xref: /freebsd/sys/vm/uma_core.c (revision 8a0a413e)
1 /*-
2  * Copyright (c) 2002-2005, 2009, 2013 Jeffrey Roberson <jeff@FreeBSD.org>
3  * Copyright (c) 2004, 2005 Bosko Milekic <bmilekic@FreeBSD.org>
4  * Copyright (c) 2004-2006 Robert N. M. Watson
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice unmodified, this list of conditions, and the following
12  *    disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /*
30  * uma_core.c  Implementation of the Universal Memory allocator
31  *
32  * This allocator is intended to replace the multitude of similar object caches
33  * in the standard FreeBSD kernel.  The intent is to be flexible as well as
34  * efficient.  A primary design goal is to return unused memory to the rest of
35  * the system.  This will make the system as a whole more flexible due to the
36  * ability to move memory to subsystems which most need it instead of leaving
37  * pools of reserved memory unused.
38  *
39  * The basic ideas stem from similar slab/zone based allocators whose algorithms
40  * are well known.
41  *
42  */
43 
44 /*
45  * TODO:
46  *	- Improve memory usage for large allocations
47  *	- Investigate cache size adjustments
48  */
49 
50 #include <sys/cdefs.h>
51 __FBSDID("$FreeBSD$");
52 
53 #include "opt_ddb.h"
54 #include "opt_param.h"
55 #include "opt_vm.h"
56 
57 #include <sys/param.h>
58 #include <sys/systm.h>
59 #include <sys/bitset.h>
60 #include <sys/eventhandler.h>
61 #include <sys/kernel.h>
62 #include <sys/types.h>
63 #include <sys/queue.h>
64 #include <sys/malloc.h>
65 #include <sys/ktr.h>
66 #include <sys/lock.h>
67 #include <sys/sysctl.h>
68 #include <sys/mutex.h>
69 #include <sys/proc.h>
70 #include <sys/random.h>
71 #include <sys/rwlock.h>
72 #include <sys/sbuf.h>
73 #include <sys/sched.h>
74 #include <sys/smp.h>
75 #include <sys/taskqueue.h>
76 #include <sys/vmmeter.h>
77 
78 #include <vm/vm.h>
79 #include <vm/vm_object.h>
80 #include <vm/vm_page.h>
81 #include <vm/vm_pageout.h>
82 #include <vm/vm_param.h>
83 #include <vm/vm_map.h>
84 #include <vm/vm_kern.h>
85 #include <vm/vm_extern.h>
86 #include <vm/uma.h>
87 #include <vm/uma_int.h>
88 #include <vm/uma_dbg.h>
89 
90 #include <ddb/ddb.h>
91 
92 #ifdef DEBUG_MEMGUARD
93 #include <vm/memguard.h>
94 #endif
95 
96 /*
97  * This is the zone and keg from which all zones are spawned.  The idea is that
98  * even the zone & keg heads are allocated from the allocator, so we use the
99  * bss section to bootstrap us.
100  */
101 static struct uma_keg masterkeg;
102 static struct uma_zone masterzone_k;
103 static struct uma_zone masterzone_z;
104 static uma_zone_t kegs = &masterzone_k;
105 static uma_zone_t zones = &masterzone_z;
106 
107 /* This is the zone from which all of uma_slab_t's are allocated. */
108 static uma_zone_t slabzone;
109 
110 /*
111  * The initial hash tables come out of this zone so they can be allocated
112  * prior to malloc coming up.
113  */
114 static uma_zone_t hashzone;
115 
116 /* The boot-time adjusted value for cache line alignment. */
117 int uma_align_cache = 64 - 1;
118 
119 static MALLOC_DEFINE(M_UMAHASH, "UMAHash", "UMA Hash Buckets");
120 
121 /*
122  * Are we allowed to allocate buckets?
123  */
124 static int bucketdisable = 1;
125 
126 /* Linked list of all kegs in the system */
127 static LIST_HEAD(,uma_keg) uma_kegs = LIST_HEAD_INITIALIZER(uma_kegs);
128 
129 /* Linked list of all cache-only zones in the system */
130 static LIST_HEAD(,uma_zone) uma_cachezones =
131     LIST_HEAD_INITIALIZER(uma_cachezones);
132 
133 /* This RW lock protects the keg list */
134 static struct rwlock_padalign __exclusive_cache_line uma_rwlock;
135 
136 /*
137  * Pointer and counter to pool of pages, that is preallocated at
138  * startup to bootstrap UMA.  Early zones continue to use the pool
139  * until it is depleted, so allocations may happen after boot, thus
140  * we need a mutex to protect it.
141  */
142 static char *bootmem;
143 static int boot_pages;
144 static struct mtx uma_boot_pages_mtx;
145 
146 static struct sx uma_drain_lock;
147 
148 /* Is the VM done starting up? */
149 static int booted = 0;
150 #define	UMA_STARTUP	1
151 #define	UMA_STARTUP2	2
152 
153 /*
154  * This is the handle used to schedule events that need to happen
155  * outside of the allocation fast path.
156  */
157 static struct callout uma_callout;
158 #define	UMA_TIMEOUT	20		/* Seconds for callout interval. */
159 
160 /*
161  * This structure is passed as the zone ctor arg so that I don't have to create
162  * a special allocation function just for zones.
163  */
164 struct uma_zctor_args {
165 	const char *name;
166 	size_t size;
167 	uma_ctor ctor;
168 	uma_dtor dtor;
169 	uma_init uminit;
170 	uma_fini fini;
171 	uma_import import;
172 	uma_release release;
173 	void *arg;
174 	uma_keg_t keg;
175 	int align;
176 	uint32_t flags;
177 };
178 
179 struct uma_kctor_args {
180 	uma_zone_t zone;
181 	size_t size;
182 	uma_init uminit;
183 	uma_fini fini;
184 	int align;
185 	uint32_t flags;
186 };
187 
188 struct uma_bucket_zone {
189 	uma_zone_t	ubz_zone;
190 	char		*ubz_name;
191 	int		ubz_entries;	/* Number of items it can hold. */
192 	int		ubz_maxsize;	/* Maximum allocation size per-item. */
193 };
194 
195 /*
196  * Compute the actual number of bucket entries to pack them in power
197  * of two sizes for more efficient space utilization.
198  */
199 #define	BUCKET_SIZE(n)						\
200     (((sizeof(void *) * (n)) - sizeof(struct uma_bucket)) / sizeof(void *))
201 
202 #define	BUCKET_MAX	BUCKET_SIZE(256)
203 
204 struct uma_bucket_zone bucket_zones[] = {
205 	{ NULL, "4 Bucket", BUCKET_SIZE(4), 4096 },
206 	{ NULL, "6 Bucket", BUCKET_SIZE(6), 3072 },
207 	{ NULL, "8 Bucket", BUCKET_SIZE(8), 2048 },
208 	{ NULL, "12 Bucket", BUCKET_SIZE(12), 1536 },
209 	{ NULL, "16 Bucket", BUCKET_SIZE(16), 1024 },
210 	{ NULL, "32 Bucket", BUCKET_SIZE(32), 512 },
211 	{ NULL, "64 Bucket", BUCKET_SIZE(64), 256 },
212 	{ NULL, "128 Bucket", BUCKET_SIZE(128), 128 },
213 	{ NULL, "256 Bucket", BUCKET_SIZE(256), 64 },
214 	{ NULL, NULL, 0}
215 };
216 
217 /*
218  * Flags and enumerations to be passed to internal functions.
219  */
220 enum zfreeskip { SKIP_NONE = 0, SKIP_DTOR, SKIP_FINI };
221 
222 /* Prototypes.. */
223 
224 static void *noobj_alloc(uma_zone_t, vm_size_t, uint8_t *, int);
225 static void *page_alloc(uma_zone_t, vm_size_t, uint8_t *, int);
226 static void *startup_alloc(uma_zone_t, vm_size_t, uint8_t *, int);
227 static void page_free(void *, vm_size_t, uint8_t);
228 static uma_slab_t keg_alloc_slab(uma_keg_t, uma_zone_t, int);
229 static void cache_drain(uma_zone_t);
230 static void bucket_drain(uma_zone_t, uma_bucket_t);
231 static void bucket_cache_drain(uma_zone_t zone);
232 static int keg_ctor(void *, int, void *, int);
233 static void keg_dtor(void *, int, void *);
234 static int zone_ctor(void *, int, void *, int);
235 static void zone_dtor(void *, int, void *);
236 static int zero_init(void *, int, int);
237 static void keg_small_init(uma_keg_t keg);
238 static void keg_large_init(uma_keg_t keg);
239 static void zone_foreach(void (*zfunc)(uma_zone_t));
240 static void zone_timeout(uma_zone_t zone);
241 static int hash_alloc(struct uma_hash *);
242 static int hash_expand(struct uma_hash *, struct uma_hash *);
243 static void hash_free(struct uma_hash *hash);
244 static void uma_timeout(void *);
245 static void uma_startup3(void);
246 static void *zone_alloc_item(uma_zone_t, void *, int);
247 static void zone_free_item(uma_zone_t, void *, void *, enum zfreeskip);
248 static void bucket_enable(void);
249 static void bucket_init(void);
250 static uma_bucket_t bucket_alloc(uma_zone_t zone, void *, int);
251 static void bucket_free(uma_zone_t zone, uma_bucket_t, void *);
252 static void bucket_zone_drain(void);
253 static uma_bucket_t zone_alloc_bucket(uma_zone_t zone, void *, int flags);
254 static uma_slab_t zone_fetch_slab(uma_zone_t zone, uma_keg_t last, int flags);
255 static uma_slab_t zone_fetch_slab_multi(uma_zone_t zone, uma_keg_t last, int flags);
256 static void *slab_alloc_item(uma_keg_t keg, uma_slab_t slab);
257 static void slab_free_item(uma_keg_t keg, uma_slab_t slab, void *item);
258 static uma_keg_t uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit,
259     uma_fini fini, int align, uint32_t flags);
260 static int zone_import(uma_zone_t zone, void **bucket, int max, int flags);
261 static void zone_release(uma_zone_t zone, void **bucket, int cnt);
262 static void uma_zero_item(void *item, uma_zone_t zone);
263 
264 void uma_print_zone(uma_zone_t);
265 void uma_print_stats(void);
266 static int sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS);
267 static int sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS);
268 
269 #ifdef INVARIANTS
270 static void uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item);
271 static void uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item);
272 #endif
273 
274 SYSINIT(uma_startup3, SI_SUB_VM_CONF, SI_ORDER_SECOND, uma_startup3, NULL);
275 
276 SYSCTL_PROC(_vm, OID_AUTO, zone_count, CTLFLAG_RD|CTLTYPE_INT,
277     0, 0, sysctl_vm_zone_count, "I", "Number of UMA zones");
278 
279 SYSCTL_PROC(_vm, OID_AUTO, zone_stats, CTLFLAG_RD|CTLTYPE_STRUCT,
280     0, 0, sysctl_vm_zone_stats, "s,struct uma_type_header", "Zone Stats");
281 
282 static int zone_warnings = 1;
283 SYSCTL_INT(_vm, OID_AUTO, zone_warnings, CTLFLAG_RWTUN, &zone_warnings, 0,
284     "Warn when UMA zones becomes full");
285 
286 /*
287  * This routine checks to see whether or not it's safe to enable buckets.
288  */
289 static void
290 bucket_enable(void)
291 {
292 	bucketdisable = vm_page_count_min();
293 }
294 
295 /*
296  * Initialize bucket_zones, the array of zones of buckets of various sizes.
297  *
298  * For each zone, calculate the memory required for each bucket, consisting
299  * of the header and an array of pointers.
300  */
301 static void
302 bucket_init(void)
303 {
304 	struct uma_bucket_zone *ubz;
305 	int size;
306 
307 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++) {
308 		size = roundup(sizeof(struct uma_bucket), sizeof(void *));
309 		size += sizeof(void *) * ubz->ubz_entries;
310 		ubz->ubz_zone = uma_zcreate(ubz->ubz_name, size,
311 		    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR,
312 		    UMA_ZONE_MTXCLASS | UMA_ZFLAG_BUCKET);
313 	}
314 }
315 
316 /*
317  * Given a desired number of entries for a bucket, return the zone from which
318  * to allocate the bucket.
319  */
320 static struct uma_bucket_zone *
321 bucket_zone_lookup(int entries)
322 {
323 	struct uma_bucket_zone *ubz;
324 
325 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
326 		if (ubz->ubz_entries >= entries)
327 			return (ubz);
328 	ubz--;
329 	return (ubz);
330 }
331 
332 static int
333 bucket_select(int size)
334 {
335 	struct uma_bucket_zone *ubz;
336 
337 	ubz = &bucket_zones[0];
338 	if (size > ubz->ubz_maxsize)
339 		return MAX((ubz->ubz_maxsize * ubz->ubz_entries) / size, 1);
340 
341 	for (; ubz->ubz_entries != 0; ubz++)
342 		if (ubz->ubz_maxsize < size)
343 			break;
344 	ubz--;
345 	return (ubz->ubz_entries);
346 }
347 
348 static uma_bucket_t
349 bucket_alloc(uma_zone_t zone, void *udata, int flags)
350 {
351 	struct uma_bucket_zone *ubz;
352 	uma_bucket_t bucket;
353 
354 	/*
355 	 * This is to stop us from allocating per cpu buckets while we're
356 	 * running out of vm.boot_pages.  Otherwise, we would exhaust the
357 	 * boot pages.  This also prevents us from allocating buckets in
358 	 * low memory situations.
359 	 */
360 	if (bucketdisable)
361 		return (NULL);
362 	/*
363 	 * To limit bucket recursion we store the original zone flags
364 	 * in a cookie passed via zalloc_arg/zfree_arg.  This allows the
365 	 * NOVM flag to persist even through deep recursions.  We also
366 	 * store ZFLAG_BUCKET once we have recursed attempting to allocate
367 	 * a bucket for a bucket zone so we do not allow infinite bucket
368 	 * recursion.  This cookie will even persist to frees of unused
369 	 * buckets via the allocation path or bucket allocations in the
370 	 * free path.
371 	 */
372 	if ((zone->uz_flags & UMA_ZFLAG_BUCKET) == 0)
373 		udata = (void *)(uintptr_t)zone->uz_flags;
374 	else {
375 		if ((uintptr_t)udata & UMA_ZFLAG_BUCKET)
376 			return (NULL);
377 		udata = (void *)((uintptr_t)udata | UMA_ZFLAG_BUCKET);
378 	}
379 	if ((uintptr_t)udata & UMA_ZFLAG_CACHEONLY)
380 		flags |= M_NOVM;
381 	ubz = bucket_zone_lookup(zone->uz_count);
382 	if (ubz->ubz_zone == zone && (ubz + 1)->ubz_entries != 0)
383 		ubz++;
384 	bucket = uma_zalloc_arg(ubz->ubz_zone, udata, flags);
385 	if (bucket) {
386 #ifdef INVARIANTS
387 		bzero(bucket->ub_bucket, sizeof(void *) * ubz->ubz_entries);
388 #endif
389 		bucket->ub_cnt = 0;
390 		bucket->ub_entries = ubz->ubz_entries;
391 	}
392 
393 	return (bucket);
394 }
395 
396 static void
397 bucket_free(uma_zone_t zone, uma_bucket_t bucket, void *udata)
398 {
399 	struct uma_bucket_zone *ubz;
400 
401 	KASSERT(bucket->ub_cnt == 0,
402 	    ("bucket_free: Freeing a non free bucket."));
403 	if ((zone->uz_flags & UMA_ZFLAG_BUCKET) == 0)
404 		udata = (void *)(uintptr_t)zone->uz_flags;
405 	ubz = bucket_zone_lookup(bucket->ub_entries);
406 	uma_zfree_arg(ubz->ubz_zone, bucket, udata);
407 }
408 
409 static void
410 bucket_zone_drain(void)
411 {
412 	struct uma_bucket_zone *ubz;
413 
414 	for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
415 		zone_drain(ubz->ubz_zone);
416 }
417 
418 static void
419 zone_log_warning(uma_zone_t zone)
420 {
421 	static const struct timeval warninterval = { 300, 0 };
422 
423 	if (!zone_warnings || zone->uz_warning == NULL)
424 		return;
425 
426 	if (ratecheck(&zone->uz_ratecheck, &warninterval))
427 		printf("[zone: %s] %s\n", zone->uz_name, zone->uz_warning);
428 }
429 
430 static inline void
431 zone_maxaction(uma_zone_t zone)
432 {
433 
434 	if (zone->uz_maxaction.ta_func != NULL)
435 		taskqueue_enqueue(taskqueue_thread, &zone->uz_maxaction);
436 }
437 
438 static void
439 zone_foreach_keg(uma_zone_t zone, void (*kegfn)(uma_keg_t))
440 {
441 	uma_klink_t klink;
442 
443 	LIST_FOREACH(klink, &zone->uz_kegs, kl_link)
444 		kegfn(klink->kl_keg);
445 }
446 
447 /*
448  * Routine called by timeout which is used to fire off some time interval
449  * based calculations.  (stats, hash size, etc.)
450  *
451  * Arguments:
452  *	arg   Unused
453  *
454  * Returns:
455  *	Nothing
456  */
457 static void
458 uma_timeout(void *unused)
459 {
460 	bucket_enable();
461 	zone_foreach(zone_timeout);
462 
463 	/* Reschedule this event */
464 	callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
465 }
466 
467 /*
468  * Routine to perform timeout driven calculations.  This expands the
469  * hashes and does per cpu statistics aggregation.
470  *
471  *  Returns nothing.
472  */
473 static void
474 keg_timeout(uma_keg_t keg)
475 {
476 
477 	KEG_LOCK(keg);
478 	/*
479 	 * Expand the keg hash table.
480 	 *
481 	 * This is done if the number of slabs is larger than the hash size.
482 	 * What I'm trying to do here is completely reduce collisions.  This
483 	 * may be a little aggressive.  Should I allow for two collisions max?
484 	 */
485 	if (keg->uk_flags & UMA_ZONE_HASH &&
486 	    keg->uk_pages / keg->uk_ppera >= keg->uk_hash.uh_hashsize) {
487 		struct uma_hash newhash;
488 		struct uma_hash oldhash;
489 		int ret;
490 
491 		/*
492 		 * This is so involved because allocating and freeing
493 		 * while the keg lock is held will lead to deadlock.
494 		 * I have to do everything in stages and check for
495 		 * races.
496 		 */
497 		newhash = keg->uk_hash;
498 		KEG_UNLOCK(keg);
499 		ret = hash_alloc(&newhash);
500 		KEG_LOCK(keg);
501 		if (ret) {
502 			if (hash_expand(&keg->uk_hash, &newhash)) {
503 				oldhash = keg->uk_hash;
504 				keg->uk_hash = newhash;
505 			} else
506 				oldhash = newhash;
507 
508 			KEG_UNLOCK(keg);
509 			hash_free(&oldhash);
510 			return;
511 		}
512 	}
513 	KEG_UNLOCK(keg);
514 }
515 
516 static void
517 zone_timeout(uma_zone_t zone)
518 {
519 
520 	zone_foreach_keg(zone, &keg_timeout);
521 }
522 
523 /*
524  * Allocate and zero fill the next sized hash table from the appropriate
525  * backing store.
526  *
527  * Arguments:
528  *	hash  A new hash structure with the old hash size in uh_hashsize
529  *
530  * Returns:
531  *	1 on success and 0 on failure.
532  */
533 static int
534 hash_alloc(struct uma_hash *hash)
535 {
536 	int oldsize;
537 	int alloc;
538 
539 	oldsize = hash->uh_hashsize;
540 
541 	/* We're just going to go to a power of two greater */
542 	if (oldsize)  {
543 		hash->uh_hashsize = oldsize * 2;
544 		alloc = sizeof(hash->uh_slab_hash[0]) * hash->uh_hashsize;
545 		hash->uh_slab_hash = (struct slabhead *)malloc(alloc,
546 		    M_UMAHASH, M_NOWAIT);
547 	} else {
548 		alloc = sizeof(hash->uh_slab_hash[0]) * UMA_HASH_SIZE_INIT;
549 		hash->uh_slab_hash = zone_alloc_item(hashzone, NULL,
550 		    M_WAITOK);
551 		hash->uh_hashsize = UMA_HASH_SIZE_INIT;
552 	}
553 	if (hash->uh_slab_hash) {
554 		bzero(hash->uh_slab_hash, alloc);
555 		hash->uh_hashmask = hash->uh_hashsize - 1;
556 		return (1);
557 	}
558 
559 	return (0);
560 }
561 
562 /*
563  * Expands the hash table for HASH zones.  This is done from zone_timeout
564  * to reduce collisions.  This must not be done in the regular allocation
565  * path, otherwise, we can recurse on the vm while allocating pages.
566  *
567  * Arguments:
568  *	oldhash  The hash you want to expand
569  *	newhash  The hash structure for the new table
570  *
571  * Returns:
572  *	Nothing
573  *
574  * Discussion:
575  */
576 static int
577 hash_expand(struct uma_hash *oldhash, struct uma_hash *newhash)
578 {
579 	uma_slab_t slab;
580 	int hval;
581 	int i;
582 
583 	if (!newhash->uh_slab_hash)
584 		return (0);
585 
586 	if (oldhash->uh_hashsize >= newhash->uh_hashsize)
587 		return (0);
588 
589 	/*
590 	 * I need to investigate hash algorithms for resizing without a
591 	 * full rehash.
592 	 */
593 
594 	for (i = 0; i < oldhash->uh_hashsize; i++)
595 		while (!SLIST_EMPTY(&oldhash->uh_slab_hash[i])) {
596 			slab = SLIST_FIRST(&oldhash->uh_slab_hash[i]);
597 			SLIST_REMOVE_HEAD(&oldhash->uh_slab_hash[i], us_hlink);
598 			hval = UMA_HASH(newhash, slab->us_data);
599 			SLIST_INSERT_HEAD(&newhash->uh_slab_hash[hval],
600 			    slab, us_hlink);
601 		}
602 
603 	return (1);
604 }
605 
606 /*
607  * Free the hash bucket to the appropriate backing store.
608  *
609  * Arguments:
610  *	slab_hash  The hash bucket we're freeing
611  *	hashsize   The number of entries in that hash bucket
612  *
613  * Returns:
614  *	Nothing
615  */
616 static void
617 hash_free(struct uma_hash *hash)
618 {
619 	if (hash->uh_slab_hash == NULL)
620 		return;
621 	if (hash->uh_hashsize == UMA_HASH_SIZE_INIT)
622 		zone_free_item(hashzone, hash->uh_slab_hash, NULL, SKIP_NONE);
623 	else
624 		free(hash->uh_slab_hash, M_UMAHASH);
625 }
626 
627 /*
628  * Frees all outstanding items in a bucket
629  *
630  * Arguments:
631  *	zone   The zone to free to, must be unlocked.
632  *	bucket The free/alloc bucket with items, cpu queue must be locked.
633  *
634  * Returns:
635  *	Nothing
636  */
637 
638 static void
639 bucket_drain(uma_zone_t zone, uma_bucket_t bucket)
640 {
641 	int i;
642 
643 	if (bucket == NULL)
644 		return;
645 
646 	if (zone->uz_fini)
647 		for (i = 0; i < bucket->ub_cnt; i++)
648 			zone->uz_fini(bucket->ub_bucket[i], zone->uz_size);
649 	zone->uz_release(zone->uz_arg, bucket->ub_bucket, bucket->ub_cnt);
650 	bucket->ub_cnt = 0;
651 }
652 
653 /*
654  * Drains the per cpu caches for a zone.
655  *
656  * NOTE: This may only be called while the zone is being turn down, and not
657  * during normal operation.  This is necessary in order that we do not have
658  * to migrate CPUs to drain the per-CPU caches.
659  *
660  * Arguments:
661  *	zone     The zone to drain, must be unlocked.
662  *
663  * Returns:
664  *	Nothing
665  */
666 static void
667 cache_drain(uma_zone_t zone)
668 {
669 	uma_cache_t cache;
670 	int cpu;
671 
672 	/*
673 	 * XXX: It is safe to not lock the per-CPU caches, because we're
674 	 * tearing down the zone anyway.  I.e., there will be no further use
675 	 * of the caches at this point.
676 	 *
677 	 * XXX: It would good to be able to assert that the zone is being
678 	 * torn down to prevent improper use of cache_drain().
679 	 *
680 	 * XXX: We lock the zone before passing into bucket_cache_drain() as
681 	 * it is used elsewhere.  Should the tear-down path be made special
682 	 * there in some form?
683 	 */
684 	CPU_FOREACH(cpu) {
685 		cache = &zone->uz_cpu[cpu];
686 		bucket_drain(zone, cache->uc_allocbucket);
687 		bucket_drain(zone, cache->uc_freebucket);
688 		if (cache->uc_allocbucket != NULL)
689 			bucket_free(zone, cache->uc_allocbucket, NULL);
690 		if (cache->uc_freebucket != NULL)
691 			bucket_free(zone, cache->uc_freebucket, NULL);
692 		cache->uc_allocbucket = cache->uc_freebucket = NULL;
693 	}
694 	ZONE_LOCK(zone);
695 	bucket_cache_drain(zone);
696 	ZONE_UNLOCK(zone);
697 }
698 
699 static void
700 cache_shrink(uma_zone_t zone)
701 {
702 
703 	if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
704 		return;
705 
706 	ZONE_LOCK(zone);
707 	zone->uz_count = (zone->uz_count_min + zone->uz_count) / 2;
708 	ZONE_UNLOCK(zone);
709 }
710 
711 static void
712 cache_drain_safe_cpu(uma_zone_t zone)
713 {
714 	uma_cache_t cache;
715 	uma_bucket_t b1, b2;
716 
717 	if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
718 		return;
719 
720 	b1 = b2 = NULL;
721 	ZONE_LOCK(zone);
722 	critical_enter();
723 	cache = &zone->uz_cpu[curcpu];
724 	if (cache->uc_allocbucket) {
725 		if (cache->uc_allocbucket->ub_cnt != 0)
726 			LIST_INSERT_HEAD(&zone->uz_buckets,
727 			    cache->uc_allocbucket, ub_link);
728 		else
729 			b1 = cache->uc_allocbucket;
730 		cache->uc_allocbucket = NULL;
731 	}
732 	if (cache->uc_freebucket) {
733 		if (cache->uc_freebucket->ub_cnt != 0)
734 			LIST_INSERT_HEAD(&zone->uz_buckets,
735 			    cache->uc_freebucket, ub_link);
736 		else
737 			b2 = cache->uc_freebucket;
738 		cache->uc_freebucket = NULL;
739 	}
740 	critical_exit();
741 	ZONE_UNLOCK(zone);
742 	if (b1)
743 		bucket_free(zone, b1, NULL);
744 	if (b2)
745 		bucket_free(zone, b2, NULL);
746 }
747 
748 /*
749  * Safely drain per-CPU caches of a zone(s) to alloc bucket.
750  * This is an expensive call because it needs to bind to all CPUs
751  * one by one and enter a critical section on each of them in order
752  * to safely access their cache buckets.
753  * Zone lock must not be held on call this function.
754  */
755 static void
756 cache_drain_safe(uma_zone_t zone)
757 {
758 	int cpu;
759 
760 	/*
761 	 * Polite bucket sizes shrinking was not enouth, shrink aggressively.
762 	 */
763 	if (zone)
764 		cache_shrink(zone);
765 	else
766 		zone_foreach(cache_shrink);
767 
768 	CPU_FOREACH(cpu) {
769 		thread_lock(curthread);
770 		sched_bind(curthread, cpu);
771 		thread_unlock(curthread);
772 
773 		if (zone)
774 			cache_drain_safe_cpu(zone);
775 		else
776 			zone_foreach(cache_drain_safe_cpu);
777 	}
778 	thread_lock(curthread);
779 	sched_unbind(curthread);
780 	thread_unlock(curthread);
781 }
782 
783 /*
784  * Drain the cached buckets from a zone.  Expects a locked zone on entry.
785  */
786 static void
787 bucket_cache_drain(uma_zone_t zone)
788 {
789 	uma_bucket_t bucket;
790 
791 	/*
792 	 * Drain the bucket queues and free the buckets, we just keep two per
793 	 * cpu (alloc/free).
794 	 */
795 	while ((bucket = LIST_FIRST(&zone->uz_buckets)) != NULL) {
796 		LIST_REMOVE(bucket, ub_link);
797 		ZONE_UNLOCK(zone);
798 		bucket_drain(zone, bucket);
799 		bucket_free(zone, bucket, NULL);
800 		ZONE_LOCK(zone);
801 	}
802 
803 	/*
804 	 * Shrink further bucket sizes.  Price of single zone lock collision
805 	 * is probably lower then price of global cache drain.
806 	 */
807 	if (zone->uz_count > zone->uz_count_min)
808 		zone->uz_count--;
809 }
810 
811 static void
812 keg_free_slab(uma_keg_t keg, uma_slab_t slab, int start)
813 {
814 	uint8_t *mem;
815 	int i;
816 	uint8_t flags;
817 
818 	CTR4(KTR_UMA, "keg_free_slab keg %s(%p) slab %p, returning %d bytes",
819 	    keg->uk_name, keg, slab, PAGE_SIZE * keg->uk_ppera);
820 
821 	mem = slab->us_data;
822 	flags = slab->us_flags;
823 	i = start;
824 	if (keg->uk_fini != NULL) {
825 		for (i--; i > -1; i--)
826 			keg->uk_fini(slab->us_data + (keg->uk_rsize * i),
827 			    keg->uk_size);
828 	}
829 	if (keg->uk_flags & UMA_ZONE_OFFPAGE)
830 		zone_free_item(keg->uk_slabzone, slab, NULL, SKIP_NONE);
831 	keg->uk_freef(mem, PAGE_SIZE * keg->uk_ppera, flags);
832 }
833 
834 /*
835  * Frees pages from a keg back to the system.  This is done on demand from
836  * the pageout daemon.
837  *
838  * Returns nothing.
839  */
840 static void
841 keg_drain(uma_keg_t keg)
842 {
843 	struct slabhead freeslabs = { 0 };
844 	uma_slab_t slab, tmp;
845 
846 	/*
847 	 * We don't want to take pages from statically allocated kegs at this
848 	 * time
849 	 */
850 	if (keg->uk_flags & UMA_ZONE_NOFREE || keg->uk_freef == NULL)
851 		return;
852 
853 	CTR3(KTR_UMA, "keg_drain %s(%p) free items: %u",
854 	    keg->uk_name, keg, keg->uk_free);
855 	KEG_LOCK(keg);
856 	if (keg->uk_free == 0)
857 		goto finished;
858 
859 	LIST_FOREACH_SAFE(slab, &keg->uk_free_slab, us_link, tmp) {
860 		/* We have nowhere to free these to. */
861 		if (slab->us_flags & UMA_SLAB_BOOT)
862 			continue;
863 
864 		LIST_REMOVE(slab, us_link);
865 		keg->uk_pages -= keg->uk_ppera;
866 		keg->uk_free -= keg->uk_ipers;
867 
868 		if (keg->uk_flags & UMA_ZONE_HASH)
869 			UMA_HASH_REMOVE(&keg->uk_hash, slab, slab->us_data);
870 
871 		SLIST_INSERT_HEAD(&freeslabs, slab, us_hlink);
872 	}
873 finished:
874 	KEG_UNLOCK(keg);
875 
876 	while ((slab = SLIST_FIRST(&freeslabs)) != NULL) {
877 		SLIST_REMOVE(&freeslabs, slab, uma_slab, us_hlink);
878 		keg_free_slab(keg, slab, keg->uk_ipers);
879 	}
880 }
881 
882 static void
883 zone_drain_wait(uma_zone_t zone, int waitok)
884 {
885 
886 	/*
887 	 * Set draining to interlock with zone_dtor() so we can release our
888 	 * locks as we go.  Only dtor() should do a WAITOK call since it
889 	 * is the only call that knows the structure will still be available
890 	 * when it wakes up.
891 	 */
892 	ZONE_LOCK(zone);
893 	while (zone->uz_flags & UMA_ZFLAG_DRAINING) {
894 		if (waitok == M_NOWAIT)
895 			goto out;
896 		msleep(zone, zone->uz_lockptr, PVM, "zonedrain", 1);
897 	}
898 	zone->uz_flags |= UMA_ZFLAG_DRAINING;
899 	bucket_cache_drain(zone);
900 	ZONE_UNLOCK(zone);
901 	/*
902 	 * The DRAINING flag protects us from being freed while
903 	 * we're running.  Normally the uma_rwlock would protect us but we
904 	 * must be able to release and acquire the right lock for each keg.
905 	 */
906 	zone_foreach_keg(zone, &keg_drain);
907 	ZONE_LOCK(zone);
908 	zone->uz_flags &= ~UMA_ZFLAG_DRAINING;
909 	wakeup(zone);
910 out:
911 	ZONE_UNLOCK(zone);
912 }
913 
914 void
915 zone_drain(uma_zone_t zone)
916 {
917 
918 	zone_drain_wait(zone, M_NOWAIT);
919 }
920 
921 /*
922  * Allocate a new slab for a keg.  This does not insert the slab onto a list.
923  *
924  * Arguments:
925  *	wait  Shall we wait?
926  *
927  * Returns:
928  *	The slab that was allocated or NULL if there is no memory and the
929  *	caller specified M_NOWAIT.
930  */
931 static uma_slab_t
932 keg_alloc_slab(uma_keg_t keg, uma_zone_t zone, int wait)
933 {
934 	uma_alloc allocf;
935 	uma_slab_t slab;
936 	uint8_t *mem;
937 	uint8_t flags;
938 	int i;
939 
940 	mtx_assert(&keg->uk_lock, MA_OWNED);
941 	slab = NULL;
942 	mem = NULL;
943 
944 	allocf = keg->uk_allocf;
945 	KEG_UNLOCK(keg);
946 
947 	if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
948 		slab = zone_alloc_item(keg->uk_slabzone, NULL, wait);
949 		if (slab == NULL)
950 			goto out;
951 	}
952 
953 	/*
954 	 * This reproduces the old vm_zone behavior of zero filling pages the
955 	 * first time they are added to a zone.
956 	 *
957 	 * Malloced items are zeroed in uma_zalloc.
958 	 */
959 
960 	if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
961 		wait |= M_ZERO;
962 	else
963 		wait &= ~M_ZERO;
964 
965 	if (keg->uk_flags & UMA_ZONE_NODUMP)
966 		wait |= M_NODUMP;
967 
968 	/* zone is passed for legacy reasons. */
969 	mem = allocf(zone, keg->uk_ppera * PAGE_SIZE, &flags, wait);
970 	if (mem == NULL) {
971 		if (keg->uk_flags & UMA_ZONE_OFFPAGE)
972 			zone_free_item(keg->uk_slabzone, slab, NULL, SKIP_NONE);
973 		slab = NULL;
974 		goto out;
975 	}
976 
977 	/* Point the slab into the allocated memory */
978 	if (!(keg->uk_flags & UMA_ZONE_OFFPAGE))
979 		slab = (uma_slab_t )(mem + keg->uk_pgoff);
980 
981 	if (keg->uk_flags & UMA_ZONE_VTOSLAB)
982 		for (i = 0; i < keg->uk_ppera; i++)
983 			vsetslab((vm_offset_t)mem + (i * PAGE_SIZE), slab);
984 
985 	slab->us_keg = keg;
986 	slab->us_data = mem;
987 	slab->us_freecount = keg->uk_ipers;
988 	slab->us_flags = flags;
989 	BIT_FILL(SLAB_SETSIZE, &slab->us_free);
990 #ifdef INVARIANTS
991 	BIT_ZERO(SLAB_SETSIZE, &slab->us_debugfree);
992 #endif
993 
994 	if (keg->uk_init != NULL) {
995 		for (i = 0; i < keg->uk_ipers; i++)
996 			if (keg->uk_init(slab->us_data + (keg->uk_rsize * i),
997 			    keg->uk_size, wait) != 0)
998 				break;
999 		if (i != keg->uk_ipers) {
1000 			keg_free_slab(keg, slab, i);
1001 			slab = NULL;
1002 			goto out;
1003 		}
1004 	}
1005 out:
1006 	KEG_LOCK(keg);
1007 
1008 	CTR3(KTR_UMA, "keg_alloc_slab: allocated slab %p for %s(%p)",
1009 	    slab, keg->uk_name, keg);
1010 
1011 	if (slab != NULL) {
1012 		if (keg->uk_flags & UMA_ZONE_HASH)
1013 			UMA_HASH_INSERT(&keg->uk_hash, slab, mem);
1014 
1015 		keg->uk_pages += keg->uk_ppera;
1016 		keg->uk_free += keg->uk_ipers;
1017 	}
1018 
1019 	return (slab);
1020 }
1021 
1022 /*
1023  * This function is intended to be used early on in place of page_alloc() so
1024  * that we may use the boot time page cache to satisfy allocations before
1025  * the VM is ready.
1026  */
1027 static void *
1028 startup_alloc(uma_zone_t zone, vm_size_t bytes, uint8_t *pflag, int wait)
1029 {
1030 	uma_keg_t keg;
1031 	void *mem;
1032 	int pages;
1033 
1034 	keg = zone_first_keg(zone);
1035 	pages = howmany(bytes, PAGE_SIZE);
1036 	KASSERT(pages > 0, ("startup_alloc can't reserve 0 pages\n"));
1037 
1038 	/*
1039 	 * Check our small startup cache to see if it has pages remaining.
1040 	 */
1041 	mtx_lock(&uma_boot_pages_mtx);
1042 	if (pages <= boot_pages) {
1043 		mem = bootmem;
1044 		boot_pages -= pages;
1045 		bootmem += pages * PAGE_SIZE;
1046 		mtx_unlock(&uma_boot_pages_mtx);
1047 		*pflag = UMA_SLAB_BOOT;
1048 		return (mem);
1049 	}
1050 	mtx_unlock(&uma_boot_pages_mtx);
1051 	if (booted < UMA_STARTUP2)
1052 		panic("UMA: Increase vm.boot_pages");
1053 	/*
1054 	 * Now that we've booted reset these users to their real allocator.
1055 	 */
1056 #ifdef UMA_MD_SMALL_ALLOC
1057 	keg->uk_allocf = (keg->uk_ppera > 1) ? page_alloc : uma_small_alloc;
1058 #else
1059 	keg->uk_allocf = page_alloc;
1060 #endif
1061 	return keg->uk_allocf(zone, bytes, pflag, wait);
1062 }
1063 
1064 /*
1065  * Allocates a number of pages from the system
1066  *
1067  * Arguments:
1068  *	bytes  The number of bytes requested
1069  *	wait  Shall we wait?
1070  *
1071  * Returns:
1072  *	A pointer to the alloced memory or possibly
1073  *	NULL if M_NOWAIT is set.
1074  */
1075 static void *
1076 page_alloc(uma_zone_t zone, vm_size_t bytes, uint8_t *pflag, int wait)
1077 {
1078 	void *p;	/* Returned page */
1079 
1080 	*pflag = UMA_SLAB_KMEM;
1081 	p = (void *) kmem_malloc(kmem_arena, bytes, wait);
1082 
1083 	return (p);
1084 }
1085 
1086 /*
1087  * Allocates a number of pages from within an object
1088  *
1089  * Arguments:
1090  *	bytes  The number of bytes requested
1091  *	wait   Shall we wait?
1092  *
1093  * Returns:
1094  *	A pointer to the alloced memory or possibly
1095  *	NULL if M_NOWAIT is set.
1096  */
1097 static void *
1098 noobj_alloc(uma_zone_t zone, vm_size_t bytes, uint8_t *flags, int wait)
1099 {
1100 	TAILQ_HEAD(, vm_page) alloctail;
1101 	u_long npages;
1102 	vm_offset_t retkva, zkva;
1103 	vm_page_t p, p_next;
1104 	uma_keg_t keg;
1105 
1106 	TAILQ_INIT(&alloctail);
1107 	keg = zone_first_keg(zone);
1108 
1109 	npages = howmany(bytes, PAGE_SIZE);
1110 	while (npages > 0) {
1111 		p = vm_page_alloc(NULL, 0, VM_ALLOC_INTERRUPT |
1112 		    VM_ALLOC_WIRED | VM_ALLOC_NOOBJ |
1113 		    ((wait & M_WAITOK) != 0 ? VM_ALLOC_WAITOK :
1114 		    VM_ALLOC_NOWAIT));
1115 		if (p != NULL) {
1116 			/*
1117 			 * Since the page does not belong to an object, its
1118 			 * listq is unused.
1119 			 */
1120 			TAILQ_INSERT_TAIL(&alloctail, p, listq);
1121 			npages--;
1122 			continue;
1123 		}
1124 		/*
1125 		 * Page allocation failed, free intermediate pages and
1126 		 * exit.
1127 		 */
1128 		TAILQ_FOREACH_SAFE(p, &alloctail, listq, p_next) {
1129 			vm_page_unwire(p, PQ_NONE);
1130 			vm_page_free(p);
1131 		}
1132 		return (NULL);
1133 	}
1134 	*flags = UMA_SLAB_PRIV;
1135 	zkva = keg->uk_kva +
1136 	    atomic_fetchadd_long(&keg->uk_offset, round_page(bytes));
1137 	retkva = zkva;
1138 	TAILQ_FOREACH(p, &alloctail, listq) {
1139 		pmap_qenter(zkva, &p, 1);
1140 		zkva += PAGE_SIZE;
1141 	}
1142 
1143 	return ((void *)retkva);
1144 }
1145 
1146 /*
1147  * Frees a number of pages to the system
1148  *
1149  * Arguments:
1150  *	mem   A pointer to the memory to be freed
1151  *	size  The size of the memory being freed
1152  *	flags The original p->us_flags field
1153  *
1154  * Returns:
1155  *	Nothing
1156  */
1157 static void
1158 page_free(void *mem, vm_size_t size, uint8_t flags)
1159 {
1160 	struct vmem *vmem;
1161 
1162 	if (flags & UMA_SLAB_KMEM)
1163 		vmem = kmem_arena;
1164 	else if (flags & UMA_SLAB_KERNEL)
1165 		vmem = kernel_arena;
1166 	else
1167 		panic("UMA: page_free used with invalid flags %x", flags);
1168 
1169 	kmem_free(vmem, (vm_offset_t)mem, size);
1170 }
1171 
1172 /*
1173  * Zero fill initializer
1174  *
1175  * Arguments/Returns follow uma_init specifications
1176  */
1177 static int
1178 zero_init(void *mem, int size, int flags)
1179 {
1180 	bzero(mem, size);
1181 	return (0);
1182 }
1183 
1184 /*
1185  * Finish creating a small uma keg.  This calculates ipers, and the keg size.
1186  *
1187  * Arguments
1188  *	keg  The zone we should initialize
1189  *
1190  * Returns
1191  *	Nothing
1192  */
1193 static void
1194 keg_small_init(uma_keg_t keg)
1195 {
1196 	u_int rsize;
1197 	u_int memused;
1198 	u_int wastedspace;
1199 	u_int shsize;
1200 	u_int slabsize;
1201 
1202 	if (keg->uk_flags & UMA_ZONE_PCPU) {
1203 		u_int ncpus = (mp_maxid + 1) ? (mp_maxid + 1) : MAXCPU;
1204 
1205 		slabsize = sizeof(struct pcpu);
1206 		keg->uk_ppera = howmany(ncpus * sizeof(struct pcpu),
1207 		    PAGE_SIZE);
1208 	} else {
1209 		slabsize = UMA_SLAB_SIZE;
1210 		keg->uk_ppera = 1;
1211 	}
1212 
1213 	/*
1214 	 * Calculate the size of each allocation (rsize) according to
1215 	 * alignment.  If the requested size is smaller than we have
1216 	 * allocation bits for we round it up.
1217 	 */
1218 	rsize = keg->uk_size;
1219 	if (rsize < slabsize / SLAB_SETSIZE)
1220 		rsize = slabsize / SLAB_SETSIZE;
1221 	if (rsize & keg->uk_align)
1222 		rsize = (rsize & ~keg->uk_align) + (keg->uk_align + 1);
1223 	keg->uk_rsize = rsize;
1224 
1225 	KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0 ||
1226 	    keg->uk_rsize < sizeof(struct pcpu),
1227 	    ("%s: size %u too large", __func__, keg->uk_rsize));
1228 
1229 	if (keg->uk_flags & UMA_ZONE_OFFPAGE)
1230 		shsize = 0;
1231 	else
1232 		shsize = sizeof(struct uma_slab);
1233 
1234 	keg->uk_ipers = (slabsize - shsize) / rsize;
1235 	KASSERT(keg->uk_ipers > 0 && keg->uk_ipers <= SLAB_SETSIZE,
1236 	    ("%s: keg->uk_ipers %u", __func__, keg->uk_ipers));
1237 
1238 	memused = keg->uk_ipers * rsize + shsize;
1239 	wastedspace = slabsize - memused;
1240 
1241 	/*
1242 	 * We can't do OFFPAGE if we're internal or if we've been
1243 	 * asked to not go to the VM for buckets.  If we do this we
1244 	 * may end up going to the VM  for slabs which we do not
1245 	 * want to do if we're UMA_ZFLAG_CACHEONLY as a result
1246 	 * of UMA_ZONE_VM, which clearly forbids it.
1247 	 */
1248 	if ((keg->uk_flags & UMA_ZFLAG_INTERNAL) ||
1249 	    (keg->uk_flags & UMA_ZFLAG_CACHEONLY))
1250 		return;
1251 
1252 	/*
1253 	 * See if using an OFFPAGE slab will limit our waste.  Only do
1254 	 * this if it permits more items per-slab.
1255 	 *
1256 	 * XXX We could try growing slabsize to limit max waste as well.
1257 	 * Historically this was not done because the VM could not
1258 	 * efficiently handle contiguous allocations.
1259 	 */
1260 	if ((wastedspace >= slabsize / UMA_MAX_WASTE) &&
1261 	    (keg->uk_ipers < (slabsize / keg->uk_rsize))) {
1262 		keg->uk_ipers = slabsize / keg->uk_rsize;
1263 		KASSERT(keg->uk_ipers > 0 && keg->uk_ipers <= SLAB_SETSIZE,
1264 		    ("%s: keg->uk_ipers %u", __func__, keg->uk_ipers));
1265 		CTR6(KTR_UMA, "UMA decided we need offpage slab headers for "
1266 		    "keg: %s(%p), calculated wastedspace = %d, "
1267 		    "maximum wasted space allowed = %d, "
1268 		    "calculated ipers = %d, "
1269 		    "new wasted space = %d\n", keg->uk_name, keg, wastedspace,
1270 		    slabsize / UMA_MAX_WASTE, keg->uk_ipers,
1271 		    slabsize - keg->uk_ipers * keg->uk_rsize);
1272 		keg->uk_flags |= UMA_ZONE_OFFPAGE;
1273 	}
1274 
1275 	if ((keg->uk_flags & UMA_ZONE_OFFPAGE) &&
1276 	    (keg->uk_flags & UMA_ZONE_VTOSLAB) == 0)
1277 		keg->uk_flags |= UMA_ZONE_HASH;
1278 }
1279 
1280 /*
1281  * Finish creating a large (> UMA_SLAB_SIZE) uma kegs.  Just give in and do
1282  * OFFPAGE for now.  When I can allow for more dynamic slab sizes this will be
1283  * more complicated.
1284  *
1285  * Arguments
1286  *	keg  The keg we should initialize
1287  *
1288  * Returns
1289  *	Nothing
1290  */
1291 static void
1292 keg_large_init(uma_keg_t keg)
1293 {
1294 	u_int shsize;
1295 
1296 	KASSERT(keg != NULL, ("Keg is null in keg_large_init"));
1297 	KASSERT((keg->uk_flags & UMA_ZFLAG_CACHEONLY) == 0,
1298 	    ("keg_large_init: Cannot large-init a UMA_ZFLAG_CACHEONLY keg"));
1299 	KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0,
1300 	    ("%s: Cannot large-init a UMA_ZONE_PCPU keg", __func__));
1301 
1302 	keg->uk_ppera = howmany(keg->uk_size, PAGE_SIZE);
1303 	keg->uk_ipers = 1;
1304 	keg->uk_rsize = keg->uk_size;
1305 
1306 	/* Check whether we have enough space to not do OFFPAGE. */
1307 	if ((keg->uk_flags & UMA_ZONE_OFFPAGE) == 0) {
1308 		shsize = sizeof(struct uma_slab);
1309 		if (shsize & UMA_ALIGN_PTR)
1310 			shsize = (shsize & ~UMA_ALIGN_PTR) +
1311 			    (UMA_ALIGN_PTR + 1);
1312 
1313 		if (PAGE_SIZE * keg->uk_ppera - keg->uk_rsize < shsize) {
1314 			/*
1315 			 * We can't do OFFPAGE if we're internal, in which case
1316 			 * we need an extra page per allocation to contain the
1317 			 * slab header.
1318 			 */
1319 			if ((keg->uk_flags & UMA_ZFLAG_INTERNAL) == 0)
1320 				keg->uk_flags |= UMA_ZONE_OFFPAGE;
1321 			else
1322 				keg->uk_ppera++;
1323 		}
1324 	}
1325 
1326 	if ((keg->uk_flags & UMA_ZONE_OFFPAGE) &&
1327 	    (keg->uk_flags & UMA_ZONE_VTOSLAB) == 0)
1328 		keg->uk_flags |= UMA_ZONE_HASH;
1329 }
1330 
1331 static void
1332 keg_cachespread_init(uma_keg_t keg)
1333 {
1334 	int alignsize;
1335 	int trailer;
1336 	int pages;
1337 	int rsize;
1338 
1339 	KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0,
1340 	    ("%s: Cannot cachespread-init a UMA_ZONE_PCPU keg", __func__));
1341 
1342 	alignsize = keg->uk_align + 1;
1343 	rsize = keg->uk_size;
1344 	/*
1345 	 * We want one item to start on every align boundary in a page.  To
1346 	 * do this we will span pages.  We will also extend the item by the
1347 	 * size of align if it is an even multiple of align.  Otherwise, it
1348 	 * would fall on the same boundary every time.
1349 	 */
1350 	if (rsize & keg->uk_align)
1351 		rsize = (rsize & ~keg->uk_align) + alignsize;
1352 	if ((rsize & alignsize) == 0)
1353 		rsize += alignsize;
1354 	trailer = rsize - keg->uk_size;
1355 	pages = (rsize * (PAGE_SIZE / alignsize)) / PAGE_SIZE;
1356 	pages = MIN(pages, (128 * 1024) / PAGE_SIZE);
1357 	keg->uk_rsize = rsize;
1358 	keg->uk_ppera = pages;
1359 	keg->uk_ipers = ((pages * PAGE_SIZE) + trailer) / rsize;
1360 	keg->uk_flags |= UMA_ZONE_OFFPAGE | UMA_ZONE_VTOSLAB;
1361 	KASSERT(keg->uk_ipers <= SLAB_SETSIZE,
1362 	    ("%s: keg->uk_ipers too high(%d) increase max_ipers", __func__,
1363 	    keg->uk_ipers));
1364 }
1365 
1366 /*
1367  * Keg header ctor.  This initializes all fields, locks, etc.  And inserts
1368  * the keg onto the global keg list.
1369  *
1370  * Arguments/Returns follow uma_ctor specifications
1371  *	udata  Actually uma_kctor_args
1372  */
1373 static int
1374 keg_ctor(void *mem, int size, void *udata, int flags)
1375 {
1376 	struct uma_kctor_args *arg = udata;
1377 	uma_keg_t keg = mem;
1378 	uma_zone_t zone;
1379 
1380 	bzero(keg, size);
1381 	keg->uk_size = arg->size;
1382 	keg->uk_init = arg->uminit;
1383 	keg->uk_fini = arg->fini;
1384 	keg->uk_align = arg->align;
1385 	keg->uk_free = 0;
1386 	keg->uk_reserve = 0;
1387 	keg->uk_pages = 0;
1388 	keg->uk_flags = arg->flags;
1389 	keg->uk_slabzone = NULL;
1390 
1391 	/*
1392 	 * The master zone is passed to us at keg-creation time.
1393 	 */
1394 	zone = arg->zone;
1395 	keg->uk_name = zone->uz_name;
1396 
1397 	if (arg->flags & UMA_ZONE_VM)
1398 		keg->uk_flags |= UMA_ZFLAG_CACHEONLY;
1399 
1400 	if (arg->flags & UMA_ZONE_ZINIT)
1401 		keg->uk_init = zero_init;
1402 
1403 	if (arg->flags & UMA_ZONE_MALLOC)
1404 		keg->uk_flags |= UMA_ZONE_VTOSLAB;
1405 
1406 	if (arg->flags & UMA_ZONE_PCPU)
1407 #ifdef SMP
1408 		keg->uk_flags |= UMA_ZONE_OFFPAGE;
1409 #else
1410 		keg->uk_flags &= ~UMA_ZONE_PCPU;
1411 #endif
1412 
1413 	if (keg->uk_flags & UMA_ZONE_CACHESPREAD) {
1414 		keg_cachespread_init(keg);
1415 	} else {
1416 		if (keg->uk_size > (UMA_SLAB_SIZE - sizeof(struct uma_slab)))
1417 			keg_large_init(keg);
1418 		else
1419 			keg_small_init(keg);
1420 	}
1421 
1422 	if (keg->uk_flags & UMA_ZONE_OFFPAGE)
1423 		keg->uk_slabzone = slabzone;
1424 
1425 	/*
1426 	 * If we haven't booted yet we need allocations to go through the
1427 	 * startup cache until the vm is ready.
1428 	 */
1429 	if (booted < UMA_STARTUP2)
1430 		keg->uk_allocf = startup_alloc;
1431 #ifdef UMA_MD_SMALL_ALLOC
1432 	else if (keg->uk_ppera == 1)
1433 		keg->uk_allocf = uma_small_alloc;
1434 #endif
1435 	else
1436 		keg->uk_allocf = page_alloc;
1437 #ifdef UMA_MD_SMALL_ALLOC
1438 	if (keg->uk_ppera == 1)
1439 		keg->uk_freef = uma_small_free;
1440 	else
1441 #endif
1442 		keg->uk_freef = page_free;
1443 
1444 	/*
1445 	 * Initialize keg's lock
1446 	 */
1447 	KEG_LOCK_INIT(keg, (arg->flags & UMA_ZONE_MTXCLASS));
1448 
1449 	/*
1450 	 * If we're putting the slab header in the actual page we need to
1451 	 * figure out where in each page it goes.  This calculates a right
1452 	 * justified offset into the memory on an ALIGN_PTR boundary.
1453 	 */
1454 	if (!(keg->uk_flags & UMA_ZONE_OFFPAGE)) {
1455 		u_int totsize;
1456 
1457 		/* Size of the slab struct and free list */
1458 		totsize = sizeof(struct uma_slab);
1459 
1460 		if (totsize & UMA_ALIGN_PTR)
1461 			totsize = (totsize & ~UMA_ALIGN_PTR) +
1462 			    (UMA_ALIGN_PTR + 1);
1463 		keg->uk_pgoff = (PAGE_SIZE * keg->uk_ppera) - totsize;
1464 
1465 		/*
1466 		 * The only way the following is possible is if with our
1467 		 * UMA_ALIGN_PTR adjustments we are now bigger than
1468 		 * UMA_SLAB_SIZE.  I haven't checked whether this is
1469 		 * mathematically possible for all cases, so we make
1470 		 * sure here anyway.
1471 		 */
1472 		totsize = keg->uk_pgoff + sizeof(struct uma_slab);
1473 		if (totsize > PAGE_SIZE * keg->uk_ppera) {
1474 			printf("zone %s ipers %d rsize %d size %d\n",
1475 			    zone->uz_name, keg->uk_ipers, keg->uk_rsize,
1476 			    keg->uk_size);
1477 			panic("UMA slab won't fit.");
1478 		}
1479 	}
1480 
1481 	if (keg->uk_flags & UMA_ZONE_HASH)
1482 		hash_alloc(&keg->uk_hash);
1483 
1484 	CTR5(KTR_UMA, "keg_ctor %p zone %s(%p) out %d free %d\n",
1485 	    keg, zone->uz_name, zone,
1486 	    (keg->uk_pages / keg->uk_ppera) * keg->uk_ipers - keg->uk_free,
1487 	    keg->uk_free);
1488 
1489 	LIST_INSERT_HEAD(&keg->uk_zones, zone, uz_link);
1490 
1491 	rw_wlock(&uma_rwlock);
1492 	LIST_INSERT_HEAD(&uma_kegs, keg, uk_link);
1493 	rw_wunlock(&uma_rwlock);
1494 	return (0);
1495 }
1496 
1497 /*
1498  * Zone header ctor.  This initializes all fields, locks, etc.
1499  *
1500  * Arguments/Returns follow uma_ctor specifications
1501  *	udata  Actually uma_zctor_args
1502  */
1503 static int
1504 zone_ctor(void *mem, int size, void *udata, int flags)
1505 {
1506 	struct uma_zctor_args *arg = udata;
1507 	uma_zone_t zone = mem;
1508 	uma_zone_t z;
1509 	uma_keg_t keg;
1510 
1511 	bzero(zone, size);
1512 	zone->uz_name = arg->name;
1513 	zone->uz_ctor = arg->ctor;
1514 	zone->uz_dtor = arg->dtor;
1515 	zone->uz_slab = zone_fetch_slab;
1516 	zone->uz_init = NULL;
1517 	zone->uz_fini = NULL;
1518 	zone->uz_allocs = 0;
1519 	zone->uz_frees = 0;
1520 	zone->uz_fails = 0;
1521 	zone->uz_sleeps = 0;
1522 	zone->uz_count = 0;
1523 	zone->uz_count_min = 0;
1524 	zone->uz_flags = 0;
1525 	zone->uz_warning = NULL;
1526 	timevalclear(&zone->uz_ratecheck);
1527 	keg = arg->keg;
1528 
1529 	ZONE_LOCK_INIT(zone, (arg->flags & UMA_ZONE_MTXCLASS));
1530 
1531 	/*
1532 	 * This is a pure cache zone, no kegs.
1533 	 */
1534 	if (arg->import) {
1535 		if (arg->flags & UMA_ZONE_VM)
1536 			arg->flags |= UMA_ZFLAG_CACHEONLY;
1537 		zone->uz_flags = arg->flags;
1538 		zone->uz_size = arg->size;
1539 		zone->uz_import = arg->import;
1540 		zone->uz_release = arg->release;
1541 		zone->uz_arg = arg->arg;
1542 		zone->uz_lockptr = &zone->uz_lock;
1543 		rw_wlock(&uma_rwlock);
1544 		LIST_INSERT_HEAD(&uma_cachezones, zone, uz_link);
1545 		rw_wunlock(&uma_rwlock);
1546 		goto out;
1547 	}
1548 
1549 	/*
1550 	 * Use the regular zone/keg/slab allocator.
1551 	 */
1552 	zone->uz_import = (uma_import)zone_import;
1553 	zone->uz_release = (uma_release)zone_release;
1554 	zone->uz_arg = zone;
1555 
1556 	if (arg->flags & UMA_ZONE_SECONDARY) {
1557 		KASSERT(arg->keg != NULL, ("Secondary zone on zero'd keg"));
1558 		zone->uz_init = arg->uminit;
1559 		zone->uz_fini = arg->fini;
1560 		zone->uz_lockptr = &keg->uk_lock;
1561 		zone->uz_flags |= UMA_ZONE_SECONDARY;
1562 		rw_wlock(&uma_rwlock);
1563 		ZONE_LOCK(zone);
1564 		LIST_FOREACH(z, &keg->uk_zones, uz_link) {
1565 			if (LIST_NEXT(z, uz_link) == NULL) {
1566 				LIST_INSERT_AFTER(z, zone, uz_link);
1567 				break;
1568 			}
1569 		}
1570 		ZONE_UNLOCK(zone);
1571 		rw_wunlock(&uma_rwlock);
1572 	} else if (keg == NULL) {
1573 		if ((keg = uma_kcreate(zone, arg->size, arg->uminit, arg->fini,
1574 		    arg->align, arg->flags)) == NULL)
1575 			return (ENOMEM);
1576 	} else {
1577 		struct uma_kctor_args karg;
1578 		int error;
1579 
1580 		/* We should only be here from uma_startup() */
1581 		karg.size = arg->size;
1582 		karg.uminit = arg->uminit;
1583 		karg.fini = arg->fini;
1584 		karg.align = arg->align;
1585 		karg.flags = arg->flags;
1586 		karg.zone = zone;
1587 		error = keg_ctor(arg->keg, sizeof(struct uma_keg), &karg,
1588 		    flags);
1589 		if (error)
1590 			return (error);
1591 	}
1592 
1593 	/*
1594 	 * Link in the first keg.
1595 	 */
1596 	zone->uz_klink.kl_keg = keg;
1597 	LIST_INSERT_HEAD(&zone->uz_kegs, &zone->uz_klink, kl_link);
1598 	zone->uz_lockptr = &keg->uk_lock;
1599 	zone->uz_size = keg->uk_size;
1600 	zone->uz_flags |= (keg->uk_flags &
1601 	    (UMA_ZONE_INHERIT | UMA_ZFLAG_INHERIT));
1602 
1603 	/*
1604 	 * Some internal zones don't have room allocated for the per cpu
1605 	 * caches.  If we're internal, bail out here.
1606 	 */
1607 	if (keg->uk_flags & UMA_ZFLAG_INTERNAL) {
1608 		KASSERT((zone->uz_flags & UMA_ZONE_SECONDARY) == 0,
1609 		    ("Secondary zone requested UMA_ZFLAG_INTERNAL"));
1610 		return (0);
1611 	}
1612 
1613 out:
1614 	if ((arg->flags & UMA_ZONE_MAXBUCKET) == 0)
1615 		zone->uz_count = bucket_select(zone->uz_size);
1616 	else
1617 		zone->uz_count = BUCKET_MAX;
1618 	zone->uz_count_min = zone->uz_count;
1619 
1620 	return (0);
1621 }
1622 
1623 /*
1624  * Keg header dtor.  This frees all data, destroys locks, frees the hash
1625  * table and removes the keg from the global list.
1626  *
1627  * Arguments/Returns follow uma_dtor specifications
1628  *	udata  unused
1629  */
1630 static void
1631 keg_dtor(void *arg, int size, void *udata)
1632 {
1633 	uma_keg_t keg;
1634 
1635 	keg = (uma_keg_t)arg;
1636 	KEG_LOCK(keg);
1637 	if (keg->uk_free != 0) {
1638 		printf("Freed UMA keg (%s) was not empty (%d items). "
1639 		    " Lost %d pages of memory.\n",
1640 		    keg->uk_name ? keg->uk_name : "",
1641 		    keg->uk_free, keg->uk_pages);
1642 	}
1643 	KEG_UNLOCK(keg);
1644 
1645 	hash_free(&keg->uk_hash);
1646 
1647 	KEG_LOCK_FINI(keg);
1648 }
1649 
1650 /*
1651  * Zone header dtor.
1652  *
1653  * Arguments/Returns follow uma_dtor specifications
1654  *	udata  unused
1655  */
1656 static void
1657 zone_dtor(void *arg, int size, void *udata)
1658 {
1659 	uma_klink_t klink;
1660 	uma_zone_t zone;
1661 	uma_keg_t keg;
1662 
1663 	zone = (uma_zone_t)arg;
1664 	keg = zone_first_keg(zone);
1665 
1666 	if (!(zone->uz_flags & UMA_ZFLAG_INTERNAL))
1667 		cache_drain(zone);
1668 
1669 	rw_wlock(&uma_rwlock);
1670 	LIST_REMOVE(zone, uz_link);
1671 	rw_wunlock(&uma_rwlock);
1672 	/*
1673 	 * XXX there are some races here where
1674 	 * the zone can be drained but zone lock
1675 	 * released and then refilled before we
1676 	 * remove it... we dont care for now
1677 	 */
1678 	zone_drain_wait(zone, M_WAITOK);
1679 	/*
1680 	 * Unlink all of our kegs.
1681 	 */
1682 	while ((klink = LIST_FIRST(&zone->uz_kegs)) != NULL) {
1683 		klink->kl_keg = NULL;
1684 		LIST_REMOVE(klink, kl_link);
1685 		if (klink == &zone->uz_klink)
1686 			continue;
1687 		free(klink, M_TEMP);
1688 	}
1689 	/*
1690 	 * We only destroy kegs from non secondary zones.
1691 	 */
1692 	if (keg != NULL && (zone->uz_flags & UMA_ZONE_SECONDARY) == 0)  {
1693 		rw_wlock(&uma_rwlock);
1694 		LIST_REMOVE(keg, uk_link);
1695 		rw_wunlock(&uma_rwlock);
1696 		zone_free_item(kegs, keg, NULL, SKIP_NONE);
1697 	}
1698 	ZONE_LOCK_FINI(zone);
1699 }
1700 
1701 /*
1702  * Traverses every zone in the system and calls a callback
1703  *
1704  * Arguments:
1705  *	zfunc  A pointer to a function which accepts a zone
1706  *		as an argument.
1707  *
1708  * Returns:
1709  *	Nothing
1710  */
1711 static void
1712 zone_foreach(void (*zfunc)(uma_zone_t))
1713 {
1714 	uma_keg_t keg;
1715 	uma_zone_t zone;
1716 
1717 	rw_rlock(&uma_rwlock);
1718 	LIST_FOREACH(keg, &uma_kegs, uk_link) {
1719 		LIST_FOREACH(zone, &keg->uk_zones, uz_link)
1720 			zfunc(zone);
1721 	}
1722 	rw_runlock(&uma_rwlock);
1723 }
1724 
1725 /* Public functions */
1726 /* See uma.h */
1727 void
1728 uma_startup(void *mem, int npages)
1729 {
1730 	struct uma_zctor_args args;
1731 
1732 	rw_init(&uma_rwlock, "UMA lock");
1733 
1734 	/* "manually" create the initial zone */
1735 	memset(&args, 0, sizeof(args));
1736 	args.name = "UMA Kegs";
1737 	args.size = sizeof(struct uma_keg);
1738 	args.ctor = keg_ctor;
1739 	args.dtor = keg_dtor;
1740 	args.uminit = zero_init;
1741 	args.fini = NULL;
1742 	args.keg = &masterkeg;
1743 	args.align = 32 - 1;
1744 	args.flags = UMA_ZFLAG_INTERNAL;
1745 	/* The initial zone has no Per cpu queues so it's smaller */
1746 	zone_ctor(kegs, sizeof(struct uma_zone), &args, M_WAITOK);
1747 
1748 	mtx_init(&uma_boot_pages_mtx, "UMA boot pages", NULL, MTX_DEF);
1749 	bootmem = mem;
1750 	boot_pages = npages;
1751 
1752 	args.name = "UMA Zones";
1753 	args.size = sizeof(struct uma_zone) +
1754 	    (sizeof(struct uma_cache) * (mp_maxid + 1));
1755 	args.ctor = zone_ctor;
1756 	args.dtor = zone_dtor;
1757 	args.uminit = zero_init;
1758 	args.fini = NULL;
1759 	args.keg = NULL;
1760 	args.align = 32 - 1;
1761 	args.flags = UMA_ZFLAG_INTERNAL;
1762 	/* The initial zone has no Per cpu queues so it's smaller */
1763 	zone_ctor(zones, sizeof(struct uma_zone), &args, M_WAITOK);
1764 
1765 	/* Now make a zone for slab headers */
1766 	slabzone = uma_zcreate("UMA Slabs",
1767 				sizeof(struct uma_slab),
1768 				NULL, NULL, NULL, NULL,
1769 				UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
1770 
1771 	hashzone = uma_zcreate("UMA Hash",
1772 	    sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT,
1773 	    NULL, NULL, NULL, NULL,
1774 	    UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
1775 
1776 	bucket_init();
1777 
1778 	booted = UMA_STARTUP;
1779 }
1780 
1781 /* see uma.h */
1782 void
1783 uma_startup2(void)
1784 {
1785 	booted = UMA_STARTUP2;
1786 	bucket_enable();
1787 	sx_init(&uma_drain_lock, "umadrain");
1788 }
1789 
1790 /*
1791  * Initialize our callout handle
1792  *
1793  */
1794 
1795 static void
1796 uma_startup3(void)
1797 {
1798 
1799 	callout_init(&uma_callout, 1);
1800 	callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
1801 }
1802 
1803 static uma_keg_t
1804 uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini,
1805 		int align, uint32_t flags)
1806 {
1807 	struct uma_kctor_args args;
1808 
1809 	args.size = size;
1810 	args.uminit = uminit;
1811 	args.fini = fini;
1812 	args.align = (align == UMA_ALIGN_CACHE) ? uma_align_cache : align;
1813 	args.flags = flags;
1814 	args.zone = zone;
1815 	return (zone_alloc_item(kegs, &args, M_WAITOK));
1816 }
1817 
1818 /* See uma.h */
1819 void
1820 uma_set_align(int align)
1821 {
1822 
1823 	if (align != UMA_ALIGN_CACHE)
1824 		uma_align_cache = align;
1825 }
1826 
1827 /* See uma.h */
1828 uma_zone_t
1829 uma_zcreate(const char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
1830 		uma_init uminit, uma_fini fini, int align, uint32_t flags)
1831 
1832 {
1833 	struct uma_zctor_args args;
1834 	uma_zone_t res;
1835 	bool locked;
1836 
1837 	KASSERT(powerof2(align + 1), ("invalid zone alignment %d for \"%s\"",
1838 	    align, name));
1839 
1840 	/* This stuff is essential for the zone ctor */
1841 	memset(&args, 0, sizeof(args));
1842 	args.name = name;
1843 	args.size = size;
1844 	args.ctor = ctor;
1845 	args.dtor = dtor;
1846 	args.uminit = uminit;
1847 	args.fini = fini;
1848 #ifdef  INVARIANTS
1849 	/*
1850 	 * If a zone is being created with an empty constructor and
1851 	 * destructor, pass UMA constructor/destructor which checks for
1852 	 * memory use after free.
1853 	 */
1854 	if ((!(flags & (UMA_ZONE_ZINIT | UMA_ZONE_NOFREE))) &&
1855 	    ctor == NULL && dtor == NULL && uminit == NULL && fini == NULL) {
1856 		args.ctor = trash_ctor;
1857 		args.dtor = trash_dtor;
1858 		args.uminit = trash_init;
1859 		args.fini = trash_fini;
1860 	}
1861 #endif
1862 	args.align = align;
1863 	args.flags = flags;
1864 	args.keg = NULL;
1865 
1866 	if (booted < UMA_STARTUP2) {
1867 		locked = false;
1868 	} else {
1869 		sx_slock(&uma_drain_lock);
1870 		locked = true;
1871 	}
1872 	res = zone_alloc_item(zones, &args, M_WAITOK);
1873 	if (locked)
1874 		sx_sunlock(&uma_drain_lock);
1875 	return (res);
1876 }
1877 
1878 /* See uma.h */
1879 uma_zone_t
1880 uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
1881 		    uma_init zinit, uma_fini zfini, uma_zone_t master)
1882 {
1883 	struct uma_zctor_args args;
1884 	uma_keg_t keg;
1885 	uma_zone_t res;
1886 	bool locked;
1887 
1888 	keg = zone_first_keg(master);
1889 	memset(&args, 0, sizeof(args));
1890 	args.name = name;
1891 	args.size = keg->uk_size;
1892 	args.ctor = ctor;
1893 	args.dtor = dtor;
1894 	args.uminit = zinit;
1895 	args.fini = zfini;
1896 	args.align = keg->uk_align;
1897 	args.flags = keg->uk_flags | UMA_ZONE_SECONDARY;
1898 	args.keg = keg;
1899 
1900 	if (booted < UMA_STARTUP2) {
1901 		locked = false;
1902 	} else {
1903 		sx_slock(&uma_drain_lock);
1904 		locked = true;
1905 	}
1906 	/* XXX Attaches only one keg of potentially many. */
1907 	res = zone_alloc_item(zones, &args, M_WAITOK);
1908 	if (locked)
1909 		sx_sunlock(&uma_drain_lock);
1910 	return (res);
1911 }
1912 
1913 /* See uma.h */
1914 uma_zone_t
1915 uma_zcache_create(char *name, int size, uma_ctor ctor, uma_dtor dtor,
1916 		    uma_init zinit, uma_fini zfini, uma_import zimport,
1917 		    uma_release zrelease, void *arg, int flags)
1918 {
1919 	struct uma_zctor_args args;
1920 
1921 	memset(&args, 0, sizeof(args));
1922 	args.name = name;
1923 	args.size = size;
1924 	args.ctor = ctor;
1925 	args.dtor = dtor;
1926 	args.uminit = zinit;
1927 	args.fini = zfini;
1928 	args.import = zimport;
1929 	args.release = zrelease;
1930 	args.arg = arg;
1931 	args.align = 0;
1932 	args.flags = flags;
1933 
1934 	return (zone_alloc_item(zones, &args, M_WAITOK));
1935 }
1936 
1937 static void
1938 zone_lock_pair(uma_zone_t a, uma_zone_t b)
1939 {
1940 	if (a < b) {
1941 		ZONE_LOCK(a);
1942 		mtx_lock_flags(b->uz_lockptr, MTX_DUPOK);
1943 	} else {
1944 		ZONE_LOCK(b);
1945 		mtx_lock_flags(a->uz_lockptr, MTX_DUPOK);
1946 	}
1947 }
1948 
1949 static void
1950 zone_unlock_pair(uma_zone_t a, uma_zone_t b)
1951 {
1952 
1953 	ZONE_UNLOCK(a);
1954 	ZONE_UNLOCK(b);
1955 }
1956 
1957 int
1958 uma_zsecond_add(uma_zone_t zone, uma_zone_t master)
1959 {
1960 	uma_klink_t klink;
1961 	uma_klink_t kl;
1962 	int error;
1963 
1964 	error = 0;
1965 	klink = malloc(sizeof(*klink), M_TEMP, M_WAITOK | M_ZERO);
1966 
1967 	zone_lock_pair(zone, master);
1968 	/*
1969 	 * zone must use vtoslab() to resolve objects and must already be
1970 	 * a secondary.
1971 	 */
1972 	if ((zone->uz_flags & (UMA_ZONE_VTOSLAB | UMA_ZONE_SECONDARY))
1973 	    != (UMA_ZONE_VTOSLAB | UMA_ZONE_SECONDARY)) {
1974 		error = EINVAL;
1975 		goto out;
1976 	}
1977 	/*
1978 	 * The new master must also use vtoslab().
1979 	 */
1980 	if ((zone->uz_flags & UMA_ZONE_VTOSLAB) != UMA_ZONE_VTOSLAB) {
1981 		error = EINVAL;
1982 		goto out;
1983 	}
1984 
1985 	/*
1986 	 * The underlying object must be the same size.  rsize
1987 	 * may be different.
1988 	 */
1989 	if (master->uz_size != zone->uz_size) {
1990 		error = E2BIG;
1991 		goto out;
1992 	}
1993 	/*
1994 	 * Put it at the end of the list.
1995 	 */
1996 	klink->kl_keg = zone_first_keg(master);
1997 	LIST_FOREACH(kl, &zone->uz_kegs, kl_link) {
1998 		if (LIST_NEXT(kl, kl_link) == NULL) {
1999 			LIST_INSERT_AFTER(kl, klink, kl_link);
2000 			break;
2001 		}
2002 	}
2003 	klink = NULL;
2004 	zone->uz_flags |= UMA_ZFLAG_MULTI;
2005 	zone->uz_slab = zone_fetch_slab_multi;
2006 
2007 out:
2008 	zone_unlock_pair(zone, master);
2009 	if (klink != NULL)
2010 		free(klink, M_TEMP);
2011 
2012 	return (error);
2013 }
2014 
2015 
2016 /* See uma.h */
2017 void
2018 uma_zdestroy(uma_zone_t zone)
2019 {
2020 
2021 	sx_slock(&uma_drain_lock);
2022 	zone_free_item(zones, zone, NULL, SKIP_NONE);
2023 	sx_sunlock(&uma_drain_lock);
2024 }
2025 
2026 void
2027 uma_zwait(uma_zone_t zone)
2028 {
2029 	void *item;
2030 
2031 	item = uma_zalloc_arg(zone, NULL, M_WAITOK);
2032 	uma_zfree(zone, item);
2033 }
2034 
2035 /* See uma.h */
2036 void *
2037 uma_zalloc_arg(uma_zone_t zone, void *udata, int flags)
2038 {
2039 	void *item;
2040 	uma_cache_t cache;
2041 	uma_bucket_t bucket;
2042 	int lockfail;
2043 	int cpu;
2044 
2045 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
2046 	random_harvest_fast_uma(&zone, sizeof(zone), 1, RANDOM_UMA);
2047 
2048 	/* This is the fast path allocation */
2049 	CTR4(KTR_UMA, "uma_zalloc_arg thread %x zone %s(%p) flags %d",
2050 	    curthread, zone->uz_name, zone, flags);
2051 
2052 	if (flags & M_WAITOK) {
2053 		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
2054 		    "uma_zalloc_arg: zone \"%s\"", zone->uz_name);
2055 	}
2056 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
2057 	    ("uma_zalloc_arg: called with spinlock or critical section held"));
2058 
2059 #ifdef DEBUG_MEMGUARD
2060 	if (memguard_cmp_zone(zone)) {
2061 		item = memguard_alloc(zone->uz_size, flags);
2062 		if (item != NULL) {
2063 			if (zone->uz_init != NULL &&
2064 			    zone->uz_init(item, zone->uz_size, flags) != 0)
2065 				return (NULL);
2066 			if (zone->uz_ctor != NULL &&
2067 			    zone->uz_ctor(item, zone->uz_size, udata,
2068 			    flags) != 0) {
2069 			    	zone->uz_fini(item, zone->uz_size);
2070 				return (NULL);
2071 			}
2072 			return (item);
2073 		}
2074 		/* This is unfortunate but should not be fatal. */
2075 	}
2076 #endif
2077 	/*
2078 	 * If possible, allocate from the per-CPU cache.  There are two
2079 	 * requirements for safe access to the per-CPU cache: (1) the thread
2080 	 * accessing the cache must not be preempted or yield during access,
2081 	 * and (2) the thread must not migrate CPUs without switching which
2082 	 * cache it accesses.  We rely on a critical section to prevent
2083 	 * preemption and migration.  We release the critical section in
2084 	 * order to acquire the zone mutex if we are unable to allocate from
2085 	 * the current cache; when we re-acquire the critical section, we
2086 	 * must detect and handle migration if it has occurred.
2087 	 */
2088 	critical_enter();
2089 	cpu = curcpu;
2090 	cache = &zone->uz_cpu[cpu];
2091 
2092 zalloc_start:
2093 	bucket = cache->uc_allocbucket;
2094 	if (bucket != NULL && bucket->ub_cnt > 0) {
2095 		bucket->ub_cnt--;
2096 		item = bucket->ub_bucket[bucket->ub_cnt];
2097 #ifdef INVARIANTS
2098 		bucket->ub_bucket[bucket->ub_cnt] = NULL;
2099 #endif
2100 		KASSERT(item != NULL, ("uma_zalloc: Bucket pointer mangled."));
2101 		cache->uc_allocs++;
2102 		critical_exit();
2103 		if (zone->uz_ctor != NULL &&
2104 		    zone->uz_ctor(item, zone->uz_size, udata, flags) != 0) {
2105 			atomic_add_long(&zone->uz_fails, 1);
2106 			zone_free_item(zone, item, udata, SKIP_DTOR);
2107 			return (NULL);
2108 		}
2109 #ifdef INVARIANTS
2110 		uma_dbg_alloc(zone, NULL, item);
2111 #endif
2112 		if (flags & M_ZERO)
2113 			uma_zero_item(item, zone);
2114 		return (item);
2115 	}
2116 
2117 	/*
2118 	 * We have run out of items in our alloc bucket.
2119 	 * See if we can switch with our free bucket.
2120 	 */
2121 	bucket = cache->uc_freebucket;
2122 	if (bucket != NULL && bucket->ub_cnt > 0) {
2123 		CTR2(KTR_UMA,
2124 		    "uma_zalloc: zone %s(%p) swapping empty with alloc",
2125 		    zone->uz_name, zone);
2126 		cache->uc_freebucket = cache->uc_allocbucket;
2127 		cache->uc_allocbucket = bucket;
2128 		goto zalloc_start;
2129 	}
2130 
2131 	/*
2132 	 * Discard any empty allocation bucket while we hold no locks.
2133 	 */
2134 	bucket = cache->uc_allocbucket;
2135 	cache->uc_allocbucket = NULL;
2136 	critical_exit();
2137 	if (bucket != NULL)
2138 		bucket_free(zone, bucket, udata);
2139 
2140 	/* Short-circuit for zones without buckets and low memory. */
2141 	if (zone->uz_count == 0 || bucketdisable)
2142 		goto zalloc_item;
2143 
2144 	/*
2145 	 * Attempt to retrieve the item from the per-CPU cache has failed, so
2146 	 * we must go back to the zone.  This requires the zone lock, so we
2147 	 * must drop the critical section, then re-acquire it when we go back
2148 	 * to the cache.  Since the critical section is released, we may be
2149 	 * preempted or migrate.  As such, make sure not to maintain any
2150 	 * thread-local state specific to the cache from prior to releasing
2151 	 * the critical section.
2152 	 */
2153 	lockfail = 0;
2154 	if (ZONE_TRYLOCK(zone) == 0) {
2155 		/* Record contention to size the buckets. */
2156 		ZONE_LOCK(zone);
2157 		lockfail = 1;
2158 	}
2159 	critical_enter();
2160 	cpu = curcpu;
2161 	cache = &zone->uz_cpu[cpu];
2162 
2163 	/*
2164 	 * Since we have locked the zone we may as well send back our stats.
2165 	 */
2166 	atomic_add_long(&zone->uz_allocs, cache->uc_allocs);
2167 	atomic_add_long(&zone->uz_frees, cache->uc_frees);
2168 	cache->uc_allocs = 0;
2169 	cache->uc_frees = 0;
2170 
2171 	/* See if we lost the race to fill the cache. */
2172 	if (cache->uc_allocbucket != NULL) {
2173 		ZONE_UNLOCK(zone);
2174 		goto zalloc_start;
2175 	}
2176 
2177 	/*
2178 	 * Check the zone's cache of buckets.
2179 	 */
2180 	if ((bucket = LIST_FIRST(&zone->uz_buckets)) != NULL) {
2181 		KASSERT(bucket->ub_cnt != 0,
2182 		    ("uma_zalloc_arg: Returning an empty bucket."));
2183 
2184 		LIST_REMOVE(bucket, ub_link);
2185 		cache->uc_allocbucket = bucket;
2186 		ZONE_UNLOCK(zone);
2187 		goto zalloc_start;
2188 	}
2189 	/* We are no longer associated with this CPU. */
2190 	critical_exit();
2191 
2192 	/*
2193 	 * We bump the uz count when the cache size is insufficient to
2194 	 * handle the working set.
2195 	 */
2196 	if (lockfail && zone->uz_count < BUCKET_MAX)
2197 		zone->uz_count++;
2198 	ZONE_UNLOCK(zone);
2199 
2200 	/*
2201 	 * Now lets just fill a bucket and put it on the free list.  If that
2202 	 * works we'll restart the allocation from the beginning and it
2203 	 * will use the just filled bucket.
2204 	 */
2205 	bucket = zone_alloc_bucket(zone, udata, flags);
2206 	CTR3(KTR_UMA, "uma_zalloc: zone %s(%p) bucket zone returned %p",
2207 	    zone->uz_name, zone, bucket);
2208 	if (bucket != NULL) {
2209 		ZONE_LOCK(zone);
2210 		critical_enter();
2211 		cpu = curcpu;
2212 		cache = &zone->uz_cpu[cpu];
2213 		/*
2214 		 * See if we lost the race or were migrated.  Cache the
2215 		 * initialized bucket to make this less likely or claim
2216 		 * the memory directly.
2217 		 */
2218 		if (cache->uc_allocbucket == NULL)
2219 			cache->uc_allocbucket = bucket;
2220 		else
2221 			LIST_INSERT_HEAD(&zone->uz_buckets, bucket, ub_link);
2222 		ZONE_UNLOCK(zone);
2223 		goto zalloc_start;
2224 	}
2225 
2226 	/*
2227 	 * We may not be able to get a bucket so return an actual item.
2228 	 */
2229 zalloc_item:
2230 	item = zone_alloc_item(zone, udata, flags);
2231 
2232 	return (item);
2233 }
2234 
2235 static uma_slab_t
2236 keg_fetch_slab(uma_keg_t keg, uma_zone_t zone, int flags)
2237 {
2238 	uma_slab_t slab;
2239 	int reserve;
2240 
2241 	mtx_assert(&keg->uk_lock, MA_OWNED);
2242 	slab = NULL;
2243 	reserve = 0;
2244 	if ((flags & M_USE_RESERVE) == 0)
2245 		reserve = keg->uk_reserve;
2246 
2247 	for (;;) {
2248 		/*
2249 		 * Find a slab with some space.  Prefer slabs that are partially
2250 		 * used over those that are totally full.  This helps to reduce
2251 		 * fragmentation.
2252 		 */
2253 		if (keg->uk_free > reserve) {
2254 			if (!LIST_EMPTY(&keg->uk_part_slab)) {
2255 				slab = LIST_FIRST(&keg->uk_part_slab);
2256 			} else {
2257 				slab = LIST_FIRST(&keg->uk_free_slab);
2258 				LIST_REMOVE(slab, us_link);
2259 				LIST_INSERT_HEAD(&keg->uk_part_slab, slab,
2260 				    us_link);
2261 			}
2262 			MPASS(slab->us_keg == keg);
2263 			return (slab);
2264 		}
2265 
2266 		/*
2267 		 * M_NOVM means don't ask at all!
2268 		 */
2269 		if (flags & M_NOVM)
2270 			break;
2271 
2272 		if (keg->uk_maxpages && keg->uk_pages >= keg->uk_maxpages) {
2273 			keg->uk_flags |= UMA_ZFLAG_FULL;
2274 			/*
2275 			 * If this is not a multi-zone, set the FULL bit.
2276 			 * Otherwise slab_multi() takes care of it.
2277 			 */
2278 			if ((zone->uz_flags & UMA_ZFLAG_MULTI) == 0) {
2279 				zone->uz_flags |= UMA_ZFLAG_FULL;
2280 				zone_log_warning(zone);
2281 				zone_maxaction(zone);
2282 			}
2283 			if (flags & M_NOWAIT)
2284 				break;
2285 			zone->uz_sleeps++;
2286 			msleep(keg, &keg->uk_lock, PVM, "keglimit", 0);
2287 			continue;
2288 		}
2289 		slab = keg_alloc_slab(keg, zone, flags);
2290 		/*
2291 		 * If we got a slab here it's safe to mark it partially used
2292 		 * and return.  We assume that the caller is going to remove
2293 		 * at least one item.
2294 		 */
2295 		if (slab) {
2296 			MPASS(slab->us_keg == keg);
2297 			LIST_INSERT_HEAD(&keg->uk_part_slab, slab, us_link);
2298 			return (slab);
2299 		}
2300 		/*
2301 		 * We might not have been able to get a slab but another cpu
2302 		 * could have while we were unlocked.  Check again before we
2303 		 * fail.
2304 		 */
2305 		flags |= M_NOVM;
2306 	}
2307 	return (slab);
2308 }
2309 
2310 static uma_slab_t
2311 zone_fetch_slab(uma_zone_t zone, uma_keg_t keg, int flags)
2312 {
2313 	uma_slab_t slab;
2314 
2315 	if (keg == NULL) {
2316 		keg = zone_first_keg(zone);
2317 		KEG_LOCK(keg);
2318 	}
2319 
2320 	for (;;) {
2321 		slab = keg_fetch_slab(keg, zone, flags);
2322 		if (slab)
2323 			return (slab);
2324 		if (flags & (M_NOWAIT | M_NOVM))
2325 			break;
2326 	}
2327 	KEG_UNLOCK(keg);
2328 	return (NULL);
2329 }
2330 
2331 /*
2332  * uma_zone_fetch_slab_multi:  Fetches a slab from one available keg.  Returns
2333  * with the keg locked.  On NULL no lock is held.
2334  *
2335  * The last pointer is used to seed the search.  It is not required.
2336  */
2337 static uma_slab_t
2338 zone_fetch_slab_multi(uma_zone_t zone, uma_keg_t last, int rflags)
2339 {
2340 	uma_klink_t klink;
2341 	uma_slab_t slab;
2342 	uma_keg_t keg;
2343 	int flags;
2344 	int empty;
2345 	int full;
2346 
2347 	/*
2348 	 * Don't wait on the first pass.  This will skip limit tests
2349 	 * as well.  We don't want to block if we can find a provider
2350 	 * without blocking.
2351 	 */
2352 	flags = (rflags & ~M_WAITOK) | M_NOWAIT;
2353 	/*
2354 	 * Use the last slab allocated as a hint for where to start
2355 	 * the search.
2356 	 */
2357 	if (last != NULL) {
2358 		slab = keg_fetch_slab(last, zone, flags);
2359 		if (slab)
2360 			return (slab);
2361 		KEG_UNLOCK(last);
2362 	}
2363 	/*
2364 	 * Loop until we have a slab incase of transient failures
2365 	 * while M_WAITOK is specified.  I'm not sure this is 100%
2366 	 * required but we've done it for so long now.
2367 	 */
2368 	for (;;) {
2369 		empty = 0;
2370 		full = 0;
2371 		/*
2372 		 * Search the available kegs for slabs.  Be careful to hold the
2373 		 * correct lock while calling into the keg layer.
2374 		 */
2375 		LIST_FOREACH(klink, &zone->uz_kegs, kl_link) {
2376 			keg = klink->kl_keg;
2377 			KEG_LOCK(keg);
2378 			if ((keg->uk_flags & UMA_ZFLAG_FULL) == 0) {
2379 				slab = keg_fetch_slab(keg, zone, flags);
2380 				if (slab)
2381 					return (slab);
2382 			}
2383 			if (keg->uk_flags & UMA_ZFLAG_FULL)
2384 				full++;
2385 			else
2386 				empty++;
2387 			KEG_UNLOCK(keg);
2388 		}
2389 		if (rflags & (M_NOWAIT | M_NOVM))
2390 			break;
2391 		flags = rflags;
2392 		/*
2393 		 * All kegs are full.  XXX We can't atomically check all kegs
2394 		 * and sleep so just sleep for a short period and retry.
2395 		 */
2396 		if (full && !empty) {
2397 			ZONE_LOCK(zone);
2398 			zone->uz_flags |= UMA_ZFLAG_FULL;
2399 			zone->uz_sleeps++;
2400 			zone_log_warning(zone);
2401 			zone_maxaction(zone);
2402 			msleep(zone, zone->uz_lockptr, PVM,
2403 			    "zonelimit", hz/100);
2404 			zone->uz_flags &= ~UMA_ZFLAG_FULL;
2405 			ZONE_UNLOCK(zone);
2406 			continue;
2407 		}
2408 	}
2409 	return (NULL);
2410 }
2411 
2412 static void *
2413 slab_alloc_item(uma_keg_t keg, uma_slab_t slab)
2414 {
2415 	void *item;
2416 	uint8_t freei;
2417 
2418 	MPASS(keg == slab->us_keg);
2419 	mtx_assert(&keg->uk_lock, MA_OWNED);
2420 
2421 	freei = BIT_FFS(SLAB_SETSIZE, &slab->us_free) - 1;
2422 	BIT_CLR(SLAB_SETSIZE, freei, &slab->us_free);
2423 	item = slab->us_data + (keg->uk_rsize * freei);
2424 	slab->us_freecount--;
2425 	keg->uk_free--;
2426 
2427 	/* Move this slab to the full list */
2428 	if (slab->us_freecount == 0) {
2429 		LIST_REMOVE(slab, us_link);
2430 		LIST_INSERT_HEAD(&keg->uk_full_slab, slab, us_link);
2431 	}
2432 
2433 	return (item);
2434 }
2435 
2436 static int
2437 zone_import(uma_zone_t zone, void **bucket, int max, int flags)
2438 {
2439 	uma_slab_t slab;
2440 	uma_keg_t keg;
2441 	int i;
2442 
2443 	slab = NULL;
2444 	keg = NULL;
2445 	/* Try to keep the buckets totally full */
2446 	for (i = 0; i < max; ) {
2447 		if ((slab = zone->uz_slab(zone, keg, flags)) == NULL)
2448 			break;
2449 		keg = slab->us_keg;
2450 		while (slab->us_freecount && i < max) {
2451 			bucket[i++] = slab_alloc_item(keg, slab);
2452 			if (keg->uk_free <= keg->uk_reserve)
2453 				break;
2454 		}
2455 		/* Don't grab more than one slab at a time. */
2456 		flags &= ~M_WAITOK;
2457 		flags |= M_NOWAIT;
2458 	}
2459 	if (slab != NULL)
2460 		KEG_UNLOCK(keg);
2461 
2462 	return i;
2463 }
2464 
2465 static uma_bucket_t
2466 zone_alloc_bucket(uma_zone_t zone, void *udata, int flags)
2467 {
2468 	uma_bucket_t bucket;
2469 	int max;
2470 
2471 	/* Don't wait for buckets, preserve caller's NOVM setting. */
2472 	bucket = bucket_alloc(zone, udata, M_NOWAIT | (flags & M_NOVM));
2473 	if (bucket == NULL)
2474 		return (NULL);
2475 
2476 	max = MIN(bucket->ub_entries, zone->uz_count);
2477 	bucket->ub_cnt = zone->uz_import(zone->uz_arg, bucket->ub_bucket,
2478 	    max, flags);
2479 
2480 	/*
2481 	 * Initialize the memory if necessary.
2482 	 */
2483 	if (bucket->ub_cnt != 0 && zone->uz_init != NULL) {
2484 		int i;
2485 
2486 		for (i = 0; i < bucket->ub_cnt; i++)
2487 			if (zone->uz_init(bucket->ub_bucket[i], zone->uz_size,
2488 			    flags) != 0)
2489 				break;
2490 		/*
2491 		 * If we couldn't initialize the whole bucket, put the
2492 		 * rest back onto the freelist.
2493 		 */
2494 		if (i != bucket->ub_cnt) {
2495 			zone->uz_release(zone->uz_arg, &bucket->ub_bucket[i],
2496 			    bucket->ub_cnt - i);
2497 #ifdef INVARIANTS
2498 			bzero(&bucket->ub_bucket[i],
2499 			    sizeof(void *) * (bucket->ub_cnt - i));
2500 #endif
2501 			bucket->ub_cnt = i;
2502 		}
2503 	}
2504 
2505 	if (bucket->ub_cnt == 0) {
2506 		bucket_free(zone, bucket, udata);
2507 		atomic_add_long(&zone->uz_fails, 1);
2508 		return (NULL);
2509 	}
2510 
2511 	return (bucket);
2512 }
2513 
2514 /*
2515  * Allocates a single item from a zone.
2516  *
2517  * Arguments
2518  *	zone   The zone to alloc for.
2519  *	udata  The data to be passed to the constructor.
2520  *	flags  M_WAITOK, M_NOWAIT, M_ZERO.
2521  *
2522  * Returns
2523  *	NULL if there is no memory and M_NOWAIT is set
2524  *	An item if successful
2525  */
2526 
2527 static void *
2528 zone_alloc_item(uma_zone_t zone, void *udata, int flags)
2529 {
2530 	void *item;
2531 
2532 	item = NULL;
2533 
2534 	if (zone->uz_import(zone->uz_arg, &item, 1, flags) != 1)
2535 		goto fail;
2536 	atomic_add_long(&zone->uz_allocs, 1);
2537 
2538 	/*
2539 	 * We have to call both the zone's init (not the keg's init)
2540 	 * and the zone's ctor.  This is because the item is going from
2541 	 * a keg slab directly to the user, and the user is expecting it
2542 	 * to be both zone-init'd as well as zone-ctor'd.
2543 	 */
2544 	if (zone->uz_init != NULL) {
2545 		if (zone->uz_init(item, zone->uz_size, flags) != 0) {
2546 			zone_free_item(zone, item, udata, SKIP_FINI);
2547 			goto fail;
2548 		}
2549 	}
2550 	if (zone->uz_ctor != NULL) {
2551 		if (zone->uz_ctor(item, zone->uz_size, udata, flags) != 0) {
2552 			zone_free_item(zone, item, udata, SKIP_DTOR);
2553 			goto fail;
2554 		}
2555 	}
2556 #ifdef INVARIANTS
2557 	uma_dbg_alloc(zone, NULL, item);
2558 #endif
2559 	if (flags & M_ZERO)
2560 		uma_zero_item(item, zone);
2561 
2562 	CTR3(KTR_UMA, "zone_alloc_item item %p from %s(%p)", item,
2563 	    zone->uz_name, zone);
2564 
2565 	return (item);
2566 
2567 fail:
2568 	CTR2(KTR_UMA, "zone_alloc_item failed from %s(%p)",
2569 	    zone->uz_name, zone);
2570 	atomic_add_long(&zone->uz_fails, 1);
2571 	return (NULL);
2572 }
2573 
2574 /* See uma.h */
2575 void
2576 uma_zfree_arg(uma_zone_t zone, void *item, void *udata)
2577 {
2578 	uma_cache_t cache;
2579 	uma_bucket_t bucket;
2580 	int lockfail;
2581 	int cpu;
2582 
2583 	/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
2584 	random_harvest_fast_uma(&zone, sizeof(zone), 1, RANDOM_UMA);
2585 
2586 	CTR2(KTR_UMA, "uma_zfree_arg thread %x zone %s", curthread,
2587 	    zone->uz_name);
2588 
2589 	KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
2590 	    ("uma_zfree_arg: called with spinlock or critical section held"));
2591 
2592         /* uma_zfree(..., NULL) does nothing, to match free(9). */
2593         if (item == NULL)
2594                 return;
2595 #ifdef DEBUG_MEMGUARD
2596 	if (is_memguard_addr(item)) {
2597 		if (zone->uz_dtor != NULL)
2598 			zone->uz_dtor(item, zone->uz_size, udata);
2599 		if (zone->uz_fini != NULL)
2600 			zone->uz_fini(item, zone->uz_size);
2601 		memguard_free(item);
2602 		return;
2603 	}
2604 #endif
2605 #ifdef INVARIANTS
2606 	if (zone->uz_flags & UMA_ZONE_MALLOC)
2607 		uma_dbg_free(zone, udata, item);
2608 	else
2609 		uma_dbg_free(zone, NULL, item);
2610 #endif
2611 	if (zone->uz_dtor != NULL)
2612 		zone->uz_dtor(item, zone->uz_size, udata);
2613 
2614 	/*
2615 	 * The race here is acceptable.  If we miss it we'll just have to wait
2616 	 * a little longer for the limits to be reset.
2617 	 */
2618 	if (zone->uz_flags & UMA_ZFLAG_FULL)
2619 		goto zfree_item;
2620 
2621 	/*
2622 	 * If possible, free to the per-CPU cache.  There are two
2623 	 * requirements for safe access to the per-CPU cache: (1) the thread
2624 	 * accessing the cache must not be preempted or yield during access,
2625 	 * and (2) the thread must not migrate CPUs without switching which
2626 	 * cache it accesses.  We rely on a critical section to prevent
2627 	 * preemption and migration.  We release the critical section in
2628 	 * order to acquire the zone mutex if we are unable to free to the
2629 	 * current cache; when we re-acquire the critical section, we must
2630 	 * detect and handle migration if it has occurred.
2631 	 */
2632 zfree_restart:
2633 	critical_enter();
2634 	cpu = curcpu;
2635 	cache = &zone->uz_cpu[cpu];
2636 
2637 zfree_start:
2638 	/*
2639 	 * Try to free into the allocbucket first to give LIFO ordering
2640 	 * for cache-hot datastructures.  Spill over into the freebucket
2641 	 * if necessary.  Alloc will swap them if one runs dry.
2642 	 */
2643 	bucket = cache->uc_allocbucket;
2644 	if (bucket == NULL || bucket->ub_cnt >= bucket->ub_entries)
2645 		bucket = cache->uc_freebucket;
2646 	if (bucket != NULL && bucket->ub_cnt < bucket->ub_entries) {
2647 		KASSERT(bucket->ub_bucket[bucket->ub_cnt] == NULL,
2648 		    ("uma_zfree: Freeing to non free bucket index."));
2649 		bucket->ub_bucket[bucket->ub_cnt] = item;
2650 		bucket->ub_cnt++;
2651 		cache->uc_frees++;
2652 		critical_exit();
2653 		return;
2654 	}
2655 
2656 	/*
2657 	 * We must go back the zone, which requires acquiring the zone lock,
2658 	 * which in turn means we must release and re-acquire the critical
2659 	 * section.  Since the critical section is released, we may be
2660 	 * preempted or migrate.  As such, make sure not to maintain any
2661 	 * thread-local state specific to the cache from prior to releasing
2662 	 * the critical section.
2663 	 */
2664 	critical_exit();
2665 	if (zone->uz_count == 0 || bucketdisable)
2666 		goto zfree_item;
2667 
2668 	lockfail = 0;
2669 	if (ZONE_TRYLOCK(zone) == 0) {
2670 		/* Record contention to size the buckets. */
2671 		ZONE_LOCK(zone);
2672 		lockfail = 1;
2673 	}
2674 	critical_enter();
2675 	cpu = curcpu;
2676 	cache = &zone->uz_cpu[cpu];
2677 
2678 	/*
2679 	 * Since we have locked the zone we may as well send back our stats.
2680 	 */
2681 	atomic_add_long(&zone->uz_allocs, cache->uc_allocs);
2682 	atomic_add_long(&zone->uz_frees, cache->uc_frees);
2683 	cache->uc_allocs = 0;
2684 	cache->uc_frees = 0;
2685 
2686 	bucket = cache->uc_freebucket;
2687 	if (bucket != NULL && bucket->ub_cnt < bucket->ub_entries) {
2688 		ZONE_UNLOCK(zone);
2689 		goto zfree_start;
2690 	}
2691 	cache->uc_freebucket = NULL;
2692 	/* We are no longer associated with this CPU. */
2693 	critical_exit();
2694 
2695 	/* Can we throw this on the zone full list? */
2696 	if (bucket != NULL) {
2697 		CTR3(KTR_UMA,
2698 		    "uma_zfree: zone %s(%p) putting bucket %p on free list",
2699 		    zone->uz_name, zone, bucket);
2700 		/* ub_cnt is pointing to the last free item */
2701 		KASSERT(bucket->ub_cnt != 0,
2702 		    ("uma_zfree: Attempting to insert an empty bucket onto the full list.\n"));
2703 		LIST_INSERT_HEAD(&zone->uz_buckets, bucket, ub_link);
2704 	}
2705 
2706 	/*
2707 	 * We bump the uz count when the cache size is insufficient to
2708 	 * handle the working set.
2709 	 */
2710 	if (lockfail && zone->uz_count < BUCKET_MAX)
2711 		zone->uz_count++;
2712 	ZONE_UNLOCK(zone);
2713 
2714 	bucket = bucket_alloc(zone, udata, M_NOWAIT);
2715 	CTR3(KTR_UMA, "uma_zfree: zone %s(%p) allocated bucket %p",
2716 	    zone->uz_name, zone, bucket);
2717 	if (bucket) {
2718 		critical_enter();
2719 		cpu = curcpu;
2720 		cache = &zone->uz_cpu[cpu];
2721 		if (cache->uc_freebucket == NULL) {
2722 			cache->uc_freebucket = bucket;
2723 			goto zfree_start;
2724 		}
2725 		/*
2726 		 * We lost the race, start over.  We have to drop our
2727 		 * critical section to free the bucket.
2728 		 */
2729 		critical_exit();
2730 		bucket_free(zone, bucket, udata);
2731 		goto zfree_restart;
2732 	}
2733 
2734 	/*
2735 	 * If nothing else caught this, we'll just do an internal free.
2736 	 */
2737 zfree_item:
2738 	zone_free_item(zone, item, udata, SKIP_DTOR);
2739 
2740 	return;
2741 }
2742 
2743 static void
2744 slab_free_item(uma_keg_t keg, uma_slab_t slab, void *item)
2745 {
2746 	uint8_t freei;
2747 
2748 	mtx_assert(&keg->uk_lock, MA_OWNED);
2749 	MPASS(keg == slab->us_keg);
2750 
2751 	/* Do we need to remove from any lists? */
2752 	if (slab->us_freecount+1 == keg->uk_ipers) {
2753 		LIST_REMOVE(slab, us_link);
2754 		LIST_INSERT_HEAD(&keg->uk_free_slab, slab, us_link);
2755 	} else if (slab->us_freecount == 0) {
2756 		LIST_REMOVE(slab, us_link);
2757 		LIST_INSERT_HEAD(&keg->uk_part_slab, slab, us_link);
2758 	}
2759 
2760 	/* Slab management. */
2761 	freei = ((uintptr_t)item - (uintptr_t)slab->us_data) / keg->uk_rsize;
2762 	BIT_SET(SLAB_SETSIZE, freei, &slab->us_free);
2763 	slab->us_freecount++;
2764 
2765 	/* Keg statistics. */
2766 	keg->uk_free++;
2767 }
2768 
2769 static void
2770 zone_release(uma_zone_t zone, void **bucket, int cnt)
2771 {
2772 	void *item;
2773 	uma_slab_t slab;
2774 	uma_keg_t keg;
2775 	uint8_t *mem;
2776 	int clearfull;
2777 	int i;
2778 
2779 	clearfull = 0;
2780 	keg = zone_first_keg(zone);
2781 	KEG_LOCK(keg);
2782 	for (i = 0; i < cnt; i++) {
2783 		item = bucket[i];
2784 		if (!(zone->uz_flags & UMA_ZONE_VTOSLAB)) {
2785 			mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
2786 			if (zone->uz_flags & UMA_ZONE_HASH) {
2787 				slab = hash_sfind(&keg->uk_hash, mem);
2788 			} else {
2789 				mem += keg->uk_pgoff;
2790 				slab = (uma_slab_t)mem;
2791 			}
2792 		} else {
2793 			slab = vtoslab((vm_offset_t)item);
2794 			if (slab->us_keg != keg) {
2795 				KEG_UNLOCK(keg);
2796 				keg = slab->us_keg;
2797 				KEG_LOCK(keg);
2798 			}
2799 		}
2800 		slab_free_item(keg, slab, item);
2801 		if (keg->uk_flags & UMA_ZFLAG_FULL) {
2802 			if (keg->uk_pages < keg->uk_maxpages) {
2803 				keg->uk_flags &= ~UMA_ZFLAG_FULL;
2804 				clearfull = 1;
2805 			}
2806 
2807 			/*
2808 			 * We can handle one more allocation. Since we're
2809 			 * clearing ZFLAG_FULL, wake up all procs blocked
2810 			 * on pages. This should be uncommon, so keeping this
2811 			 * simple for now (rather than adding count of blocked
2812 			 * threads etc).
2813 			 */
2814 			wakeup(keg);
2815 		}
2816 	}
2817 	KEG_UNLOCK(keg);
2818 	if (clearfull) {
2819 		ZONE_LOCK(zone);
2820 		zone->uz_flags &= ~UMA_ZFLAG_FULL;
2821 		wakeup(zone);
2822 		ZONE_UNLOCK(zone);
2823 	}
2824 
2825 }
2826 
2827 /*
2828  * Frees a single item to any zone.
2829  *
2830  * Arguments:
2831  *	zone   The zone to free to
2832  *	item   The item we're freeing
2833  *	udata  User supplied data for the dtor
2834  *	skip   Skip dtors and finis
2835  */
2836 static void
2837 zone_free_item(uma_zone_t zone, void *item, void *udata, enum zfreeskip skip)
2838 {
2839 
2840 #ifdef INVARIANTS
2841 	if (skip == SKIP_NONE) {
2842 		if (zone->uz_flags & UMA_ZONE_MALLOC)
2843 			uma_dbg_free(zone, udata, item);
2844 		else
2845 			uma_dbg_free(zone, NULL, item);
2846 	}
2847 #endif
2848 	if (skip < SKIP_DTOR && zone->uz_dtor)
2849 		zone->uz_dtor(item, zone->uz_size, udata);
2850 
2851 	if (skip < SKIP_FINI && zone->uz_fini)
2852 		zone->uz_fini(item, zone->uz_size);
2853 
2854 	atomic_add_long(&zone->uz_frees, 1);
2855 	zone->uz_release(zone->uz_arg, &item, 1);
2856 }
2857 
2858 /* See uma.h */
2859 int
2860 uma_zone_set_max(uma_zone_t zone, int nitems)
2861 {
2862 	uma_keg_t keg;
2863 
2864 	keg = zone_first_keg(zone);
2865 	if (keg == NULL)
2866 		return (0);
2867 	KEG_LOCK(keg);
2868 	keg->uk_maxpages = (nitems / keg->uk_ipers) * keg->uk_ppera;
2869 	if (keg->uk_maxpages * keg->uk_ipers < nitems)
2870 		keg->uk_maxpages += keg->uk_ppera;
2871 	nitems = (keg->uk_maxpages / keg->uk_ppera) * keg->uk_ipers;
2872 	KEG_UNLOCK(keg);
2873 
2874 	return (nitems);
2875 }
2876 
2877 /* See uma.h */
2878 int
2879 uma_zone_get_max(uma_zone_t zone)
2880 {
2881 	int nitems;
2882 	uma_keg_t keg;
2883 
2884 	keg = zone_first_keg(zone);
2885 	if (keg == NULL)
2886 		return (0);
2887 	KEG_LOCK(keg);
2888 	nitems = (keg->uk_maxpages / keg->uk_ppera) * keg->uk_ipers;
2889 	KEG_UNLOCK(keg);
2890 
2891 	return (nitems);
2892 }
2893 
2894 /* See uma.h */
2895 void
2896 uma_zone_set_warning(uma_zone_t zone, const char *warning)
2897 {
2898 
2899 	ZONE_LOCK(zone);
2900 	zone->uz_warning = warning;
2901 	ZONE_UNLOCK(zone);
2902 }
2903 
2904 /* See uma.h */
2905 void
2906 uma_zone_set_maxaction(uma_zone_t zone, uma_maxaction_t maxaction)
2907 {
2908 
2909 	ZONE_LOCK(zone);
2910 	TASK_INIT(&zone->uz_maxaction, 0, (task_fn_t *)maxaction, zone);
2911 	ZONE_UNLOCK(zone);
2912 }
2913 
2914 /* See uma.h */
2915 int
2916 uma_zone_get_cur(uma_zone_t zone)
2917 {
2918 	int64_t nitems;
2919 	u_int i;
2920 
2921 	ZONE_LOCK(zone);
2922 	nitems = zone->uz_allocs - zone->uz_frees;
2923 	CPU_FOREACH(i) {
2924 		/*
2925 		 * See the comment in sysctl_vm_zone_stats() regarding the
2926 		 * safety of accessing the per-cpu caches. With the zone lock
2927 		 * held, it is safe, but can potentially result in stale data.
2928 		 */
2929 		nitems += zone->uz_cpu[i].uc_allocs -
2930 		    zone->uz_cpu[i].uc_frees;
2931 	}
2932 	ZONE_UNLOCK(zone);
2933 
2934 	return (nitems < 0 ? 0 : nitems);
2935 }
2936 
2937 /* See uma.h */
2938 void
2939 uma_zone_set_init(uma_zone_t zone, uma_init uminit)
2940 {
2941 	uma_keg_t keg;
2942 
2943 	keg = zone_first_keg(zone);
2944 	KASSERT(keg != NULL, ("uma_zone_set_init: Invalid zone type"));
2945 	KEG_LOCK(keg);
2946 	KASSERT(keg->uk_pages == 0,
2947 	    ("uma_zone_set_init on non-empty keg"));
2948 	keg->uk_init = uminit;
2949 	KEG_UNLOCK(keg);
2950 }
2951 
2952 /* See uma.h */
2953 void
2954 uma_zone_set_fini(uma_zone_t zone, uma_fini fini)
2955 {
2956 	uma_keg_t keg;
2957 
2958 	keg = zone_first_keg(zone);
2959 	KASSERT(keg != NULL, ("uma_zone_set_fini: Invalid zone type"));
2960 	KEG_LOCK(keg);
2961 	KASSERT(keg->uk_pages == 0,
2962 	    ("uma_zone_set_fini on non-empty keg"));
2963 	keg->uk_fini = fini;
2964 	KEG_UNLOCK(keg);
2965 }
2966 
2967 /* See uma.h */
2968 void
2969 uma_zone_set_zinit(uma_zone_t zone, uma_init zinit)
2970 {
2971 
2972 	ZONE_LOCK(zone);
2973 	KASSERT(zone_first_keg(zone)->uk_pages == 0,
2974 	    ("uma_zone_set_zinit on non-empty keg"));
2975 	zone->uz_init = zinit;
2976 	ZONE_UNLOCK(zone);
2977 }
2978 
2979 /* See uma.h */
2980 void
2981 uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini)
2982 {
2983 
2984 	ZONE_LOCK(zone);
2985 	KASSERT(zone_first_keg(zone)->uk_pages == 0,
2986 	    ("uma_zone_set_zfini on non-empty keg"));
2987 	zone->uz_fini = zfini;
2988 	ZONE_UNLOCK(zone);
2989 }
2990 
2991 /* See uma.h */
2992 /* XXX uk_freef is not actually used with the zone locked */
2993 void
2994 uma_zone_set_freef(uma_zone_t zone, uma_free freef)
2995 {
2996 	uma_keg_t keg;
2997 
2998 	keg = zone_first_keg(zone);
2999 	KASSERT(keg != NULL, ("uma_zone_set_freef: Invalid zone type"));
3000 	KEG_LOCK(keg);
3001 	keg->uk_freef = freef;
3002 	KEG_UNLOCK(keg);
3003 }
3004 
3005 /* See uma.h */
3006 /* XXX uk_allocf is not actually used with the zone locked */
3007 void
3008 uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf)
3009 {
3010 	uma_keg_t keg;
3011 
3012 	keg = zone_first_keg(zone);
3013 	KEG_LOCK(keg);
3014 	keg->uk_allocf = allocf;
3015 	KEG_UNLOCK(keg);
3016 }
3017 
3018 /* See uma.h */
3019 void
3020 uma_zone_reserve(uma_zone_t zone, int items)
3021 {
3022 	uma_keg_t keg;
3023 
3024 	keg = zone_first_keg(zone);
3025 	if (keg == NULL)
3026 		return;
3027 	KEG_LOCK(keg);
3028 	keg->uk_reserve = items;
3029 	KEG_UNLOCK(keg);
3030 
3031 	return;
3032 }
3033 
3034 /* See uma.h */
3035 int
3036 uma_zone_reserve_kva(uma_zone_t zone, int count)
3037 {
3038 	uma_keg_t keg;
3039 	vm_offset_t kva;
3040 	u_int pages;
3041 
3042 	keg = zone_first_keg(zone);
3043 	if (keg == NULL)
3044 		return (0);
3045 	pages = count / keg->uk_ipers;
3046 
3047 	if (pages * keg->uk_ipers < count)
3048 		pages++;
3049 	pages *= keg->uk_ppera;
3050 
3051 #ifdef UMA_MD_SMALL_ALLOC
3052 	if (keg->uk_ppera > 1) {
3053 #else
3054 	if (1) {
3055 #endif
3056 		kva = kva_alloc((vm_size_t)pages * PAGE_SIZE);
3057 		if (kva == 0)
3058 			return (0);
3059 	} else
3060 		kva = 0;
3061 	KEG_LOCK(keg);
3062 	keg->uk_kva = kva;
3063 	keg->uk_offset = 0;
3064 	keg->uk_maxpages = pages;
3065 #ifdef UMA_MD_SMALL_ALLOC
3066 	keg->uk_allocf = (keg->uk_ppera > 1) ? noobj_alloc : uma_small_alloc;
3067 #else
3068 	keg->uk_allocf = noobj_alloc;
3069 #endif
3070 	keg->uk_flags |= UMA_ZONE_NOFREE;
3071 	KEG_UNLOCK(keg);
3072 
3073 	return (1);
3074 }
3075 
3076 /* See uma.h */
3077 void
3078 uma_prealloc(uma_zone_t zone, int items)
3079 {
3080 	int slabs;
3081 	uma_slab_t slab;
3082 	uma_keg_t keg;
3083 
3084 	keg = zone_first_keg(zone);
3085 	if (keg == NULL)
3086 		return;
3087 	KEG_LOCK(keg);
3088 	slabs = items / keg->uk_ipers;
3089 	if (slabs * keg->uk_ipers < items)
3090 		slabs++;
3091 	while (slabs > 0) {
3092 		slab = keg_alloc_slab(keg, zone, M_WAITOK);
3093 		if (slab == NULL)
3094 			break;
3095 		MPASS(slab->us_keg == keg);
3096 		LIST_INSERT_HEAD(&keg->uk_free_slab, slab, us_link);
3097 		slabs--;
3098 	}
3099 	KEG_UNLOCK(keg);
3100 }
3101 
3102 /* See uma.h */
3103 static void
3104 uma_reclaim_locked(bool kmem_danger)
3105 {
3106 
3107 	CTR0(KTR_UMA, "UMA: vm asked us to release pages!");
3108 	sx_assert(&uma_drain_lock, SA_XLOCKED);
3109 	bucket_enable();
3110 	zone_foreach(zone_drain);
3111 	if (vm_page_count_min() || kmem_danger) {
3112 		cache_drain_safe(NULL);
3113 		zone_foreach(zone_drain);
3114 	}
3115 	/*
3116 	 * Some slabs may have been freed but this zone will be visited early
3117 	 * we visit again so that we can free pages that are empty once other
3118 	 * zones are drained.  We have to do the same for buckets.
3119 	 */
3120 	zone_drain(slabzone);
3121 	bucket_zone_drain();
3122 }
3123 
3124 void
3125 uma_reclaim(void)
3126 {
3127 
3128 	sx_xlock(&uma_drain_lock);
3129 	uma_reclaim_locked(false);
3130 	sx_xunlock(&uma_drain_lock);
3131 }
3132 
3133 static int uma_reclaim_needed;
3134 
3135 void
3136 uma_reclaim_wakeup(void)
3137 {
3138 
3139 	uma_reclaim_needed = 1;
3140 	wakeup(&uma_reclaim_needed);
3141 }
3142 
3143 void
3144 uma_reclaim_worker(void *arg __unused)
3145 {
3146 
3147 	sx_xlock(&uma_drain_lock);
3148 	for (;;) {
3149 		sx_sleep(&uma_reclaim_needed, &uma_drain_lock, PVM,
3150 		    "umarcl", 0);
3151 		if (uma_reclaim_needed) {
3152 			uma_reclaim_needed = 0;
3153 			sx_xunlock(&uma_drain_lock);
3154 			EVENTHANDLER_INVOKE(vm_lowmem, VM_LOW_KMEM);
3155 			sx_xlock(&uma_drain_lock);
3156 			uma_reclaim_locked(true);
3157 		}
3158 	}
3159 }
3160 
3161 /* See uma.h */
3162 int
3163 uma_zone_exhausted(uma_zone_t zone)
3164 {
3165 	int full;
3166 
3167 	ZONE_LOCK(zone);
3168 	full = (zone->uz_flags & UMA_ZFLAG_FULL);
3169 	ZONE_UNLOCK(zone);
3170 	return (full);
3171 }
3172 
3173 int
3174 uma_zone_exhausted_nolock(uma_zone_t zone)
3175 {
3176 	return (zone->uz_flags & UMA_ZFLAG_FULL);
3177 }
3178 
3179 void *
3180 uma_large_malloc(vm_size_t size, int wait)
3181 {
3182 	void *mem;
3183 	uma_slab_t slab;
3184 	uint8_t flags;
3185 
3186 	slab = zone_alloc_item(slabzone, NULL, wait);
3187 	if (slab == NULL)
3188 		return (NULL);
3189 	mem = page_alloc(NULL, size, &flags, wait);
3190 	if (mem) {
3191 		vsetslab((vm_offset_t)mem, slab);
3192 		slab->us_data = mem;
3193 		slab->us_flags = flags | UMA_SLAB_MALLOC;
3194 		slab->us_size = size;
3195 	} else {
3196 		zone_free_item(slabzone, slab, NULL, SKIP_NONE);
3197 	}
3198 
3199 	return (mem);
3200 }
3201 
3202 void
3203 uma_large_free(uma_slab_t slab)
3204 {
3205 
3206 	page_free(slab->us_data, slab->us_size, slab->us_flags);
3207 	zone_free_item(slabzone, slab, NULL, SKIP_NONE);
3208 }
3209 
3210 static void
3211 uma_zero_item(void *item, uma_zone_t zone)
3212 {
3213 	int i;
3214 
3215 	if (zone->uz_flags & UMA_ZONE_PCPU) {
3216 		CPU_FOREACH(i)
3217 			bzero(zpcpu_get_cpu(item, i), zone->uz_size);
3218 	} else
3219 		bzero(item, zone->uz_size);
3220 }
3221 
3222 void
3223 uma_print_stats(void)
3224 {
3225 	zone_foreach(uma_print_zone);
3226 }
3227 
3228 static void
3229 slab_print(uma_slab_t slab)
3230 {
3231 	printf("slab: keg %p, data %p, freecount %d\n",
3232 		slab->us_keg, slab->us_data, slab->us_freecount);
3233 }
3234 
3235 static void
3236 cache_print(uma_cache_t cache)
3237 {
3238 	printf("alloc: %p(%d), free: %p(%d)\n",
3239 		cache->uc_allocbucket,
3240 		cache->uc_allocbucket?cache->uc_allocbucket->ub_cnt:0,
3241 		cache->uc_freebucket,
3242 		cache->uc_freebucket?cache->uc_freebucket->ub_cnt:0);
3243 }
3244 
3245 static void
3246 uma_print_keg(uma_keg_t keg)
3247 {
3248 	uma_slab_t slab;
3249 
3250 	printf("keg: %s(%p) size %d(%d) flags %#x ipers %d ppera %d "
3251 	    "out %d free %d limit %d\n",
3252 	    keg->uk_name, keg, keg->uk_size, keg->uk_rsize, keg->uk_flags,
3253 	    keg->uk_ipers, keg->uk_ppera,
3254 	    (keg->uk_pages / keg->uk_ppera) * keg->uk_ipers - keg->uk_free,
3255 	    keg->uk_free, (keg->uk_maxpages / keg->uk_ppera) * keg->uk_ipers);
3256 	printf("Part slabs:\n");
3257 	LIST_FOREACH(slab, &keg->uk_part_slab, us_link)
3258 		slab_print(slab);
3259 	printf("Free slabs:\n");
3260 	LIST_FOREACH(slab, &keg->uk_free_slab, us_link)
3261 		slab_print(slab);
3262 	printf("Full slabs:\n");
3263 	LIST_FOREACH(slab, &keg->uk_full_slab, us_link)
3264 		slab_print(slab);
3265 }
3266 
3267 void
3268 uma_print_zone(uma_zone_t zone)
3269 {
3270 	uma_cache_t cache;
3271 	uma_klink_t kl;
3272 	int i;
3273 
3274 	printf("zone: %s(%p) size %d flags %#x\n",
3275 	    zone->uz_name, zone, zone->uz_size, zone->uz_flags);
3276 	LIST_FOREACH(kl, &zone->uz_kegs, kl_link)
3277 		uma_print_keg(kl->kl_keg);
3278 	CPU_FOREACH(i) {
3279 		cache = &zone->uz_cpu[i];
3280 		printf("CPU %d Cache:\n", i);
3281 		cache_print(cache);
3282 	}
3283 }
3284 
3285 #ifdef DDB
3286 /*
3287  * Generate statistics across both the zone and its per-cpu cache's.  Return
3288  * desired statistics if the pointer is non-NULL for that statistic.
3289  *
3290  * Note: does not update the zone statistics, as it can't safely clear the
3291  * per-CPU cache statistic.
3292  *
3293  * XXXRW: Following the uc_allocbucket and uc_freebucket pointers here isn't
3294  * safe from off-CPU; we should modify the caches to track this information
3295  * directly so that we don't have to.
3296  */
3297 static void
3298 uma_zone_sumstat(uma_zone_t z, int *cachefreep, uint64_t *allocsp,
3299     uint64_t *freesp, uint64_t *sleepsp)
3300 {
3301 	uma_cache_t cache;
3302 	uint64_t allocs, frees, sleeps;
3303 	int cachefree, cpu;
3304 
3305 	allocs = frees = sleeps = 0;
3306 	cachefree = 0;
3307 	CPU_FOREACH(cpu) {
3308 		cache = &z->uz_cpu[cpu];
3309 		if (cache->uc_allocbucket != NULL)
3310 			cachefree += cache->uc_allocbucket->ub_cnt;
3311 		if (cache->uc_freebucket != NULL)
3312 			cachefree += cache->uc_freebucket->ub_cnt;
3313 		allocs += cache->uc_allocs;
3314 		frees += cache->uc_frees;
3315 	}
3316 	allocs += z->uz_allocs;
3317 	frees += z->uz_frees;
3318 	sleeps += z->uz_sleeps;
3319 	if (cachefreep != NULL)
3320 		*cachefreep = cachefree;
3321 	if (allocsp != NULL)
3322 		*allocsp = allocs;
3323 	if (freesp != NULL)
3324 		*freesp = frees;
3325 	if (sleepsp != NULL)
3326 		*sleepsp = sleeps;
3327 }
3328 #endif /* DDB */
3329 
3330 static int
3331 sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS)
3332 {
3333 	uma_keg_t kz;
3334 	uma_zone_t z;
3335 	int count;
3336 
3337 	count = 0;
3338 	rw_rlock(&uma_rwlock);
3339 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3340 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
3341 			count++;
3342 	}
3343 	rw_runlock(&uma_rwlock);
3344 	return (sysctl_handle_int(oidp, &count, 0, req));
3345 }
3346 
3347 static int
3348 sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS)
3349 {
3350 	struct uma_stream_header ush;
3351 	struct uma_type_header uth;
3352 	struct uma_percpu_stat ups;
3353 	uma_bucket_t bucket;
3354 	struct sbuf sbuf;
3355 	uma_cache_t cache;
3356 	uma_klink_t kl;
3357 	uma_keg_t kz;
3358 	uma_zone_t z;
3359 	uma_keg_t k;
3360 	int count, error, i;
3361 
3362 	error = sysctl_wire_old_buffer(req, 0);
3363 	if (error != 0)
3364 		return (error);
3365 	sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
3366 	sbuf_clear_flags(&sbuf, SBUF_INCLUDENUL);
3367 
3368 	count = 0;
3369 	rw_rlock(&uma_rwlock);
3370 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3371 		LIST_FOREACH(z, &kz->uk_zones, uz_link)
3372 			count++;
3373 	}
3374 
3375 	/*
3376 	 * Insert stream header.
3377 	 */
3378 	bzero(&ush, sizeof(ush));
3379 	ush.ush_version = UMA_STREAM_VERSION;
3380 	ush.ush_maxcpus = (mp_maxid + 1);
3381 	ush.ush_count = count;
3382 	(void)sbuf_bcat(&sbuf, &ush, sizeof(ush));
3383 
3384 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3385 		LIST_FOREACH(z, &kz->uk_zones, uz_link) {
3386 			bzero(&uth, sizeof(uth));
3387 			ZONE_LOCK(z);
3388 			strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
3389 			uth.uth_align = kz->uk_align;
3390 			uth.uth_size = kz->uk_size;
3391 			uth.uth_rsize = kz->uk_rsize;
3392 			LIST_FOREACH(kl, &z->uz_kegs, kl_link) {
3393 				k = kl->kl_keg;
3394 				uth.uth_maxpages += k->uk_maxpages;
3395 				uth.uth_pages += k->uk_pages;
3396 				uth.uth_keg_free += k->uk_free;
3397 				uth.uth_limit = (k->uk_maxpages / k->uk_ppera)
3398 				    * k->uk_ipers;
3399 			}
3400 
3401 			/*
3402 			 * A zone is secondary is it is not the first entry
3403 			 * on the keg's zone list.
3404 			 */
3405 			if ((z->uz_flags & UMA_ZONE_SECONDARY) &&
3406 			    (LIST_FIRST(&kz->uk_zones) != z))
3407 				uth.uth_zone_flags = UTH_ZONE_SECONDARY;
3408 
3409 			LIST_FOREACH(bucket, &z->uz_buckets, ub_link)
3410 				uth.uth_zone_free += bucket->ub_cnt;
3411 			uth.uth_allocs = z->uz_allocs;
3412 			uth.uth_frees = z->uz_frees;
3413 			uth.uth_fails = z->uz_fails;
3414 			uth.uth_sleeps = z->uz_sleeps;
3415 			(void)sbuf_bcat(&sbuf, &uth, sizeof(uth));
3416 			/*
3417 			 * While it is not normally safe to access the cache
3418 			 * bucket pointers while not on the CPU that owns the
3419 			 * cache, we only allow the pointers to be exchanged
3420 			 * without the zone lock held, not invalidated, so
3421 			 * accept the possible race associated with bucket
3422 			 * exchange during monitoring.
3423 			 */
3424 			for (i = 0; i < (mp_maxid + 1); i++) {
3425 				bzero(&ups, sizeof(ups));
3426 				if (kz->uk_flags & UMA_ZFLAG_INTERNAL)
3427 					goto skip;
3428 				if (CPU_ABSENT(i))
3429 					goto skip;
3430 				cache = &z->uz_cpu[i];
3431 				if (cache->uc_allocbucket != NULL)
3432 					ups.ups_cache_free +=
3433 					    cache->uc_allocbucket->ub_cnt;
3434 				if (cache->uc_freebucket != NULL)
3435 					ups.ups_cache_free +=
3436 					    cache->uc_freebucket->ub_cnt;
3437 				ups.ups_allocs = cache->uc_allocs;
3438 				ups.ups_frees = cache->uc_frees;
3439 skip:
3440 				(void)sbuf_bcat(&sbuf, &ups, sizeof(ups));
3441 			}
3442 			ZONE_UNLOCK(z);
3443 		}
3444 	}
3445 	rw_runlock(&uma_rwlock);
3446 	error = sbuf_finish(&sbuf);
3447 	sbuf_delete(&sbuf);
3448 	return (error);
3449 }
3450 
3451 int
3452 sysctl_handle_uma_zone_max(SYSCTL_HANDLER_ARGS)
3453 {
3454 	uma_zone_t zone = *(uma_zone_t *)arg1;
3455 	int error, max;
3456 
3457 	max = uma_zone_get_max(zone);
3458 	error = sysctl_handle_int(oidp, &max, 0, req);
3459 	if (error || !req->newptr)
3460 		return (error);
3461 
3462 	uma_zone_set_max(zone, max);
3463 
3464 	return (0);
3465 }
3466 
3467 int
3468 sysctl_handle_uma_zone_cur(SYSCTL_HANDLER_ARGS)
3469 {
3470 	uma_zone_t zone = *(uma_zone_t *)arg1;
3471 	int cur;
3472 
3473 	cur = uma_zone_get_cur(zone);
3474 	return (sysctl_handle_int(oidp, &cur, 0, req));
3475 }
3476 
3477 #ifdef INVARIANTS
3478 static uma_slab_t
3479 uma_dbg_getslab(uma_zone_t zone, void *item)
3480 {
3481 	uma_slab_t slab;
3482 	uma_keg_t keg;
3483 	uint8_t *mem;
3484 
3485 	mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
3486 	if (zone->uz_flags & UMA_ZONE_VTOSLAB) {
3487 		slab = vtoslab((vm_offset_t)mem);
3488 	} else {
3489 		/*
3490 		 * It is safe to return the slab here even though the
3491 		 * zone is unlocked because the item's allocation state
3492 		 * essentially holds a reference.
3493 		 */
3494 		ZONE_LOCK(zone);
3495 		keg = LIST_FIRST(&zone->uz_kegs)->kl_keg;
3496 		if (keg->uk_flags & UMA_ZONE_HASH)
3497 			slab = hash_sfind(&keg->uk_hash, mem);
3498 		else
3499 			slab = (uma_slab_t)(mem + keg->uk_pgoff);
3500 		ZONE_UNLOCK(zone);
3501 	}
3502 
3503 	return (slab);
3504 }
3505 
3506 /*
3507  * Set up the slab's freei data such that uma_dbg_free can function.
3508  *
3509  */
3510 static void
3511 uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item)
3512 {
3513 	uma_keg_t keg;
3514 	int freei;
3515 
3516 	if (zone_first_keg(zone) == NULL)
3517 		return;
3518 	if (slab == NULL) {
3519 		slab = uma_dbg_getslab(zone, item);
3520 		if (slab == NULL)
3521 			panic("uma: item %p did not belong to zone %s\n",
3522 			    item, zone->uz_name);
3523 	}
3524 	keg = slab->us_keg;
3525 	freei = ((uintptr_t)item - (uintptr_t)slab->us_data) / keg->uk_rsize;
3526 
3527 	if (BIT_ISSET(SLAB_SETSIZE, freei, &slab->us_debugfree))
3528 		panic("Duplicate alloc of %p from zone %p(%s) slab %p(%d)\n",
3529 		    item, zone, zone->uz_name, slab, freei);
3530 	BIT_SET_ATOMIC(SLAB_SETSIZE, freei, &slab->us_debugfree);
3531 
3532 	return;
3533 }
3534 
3535 /*
3536  * Verifies freed addresses.  Checks for alignment, valid slab membership
3537  * and duplicate frees.
3538  *
3539  */
3540 static void
3541 uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item)
3542 {
3543 	uma_keg_t keg;
3544 	int freei;
3545 
3546 	if (zone_first_keg(zone) == NULL)
3547 		return;
3548 	if (slab == NULL) {
3549 		slab = uma_dbg_getslab(zone, item);
3550 		if (slab == NULL)
3551 			panic("uma: Freed item %p did not belong to zone %s\n",
3552 			    item, zone->uz_name);
3553 	}
3554 	keg = slab->us_keg;
3555 	freei = ((uintptr_t)item - (uintptr_t)slab->us_data) / keg->uk_rsize;
3556 
3557 	if (freei >= keg->uk_ipers)
3558 		panic("Invalid free of %p from zone %p(%s) slab %p(%d)\n",
3559 		    item, zone, zone->uz_name, slab, freei);
3560 
3561 	if (((freei * keg->uk_rsize) + slab->us_data) != item)
3562 		panic("Unaligned free of %p from zone %p(%s) slab %p(%d)\n",
3563 		    item, zone, zone->uz_name, slab, freei);
3564 
3565 	if (!BIT_ISSET(SLAB_SETSIZE, freei, &slab->us_debugfree))
3566 		panic("Duplicate free of %p from zone %p(%s) slab %p(%d)\n",
3567 		    item, zone, zone->uz_name, slab, freei);
3568 
3569 	BIT_CLR_ATOMIC(SLAB_SETSIZE, freei, &slab->us_debugfree);
3570 }
3571 #endif /* INVARIANTS */
3572 
3573 #ifdef DDB
3574 DB_SHOW_COMMAND(uma, db_show_uma)
3575 {
3576 	uint64_t allocs, frees, sleeps;
3577 	uma_bucket_t bucket;
3578 	uma_keg_t kz;
3579 	uma_zone_t z;
3580 	int cachefree;
3581 
3582 	db_printf("%18s %8s %8s %8s %12s %8s %8s\n", "Zone", "Size", "Used",
3583 	    "Free", "Requests", "Sleeps", "Bucket");
3584 	LIST_FOREACH(kz, &uma_kegs, uk_link) {
3585 		LIST_FOREACH(z, &kz->uk_zones, uz_link) {
3586 			if (kz->uk_flags & UMA_ZFLAG_INTERNAL) {
3587 				allocs = z->uz_allocs;
3588 				frees = z->uz_frees;
3589 				sleeps = z->uz_sleeps;
3590 				cachefree = 0;
3591 			} else
3592 				uma_zone_sumstat(z, &cachefree, &allocs,
3593 				    &frees, &sleeps);
3594 			if (!((z->uz_flags & UMA_ZONE_SECONDARY) &&
3595 			    (LIST_FIRST(&kz->uk_zones) != z)))
3596 				cachefree += kz->uk_free;
3597 			LIST_FOREACH(bucket, &z->uz_buckets, ub_link)
3598 				cachefree += bucket->ub_cnt;
3599 			db_printf("%18s %8ju %8jd %8d %12ju %8ju %8u\n",
3600 			    z->uz_name, (uintmax_t)kz->uk_size,
3601 			    (intmax_t)(allocs - frees), cachefree,
3602 			    (uintmax_t)allocs, sleeps, z->uz_count);
3603 			if (db_pager_quit)
3604 				return;
3605 		}
3606 	}
3607 }
3608 
3609 DB_SHOW_COMMAND(umacache, db_show_umacache)
3610 {
3611 	uint64_t allocs, frees;
3612 	uma_bucket_t bucket;
3613 	uma_zone_t z;
3614 	int cachefree;
3615 
3616 	db_printf("%18s %8s %8s %8s %12s %8s\n", "Zone", "Size", "Used", "Free",
3617 	    "Requests", "Bucket");
3618 	LIST_FOREACH(z, &uma_cachezones, uz_link) {
3619 		uma_zone_sumstat(z, &cachefree, &allocs, &frees, NULL);
3620 		LIST_FOREACH(bucket, &z->uz_buckets, ub_link)
3621 			cachefree += bucket->ub_cnt;
3622 		db_printf("%18s %8ju %8jd %8d %12ju %8u\n",
3623 		    z->uz_name, (uintmax_t)z->uz_size,
3624 		    (intmax_t)(allocs - frees), cachefree,
3625 		    (uintmax_t)allocs, z->uz_count);
3626 		if (db_pager_quit)
3627 			return;
3628 	}
3629 }
3630 #endif	/* DDB */
3631