1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2002-2019 Jeffrey Roberson <jeff@FreeBSD.org>
5 * Copyright (c) 2004, 2005 Bosko Milekic <bmilekic@FreeBSD.org>
6 * Copyright (c) 2004-2006 Robert N. M. Watson
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice unmodified, this list of conditions, and the following
14 *    disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31/*
32 * uma_core.c  Implementation of the Universal Memory allocator
33 *
34 * This allocator is intended to replace the multitude of similar object caches
35 * in the standard FreeBSD kernel.  The intent is to be flexible as well as
36 * efficient.  A primary design goal is to return unused memory to the rest of
37 * the system.  This will make the system as a whole more flexible due to the
38 * ability to move memory to subsystems which most need it instead of leaving
39 * pools of reserved memory unused.
40 *
41 * The basic ideas stem from similar slab/zone based allocators whose algorithms
42 * are well known.
43 *
44 */
45
46/*
47 * TODO:
48 *	- Improve memory usage for large allocations
49 *	- Investigate cache size adjustments
50 */
51
52#include <sys/cdefs.h>
53__FBSDID("$FreeBSD$");
54
55#include "opt_ddb.h"
56#include "opt_param.h"
57#include "opt_vm.h"
58
59#include <sys/param.h>
60#include <sys/systm.h>
61#include <sys/bitset.h>
62#include <sys/domainset.h>
63#include <sys/eventhandler.h>
64#include <sys/kernel.h>
65#include <sys/types.h>
66#include <sys/limits.h>
67#include <sys/queue.h>
68#include <sys/malloc.h>
69#include <sys/ktr.h>
70#include <sys/lock.h>
71#include <sys/sysctl.h>
72#include <sys/mutex.h>
73#include <sys/proc.h>
74#include <sys/random.h>
75#include <sys/rwlock.h>
76#include <sys/sbuf.h>
77#include <sys/sched.h>
78#include <sys/sleepqueue.h>
79#include <sys/smp.h>
80#include <sys/smr.h>
81#include <sys/taskqueue.h>
82#include <sys/vmmeter.h>
83
84#include <vm/vm.h>
85#include <vm/vm_param.h>
86#include <vm/vm_domainset.h>
87#include <vm/vm_object.h>
88#include <vm/vm_page.h>
89#include <vm/vm_pageout.h>
90#include <vm/vm_phys.h>
91#include <vm/vm_pagequeue.h>
92#include <vm/vm_map.h>
93#include <vm/vm_kern.h>
94#include <vm/vm_extern.h>
95#include <vm/vm_dumpset.h>
96#include <vm/uma.h>
97#include <vm/uma_int.h>
98#include <vm/uma_dbg.h>
99
100#include <ddb/ddb.h>
101
102#ifdef DEBUG_MEMGUARD
103#include <vm/memguard.h>
104#endif
105
106#include <machine/md_var.h>
107
108#ifdef INVARIANTS
109#define	UMA_ALWAYS_CTORDTOR	1
110#else
111#define	UMA_ALWAYS_CTORDTOR	0
112#endif
113
114/*
115 * This is the zone and keg from which all zones are spawned.
116 */
117static uma_zone_t kegs;
118static uma_zone_t zones;
119
120/*
121 * On INVARIANTS builds, the slab contains a second bitset of the same size,
122 * "dbg_bits", which is laid out immediately after us_free.
123 */
124#ifdef INVARIANTS
125#define	SLAB_BITSETS	2
126#else
127#define	SLAB_BITSETS	1
128#endif
129
130/*
131 * These are the two zones from which all offpage uma_slab_ts are allocated.
132 *
133 * One zone is for slab headers that can represent a larger number of items,
134 * making the slabs themselves more efficient, and the other zone is for
135 * headers that are smaller and represent fewer items, making the headers more
136 * efficient.
137 */
138#define	SLABZONE_SIZE(setsize)					\
139    (sizeof(struct uma_hash_slab) + BITSET_SIZE(setsize) * SLAB_BITSETS)
140#define	SLABZONE0_SETSIZE	(PAGE_SIZE / 16)
141#define	SLABZONE1_SETSIZE	SLAB_MAX_SETSIZE
142#define	SLABZONE0_SIZE	SLABZONE_SIZE(SLABZONE0_SETSIZE)
143#define	SLABZONE1_SIZE	SLABZONE_SIZE(SLABZONE1_SETSIZE)
144static uma_zone_t slabzones[2];
145
146/*
147 * The initial hash tables come out of this zone so they can be allocated
148 * prior to malloc coming up.
149 */
150static uma_zone_t hashzone;
151
152/* The boot-time adjusted value for cache line alignment. */
153int uma_align_cache = 64 - 1;
154
155static MALLOC_DEFINE(M_UMAHASH, "UMAHash", "UMA Hash Buckets");
156static MALLOC_DEFINE(M_UMA, "UMA", "UMA Misc");
157
158/*
159 * Are we allowed to allocate buckets?
160 */
161static int bucketdisable = 1;
162
163/* Linked list of all kegs in the system */
164static LIST_HEAD(,uma_keg) uma_kegs = LIST_HEAD_INITIALIZER(uma_kegs);
165
166/* Linked list of all cache-only zones in the system */
167static LIST_HEAD(,uma_zone) uma_cachezones =
168    LIST_HEAD_INITIALIZER(uma_cachezones);
169
170/*
171 * Mutex for global lists: uma_kegs, uma_cachezones, and the per-keg list of
172 * zones.
173 */
174static struct rwlock_padalign __exclusive_cache_line uma_rwlock;
175
176static struct sx uma_reclaim_lock;
177
178/*
179 * First available virual address for boot time allocations.
180 */
181static vm_offset_t bootstart;
182static vm_offset_t bootmem;
183
184/*
185 * kmem soft limit, initialized by uma_set_limit().  Ensure that early
186 * allocations don't trigger a wakeup of the reclaim thread.
187 */
188unsigned long uma_kmem_limit = LONG_MAX;
189SYSCTL_ULONG(_vm, OID_AUTO, uma_kmem_limit, CTLFLAG_RD, &uma_kmem_limit, 0,
190    "UMA kernel memory soft limit");
191unsigned long uma_kmem_total;
192SYSCTL_ULONG(_vm, OID_AUTO, uma_kmem_total, CTLFLAG_RD, &uma_kmem_total, 0,
193    "UMA kernel memory usage");
194
195/* Is the VM done starting up? */
196static enum {
197	BOOT_COLD,
198	BOOT_KVA,
199	BOOT_PCPU,
200	BOOT_RUNNING,
201	BOOT_SHUTDOWN,
202} booted = BOOT_COLD;
203
204/*
205 * This is the handle used to schedule events that need to happen
206 * outside of the allocation fast path.
207 */
208static struct callout uma_callout;
209#define	UMA_TIMEOUT	20		/* Seconds for callout interval. */
210
211/*
212 * This structure is passed as the zone ctor arg so that I don't have to create
213 * a special allocation function just for zones.
214 */
215struct uma_zctor_args {
216	const char *name;
217	size_t size;
218	uma_ctor ctor;
219	uma_dtor dtor;
220	uma_init uminit;
221	uma_fini fini;
222	uma_import import;
223	uma_release release;
224	void *arg;
225	uma_keg_t keg;
226	int align;
227	uint32_t flags;
228};
229
230struct uma_kctor_args {
231	uma_zone_t zone;
232	size_t size;
233	uma_init uminit;
234	uma_fini fini;
235	int align;
236	uint32_t flags;
237};
238
239struct uma_bucket_zone {
240	uma_zone_t	ubz_zone;
241	const char	*ubz_name;
242	int		ubz_entries;	/* Number of items it can hold. */
243	int		ubz_maxsize;	/* Maximum allocation size per-item. */
244};
245
246/*
247 * Compute the actual number of bucket entries to pack them in power
248 * of two sizes for more efficient space utilization.
249 */
250#define	BUCKET_SIZE(n)						\
251    (((sizeof(void *) * (n)) - sizeof(struct uma_bucket)) / sizeof(void *))
252
253#define	BUCKET_MAX	BUCKET_SIZE(256)
254
255struct uma_bucket_zone bucket_zones[] = {
256	/* Literal bucket sizes. */
257	{ NULL, "2 Bucket", 2, 4096 },
258	{ NULL, "4 Bucket", 4, 3072 },
259	{ NULL, "8 Bucket", 8, 2048 },
260	{ NULL, "16 Bucket", 16, 1024 },
261	/* Rounded down power of 2 sizes for efficiency. */
262	{ NULL, "32 Bucket", BUCKET_SIZE(32), 512 },
263	{ NULL, "64 Bucket", BUCKET_SIZE(64), 256 },
264	{ NULL, "128 Bucket", BUCKET_SIZE(128), 128 },
265	{ NULL, "256 Bucket", BUCKET_SIZE(256), 64 },
266	{ NULL, NULL, 0}
267};
268
269/*
270 * Flags and enumerations to be passed to internal functions.
271 */
272enum zfreeskip {
273	SKIP_NONE =	0,
274	SKIP_CNT =	0x00000001,
275	SKIP_DTOR =	0x00010000,
276	SKIP_FINI =	0x00020000,
277};
278
279/* Prototypes.. */
280
281void	uma_startup1(vm_offset_t);
282void	uma_startup2(void);
283
284static void *noobj_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
285static void *page_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
286static void *pcpu_page_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
287static void *startup_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
288static void *contig_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
289static void page_free(void *, vm_size_t, uint8_t);
290static void pcpu_page_free(void *, vm_size_t, uint8_t);
291static uma_slab_t keg_alloc_slab(uma_keg_t, uma_zone_t, int, int, int);
292static void cache_drain(uma_zone_t);
293static void bucket_drain(uma_zone_t, uma_bucket_t);
294static void bucket_cache_reclaim(uma_zone_t zone, bool, int);
295static bool bucket_cache_reclaim_domain(uma_zone_t, bool, bool, int);
296static int keg_ctor(void *, int, void *, int);
297static void keg_dtor(void *, int, void *);
298static void keg_drain(uma_keg_t keg, int domain);
299static int zone_ctor(void *, int, void *, int);
300static void zone_dtor(void *, int, void *);
301static inline void item_dtor(uma_zone_t zone, void *item, int size,
302    void *udata, enum zfreeskip skip);
303static int zero_init(void *, int, int);
304static void zone_free_bucket(uma_zone_t zone, uma_bucket_t bucket, void *udata,
305    int itemdomain, bool ws);
306static void zone_foreach(void (*zfunc)(uma_zone_t, void *), void *);
307static void zone_foreach_unlocked(void (*zfunc)(uma_zone_t, void *), void *);
308static void zone_timeout(uma_zone_t zone, void *);
309static int hash_alloc(struct uma_hash *, u_int);
310static int hash_expand(struct uma_hash *, struct uma_hash *);
311static void hash_free(struct uma_hash *hash);
312static void uma_timeout(void *);
313static void uma_shutdown(void);
314static void *zone_alloc_item(uma_zone_t, void *, int, int);
315static void zone_free_item(uma_zone_t, void *, void *, enum zfreeskip);
316static int zone_alloc_limit(uma_zone_t zone, int count, int flags);
317static void zone_free_limit(uma_zone_t zone, int count);
318static void bucket_enable(void);
319static void bucket_init(void);
320static uma_bucket_t bucket_alloc(uma_zone_t zone, void *, int);
321static void bucket_free(uma_zone_t zone, uma_bucket_t, void *);
322static void bucket_zone_drain(int domain);
323static uma_bucket_t zone_alloc_bucket(uma_zone_t, void *, int, int);
324static void *slab_alloc_item(uma_keg_t keg, uma_slab_t slab);
325static void slab_free_item(uma_zone_t zone, uma_slab_t slab, void *item);
326static uma_keg_t uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit,
327    uma_fini fini, int align, uint32_t flags);
328static int zone_import(void *, void **, int, int, int);
329static void zone_release(void *, void **, int);
330static bool cache_alloc(uma_zone_t, uma_cache_t, void *, int);
331static bool cache_free(uma_zone_t, uma_cache_t, void *, void *, int);
332
333static int sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS);
334static int sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS);
335static int sysctl_handle_uma_zone_allocs(SYSCTL_HANDLER_ARGS);
336static int sysctl_handle_uma_zone_frees(SYSCTL_HANDLER_ARGS);
337static int sysctl_handle_uma_zone_flags(SYSCTL_HANDLER_ARGS);
338static int sysctl_handle_uma_slab_efficiency(SYSCTL_HANDLER_ARGS);
339static int sysctl_handle_uma_zone_items(SYSCTL_HANDLER_ARGS);
340
341static uint64_t uma_zone_get_allocs(uma_zone_t zone);
342
343static SYSCTL_NODE(_vm, OID_AUTO, debug, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
344    "Memory allocation debugging");
345
346#ifdef INVARIANTS
347static uint64_t uma_keg_get_allocs(uma_keg_t zone);
348static inline struct noslabbits *slab_dbg_bits(uma_slab_t slab, uma_keg_t keg);
349
350static bool uma_dbg_kskip(uma_keg_t keg, void *mem);
351static bool uma_dbg_zskip(uma_zone_t zone, void *mem);
352static void uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item);
353static void uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item);
354
355static u_int dbg_divisor = 1;
356SYSCTL_UINT(_vm_debug, OID_AUTO, divisor,
357    CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &dbg_divisor, 0,
358    "Debug & thrash every this item in memory allocator");
359
360static counter_u64_t uma_dbg_cnt = EARLY_COUNTER;
361static counter_u64_t uma_skip_cnt = EARLY_COUNTER;
362SYSCTL_COUNTER_U64(_vm_debug, OID_AUTO, trashed, CTLFLAG_RD,
363    &uma_dbg_cnt, "memory items debugged");
364SYSCTL_COUNTER_U64(_vm_debug, OID_AUTO, skipped, CTLFLAG_RD,
365    &uma_skip_cnt, "memory items skipped, not debugged");
366#endif
367
368SYSCTL_NODE(_vm, OID_AUTO, uma, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
369    "Universal Memory Allocator");
370
371SYSCTL_PROC(_vm, OID_AUTO, zone_count, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLTYPE_INT,
372    0, 0, sysctl_vm_zone_count, "I", "Number of UMA zones");
373
374SYSCTL_PROC(_vm, OID_AUTO, zone_stats, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLTYPE_STRUCT,
375    0, 0, sysctl_vm_zone_stats, "s,struct uma_type_header", "Zone Stats");
376
377static int zone_warnings = 1;
378SYSCTL_INT(_vm, OID_AUTO, zone_warnings, CTLFLAG_RWTUN, &zone_warnings, 0,
379    "Warn when UMA zones becomes full");
380
381static int multipage_slabs = 1;
382TUNABLE_INT("vm.debug.uma_multipage_slabs", &multipage_slabs);
383SYSCTL_INT(_vm_debug, OID_AUTO, uma_multipage_slabs,
384    CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &multipage_slabs, 0,
385    "UMA may choose larger slab sizes for better efficiency");
386
387/*
388 * Select the slab zone for an offpage slab with the given maximum item count.
389 */
390static inline uma_zone_t
391slabzone(int ipers)
392{
393
394	return (slabzones[ipers > SLABZONE0_SETSIZE]);
395}
396
397/*
398 * This routine checks to see whether or not it's safe to enable buckets.
399 */
400static void
401bucket_enable(void)
402{
403
404	KASSERT(booted >= BOOT_KVA, ("Bucket enable before init"));
405	bucketdisable = vm_page_count_min();
406}
407
408/*
409 * Initialize bucket_zones, the array of zones of buckets of various sizes.
410 *
411 * For each zone, calculate the memory required for each bucket, consisting
412 * of the header and an array of pointers.
413 */
414static void
415bucket_init(void)
416{
417	struct uma_bucket_zone *ubz;
418	int size;
419
420	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++) {
421		size = roundup(sizeof(struct uma_bucket), sizeof(void *));
422		size += sizeof(void *) * ubz->ubz_entries;
423		ubz->ubz_zone = uma_zcreate(ubz->ubz_name, size,
424		    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR,
425		    UMA_ZONE_MTXCLASS | UMA_ZFLAG_BUCKET |
426		    UMA_ZONE_FIRSTTOUCH);
427	}
428}
429
430/*
431 * Given a desired number of entries for a bucket, return the zone from which
432 * to allocate the bucket.
433 */
434static struct uma_bucket_zone *
435bucket_zone_lookup(int entries)
436{
437	struct uma_bucket_zone *ubz;
438
439	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
440		if (ubz->ubz_entries >= entries)
441			return (ubz);
442	ubz--;
443	return (ubz);
444}
445
446static int
447bucket_select(int size)
448{
449	struct uma_bucket_zone *ubz;
450
451	ubz = &bucket_zones[0];
452	if (size > ubz->ubz_maxsize)
453		return MAX((ubz->ubz_maxsize * ubz->ubz_entries) / size, 1);
454
455	for (; ubz->ubz_entries != 0; ubz++)
456		if (ubz->ubz_maxsize < size)
457			break;
458	ubz--;
459	return (ubz->ubz_entries);
460}
461
462static uma_bucket_t
463bucket_alloc(uma_zone_t zone, void *udata, int flags)
464{
465	struct uma_bucket_zone *ubz;
466	uma_bucket_t bucket;
467
468	/*
469	 * Don't allocate buckets early in boot.
470	 */
471	if (__predict_false(booted < BOOT_KVA))
472		return (NULL);
473
474	/*
475	 * To limit bucket recursion we store the original zone flags
476	 * in a cookie passed via zalloc_arg/zfree_arg.  This allows the
477	 * NOVM flag to persist even through deep recursions.  We also
478	 * store ZFLAG_BUCKET once we have recursed attempting to allocate
479	 * a bucket for a bucket zone so we do not allow infinite bucket
480	 * recursion.  This cookie will even persist to frees of unused
481	 * buckets via the allocation path or bucket allocations in the
482	 * free path.
483	 */
484	if ((zone->uz_flags & UMA_ZFLAG_BUCKET) == 0)
485		udata = (void *)(uintptr_t)zone->uz_flags;
486	else {
487		if ((uintptr_t)udata & UMA_ZFLAG_BUCKET)
488			return (NULL);
489		udata = (void *)((uintptr_t)udata | UMA_ZFLAG_BUCKET);
490	}
491	if (((uintptr_t)udata & UMA_ZONE_VM) != 0)
492		flags |= M_NOVM;
493	ubz = bucket_zone_lookup(atomic_load_16(&zone->uz_bucket_size));
494	if (ubz->ubz_zone == zone && (ubz + 1)->ubz_entries != 0)
495		ubz++;
496	bucket = uma_zalloc_arg(ubz->ubz_zone, udata, flags);
497	if (bucket) {
498#ifdef INVARIANTS
499		bzero(bucket->ub_bucket, sizeof(void *) * ubz->ubz_entries);
500#endif
501		bucket->ub_cnt = 0;
502		bucket->ub_entries = min(ubz->ubz_entries,
503		    zone->uz_bucket_size_max);
504		bucket->ub_seq = SMR_SEQ_INVALID;
505		CTR3(KTR_UMA, "bucket_alloc: zone %s(%p) allocated bucket %p",
506		    zone->uz_name, zone, bucket);
507	}
508
509	return (bucket);
510}
511
512static void
513bucket_free(uma_zone_t zone, uma_bucket_t bucket, void *udata)
514{
515	struct uma_bucket_zone *ubz;
516
517	if (bucket->ub_cnt != 0)
518		bucket_drain(zone, bucket);
519
520	KASSERT(bucket->ub_cnt == 0,
521	    ("bucket_free: Freeing a non free bucket."));
522	KASSERT(bucket->ub_seq == SMR_SEQ_INVALID,
523	    ("bucket_free: Freeing an SMR bucket."));
524	if ((zone->uz_flags & UMA_ZFLAG_BUCKET) == 0)
525		udata = (void *)(uintptr_t)zone->uz_flags;
526	ubz = bucket_zone_lookup(bucket->ub_entries);
527	uma_zfree_arg(ubz->ubz_zone, bucket, udata);
528}
529
530static void
531bucket_zone_drain(int domain)
532{
533	struct uma_bucket_zone *ubz;
534
535	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
536		uma_zone_reclaim_domain(ubz->ubz_zone, UMA_RECLAIM_DRAIN,
537		    domain);
538}
539
540/*
541 * Acquire the domain lock and record contention.
542 */
543static uma_zone_domain_t
544zone_domain_lock(uma_zone_t zone, int domain)
545{
546	uma_zone_domain_t zdom;
547	bool lockfail;
548
549	zdom = ZDOM_GET(zone, domain);
550	lockfail = false;
551	if (ZDOM_OWNED(zdom))
552		lockfail = true;
553	ZDOM_LOCK(zdom);
554	/* This is unsynchronized.  The counter does not need to be precise. */
555	if (lockfail && zone->uz_bucket_size < zone->uz_bucket_size_max)
556		zone->uz_bucket_size++;
557	return (zdom);
558}
559
560/*
561 * Search for the domain with the least cached items and return it if it
562 * is out of balance with the preferred domain.
563 */
564static __noinline int
565zone_domain_lowest(uma_zone_t zone, int pref)
566{
567	long least, nitems, prefitems;
568	int domain;
569	int i;
570
571	prefitems = least = LONG_MAX;
572	domain = 0;
573	for (i = 0; i < vm_ndomains; i++) {
574		nitems = ZDOM_GET(zone, i)->uzd_nitems;
575		if (nitems < least) {
576			domain = i;
577			least = nitems;
578		}
579		if (domain == pref)
580			prefitems = nitems;
581	}
582	if (prefitems < least * 2)
583		return (pref);
584
585	return (domain);
586}
587
588/*
589 * Search for the domain with the most cached items and return it or the
590 * preferred domain if it has enough to proceed.
591 */
592static __noinline int
593zone_domain_highest(uma_zone_t zone, int pref)
594{
595	long most, nitems;
596	int domain;
597	int i;
598
599	if (ZDOM_GET(zone, pref)->uzd_nitems > BUCKET_MAX)
600		return (pref);
601
602	most = 0;
603	domain = 0;
604	for (i = 0; i < vm_ndomains; i++) {
605		nitems = ZDOM_GET(zone, i)->uzd_nitems;
606		if (nitems > most) {
607			domain = i;
608			most = nitems;
609		}
610	}
611
612	return (domain);
613}
614
615/*
616 * Set the maximum imax value.
617 */
618static void
619zone_domain_imax_set(uma_zone_domain_t zdom, int nitems)
620{
621	long old;
622
623	old = zdom->uzd_imax;
624	do {
625		if (old >= nitems)
626			return;
627	} while (atomic_fcmpset_long(&zdom->uzd_imax, &old, nitems) == 0);
628
629	/*
630	 * We are at new maximum, so do the last WSS update for the old
631	 * bimin and prepare to measure next allocation batch.
632	 */
633	if (zdom->uzd_wss < old - zdom->uzd_bimin)
634		zdom->uzd_wss = old - zdom->uzd_bimin;
635	zdom->uzd_bimin = nitems;
636}
637
638/*
639 * Attempt to satisfy an allocation by retrieving a full bucket from one of the
640 * zone's caches.  If a bucket is found the zone is not locked on return.
641 */
642static uma_bucket_t
643zone_fetch_bucket(uma_zone_t zone, uma_zone_domain_t zdom, bool reclaim)
644{
645	uma_bucket_t bucket;
646	long cnt;
647	int i;
648	bool dtor = false;
649
650	ZDOM_LOCK_ASSERT(zdom);
651
652	if ((bucket = STAILQ_FIRST(&zdom->uzd_buckets)) == NULL)
653		return (NULL);
654
655	/* SMR Buckets can not be re-used until readers expire. */
656	if ((zone->uz_flags & UMA_ZONE_SMR) != 0 &&
657	    bucket->ub_seq != SMR_SEQ_INVALID) {
658		if (!smr_poll(zone->uz_smr, bucket->ub_seq, false))
659			return (NULL);
660		bucket->ub_seq = SMR_SEQ_INVALID;
661		dtor = (zone->uz_dtor != NULL) || UMA_ALWAYS_CTORDTOR;
662		if (STAILQ_NEXT(bucket, ub_link) != NULL)
663			zdom->uzd_seq = STAILQ_NEXT(bucket, ub_link)->ub_seq;
664	}
665	STAILQ_REMOVE_HEAD(&zdom->uzd_buckets, ub_link);
666
667	KASSERT(zdom->uzd_nitems >= bucket->ub_cnt,
668	    ("%s: item count underflow (%ld, %d)",
669	    __func__, zdom->uzd_nitems, bucket->ub_cnt));
670	KASSERT(bucket->ub_cnt > 0,
671	    ("%s: empty bucket in bucket cache", __func__));
672	zdom->uzd_nitems -= bucket->ub_cnt;
673
674	if (reclaim) {
675		/*
676		 * Shift the bounds of the current WSS interval to avoid
677		 * perturbing the estimates.
678		 */
679		cnt = lmin(zdom->uzd_bimin, bucket->ub_cnt);
680		atomic_subtract_long(&zdom->uzd_imax, cnt);
681		zdom->uzd_bimin -= cnt;
682		zdom->uzd_imin -= lmin(zdom->uzd_imin, bucket->ub_cnt);
683		if (zdom->uzd_limin >= bucket->ub_cnt) {
684			zdom->uzd_limin -= bucket->ub_cnt;
685		} else {
686			zdom->uzd_limin = 0;
687			zdom->uzd_timin = 0;
688		}
689	} else if (zdom->uzd_bimin > zdom->uzd_nitems) {
690		zdom->uzd_bimin = zdom->uzd_nitems;
691		if (zdom->uzd_imin > zdom->uzd_nitems)
692			zdom->uzd_imin = zdom->uzd_nitems;
693	}
694
695	ZDOM_UNLOCK(zdom);
696	if (dtor)
697		for (i = 0; i < bucket->ub_cnt; i++)
698			item_dtor(zone, bucket->ub_bucket[i], zone->uz_size,
699			    NULL, SKIP_NONE);
700
701	return (bucket);
702}
703
704/*
705 * Insert a full bucket into the specified cache.  The "ws" parameter indicates
706 * whether the bucket's contents should be counted as part of the zone's working
707 * set.  The bucket may be freed if it exceeds the bucket limit.
708 */
709static void
710zone_put_bucket(uma_zone_t zone, int domain, uma_bucket_t bucket, void *udata,
711    const bool ws)
712{
713	uma_zone_domain_t zdom;
714
715	/* We don't cache empty buckets.  This can happen after a reclaim. */
716	if (bucket->ub_cnt == 0)
717		goto out;
718	zdom = zone_domain_lock(zone, domain);
719
720	/*
721	 * Conditionally set the maximum number of items.
722	 */
723	zdom->uzd_nitems += bucket->ub_cnt;
724	if (__predict_true(zdom->uzd_nitems < zone->uz_bucket_max)) {
725		if (ws) {
726			zone_domain_imax_set(zdom, zdom->uzd_nitems);
727		} else {
728			/*
729			 * Shift the bounds of the current WSS interval to
730			 * avoid perturbing the estimates.
731			 */
732			atomic_add_long(&zdom->uzd_imax, bucket->ub_cnt);
733			zdom->uzd_imin += bucket->ub_cnt;
734			zdom->uzd_bimin += bucket->ub_cnt;
735			zdom->uzd_limin += bucket->ub_cnt;
736		}
737		if (STAILQ_EMPTY(&zdom->uzd_buckets))
738			zdom->uzd_seq = bucket->ub_seq;
739
740		/*
741		 * Try to promote reuse of recently used items.  For items
742		 * protected by SMR, try to defer reuse to minimize polling.
743		 */
744		if (bucket->ub_seq == SMR_SEQ_INVALID)
745			STAILQ_INSERT_HEAD(&zdom->uzd_buckets, bucket, ub_link);
746		else
747			STAILQ_INSERT_TAIL(&zdom->uzd_buckets, bucket, ub_link);
748		ZDOM_UNLOCK(zdom);
749		return;
750	}
751	zdom->uzd_nitems -= bucket->ub_cnt;
752	ZDOM_UNLOCK(zdom);
753out:
754	bucket_free(zone, bucket, udata);
755}
756
757/* Pops an item out of a per-cpu cache bucket. */
758static inline void *
759cache_bucket_pop(uma_cache_t cache, uma_cache_bucket_t bucket)
760{
761	void *item;
762
763	CRITICAL_ASSERT(curthread);
764
765	bucket->ucb_cnt--;
766	item = bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt];
767#ifdef INVARIANTS
768	bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt] = NULL;
769	KASSERT(item != NULL, ("uma_zalloc: Bucket pointer mangled."));
770#endif
771	cache->uc_allocs++;
772
773	return (item);
774}
775
776/* Pushes an item into a per-cpu cache bucket. */
777static inline void
778cache_bucket_push(uma_cache_t cache, uma_cache_bucket_t bucket, void *item)
779{
780
781	CRITICAL_ASSERT(curthread);
782	KASSERT(bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt] == NULL,
783	    ("uma_zfree: Freeing to non free bucket index."));
784
785	bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt] = item;
786	bucket->ucb_cnt++;
787	cache->uc_frees++;
788}
789
790/*
791 * Unload a UMA bucket from a per-cpu cache.
792 */
793static inline uma_bucket_t
794cache_bucket_unload(uma_cache_bucket_t bucket)
795{
796	uma_bucket_t b;
797
798	b = bucket->ucb_bucket;
799	if (b != NULL) {
800		MPASS(b->ub_entries == bucket->ucb_entries);
801		b->ub_cnt = bucket->ucb_cnt;
802		bucket->ucb_bucket = NULL;
803		bucket->ucb_entries = bucket->ucb_cnt = 0;
804	}
805
806	return (b);
807}
808
809static inline uma_bucket_t
810cache_bucket_unload_alloc(uma_cache_t cache)
811{
812
813	return (cache_bucket_unload(&cache->uc_allocbucket));
814}
815
816static inline uma_bucket_t
817cache_bucket_unload_free(uma_cache_t cache)
818{
819
820	return (cache_bucket_unload(&cache->uc_freebucket));
821}
822
823static inline uma_bucket_t
824cache_bucket_unload_cross(uma_cache_t cache)
825{
826
827	return (cache_bucket_unload(&cache->uc_crossbucket));
828}
829
830/*
831 * Load a bucket into a per-cpu cache bucket.
832 */
833static inline void
834cache_bucket_load(uma_cache_bucket_t bucket, uma_bucket_t b)
835{
836
837	CRITICAL_ASSERT(curthread);
838	MPASS(bucket->ucb_bucket == NULL);
839	MPASS(b->ub_seq == SMR_SEQ_INVALID);
840
841	bucket->ucb_bucket = b;
842	bucket->ucb_cnt = b->ub_cnt;
843	bucket->ucb_entries = b->ub_entries;
844}
845
846static inline void
847cache_bucket_load_alloc(uma_cache_t cache, uma_bucket_t b)
848{
849
850	cache_bucket_load(&cache->uc_allocbucket, b);
851}
852
853static inline void
854cache_bucket_load_free(uma_cache_t cache, uma_bucket_t b)
855{
856
857	cache_bucket_load(&cache->uc_freebucket, b);
858}
859
860#ifdef NUMA
861static inline void
862cache_bucket_load_cross(uma_cache_t cache, uma_bucket_t b)
863{
864
865	cache_bucket_load(&cache->uc_crossbucket, b);
866}
867#endif
868
869/*
870 * Copy and preserve ucb_spare.
871 */
872static inline void
873cache_bucket_copy(uma_cache_bucket_t b1, uma_cache_bucket_t b2)
874{
875
876	b1->ucb_bucket = b2->ucb_bucket;
877	b1->ucb_entries = b2->ucb_entries;
878	b1->ucb_cnt = b2->ucb_cnt;
879}
880
881/*
882 * Swap two cache buckets.
883 */
884static inline void
885cache_bucket_swap(uma_cache_bucket_t b1, uma_cache_bucket_t b2)
886{
887	struct uma_cache_bucket b3;
888
889	CRITICAL_ASSERT(curthread);
890
891	cache_bucket_copy(&b3, b1);
892	cache_bucket_copy(b1, b2);
893	cache_bucket_copy(b2, &b3);
894}
895
896/*
897 * Attempt to fetch a bucket from a zone on behalf of the current cpu cache.
898 */
899static uma_bucket_t
900cache_fetch_bucket(uma_zone_t zone, uma_cache_t cache, int domain)
901{
902	uma_zone_domain_t zdom;
903	uma_bucket_t bucket;
904
905	/*
906	 * Avoid the lock if possible.
907	 */
908	zdom = ZDOM_GET(zone, domain);
909	if (zdom->uzd_nitems == 0)
910		return (NULL);
911
912	if ((cache_uz_flags(cache) & UMA_ZONE_SMR) != 0 &&
913	    !smr_poll(zone->uz_smr, zdom->uzd_seq, false))
914		return (NULL);
915
916	/*
917	 * Check the zone's cache of buckets.
918	 */
919	zdom = zone_domain_lock(zone, domain);
920	if ((bucket = zone_fetch_bucket(zone, zdom, false)) != NULL)
921		return (bucket);
922	ZDOM_UNLOCK(zdom);
923
924	return (NULL);
925}
926
927static void
928zone_log_warning(uma_zone_t zone)
929{
930	static const struct timeval warninterval = { 300, 0 };
931
932	if (!zone_warnings || zone->uz_warning == NULL)
933		return;
934
935	if (ratecheck(&zone->uz_ratecheck, &warninterval))
936		printf("[zone: %s] %s\n", zone->uz_name, zone->uz_warning);
937}
938
939static inline void
940zone_maxaction(uma_zone_t zone)
941{
942
943	if (zone->uz_maxaction.ta_func != NULL)
944		taskqueue_enqueue(taskqueue_thread, &zone->uz_maxaction);
945}
946
947/*
948 * Routine called by timeout which is used to fire off some time interval
949 * based calculations.  (stats, hash size, etc.)
950 *
951 * Arguments:
952 *	arg   Unused
953 *
954 * Returns:
955 *	Nothing
956 */
957static void
958uma_timeout(void *unused)
959{
960	bucket_enable();
961	zone_foreach(zone_timeout, NULL);
962
963	/* Reschedule this event */
964	callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
965}
966
967/*
968 * Update the working set size estimates for the zone's bucket cache.
969 * The constants chosen here are somewhat arbitrary.
970 */
971static void
972zone_domain_update_wss(uma_zone_domain_t zdom)
973{
974	long m;
975
976	ZDOM_LOCK_ASSERT(zdom);
977	MPASS(zdom->uzd_imax >= zdom->uzd_nitems);
978	MPASS(zdom->uzd_nitems >= zdom->uzd_bimin);
979	MPASS(zdom->uzd_bimin >= zdom->uzd_imin);
980
981	/*
982	 * Estimate WSS as modified moving average of biggest allocation
983	 * batches for each period over few minutes (UMA_TIMEOUT of 20s).
984	 */
985	zdom->uzd_wss = lmax(zdom->uzd_wss * 3 / 4,
986	    zdom->uzd_imax - zdom->uzd_bimin);
987
988	/*
989	 * Estimate longtime minimum item count as a combination of recent
990	 * minimum item count, adjusted by WSS for safety, and the modified
991	 * moving average over the last several hours (UMA_TIMEOUT of 20s).
992	 * timin measures time since limin tried to go negative, that means
993	 * we were dangerously close to or got out of cache.
994	 */
995	m = zdom->uzd_imin - zdom->uzd_wss;
996	if (m >= 0) {
997		if (zdom->uzd_limin >= m)
998			zdom->uzd_limin = m;
999		else
1000			zdom->uzd_limin = (m + zdom->uzd_limin * 255) / 256;
1001		zdom->uzd_timin++;
1002	} else {
1003		zdom->uzd_limin = 0;
1004		zdom->uzd_timin = 0;
1005	}
1006
1007	/* To reduce period edge effects on WSS keep half of the imax. */
1008	atomic_subtract_long(&zdom->uzd_imax,
1009	    (zdom->uzd_imax - zdom->uzd_nitems + 1) / 2);
1010	zdom->uzd_imin = zdom->uzd_bimin = zdom->uzd_nitems;
1011}
1012
1013/*
1014 * Routine to perform timeout driven calculations.  This expands the
1015 * hashes and does per cpu statistics aggregation.
1016 *
1017 *  Returns nothing.
1018 */
1019static void
1020zone_timeout(uma_zone_t zone, void *unused)
1021{
1022	uma_keg_t keg;
1023	u_int slabs, pages;
1024
1025	if ((zone->uz_flags & UMA_ZFLAG_HASH) == 0)
1026		goto trim;
1027
1028	keg = zone->uz_keg;
1029
1030	/*
1031	 * Hash zones are non-numa by definition so the first domain
1032	 * is the only one present.
1033	 */
1034	KEG_LOCK(keg, 0);
1035	pages = keg->uk_domain[0].ud_pages;
1036
1037	/*
1038	 * Expand the keg hash table.
1039	 *
1040	 * This is done if the number of slabs is larger than the hash size.
1041	 * What I'm trying to do here is completely reduce collisions.  This
1042	 * may be a little aggressive.  Should I allow for two collisions max?
1043	 */
1044	if ((slabs = pages / keg->uk_ppera) > keg->uk_hash.uh_hashsize) {
1045		struct uma_hash newhash;
1046		struct uma_hash oldhash;
1047		int ret;
1048
1049		/*
1050		 * This is so involved because allocating and freeing
1051		 * while the keg lock is held will lead to deadlock.
1052		 * I have to do everything in stages and check for
1053		 * races.
1054		 */
1055		KEG_UNLOCK(keg, 0);
1056		ret = hash_alloc(&newhash, 1 << fls(slabs));
1057		KEG_LOCK(keg, 0);
1058		if (ret) {
1059			if (hash_expand(&keg->uk_hash, &newhash)) {
1060				oldhash = keg->uk_hash;
1061				keg->uk_hash = newhash;
1062			} else
1063				oldhash = newhash;
1064
1065			KEG_UNLOCK(keg, 0);
1066			hash_free(&oldhash);
1067			goto trim;
1068		}
1069	}
1070	KEG_UNLOCK(keg, 0);
1071
1072trim:
1073	/* Trim caches not used for a long time. */
1074	for (int i = 0; i < vm_ndomains; i++) {
1075		if (bucket_cache_reclaim_domain(zone, false, false, i) &&
1076		    (zone->uz_flags & UMA_ZFLAG_CACHE) == 0)
1077			keg_drain(zone->uz_keg, i);
1078	}
1079}
1080
1081/*
1082 * Allocate and zero fill the next sized hash table from the appropriate
1083 * backing store.
1084 *
1085 * Arguments:
1086 *	hash  A new hash structure with the old hash size in uh_hashsize
1087 *
1088 * Returns:
1089 *	1 on success and 0 on failure.
1090 */
1091static int
1092hash_alloc(struct uma_hash *hash, u_int size)
1093{
1094	size_t alloc;
1095
1096	KASSERT(powerof2(size), ("hash size must be power of 2"));
1097	if (size > UMA_HASH_SIZE_INIT)  {
1098		hash->uh_hashsize = size;
1099		alloc = sizeof(hash->uh_slab_hash[0]) * hash->uh_hashsize;
1100		hash->uh_slab_hash = malloc(alloc, M_UMAHASH, M_NOWAIT);
1101	} else {
1102		alloc = sizeof(hash->uh_slab_hash[0]) * UMA_HASH_SIZE_INIT;
1103		hash->uh_slab_hash = zone_alloc_item(hashzone, NULL,
1104		    UMA_ANYDOMAIN, M_WAITOK);
1105		hash->uh_hashsize = UMA_HASH_SIZE_INIT;
1106	}
1107	if (hash->uh_slab_hash) {
1108		bzero(hash->uh_slab_hash, alloc);
1109		hash->uh_hashmask = hash->uh_hashsize - 1;
1110		return (1);
1111	}
1112
1113	return (0);
1114}
1115
1116/*
1117 * Expands the hash table for HASH zones.  This is done from zone_timeout
1118 * to reduce collisions.  This must not be done in the regular allocation
1119 * path, otherwise, we can recurse on the vm while allocating pages.
1120 *
1121 * Arguments:
1122 *	oldhash  The hash you want to expand
1123 *	newhash  The hash structure for the new table
1124 *
1125 * Returns:
1126 *	Nothing
1127 *
1128 * Discussion:
1129 */
1130static int
1131hash_expand(struct uma_hash *oldhash, struct uma_hash *newhash)
1132{
1133	uma_hash_slab_t slab;
1134	u_int hval;
1135	u_int idx;
1136
1137	if (!newhash->uh_slab_hash)
1138		return (0);
1139
1140	if (oldhash->uh_hashsize >= newhash->uh_hashsize)
1141		return (0);
1142
1143	/*
1144	 * I need to investigate hash algorithms for resizing without a
1145	 * full rehash.
1146	 */
1147
1148	for (idx = 0; idx < oldhash->uh_hashsize; idx++)
1149		while (!LIST_EMPTY(&oldhash->uh_slab_hash[idx])) {
1150			slab = LIST_FIRST(&oldhash->uh_slab_hash[idx]);
1151			LIST_REMOVE(slab, uhs_hlink);
1152			hval = UMA_HASH(newhash, slab->uhs_data);
1153			LIST_INSERT_HEAD(&newhash->uh_slab_hash[hval],
1154			    slab, uhs_hlink);
1155		}
1156
1157	return (1);
1158}
1159
1160/*
1161 * Free the hash bucket to the appropriate backing store.
1162 *
1163 * Arguments:
1164 *	slab_hash  The hash bucket we're freeing
1165 *	hashsize   The number of entries in that hash bucket
1166 *
1167 * Returns:
1168 *	Nothing
1169 */
1170static void
1171hash_free(struct uma_hash *hash)
1172{
1173	if (hash->uh_slab_hash == NULL)
1174		return;
1175	if (hash->uh_hashsize == UMA_HASH_SIZE_INIT)
1176		zone_free_item(hashzone, hash->uh_slab_hash, NULL, SKIP_NONE);
1177	else
1178		free(hash->uh_slab_hash, M_UMAHASH);
1179}
1180
1181/*
1182 * Frees all outstanding items in a bucket
1183 *
1184 * Arguments:
1185 *	zone   The zone to free to, must be unlocked.
1186 *	bucket The free/alloc bucket with items.
1187 *
1188 * Returns:
1189 *	Nothing
1190 */
1191static void
1192bucket_drain(uma_zone_t zone, uma_bucket_t bucket)
1193{
1194	int i;
1195
1196	if (bucket->ub_cnt == 0)
1197		return;
1198
1199	if ((zone->uz_flags & UMA_ZONE_SMR) != 0 &&
1200	    bucket->ub_seq != SMR_SEQ_INVALID) {
1201		smr_wait(zone->uz_smr, bucket->ub_seq);
1202		bucket->ub_seq = SMR_SEQ_INVALID;
1203		for (i = 0; i < bucket->ub_cnt; i++)
1204			item_dtor(zone, bucket->ub_bucket[i],
1205			    zone->uz_size, NULL, SKIP_NONE);
1206	}
1207	if (zone->uz_fini)
1208		for (i = 0; i < bucket->ub_cnt; i++)
1209			zone->uz_fini(bucket->ub_bucket[i], zone->uz_size);
1210	zone->uz_release(zone->uz_arg, bucket->ub_bucket, bucket->ub_cnt);
1211	if (zone->uz_max_items > 0)
1212		zone_free_limit(zone, bucket->ub_cnt);
1213#ifdef INVARIANTS
1214	bzero(bucket->ub_bucket, sizeof(void *) * bucket->ub_cnt);
1215#endif
1216	bucket->ub_cnt = 0;
1217}
1218
1219/*
1220 * Drains the per cpu caches for a zone.
1221 *
1222 * NOTE: This may only be called while the zone is being torn down, and not
1223 * during normal operation.  This is necessary in order that we do not have
1224 * to migrate CPUs to drain the per-CPU caches.
1225 *
1226 * Arguments:
1227 *	zone     The zone to drain, must be unlocked.
1228 *
1229 * Returns:
1230 *	Nothing
1231 */
1232static void
1233cache_drain(uma_zone_t zone)
1234{
1235	uma_cache_t cache;
1236	uma_bucket_t bucket;
1237	smr_seq_t seq;
1238	int cpu;
1239
1240	/*
1241	 * XXX: It is safe to not lock the per-CPU caches, because we're
1242	 * tearing down the zone anyway.  I.e., there will be no further use
1243	 * of the caches at this point.
1244	 *
1245	 * XXX: It would good to be able to assert that the zone is being
1246	 * torn down to prevent improper use of cache_drain().
1247	 */
1248	seq = SMR_SEQ_INVALID;
1249	if ((zone->uz_flags & UMA_ZONE_SMR) != 0)
1250		seq = smr_advance(zone->uz_smr);
1251	CPU_FOREACH(cpu) {
1252		cache = &zone->uz_cpu[cpu];
1253		bucket = cache_bucket_unload_alloc(cache);
1254		if (bucket != NULL)
1255			bucket_free(zone, bucket, NULL);
1256		bucket = cache_bucket_unload_free(cache);
1257		if (bucket != NULL) {
1258			bucket->ub_seq = seq;
1259			bucket_free(zone, bucket, NULL);
1260		}
1261		bucket = cache_bucket_unload_cross(cache);
1262		if (bucket != NULL) {
1263			bucket->ub_seq = seq;
1264			bucket_free(zone, bucket, NULL);
1265		}
1266	}
1267	bucket_cache_reclaim(zone, true, UMA_ANYDOMAIN);
1268}
1269
1270static void
1271cache_shrink(uma_zone_t zone, void *unused)
1272{
1273
1274	if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
1275		return;
1276
1277	ZONE_LOCK(zone);
1278	zone->uz_bucket_size =
1279	    (zone->uz_bucket_size_min + zone->uz_bucket_size) / 2;
1280	ZONE_UNLOCK(zone);
1281}
1282
1283static void
1284cache_drain_safe_cpu(uma_zone_t zone, void *unused)
1285{
1286	uma_cache_t cache;
1287	uma_bucket_t b1, b2, b3;
1288	int domain;
1289
1290	if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
1291		return;
1292
1293	b1 = b2 = b3 = NULL;
1294	critical_enter();
1295	cache = &zone->uz_cpu[curcpu];
1296	domain = PCPU_GET(domain);
1297	b1 = cache_bucket_unload_alloc(cache);
1298
1299	/*
1300	 * Don't flush SMR zone buckets.  This leaves the zone without a
1301	 * bucket and forces every free to synchronize().
1302	 */
1303	if ((zone->uz_flags & UMA_ZONE_SMR) == 0) {
1304		b2 = cache_bucket_unload_free(cache);
1305		b3 = cache_bucket_unload_cross(cache);
1306	}
1307	critical_exit();
1308
1309	if (b1 != NULL)
1310		zone_free_bucket(zone, b1, NULL, domain, false);
1311	if (b2 != NULL)
1312		zone_free_bucket(zone, b2, NULL, domain, false);
1313	if (b3 != NULL) {
1314		/* Adjust the domain so it goes to zone_free_cross. */
1315		domain = (domain + 1) % vm_ndomains;
1316		zone_free_bucket(zone, b3, NULL, domain, false);
1317	}
1318}
1319
1320/*
1321 * Safely drain per-CPU caches of a zone(s) to alloc bucket.
1322 * This is an expensive call because it needs to bind to all CPUs
1323 * one by one and enter a critical section on each of them in order
1324 * to safely access their cache buckets.
1325 * Zone lock must not be held on call this function.
1326 */
1327static void
1328pcpu_cache_drain_safe(uma_zone_t zone)
1329{
1330	int cpu;
1331
1332	/*
1333	 * Polite bucket sizes shrinking was not enough, shrink aggressively.
1334	 */
1335	if (zone)
1336		cache_shrink(zone, NULL);
1337	else
1338		zone_foreach(cache_shrink, NULL);
1339
1340	CPU_FOREACH(cpu) {
1341		thread_lock(curthread);
1342		sched_bind(curthread, cpu);
1343		thread_unlock(curthread);
1344
1345		if (zone)
1346			cache_drain_safe_cpu(zone, NULL);
1347		else
1348			zone_foreach(cache_drain_safe_cpu, NULL);
1349	}
1350	thread_lock(curthread);
1351	sched_unbind(curthread);
1352	thread_unlock(curthread);
1353}
1354
1355/*
1356 * Reclaim cached buckets from a zone.  All buckets are reclaimed if the caller
1357 * requested a drain, otherwise the per-domain caches are trimmed to either
1358 * estimated working set size.
1359 */
1360static bool
1361bucket_cache_reclaim_domain(uma_zone_t zone, bool drain, bool trim, int domain)
1362{
1363	uma_zone_domain_t zdom;
1364	uma_bucket_t bucket;
1365	long target;
1366	bool done = false;
1367
1368	/*
1369	 * The cross bucket is partially filled and not part of
1370	 * the item count.  Reclaim it individually here.
1371	 */
1372	zdom = ZDOM_GET(zone, domain);
1373	if ((zone->uz_flags & UMA_ZONE_SMR) == 0 || drain) {
1374		ZONE_CROSS_LOCK(zone);
1375		bucket = zdom->uzd_cross;
1376		zdom->uzd_cross = NULL;
1377		ZONE_CROSS_UNLOCK(zone);
1378		if (bucket != NULL)
1379			bucket_free(zone, bucket, NULL);
1380	}
1381
1382	/*
1383	 * If we were asked to drain the zone, we are done only once
1384	 * this bucket cache is empty.  If trim, we reclaim items in
1385	 * excess of the zone's estimated working set size.  Multiple
1386	 * consecutive calls will shrink the WSS and so reclaim more.
1387	 * If neither drain nor trim, then voluntarily reclaim 1/4
1388	 * (to reduce first spike) of items not used for a long time.
1389	 */
1390	ZDOM_LOCK(zdom);
1391	zone_domain_update_wss(zdom);
1392	if (drain)
1393		target = 0;
1394	else if (trim)
1395		target = zdom->uzd_wss;
1396	else if (zdom->uzd_timin > 900 / UMA_TIMEOUT)
1397		target = zdom->uzd_nitems - zdom->uzd_limin / 4;
1398	else {
1399		ZDOM_UNLOCK(zdom);
1400		return (done);
1401	}
1402	while ((bucket = STAILQ_FIRST(&zdom->uzd_buckets)) != NULL &&
1403	    zdom->uzd_nitems >= target + bucket->ub_cnt) {
1404		bucket = zone_fetch_bucket(zone, zdom, true);
1405		if (bucket == NULL)
1406			break;
1407		bucket_free(zone, bucket, NULL);
1408		done = true;
1409		ZDOM_LOCK(zdom);
1410	}
1411	ZDOM_UNLOCK(zdom);
1412	return (done);
1413}
1414
1415static void
1416bucket_cache_reclaim(uma_zone_t zone, bool drain, int domain)
1417{
1418	int i;
1419
1420	/*
1421	 * Shrink the zone bucket size to ensure that the per-CPU caches
1422	 * don't grow too large.
1423	 */
1424	if (zone->uz_bucket_size > zone->uz_bucket_size_min)
1425		zone->uz_bucket_size--;
1426
1427	if (domain != UMA_ANYDOMAIN &&
1428	    (zone->uz_flags & UMA_ZONE_ROUNDROBIN) == 0) {
1429		bucket_cache_reclaim_domain(zone, drain, true, domain);
1430	} else {
1431		for (i = 0; i < vm_ndomains; i++)
1432			bucket_cache_reclaim_domain(zone, drain, true, i);
1433	}
1434}
1435
1436static void
1437keg_free_slab(uma_keg_t keg, uma_slab_t slab, int start)
1438{
1439	uint8_t *mem;
1440	int i;
1441	uint8_t flags;
1442
1443	CTR4(KTR_UMA, "keg_free_slab keg %s(%p) slab %p, returning %d bytes",
1444	    keg->uk_name, keg, slab, PAGE_SIZE * keg->uk_ppera);
1445
1446	mem = slab_data(slab, keg);
1447	flags = slab->us_flags;
1448	i = start;
1449	if (keg->uk_fini != NULL) {
1450		for (i--; i > -1; i--)
1451#ifdef INVARIANTS
1452		/*
1453		 * trash_fini implies that dtor was trash_dtor. trash_fini
1454		 * would check that memory hasn't been modified since free,
1455		 * which executed trash_dtor.
1456		 * That's why we need to run uma_dbg_kskip() check here,
1457		 * albeit we don't make skip check for other init/fini
1458		 * invocations.
1459		 */
1460		if (!uma_dbg_kskip(keg, slab_item(slab, keg, i)) ||
1461		    keg->uk_fini != trash_fini)
1462#endif
1463			keg->uk_fini(slab_item(slab, keg, i), keg->uk_size);
1464	}
1465	if (keg->uk_flags & UMA_ZFLAG_OFFPAGE)
1466		zone_free_item(slabzone(keg->uk_ipers), slab_tohashslab(slab),
1467		    NULL, SKIP_NONE);
1468	keg->uk_freef(mem, PAGE_SIZE * keg->uk_ppera, flags);
1469	uma_total_dec(PAGE_SIZE * keg->uk_ppera);
1470}
1471
1472static void
1473keg_drain_domain(uma_keg_t keg, int domain)
1474{
1475	struct slabhead freeslabs;
1476	uma_domain_t dom;
1477	uma_slab_t slab, tmp;
1478	uint32_t i, stofree, stokeep, partial;
1479
1480	dom = &keg->uk_domain[domain];
1481	LIST_INIT(&freeslabs);
1482
1483	CTR4(KTR_UMA, "keg_drain %s(%p) domain %d free items: %u",
1484	    keg->uk_name, keg, domain, dom->ud_free_items);
1485
1486	KEG_LOCK(keg, domain);
1487
1488	/*
1489	 * Are the free items in partially allocated slabs sufficient to meet
1490	 * the reserve? If not, compute the number of fully free slabs that must
1491	 * be kept.
1492	 */
1493	partial = dom->ud_free_items - dom->ud_free_slabs * keg->uk_ipers;
1494	if (partial < keg->uk_reserve) {
1495		stokeep = min(dom->ud_free_slabs,
1496		    howmany(keg->uk_reserve - partial, keg->uk_ipers));
1497	} else {
1498		stokeep = 0;
1499	}
1500	stofree = dom->ud_free_slabs - stokeep;
1501
1502	/*
1503	 * Partition the free slabs into two sets: those that must be kept in
1504	 * order to maintain the reserve, and those that may be released back to
1505	 * the system.  Since one set may be much larger than the other,
1506	 * populate the smaller of the two sets and swap them if necessary.
1507	 */
1508	for (i = min(stofree, stokeep); i > 0; i--) {
1509		slab = LIST_FIRST(&dom->ud_free_slab);
1510		LIST_REMOVE(slab, us_link);
1511		LIST_INSERT_HEAD(&freeslabs, slab, us_link);
1512	}
1513	if (stofree > stokeep)
1514		LIST_SWAP(&freeslabs, &dom->ud_free_slab, uma_slab, us_link);
1515
1516	if ((keg->uk_flags & UMA_ZFLAG_HASH) != 0) {
1517		LIST_FOREACH(slab, &freeslabs, us_link)
1518			UMA_HASH_REMOVE(&keg->uk_hash, slab);
1519	}
1520	dom->ud_free_items -= stofree * keg->uk_ipers;
1521	dom->ud_free_slabs -= stofree;
1522	dom->ud_pages -= stofree * keg->uk_ppera;
1523	KEG_UNLOCK(keg, domain);
1524
1525	LIST_FOREACH_SAFE(slab, &freeslabs, us_link, tmp)
1526		keg_free_slab(keg, slab, keg->uk_ipers);
1527}
1528
1529/*
1530 * Frees pages from a keg back to the system.  This is done on demand from
1531 * the pageout daemon.
1532 *
1533 * Returns nothing.
1534 */
1535static void
1536keg_drain(uma_keg_t keg, int domain)
1537{
1538	int i;
1539
1540	if ((keg->uk_flags & UMA_ZONE_NOFREE) != 0)
1541		return;
1542	if (domain != UMA_ANYDOMAIN) {
1543		keg_drain_domain(keg, domain);
1544	} else {
1545		for (i = 0; i < vm_ndomains; i++)
1546			keg_drain_domain(keg, i);
1547	}
1548}
1549
1550static void
1551zone_reclaim(uma_zone_t zone, int domain, int waitok, bool drain)
1552{
1553	/*
1554	 * Count active reclaim operations in order to interlock with
1555	 * zone_dtor(), which removes the zone from global lists before
1556	 * attempting to reclaim items itself.
1557	 *
1558	 * The zone may be destroyed while sleeping, so only zone_dtor() should
1559	 * specify M_WAITOK.
1560	 */
1561	ZONE_LOCK(zone);
1562	if (waitok == M_WAITOK) {
1563		while (zone->uz_reclaimers > 0)
1564			msleep(zone, ZONE_LOCKPTR(zone), PVM, "zonedrain", 1);
1565	}
1566	zone->uz_reclaimers++;
1567	ZONE_UNLOCK(zone);
1568	bucket_cache_reclaim(zone, drain, domain);
1569
1570	if ((zone->uz_flags & UMA_ZFLAG_CACHE) == 0)
1571		keg_drain(zone->uz_keg, domain);
1572	ZONE_LOCK(zone);
1573	zone->uz_reclaimers--;
1574	if (zone->uz_reclaimers == 0)
1575		wakeup(zone);
1576	ZONE_UNLOCK(zone);
1577}
1578
1579static void
1580zone_drain(uma_zone_t zone, void *arg)
1581{
1582	int domain;
1583
1584	domain = (int)(uintptr_t)arg;
1585	zone_reclaim(zone, domain, M_NOWAIT, true);
1586}
1587
1588static void
1589zone_trim(uma_zone_t zone, void *arg)
1590{
1591	int domain;
1592
1593	domain = (int)(uintptr_t)arg;
1594	zone_reclaim(zone, domain, M_NOWAIT, false);
1595}
1596
1597/*
1598 * Allocate a new slab for a keg and inserts it into the partial slab list.
1599 * The keg should be unlocked on entry.  If the allocation succeeds it will
1600 * be locked on return.
1601 *
1602 * Arguments:
1603 *	flags   Wait flags for the item initialization routine
1604 *	aflags  Wait flags for the slab allocation
1605 *
1606 * Returns:
1607 *	The slab that was allocated or NULL if there is no memory and the
1608 *	caller specified M_NOWAIT.
1609 */
1610static uma_slab_t
1611keg_alloc_slab(uma_keg_t keg, uma_zone_t zone, int domain, int flags,
1612    int aflags)
1613{
1614	uma_domain_t dom;
1615	uma_alloc allocf;
1616	uma_slab_t slab;
1617	unsigned long size;
1618	uint8_t *mem;
1619	uint8_t sflags;
1620	int i;
1621
1622	KASSERT(domain >= 0 && domain < vm_ndomains,
1623	    ("keg_alloc_slab: domain %d out of range", domain));
1624
1625	allocf = keg->uk_allocf;
1626	slab = NULL;
1627	mem = NULL;
1628	if (keg->uk_flags & UMA_ZFLAG_OFFPAGE) {
1629		uma_hash_slab_t hslab;
1630		hslab = zone_alloc_item(slabzone(keg->uk_ipers), NULL,
1631		    domain, aflags);
1632		if (hslab == NULL)
1633			goto fail;
1634		slab = &hslab->uhs_slab;
1635	}
1636
1637	/*
1638	 * This reproduces the old vm_zone behavior of zero filling pages the
1639	 * first time they are added to a zone.
1640	 *
1641	 * Malloced items are zeroed in uma_zalloc.
1642	 */
1643
1644	if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
1645		aflags |= M_ZERO;
1646	else
1647		aflags &= ~M_ZERO;
1648
1649	if (keg->uk_flags & UMA_ZONE_NODUMP)
1650		aflags |= M_NODUMP;
1651
1652	/* zone is passed for legacy reasons. */
1653	size = keg->uk_ppera * PAGE_SIZE;
1654	mem = allocf(zone, size, domain, &sflags, aflags);
1655	if (mem == NULL) {
1656		if (keg->uk_flags & UMA_ZFLAG_OFFPAGE)
1657			zone_free_item(slabzone(keg->uk_ipers),
1658			    slab_tohashslab(slab), NULL, SKIP_NONE);
1659		goto fail;
1660	}
1661	uma_total_inc(size);
1662
1663	/* For HASH zones all pages go to the same uma_domain. */
1664	if ((keg->uk_flags & UMA_ZFLAG_HASH) != 0)
1665		domain = 0;
1666
1667	/* Point the slab into the allocated memory */
1668	if (!(keg->uk_flags & UMA_ZFLAG_OFFPAGE))
1669		slab = (uma_slab_t )(mem + keg->uk_pgoff);
1670	else
1671		slab_tohashslab(slab)->uhs_data = mem;
1672
1673	if (keg->uk_flags & UMA_ZFLAG_VTOSLAB)
1674		for (i = 0; i < keg->uk_ppera; i++)
1675			vsetzoneslab((vm_offset_t)mem + (i * PAGE_SIZE),
1676			    zone, slab);
1677
1678	slab->us_freecount = keg->uk_ipers;
1679	slab->us_flags = sflags;
1680	slab->us_domain = domain;
1681
1682	BIT_FILL(keg->uk_ipers, &slab->us_free);
1683#ifdef INVARIANTS
1684	BIT_ZERO(keg->uk_ipers, slab_dbg_bits(slab, keg));
1685#endif
1686
1687	if (keg->uk_init != NULL) {
1688		for (i = 0; i < keg->uk_ipers; i++)
1689			if (keg->uk_init(slab_item(slab, keg, i),
1690			    keg->uk_size, flags) != 0)
1691				break;
1692		if (i != keg->uk_ipers) {
1693			keg_free_slab(keg, slab, i);
1694			goto fail;
1695		}
1696	}
1697	KEG_LOCK(keg, domain);
1698
1699	CTR3(KTR_UMA, "keg_alloc_slab: allocated slab %p for %s(%p)",
1700	    slab, keg->uk_name, keg);
1701
1702	if (keg->uk_flags & UMA_ZFLAG_HASH)
1703		UMA_HASH_INSERT(&keg->uk_hash, slab, mem);
1704
1705	/*
1706	 * If we got a slab here it's safe to mark it partially used
1707	 * and return.  We assume that the caller is going to remove
1708	 * at least one item.
1709	 */
1710	dom = &keg->uk_domain[domain];
1711	LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
1712	dom->ud_pages += keg->uk_ppera;
1713	dom->ud_free_items += keg->uk_ipers;
1714
1715	return (slab);
1716
1717fail:
1718	return (NULL);
1719}
1720
1721/*
1722 * This function is intended to be used early on in place of page_alloc().  It
1723 * performs contiguous physical memory allocations and uses a bump allocator for
1724 * KVA, so is usable before the kernel map is initialized.
1725 */
1726static void *
1727startup_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
1728    int wait)
1729{
1730	vm_paddr_t pa;
1731	vm_page_t m;
1732	void *mem;
1733	int pages;
1734	int i;
1735
1736	pages = howmany(bytes, PAGE_SIZE);
1737	KASSERT(pages > 0, ("%s can't reserve 0 pages", __func__));
1738
1739	*pflag = UMA_SLAB_BOOT;
1740	m = vm_page_alloc_contig_domain(NULL, 0, domain,
1741	    malloc2vm_flags(wait) | VM_ALLOC_NOOBJ | VM_ALLOC_WIRED, pages,
1742	    (vm_paddr_t)0, ~(vm_paddr_t)0, 1, 0, VM_MEMATTR_DEFAULT);
1743	if (m == NULL)
1744		return (NULL);
1745
1746	pa = VM_PAGE_TO_PHYS(m);
1747	for (i = 0; i < pages; i++, pa += PAGE_SIZE) {
1748#if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) || \
1749    defined(__riscv) || defined(__powerpc64__)
1750		if ((wait & M_NODUMP) == 0)
1751			dump_add_page(pa);
1752#endif
1753	}
1754	/* Allocate KVA and indirectly advance bootmem. */
1755	mem = (void *)pmap_map(&bootmem, m->phys_addr,
1756	    m->phys_addr + (pages * PAGE_SIZE), VM_PROT_READ | VM_PROT_WRITE);
1757        if ((wait & M_ZERO) != 0)
1758                bzero(mem, pages * PAGE_SIZE);
1759
1760        return (mem);
1761}
1762
1763static void
1764startup_free(void *mem, vm_size_t bytes)
1765{
1766	vm_offset_t va;
1767	vm_page_t m;
1768
1769	va = (vm_offset_t)mem;
1770	m = PHYS_TO_VM_PAGE(pmap_kextract(va));
1771
1772	/*
1773	 * startup_alloc() returns direct-mapped slabs on some platforms.  Avoid
1774	 * unmapping ranges of the direct map.
1775	 */
1776	if (va >= bootstart && va + bytes <= bootmem)
1777		pmap_remove(kernel_pmap, va, va + bytes);
1778	for (; bytes != 0; bytes -= PAGE_SIZE, m++) {
1779#if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) || \
1780    defined(__riscv) || defined(__powerpc64__)
1781		dump_drop_page(VM_PAGE_TO_PHYS(m));
1782#endif
1783		vm_page_unwire_noq(m);
1784		vm_page_free(m);
1785	}
1786}
1787
1788/*
1789 * Allocates a number of pages from the system
1790 *
1791 * Arguments:
1792 *	bytes  The number of bytes requested
1793 *	wait  Shall we wait?
1794 *
1795 * Returns:
1796 *	A pointer to the alloced memory or possibly
1797 *	NULL if M_NOWAIT is set.
1798 */
1799static void *
1800page_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
1801    int wait)
1802{
1803	void *p;	/* Returned page */
1804
1805	*pflag = UMA_SLAB_KERNEL;
1806	p = (void *)kmem_malloc_domainset(DOMAINSET_FIXED(domain), bytes, wait);
1807
1808	return (p);
1809}
1810
1811static void *
1812pcpu_page_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
1813    int wait)
1814{
1815	struct pglist alloctail;
1816	vm_offset_t addr, zkva;
1817	int cpu, flags;
1818	vm_page_t p, p_next;
1819#ifdef NUMA
1820	struct pcpu *pc;
1821#endif
1822
1823	MPASS(bytes == (mp_maxid + 1) * PAGE_SIZE);
1824
1825	TAILQ_INIT(&alloctail);
1826	flags = VM_ALLOC_SYSTEM | VM_ALLOC_WIRED | VM_ALLOC_NOOBJ |
1827	    malloc2vm_flags(wait);
1828	*pflag = UMA_SLAB_KERNEL;
1829	for (cpu = 0; cpu <= mp_maxid; cpu++) {
1830		if (CPU_ABSENT(cpu)) {
1831			p = vm_page_alloc(NULL, 0, flags);
1832		} else {
1833#ifndef NUMA
1834			p = vm_page_alloc(NULL, 0, flags);
1835#else
1836			pc = pcpu_find(cpu);
1837			if (__predict_false(VM_DOMAIN_EMPTY(pc->pc_domain)))
1838				p = NULL;
1839			else
1840				p = vm_page_alloc_domain(NULL, 0,
1841				    pc->pc_domain, flags);
1842			if (__predict_false(p == NULL))
1843				p = vm_page_alloc(NULL, 0, flags);
1844#endif
1845		}
1846		if (__predict_false(p == NULL))
1847			goto fail;
1848		TAILQ_INSERT_TAIL(&alloctail, p, listq);
1849	}
1850	if ((addr = kva_alloc(bytes)) == 0)
1851		goto fail;
1852	zkva = addr;
1853	TAILQ_FOREACH(p, &alloctail, listq) {
1854		pmap_qenter(zkva, &p, 1);
1855		zkva += PAGE_SIZE;
1856	}
1857	return ((void*)addr);
1858fail:
1859	TAILQ_FOREACH_SAFE(p, &alloctail, listq, p_next) {
1860		vm_page_unwire_noq(p);
1861		vm_page_free(p);
1862	}
1863	return (NULL);
1864}
1865
1866/*
1867 * Allocates a number of pages from within an object
1868 *
1869 * Arguments:
1870 *	bytes  The number of bytes requested
1871 *	wait   Shall we wait?
1872 *
1873 * Returns:
1874 *	A pointer to the alloced memory or possibly
1875 *	NULL if M_NOWAIT is set.
1876 */
1877static void *
1878noobj_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *flags,
1879    int wait)
1880{
1881	TAILQ_HEAD(, vm_page) alloctail;
1882	u_long npages;
1883	vm_offset_t retkva, zkva;
1884	vm_page_t p, p_next;
1885	uma_keg_t keg;
1886
1887	TAILQ_INIT(&alloctail);
1888	keg = zone->uz_keg;
1889
1890	npages = howmany(bytes, PAGE_SIZE);
1891	while (npages > 0) {
1892		p = vm_page_alloc_domain(NULL, 0, domain, VM_ALLOC_INTERRUPT |
1893		    VM_ALLOC_WIRED | VM_ALLOC_NOOBJ |
1894		    ((wait & M_WAITOK) != 0 ? VM_ALLOC_WAITOK :
1895		    VM_ALLOC_NOWAIT));
1896		if (p != NULL) {
1897			/*
1898			 * Since the page does not belong to an object, its
1899			 * listq is unused.
1900			 */
1901			TAILQ_INSERT_TAIL(&alloctail, p, listq);
1902			npages--;
1903			continue;
1904		}
1905		/*
1906		 * Page allocation failed, free intermediate pages and
1907		 * exit.
1908		 */
1909		TAILQ_FOREACH_SAFE(p, &alloctail, listq, p_next) {
1910			vm_page_unwire_noq(p);
1911			vm_page_free(p);
1912		}
1913		return (NULL);
1914	}
1915	*flags = UMA_SLAB_PRIV;
1916	zkva = keg->uk_kva +
1917	    atomic_fetchadd_long(&keg->uk_offset, round_page(bytes));
1918	retkva = zkva;
1919	TAILQ_FOREACH(p, &alloctail, listq) {
1920		pmap_qenter(zkva, &p, 1);
1921		zkva += PAGE_SIZE;
1922	}
1923
1924	return ((void *)retkva);
1925}
1926
1927/*
1928 * Allocate physically contiguous pages.
1929 */
1930static void *
1931contig_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
1932    int wait)
1933{
1934
1935	*pflag = UMA_SLAB_KERNEL;
1936	return ((void *)kmem_alloc_contig_domainset(DOMAINSET_FIXED(domain),
1937	    bytes, wait, 0, ~(vm_paddr_t)0, 1, 0, VM_MEMATTR_DEFAULT));
1938}
1939
1940/*
1941 * Frees a number of pages to the system
1942 *
1943 * Arguments:
1944 *	mem   A pointer to the memory to be freed
1945 *	size  The size of the memory being freed
1946 *	flags The original p->us_flags field
1947 *
1948 * Returns:
1949 *	Nothing
1950 */
1951static void
1952page_free(void *mem, vm_size_t size, uint8_t flags)
1953{
1954
1955	if ((flags & UMA_SLAB_BOOT) != 0) {
1956		startup_free(mem, size);
1957		return;
1958	}
1959
1960	KASSERT((flags & UMA_SLAB_KERNEL) != 0,
1961	    ("UMA: page_free used with invalid flags %x", flags));
1962
1963	kmem_free((vm_offset_t)mem, size);
1964}
1965
1966/*
1967 * Frees pcpu zone allocations
1968 *
1969 * Arguments:
1970 *	mem   A pointer to the memory to be freed
1971 *	size  The size of the memory being freed
1972 *	flags The original p->us_flags field
1973 *
1974 * Returns:
1975 *	Nothing
1976 */
1977static void
1978pcpu_page_free(void *mem, vm_size_t size, uint8_t flags)
1979{
1980	vm_offset_t sva, curva;
1981	vm_paddr_t paddr;
1982	vm_page_t m;
1983
1984	MPASS(size == (mp_maxid+1)*PAGE_SIZE);
1985
1986	if ((flags & UMA_SLAB_BOOT) != 0) {
1987		startup_free(mem, size);
1988		return;
1989	}
1990
1991	sva = (vm_offset_t)mem;
1992	for (curva = sva; curva < sva + size; curva += PAGE_SIZE) {
1993		paddr = pmap_kextract(curva);
1994		m = PHYS_TO_VM_PAGE(paddr);
1995		vm_page_unwire_noq(m);
1996		vm_page_free(m);
1997	}
1998	pmap_qremove(sva, size >> PAGE_SHIFT);
1999	kva_free(sva, size);
2000}
2001
2002/*
2003 * Zero fill initializer
2004 *
2005 * Arguments/Returns follow uma_init specifications
2006 */
2007static int
2008zero_init(void *mem, int size, int flags)
2009{
2010	bzero(mem, size);
2011	return (0);
2012}
2013
2014#ifdef INVARIANTS
2015static struct noslabbits *
2016slab_dbg_bits(uma_slab_t slab, uma_keg_t keg)
2017{
2018
2019	return ((void *)((char *)&slab->us_free + BITSET_SIZE(keg->uk_ipers)));
2020}
2021#endif
2022
2023/*
2024 * Actual size of embedded struct slab (!OFFPAGE).
2025 */
2026static size_t
2027slab_sizeof(int nitems)
2028{
2029	size_t s;
2030
2031	s = sizeof(struct uma_slab) + BITSET_SIZE(nitems) * SLAB_BITSETS;
2032	return (roundup(s, UMA_ALIGN_PTR + 1));
2033}
2034
2035#define	UMA_FIXPT_SHIFT	31
2036#define	UMA_FRAC_FIXPT(n, d)						\
2037	((uint32_t)(((uint64_t)(n) << UMA_FIXPT_SHIFT) / (d)))
2038#define	UMA_FIXPT_PCT(f)						\
2039	((u_int)(((uint64_t)100 * (f)) >> UMA_FIXPT_SHIFT))
2040#define	UMA_PCT_FIXPT(pct)	UMA_FRAC_FIXPT((pct), 100)
2041#define	UMA_MIN_EFF	UMA_PCT_FIXPT(100 - UMA_MAX_WASTE)
2042
2043/*
2044 * Compute the number of items that will fit in a slab.  If hdr is true, the
2045 * item count may be limited to provide space in the slab for an inline slab
2046 * header.  Otherwise, all slab space will be provided for item storage.
2047 */
2048static u_int
2049slab_ipers_hdr(u_int size, u_int rsize, u_int slabsize, bool hdr)
2050{
2051	u_int ipers;
2052	u_int padpi;
2053
2054	/* The padding between items is not needed after the last item. */
2055	padpi = rsize - size;
2056
2057	if (hdr) {
2058		/*
2059		 * Start with the maximum item count and remove items until
2060		 * the slab header first alongside the allocatable memory.
2061		 */
2062		for (ipers = MIN(SLAB_MAX_SETSIZE,
2063		    (slabsize + padpi - slab_sizeof(1)) / rsize);
2064		    ipers > 0 &&
2065		    ipers * rsize - padpi + slab_sizeof(ipers) > slabsize;
2066		    ipers--)
2067			continue;
2068	} else {
2069		ipers = MIN((slabsize + padpi) / rsize, SLAB_MAX_SETSIZE);
2070	}
2071
2072	return (ipers);
2073}
2074
2075struct keg_layout_result {
2076	u_int format;
2077	u_int slabsize;
2078	u_int ipers;
2079	u_int eff;
2080};
2081
2082static void
2083keg_layout_one(uma_keg_t keg, u_int rsize, u_int slabsize, u_int fmt,
2084    struct keg_layout_result *kl)
2085{
2086	u_int total;
2087
2088	kl->format = fmt;
2089	kl->slabsize = slabsize;
2090
2091	/* Handle INTERNAL as inline with an extra page. */
2092	if ((fmt & UMA_ZFLAG_INTERNAL) != 0) {
2093		kl->format &= ~UMA_ZFLAG_INTERNAL;
2094		kl->slabsize += PAGE_SIZE;
2095	}
2096
2097	kl->ipers = slab_ipers_hdr(keg->uk_size, rsize, kl->slabsize,
2098	    (fmt & UMA_ZFLAG_OFFPAGE) == 0);
2099
2100	/* Account for memory used by an offpage slab header. */
2101	total = kl->slabsize;
2102	if ((fmt & UMA_ZFLAG_OFFPAGE) != 0)
2103		total += slabzone(kl->ipers)->uz_keg->uk_rsize;
2104
2105	kl->eff = UMA_FRAC_FIXPT(kl->ipers * rsize, total);
2106}
2107
2108/*
2109 * Determine the format of a uma keg.  This determines where the slab header
2110 * will be placed (inline or offpage) and calculates ipers, rsize, and ppera.
2111 *
2112 * Arguments
2113 *	keg  The zone we should initialize
2114 *
2115 * Returns
2116 *	Nothing
2117 */
2118static void
2119keg_layout(uma_keg_t keg)
2120{
2121	struct keg_layout_result kl = {}, kl_tmp;
2122	u_int fmts[2];
2123	u_int alignsize;
2124	u_int nfmt;
2125	u_int pages;
2126	u_int rsize;
2127	u_int slabsize;
2128	u_int i, j;
2129
2130	KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0 ||
2131	    (keg->uk_size <= UMA_PCPU_ALLOC_SIZE &&
2132	     (keg->uk_flags & UMA_ZONE_CACHESPREAD) == 0),
2133	    ("%s: cannot configure for PCPU: keg=%s, size=%u, flags=0x%b",
2134	     __func__, keg->uk_name, keg->uk_size, keg->uk_flags,
2135	     PRINT_UMA_ZFLAGS));
2136	KASSERT((keg->uk_flags & (UMA_ZFLAG_INTERNAL | UMA_ZONE_VM)) == 0 ||
2137	    (keg->uk_flags & (UMA_ZONE_NOTOUCH | UMA_ZONE_PCPU)) == 0,
2138	    ("%s: incompatible flags 0x%b", __func__, keg->uk_flags,
2139	     PRINT_UMA_ZFLAGS));
2140
2141	alignsize = keg->uk_align + 1;
2142
2143	/*
2144	 * Calculate the size of each allocation (rsize) according to
2145	 * alignment.  If the requested size is smaller than we have
2146	 * allocation bits for we round it up.
2147	 */
2148	rsize = MAX(keg->uk_size, UMA_SMALLEST_UNIT);
2149	rsize = roundup2(rsize, alignsize);
2150
2151	if ((keg->uk_flags & UMA_ZONE_CACHESPREAD) != 0) {
2152		/*
2153		 * We want one item to start on every align boundary in a page.
2154		 * To do this we will span pages.  We will also extend the item
2155		 * by the size of align if it is an even multiple of align.
2156		 * Otherwise, it would fall on the same boundary every time.
2157		 */
2158		if ((rsize & alignsize) == 0)
2159			rsize += alignsize;
2160		slabsize = rsize * (PAGE_SIZE / alignsize);
2161		slabsize = MIN(slabsize, rsize * SLAB_MAX_SETSIZE);
2162		slabsize = MIN(slabsize, UMA_CACHESPREAD_MAX_SIZE);
2163		slabsize = round_page(slabsize);
2164	} else {
2165		/*
2166		 * Start with a slab size of as many pages as it takes to
2167		 * represent a single item.  We will try to fit as many
2168		 * additional items into the slab as possible.
2169		 */
2170		slabsize = round_page(keg->uk_size);
2171	}
2172
2173	/* Build a list of all of the available formats for this keg. */
2174	nfmt = 0;
2175
2176	/* Evaluate an inline slab layout. */
2177	if ((keg->uk_flags & (UMA_ZONE_NOTOUCH | UMA_ZONE_PCPU)) == 0)
2178		fmts[nfmt++] = 0;
2179
2180	/* TODO: vm_page-embedded slab. */
2181
2182	/*
2183	 * We can't do OFFPAGE if we're internal or if we've been
2184	 * asked to not go to the VM for buckets.  If we do this we
2185	 * may end up going to the VM for slabs which we do not want
2186	 * to do if we're UMA_ZONE_VM, which clearly forbids it.
2187	 * In those cases, evaluate a pseudo-format called INTERNAL
2188	 * which has an inline slab header and one extra page to
2189	 * guarantee that it fits.
2190	 *
2191	 * Otherwise, see if using an OFFPAGE slab will improve our
2192	 * efficiency.
2193	 */
2194	if ((keg->uk_flags & (UMA_ZFLAG_INTERNAL | UMA_ZONE_VM)) != 0)
2195		fmts[nfmt++] = UMA_ZFLAG_INTERNAL;
2196	else
2197		fmts[nfmt++] = UMA_ZFLAG_OFFPAGE;
2198
2199	/*
2200	 * Choose a slab size and format which satisfy the minimum efficiency.
2201	 * Prefer the smallest slab size that meets the constraints.
2202	 *
2203	 * Start with a minimum slab size, to accommodate CACHESPREAD.  Then,
2204	 * for small items (up to PAGE_SIZE), the iteration increment is one
2205	 * page; and for large items, the increment is one item.
2206	 */
2207	i = (slabsize + rsize - keg->uk_size) / MAX(PAGE_SIZE, rsize);
2208	KASSERT(i >= 1, ("keg %s(%p) flags=0x%b slabsize=%u, rsize=%u, i=%u",
2209	    keg->uk_name, keg, keg->uk_flags, PRINT_UMA_ZFLAGS, slabsize,
2210	    rsize, i));
2211	for ( ; ; i++) {
2212		slabsize = (rsize <= PAGE_SIZE) ? ptoa(i) :
2213		    round_page(rsize * (i - 1) + keg->uk_size);
2214
2215		for (j = 0; j < nfmt; j++) {
2216			/* Only if we have no viable format yet. */
2217			if ((fmts[j] & UMA_ZFLAG_INTERNAL) != 0 &&
2218			    kl.ipers > 0)
2219				continue;
2220
2221			keg_layout_one(keg, rsize, slabsize, fmts[j], &kl_tmp);
2222			if (kl_tmp.eff <= kl.eff)
2223				continue;
2224
2225			kl = kl_tmp;
2226
2227			CTR6(KTR_UMA, "keg %s layout: format %#x "
2228			    "(ipers %u * rsize %u) / slabsize %#x = %u%% eff",
2229			    keg->uk_name, kl.format, kl.ipers, rsize,
2230			    kl.slabsize, UMA_FIXPT_PCT(kl.eff));
2231
2232			/* Stop when we reach the minimum efficiency. */
2233			if (kl.eff >= UMA_MIN_EFF)
2234				break;
2235		}
2236
2237		if (kl.eff >= UMA_MIN_EFF || !multipage_slabs ||
2238		    slabsize >= SLAB_MAX_SETSIZE * rsize ||
2239		    (keg->uk_flags & (UMA_ZONE_PCPU | UMA_ZONE_CONTIG)) != 0)
2240			break;
2241	}
2242
2243	pages = atop(kl.slabsize);
2244	if ((keg->uk_flags & UMA_ZONE_PCPU) != 0)
2245		pages *= mp_maxid + 1;
2246
2247	keg->uk_rsize = rsize;
2248	keg->uk_ipers = kl.ipers;
2249	keg->uk_ppera = pages;
2250	keg->uk_flags |= kl.format;
2251
2252	/*
2253	 * How do we find the slab header if it is offpage or if not all item
2254	 * start addresses are in the same page?  We could solve the latter
2255	 * case with vaddr alignment, but we don't.
2256	 */
2257	if ((keg->uk_flags & UMA_ZFLAG_OFFPAGE) != 0 ||
2258	    (keg->uk_ipers - 1) * rsize >= PAGE_SIZE) {
2259		if ((keg->uk_flags & UMA_ZONE_NOTPAGE) != 0)
2260			keg->uk_flags |= UMA_ZFLAG_HASH;
2261		else
2262			keg->uk_flags |= UMA_ZFLAG_VTOSLAB;
2263	}
2264
2265	CTR6(KTR_UMA, "%s: keg=%s, flags=%#x, rsize=%u, ipers=%u, ppera=%u",
2266	    __func__, keg->uk_name, keg->uk_flags, rsize, keg->uk_ipers,
2267	    pages);
2268	KASSERT(keg->uk_ipers > 0 && keg->uk_ipers <= SLAB_MAX_SETSIZE,
2269	    ("%s: keg=%s, flags=0x%b, rsize=%u, ipers=%u, ppera=%u", __func__,
2270	     keg->uk_name, keg->uk_flags, PRINT_UMA_ZFLAGS, rsize,
2271	     keg->uk_ipers, pages));
2272}
2273
2274/*
2275 * Keg header ctor.  This initializes all fields, locks, etc.  And inserts
2276 * the keg onto the global keg list.
2277 *
2278 * Arguments/Returns follow uma_ctor specifications
2279 *	udata  Actually uma_kctor_args
2280 */
2281static int
2282keg_ctor(void *mem, int size, void *udata, int flags)
2283{
2284	struct uma_kctor_args *arg = udata;
2285	uma_keg_t keg = mem;
2286	uma_zone_t zone;
2287	int i;
2288
2289	bzero(keg, size);
2290	keg->uk_size = arg->size;
2291	keg->uk_init = arg->uminit;
2292	keg->uk_fini = arg->fini;
2293	keg->uk_align = arg->align;
2294	keg->uk_reserve = 0;
2295	keg->uk_flags = arg->flags;
2296
2297	/*
2298	 * We use a global round-robin policy by default.  Zones with
2299	 * UMA_ZONE_FIRSTTOUCH set will use first-touch instead, in which
2300	 * case the iterator is never run.
2301	 */
2302	keg->uk_dr.dr_policy = DOMAINSET_RR();
2303	keg->uk_dr.dr_iter = 0;
2304
2305	/*
2306	 * The primary zone is passed to us at keg-creation time.
2307	 */
2308	zone = arg->zone;
2309	keg->uk_name = zone->uz_name;
2310
2311	if (arg->flags & UMA_ZONE_ZINIT)
2312		keg->uk_init = zero_init;
2313
2314	if (arg->flags & UMA_ZONE_MALLOC)
2315		keg->uk_flags |= UMA_ZFLAG_VTOSLAB;
2316
2317#ifndef SMP
2318	keg->uk_flags &= ~UMA_ZONE_PCPU;
2319#endif
2320
2321	keg_layout(keg);
2322
2323	/*
2324	 * Use a first-touch NUMA policy for kegs that pmap_extract() will
2325	 * work on.  Use round-robin for everything else.
2326	 *
2327	 * Zones may override the default by specifying either.
2328	 */
2329#ifdef NUMA
2330	if ((keg->uk_flags &
2331	    (UMA_ZONE_ROUNDROBIN | UMA_ZFLAG_CACHE | UMA_ZONE_NOTPAGE)) == 0)
2332		keg->uk_flags |= UMA_ZONE_FIRSTTOUCH;
2333	else if ((keg->uk_flags & UMA_ZONE_FIRSTTOUCH) == 0)
2334		keg->uk_flags |= UMA_ZONE_ROUNDROBIN;
2335#endif
2336
2337	/*
2338	 * If we haven't booted yet we need allocations to go through the
2339	 * startup cache until the vm is ready.
2340	 */
2341#ifdef UMA_MD_SMALL_ALLOC
2342	if (keg->uk_ppera == 1)
2343		keg->uk_allocf = uma_small_alloc;
2344	else
2345#endif
2346	if (booted < BOOT_KVA)
2347		keg->uk_allocf = startup_alloc;
2348	else if (keg->uk_flags & UMA_ZONE_PCPU)
2349		keg->uk_allocf = pcpu_page_alloc;
2350	else if ((keg->uk_flags & UMA_ZONE_CONTIG) != 0 && keg->uk_ppera > 1)
2351		keg->uk_allocf = contig_alloc;
2352	else
2353		keg->uk_allocf = page_alloc;
2354#ifdef UMA_MD_SMALL_ALLOC
2355	if (keg->uk_ppera == 1)
2356		keg->uk_freef = uma_small_free;
2357	else
2358#endif
2359	if (keg->uk_flags & UMA_ZONE_PCPU)
2360		keg->uk_freef = pcpu_page_free;
2361	else
2362		keg->uk_freef = page_free;
2363
2364	/*
2365	 * Initialize keg's locks.
2366	 */
2367	for (i = 0; i < vm_ndomains; i++)
2368		KEG_LOCK_INIT(keg, i, (arg->flags & UMA_ZONE_MTXCLASS));
2369
2370	/*
2371	 * If we're putting the slab header in the actual page we need to
2372	 * figure out where in each page it goes.  See slab_sizeof
2373	 * definition.
2374	 */
2375	if (!(keg->uk_flags & UMA_ZFLAG_OFFPAGE)) {
2376		size_t shsize;
2377
2378		shsize = slab_sizeof(keg->uk_ipers);
2379		keg->uk_pgoff = (PAGE_SIZE * keg->uk_ppera) - shsize;
2380		/*
2381		 * The only way the following is possible is if with our
2382		 * UMA_ALIGN_PTR adjustments we are now bigger than
2383		 * UMA_SLAB_SIZE.  I haven't checked whether this is
2384		 * mathematically possible for all cases, so we make
2385		 * sure here anyway.
2386		 */
2387		KASSERT(keg->uk_pgoff + shsize <= PAGE_SIZE * keg->uk_ppera,
2388		    ("zone %s ipers %d rsize %d size %d slab won't fit",
2389		    zone->uz_name, keg->uk_ipers, keg->uk_rsize, keg->uk_size));
2390	}
2391
2392	if (keg->uk_flags & UMA_ZFLAG_HASH)
2393		hash_alloc(&keg->uk_hash, 0);
2394
2395	CTR3(KTR_UMA, "keg_ctor %p zone %s(%p)", keg, zone->uz_name, zone);
2396
2397	LIST_INSERT_HEAD(&keg->uk_zones, zone, uz_link);
2398
2399	rw_wlock(&uma_rwlock);
2400	LIST_INSERT_HEAD(&uma_kegs, keg, uk_link);
2401	rw_wunlock(&uma_rwlock);
2402	return (0);
2403}
2404
2405static void
2406zone_kva_available(uma_zone_t zone, void *unused)
2407{
2408	uma_keg_t keg;
2409
2410	if ((zone->uz_flags & UMA_ZFLAG_CACHE) != 0)
2411		return;
2412	KEG_GET(zone, keg);
2413
2414	if (keg->uk_allocf == startup_alloc) {
2415		/* Switch to the real allocator. */
2416		if (keg->uk_flags & UMA_ZONE_PCPU)
2417			keg->uk_allocf = pcpu_page_alloc;
2418		else if ((keg->uk_flags & UMA_ZONE_CONTIG) != 0 &&
2419		    keg->uk_ppera > 1)
2420			keg->uk_allocf = contig_alloc;
2421		else
2422			keg->uk_allocf = page_alloc;
2423	}
2424}
2425
2426static void
2427zone_alloc_counters(uma_zone_t zone, void *unused)
2428{
2429
2430	zone->uz_allocs = counter_u64_alloc(M_WAITOK);
2431	zone->uz_frees = counter_u64_alloc(M_WAITOK);
2432	zone->uz_fails = counter_u64_alloc(M_WAITOK);
2433	zone->uz_xdomain = counter_u64_alloc(M_WAITOK);
2434}
2435
2436static void
2437zone_alloc_sysctl(uma_zone_t zone, void *unused)
2438{
2439	uma_zone_domain_t zdom;
2440	uma_domain_t dom;
2441	uma_keg_t keg;
2442	struct sysctl_oid *oid, *domainoid;
2443	int domains, i, cnt;
2444	static const char *nokeg = "cache zone";
2445	char *c;
2446
2447	/*
2448	 * Make a sysctl safe copy of the zone name by removing
2449	 * any special characters and handling dups by appending
2450	 * an index.
2451	 */
2452	if (zone->uz_namecnt != 0) {
2453		/* Count the number of decimal digits and '_' separator. */
2454		for (i = 1, cnt = zone->uz_namecnt; cnt != 0; i++)
2455			cnt /= 10;
2456		zone->uz_ctlname = malloc(strlen(zone->uz_name) + i + 1,
2457		    M_UMA, M_WAITOK);
2458		sprintf(zone->uz_ctlname, "%s_%d", zone->uz_name,
2459		    zone->uz_namecnt);
2460	} else
2461		zone->uz_ctlname = strdup(zone->uz_name, M_UMA);
2462	for (c = zone->uz_ctlname; *c != '\0'; c++)
2463		if (strchr("./\\ -", *c) != NULL)
2464			*c = '_';
2465
2466	/*
2467	 * Basic parameters at the root.
2468	 */
2469	zone->uz_oid = SYSCTL_ADD_NODE(NULL, SYSCTL_STATIC_CHILDREN(_vm_uma),
2470	    OID_AUTO, zone->uz_ctlname, CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
2471	oid = zone->uz_oid;
2472	SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2473	    "size", CTLFLAG_RD, &zone->uz_size, 0, "Allocation size");
2474	SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2475	    "flags", CTLFLAG_RD | CTLTYPE_STRING | CTLFLAG_MPSAFE,
2476	    zone, 0, sysctl_handle_uma_zone_flags, "A",
2477	    "Allocator configuration flags");
2478	SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2479	    "bucket_size", CTLFLAG_RD, &zone->uz_bucket_size, 0,
2480	    "Desired per-cpu cache size");
2481	SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2482	    "bucket_size_max", CTLFLAG_RD, &zone->uz_bucket_size_max, 0,
2483	    "Maximum allowed per-cpu cache size");
2484
2485	/*
2486	 * keg if present.
2487	 */
2488	if ((zone->uz_flags & UMA_ZFLAG_HASH) == 0)
2489		domains = vm_ndomains;
2490	else
2491		domains = 1;
2492	oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid), OID_AUTO,
2493	    "keg", CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
2494	keg = zone->uz_keg;
2495	if ((zone->uz_flags & UMA_ZFLAG_CACHE) == 0) {
2496		SYSCTL_ADD_CONST_STRING(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2497		    "name", CTLFLAG_RD, keg->uk_name, "Keg name");
2498		SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2499		    "rsize", CTLFLAG_RD, &keg->uk_rsize, 0,
2500		    "Real object size with alignment");
2501		SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2502		    "ppera", CTLFLAG_RD, &keg->uk_ppera, 0,
2503		    "pages per-slab allocation");
2504		SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2505		    "ipers", CTLFLAG_RD, &keg->uk_ipers, 0,
2506		    "items available per-slab");
2507		SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2508		    "align", CTLFLAG_RD, &keg->uk_align, 0,
2509		    "item alignment mask");
2510		SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2511		    "reserve", CTLFLAG_RD, &keg->uk_reserve, 0,
2512		    "number of reserved items");
2513		SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2514		    "efficiency", CTLFLAG_RD | CTLTYPE_INT | CTLFLAG_MPSAFE,
2515		    keg, 0, sysctl_handle_uma_slab_efficiency, "I",
2516		    "Slab utilization (100 - internal fragmentation %)");
2517		domainoid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(oid),
2518		    OID_AUTO, "domain", CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
2519		for (i = 0; i < domains; i++) {
2520			dom = &keg->uk_domain[i];
2521			oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(domainoid),
2522			    OID_AUTO, VM_DOMAIN(i)->vmd_name,
2523			    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
2524			SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2525			    "pages", CTLFLAG_RD, &dom->ud_pages, 0,
2526			    "Total pages currently allocated from VM");
2527			SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2528			    "free_items", CTLFLAG_RD, &dom->ud_free_items, 0,
2529			    "items free in the slab layer");
2530		}
2531	} else
2532		SYSCTL_ADD_CONST_STRING(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2533		    "name", CTLFLAG_RD, nokeg, "Keg name");
2534
2535	/*
2536	 * Information about zone limits.
2537	 */
2538	oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid), OID_AUTO,
2539	    "limit", CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
2540	SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2541	    "items", CTLFLAG_RD | CTLTYPE_U64 | CTLFLAG_MPSAFE,
2542	    zone, 0, sysctl_handle_uma_zone_items, "QU",
2543	    "Current number of allocated items if limit is set");
2544	SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2545	    "max_items", CTLFLAG_RD, &zone->uz_max_items, 0,
2546	    "Maximum number of allocated and cached items");
2547	SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2548	    "sleepers", CTLFLAG_RD, &zone->uz_sleepers, 0,
2549	    "Number of threads sleeping at limit");
2550	SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2551	    "sleeps", CTLFLAG_RD, &zone->uz_sleeps, 0,
2552	    "Total zone limit sleeps");
2553	SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2554	    "bucket_max", CTLFLAG_RD, &zone->uz_bucket_max, 0,
2555	    "Maximum number of items in each domain's bucket cache");
2556
2557	/*
2558	 * Per-domain zone information.
2559	 */
2560	domainoid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid),
2561	    OID_AUTO, "domain", CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
2562	for (i = 0; i < domains; i++) {
2563		zdom = ZDOM_GET(zone, i);
2564		oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(domainoid),
2565		    OID_AUTO, VM_DOMAIN(i)->vmd_name,
2566		    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
2567		SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2568		    "nitems", CTLFLAG_RD, &zdom->uzd_nitems,
2569		    "number of items in this domain");
2570		SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2571		    "imax", CTLFLAG_RD, &zdom->uzd_imax,
2572		    "maximum item count in this period");
2573		SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2574		    "imin", CTLFLAG_RD, &zdom->uzd_imin,
2575		    "minimum item count in this period");
2576		SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2577		    "bimin", CTLFLAG_RD, &zdom->uzd_bimin,
2578		    "Minimum item count in this batch");
2579		SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2580		    "wss", CTLFLAG_RD, &zdom->uzd_wss,
2581		    "Working set size");
2582		SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2583		    "limin", CTLFLAG_RD, &zdom->uzd_limin,
2584		    "Long time minimum item count");
2585		SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2586		    "timin", CTLFLAG_RD, &zdom->uzd_timin, 0,
2587		    "Time since zero long time minimum item count");
2588	}
2589
2590	/*
2591	 * General statistics.
2592	 */
2593	oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid), OID_AUTO,
2594	    "stats", CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
2595	SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2596	    "current", CTLFLAG_RD | CTLTYPE_INT | CTLFLAG_MPSAFE,
2597	    zone, 1, sysctl_handle_uma_zone_cur, "I",
2598	    "Current number of allocated items");
2599	SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2600	    "allocs", CTLFLAG_RD | CTLTYPE_U64 | CTLFLAG_MPSAFE,
2601	    zone, 0, sysctl_handle_uma_zone_allocs, "QU",
2602	    "Total allocation calls");
2603	SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2604	    "frees", CTLFLAG_RD | CTLTYPE_U64 | CTLFLAG_MPSAFE,
2605	    zone, 0, sysctl_handle_uma_zone_frees, "QU",
2606	    "Total free calls");
2607	SYSCTL_ADD_COUNTER_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2608	    "fails", CTLFLAG_RD, &zone->uz_fails,
2609	    "Number of allocation failures");
2610	SYSCTL_ADD_COUNTER_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
2611	    "xdomain", CTLFLAG_RD, &zone->uz_xdomain,
2612	    "Free calls from the wrong domain");
2613}
2614
2615struct uma_zone_count {
2616	const char	*name;
2617	int		count;
2618};
2619
2620static void
2621zone_count(uma_zone_t zone, void *arg)
2622{
2623	struct uma_zone_count *cnt;
2624
2625	cnt = arg;
2626	/*
2627	 * Some zones are rapidly created with identical names and
2628	 * destroyed out of order.  This can lead to gaps in the count.
2629	 * Use one greater than the maximum observed for this name.
2630	 */
2631	if (strcmp(zone->uz_name, cnt->name) == 0)
2632		cnt->count = MAX(cnt->count,
2633		    zone->uz_namecnt + 1);
2634}
2635
2636static void
2637zone_update_caches(uma_zone_t zone)
2638{
2639	int i;
2640
2641	for (i = 0; i <= mp_maxid; i++) {
2642		cache_set_uz_size(&zone->uz_cpu[i], zone->uz_size);
2643		cache_set_uz_flags(&zone->uz_cpu[i], zone->uz_flags);
2644	}
2645}
2646
2647/*
2648 * Zone header ctor.  This initializes all fields, locks, etc.
2649 *
2650 * Arguments/Returns follow uma_ctor specifications
2651 *	udata  Actually uma_zctor_args
2652 */
2653static int
2654zone_ctor(void *mem, int size, void *udata, int flags)
2655{
2656	struct uma_zone_count cnt;
2657	struct uma_zctor_args *arg = udata;
2658	uma_zone_domain_t zdom;
2659	uma_zone_t zone = mem;
2660	uma_zone_t z;
2661	uma_keg_t keg;
2662	int i;
2663
2664	bzero(zone, size);
2665	zone->uz_name = arg->name;
2666	zone->uz_ctor = arg->ctor;
2667	zone->uz_dtor = arg->dtor;
2668	zone->uz_init = NULL;
2669	zone->uz_fini = NULL;
2670	zone->uz_sleeps = 0;
2671	zone->uz_bucket_size = 0;
2672	zone->uz_bucket_size_min = 0;
2673	zone->uz_bucket_size_max = BUCKET_MAX;
2674	zone->uz_flags = (arg->flags & UMA_ZONE_SMR);
2675	zone->uz_warning = NULL;
2676	/* The domain structures follow the cpu structures. */
2677	zone->uz_bucket_max = ULONG_MAX;
2678	timevalclear(&zone->uz_ratecheck);
2679
2680	/* Count the number of duplicate names. */
2681	cnt.name = arg->name;
2682	cnt.count = 0;
2683	zone_foreach(zone_count, &cnt);
2684	zone->uz_namecnt = cnt.count;
2685	ZONE_CROSS_LOCK_INIT(zone);
2686
2687	for (i = 0; i < vm_ndomains; i++) {
2688		zdom = ZDOM_GET(zone, i);
2689		ZDOM_LOCK_INIT(zone, zdom, (arg->flags & UMA_ZONE_MTXCLASS));
2690		STAILQ_INIT(&zdom->uzd_buckets);
2691	}
2692
2693#ifdef INVARIANTS
2694	if (arg->uminit == trash_init && arg->fini == trash_fini)
2695		zone->uz_flags |= UMA_ZFLAG_TRASH | UMA_ZFLAG_CTORDTOR;
2696#endif
2697
2698	/*
2699	 * This is a pure cache zone, no kegs.
2700	 */
2701	if (arg->import) {
2702		KASSERT((arg->flags & UMA_ZFLAG_CACHE) != 0,
2703		    ("zone_ctor: Import specified for non-cache zone."));
2704		zone->uz_flags = arg->flags;
2705		zone->uz_size = arg->size;
2706		zone->uz_import = arg->import;
2707		zone->uz_release = arg->release;
2708		zone->uz_arg = arg->arg;
2709#ifdef NUMA
2710		/*
2711		 * Cache zones are round-robin unless a policy is
2712		 * specified because they may have incompatible
2713		 * constraints.
2714		 */
2715		if ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) == 0)
2716			zone->uz_flags |= UMA_ZONE_ROUNDROBIN;
2717#endif
2718		rw_wlock(&uma_rwlock);
2719		LIST_INSERT_HEAD(&uma_cachezones, zone, uz_link);
2720		rw_wunlock(&uma_rwlock);
2721		goto out;
2722	}
2723
2724	/*
2725	 * Use the regular zone/keg/slab allocator.
2726	 */
2727	zone->uz_import = zone_import;
2728	zone->uz_release = zone_release;
2729	zone->uz_arg = zone;
2730	keg = arg->keg;
2731
2732	if (arg->flags & UMA_ZONE_SECONDARY) {
2733		KASSERT((zone->uz_flags & UMA_ZONE_SECONDARY) == 0,
2734		    ("Secondary zone requested UMA_ZFLAG_INTERNAL"));
2735		KASSERT(arg->keg != NULL, ("Secondary zone on zero'd keg"));
2736		zone->uz_init = arg->uminit;
2737		zone->uz_fini = arg->fini;
2738		zone->uz_flags |= UMA_ZONE_SECONDARY;
2739		rw_wlock(&uma_rwlock);
2740		ZONE_LOCK(zone);
2741		LIST_FOREACH(z, &keg->uk_zones, uz_link) {
2742			if (LIST_NEXT(z, uz_link) == NULL) {
2743				LIST_INSERT_AFTER(z, zone, uz_link);
2744				break;
2745			}
2746		}
2747		ZONE_UNLOCK(zone);
2748		rw_wunlock(&uma_rwlock);
2749	} else if (keg == NULL) {
2750		if ((keg = uma_kcreate(zone, arg->size, arg->uminit, arg->fini,
2751		    arg->align, arg->flags)) == NULL)
2752			return (ENOMEM);
2753	} else {
2754		struct uma_kctor_args karg;
2755		int error;
2756
2757		/* We should only be here from uma_startup() */
2758		karg.size = arg->size;
2759		karg.uminit = arg->uminit;
2760		karg.fini = arg->fini;
2761		karg.align = arg->align;
2762		karg.flags = (arg->flags & ~UMA_ZONE_SMR);
2763		karg.zone = zone;
2764		error = keg_ctor(arg->keg, sizeof(struct uma_keg), &karg,
2765		    flags);
2766		if (error)
2767			return (error);
2768	}
2769
2770	/* Inherit properties from the keg. */
2771	zone->uz_keg = keg;
2772	zone->uz_size = keg->uk_size;
2773	zone->uz_flags |= (keg->uk_flags &
2774	    (UMA_ZONE_INHERIT | UMA_ZFLAG_INHERIT));
2775
2776out:
2777	if (booted >= BOOT_PCPU) {
2778		zone_alloc_counters(zone, NULL);
2779		if (booted >= BOOT_RUNNING)
2780			zone_alloc_sysctl(zone, NULL);
2781	} else {
2782		zone->uz_allocs = EARLY_COUNTER;
2783		zone->uz_frees = EARLY_COUNTER;
2784		zone->uz_fails = EARLY_COUNTER;
2785	}
2786
2787	/* Caller requests a private SMR context. */
2788	if ((zone->uz_flags & UMA_ZONE_SMR) != 0)
2789		zone->uz_smr = smr_create(zone->uz_name, 0, 0);
2790
2791	KASSERT((arg->flags & (UMA_ZONE_MAXBUCKET | UMA_ZONE_NOBUCKET)) !=
2792	    (UMA_ZONE_MAXBUCKET | UMA_ZONE_NOBUCKET),
2793	    ("Invalid zone flag combination"));
2794	if (arg->flags & UMA_ZFLAG_INTERNAL)
2795		zone->uz_bucket_size_max = zone->uz_bucket_size = 0;
2796	if ((arg->flags & UMA_ZONE_MAXBUCKET) != 0)
2797		zone->uz_bucket_size = BUCKET_MAX;
2798	else if ((arg->flags & UMA_ZONE_NOBUCKET) != 0)
2799		zone->uz_bucket_size = 0;
2800	else
2801		zone->uz_bucket_size = bucket_select(zone->uz_size);
2802	zone->uz_bucket_size_min = zone->uz_bucket_size;
2803	if (zone->uz_dtor != NULL || zone->uz_ctor != NULL)
2804		zone->uz_flags |= UMA_ZFLAG_CTORDTOR;
2805	zone_update_caches(zone);
2806
2807	return (0);
2808}
2809
2810/*
2811 * Keg header dtor.  This frees all data, destroys locks, frees the hash
2812 * table and removes the keg from the global list.
2813 *
2814 * Arguments/Returns follow uma_dtor specifications
2815 *	udata  unused
2816 */
2817static void
2818keg_dtor(void *arg, int size, void *udata)
2819{
2820	uma_keg_t keg;
2821	uint32_t free, pages;
2822	int i;
2823
2824	keg = (uma_keg_t)arg;
2825	free = pages = 0;
2826	for (i = 0; i < vm_ndomains; i++) {
2827		free += keg->uk_domain[i].ud_free_items;
2828		pages += keg->uk_domain[i].ud_pages;
2829		KEG_LOCK_FINI(keg, i);
2830	}
2831	if (pages != 0)
2832		printf("Freed UMA keg (%s) was not empty (%u items). "
2833		    " Lost %u pages of memory.\n",
2834		    keg->uk_name ? keg->uk_name : "",
2835		    pages / keg->uk_ppera * keg->uk_ipers - free, pages);
2836
2837	hash_free(&keg->uk_hash);
2838}
2839
2840/*
2841 * Zone header dtor.
2842 *
2843 * Arguments/Returns follow uma_dtor specifications
2844 *	udata  unused
2845 */
2846static void
2847zone_dtor(void *arg, int size, void *udata)
2848{
2849	uma_zone_t zone;
2850	uma_keg_t keg;
2851	int i;
2852
2853	zone = (uma_zone_t)arg;
2854
2855	sysctl_remove_oid(zone->uz_oid, 1, 1);
2856
2857	if (!(zone->uz_flags & UMA_ZFLAG_INTERNAL))
2858		cache_drain(zone);
2859
2860	rw_wlock(&uma_rwlock);
2861	LIST_REMOVE(zone, uz_link);
2862	rw_wunlock(&uma_rwlock);
2863	if ((zone->uz_flags & (UMA_ZONE_SECONDARY | UMA_ZFLAG_CACHE)) == 0) {
2864		keg = zone->uz_keg;
2865		keg->uk_reserve = 0;
2866	}
2867	zone_reclaim(zone, UMA_ANYDOMAIN, M_WAITOK, true);
2868
2869	/*
2870	 * We only destroy kegs from non secondary/non cache zones.
2871	 */
2872	if ((zone->uz_flags & (UMA_ZONE_SECONDARY | UMA_ZFLAG_CACHE)) == 0) {
2873		keg = zone->uz_keg;
2874		rw_wlock(&uma_rwlock);
2875		LIST_REMOVE(keg, uk_link);
2876		rw_wunlock(&uma_rwlock);
2877		zone_free_item(kegs, keg, NULL, SKIP_NONE);
2878	}
2879	counter_u64_free(zone->uz_allocs);
2880	counter_u64_free(zone->uz_frees);
2881	counter_u64_free(zone->uz_fails);
2882	counter_u64_free(zone->uz_xdomain);
2883	free(zone->uz_ctlname, M_UMA);
2884	for (i = 0; i < vm_ndomains; i++)
2885		ZDOM_LOCK_FINI(ZDOM_GET(zone, i));
2886	ZONE_CROSS_LOCK_FINI(zone);
2887}
2888
2889static void
2890zone_foreach_unlocked(void (*zfunc)(uma_zone_t, void *arg), void *arg)
2891{
2892	uma_keg_t keg;
2893	uma_zone_t zone;
2894
2895	LIST_FOREACH(keg, &uma_kegs, uk_link) {
2896		LIST_FOREACH(zone, &keg->uk_zones, uz_link)
2897			zfunc(zone, arg);
2898	}
2899	LIST_FOREACH(zone, &uma_cachezones, uz_link)
2900		zfunc(zone, arg);
2901}
2902
2903/*
2904 * Traverses every zone in the system and calls a callback
2905 *
2906 * Arguments:
2907 *	zfunc  A pointer to a function which accepts a zone
2908 *		as an argument.
2909 *
2910 * Returns:
2911 *	Nothing
2912 */
2913static void
2914zone_foreach(void (*zfunc)(uma_zone_t, void *arg), void *arg)
2915{
2916
2917	rw_rlock(&uma_rwlock);
2918	zone_foreach_unlocked(zfunc, arg);
2919	rw_runlock(&uma_rwlock);
2920}
2921
2922/*
2923 * Initialize the kernel memory allocator.  This is done after pages can be
2924 * allocated but before general KVA is available.
2925 */
2926void
2927uma_startup1(vm_offset_t virtual_avail)
2928{
2929	struct uma_zctor_args args;
2930	size_t ksize, zsize, size;
2931	uma_keg_t primarykeg;
2932	uintptr_t m;
2933	int domain;
2934	uint8_t pflag;
2935
2936	bootstart = bootmem = virtual_avail;
2937
2938	rw_init(&uma_rwlock, "UMA lock");
2939	sx_init(&uma_reclaim_lock, "umareclaim");
2940
2941	ksize = sizeof(struct uma_keg) +
2942	    (sizeof(struct uma_domain) * vm_ndomains);
2943	ksize = roundup(ksize, UMA_SUPER_ALIGN);
2944	zsize = sizeof(struct uma_zone) +
2945	    (sizeof(struct uma_cache) * (mp_maxid + 1)) +
2946	    (sizeof(struct uma_zone_domain) * vm_ndomains);
2947	zsize = roundup(zsize, UMA_SUPER_ALIGN);
2948
2949	/* Allocate the zone of zones, zone of kegs, and zone of zones keg. */
2950	size = (zsize * 2) + ksize;
2951	for (domain = 0; domain < vm_ndomains; domain++) {
2952		m = (uintptr_t)startup_alloc(NULL, size, domain, &pflag,
2953		    M_NOWAIT | M_ZERO);
2954		if (m != 0)
2955			break;
2956	}
2957	zones = (uma_zone_t)m;
2958	m += zsize;
2959	kegs = (uma_zone_t)m;
2960	m += zsize;
2961	primarykeg = (uma_keg_t)m;
2962
2963	/* "manually" create the initial zone */
2964	memset(&args, 0, sizeof(args));
2965	args.name = "UMA Kegs";
2966	args.size = ksize;
2967	args.ctor = keg_ctor;
2968	args.dtor = keg_dtor;
2969	args.uminit = zero_init;
2970	args.fini = NULL;
2971	args.keg = primarykeg;
2972	args.align = UMA_SUPER_ALIGN - 1;
2973	args.flags = UMA_ZFLAG_INTERNAL;
2974	zone_ctor(kegs, zsize, &args, M_WAITOK);
2975
2976	args.name = "UMA Zones";
2977	args.size = zsize;
2978	args.ctor = zone_ctor;
2979	args.dtor = zone_dtor;
2980	args.uminit = zero_init;
2981	args.fini = NULL;
2982	args.keg = NULL;
2983	args.align = UMA_SUPER_ALIGN - 1;
2984	args.flags = UMA_ZFLAG_INTERNAL;
2985	zone_ctor(zones, zsize, &args, M_WAITOK);
2986
2987	/* Now make zones for slab headers */
2988	slabzones[0] = uma_zcreate("UMA Slabs 0", SLABZONE0_SIZE,
2989	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
2990	slabzones[1] = uma_zcreate("UMA Slabs 1", SLABZONE1_SIZE,
2991	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
2992
2993	hashzone = uma_zcreate("UMA Hash",
2994	    sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT,
2995	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
2996
2997	bucket_init();
2998	smr_init();
2999}
3000
3001#ifndef UMA_MD_SMALL_ALLOC
3002extern void vm_radix_reserve_kva(void);
3003#endif
3004
3005/*
3006 * Advertise the availability of normal kva allocations and switch to
3007 * the default back-end allocator.  Marks the KVA we consumed on startup
3008 * as used in the map.
3009 */
3010void
3011uma_startup2(void)
3012{
3013
3014	if (bootstart != bootmem) {
3015		vm_map_lock(kernel_map);
3016		(void)vm_map_insert(kernel_map, NULL, 0, bootstart, bootmem,
3017		    VM_PROT_RW, VM_PROT_RW, MAP_NOFAULT);
3018		vm_map_unlock(kernel_map);
3019	}
3020
3021#ifndef UMA_MD_SMALL_ALLOC
3022	/* Set up radix zone to use noobj_alloc. */
3023	vm_radix_reserve_kva();
3024#endif
3025
3026	booted = BOOT_KVA;
3027	zone_foreach_unlocked(zone_kva_available, NULL);
3028	bucket_enable();
3029}
3030
3031/*
3032 * Allocate counters as early as possible so that boot-time allocations are
3033 * accounted more precisely.
3034 */
3035static void
3036uma_startup_pcpu(void *arg __unused)
3037{
3038
3039	zone_foreach_unlocked(zone_alloc_counters, NULL);
3040	booted = BOOT_PCPU;
3041}
3042SYSINIT(uma_startup_pcpu, SI_SUB_COUNTER, SI_ORDER_ANY, uma_startup_pcpu, NULL);
3043
3044/*
3045 * Finish our initialization steps.
3046 */
3047static void
3048uma_startup3(void *arg __unused)
3049{
3050
3051#ifdef INVARIANTS
3052	TUNABLE_INT_FETCH("vm.debug.divisor", &dbg_divisor);
3053	uma_dbg_cnt = counter_u64_alloc(M_WAITOK);
3054	uma_skip_cnt = counter_u64_alloc(M_WAITOK);
3055#endif
3056	zone_foreach_unlocked(zone_alloc_sysctl, NULL);
3057	callout_init(&uma_callout, 1);
3058	callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
3059	booted = BOOT_RUNNING;
3060
3061	EVENTHANDLER_REGISTER(shutdown_post_sync, uma_shutdown, NULL,
3062	    EVENTHANDLER_PRI_FIRST);
3063}
3064SYSINIT(uma_startup3, SI_SUB_VM_CONF, SI_ORDER_SECOND, uma_startup3, NULL);
3065
3066static void
3067uma_shutdown(void)
3068{
3069
3070	booted = BOOT_SHUTDOWN;
3071}
3072
3073static uma_keg_t
3074uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini,
3075		int align, uint32_t flags)
3076{
3077	struct uma_kctor_args args;
3078
3079	args.size = size;
3080	args.uminit = uminit;
3081	args.fini = fini;
3082	args.align = (align == UMA_ALIGN_CACHE) ? uma_align_cache : align;
3083	args.flags = flags;
3084	args.zone = zone;
3085	return (zone_alloc_item(kegs, &args, UMA_ANYDOMAIN, M_WAITOK));
3086}
3087
3088/* Public functions */
3089/* See uma.h */
3090void
3091uma_set_align(int align)
3092{
3093
3094	if (align != UMA_ALIGN_CACHE)
3095		uma_align_cache = align;
3096}
3097
3098/* See uma.h */
3099uma_zone_t
3100uma_zcreate(const char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
3101		uma_init uminit, uma_fini fini, int align, uint32_t flags)
3102
3103{
3104	struct uma_zctor_args args;
3105	uma_zone_t res;
3106
3107	KASSERT(powerof2(align + 1), ("invalid zone alignment %d for \"%s\"",
3108	    align, name));
3109
3110	/* This stuff is essential for the zone ctor */
3111	memset(&args, 0, sizeof(args));
3112	args.name = name;
3113	args.size = size;
3114	args.ctor = ctor;
3115	args.dtor = dtor;
3116	args.uminit = uminit;
3117	args.fini = fini;
3118#ifdef  INVARIANTS
3119	/*
3120	 * Inject procedures which check for memory use after free if we are
3121	 * allowed to scramble the memory while it is not allocated.  This
3122	 * requires that: UMA is actually able to access the memory, no init
3123	 * or fini procedures, no dependency on the initial value of the
3124	 * memory, and no (legitimate) use of the memory after free.  Note,
3125	 * the ctor and dtor do not need to be empty.
3126	 */
3127	if ((!(flags & (UMA_ZONE_ZINIT | UMA_ZONE_NOTOUCH |
3128	    UMA_ZONE_NOFREE))) && uminit == NULL && fini == NULL) {
3129		args.uminit = trash_init;
3130		args.fini = trash_fini;
3131	}
3132#endif
3133	args.align = align;
3134	args.flags = flags;
3135	args.keg = NULL;
3136
3137	sx_xlock(&uma_reclaim_lock);
3138	res = zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK);
3139	sx_xunlock(&uma_reclaim_lock);
3140
3141	return (res);
3142}
3143
3144/* See uma.h */
3145uma_zone_t
3146uma_zsecond_create(const char *name, uma_ctor ctor, uma_dtor dtor,
3147    uma_init zinit, uma_fini zfini, uma_zone_t primary)
3148{
3149	struct uma_zctor_args args;
3150	uma_keg_t keg;
3151	uma_zone_t res;
3152
3153	keg = primary->uz_keg;
3154	memset(&args, 0, sizeof(args));
3155	args.name = name;
3156	args.size = keg->uk_size;
3157	args.ctor = ctor;
3158	args.dtor = dtor;
3159	args.uminit = zinit;
3160	args.fini = zfini;
3161	args.align = keg->uk_align;
3162	args.flags = keg->uk_flags | UMA_ZONE_SECONDARY;
3163	args.keg = keg;
3164
3165	sx_xlock(&uma_reclaim_lock);
3166	res = zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK);
3167	sx_xunlock(&uma_reclaim_lock);
3168
3169	return (res);
3170}
3171
3172/* See uma.h */
3173uma_zone_t
3174uma_zcache_create(const char *name, int size, uma_ctor ctor, uma_dtor dtor,
3175    uma_init zinit, uma_fini zfini, uma_import zimport, uma_release zrelease,
3176    void *arg, int flags)
3177{
3178	struct uma_zctor_args args;
3179
3180	memset(&args, 0, sizeof(args));
3181	args.name = name;
3182	args.size = size;
3183	args.ctor = ctor;
3184	args.dtor = dtor;
3185	args.uminit = zinit;
3186	args.fini = zfini;
3187	args.import = zimport;
3188	args.release = zrelease;
3189	args.arg = arg;
3190	args.align = 0;
3191	args.flags = flags | UMA_ZFLAG_CACHE;
3192
3193	return (zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK));
3194}
3195
3196/* See uma.h */
3197void
3198uma_zdestroy(uma_zone_t zone)
3199{
3200
3201	/*
3202	 * Large slabs are expensive to reclaim, so don't bother doing
3203	 * unnecessary work if we're shutting down.
3204	 */
3205	if (booted == BOOT_SHUTDOWN &&
3206	    zone->uz_fini == NULL && zone->uz_release == zone_release)
3207		return;
3208	sx_xlock(&uma_reclaim_lock);
3209	zone_free_item(zones, zone, NULL, SKIP_NONE);
3210	sx_xunlock(&uma_reclaim_lock);
3211}
3212
3213void
3214uma_zwait(uma_zone_t zone)
3215{
3216
3217	if ((zone->uz_flags & UMA_ZONE_SMR) != 0)
3218		uma_zfree_smr(zone, uma_zalloc_smr(zone, M_WAITOK));
3219	else if ((zone->uz_flags & UMA_ZONE_PCPU) != 0)
3220		uma_zfree_pcpu(zone, uma_zalloc_pcpu(zone, M_WAITOK));
3221	else
3222		uma_zfree(zone, uma_zalloc(zone, M_WAITOK));
3223}
3224
3225void *
3226uma_zalloc_pcpu_arg(uma_zone_t zone, void *udata, int flags)
3227{
3228	void *item, *pcpu_item;
3229#ifdef SMP
3230	int i;
3231
3232	MPASS(zone->uz_flags & UMA_ZONE_PCPU);
3233#endif
3234	item = uma_zalloc_arg(zone, udata, flags & ~M_ZERO);
3235	if (item == NULL)
3236		return (NULL);
3237	pcpu_item = zpcpu_base_to_offset(item);
3238	if (flags & M_ZERO) {
3239#ifdef SMP
3240		for (i = 0; i <= mp_maxid; i++)
3241			bzero(zpcpu_get_cpu(pcpu_item, i), zone->uz_size);
3242#else
3243		bzero(item, zone->uz_size);
3244#endif
3245	}
3246	return (pcpu_item);
3247}
3248
3249/*
3250 * A stub while both regular and pcpu cases are identical.
3251 */
3252void
3253uma_zfree_pcpu_arg(uma_zone_t zone, void *pcpu_item, void *udata)
3254{
3255	void *item;
3256
3257#ifdef SMP
3258	MPASS(zone->uz_flags & UMA_ZONE_PCPU);
3259#endif
3260
3261        /* uma_zfree_pcu_*(..., NULL) does nothing, to match free(9). */
3262        if (pcpu_item == NULL)
3263                return;
3264
3265	item = zpcpu_offset_to_base(pcpu_item);
3266	uma_zfree_arg(zone, item, udata);
3267}
3268
3269static inline void *
3270item_ctor(uma_zone_t zone, int uz_flags, int size, void *udata, int flags,
3271    void *item)
3272{
3273#ifdef INVARIANTS
3274	bool skipdbg;
3275
3276	skipdbg = uma_dbg_zskip(zone, item);
3277	if (!skipdbg && (zone->uz_flags & UMA_ZFLAG_TRASH) != 0 &&
3278	    zone->uz_ctor != trash_ctor)
3279		trash_ctor(item, size, udata, flags);
3280#endif
3281	/* Check flags before loading ctor pointer. */
3282	if (__predict_false((uz_flags & UMA_ZFLAG_CTORDTOR) != 0) &&
3283	    __predict_false(zone->uz_ctor != NULL) &&
3284	    zone->uz_ctor(item, size, udata, flags) != 0) {
3285		counter_u64_add(zone->uz_fails, 1);
3286		zone_free_item(zone, item, udata, SKIP_DTOR | SKIP_CNT);
3287		return (NULL);
3288	}
3289#ifdef INVARIANTS
3290	if (!skipdbg)
3291		uma_dbg_alloc(zone, NULL, item);
3292#endif
3293	if (__predict_false(flags & M_ZERO))
3294		return (memset(item, 0, size));
3295
3296	return (item);
3297}
3298
3299static inline void
3300item_dtor(uma_zone_t zone, void *item, int size, void *udata,
3301    enum zfreeskip skip)
3302{
3303#ifdef INVARIANTS
3304	bool skipdbg;
3305
3306	skipdbg = uma_dbg_zskip(zone, item);
3307	if (skip == SKIP_NONE && !skipdbg) {
3308		if ((zone->uz_flags & UMA_ZONE_MALLOC) != 0)
3309			uma_dbg_free(zone, udata, item);
3310		else
3311			uma_dbg_free(zone, NULL, item);
3312	}
3313#endif
3314	if (__predict_true(skip < SKIP_DTOR)) {
3315		if (zone->uz_dtor != NULL)
3316			zone->uz_dtor(item, size, udata);
3317#ifdef INVARIANTS
3318		if (!skipdbg && (zone->uz_flags & UMA_ZFLAG_TRASH) != 0 &&
3319		    zone->uz_dtor != trash_dtor)
3320			trash_dtor(item, size, udata);
3321#endif
3322	}
3323}
3324
3325#ifdef NUMA
3326static int
3327item_domain(void *item)
3328{
3329	int domain;
3330
3331	domain = vm_phys_domain(vtophys(item));
3332	KASSERT(domain >= 0 && domain < vm_ndomains,
3333	    ("%s: unknown domain for item %p", __func__, item));
3334	return (domain);
3335}
3336#endif
3337
3338#if defined(INVARIANTS) || defined(DEBUG_MEMGUARD) || defined(WITNESS)
3339#define	UMA_ZALLOC_DEBUG
3340static int
3341uma_zalloc_debug(uma_zone_t zone, void **itemp, void *udata, int flags)
3342{
3343	int error;
3344
3345	error = 0;
3346#ifdef WITNESS
3347	if (flags & M_WAITOK) {
3348		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
3349		    "uma_zalloc_debug: zone \"%s\"", zone->uz_name);
3350	}
3351#endif
3352
3353#ifdef INVARIANTS
3354	KASSERT((flags & M_EXEC) == 0,
3355	    ("uma_zalloc_debug: called with M_EXEC"));
3356	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
3357	    ("uma_zalloc_debug: called within spinlock or critical section"));
3358	KASSERT((zone->uz_flags & UMA_ZONE_PCPU) == 0 || (flags & M_ZERO) == 0,
3359	    ("uma_zalloc_debug: allocating from a pcpu zone with M_ZERO"));
3360#endif
3361
3362#ifdef DEBUG_MEMGUARD
3363	if ((zone->uz_flags & UMA_ZONE_SMR) == 0 && memguard_cmp_zone(zone)) {
3364		void *item;
3365		item = memguard_alloc(zone->uz_size, flags);
3366		if (item != NULL) {
3367			error = EJUSTRETURN;
3368			if (zone->uz_init != NULL &&
3369			    zone->uz_init(item, zone->uz_size, flags) != 0) {
3370				*itemp = NULL;
3371				return (error);
3372			}
3373			if (zone->uz_ctor != NULL &&
3374			    zone->uz_ctor(item, zone->uz_size, udata,
3375			    flags) != 0) {
3376				counter_u64_add(zone->uz_fails, 1);
3377			    	zone->uz_fini(item, zone->uz_size);
3378				*itemp = NULL;
3379				return (error);
3380			}
3381			*itemp = item;
3382			return (error);
3383		}
3384		/* This is unfortunate but should not be fatal. */
3385	}
3386#endif
3387	return (error);
3388}
3389
3390static int
3391uma_zfree_debug(uma_zone_t zone, void *item, void *udata)
3392{
3393	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
3394	    ("uma_zfree_debug: called with spinlock or critical section held"));
3395
3396#ifdef DEBUG_MEMGUARD
3397	if ((zone->uz_flags & UMA_ZONE_SMR) == 0 && is_memguard_addr(item)) {
3398		if (zone->uz_dtor != NULL)
3399			zone->uz_dtor(item, zone->uz_size, udata);
3400		if (zone->uz_fini != NULL)
3401			zone->uz_fini(item, zone->uz_size);
3402		memguard_free(item);
3403		return (EJUSTRETURN);
3404	}
3405#endif
3406	return (0);
3407}
3408#endif
3409
3410static inline void *
3411cache_alloc_item(uma_zone_t zone, uma_cache_t cache, uma_cache_bucket_t bucket,
3412    void *udata, int flags)
3413{
3414	void *item;
3415	int size, uz_flags;
3416
3417	item = cache_bucket_pop(cache, bucket);
3418	size = cache_uz_size(cache);
3419	uz_flags = cache_uz_flags(cache);
3420	critical_exit();
3421	return (item_ctor(zone, uz_flags, size, udata, flags, item));
3422}
3423
3424static __noinline void *
3425cache_alloc_retry(uma_zone_t zone, uma_cache_t cache, void *udata, int flags)
3426{
3427	uma_cache_bucket_t bucket;
3428	int domain;
3429
3430	while (cache_alloc(zone, cache, udata, flags)) {
3431		cache = &zone->uz_cpu[curcpu];
3432		bucket = &cache->uc_allocbucket;
3433		if (__predict_false(bucket->ucb_cnt == 0))
3434			continue;
3435		return (cache_alloc_item(zone, cache, bucket, udata, flags));
3436	}
3437	critical_exit();
3438
3439	/*
3440	 * We can not get a bucket so try to return a single item.
3441	 */
3442	if (zone->uz_flags & UMA_ZONE_FIRSTTOUCH)
3443		domain = PCPU_GET(domain);
3444	else
3445		domain = UMA_ANYDOMAIN;
3446	return (zone_alloc_item(zone, udata, domain, flags));
3447}
3448
3449/* See uma.h */
3450void *
3451uma_zalloc_smr(uma_zone_t zone, int flags)
3452{
3453	uma_cache_bucket_t bucket;
3454	uma_cache_t cache;
3455
3456#ifdef UMA_ZALLOC_DEBUG
3457	void *item;
3458
3459	KASSERT((zone->uz_flags & UMA_ZONE_SMR) != 0,
3460	    ("uma_zalloc_arg: called with non-SMR zone."));
3461	if (uma_zalloc_debug(zone, &item, NULL, flags) == EJUSTRETURN)
3462		return (item);
3463#endif
3464
3465	critical_enter();
3466	cache = &zone->uz_cpu[curcpu];
3467	bucket = &cache->uc_allocbucket;
3468	if (__predict_false(bucket->ucb_cnt == 0))
3469		return (cache_alloc_retry(zone, cache, NULL, flags));
3470	return (cache_alloc_item(zone, cache, bucket, NULL, flags));
3471}
3472
3473/* See uma.h */
3474void *
3475uma_zalloc_arg(uma_zone_t zone, void *udata, int flags)
3476{
3477	uma_cache_bucket_t bucket;
3478	uma_cache_t cache;
3479
3480	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
3481	random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
3482
3483	/* This is the fast path allocation */
3484	CTR3(KTR_UMA, "uma_zalloc_arg zone %s(%p) flags %d", zone->uz_name,
3485	    zone, flags);
3486
3487#ifdef UMA_ZALLOC_DEBUG
3488	void *item;
3489
3490	KASSERT((zone->uz_flags & UMA_ZONE_SMR) == 0,
3491	    ("uma_zalloc_arg: called with SMR zone."));
3492	if (uma_zalloc_debug(zone, &item, udata, flags) == EJUSTRETURN)
3493		return (item);
3494#endif
3495
3496	/*
3497	 * If possible, allocate from the per-CPU cache.  There are two
3498	 * requirements for safe access to the per-CPU cache: (1) the thread
3499	 * accessing the cache must not be preempted or yield during access,
3500	 * and (2) the thread must not migrate CPUs without switching which
3501	 * cache it accesses.  We rely on a critical section to prevent
3502	 * preemption and migration.  We release the critical section in
3503	 * order to acquire the zone mutex if we are unable to allocate from
3504	 * the current cache; when we re-acquire the critical section, we
3505	 * must detect and handle migration if it has occurred.
3506	 */
3507	critical_enter();
3508	cache = &zone->uz_cpu[curcpu];
3509	bucket = &cache->uc_allocbucket;
3510	if (__predict_false(bucket->ucb_cnt == 0))
3511		return (cache_alloc_retry(zone, cache, udata, flags));
3512	return (cache_alloc_item(zone, cache, bucket, udata, flags));
3513}
3514
3515/*
3516 * Replenish an alloc bucket and possibly restore an old one.  Called in
3517 * a critical section.  Returns in a critical section.
3518 *
3519 * A false return value indicates an allocation failure.
3520 * A true return value indicates success and the caller should retry.
3521 */
3522static __noinline bool
3523cache_alloc(uma_zone_t zone, uma_cache_t cache, void *udata, int flags)
3524{
3525	uma_bucket_t bucket;
3526	int curdomain, domain;
3527	bool new;
3528
3529	CRITICAL_ASSERT(curthread);
3530
3531	/*
3532	 * If we have run out of items in our alloc bucket see
3533	 * if we can switch with the free bucket.
3534	 *
3535	 * SMR Zones can't re-use the free bucket until the sequence has
3536	 * expired.
3537	 */
3538	if ((cache_uz_flags(cache) & UMA_ZONE_SMR) == 0 &&
3539	    cache->uc_freebucket.ucb_cnt != 0) {
3540		cache_bucket_swap(&cache->uc_freebucket,
3541		    &cache->uc_allocbucket);
3542		return (true);
3543	}
3544
3545	/*
3546	 * Discard any empty allocation bucket while we hold no locks.
3547	 */
3548	bucket = cache_bucket_unload_alloc(cache);
3549	critical_exit();
3550
3551	if (bucket != NULL) {
3552		KASSERT(bucket->ub_cnt == 0,
3553		    ("cache_alloc: Entered with non-empty alloc bucket."));
3554		bucket_free(zone, bucket, udata);
3555	}
3556
3557	/*
3558	 * Attempt to retrieve the item from the per-CPU cache has failed, so
3559	 * we must go back to the zone.  This requires the zdom lock, so we
3560	 * must drop the critical section, then re-acquire it when we go back
3561	 * to the cache.  Since the critical section is released, we may be
3562	 * preempted or migrate.  As such, make sure not to maintain any
3563	 * thread-local state specific to the cache from prior to releasing
3564	 * the critical section.
3565	 */
3566	domain = PCPU_GET(domain);
3567	if ((cache_uz_flags(cache) & UMA_ZONE_ROUNDROBIN) != 0 ||
3568	    VM_DOMAIN_EMPTY(domain))
3569		domain = zone_domain_highest(zone, domain);
3570	bucket = cache_fetch_bucket(zone, cache, domain);
3571	if (bucket == NULL && zone->uz_bucket_size != 0 && !bucketdisable) {
3572		bucket = zone_alloc_bucket(zone, udata, domain, flags);
3573		new = true;
3574	} else {
3575		new = false;
3576	}
3577
3578	CTR3(KTR_UMA, "uma_zalloc: zone %s(%p) bucket zone returned %p",
3579	    zone->uz_name, zone, bucket);
3580	if (bucket == NULL) {
3581		critical_enter();
3582		return (false);
3583	}
3584
3585	/*
3586	 * See if we lost the race or were migrated.  Cache the
3587	 * initialized bucket to make this less likely or claim
3588	 * the memory directly.
3589	 */
3590	critical_enter();
3591	cache = &zone->uz_cpu[curcpu];
3592	if (cache->uc_allocbucket.ucb_bucket == NULL &&
3593	    ((cache_uz_flags(cache) & UMA_ZONE_FIRSTTOUCH) == 0 ||
3594	    (curdomain = PCPU_GET(domain)) == domain ||
3595	    VM_DOMAIN_EMPTY(curdomain))) {
3596		if (new)
3597			atomic_add_long(&ZDOM_GET(zone, domain)->uzd_imax,
3598			    bucket->ub_cnt);
3599		cache_bucket_load_alloc(cache, bucket);
3600		return (true);
3601	}
3602
3603	/*
3604	 * We lost the race, release this bucket and start over.
3605	 */
3606	critical_exit();
3607	zone_put_bucket(zone, domain, bucket, udata, !new);
3608	critical_enter();
3609
3610	return (true);
3611}
3612
3613void *
3614uma_zalloc_domain(uma_zone_t zone, void *udata, int domain, int flags)
3615{
3616#ifdef NUMA
3617	uma_bucket_t bucket;
3618	uma_zone_domain_t zdom;
3619	void *item;
3620#endif
3621
3622	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
3623	random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
3624
3625	/* This is the fast path allocation */
3626	CTR4(KTR_UMA, "uma_zalloc_domain zone %s(%p) domain %d flags %d",
3627	    zone->uz_name, zone, domain, flags);
3628
3629	if (flags & M_WAITOK) {
3630		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
3631		    "uma_zalloc_domain: zone \"%s\"", zone->uz_name);
3632	}
3633	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
3634	    ("uma_zalloc_domain: called with spinlock or critical section held"));
3635	KASSERT((zone->uz_flags & UMA_ZONE_SMR) == 0,
3636	    ("uma_zalloc_domain: called with SMR zone."));
3637#ifdef NUMA
3638	KASSERT((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) != 0,
3639	    ("uma_zalloc_domain: called with non-FIRSTTOUCH zone."));
3640
3641	if (vm_ndomains == 1)
3642		return (uma_zalloc_arg(zone, udata, flags));
3643
3644	/*
3645	 * Try to allocate from the bucket cache before falling back to the keg.
3646	 * We could try harder and attempt to allocate from per-CPU caches or
3647	 * the per-domain cross-domain buckets, but the complexity is probably
3648	 * not worth it.  It is more important that frees of previous
3649	 * cross-domain allocations do not blow up the cache.
3650	 */
3651	zdom = zone_domain_lock(zone, domain);
3652	if ((bucket = zone_fetch_bucket(zone, zdom, false)) != NULL) {
3653		item = bucket->ub_bucket[bucket->ub_cnt - 1];
3654#ifdef INVARIANTS
3655		bucket->ub_bucket[bucket->ub_cnt - 1] = NULL;
3656#endif
3657		bucket->ub_cnt--;
3658		zone_put_bucket(zone, domain, bucket, udata, true);
3659		item = item_ctor(zone, zone->uz_flags, zone->uz_size, udata,
3660		    flags, item);
3661		if (item != NULL) {
3662			KASSERT(item_domain(item) == domain,
3663			    ("%s: bucket cache item %p from wrong domain",
3664			    __func__, item));
3665			counter_u64_add(zone->uz_allocs, 1);
3666		}
3667		return (item);
3668	}
3669	ZDOM_UNLOCK(zdom);
3670	return (zone_alloc_item(zone, udata, domain, flags));
3671#else
3672	return (uma_zalloc_arg(zone, udata, flags));
3673#endif
3674}
3675
3676/*
3677 * Find a slab with some space.  Prefer slabs that are partially used over those
3678 * that are totally full.  This helps to reduce fragmentation.
3679 *
3680 * If 'rr' is 1, search all domains starting from 'domain'.  Otherwise check
3681 * only 'domain'.
3682 */
3683static uma_slab_t
3684keg_first_slab(uma_keg_t keg, int domain, bool rr)
3685{
3686	uma_domain_t dom;
3687	uma_slab_t slab;
3688	int start;
3689
3690	KASSERT(domain >= 0 && domain < vm_ndomains,
3691	    ("keg_first_slab: domain %d out of range", domain));
3692	KEG_LOCK_ASSERT(keg, domain);
3693
3694	slab = NULL;
3695	start = domain;
3696	do {
3697		dom = &keg->uk_domain[domain];
3698		if ((slab = LIST_FIRST(&dom->ud_part_slab)) != NULL)
3699			return (slab);
3700		if ((slab = LIST_FIRST(&dom->ud_free_slab)) != NULL) {
3701			LIST_REMOVE(slab, us_link);
3702			dom->ud_free_slabs--;
3703			LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
3704			return (slab);
3705		}
3706		if (rr)
3707			domain = (domain + 1) % vm_ndomains;
3708	} while (domain != start);
3709
3710	return (NULL);
3711}
3712
3713/*
3714 * Fetch an existing slab from a free or partial list.  Returns with the
3715 * keg domain lock held if a slab was found or unlocked if not.
3716 */
3717static uma_slab_t
3718keg_fetch_free_slab(uma_keg_t keg, int domain, bool rr, int flags)
3719{
3720	uma_slab_t slab;
3721	uint32_t reserve;
3722
3723	/* HASH has a single free list. */
3724	if ((keg->uk_flags & UMA_ZFLAG_HASH) != 0)
3725		domain = 0;
3726
3727	KEG_LOCK(keg, domain);
3728	reserve = (flags & M_USE_RESERVE) != 0 ? 0 : keg->uk_reserve;
3729	if (keg->uk_domain[domain].ud_free_items <= reserve ||
3730	    (slab = keg_first_slab(keg, domain, rr)) == NULL) {
3731		KEG_UNLOCK(keg, domain);
3732		return (NULL);
3733	}
3734	return (slab);
3735}
3736
3737static uma_slab_t
3738keg_fetch_slab(uma_keg_t keg, uma_zone_t zone, int rdomain, const int flags)
3739{
3740	struct vm_domainset_iter di;
3741	uma_slab_t slab;
3742	int aflags, domain;
3743	bool rr;
3744
3745restart:
3746	/*
3747	 * Use the keg's policy if upper layers haven't already specified a
3748	 * domain (as happens with first-touch zones).
3749	 *
3750	 * To avoid races we run the iterator with the keg lock held, but that
3751	 * means that we cannot allow the vm_domainset layer to sleep.  Thus,
3752	 * clear M_WAITOK and handle low memory conditions locally.
3753	 */
3754	rr = rdomain == UMA_ANYDOMAIN;
3755	if (rr) {
3756		aflags = (flags & ~M_WAITOK) | M_NOWAIT;
3757		vm_domainset_iter_policy_ref_init(&di, &keg->uk_dr, &domain,
3758		    &aflags);
3759	} else {
3760		aflags = flags;
3761		domain = rdomain;
3762	}
3763
3764	for (;;) {
3765		slab = keg_fetch_free_slab(keg, domain, rr, flags);
3766		if (slab != NULL)
3767			return (slab);
3768
3769		/*
3770		 * M_NOVM means don't ask at all!
3771		 */
3772		if (flags & M_NOVM)
3773			break;
3774
3775		slab = keg_alloc_slab(keg, zone, domain, flags, aflags);
3776		if (slab != NULL)
3777			return (slab);
3778		if (!rr && (flags & M_WAITOK) == 0)
3779			break;
3780		if (rr && vm_domainset_iter_policy(&di, &domain) != 0) {
3781			if ((flags & M_WAITOK) != 0) {
3782				vm_wait_doms(&keg->uk_dr.dr_policy->ds_mask, 0);
3783				goto restart;
3784			}
3785			break;
3786		}
3787	}
3788
3789	/*
3790	 * We might not have been able to get a slab but another cpu
3791	 * could have while we were unlocked.  Check again before we
3792	 * fail.
3793	 */
3794	if ((slab = keg_fetch_free_slab(keg, domain, rr, flags)) != NULL)
3795		return (slab);
3796
3797	return (NULL);
3798}
3799
3800static void *
3801slab_alloc_item(uma_keg_t keg, uma_slab_t slab)
3802{
3803	uma_domain_t dom;
3804	void *item;
3805	int freei;
3806
3807	KEG_LOCK_ASSERT(keg, slab->us_domain);
3808
3809	dom = &keg->uk_domain[slab->us_domain];
3810	freei = BIT_FFS(keg->uk_ipers, &slab->us_free) - 1;
3811	BIT_CLR(keg->uk_ipers, freei, &slab->us_free);
3812	item = slab_item(slab, keg, freei);
3813	slab->us_freecount--;
3814	dom->ud_free_items--;
3815
3816	/*
3817	 * Move this slab to the full list.  It must be on the partial list, so
3818	 * we do not need to update the free slab count.  In particular,
3819	 * keg_fetch_slab() always returns slabs on the partial list.
3820	 */
3821	if (slab->us_freecount == 0) {
3822		LIST_REMOVE(slab, us_link);
3823		LIST_INSERT_HEAD(&dom->ud_full_slab, slab, us_link);
3824	}
3825
3826	return (item);
3827}
3828
3829static int
3830zone_import(void *arg, void **bucket, int max, int domain, int flags)
3831{
3832	uma_domain_t dom;
3833	uma_zone_t zone;
3834	uma_slab_t slab;
3835	uma_keg_t keg;
3836#ifdef NUMA
3837	int stripe;
3838#endif
3839	int i;
3840
3841	zone = arg;
3842	slab = NULL;
3843	keg = zone->uz_keg;
3844	/* Try to keep the buckets totally full */
3845	for (i = 0; i < max; ) {
3846		if ((slab = keg_fetch_slab(keg, zone, domain, flags)) == NULL)
3847			break;
3848#ifdef NUMA
3849		stripe = howmany(max, vm_ndomains);
3850#endif
3851		dom = &keg->uk_domain[slab->us_domain];
3852		do {
3853			bucket[i++] = slab_alloc_item(keg, slab);
3854			if (dom->ud_free_items <= keg->uk_reserve) {
3855				/*
3856				 * Avoid depleting the reserve after a
3857				 * successful item allocation, even if
3858				 * M_USE_RESERVE is specified.
3859				 */
3860				KEG_UNLOCK(keg, slab->us_domain);
3861				goto out;
3862			}
3863#ifdef NUMA
3864			/*
3865			 * If the zone is striped we pick a new slab for every
3866			 * N allocations.  Eliminating this conditional will
3867			 * instead pick a new domain for each bucket rather
3868			 * than stripe within each bucket.  The current option
3869			 * produces more fragmentation and requires more cpu
3870			 * time but yields better distribution.
3871			 */
3872			if ((zone->uz_flags & UMA_ZONE_ROUNDROBIN) != 0 &&
3873			    vm_ndomains > 1 && --stripe == 0)
3874				break;
3875#endif
3876		} while (slab->us_freecount != 0 && i < max);
3877		KEG_UNLOCK(keg, slab->us_domain);
3878
3879		/* Don't block if we allocated any successfully. */
3880		flags &= ~M_WAITOK;
3881		flags |= M_NOWAIT;
3882	}
3883out:
3884	return i;
3885}
3886
3887static int
3888zone_alloc_limit_hard(uma_zone_t zone, int count, int flags)
3889{
3890	uint64_t old, new, total, max;
3891
3892	/*
3893	 * The hard case.  We're going to sleep because there were existing
3894	 * sleepers or because we ran out of items.  This routine enforces
3895	 * fairness by keeping fifo order.
3896	 *
3897	 * First release our ill gotten gains and make some noise.
3898	 */
3899	for (;;) {
3900		zone_free_limit(zone, count);
3901		zone_log_warning(zone);
3902		zone_maxaction(zone);
3903		if (flags & M_NOWAIT)
3904			return (0);
3905
3906		/*
3907		 * We need to allocate an item or set ourself as a sleeper
3908		 * while the sleepq lock is held to avoid wakeup races.  This
3909		 * is essentially a home rolled semaphore.
3910		 */
3911		sleepq_lock(&zone->uz_max_items);
3912		old = zone->uz_items;
3913		do {
3914			MPASS(UZ_ITEMS_SLEEPERS(old) < UZ_ITEMS_SLEEPERS_MAX);
3915			/* Cache the max since we will evaluate twice. */
3916			max = zone->uz_max_items;
3917			if (UZ_ITEMS_SLEEPERS(old) != 0 ||
3918			    UZ_ITEMS_COUNT(old) >= max)
3919				new = old + UZ_ITEMS_SLEEPER;
3920			else
3921				new = old + MIN(count, max - old);
3922		} while (atomic_fcmpset_64(&zone->uz_items, &old, new) == 0);
3923
3924		/* We may have successfully allocated under the sleepq lock. */
3925		if (UZ_ITEMS_SLEEPERS(new) == 0) {
3926			sleepq_release(&zone->uz_max_items);
3927			return (new - old);
3928		}
3929
3930		/*
3931		 * This is in a different cacheline from uz_items so that we
3932		 * don't constantly invalidate the fastpath cacheline when we
3933		 * adjust item counts.  This could be limited to toggling on
3934		 * transitions.
3935		 */
3936		atomic_add_32(&zone->uz_sleepers, 1);
3937		atomic_add_64(&zone->uz_sleeps, 1);
3938
3939		/*
3940		 * We have added ourselves as a sleeper.  The sleepq lock
3941		 * protects us from wakeup races.  Sleep now and then retry.
3942		 */
3943		sleepq_add(&zone->uz_max_items, NULL, "zonelimit", 0, 0);
3944		sleepq_wait(&zone->uz_max_items, PVM);
3945
3946		/*
3947		 * After wakeup, remove ourselves as a sleeper and try
3948		 * again.  We no longer have the sleepq lock for protection.
3949		 *
3950		 * Subract ourselves as a sleeper while attempting to add
3951		 * our count.
3952		 */
3953		atomic_subtract_32(&zone->uz_sleepers, 1);
3954		old = atomic_fetchadd_64(&zone->uz_items,
3955		    -(UZ_ITEMS_SLEEPER - count));
3956		/* We're no longer a sleeper. */
3957		old -= UZ_ITEMS_SLEEPER;
3958
3959		/*
3960		 * If we're still at the limit, restart.  Notably do not
3961		 * block on other sleepers.  Cache the max value to protect
3962		 * against changes via sysctl.
3963		 */
3964		total = UZ_ITEMS_COUNT(old);
3965		max = zone->uz_max_items;
3966		if (total >= max)
3967			continue;
3968		/* Truncate if necessary, otherwise wake other sleepers. */
3969		if (total + count > max) {
3970			zone_free_limit(zone, total + count - max);
3971			count = max - total;
3972		} else if (total + count < max && UZ_ITEMS_SLEEPERS(old) != 0)
3973			wakeup_one(&zone->uz_max_items);
3974
3975		return (count);
3976	}
3977}
3978
3979/*
3980 * Allocate 'count' items from our max_items limit.  Returns the number
3981 * available.  If M_NOWAIT is not specified it will sleep until at least
3982 * one item can be allocated.
3983 */
3984static int
3985zone_alloc_limit(uma_zone_t zone, int count, int flags)
3986{
3987	uint64_t old;
3988	uint64_t max;
3989
3990	max = zone->uz_max_items;
3991	MPASS(max > 0);
3992
3993	/*
3994	 * We expect normal allocations to succeed with a simple
3995	 * fetchadd.
3996	 */
3997	old = atomic_fetchadd_64(&zone->uz_items, count);
3998	if (__predict_true(old + count <= max))
3999		return (count);
4000
4001	/*
4002	 * If we had some items and no sleepers just return the
4003	 * truncated value.  We have to release the excess space
4004	 * though because that may wake sleepers who weren't woken
4005	 * because we were temporarily over the limit.
4006	 */
4007	if (old < max) {
4008		zone_free_limit(zone, (old + count) - max);
4009		return (max - old);
4010	}
4011	return (zone_alloc_limit_hard(zone, count, flags));
4012}
4013
4014/*
4015 * Free a number of items back to the limit.
4016 */
4017static void
4018zone_free_limit(uma_zone_t zone, int count)
4019{
4020	uint64_t old;
4021
4022	MPASS(count > 0);
4023
4024	/*
4025	 * In the common case we either have no sleepers or
4026	 * are still over the limit and can just return.
4027	 */
4028	old = atomic_fetchadd_64(&zone->uz_items, -count);
4029	if (__predict_true(UZ_ITEMS_SLEEPERS(old) == 0 ||
4030	   UZ_ITEMS_COUNT(old) - count >= zone->uz_max_items))
4031		return;
4032
4033	/*
4034	 * Moderate the rate of wakeups.  Sleepers will continue
4035	 * to generate wakeups if necessary.
4036	 */
4037	wakeup_one(&zone->uz_max_items);
4038}
4039
4040static uma_bucket_t
4041zone_alloc_bucket(uma_zone_t zone, void *udata, int domain, int flags)
4042{
4043	uma_bucket_t bucket;
4044	int maxbucket, cnt;
4045
4046	CTR3(KTR_UMA, "zone_alloc_bucket zone %s(%p) domain %d", zone->uz_name,
4047	    zone, domain);
4048
4049	/* Avoid allocs targeting empty domains. */
4050	if (domain != UMA_ANYDOMAIN && VM_DOMAIN_EMPTY(domain))
4051		domain = UMA_ANYDOMAIN;
4052	else if ((zone->uz_flags & UMA_ZONE_ROUNDROBIN) != 0)
4053		domain = UMA_ANYDOMAIN;
4054
4055	if (zone->uz_max_items > 0)
4056		maxbucket = zone_alloc_limit(zone, zone->uz_bucket_size,
4057		    M_NOWAIT);
4058	else
4059		maxbucket = zone->uz_bucket_size;
4060	if (maxbucket == 0)
4061		return (false);
4062
4063	/* Don't wait for buckets, preserve caller's NOVM setting. */
4064	bucket = bucket_alloc(zone, udata, M_NOWAIT | (flags & M_NOVM));
4065	if (bucket == NULL) {
4066		cnt = 0;
4067		goto out;
4068	}
4069
4070	bucket->ub_cnt = zone->uz_import(zone->uz_arg, bucket->ub_bucket,
4071	    MIN(maxbucket, bucket->ub_entries), domain, flags);
4072
4073	/*
4074	 * Initialize the memory if necessary.
4075	 */
4076	if (bucket->ub_cnt != 0 && zone->uz_init != NULL) {
4077		int i;
4078
4079		for (i = 0; i < bucket->ub_cnt; i++)
4080			if (zone->uz_init(bucket->ub_bucket[i], zone->uz_size,
4081			    flags) != 0)
4082				break;
4083		/*
4084		 * If we couldn't initialize the whole bucket, put the
4085		 * rest back onto the freelist.
4086		 */
4087		if (i != bucket->ub_cnt) {
4088			zone->uz_release(zone->uz_arg, &bucket->ub_bucket[i],
4089			    bucket->ub_cnt - i);
4090#ifdef INVARIANTS
4091			bzero(&bucket->ub_bucket[i],
4092			    sizeof(void *) * (bucket->ub_cnt - i));
4093#endif
4094			bucket->ub_cnt = i;
4095		}
4096	}
4097
4098	cnt = bucket->ub_cnt;
4099	if (bucket->ub_cnt == 0) {
4100		bucket_free(zone, bucket, udata);
4101		counter_u64_add(zone->uz_fails, 1);
4102		bucket = NULL;
4103	}
4104out:
4105	if (zone->uz_max_items > 0 && cnt < maxbucket)
4106		zone_free_limit(zone, maxbucket - cnt);
4107
4108	return (bucket);
4109}
4110
4111/*
4112 * Allocates a single item from a zone.
4113 *
4114 * Arguments
4115 *	zone   The zone to alloc for.
4116 *	udata  The data to be passed to the constructor.
4117 *	domain The domain to allocate from or UMA_ANYDOMAIN.
4118 *	flags  M_WAITOK, M_NOWAIT, M_ZERO.
4119 *
4120 * Returns
4121 *	NULL if there is no memory and M_NOWAIT is set
4122 *	An item if successful
4123 */
4124
4125static void *
4126zone_alloc_item(uma_zone_t zone, void *udata, int domain, int flags)
4127{
4128	void *item;
4129
4130	if (zone->uz_max_items > 0 && zone_alloc_limit(zone, 1, flags) == 0) {
4131		counter_u64_add(zone->uz_fails, 1);
4132		return (NULL);
4133	}
4134
4135	/* Avoid allocs targeting empty domains. */
4136	if (domain != UMA_ANYDOMAIN && VM_DOMAIN_EMPTY(domain))
4137		domain = UMA_ANYDOMAIN;
4138
4139	if (zone->uz_import(zone->uz_arg, &item, 1, domain, flags) != 1)
4140		goto fail_cnt;
4141
4142	/*
4143	 * We have to call both the zone's init (not the keg's init)
4144	 * and the zone's ctor.  This is because the item is going from
4145	 * a keg slab directly to the user, and the user is expecting it
4146	 * to be both zone-init'd as well as zone-ctor'd.
4147	 */
4148	if (zone->uz_init != NULL) {
4149		if (zone->uz_init(item, zone->uz_size, flags) != 0) {
4150			zone_free_item(zone, item, udata, SKIP_FINI | SKIP_CNT);
4151			goto fail_cnt;
4152		}
4153	}
4154	item = item_ctor(zone, zone->uz_flags, zone->uz_size, udata, flags,
4155	    item);
4156	if (item == NULL)
4157		goto fail;
4158
4159	counter_u64_add(zone->uz_allocs, 1);
4160	CTR3(KTR_UMA, "zone_alloc_item item %p from %s(%p)", item,
4161	    zone->uz_name, zone);
4162
4163	return (item);
4164
4165fail_cnt:
4166	counter_u64_add(zone->uz_fails, 1);
4167fail:
4168	if (zone->uz_max_items > 0)
4169		zone_free_limit(zone, 1);
4170	CTR2(KTR_UMA, "zone_alloc_item failed from %s(%p)",
4171	    zone->uz_name, zone);
4172
4173	return (NULL);
4174}
4175
4176/* See uma.h */
4177void
4178uma_zfree_smr(uma_zone_t zone, void *item)
4179{
4180	uma_cache_t cache;
4181	uma_cache_bucket_t bucket;
4182	int itemdomain, uz_flags;
4183
4184#ifdef UMA_ZALLOC_DEBUG
4185	KASSERT((zone->uz_flags & UMA_ZONE_SMR) != 0,
4186	    ("uma_zfree_smr: called with non-SMR zone."));
4187	KASSERT(item != NULL, ("uma_zfree_smr: Called with NULL pointer."));
4188	SMR_ASSERT_NOT_ENTERED(zone->uz_smr);
4189	if (uma_zfree_debug(zone, item, NULL) == EJUSTRETURN)
4190		return;
4191#endif
4192	cache = &zone->uz_cpu[curcpu];
4193	uz_flags = cache_uz_flags(cache);
4194	itemdomain = 0;
4195#ifdef NUMA
4196	if ((uz_flags & UMA_ZONE_FIRSTTOUCH) != 0)
4197		itemdomain = item_domain(item);
4198#endif
4199	critical_enter();
4200	do {
4201		cache = &zone->uz_cpu[curcpu];
4202		/* SMR Zones must free to the free bucket. */
4203		bucket = &cache->uc_freebucket;
4204#ifdef NUMA
4205		if ((uz_flags & UMA_ZONE_FIRSTTOUCH) != 0 &&
4206		    PCPU_GET(domain) != itemdomain) {
4207			bucket = &cache->uc_crossbucket;
4208		}
4209#endif
4210		if (__predict_true(bucket->ucb_cnt < bucket->ucb_entries)) {
4211			cache_bucket_push(cache, bucket, item);
4212			critical_exit();
4213			return;
4214		}
4215	} while (cache_free(zone, cache, NULL, item, itemdomain));
4216	critical_exit();
4217
4218	/*
4219	 * If nothing else caught this, we'll just do an internal free.
4220	 */
4221	zone_free_item(zone, item, NULL, SKIP_NONE);
4222}
4223
4224/* See uma.h */
4225void
4226uma_zfree_arg(uma_zone_t zone, void *item, void *udata)
4227{
4228	uma_cache_t cache;
4229	uma_cache_bucket_t bucket;
4230	int itemdomain, uz_flags;
4231
4232	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
4233	random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
4234
4235	CTR2(KTR_UMA, "uma_zfree_arg zone %s(%p)", zone->uz_name, zone);
4236
4237#ifdef UMA_ZALLOC_DEBUG
4238	KASSERT((zone->uz_flags & UMA_ZONE_SMR) == 0,
4239	    ("uma_zfree_arg: called with SMR zone."));
4240	if (uma_zfree_debug(zone, item, udata) == EJUSTRETURN)
4241		return;
4242#endif
4243        /* uma_zfree(..., NULL) does nothing, to match free(9). */
4244        if (item == NULL)
4245                return;
4246
4247	/*
4248	 * We are accessing the per-cpu cache without a critical section to
4249	 * fetch size and flags.  This is acceptable, if we are preempted we
4250	 * will simply read another cpu's line.
4251	 */
4252	cache = &zone->uz_cpu[curcpu];
4253	uz_flags = cache_uz_flags(cache);
4254	if (UMA_ALWAYS_CTORDTOR ||
4255	    __predict_false((uz_flags & UMA_ZFLAG_CTORDTOR) != 0))
4256		item_dtor(zone, item, cache_uz_size(cache), udata, SKIP_NONE);
4257
4258	/*
4259	 * The race here is acceptable.  If we miss it we'll just have to wait
4260	 * a little longer for the limits to be reset.
4261	 */
4262	if (__predict_false(uz_flags & UMA_ZFLAG_LIMIT)) {
4263		if (atomic_load_32(&zone->uz_sleepers) > 0)
4264			goto zfree_item;
4265	}
4266
4267	/*
4268	 * If possible, free to the per-CPU cache.  There are two
4269	 * requirements for safe access to the per-CPU cache: (1) the thread
4270	 * accessing the cache must not be preempted or yield during access,
4271	 * and (2) the thread must not migrate CPUs without switching which
4272	 * cache it accesses.  We rely on a critical section to prevent
4273	 * preemption and migration.  We release the critical section in
4274	 * order to acquire the zone mutex if we are unable to free to the
4275	 * current cache; when we re-acquire the critical section, we must
4276	 * detect and handle migration if it has occurred.
4277	 */
4278	itemdomain = 0;
4279#ifdef NUMA
4280	if ((uz_flags & UMA_ZONE_FIRSTTOUCH) != 0)
4281		itemdomain = item_domain(item);
4282#endif
4283	critical_enter();
4284	do {
4285		cache = &zone->uz_cpu[curcpu];
4286		/*
4287		 * Try to free into the allocbucket first to give LIFO
4288		 * ordering for cache-hot datastructures.  Spill over
4289		 * into the freebucket if necessary.  Alloc will swap
4290		 * them if one runs dry.
4291		 */
4292		bucket = &cache->uc_allocbucket;
4293#ifdef NUMA
4294		if ((uz_flags & UMA_ZONE_FIRSTTOUCH) != 0 &&
4295		    PCPU_GET(domain) != itemdomain) {
4296			bucket = &cache->uc_crossbucket;
4297		} else
4298#endif
4299		if (bucket->ucb_cnt == bucket->ucb_entries &&
4300		   cache->uc_freebucket.ucb_cnt <
4301		   cache->uc_freebucket.ucb_entries)
4302			cache_bucket_swap(&cache->uc_freebucket,
4303			    &cache->uc_allocbucket);
4304		if (__predict_true(bucket->ucb_cnt < bucket->ucb_entries)) {
4305			cache_bucket_push(cache, bucket, item);
4306			critical_exit();
4307			return;
4308		}
4309	} while (cache_free(zone, cache, udata, item, itemdomain));
4310	critical_exit();
4311
4312	/*
4313	 * If nothing else caught this, we'll just do an internal free.
4314	 */
4315zfree_item:
4316	zone_free_item(zone, item, udata, SKIP_DTOR);
4317}
4318
4319#ifdef NUMA
4320/*
4321 * sort crossdomain free buckets to domain correct buckets and cache
4322 * them.
4323 */
4324static void
4325zone_free_cross(uma_zone_t zone, uma_bucket_t bucket, void *udata)
4326{
4327	struct uma_bucketlist emptybuckets, fullbuckets;
4328	uma_zone_domain_t zdom;
4329	uma_bucket_t b;
4330	smr_seq_t seq;
4331	void *item;
4332	int domain;
4333
4334	CTR3(KTR_UMA,
4335	    "uma_zfree: zone %s(%p) draining cross bucket %p",
4336	    zone->uz_name, zone, bucket);
4337
4338	/*
4339	 * It is possible for buckets to arrive here out of order so we fetch
4340	 * the current smr seq rather than accepting the bucket's.
4341	 */
4342	seq = SMR_SEQ_INVALID;
4343	if ((zone->uz_flags & UMA_ZONE_SMR) != 0)
4344		seq = smr_advance(zone->uz_smr);
4345
4346	/*
4347	 * To avoid having ndomain * ndomain buckets for sorting we have a
4348	 * lock on the current crossfree bucket.  A full matrix with
4349	 * per-domain locking could be used if necessary.
4350	 */
4351	STAILQ_INIT(&emptybuckets);
4352	STAILQ_INIT(&fullbuckets);
4353	ZONE_CROSS_LOCK(zone);
4354	for (; bucket->ub_cnt > 0; bucket->ub_cnt--) {
4355		item = bucket->ub_bucket[bucket->ub_cnt - 1];
4356		domain = item_domain(item);
4357		zdom = ZDOM_GET(zone, domain);
4358		if (zdom->uzd_cross == NULL) {
4359			if ((b = STAILQ_FIRST(&emptybuckets)) != NULL) {
4360				STAILQ_REMOVE_HEAD(&emptybuckets, ub_link);
4361				zdom->uzd_cross = b;
4362			} else {
4363				/*
4364				 * Avoid allocating a bucket with the cross lock
4365				 * held, since allocation can trigger a
4366				 * cross-domain free and bucket zones may
4367				 * allocate from each other.
4368				 */
4369				ZONE_CROSS_UNLOCK(zone);
4370				b = bucket_alloc(zone, udata, M_NOWAIT);
4371				if (b == NULL)
4372					goto out;
4373				ZONE_CROSS_LOCK(zone);
4374				if (zdom->uzd_cross != NULL) {
4375					STAILQ_INSERT_HEAD(&emptybuckets, b,
4376					    ub_link);
4377				} else {
4378					zdom->uzd_cross = b;
4379				}
4380			}
4381		}
4382		b = zdom->uzd_cross;
4383		b->ub_bucket[b->ub_cnt++] = item;
4384		b->ub_seq = seq;
4385		if (b->ub_cnt == b->ub_entries) {
4386			STAILQ_INSERT_HEAD(&fullbuckets, b, ub_link);
4387			if ((b = STAILQ_FIRST(&emptybuckets)) != NULL)
4388				STAILQ_REMOVE_HEAD(&emptybuckets, ub_link);
4389			zdom->uzd_cross = b;
4390		}
4391	}
4392	ZONE_CROSS_UNLOCK(zone);
4393out:
4394	if (bucket->ub_cnt == 0)
4395		bucket->ub_seq = SMR_SEQ_INVALID;
4396	bucket_free(zone, bucket, udata);
4397
4398	while ((b = STAILQ_FIRST(&emptybuckets)) != NULL) {
4399		STAILQ_REMOVE_HEAD(&emptybuckets, ub_link);
4400		bucket_free(zone, b, udata);
4401	}
4402	while ((b = STAILQ_FIRST(&fullbuckets)) != NULL) {
4403		STAILQ_REMOVE_HEAD(&fullbuckets, ub_link);
4404		domain = item_domain(b->ub_bucket[0]);
4405		zone_put_bucket(zone, domain, b, udata, true);
4406	}
4407}
4408#endif
4409
4410static void
4411zone_free_bucket(uma_zone_t zone, uma_bucket_t bucket, void *udata,
4412    int itemdomain, bool ws)
4413{
4414
4415#ifdef NUMA
4416	/*
4417	 * Buckets coming from the wrong domain will be entirely for the
4418	 * only other domain on two domain systems.  In this case we can
4419	 * simply cache them.  Otherwise we need to sort them back to
4420	 * correct domains.
4421	 */
4422	if ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) != 0 &&
4423	    vm_ndomains > 2 && PCPU_GET(domain) != itemdomain) {
4424		zone_free_cross(zone, bucket, udata);
4425		return;
4426	}
4427#endif
4428
4429	/*
4430	 * Attempt to save the bucket in the zone's domain bucket cache.
4431	 */
4432	CTR3(KTR_UMA,
4433	    "uma_zfree: zone %s(%p) putting bucket %p on free list",
4434	    zone->uz_name, zone, bucket);
4435	/* ub_cnt is pointing to the last free item */
4436	if ((zone->uz_flags & UMA_ZONE_ROUNDROBIN) != 0)
4437		itemdomain = zone_domain_lowest(zone, itemdomain);
4438	zone_put_bucket(zone, itemdomain, bucket, udata, ws);
4439}
4440
4441/*
4442 * Populate a free or cross bucket for the current cpu cache.  Free any
4443 * existing full bucket either to the zone cache or back to the slab layer.
4444 *
4445 * Enters and returns in a critical section.  false return indicates that
4446 * we can not satisfy this free in the cache layer.  true indicates that
4447 * the caller should retry.
4448 */
4449static __noinline bool
4450cache_free(uma_zone_t zone, uma_cache_t cache, void *udata, void *item,
4451    int itemdomain)
4452{
4453	uma_cache_bucket_t cbucket;
4454	uma_bucket_t newbucket, bucket;
4455
4456	CRITICAL_ASSERT(curthread);
4457
4458	if (zone->uz_bucket_size == 0)
4459		return false;
4460
4461	cache = &zone->uz_cpu[curcpu];
4462	newbucket = NULL;
4463
4464	/*
4465	 * FIRSTTOUCH domains need to free to the correct zdom.  When
4466	 * enabled this is the zdom of the item.   The bucket is the
4467	 * cross bucket if the current domain and itemdomain do not match.
4468	 */
4469	cbucket = &cache->uc_freebucket;
4470#ifdef NUMA
4471	if ((cache_uz_flags(cache) & UMA_ZONE_FIRSTTOUCH) != 0) {
4472		if (PCPU_GET(domain) != itemdomain) {
4473			cbucket = &cache->uc_crossbucket;
4474			if (cbucket->ucb_cnt != 0)
4475				counter_u64_add(zone->uz_xdomain,
4476				    cbucket->ucb_cnt);
4477		}
4478	}
4479#endif
4480	bucket = cache_bucket_unload(cbucket);
4481	KASSERT(bucket == NULL || bucket->ub_cnt == bucket->ub_entries,
4482	    ("cache_free: Entered with non-full free bucket."));
4483
4484	/* We are no longer associated with this CPU. */
4485	critical_exit();
4486
4487	/*
4488	 * Don't let SMR zones operate without a free bucket.  Force
4489	 * a synchronize and re-use this one.  We will only degrade
4490	 * to a synchronize every bucket_size items rather than every
4491	 * item if we fail to allocate a bucket.
4492	 */
4493	if ((zone->uz_flags & UMA_ZONE_SMR) != 0) {
4494		if (bucket != NULL)
4495			bucket->ub_seq = smr_advance(zone->uz_smr);
4496		newbucket = bucket_alloc(zone, udata, M_NOWAIT);
4497		if (newbucket == NULL && bucket != NULL) {
4498			bucket_drain(zone, bucket);
4499			newbucket = bucket;
4500			bucket = NULL;
4501		}
4502	} else if (!bucketdisable)
4503		newbucket = bucket_alloc(zone, udata, M_NOWAIT);
4504
4505	if (bucket != NULL)
4506		zone_free_bucket(zone, bucket, udata, itemdomain, true);
4507
4508	critical_enter();
4509	if ((bucket = newbucket) == NULL)
4510		return (false);
4511	cache = &zone->uz_cpu[curcpu];
4512#ifdef NUMA
4513	/*
4514	 * Check to see if we should be populating the cross bucket.  If it
4515	 * is already populated we will fall through and attempt to populate
4516	 * the free bucket.
4517	 */
4518	if ((cache_uz_flags(cache) & UMA_ZONE_FIRSTTOUCH) != 0) {
4519		if (PCPU_GET(domain) != itemdomain &&
4520		    cache->uc_crossbucket.ucb_bucket == NULL) {
4521			cache_bucket_load_cross(cache, bucket);
4522			return (true);
4523		}
4524	}
4525#endif
4526	/*
4527	 * We may have lost the race to fill the bucket or switched CPUs.
4528	 */
4529	if (cache->uc_freebucket.ucb_bucket != NULL) {
4530		critical_exit();
4531		bucket_free(zone, bucket, udata);
4532		critical_enter();
4533	} else
4534		cache_bucket_load_free(cache, bucket);
4535
4536	return (true);
4537}
4538
4539static void
4540slab_free_item(uma_zone_t zone, uma_slab_t slab, void *item)
4541{
4542	uma_keg_t keg;
4543	uma_domain_t dom;
4544	int freei;
4545
4546	keg = zone->uz_keg;
4547	KEG_LOCK_ASSERT(keg, slab->us_domain);
4548
4549	/* Do we need to remove from any lists? */
4550	dom = &keg->uk_domain[slab->us_domain];
4551	if (slab->us_freecount + 1 == keg->uk_ipers) {
4552		LIST_REMOVE(slab, us_link);
4553		LIST_INSERT_HEAD(&dom->ud_free_slab, slab, us_link);
4554		dom->ud_free_slabs++;
4555	} else if (slab->us_freecount == 0) {
4556		LIST_REMOVE(slab, us_link);
4557		LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
4558	}
4559
4560	/* Slab management. */
4561	freei = slab_item_index(slab, keg, item);
4562	BIT_SET(keg->uk_ipers, freei, &slab->us_free);
4563	slab->us_freecount++;
4564
4565	/* Keg statistics. */
4566	dom->ud_free_items++;
4567}
4568
4569static void
4570zone_release(void *arg, void **bucket, int cnt)
4571{
4572	struct mtx *lock;
4573	uma_zone_t zone;
4574	uma_slab_t slab;
4575	uma_keg_t keg;
4576	uint8_t *mem;
4577	void *item;
4578	int i;
4579
4580	zone = arg;
4581	keg = zone->uz_keg;
4582	lock = NULL;
4583	if (__predict_false((zone->uz_flags & UMA_ZFLAG_HASH) != 0))
4584		lock = KEG_LOCK(keg, 0);
4585	for (i = 0; i < cnt; i++) {
4586		item = bucket[i];
4587		if (__predict_true((zone->uz_flags & UMA_ZFLAG_VTOSLAB) != 0)) {
4588			slab = vtoslab((vm_offset_t)item);
4589		} else {
4590			mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
4591			if ((zone->uz_flags & UMA_ZFLAG_HASH) != 0)
4592				slab = hash_sfind(&keg->uk_hash, mem);
4593			else
4594				slab = (uma_slab_t)(mem + keg->uk_pgoff);
4595		}
4596		if (lock != KEG_LOCKPTR(keg, slab->us_domain)) {
4597			if (lock != NULL)
4598				mtx_unlock(lock);
4599			lock = KEG_LOCK(keg, slab->us_domain);
4600		}
4601		slab_free_item(zone, slab, item);
4602	}
4603	if (lock != NULL)
4604		mtx_unlock(lock);
4605}
4606
4607/*
4608 * Frees a single item to any zone.
4609 *
4610 * Arguments:
4611 *	zone   The zone to free to
4612 *	item   The item we're freeing
4613 *	udata  User supplied data for the dtor
4614 *	skip   Skip dtors and finis
4615 */
4616static __noinline void
4617zone_free_item(uma_zone_t zone, void *item, void *udata, enum zfreeskip skip)
4618{
4619
4620	/*
4621	 * If a free is sent directly to an SMR zone we have to
4622	 * synchronize immediately because the item can instantly
4623	 * be reallocated. This should only happen in degenerate
4624	 * cases when no memory is available for per-cpu caches.
4625	 */
4626	if ((zone->uz_flags & UMA_ZONE_SMR) != 0 && skip == SKIP_NONE)
4627		smr_synchronize(zone->uz_smr);
4628
4629	item_dtor(zone, item, zone->uz_size, udata, skip);
4630
4631	if (skip < SKIP_FINI && zone->uz_fini)
4632		zone->uz_fini(item, zone->uz_size);
4633
4634	zone->uz_release(zone->uz_arg, &item, 1);
4635
4636	if (skip & SKIP_CNT)
4637		return;
4638
4639	counter_u64_add(zone->uz_frees, 1);
4640
4641	if (zone->uz_max_items > 0)
4642		zone_free_limit(zone, 1);
4643}
4644
4645/* See uma.h */
4646int
4647uma_zone_set_max(uma_zone_t zone, int nitems)
4648{
4649
4650	/*
4651	 * If the limit is small, we may need to constrain the maximum per-CPU
4652	 * cache size, or disable caching entirely.
4653	 */
4654	uma_zone_set_maxcache(zone, nitems);
4655
4656	/*
4657	 * XXX This can misbehave if the zone has any allocations with
4658	 * no limit and a limit is imposed.  There is currently no
4659	 * way to clear a limit.
4660	 */
4661	ZONE_LOCK(zone);
4662	zone->uz_max_items = nitems;
4663	zone->uz_flags |= UMA_ZFLAG_LIMIT;
4664	zone_update_caches(zone);
4665	/* We may need to wake waiters. */
4666	wakeup(&zone->uz_max_items);
4667	ZONE_UNLOCK(zone);
4668
4669	return (nitems);
4670}
4671
4672/* See uma.h */
4673void
4674uma_zone_set_maxcache(uma_zone_t zone, int nitems)
4675{
4676	int bpcpu, bpdom, bsize, nb;
4677
4678	ZONE_LOCK(zone);
4679
4680	/*
4681	 * Compute a lower bound on the number of items that may be cached in
4682	 * the zone.  Each CPU gets at least two buckets, and for cross-domain
4683	 * frees we use an additional bucket per CPU and per domain.  Select the
4684	 * largest bucket size that does not exceed half of the requested limit,
4685	 * with the left over space given to the full bucket cache.
4686	 */
4687	bpdom = 0;
4688	bpcpu = 2;
4689#ifdef NUMA
4690	if ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) != 0 && vm_ndomains > 1) {
4691		bpcpu++;
4692		bpdom++;
4693	}
4694#endif
4695	nb = bpcpu * mp_ncpus + bpdom * vm_ndomains;
4696	bsize = nitems / nb / 2;
4697	if (bsize > BUCKET_MAX)
4698		bsize = BUCKET_MAX;
4699	else if (bsize == 0 && nitems / nb > 0)
4700		bsize = 1;
4701	zone->uz_bucket_size_max = zone->uz_bucket_size = bsize;
4702	if (zone->uz_bucket_size_min > zone->uz_bucket_size_max)
4703		zone->uz_bucket_size_min = zone->uz_bucket_size_max;
4704	zone->uz_bucket_max = nitems - nb * bsize;
4705	ZONE_UNLOCK(zone);
4706}
4707
4708/* See uma.h */
4709int
4710uma_zone_get_max(uma_zone_t zone)
4711{
4712	int nitems;
4713
4714	nitems = atomic_load_64(&zone->uz_max_items);
4715
4716	return (nitems);
4717}
4718
4719/* See uma.h */
4720void
4721uma_zone_set_warning(uma_zone_t zone, const char *warning)
4722{
4723
4724	ZONE_ASSERT_COLD(zone);
4725	zone->uz_warning = warning;
4726}
4727
4728/* See uma.h */
4729void
4730uma_zone_set_maxaction(uma_zone_t zone, uma_maxaction_t maxaction)
4731{
4732
4733	ZONE_ASSERT_COLD(zone);
4734	TASK_INIT(&zone->uz_maxaction, 0, (task_fn_t *)maxaction, zone);
4735}
4736
4737/* See uma.h */
4738int
4739uma_zone_get_cur(uma_zone_t zone)
4740{
4741	int64_t nitems;
4742	u_int i;
4743
4744	nitems = 0;
4745	if (zone->uz_allocs != EARLY_COUNTER && zone->uz_frees != EARLY_COUNTER)
4746		nitems = counter_u64_fetch(zone->uz_allocs) -
4747		    counter_u64_fetch(zone->uz_frees);
4748	CPU_FOREACH(i)
4749		nitems += atomic_load_64(&zone->uz_cpu[i].uc_allocs) -
4750		    atomic_load_64(&zone->uz_cpu[i].uc_frees);
4751
4752	return (nitems < 0 ? 0 : nitems);
4753}
4754
4755static uint64_t
4756uma_zone_get_allocs(uma_zone_t zone)
4757{
4758	uint64_t nitems;
4759	u_int i;
4760
4761	nitems = 0;
4762	if (zone->uz_allocs != EARLY_COUNTER)
4763		nitems = counter_u64_fetch(zone->uz_allocs);
4764	CPU_FOREACH(i)
4765		nitems += atomic_load_64(&zone->uz_cpu[i].uc_allocs);
4766
4767	return (nitems);
4768}
4769
4770static uint64_t
4771uma_zone_get_frees(uma_zone_t zone)
4772{
4773	uint64_t nitems;
4774	u_int i;
4775
4776	nitems = 0;
4777	if (zone->uz_frees != EARLY_COUNTER)
4778		nitems = counter_u64_fetch(zone->uz_frees);
4779	CPU_FOREACH(i)
4780		nitems += atomic_load_64(&zone->uz_cpu[i].uc_frees);
4781
4782	return (nitems);
4783}
4784
4785#ifdef INVARIANTS
4786/* Used only for KEG_ASSERT_COLD(). */
4787static uint64_t
4788uma_keg_get_allocs(uma_keg_t keg)
4789{
4790	uma_zone_t z;
4791	uint64_t nitems;
4792
4793	nitems = 0;
4794	LIST_FOREACH(z, &keg->uk_zones, uz_link)
4795		nitems += uma_zone_get_allocs(z);
4796
4797	return (nitems);
4798}
4799#endif
4800
4801/* See uma.h */
4802void
4803uma_zone_set_init(uma_zone_t zone, uma_init uminit)
4804{
4805	uma_keg_t keg;
4806
4807	KEG_GET(zone, keg);
4808	KEG_ASSERT_COLD(keg);
4809	keg->uk_init = uminit;
4810}
4811
4812/* See uma.h */
4813void
4814uma_zone_set_fini(uma_zone_t zone, uma_fini fini)
4815{
4816	uma_keg_t keg;
4817
4818	KEG_GET(zone, keg);
4819	KEG_ASSERT_COLD(keg);
4820	keg->uk_fini = fini;
4821}
4822
4823/* See uma.h */
4824void
4825uma_zone_set_zinit(uma_zone_t zone, uma_init zinit)
4826{
4827
4828	ZONE_ASSERT_COLD(zone);
4829	zone->uz_init = zinit;
4830}
4831
4832/* See uma.h */
4833void
4834uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini)
4835{
4836
4837	ZONE_ASSERT_COLD(zone);
4838	zone->uz_fini = zfini;
4839}
4840
4841/* See uma.h */
4842void
4843uma_zone_set_freef(uma_zone_t zone, uma_free freef)
4844{
4845	uma_keg_t keg;
4846
4847	KEG_GET(zone, keg);
4848	KEG_ASSERT_COLD(keg);
4849	keg->uk_freef = freef;
4850}
4851
4852/* See uma.h */
4853void
4854uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf)
4855{
4856	uma_keg_t keg;
4857
4858	KEG_GET(zone, keg);
4859	KEG_ASSERT_COLD(keg);
4860	keg->uk_allocf = allocf;
4861}
4862
4863/* See uma.h */
4864void
4865uma_zone_set_smr(uma_zone_t zone, smr_t smr)
4866{
4867
4868	ZONE_ASSERT_COLD(zone);
4869
4870	KASSERT(smr != NULL, ("Got NULL smr"));
4871	KASSERT((zone->uz_flags & UMA_ZONE_SMR) == 0,
4872	    ("zone %p (%s) already uses SMR", zone, zone->uz_name));
4873	zone->uz_flags |= UMA_ZONE_SMR;
4874	zone->uz_smr = smr;
4875	zone_update_caches(zone);
4876}
4877
4878smr_t
4879uma_zone_get_smr(uma_zone_t zone)
4880{
4881
4882	return (zone->uz_smr);
4883}
4884
4885/* See uma.h */
4886void
4887uma_zone_reserve(uma_zone_t zone, int items)
4888{
4889	uma_keg_t keg;
4890
4891	KEG_GET(zone, keg);
4892	KEG_ASSERT_COLD(keg);
4893	keg->uk_reserve = items;
4894}
4895
4896/* See uma.h */
4897int
4898uma_zone_reserve_kva(uma_zone_t zone, int count)
4899{
4900	uma_keg_t keg;
4901	vm_offset_t kva;
4902	u_int pages;
4903
4904	KEG_GET(zone, keg);
4905	KEG_ASSERT_COLD(keg);
4906	ZONE_ASSERT_COLD(zone);
4907
4908	pages = howmany(count, keg->uk_ipers) * keg->uk_ppera;
4909
4910#ifdef UMA_MD_SMALL_ALLOC
4911	if (keg->uk_ppera > 1) {
4912#else
4913	if (1) {
4914#endif
4915		kva = kva_alloc((vm_size_t)pages * PAGE_SIZE);
4916		if (kva == 0)
4917			return (0);
4918	} else
4919		kva = 0;
4920
4921	MPASS(keg->uk_kva == 0);
4922	keg->uk_kva = kva;
4923	keg->uk_offset = 0;
4924	zone->uz_max_items = pages * keg->uk_ipers;
4925#ifdef UMA_MD_SMALL_ALLOC
4926	keg->uk_allocf = (keg->uk_ppera > 1) ? noobj_alloc : uma_small_alloc;
4927#else
4928	keg->uk_allocf = noobj_alloc;
4929#endif
4930	keg->uk_flags |= UMA_ZFLAG_LIMIT | UMA_ZONE_NOFREE;
4931	zone->uz_flags |= UMA_ZFLAG_LIMIT | UMA_ZONE_NOFREE;
4932	zone_update_caches(zone);
4933
4934	return (1);
4935}
4936
4937/* See uma.h */
4938void
4939uma_prealloc(uma_zone_t zone, int items)
4940{
4941	struct vm_domainset_iter di;
4942	uma_domain_t dom;
4943	uma_slab_t slab;
4944	uma_keg_t keg;
4945	int aflags, domain, slabs;
4946
4947	KEG_GET(zone, keg);
4948	slabs = howmany(items, keg->uk_ipers);
4949	while (slabs-- > 0) {
4950		aflags = M_NOWAIT;
4951		vm_domainset_iter_policy_ref_init(&di, &keg->uk_dr, &domain,
4952		    &aflags);
4953		for (;;) {
4954			slab = keg_alloc_slab(keg, zone, domain, M_WAITOK,
4955			    aflags);
4956			if (slab != NULL) {
4957				dom = &keg->uk_domain[slab->us_domain];
4958				/*
4959				 * keg_alloc_slab() always returns a slab on the
4960				 * partial list.
4961				 */
4962				LIST_REMOVE(slab, us_link);
4963				LIST_INSERT_HEAD(&dom->ud_free_slab, slab,
4964				    us_link);
4965				dom->ud_free_slabs++;
4966				KEG_UNLOCK(keg, slab->us_domain);
4967				break;
4968			}
4969			if (vm_domainset_iter_policy(&di, &domain) != 0)
4970				vm_wait_doms(&keg->uk_dr.dr_policy->ds_mask, 0);
4971		}
4972	}
4973}
4974
4975/*
4976 * Returns a snapshot of memory consumption in bytes.
4977 */
4978size_t
4979uma_zone_memory(uma_zone_t zone)
4980{
4981	size_t sz;
4982	int i;
4983
4984	sz = 0;
4985	if (zone->uz_flags & UMA_ZFLAG_CACHE) {
4986		for (i = 0; i < vm_ndomains; i++)
4987			sz += ZDOM_GET(zone, i)->uzd_nitems;
4988		return (sz * zone->uz_size);
4989	}
4990	for (i = 0; i < vm_ndomains; i++)
4991		sz += zone->uz_keg->uk_domain[i].ud_pages;
4992
4993	return (sz * PAGE_SIZE);
4994}
4995
4996/* See uma.h */
4997void
4998uma_reclaim(int req)
4999{
5000	uma_reclaim_domain(req, UMA_ANYDOMAIN);
5001}
5002
5003void
5004uma_reclaim_domain(int req, int domain)
5005{
5006	void *arg;
5007
5008	bucket_enable();
5009
5010	arg = (void *)(uintptr_t)domain;
5011	sx_slock(&uma_reclaim_lock);
5012	switch (req) {
5013	case UMA_RECLAIM_TRIM:
5014		zone_foreach(zone_trim, arg);
5015		break;
5016	case UMA_RECLAIM_DRAIN:
5017		zone_foreach(zone_drain, arg);
5018		break;
5019	case UMA_RECLAIM_DRAIN_CPU:
5020		zone_foreach(zone_drain, arg);
5021		pcpu_cache_drain_safe(NULL);
5022		zone_foreach(zone_drain, arg);
5023		break;
5024	default:
5025		panic("unhandled reclamation request %d", req);
5026	}
5027
5028	/*
5029	 * Some slabs may have been freed but this zone will be visited early
5030	 * we visit again so that we can free pages that are empty once other
5031	 * zones are drained.  We have to do the same for buckets.
5032	 */
5033	zone_drain(slabzones[0], arg);
5034	zone_drain(slabzones[1], arg);
5035	bucket_zone_drain(domain);
5036	sx_sunlock(&uma_reclaim_lock);
5037}
5038
5039static volatile int uma_reclaim_needed;
5040
5041void
5042uma_reclaim_wakeup(void)
5043{
5044
5045	if (atomic_fetchadd_int(&uma_reclaim_needed, 1) == 0)
5046		wakeup(uma_reclaim);
5047}
5048
5049void
5050uma_reclaim_worker(void *arg __unused)
5051{
5052
5053	for (;;) {
5054		sx_xlock(&uma_reclaim_lock);
5055		while (atomic_load_int(&uma_reclaim_needed) == 0)
5056			sx_sleep(uma_reclaim, &uma_reclaim_lock, PVM, "umarcl",
5057			    hz);
5058		sx_xunlock(&uma_reclaim_lock);
5059		EVENTHANDLER_INVOKE(vm_lowmem, VM_LOW_KMEM);
5060		uma_reclaim(UMA_RECLAIM_DRAIN_CPU);
5061		atomic_store_int(&uma_reclaim_needed, 0);
5062		/* Don't fire more than once per-second. */
5063		pause("umarclslp", hz);
5064	}
5065}
5066
5067/* See uma.h */
5068void
5069uma_zone_reclaim(uma_zone_t zone, int req)
5070{
5071	uma_zone_reclaim_domain(zone, req, UMA_ANYDOMAIN);
5072}
5073
5074void
5075uma_zone_reclaim_domain(uma_zone_t zone, int req, int domain)
5076{
5077	void *arg;
5078
5079	arg = (void *)(uintptr_t)domain;
5080	switch (req) {
5081	case UMA_RECLAIM_TRIM:
5082		zone_trim(zone, arg);
5083		break;
5084	case UMA_RECLAIM_DRAIN:
5085		zone_drain(zone, arg);
5086		break;
5087	case UMA_RECLAIM_DRAIN_CPU:
5088		pcpu_cache_drain_safe(zone);
5089		zone_drain(zone, arg);
5090		break;
5091	default:
5092		panic("unhandled reclamation request %d", req);
5093	}
5094}
5095
5096/* See uma.h */
5097int
5098uma_zone_exhausted(uma_zone_t zone)
5099{
5100
5101	return (atomic_load_32(&zone->uz_sleepers) > 0);
5102}
5103
5104unsigned long
5105uma_limit(void)
5106{
5107
5108	return (uma_kmem_limit);
5109}
5110
5111void
5112uma_set_limit(unsigned long limit)
5113{
5114
5115	uma_kmem_limit = limit;
5116}
5117
5118unsigned long
5119uma_size(void)
5120{
5121
5122	return (atomic_load_long(&uma_kmem_total));
5123}
5124
5125long
5126uma_avail(void)
5127{
5128
5129	return (uma_kmem_limit - uma_size());
5130}
5131
5132#ifdef DDB
5133/*
5134 * Generate statistics across both the zone and its per-cpu cache's.  Return
5135 * desired statistics if the pointer is non-NULL for that statistic.
5136 *
5137 * Note: does not update the zone statistics, as it can't safely clear the
5138 * per-CPU cache statistic.
5139 *
5140 */
5141static void
5142uma_zone_sumstat(uma_zone_t z, long *cachefreep, uint64_t *allocsp,
5143    uint64_t *freesp, uint64_t *sleepsp, uint64_t *xdomainp)
5144{
5145	uma_cache_t cache;
5146	uint64_t allocs, frees, sleeps, xdomain;
5147	int cachefree, cpu;
5148
5149	allocs = frees = sleeps = xdomain = 0;
5150	cachefree = 0;
5151	CPU_FOREACH(cpu) {
5152		cache = &z->uz_cpu[cpu];
5153		cachefree += cache->uc_allocbucket.ucb_cnt;
5154		cachefree += cache->uc_freebucket.ucb_cnt;
5155		xdomain += cache->uc_crossbucket.ucb_cnt;
5156		cachefree += cache->uc_crossbucket.ucb_cnt;
5157		allocs += cache->uc_allocs;
5158		frees += cache->uc_frees;
5159	}
5160	allocs += counter_u64_fetch(z->uz_allocs);
5161	frees += counter_u64_fetch(z->uz_frees);
5162	xdomain += counter_u64_fetch(z->uz_xdomain);
5163	sleeps += z->uz_sleeps;
5164	if (cachefreep != NULL)
5165		*cachefreep = cachefree;
5166	if (allocsp != NULL)
5167		*allocsp = allocs;
5168	if (freesp != NULL)
5169		*freesp = frees;
5170	if (sleepsp != NULL)
5171		*sleepsp = sleeps;
5172	if (xdomainp != NULL)
5173		*xdomainp = xdomain;
5174}
5175#endif /* DDB */
5176
5177static int
5178sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS)
5179{
5180	uma_keg_t kz;
5181	uma_zone_t z;
5182	int count;
5183
5184	count = 0;
5185	rw_rlock(&uma_rwlock);
5186	LIST_FOREACH(kz, &uma_kegs, uk_link) {
5187		LIST_FOREACH(z, &kz->uk_zones, uz_link)
5188			count++;
5189	}
5190	LIST_FOREACH(z, &uma_cachezones, uz_link)
5191		count++;
5192
5193	rw_runlock(&uma_rwlock);
5194	return (sysctl_handle_int(oidp, &count, 0, req));
5195}
5196
5197static void
5198uma_vm_zone_stats(struct uma_type_header *uth, uma_zone_t z, struct sbuf *sbuf,
5199    struct uma_percpu_stat *ups, bool internal)
5200{
5201	uma_zone_domain_t zdom;
5202	uma_cache_t cache;
5203	int i;
5204
5205	for (i = 0; i < vm_ndomains; i++) {
5206		zdom = ZDOM_GET(z, i);
5207		uth->uth_zone_free += zdom->uzd_nitems;
5208	}
5209	uth->uth_allocs = counter_u64_fetch(z->uz_allocs);
5210	uth->uth_frees = counter_u64_fetch(z->uz_frees);
5211	uth->uth_fails = counter_u64_fetch(z->uz_fails);
5212	uth->uth_xdomain = counter_u64_fetch(z->uz_xdomain);
5213	uth->uth_sleeps = z->uz_sleeps;
5214
5215	for (i = 0; i < mp_maxid + 1; i++) {
5216		bzero(&ups[i], sizeof(*ups));
5217		if (internal || CPU_ABSENT(i))
5218			continue;
5219		cache = &z->uz_cpu[i];
5220		ups[i].ups_cache_free += cache->uc_allocbucket.ucb_cnt;
5221		ups[i].ups_cache_free += cache->uc_freebucket.ucb_cnt;
5222		ups[i].ups_cache_free += cache->uc_crossbucket.ucb_cnt;
5223		ups[i].ups_allocs = cache->uc_allocs;
5224		ups[i].ups_frees = cache->uc_frees;
5225	}
5226}
5227
5228static int
5229sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS)
5230{
5231	struct uma_stream_header ush;
5232	struct uma_type_header uth;
5233	struct uma_percpu_stat *ups;
5234	struct sbuf sbuf;
5235	uma_keg_t kz;
5236	uma_zone_t z;
5237	uint64_t items;
5238	uint32_t kfree, pages;
5239	int count, error, i;
5240
5241	error = sysctl_wire_old_buffer(req, 0);
5242	if (error != 0)
5243		return (error);
5244	sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
5245	sbuf_clear_flags(&sbuf, SBUF_INCLUDENUL);
5246	ups = malloc((mp_maxid + 1) * sizeof(*ups), M_TEMP, M_WAITOK);
5247
5248	count = 0;
5249	rw_rlock(&uma_rwlock);
5250	LIST_FOREACH(kz, &uma_kegs, uk_link) {
5251		LIST_FOREACH(z, &kz->uk_zones, uz_link)
5252			count++;
5253	}
5254
5255	LIST_FOREACH(z, &uma_cachezones, uz_link)
5256		count++;
5257
5258	/*
5259	 * Insert stream header.
5260	 */
5261	bzero(&ush, sizeof(ush));
5262	ush.ush_version = UMA_STREAM_VERSION;
5263	ush.ush_maxcpus = (mp_maxid + 1);
5264	ush.ush_count = count;
5265	(void)sbuf_bcat(&sbuf, &ush, sizeof(ush));
5266
5267	LIST_FOREACH(kz, &uma_kegs, uk_link) {
5268		kfree = pages = 0;
5269		for (i = 0; i < vm_ndomains; i++) {
5270			kfree += kz->uk_domain[i].ud_free_items;
5271			pages += kz->uk_domain[i].ud_pages;
5272		}
5273		LIST_FOREACH(z, &kz->uk_zones, uz_link) {
5274			bzero(&uth, sizeof(uth));
5275			strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
5276			uth.uth_align = kz->uk_align;
5277			uth.uth_size = kz->uk_size;
5278			uth.uth_rsize = kz->uk_rsize;
5279			if (z->uz_max_items > 0) {
5280				items = UZ_ITEMS_COUNT(z->uz_items);
5281				uth.uth_pages = (items / kz->uk_ipers) *
5282					kz->uk_ppera;
5283			} else
5284				uth.uth_pages = pages;
5285			uth.uth_maxpages = (z->uz_max_items / kz->uk_ipers) *
5286			    kz->uk_ppera;
5287			uth.uth_limit = z->uz_max_items;
5288			uth.uth_keg_free = kfree;
5289
5290			/*
5291			 * A zone is secondary is it is not the first entry
5292			 * on the keg's zone list.
5293			 */
5294			if ((z->uz_flags & UMA_ZONE_SECONDARY) &&
5295			    (LIST_FIRST(&kz->uk_zones) != z))
5296				uth.uth_zone_flags = UTH_ZONE_SECONDARY;
5297			uma_vm_zone_stats(&uth, z, &sbuf, ups,
5298			    kz->uk_flags & UMA_ZFLAG_INTERNAL);
5299			(void)sbuf_bcat(&sbuf, &uth, sizeof(uth));
5300			for (i = 0; i < mp_maxid + 1; i++)
5301				(void)sbuf_bcat(&sbuf, &ups[i], sizeof(ups[i]));
5302		}
5303	}
5304	LIST_FOREACH(z, &uma_cachezones, uz_link) {
5305		bzero(&uth, sizeof(uth));
5306		strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
5307		uth.uth_size = z->uz_size;
5308		uma_vm_zone_stats(&uth, z, &sbuf, ups, false);
5309		(void)sbuf_bcat(&sbuf, &uth, sizeof(uth));
5310		for (i = 0; i < mp_maxid + 1; i++)
5311			(void)sbuf_bcat(&sbuf, &ups[i], sizeof(ups[i]));
5312	}
5313
5314	rw_runlock(&uma_rwlock);
5315	error = sbuf_finish(&sbuf);
5316	sbuf_delete(&sbuf);
5317	free(ups, M_TEMP);
5318	return (error);
5319}
5320
5321int
5322sysctl_handle_uma_zone_max(SYSCTL_HANDLER_ARGS)
5323{
5324	uma_zone_t zone = *(uma_zone_t *)arg1;
5325	int error, max;
5326
5327	max = uma_zone_get_max(zone);
5328	error = sysctl_handle_int(oidp, &max, 0, req);
5329	if (error || !req->newptr)
5330		return (error);
5331
5332	uma_zone_set_max(zone, max);
5333
5334	return (0);
5335}
5336
5337int
5338sysctl_handle_uma_zone_cur(SYSCTL_HANDLER_ARGS)
5339{
5340	uma_zone_t zone;
5341	int cur;
5342
5343	/*
5344	 * Some callers want to add sysctls for global zones that
5345	 * may not yet exist so they pass a pointer to a pointer.
5346	 */
5347	if (arg2 == 0)
5348		zone = *(uma_zone_t *)arg1;
5349	else
5350		zone = arg1;
5351	cur = uma_zone_get_cur(zone);
5352	return (sysctl_handle_int(oidp, &cur, 0, req));
5353}
5354
5355static int
5356sysctl_handle_uma_zone_allocs(SYSCTL_HANDLER_ARGS)
5357{
5358	uma_zone_t zone = arg1;
5359	uint64_t cur;
5360
5361	cur = uma_zone_get_allocs(zone);
5362	return (sysctl_handle_64(oidp, &cur, 0, req));
5363}
5364
5365static int
5366sysctl_handle_uma_zone_frees(SYSCTL_HANDLER_ARGS)
5367{
5368	uma_zone_t zone = arg1;
5369	uint64_t cur;
5370
5371	cur = uma_zone_get_frees(zone);
5372	return (sysctl_handle_64(oidp, &cur, 0, req));
5373}
5374
5375static int
5376sysctl_handle_uma_zone_flags(SYSCTL_HANDLER_ARGS)
5377{
5378	struct sbuf sbuf;
5379	uma_zone_t zone = arg1;
5380	int error;
5381
5382	sbuf_new_for_sysctl(&sbuf, NULL, 0, req);
5383	if (zone->uz_flags != 0)
5384		sbuf_printf(&sbuf, "0x%b", zone->uz_flags, PRINT_UMA_ZFLAGS);
5385	else
5386		sbuf_printf(&sbuf, "0");
5387	error = sbuf_finish(&sbuf);
5388	sbuf_delete(&sbuf);
5389
5390	return (error);
5391}
5392
5393static int
5394sysctl_handle_uma_slab_efficiency(SYSCTL_HANDLER_ARGS)
5395{
5396	uma_keg_t keg = arg1;
5397	int avail, effpct, total;
5398
5399	total = keg->uk_ppera * PAGE_SIZE;
5400	if ((keg->uk_flags & UMA_ZFLAG_OFFPAGE) != 0)
5401		total += slabzone(keg->uk_ipers)->uz_keg->uk_rsize;
5402	/*
5403	 * We consider the client's requested size and alignment here, not the
5404	 * real size determination uk_rsize, because we also adjust the real
5405	 * size for internal implementation reasons (max bitset size).
5406	 */
5407	avail = keg->uk_ipers * roundup2(keg->uk_size, keg->uk_align + 1);
5408	if ((keg->uk_flags & UMA_ZONE_PCPU) != 0)
5409		avail *= mp_maxid + 1;
5410	effpct = 100 * avail / total;
5411	return (sysctl_handle_int(oidp, &effpct, 0, req));
5412}
5413
5414static int
5415sysctl_handle_uma_zone_items(SYSCTL_HANDLER_ARGS)
5416{
5417	uma_zone_t zone = arg1;
5418	uint64_t cur;
5419
5420	cur = UZ_ITEMS_COUNT(atomic_load_64(&zone->uz_items));
5421	return (sysctl_handle_64(oidp, &cur, 0, req));
5422}
5423
5424#ifdef INVARIANTS
5425static uma_slab_t
5426uma_dbg_getslab(uma_zone_t zone, void *item)
5427{
5428	uma_slab_t slab;
5429	uma_keg_t keg;
5430	uint8_t *mem;
5431
5432	/*
5433	 * It is safe to return the slab here even though the
5434	 * zone is unlocked because the item's allocation state
5435	 * essentially holds a reference.
5436	 */
5437	mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
5438	if ((zone->uz_flags & UMA_ZFLAG_CACHE) != 0)
5439		return (NULL);
5440	if (zone->uz_flags & UMA_ZFLAG_VTOSLAB)
5441		return (vtoslab((vm_offset_t)mem));
5442	keg = zone->uz_keg;
5443	if ((keg->uk_flags & UMA_ZFLAG_HASH) == 0)
5444		return ((uma_slab_t)(mem + keg->uk_pgoff));
5445	KEG_LOCK(keg, 0);
5446	slab = hash_sfind(&keg->uk_hash, mem);
5447	KEG_UNLOCK(keg, 0);
5448
5449	return (slab);
5450}
5451
5452static bool
5453uma_dbg_zskip(uma_zone_t zone, void *mem)
5454{
5455
5456	if ((zone->uz_flags & UMA_ZFLAG_CACHE) != 0)
5457		return (true);
5458
5459	return (uma_dbg_kskip(zone->uz_keg, mem));
5460}
5461
5462static bool
5463uma_dbg_kskip(uma_keg_t keg, void *mem)
5464{
5465	uintptr_t idx;
5466
5467	if (dbg_divisor == 0)
5468		return (true);
5469
5470	if (dbg_divisor == 1)
5471		return (false);
5472
5473	idx = (uintptr_t)mem >> PAGE_SHIFT;
5474	if (keg->uk_ipers > 1) {
5475		idx *= keg->uk_ipers;
5476		idx += ((uintptr_t)mem & PAGE_MASK) / keg->uk_rsize;
5477	}
5478
5479	if ((idx / dbg_divisor) * dbg_divisor != idx) {
5480		counter_u64_add(uma_skip_cnt, 1);
5481		return (true);
5482	}
5483	counter_u64_add(uma_dbg_cnt, 1);
5484
5485	return (false);
5486}
5487
5488/*
5489 * Set up the slab's freei data such that uma_dbg_free can function.
5490 *
5491 */
5492static void
5493uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item)
5494{
5495	uma_keg_t keg;
5496	int freei;
5497
5498	if (slab == NULL) {
5499		slab = uma_dbg_getslab(zone, item);
5500		if (slab == NULL)
5501			panic("uma: item %p did not belong to zone %s",
5502			    item, zone->uz_name);
5503	}
5504	keg = zone->uz_keg;
5505	freei = slab_item_index(slab, keg, item);
5506
5507	if (BIT_TEST_SET_ATOMIC(keg->uk_ipers, freei,
5508	    slab_dbg_bits(slab, keg)))
5509		panic("Duplicate alloc of %p from zone %p(%s) slab %p(%d)",
5510		    item, zone, zone->uz_name, slab, freei);
5511}
5512
5513/*
5514 * Verifies freed addresses.  Checks for alignment, valid slab membership
5515 * and duplicate frees.
5516 *
5517 */
5518static void
5519uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item)
5520{
5521	uma_keg_t keg;
5522	int freei;
5523
5524	if (slab == NULL) {
5525		slab = uma_dbg_getslab(zone, item);
5526		if (slab == NULL)
5527			panic("uma: Freed item %p did not belong to zone %s",
5528			    item, zone->uz_name);
5529	}
5530	keg = zone->uz_keg;
5531	freei = slab_item_index(slab, keg, item);
5532
5533	if (freei >= keg->uk_ipers)
5534		panic("Invalid free of %p from zone %p(%s) slab %p(%d)",
5535		    item, zone, zone->uz_name, slab, freei);
5536
5537	if (slab_item(slab, keg, freei) != item)
5538		panic("Unaligned free of %p from zone %p(%s) slab %p(%d)",
5539		    item, zone, zone->uz_name, slab, freei);
5540
5541	if (!BIT_TEST_CLR_ATOMIC(keg->uk_ipers, freei,
5542	    slab_dbg_bits(slab, keg)))
5543		panic("Duplicate free of %p from zone %p(%s) slab %p(%d)",
5544		    item, zone, zone->uz_name, slab, freei);
5545}
5546#endif /* INVARIANTS */
5547
5548#ifdef DDB
5549static int64_t
5550get_uma_stats(uma_keg_t kz, uma_zone_t z, uint64_t *allocs, uint64_t *used,
5551    uint64_t *sleeps, long *cachefree, uint64_t *xdomain)
5552{
5553	uint64_t frees;
5554	int i;
5555
5556	if (kz->uk_flags & UMA_ZFLAG_INTERNAL) {
5557		*allocs = counter_u64_fetch(z->uz_allocs);
5558		frees = counter_u64_fetch(z->uz_frees);
5559		*sleeps = z->uz_sleeps;
5560		*cachefree = 0;
5561		*xdomain = 0;
5562	} else
5563		uma_zone_sumstat(z, cachefree, allocs, &frees, sleeps,
5564		    xdomain);
5565	for (i = 0; i < vm_ndomains; i++) {
5566		*cachefree += ZDOM_GET(z, i)->uzd_nitems;
5567		if (!((z->uz_flags & UMA_ZONE_SECONDARY) &&
5568		    (LIST_FIRST(&kz->uk_zones) != z)))
5569			*cachefree += kz->uk_domain[i].ud_free_items;
5570	}
5571	*used = *allocs - frees;
5572	return (((int64_t)*used + *cachefree) * kz->uk_size);
5573}
5574
5575DB_SHOW_COMMAND(uma, db_show_uma)
5576{
5577	const char *fmt_hdr, *fmt_entry;
5578	uma_keg_t kz;
5579	uma_zone_t z;
5580	uint64_t allocs, used, sleeps, xdomain;
5581	long cachefree;
5582	/* variables for sorting */
5583	uma_keg_t cur_keg;
5584	uma_zone_t cur_zone, last_zone;
5585	int64_t cur_size, last_size, size;
5586	int ties;
5587
5588	/* /i option produces machine-parseable CSV output */
5589	if (modif[0] == 'i') {
5590		fmt_hdr = "%s,%s,%s,%s,%s,%s,%s,%s,%s\n";
5591		fmt_entry = "\"%s\",%ju,%jd,%ld,%ju,%ju,%u,%jd,%ju\n";
5592	} else {
5593		fmt_hdr = "%18s %6s %7s %7s %11s %7s %7s %10s %8s\n";
5594		fmt_entry = "%18s %6ju %7jd %7ld %11ju %7ju %7u %10jd %8ju\n";
5595	}
5596
5597	db_printf(fmt_hdr, "Zone", "Size", "Used", "Free", "Requests",
5598	    "Sleeps", "Bucket", "Total Mem", "XFree");
5599
5600	/* Sort the zones with largest size first. */
5601	last_zone = NULL;
5602	last_size = INT64_MAX;
5603	for (;;) {
5604		cur_zone = NULL;
5605		cur_size = -1;
5606		ties = 0;
5607		LIST_FOREACH(kz, &uma_kegs, uk_link) {
5608			LIST_FOREACH(z, &kz->uk_zones, uz_link) {
5609				/*
5610				 * In the case of size ties, print out zones
5611				 * in the order they are encountered.  That is,
5612				 * when we encounter the most recently output
5613				 * zone, we have already printed all preceding
5614				 * ties, and we must print all following ties.
5615				 */
5616				if (z == last_zone) {
5617					ties = 1;
5618					continue;
5619				}
5620				size = get_uma_stats(kz, z, &allocs, &used,
5621				    &sleeps, &cachefree, &xdomain);
5622				if (size > cur_size && size < last_size + ties)
5623				{
5624					cur_size = size;
5625					cur_zone = z;
5626					cur_keg = kz;
5627				}
5628			}
5629		}
5630		if (cur_zone == NULL)
5631			break;
5632
5633		size = get_uma_stats(cur_keg, cur_zone, &allocs, &used,
5634		    &sleeps, &cachefree, &xdomain);
5635		db_printf(fmt_entry, cur_zone->uz_name,
5636		    (uintmax_t)cur_keg->uk_size, (intmax_t)used, cachefree,
5637		    (uintmax_t)allocs, (uintmax_t)sleeps,
5638		    (unsigned)cur_zone->uz_bucket_size, (intmax_t)size,
5639		    xdomain);
5640
5641		if (db_pager_quit)
5642			return;
5643		last_zone = cur_zone;
5644		last_size = cur_size;
5645	}
5646}
5647
5648DB_SHOW_COMMAND(umacache, db_show_umacache)
5649{
5650	uma_zone_t z;
5651	uint64_t allocs, frees;
5652	long cachefree;
5653	int i;
5654
5655	db_printf("%18s %8s %8s %8s %12s %8s\n", "Zone", "Size", "Used", "Free",
5656	    "Requests", "Bucket");
5657	LIST_FOREACH(z, &uma_cachezones, uz_link) {
5658		uma_zone_sumstat(z, &cachefree, &allocs, &frees, NULL, NULL);
5659		for (i = 0; i < vm_ndomains; i++)
5660			cachefree += ZDOM_GET(z, i)->uzd_nitems;
5661		db_printf("%18s %8ju %8jd %8ld %12ju %8u\n",
5662		    z->uz_name, (uintmax_t)z->uz_size,
5663		    (intmax_t)(allocs - frees), cachefree,
5664		    (uintmax_t)allocs, z->uz_bucket_size);
5665		if (db_pager_quit)
5666			return;
5667	}
5668}
5669#endif	/* DDB */
5670