZFLAG_INTERNAL) {
4203 				allocs = z->uz_allocs;
4204 				frees = z->uz_frees;
4205 				sleeps = z->uz_sleeps;
4206 				cachefree = 0;
4207 			} else
4208 				uma_zone_sumstat(z, &cachefree, &allocs,
4209 				    &frees, &sleeps);
4210 			if (!((z->uz_flags & UMA_ZONE_SECONDARY) &&
4211 			    (LIST_FIRST(&kz->uk_zones) != z)))
4212 				cachefree += kz->uk_free;
4213 			for (i = 0; i < vm_ndomains; i++) {
4214 				zdom = &z->uz_domain[i];
4215 				LIST_FOREACH(bucket, &zdom->uzd_buckets,
4216 				    ub_link)
4217 					cachefree += bucket->ub_cnt;
4218 			}
4219 			db_printf("%18s %8ju %8jd %8d %12ju %8ju %8u\n",
4220 			    z->uz_name, (uintmax_t)kz->uk_size,
4221 			    (intmax_t)(allocs - frees), cachefree,
4222 			    (uintmax_t)allocs, sleeps, z->uz_count);
4223 			if (db_pager_quit)
4224 				return;
4225 		}
4226 	}
4227 }
4228 
4229 DB_SHOW_COMMAND(umacache, db_show_umacache)
4230 {
4231 	uma_bucket_t bucket;
4232 	uma_zone_t z;
4233 	uma_zone_domain_t zdom;
4234 	uint64_t allocs, frees;
4235 	int cachefree, i;
4236 
4237 	db_printf("%18s %8s %8s %8s %12s %8s\n", "Zone", "Size", "Used", "Free",
4238 	    "Requests", "Bucket");
4239 	LIST_FOREACH(z, &uma_cachezones, uz_link) {
4240 		uma_zone_sumstat(z, &cachefree, &allocs, &frees, NULL);
4241 		for (i = 0; i < vm_ndomains; i++) {
4242 			zdom = &z->uz_domain[i];
4243 			LIST_FOREACH(bucket, &zdom->uzd_buckets, ub_link)
4244 				cachefree += bucket->ub_cnt;
4245 		}
4246 		db_printf("%18s %8ju %8jd %8d %12ju %8u\n",
4247 		    z->uz_name, (uintmax_t)z->uz_size,
4248 		    (intmax_t)(allocs - frees), cachefree,
4249 		    (uintmax_t)allocs, z->uz_count);
4250 		if (db_pager_quit)
4251 			return;
4252 	}
4253 }
4254 #endif	/* DDB */
4255