FreeBSD/Linux Kernel Cross Reference
sys/vm/uma_core.c
1 /*-
2 * Copyright (c) 2002, 2003, 2004, 2005 Jeffrey Roberson <jeff@FreeBSD.org>
3 * Copyright (c) 2004, 2005 Bosko Milekic <bmilekic@FreeBSD.org>
4 * Copyright (c) 2004-2005 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 * effecient. 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: releng/6.1/sys/vm/uma_core.c 161685 2006-08-28 07:31:11Z cperciva $");
52
53 /* I should really use ktr.. */
54 /*
55 #define UMA_DEBUG 1
56 #define UMA_DEBUG_ALLOC 1
57 #define UMA_DEBUG_ALLOC_1 1
58 */
59
60 #include "opt_ddb.h"
61 #include "opt_param.h"
62
63 #include <sys/param.h>
64 #include <sys/systm.h>
65 #include <sys/kernel.h>
66 #include <sys/types.h>
67 #include <sys/queue.h>
68 #include <sys/malloc.h>
69 #include <sys/ktr.h>
70 #include <sys/lock.h>
71 #include <sys/sysctl.h>
72 #include <sys/mutex.h>
73 #include <sys/proc.h>
74 #include <sys/sbuf.h>
75 #include <sys/smp.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_param.h>
82 #include <vm/vm_map.h>
83 #include <vm/vm_kern.h>
84 #include <vm/vm_extern.h>
85 #include <vm/uma.h>
86 #include <vm/uma_int.h>
87 #include <vm/uma_dbg.h>
88
89 #include <machine/vmparam.h>
90
91 #include <ddb/ddb.h>
92
93 /*
94 * This is the zone and keg from which all zones are spawned. The idea is that
95 * even the zone & keg heads are allocated from the allocator, so we use the
96 * bss section to bootstrap us.
97 */
98 static struct uma_keg masterkeg;
99 static struct uma_zone masterzone_k;
100 static struct uma_zone masterzone_z;
101 static uma_zone_t kegs = &masterzone_k;
102 static uma_zone_t zones = &masterzone_z;
103
104 /* This is the zone from which all of uma_slab_t's are allocated. */
105 static uma_zone_t slabzone;
106 static uma_zone_t slabrefzone; /* With refcounters (for UMA_ZONE_REFCNT) */
107
108 /*
109 * The initial hash tables come out of this zone so they can be allocated
110 * prior to malloc coming up.
111 */
112 static uma_zone_t hashzone;
113
114 static MALLOC_DEFINE(M_UMAHASH, "UMAHash", "UMA Hash Buckets");
115
116 /*
117 * Are we allowed to allocate buckets?
118 */
119 static int bucketdisable = 1;
120
121 /* Linked list of all kegs in the system */
122 static LIST_HEAD(,uma_keg) uma_kegs = LIST_HEAD_INITIALIZER(&uma_kegs);
123
124 /* This mutex protects the keg list */
125 static struct mtx uma_mtx;
126
127 /* Linked list of boot time pages */
128 static LIST_HEAD(,uma_slab) uma_boot_pages =
129 LIST_HEAD_INITIALIZER(&uma_boot_pages);
130
131 /* This mutex protects the boot time pages list */
132 static struct mtx uma_boot_pages_mtx;
133
134 /* Is the VM done starting up? */
135 static int booted = 0;
136
137 /* Maximum number of allowed items-per-slab if the slab header is OFFPAGE */
138 static u_int uma_max_ipers;
139 static u_int uma_max_ipers_ref;
140
141 /*
142 * This is the handle used to schedule events that need to happen
143 * outside of the allocation fast path.
144 */
145 static struct callout uma_callout;
146 #define UMA_TIMEOUT 20 /* Seconds for callout interval. */
147
148 /*
149 * This structure is passed as the zone ctor arg so that I don't have to create
150 * a special allocation function just for zones.
151 */
152 struct uma_zctor_args {
153 char *name;
154 size_t size;
155 uma_ctor ctor;
156 uma_dtor dtor;
157 uma_init uminit;
158 uma_fini fini;
159 uma_keg_t keg;
160 int align;
161 u_int32_t flags;
162 };
163
164 struct uma_kctor_args {
165 uma_zone_t zone;
166 size_t size;
167 uma_init uminit;
168 uma_fini fini;
169 int align;
170 u_int32_t flags;
171 };
172
173 struct uma_bucket_zone {
174 uma_zone_t ubz_zone;
175 char *ubz_name;
176 int ubz_entries;
177 };
178
179 #define BUCKET_MAX 128
180
181 struct uma_bucket_zone bucket_zones[] = {
182 { NULL, "16 Bucket", 16 },
183 { NULL, "32 Bucket", 32 },
184 { NULL, "64 Bucket", 64 },
185 { NULL, "128 Bucket", 128 },
186 { NULL, NULL, 0}
187 };
188
189 #define BUCKET_SHIFT 4
190 #define BUCKET_ZONES ((BUCKET_MAX >> BUCKET_SHIFT) + 1)
191
192 /*
193 * bucket_size[] maps requested bucket sizes to zones that allocate a bucket
194 * of approximately the right size.
195 */
196 static uint8_t bucket_size[BUCKET_ZONES];
197
198 /*
199 * Flags and enumerations to be passed to internal functions.
200 */
201 enum zfreeskip { SKIP_NONE, SKIP_DTOR, SKIP_FINI };
202
203 #define ZFREE_STATFAIL 0x00000001 /* Update zone failure statistic. */
204 #define ZFREE_STATFREE 0x00000002 /* Update zone free statistic. */
205
206 /* Prototypes.. */
207
208 static void *obj_alloc(uma_zone_t, int, u_int8_t *, int);
209 static void *page_alloc(uma_zone_t, int, u_int8_t *, int);
210 static void *startup_alloc(uma_zone_t, int, u_int8_t *, int);
211 static void page_free(void *, int, u_int8_t);
212 static uma_slab_t slab_zalloc(uma_zone_t, int);
213 static void cache_drain(uma_zone_t);
214 static void bucket_drain(uma_zone_t, uma_bucket_t);
215 static void bucket_cache_drain(uma_zone_t zone);
216 static int keg_ctor(void *, int, void *, int);
217 static void keg_dtor(void *, int, void *);
218 static int zone_ctor(void *, int, void *, int);
219 static void zone_dtor(void *, int, void *);
220 static int zero_init(void *, int, int);
221 static void zone_small_init(uma_zone_t zone);
222 static void zone_large_init(uma_zone_t zone);
223 static void zone_foreach(void (*zfunc)(uma_zone_t));
224 static void zone_timeout(uma_zone_t zone);
225 static int hash_alloc(struct uma_hash *);
226 static int hash_expand(struct uma_hash *, struct uma_hash *);
227 static void hash_free(struct uma_hash *hash);
228 static void uma_timeout(void *);
229 static void uma_startup3(void);
230 static void *uma_zalloc_internal(uma_zone_t, void *, int);
231 static void uma_zfree_internal(uma_zone_t, void *, void *, enum zfreeskip,
232 int);
233 static void bucket_enable(void);
234 static void bucket_init(void);
235 static uma_bucket_t bucket_alloc(int, int);
236 static void bucket_free(uma_bucket_t);
237 static void bucket_zone_drain(void);
238 static int uma_zalloc_bucket(uma_zone_t zone, int flags);
239 static uma_slab_t uma_zone_slab(uma_zone_t zone, int flags);
240 static void *uma_slab_alloc(uma_zone_t zone, uma_slab_t slab);
241 static void zone_drain(uma_zone_t);
242 static uma_zone_t uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit,
243 uma_fini fini, int align, u_int32_t flags);
244
245 void uma_print_zone(uma_zone_t);
246 void uma_print_stats(void);
247 static int sysctl_vm_zone(SYSCTL_HANDLER_ARGS);
248 static int sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS);
249 static int sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS);
250
251 #ifdef WITNESS
252 static int nosleepwithlocks = 1;
253 SYSCTL_INT(_debug, OID_AUTO, nosleepwithlocks, CTLFLAG_RW, &nosleepwithlocks,
254 0, "Convert M_WAITOK to M_NOWAIT to avoid lock-held-across-sleep paths");
255 #else
256 static int nosleepwithlocks = 0;
257 SYSCTL_INT(_debug, OID_AUTO, nosleepwithlocks, CTLFLAG_RW, &nosleepwithlocks,
258 0, "Convert M_WAITOK to M_NOWAIT to avoid lock-held-across-sleep paths");
259 #endif
260 SYSCTL_OID(_vm, OID_AUTO, zone, CTLTYPE_STRING|CTLFLAG_RD,
261 NULL, 0, sysctl_vm_zone, "A", "Zone Info");
262 SYSINIT(uma_startup3, SI_SUB_VM_CONF, SI_ORDER_SECOND, uma_startup3, NULL);
263
264 SYSCTL_PROC(_vm, OID_AUTO, zone_count, CTLFLAG_RD|CTLTYPE_INT,
265 0, 0, sysctl_vm_zone_count, "I", "Number of UMA zones");
266
267 SYSCTL_PROC(_vm, OID_AUTO, zone_stats, CTLFLAG_RD|CTLTYPE_STRUCT,
268 0, 0, sysctl_vm_zone_stats, "s,struct uma_type_header", "Zone Stats");
269
270 /*
271 * This routine checks to see whether or not it's safe to enable buckets.
272 */
273
274 static void
275 bucket_enable(void)
276 {
277 if (cnt.v_free_count < cnt.v_free_min)
278 bucketdisable = 1;
279 else
280 bucketdisable = 0;
281 }
282
283 /*
284 * Initialize bucket_zones, the array of zones of buckets of various sizes.
285 *
286 * For each zone, calculate the memory required for each bucket, consisting
287 * of the header and an array of pointers. Initialize bucket_size[] to point
288 * the range of appropriate bucket sizes at the zone.
289 */
290 static void
291 bucket_init(void)
292 {
293 struct uma_bucket_zone *ubz;
294 int i;
295 int j;
296
297 for (i = 0, j = 0; bucket_zones[j].ubz_entries != 0; j++) {
298 int size;
299
300 ubz = &bucket_zones[j];
301 size = roundup(sizeof(struct uma_bucket), sizeof(void *));
302 size += sizeof(void *) * ubz->ubz_entries;
303 ubz->ubz_zone = uma_zcreate(ubz->ubz_name, size,
304 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
305 for (; i <= ubz->ubz_entries; i += (1 << BUCKET_SHIFT))
306 bucket_size[i >> BUCKET_SHIFT] = j;
307 }
308 }
309
310 /*
311 * Given a desired number of entries for a bucket, return the zone from which
312 * to allocate the bucket.
313 */
314 static struct uma_bucket_zone *
315 bucket_zone_lookup(int entries)
316 {
317 int idx;
318
319 idx = howmany(entries, 1 << BUCKET_SHIFT);
320 return (&bucket_zones[bucket_size[idx]]);
321 }
322
323 static uma_bucket_t
324 bucket_alloc(int entries, int bflags)
325 {
326 struct uma_bucket_zone *ubz;
327 uma_bucket_t bucket;
328
329 /*
330 * This is to stop us from allocating per cpu buckets while we're
331 * running out of vm.boot_pages. Otherwise, we would exhaust the
332 * boot pages. This also prevents us from allocating buckets in
333 * low memory situations.
334 */
335 if (bucketdisable)
336 return (NULL);
337
338 ubz = bucket_zone_lookup(entries);
339 bucket = uma_zalloc_internal(ubz->ubz_zone, NULL, bflags);
340 if (bucket) {
341 #ifdef INVARIANTS
342 bzero(bucket->ub_bucket, sizeof(void *) * ubz->ubz_entries);
343 #endif
344 bucket->ub_cnt = 0;
345 bucket->ub_entries = ubz->ubz_entries;
346 }
347
348 return (bucket);
349 }
350
351 static void
352 bucket_free(uma_bucket_t bucket)
353 {
354 struct uma_bucket_zone *ubz;
355
356 ubz = bucket_zone_lookup(bucket->ub_entries);
357 uma_zfree_internal(ubz->ubz_zone, bucket, NULL, SKIP_NONE,
358 ZFREE_STATFREE);
359 }
360
361 static void
362 bucket_zone_drain(void)
363 {
364 struct uma_bucket_zone *ubz;
365
366 for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
367 zone_drain(ubz->ubz_zone);
368 }
369
370
371 /*
372 * Routine called by timeout which is used to fire off some time interval
373 * based calculations. (stats, hash size, etc.)
374 *
375 * Arguments:
376 * arg Unused
377 *
378 * Returns:
379 * Nothing
380 */
381 static void
382 uma_timeout(void *unused)
383 {
384 bucket_enable();
385 zone_foreach(zone_timeout);
386
387 /* Reschedule this event */
388 callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
389 }
390
391 /*
392 * Routine to perform timeout driven calculations. This expands the
393 * hashes and does per cpu statistics aggregation.
394 *
395 * Arguments:
396 * zone The zone to operate on
397 *
398 * Returns:
399 * Nothing
400 */
401 static void
402 zone_timeout(uma_zone_t zone)
403 {
404 uma_keg_t keg;
405 u_int64_t alloc;
406
407 keg = zone->uz_keg;
408 alloc = 0;
409
410 /*
411 * Expand the zone hash table.
412 *
413 * This is done if the number of slabs is larger than the hash size.
414 * What I'm trying to do here is completely reduce collisions. This
415 * may be a little aggressive. Should I allow for two collisions max?
416 */
417 ZONE_LOCK(zone);
418 if (keg->uk_flags & UMA_ZONE_HASH &&
419 keg->uk_pages / keg->uk_ppera >= keg->uk_hash.uh_hashsize) {
420 struct uma_hash newhash;
421 struct uma_hash oldhash;
422 int ret;
423
424 /*
425 * This is so involved because allocating and freeing
426 * while the zone lock is held will lead to deadlock.
427 * I have to do everything in stages and check for
428 * races.
429 */
430 newhash = keg->uk_hash;
431 ZONE_UNLOCK(zone);
432 ret = hash_alloc(&newhash);
433 ZONE_LOCK(zone);
434 if (ret) {
435 if (hash_expand(&keg->uk_hash, &newhash)) {
436 oldhash = keg->uk_hash;
437 keg->uk_hash = newhash;
438 } else
439 oldhash = newhash;
440
441 ZONE_UNLOCK(zone);
442 hash_free(&oldhash);
443 ZONE_LOCK(zone);
444 }
445 }
446 ZONE_UNLOCK(zone);
447 }
448
449 /*
450 * Allocate and zero fill the next sized hash table from the appropriate
451 * backing store.
452 *
453 * Arguments:
454 * hash A new hash structure with the old hash size in uh_hashsize
455 *
456 * Returns:
457 * 1 on sucess and 0 on failure.
458 */
459 static int
460 hash_alloc(struct uma_hash *hash)
461 {
462 int oldsize;
463 int alloc;
464
465 oldsize = hash->uh_hashsize;
466
467 /* We're just going to go to a power of two greater */
468 if (oldsize) {
469 hash->uh_hashsize = oldsize * 2;
470 alloc = sizeof(hash->uh_slab_hash[0]) * hash->uh_hashsize;
471 hash->uh_slab_hash = (struct slabhead *)malloc(alloc,
472 M_UMAHASH, M_NOWAIT);
473 } else {
474 alloc = sizeof(hash->uh_slab_hash[0]) * UMA_HASH_SIZE_INIT;
475 hash->uh_slab_hash = uma_zalloc_internal(hashzone, NULL,
476 M_WAITOK);
477 hash->uh_hashsize = UMA_HASH_SIZE_INIT;
478 }
479 if (hash->uh_slab_hash) {
480 bzero(hash->uh_slab_hash, alloc);
481 hash->uh_hashmask = hash->uh_hashsize - 1;
482 return (1);
483 }
484
485 return (0);
486 }
487
488 /*
489 * Expands the hash table for HASH zones. This is done from zone_timeout
490 * to reduce collisions. This must not be done in the regular allocation
491 * path, otherwise, we can recurse on the vm while allocating pages.
492 *
493 * Arguments:
494 * oldhash The hash you want to expand
495 * newhash The hash structure for the new table
496 *
497 * Returns:
498 * Nothing
499 *
500 * Discussion:
501 */
502 static int
503 hash_expand(struct uma_hash *oldhash, struct uma_hash *newhash)
504 {
505 uma_slab_t slab;
506 int hval;
507 int i;
508
509 if (!newhash->uh_slab_hash)
510 return (0);
511
512 if (oldhash->uh_hashsize >= newhash->uh_hashsize)
513 return (0);
514
515 /*
516 * I need to investigate hash algorithms for resizing without a
517 * full rehash.
518 */
519
520 for (i = 0; i < oldhash->uh_hashsize; i++)
521 while (!SLIST_EMPTY(&oldhash->uh_slab_hash[i])) {
522 slab = SLIST_FIRST(&oldhash->uh_slab_hash[i]);
523 SLIST_REMOVE_HEAD(&oldhash->uh_slab_hash[i], us_hlink);
524 hval = UMA_HASH(newhash, slab->us_data);
525 SLIST_INSERT_HEAD(&newhash->uh_slab_hash[hval],
526 slab, us_hlink);
527 }
528
529 return (1);
530 }
531
532 /*
533 * Free the hash bucket to the appropriate backing store.
534 *
535 * Arguments:
536 * slab_hash The hash bucket we're freeing
537 * hashsize The number of entries in that hash bucket
538 *
539 * Returns:
540 * Nothing
541 */
542 static void
543 hash_free(struct uma_hash *hash)
544 {
545 if (hash->uh_slab_hash == NULL)
546 return;
547 if (hash->uh_hashsize == UMA_HASH_SIZE_INIT)
548 uma_zfree_internal(hashzone,
549 hash->uh_slab_hash, NULL, SKIP_NONE, ZFREE_STATFREE);
550 else
551 free(hash->uh_slab_hash, M_UMAHASH);
552 }
553
554 /*
555 * Frees all outstanding items in a bucket
556 *
557 * Arguments:
558 * zone The zone to free to, must be unlocked.
559 * bucket The free/alloc bucket with items, cpu queue must be locked.
560 *
561 * Returns:
562 * Nothing
563 */
564
565 static void
566 bucket_drain(uma_zone_t zone, uma_bucket_t bucket)
567 {
568 uma_slab_t slab;
569 int mzone;
570 void *item;
571
572 if (bucket == NULL)
573 return;
574
575 slab = NULL;
576 mzone = 0;
577
578 /* We have to lookup the slab again for malloc.. */
579 if (zone->uz_keg->uk_flags & UMA_ZONE_MALLOC)
580 mzone = 1;
581
582 while (bucket->ub_cnt > 0) {
583 bucket->ub_cnt--;
584 item = bucket->ub_bucket[bucket->ub_cnt];
585 #ifdef INVARIANTS
586 bucket->ub_bucket[bucket->ub_cnt] = NULL;
587 KASSERT(item != NULL,
588 ("bucket_drain: botched ptr, item is NULL"));
589 #endif
590 /*
591 * This is extremely inefficient. The slab pointer was passed
592 * to uma_zfree_arg, but we lost it because the buckets don't
593 * hold them. This will go away when free() gets a size passed
594 * to it.
595 */
596 if (mzone)
597 slab = vtoslab((vm_offset_t)item & (~UMA_SLAB_MASK));
598 uma_zfree_internal(zone, item, slab, SKIP_DTOR, 0);
599 }
600 }
601
602 /*
603 * Drains the per cpu caches for a zone.
604 *
605 * NOTE: This may only be called while the zone is being turn down, and not
606 * during normal operation. This is necessary in order that we do not have
607 * to migrate CPUs to drain the per-CPU caches.
608 *
609 * Arguments:
610 * zone The zone to drain, must be unlocked.
611 *
612 * Returns:
613 * Nothing
614 */
615 static void
616 cache_drain(uma_zone_t zone)
617 {
618 uma_cache_t cache;
619 int cpu;
620
621 /*
622 * XXX: It is safe to not lock the per-CPU caches, because we're
623 * tearing down the zone anyway. I.e., there will be no further use
624 * of the caches at this point.
625 *
626 * XXX: It would good to be able to assert that the zone is being
627 * torn down to prevent improper use of cache_drain().
628 *
629 * XXX: We lock the zone before passing into bucket_cache_drain() as
630 * it is used elsewhere. Should the tear-down path be made special
631 * there in some form?
632 */
633 for (cpu = 0; cpu <= mp_maxid; cpu++) {
634 if (CPU_ABSENT(cpu))
635 continue;
636 cache = &zone->uz_cpu[cpu];
637 bucket_drain(zone, cache->uc_allocbucket);
638 bucket_drain(zone, cache->uc_freebucket);
639 if (cache->uc_allocbucket != NULL)
640 bucket_free(cache->uc_allocbucket);
641 if (cache->uc_freebucket != NULL)
642 bucket_free(cache->uc_freebucket);
643 cache->uc_allocbucket = cache->uc_freebucket = NULL;
644 }
645 ZONE_LOCK(zone);
646 bucket_cache_drain(zone);
647 ZONE_UNLOCK(zone);
648 }
649
650 /*
651 * Drain the cached buckets from a zone. Expects a locked zone on entry.
652 */
653 static void
654 bucket_cache_drain(uma_zone_t zone)
655 {
656 uma_bucket_t bucket;
657
658 /*
659 * Drain the bucket queues and free the buckets, we just keep two per
660 * cpu (alloc/free).
661 */
662 while ((bucket = LIST_FIRST(&zone->uz_full_bucket)) != NULL) {
663 LIST_REMOVE(bucket, ub_link);
664 ZONE_UNLOCK(zone);
665 bucket_drain(zone, bucket);
666 bucket_free(bucket);
667 ZONE_LOCK(zone);
668 }
669
670 /* Now we do the free queue.. */
671 while ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) {
672 LIST_REMOVE(bucket, ub_link);
673 bucket_free(bucket);
674 }
675 }
676
677 /*
678 * Frees pages from a zone back to the system. This is done on demand from
679 * the pageout daemon.
680 *
681 * Arguments:
682 * zone The zone to free pages from
683 * all Should we drain all items?
684 *
685 * Returns:
686 * Nothing.
687 */
688 static void
689 zone_drain(uma_zone_t zone)
690 {
691 struct slabhead freeslabs = { 0 };
692 uma_keg_t keg;
693 uma_slab_t slab;
694 uma_slab_t n;
695 u_int8_t flags;
696 u_int8_t *mem;
697 int i;
698
699 keg = zone->uz_keg;
700
701 /*
702 * We don't want to take pages from statically allocated zones at this
703 * time
704 */
705 if (keg->uk_flags & UMA_ZONE_NOFREE || keg->uk_freef == NULL)
706 return;
707
708 ZONE_LOCK(zone);
709
710 #ifdef UMA_DEBUG
711 printf("%s free items: %u\n", zone->uz_name, keg->uk_free);
712 #endif
713 bucket_cache_drain(zone);
714 if (keg->uk_free == 0)
715 goto finished;
716
717 slab = LIST_FIRST(&keg->uk_free_slab);
718 while (slab) {
719 n = LIST_NEXT(slab, us_link);
720
721 /* We have no where to free these to */
722 if (slab->us_flags & UMA_SLAB_BOOT) {
723 slab = n;
724 continue;
725 }
726
727 LIST_REMOVE(slab, us_link);
728 keg->uk_pages -= keg->uk_ppera;
729 keg->uk_free -= keg->uk_ipers;
730
731 if (keg->uk_flags & UMA_ZONE_HASH)
732 UMA_HASH_REMOVE(&keg->uk_hash, slab, slab->us_data);
733
734 SLIST_INSERT_HEAD(&freeslabs, slab, us_hlink);
735
736 slab = n;
737 }
738 finished:
739 ZONE_UNLOCK(zone);
740
741 while ((slab = SLIST_FIRST(&freeslabs)) != NULL) {
742 SLIST_REMOVE(&freeslabs, slab, uma_slab, us_hlink);
743 if (keg->uk_fini)
744 for (i = 0; i < keg->uk_ipers; i++)
745 keg->uk_fini(
746 slab->us_data + (keg->uk_rsize * i),
747 keg->uk_size);
748 flags = slab->us_flags;
749 mem = slab->us_data;
750
751 if ((keg->uk_flags & UMA_ZONE_MALLOC) ||
752 (keg->uk_flags & UMA_ZONE_REFCNT)) {
753 vm_object_t obj;
754
755 if (flags & UMA_SLAB_KMEM)
756 obj = kmem_object;
757 else
758 obj = NULL;
759 for (i = 0; i < keg->uk_ppera; i++)
760 vsetobj((vm_offset_t)mem + (i * PAGE_SIZE),
761 obj);
762 }
763 if (keg->uk_flags & UMA_ZONE_OFFPAGE)
764 uma_zfree_internal(keg->uk_slabzone, slab, NULL,
765 SKIP_NONE, ZFREE_STATFREE);
766 #ifdef UMA_DEBUG
767 printf("%s: Returning %d bytes.\n",
768 zone->uz_name, UMA_SLAB_SIZE * keg->uk_ppera);
769 #endif
770 keg->uk_freef(mem, UMA_SLAB_SIZE * keg->uk_ppera, flags);
771 }
772 }
773
774 /*
775 * Allocate a new slab for a zone. This does not insert the slab onto a list.
776 *
777 * Arguments:
778 * zone The zone to allocate slabs for
779 * wait Shall we wait?
780 *
781 * Returns:
782 * The slab that was allocated or NULL if there is no memory and the
783 * caller specified M_NOWAIT.
784 */
785 static uma_slab_t
786 slab_zalloc(uma_zone_t zone, int wait)
787 {
788 uma_slabrefcnt_t slabref;
789 uma_slab_t slab;
790 uma_keg_t keg;
791 u_int8_t *mem;
792 u_int8_t flags;
793 int i;
794
795 slab = NULL;
796 keg = zone->uz_keg;
797
798 #ifdef UMA_DEBUG
799 printf("slab_zalloc: Allocating a new slab for %s\n", zone->uz_name);
800 #endif
801 ZONE_UNLOCK(zone);
802
803 if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
804 slab = uma_zalloc_internal(keg->uk_slabzone, NULL, wait);
805 if (slab == NULL) {
806 ZONE_LOCK(zone);
807 return NULL;
808 }
809 }
810
811 /*
812 * This reproduces the old vm_zone behavior of zero filling pages the
813 * first time they are added to a zone.
814 *
815 * Malloced items are zeroed in uma_zalloc.
816 */
817
818 if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
819 wait |= M_ZERO;
820 else
821 wait &= ~M_ZERO;
822
823 mem = keg->uk_allocf(zone, keg->uk_ppera * UMA_SLAB_SIZE,
824 &flags, wait);
825 if (mem == NULL) {
826 if (keg->uk_flags & UMA_ZONE_OFFPAGE)
827 uma_zfree_internal(keg->uk_slabzone, slab, NULL,
828 SKIP_NONE, ZFREE_STATFREE);
829 ZONE_LOCK(zone);
830 return (NULL);
831 }
832
833 /* Point the slab into the allocated memory */
834 if (!(keg->uk_flags & UMA_ZONE_OFFPAGE))
835 slab = (uma_slab_t )(mem + keg->uk_pgoff);
836
837 if ((keg->uk_flags & UMA_ZONE_MALLOC) ||
838 (keg->uk_flags & UMA_ZONE_REFCNT))
839 for (i = 0; i < keg->uk_ppera; i++)
840 vsetslab((vm_offset_t)mem + (i * PAGE_SIZE), slab);
841
842 slab->us_keg = keg;
843 slab->us_data = mem;
844 slab->us_freecount = keg->uk_ipers;
845 slab->us_firstfree = 0;
846 slab->us_flags = flags;
847
848 if (keg->uk_flags & UMA_ZONE_REFCNT) {
849 slabref = (uma_slabrefcnt_t)slab;
850 for (i = 0; i < keg->uk_ipers; i++) {
851 slabref->us_freelist[i].us_refcnt = 0;
852 slabref->us_freelist[i].us_item = i+1;
853 }
854 } else {
855 for (i = 0; i < keg->uk_ipers; i++)
856 slab->us_freelist[i].us_item = i+1;
857 }
858
859 if (keg->uk_init != NULL) {
860 for (i = 0; i < keg->uk_ipers; i++)
861 if (keg->uk_init(slab->us_data + (keg->uk_rsize * i),
862 keg->uk_size, wait) != 0)
863 break;
864 if (i != keg->uk_ipers) {
865 if (keg->uk_fini != NULL) {
866 for (i--; i > -1; i--)
867 keg->uk_fini(slab->us_data +
868 (keg->uk_rsize * i),
869 keg->uk_size);
870 }
871 if ((keg->uk_flags & UMA_ZONE_MALLOC) ||
872 (keg->uk_flags & UMA_ZONE_REFCNT)) {
873 vm_object_t obj;
874
875 if (flags & UMA_SLAB_KMEM)
876 obj = kmem_object;
877 else
878 obj = NULL;
879 for (i = 0; i < keg->uk_ppera; i++)
880 vsetobj((vm_offset_t)mem +
881 (i * PAGE_SIZE), obj);
882 }
883 if (keg->uk_flags & UMA_ZONE_OFFPAGE)
884 uma_zfree_internal(keg->uk_slabzone, slab,
885 NULL, SKIP_NONE, ZFREE_STATFREE);
886 keg->uk_freef(mem, UMA_SLAB_SIZE * keg->uk_ppera,
887 flags);
888 ZONE_LOCK(zone);
889 return (NULL);
890 }
891 }
892 ZONE_LOCK(zone);
893
894 if (keg->uk_flags & UMA_ZONE_HASH)
895 UMA_HASH_INSERT(&keg->uk_hash, slab, mem);
896
897 keg->uk_pages += keg->uk_ppera;
898 keg->uk_free += keg->uk_ipers;
899
900 return (slab);
901 }
902
903 /*
904 * This function is intended to be used early on in place of page_alloc() so
905 * that we may use the boot time page cache to satisfy allocations before
906 * the VM is ready.
907 */
908 static void *
909 startup_alloc(uma_zone_t zone, int bytes, u_int8_t *pflag, int wait)
910 {
911 uma_keg_t keg;
912 uma_slab_t tmps;
913
914 keg = zone->uz_keg;
915
916 /*
917 * Check our small startup cache to see if it has pages remaining.
918 */
919 mtx_lock(&uma_boot_pages_mtx);
920 if ((tmps = LIST_FIRST(&uma_boot_pages)) != NULL) {
921 LIST_REMOVE(tmps, us_link);
922 mtx_unlock(&uma_boot_pages_mtx);
923 *pflag = tmps->us_flags;
924 return (tmps->us_data);
925 }
926 mtx_unlock(&uma_boot_pages_mtx);
927 if (booted == 0)
928 panic("UMA: Increase vm.boot_pages");
929 /*
930 * Now that we've booted reset these users to their real allocator.
931 */
932 #ifdef UMA_MD_SMALL_ALLOC
933 keg->uk_allocf = uma_small_alloc;
934 #else
935 keg->uk_allocf = page_alloc;
936 #endif
937 return keg->uk_allocf(zone, bytes, pflag, wait);
938 }
939
940 /*
941 * Allocates a number of pages from the system
942 *
943 * Arguments:
944 * zone Unused
945 * bytes The number of bytes requested
946 * wait Shall we wait?
947 *
948 * Returns:
949 * A pointer to the alloced memory or possibly
950 * NULL if M_NOWAIT is set.
951 */
952 static void *
953 page_alloc(uma_zone_t zone, int bytes, u_int8_t *pflag, int wait)
954 {
955 void *p; /* Returned page */
956
957 *pflag = UMA_SLAB_KMEM;
958 p = (void *) kmem_malloc(kmem_map, bytes, wait);
959
960 return (p);
961 }
962
963 /*
964 * Allocates a number of pages from within an object
965 *
966 * Arguments:
967 * zone Unused
968 * bytes The number of bytes requested
969 * wait Shall we wait?
970 *
971 * Returns:
972 * A pointer to the alloced memory or possibly
973 * NULL if M_NOWAIT is set.
974 */
975 static void *
976 obj_alloc(uma_zone_t zone, int bytes, u_int8_t *flags, int wait)
977 {
978 vm_object_t object;
979 vm_offset_t retkva, zkva;
980 vm_page_t p;
981 int pages, startpages;
982
983 object = zone->uz_keg->uk_obj;
984 retkva = 0;
985
986 /*
987 * This looks a little weird since we're getting one page at a time.
988 */
989 VM_OBJECT_LOCK(object);
990 p = TAILQ_LAST(&object->memq, pglist);
991 pages = p != NULL ? p->pindex + 1 : 0;
992 startpages = pages;
993 zkva = zone->uz_keg->uk_kva + pages * PAGE_SIZE;
994 for (; bytes > 0; bytes -= PAGE_SIZE) {
995 p = vm_page_alloc(object, pages,
996 VM_ALLOC_INTERRUPT | VM_ALLOC_WIRED);
997 if (p == NULL) {
998 if (pages != startpages)
999 pmap_qremove(retkva, pages - startpages);
1000 while (pages != startpages) {
1001 pages--;
1002 p = TAILQ_LAST(&object->memq, pglist);
1003 vm_page_lock_queues();
1004 vm_page_unwire(p, 0);
1005 vm_page_free(p);
1006 vm_page_unlock_queues();
1007 }
1008 retkva = 0;
1009 goto done;
1010 }
1011 pmap_qenter(zkva, &p, 1);
1012 if (retkva == 0)
1013 retkva = zkva;
1014 zkva += PAGE_SIZE;
1015 pages += 1;
1016 }
1017 done:
1018 VM_OBJECT_UNLOCK(object);
1019 *flags = UMA_SLAB_PRIV;
1020
1021 return ((void *)retkva);
1022 }
1023
1024 /*
1025 * Frees a number of pages to the system
1026 *
1027 * Arguments:
1028 * mem A pointer to the memory to be freed
1029 * size The size of the memory being freed
1030 * flags The original p->us_flags field
1031 *
1032 * Returns:
1033 * Nothing
1034 */
1035 static void
1036 page_free(void *mem, int size, u_int8_t flags)
1037 {
1038 vm_map_t map;
1039
1040 if (flags & UMA_SLAB_KMEM)
1041 map = kmem_map;
1042 else
1043 panic("UMA: page_free used with invalid flags %d\n", flags);
1044
1045 kmem_free(map, (vm_offset_t)mem, size);
1046 }
1047
1048 /*
1049 * Zero fill initializer
1050 *
1051 * Arguments/Returns follow uma_init specifications
1052 */
1053 static int
1054 zero_init(void *mem, int size, int flags)
1055 {
1056 bzero(mem, size);
1057 return (0);
1058 }
1059
1060 /*
1061 * Finish creating a small uma zone. This calculates ipers, and the zone size.
1062 *
1063 * Arguments
1064 * zone The zone we should initialize
1065 *
1066 * Returns
1067 * Nothing
1068 */
1069 static void
1070 zone_small_init(uma_zone_t zone)
1071 {
1072 uma_keg_t keg;
1073 u_int rsize;
1074 u_int memused;
1075 u_int wastedspace;
1076 u_int shsize;
1077
1078 keg = zone->uz_keg;
1079 KASSERT(keg != NULL, ("Keg is null in zone_small_init"));
1080 rsize = keg->uk_size;
1081
1082 if (rsize < UMA_SMALLEST_UNIT)
1083 rsize = UMA_SMALLEST_UNIT;
1084 if (rsize & keg->uk_align)
1085 rsize = (rsize & ~keg->uk_align) + (keg->uk_align + 1);
1086
1087 keg->uk_rsize = rsize;
1088 keg->uk_ppera = 1;
1089
1090 if (keg->uk_flags & UMA_ZONE_REFCNT) {
1091 rsize += UMA_FRITMREF_SZ; /* linkage & refcnt */
1092 shsize = sizeof(struct uma_slab_refcnt);
1093 } else {
1094 rsize += UMA_FRITM_SZ; /* Account for linkage */
1095 shsize = sizeof(struct uma_slab);
1096 }
1097
1098 keg->uk_ipers = (UMA_SLAB_SIZE - shsize) / rsize;
1099 KASSERT(keg->uk_ipers != 0, ("zone_small_init: ipers is 0"));
1100 memused = keg->uk_ipers * rsize + shsize;
1101 wastedspace = UMA_SLAB_SIZE - memused;
1102
1103 /*
1104 * We can't do OFFPAGE if we're internal or if we've been
1105 * asked to not go to the VM for buckets. If we do this we
1106 * may end up going to the VM (kmem_map) for slabs which we
1107 * do not want to do if we're UMA_ZFLAG_CACHEONLY as a
1108 * result of UMA_ZONE_VM, which clearly forbids it.
1109 */
1110 if ((keg->uk_flags & UMA_ZFLAG_INTERNAL) ||
1111 (keg->uk_flags & UMA_ZFLAG_CACHEONLY))
1112 return;
1113
1114 if ((wastedspace >= UMA_MAX_WASTE) &&
1115 (keg->uk_ipers < (UMA_SLAB_SIZE / keg->uk_rsize))) {
1116 keg->uk_ipers = UMA_SLAB_SIZE / keg->uk_rsize;
1117 KASSERT(keg->uk_ipers <= 255,
1118 ("zone_small_init: keg->uk_ipers too high!"));
1119 #ifdef UMA_DEBUG
1120 printf("UMA decided we need offpage slab headers for "
1121 "zone: %s, calculated wastedspace = %d, "
1122 "maximum wasted space allowed = %d, "
1123 "calculated ipers = %d, "
1124 "new wasted space = %d\n", zone->uz_name, wastedspace,
1125 UMA_MAX_WASTE, keg->uk_ipers,
1126 UMA_SLAB_SIZE - keg->uk_ipers * keg->uk_rsize);
1127 #endif
1128 keg->uk_flags |= UMA_ZONE_OFFPAGE;
1129 if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
1130 keg->uk_flags |= UMA_ZONE_HASH;
1131 }
1132 }
1133
1134 /*
1135 * Finish creating a large (> UMA_SLAB_SIZE) uma zone. Just give in and do
1136 * OFFPAGE for now. When I can allow for more dynamic slab sizes this will be
1137 * more complicated.
1138 *
1139 * Arguments
1140 * zone The zone we should initialize
1141 *
1142 * Returns
1143 * Nothing
1144 */
1145 static void
1146 zone_large_init(uma_zone_t zone)
1147 {
1148 uma_keg_t keg;
1149 int pages;
1150
1151 keg = zone->uz_keg;
1152
1153 KASSERT(keg != NULL, ("Keg is null in zone_large_init"));
1154 KASSERT((keg->uk_flags & UMA_ZFLAG_CACHEONLY) == 0,
1155 ("zone_large_init: Cannot large-init a UMA_ZFLAG_CACHEONLY zone"));
1156
1157 pages = keg->uk_size / UMA_SLAB_SIZE;
1158
1159 /* Account for remainder */
1160 if ((pages * UMA_SLAB_SIZE) < keg->uk_size)
1161 pages++;
1162
1163 keg->uk_ppera = pages;
1164 keg->uk_ipers = 1;
1165
1166 keg->uk_flags |= UMA_ZONE_OFFPAGE;
1167 if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
1168 keg->uk_flags |= UMA_ZONE_HASH;
1169
1170 keg->uk_rsize = keg->uk_size;
1171 }
1172
1173 /*
1174 * Keg header ctor. This initializes all fields, locks, etc. And inserts
1175 * the keg onto the global keg list.
1176 *
1177 * Arguments/Returns follow uma_ctor specifications
1178 * udata Actually uma_kctor_args
1179 */
1180 static int
1181 keg_ctor(void *mem, int size, void *udata, int flags)
1182 {
1183 struct uma_kctor_args *arg = udata;
1184 uma_keg_t keg = mem;
1185 uma_zone_t zone;
1186
1187 bzero(keg, size);
1188 keg->uk_size = arg->size;
1189 keg->uk_init = arg->uminit;
1190 keg->uk_fini = arg->fini;
1191 keg->uk_align = arg->align;
1192 keg->uk_free = 0;
1193 keg->uk_pages = 0;
1194 keg->uk_flags = arg->flags;
1195 keg->uk_allocf = page_alloc;
1196 keg->uk_freef = page_free;
1197 keg->uk_recurse = 0;
1198 keg->uk_slabzone = NULL;
1199
1200 /*
1201 * The master zone is passed to us at keg-creation time.
1202 */
1203 zone = arg->zone;
1204 zone->uz_keg = keg;
1205
1206 if (arg->flags & UMA_ZONE_VM)
1207 keg->uk_flags |= UMA_ZFLAG_CACHEONLY;
1208
1209 if (arg->flags & UMA_ZONE_ZINIT)
1210 keg->uk_init = zero_init;
1211
1212 /*
1213 * The +UMA_FRITM_SZ added to uk_size is to account for the
1214 * linkage that is added to the size in zone_small_init(). If
1215 * we don't account for this here then we may end up in
1216 * zone_small_init() with a calculated 'ipers' of 0.
1217 */
1218 if (keg->uk_flags & UMA_ZONE_REFCNT) {
1219 if ((keg->uk_size+UMA_FRITMREF_SZ) >
1220 (UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt)))
1221 zone_large_init(zone);
1222 else
1223 zone_small_init(zone);
1224 } else {
1225 if ((keg->uk_size+UMA_FRITM_SZ) >
1226 (UMA_SLAB_SIZE - sizeof(struct uma_slab)))
1227 zone_large_init(zone);
1228 else
1229 zone_small_init(zone);
1230 }
1231
1232 if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
1233 if (keg->uk_flags & UMA_ZONE_REFCNT)
1234 keg->uk_slabzone = slabrefzone;
1235 else
1236 keg->uk_slabzone = slabzone;
1237 }
1238
1239 /*
1240 * If we haven't booted yet we need allocations to go through the
1241 * startup cache until the vm is ready.
1242 */
1243 if (keg->uk_ppera == 1) {
1244 #ifdef UMA_MD_SMALL_ALLOC
1245 keg->uk_allocf = uma_small_alloc;
1246 keg->uk_freef = uma_small_free;
1247 #endif
1248 if (booted == 0)
1249 keg->uk_allocf = startup_alloc;
1250 }
1251
1252 /*
1253 * Initialize keg's lock (shared among zones) through
1254 * Master zone
1255 */
1256 zone->uz_lock = &keg->uk_lock;
1257 if (arg->flags & UMA_ZONE_MTXCLASS)
1258 ZONE_LOCK_INIT(zone, 1);
1259 else
1260 ZONE_LOCK_INIT(zone, 0);
1261
1262 /*
1263 * If we're putting the slab header in the actual page we need to
1264 * figure out where in each page it goes. This calculates a right
1265 * justified offset into the memory on an ALIGN_PTR boundary.
1266 */
1267 if (!(keg->uk_flags & UMA_ZONE_OFFPAGE)) {
1268 u_int totsize;
1269
1270 /* Size of the slab struct and free list */
1271 if (keg->uk_flags & UMA_ZONE_REFCNT)
1272 totsize = sizeof(struct uma_slab_refcnt) +
1273 keg->uk_ipers * UMA_FRITMREF_SZ;
1274 else
1275 totsize = sizeof(struct uma_slab) +
1276 keg->uk_ipers * UMA_FRITM_SZ;
1277
1278 if (totsize & UMA_ALIGN_PTR)
1279 totsize = (totsize & ~UMA_ALIGN_PTR) +
1280 (UMA_ALIGN_PTR + 1);
1281 keg->uk_pgoff = UMA_SLAB_SIZE - totsize;
1282
1283 if (keg->uk_flags & UMA_ZONE_REFCNT)
1284 totsize = keg->uk_pgoff + sizeof(struct uma_slab_refcnt)
1285 + keg->uk_ipers * UMA_FRITMREF_SZ;
1286 else
1287 totsize = keg->uk_pgoff + sizeof(struct uma_slab)
1288 + keg->uk_ipers * UMA_FRITM_SZ;
1289
1290 /*
1291 * The only way the following is possible is if with our
1292 * UMA_ALIGN_PTR adjustments we are now bigger than
1293 * UMA_SLAB_SIZE. I haven't checked whether this is
1294 * mathematically possible for all cases, so we make
1295 * sure here anyway.
1296 */
1297 if (totsize > UMA_SLAB_SIZE) {
1298 printf("zone %s ipers %d rsize %d size %d\n",
1299 zone->uz_name, keg->uk_ipers, keg->uk_rsize,
1300 keg->uk_size);
1301 panic("UMA slab won't fit.\n");
1302 }
1303 }
1304
1305 if (keg->uk_flags & UMA_ZONE_HASH)
1306 hash_alloc(&keg->uk_hash);
1307
1308 #ifdef UMA_DEBUG
1309 printf("%s(%p) size = %d ipers = %d ppera = %d pgoff = %d\n",
1310 zone->uz_name, zone,
1311 keg->uk_size, keg->uk_ipers,
1312 keg->uk_ppera, keg->uk_pgoff);
1313 #endif
1314
1315 LIST_INSERT_HEAD(&keg->uk_zones, zone, uz_link);
1316
1317 mtx_lock(&uma_mtx);
1318 LIST_INSERT_HEAD(&uma_kegs, keg, uk_link);
1319 mtx_unlock(&uma_mtx);
1320 return (0);
1321 }
1322
1323 /*
1324 * Zone header ctor. This initializes all fields, locks, etc.
1325 *
1326 * Arguments/Returns follow uma_ctor specifications
1327 * udata Actually uma_zctor_args
1328 */
1329
1330 static int
1331 zone_ctor(void *mem, int size, void *udata, int flags)
1332 {
1333 struct uma_zctor_args *arg = udata;
1334 uma_zone_t zone = mem;
1335 uma_zone_t z;
1336 uma_keg_t keg;
1337
1338 bzero(zone, size);
1339 zone->uz_name = arg->name;
1340 zone->uz_ctor = arg->ctor;
1341 zone->uz_dtor = arg->dtor;
1342 zone->uz_init = NULL;
1343 zone->uz_fini = NULL;
1344 zone->uz_allocs = 0;
1345 zone->uz_frees = 0;
1346 zone->uz_fails = 0;
1347 zone->uz_fills = zone->uz_count = 0;
1348
1349 if (arg->flags & UMA_ZONE_SECONDARY) {
1350 KASSERT(arg->keg != NULL, ("Secondary zone on zero'd keg"));
1351 keg = arg->keg;
1352 zone->uz_keg = keg;
1353 zone->uz_init = arg->uminit;
1354 zone->uz_fini = arg->fini;
1355 zone->uz_lock = &keg->uk_lock;
1356 mtx_lock(&uma_mtx);
1357 ZONE_LOCK(zone);
1358 keg->uk_flags |= UMA_ZONE_SECONDARY;
1359 LIST_FOREACH(z, &keg->uk_zones, uz_link) {
1360 if (LIST_NEXT(z, uz_link) == NULL) {
1361 LIST_INSERT_AFTER(z, zone, uz_link);
1362 break;
1363 }
1364 }
1365 ZONE_UNLOCK(zone);
1366 mtx_unlock(&uma_mtx);
1367 } else if (arg->keg == NULL) {
1368 if (uma_kcreate(zone, arg->size, arg->uminit, arg->fini,
1369 arg->align, arg->flags) == NULL)
1370 return (ENOMEM);
1371 } else {
1372 struct uma_kctor_args karg;
1373 int error;
1374
1375 /* We should only be here from uma_startup() */
1376 karg.size = arg->size;
1377 karg.uminit = arg->uminit;
1378 karg.fini = arg->fini;
1379 karg.align = arg->align;
1380 karg.flags = arg->flags;
1381 karg.zone = zone;
1382 error = keg_ctor(arg->keg, sizeof(struct uma_keg), &karg,
1383 flags);
1384 if (error)
1385 return (error);
1386 }
1387 keg = zone->uz_keg;
1388 zone->uz_lock = &keg->uk_lock;
1389
1390 /*
1391 * Some internal zones don't have room allocated for the per cpu
1392 * caches. If we're internal, bail out here.
1393 */
1394 if (keg->uk_flags & UMA_ZFLAG_INTERNAL) {
1395 KASSERT((keg->uk_flags & UMA_ZONE_SECONDARY) == 0,
1396 ("Secondary zone requested UMA_ZFLAG_INTERNAL"));
1397 return (0);
1398 }
1399
1400 if (keg->uk_flags & UMA_ZONE_MAXBUCKET)
1401 zone->uz_count = BUCKET_MAX;
1402 else if (keg->uk_ipers <= BUCKET_MAX)
1403 zone->uz_count = keg->uk_ipers;
1404 else
1405 zone->uz_count = BUCKET_MAX;
1406 return (0);
1407 }
1408
1409 /*
1410 * Keg header dtor. This frees all data, destroys locks, frees the hash
1411 * table and removes the keg from the global list.
1412 *
1413 * Arguments/Returns follow uma_dtor specifications
1414 * udata unused
1415 */
1416 static void
1417 keg_dtor(void *arg, int size, void *udata)
1418 {
1419 uma_keg_t keg;
1420
1421 keg = (uma_keg_t)arg;
1422 mtx_lock(&keg->uk_lock);
1423 if (keg->uk_free != 0) {
1424 printf("Freed UMA keg was not empty (%d items). "
1425 " Lost %d pages of memory.\n",
1426 keg->uk_free, keg->uk_pages);
1427 }
1428 mtx_unlock(&keg->uk_lock);
1429
1430 if (keg->uk_flags & UMA_ZONE_HASH)
1431 hash_free(&keg->uk_hash);
1432
1433 mtx_destroy(&keg->uk_lock);
1434 }
1435
1436 /*
1437 * Zone header dtor.
1438 *
1439 * Arguments/Returns follow uma_dtor specifications
1440 * udata unused
1441 */
1442 static void
1443 zone_dtor(void *arg, int size, void *udata)
1444 {
1445 uma_zone_t zone;
1446 uma_keg_t keg;
1447
1448 zone = (uma_zone_t)arg;
1449 keg = zone->uz_keg;
1450
1451 if (!(keg->uk_flags & UMA_ZFLAG_INTERNAL))
1452 cache_drain(zone);
1453
1454 mtx_lock(&uma_mtx);
1455 zone_drain(zone);
1456 if (keg->uk_flags & UMA_ZONE_SECONDARY) {
1457 LIST_REMOVE(zone, uz_link);
1458 /*
1459 * XXX there are some races here where
1460 * the zone can be drained but zone lock
1461 * released and then refilled before we
1462 * remove it... we dont care for now
1463 */
1464 ZONE_LOCK(zone);
1465 if (LIST_EMPTY(&keg->uk_zones))
1466 keg->uk_flags &= ~UMA_ZONE_SECONDARY;
1467 ZONE_UNLOCK(zone);
1468 mtx_unlock(&uma_mtx);
1469 } else {
1470 LIST_REMOVE(keg, uk_link);
1471 LIST_REMOVE(zone, uz_link);
1472 mtx_unlock(&uma_mtx);
1473 uma_zfree_internal(kegs, keg, NULL, SKIP_NONE,
1474 ZFREE_STATFREE);
1475 }
1476 zone->uz_keg = NULL;
1477 }
1478
1479 /*
1480 * Traverses every zone in the system and calls a callback
1481 *
1482 * Arguments:
1483 * zfunc A pointer to a function which accepts a zone
1484 * as an argument.
1485 *
1486 * Returns:
1487 * Nothing
1488 */
1489 static void
1490 zone_foreach(void (*zfunc)(uma_zone_t))
1491 {
1492 uma_keg_t keg;
1493 uma_zone_t zone;
1494
1495 mtx_lock(&uma_mtx);
1496 LIST_FOREACH(keg, &uma_kegs, uk_link) {
1497 LIST_FOREACH(zone, &keg->uk_zones, uz_link)
1498 zfunc(zone);
1499 }
1500 mtx_unlock(&uma_mtx);
1501 }
1502
1503 /* Public functions */
1504 /* See uma.h */
1505 void
1506 uma_startup(void *bootmem, int boot_pages)
1507 {
1508 struct uma_zctor_args args;
1509 uma_slab_t slab;
1510 u_int slabsize;
1511 u_int objsize, totsize, wsize;
1512 int i;
1513
1514 #ifdef UMA_DEBUG
1515 printf("Creating uma keg headers zone and keg.\n");
1516 #endif
1517 mtx_init(&uma_mtx, "UMA lock", NULL, MTX_DEF);
1518
1519 /*
1520 * Figure out the maximum number of items-per-slab we'll have if
1521 * we're using the OFFPAGE slab header to track free items, given
1522 * all possible object sizes and the maximum desired wastage
1523 * (UMA_MAX_WASTE).
1524 *
1525 * We iterate until we find an object size for
1526 * which the calculated wastage in zone_small_init() will be
1527 * enough to warrant OFFPAGE. Since wastedspace versus objsize
1528 * is an overall increasing see-saw function, we find the smallest
1529 * objsize such that the wastage is always acceptable for objects
1530 * with that objsize or smaller. Since a smaller objsize always
1531 * generates a larger possible uma_max_ipers, we use this computed
1532 * objsize to calculate the largest ipers possible. Since the
1533 * ipers calculated for OFFPAGE slab headers is always larger than
1534 * the ipers initially calculated in zone_small_init(), we use
1535 * the former's equation (UMA_SLAB_SIZE / keg->uk_rsize) to
1536 * obtain the maximum ipers possible for offpage slab headers.
1537 *
1538 * It should be noted that ipers versus objsize is an inversly
1539 * proportional function which drops off rather quickly so as
1540 * long as our UMA_MAX_WASTE is such that the objsize we calculate
1541 * falls into the portion of the inverse relation AFTER the steep
1542 * falloff, then uma_max_ipers shouldn't be too high (~10 on i386).
1543 *
1544 * Note that we have 8-bits (1 byte) to use as a freelist index
1545 * inside the actual slab header itself and this is enough to
1546 * accomodate us. In the worst case, a UMA_SMALLEST_UNIT sized
1547 * object with offpage slab header would have ipers =
1548 * UMA_SLAB_SIZE / UMA_SMALLEST_UNIT (currently = 256), which is
1549 * 1 greater than what our byte-integer freelist index can
1550 * accomodate, but we know that this situation never occurs as
1551 * for UMA_SMALLEST_UNIT-sized objects, we will never calculate
1552 * that we need to go to offpage slab headers. Or, if we do,
1553 * then we trap that condition below and panic in the INVARIANTS case.
1554 */
1555 wsize = UMA_SLAB_SIZE - sizeof(struct uma_slab) - UMA_MAX_WASTE;
1556 totsize = wsize;
1557 objsize = UMA_SMALLEST_UNIT;
1558 while (totsize >= wsize) {
1559 totsize = (UMA_SLAB_SIZE - sizeof(struct uma_slab)) /
1560 (objsize + UMA_FRITM_SZ);
1561 totsize *= (UMA_FRITM_SZ + objsize);
1562 objsize++;
1563 }
1564 if (objsize > UMA_SMALLEST_UNIT)
1565 objsize--;
1566 uma_max_ipers = UMA_SLAB_SIZE / objsize;
1567
1568 wsize = UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt) - UMA_MAX_WASTE;
1569 totsize = wsize;
1570 objsize = UMA_SMALLEST_UNIT;
1571 while (totsize >= wsize) {
1572 totsize = (UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt)) /
1573 (objsize + UMA_FRITMREF_SZ);
1574 totsize *= (UMA_FRITMREF_SZ + objsize);
1575 objsize++;
1576 }
1577 if (objsize > UMA_SMALLEST_UNIT)
1578 objsize--;
1579 uma_max_ipers_ref = UMA_SLAB_SIZE / objsize;
1580
1581 KASSERT((uma_max_ipers_ref <= 255) && (uma_max_ipers <= 255),
1582 ("uma_startup: calculated uma_max_ipers values too large!"));
1583
1584 #ifdef UMA_DEBUG
1585 printf("Calculated uma_max_ipers (for OFFPAGE) is %d\n", uma_max_ipers);
1586 printf("Calculated uma_max_ipers_slab (for OFFPAGE) is %d\n",
1587 uma_max_ipers_ref);
1588 #endif
1589
1590 /* "manually" create the initial zone */
1591 args.name = "UMA Kegs";
1592 args.size = sizeof(struct uma_keg);
1593 args.ctor = keg_ctor;
1594 args.dtor = keg_dtor;
1595 args.uminit = zero_init;
1596 args.fini = NULL;
1597 args.keg = &masterkeg;
1598 args.align = 32 - 1;
1599 args.flags = UMA_ZFLAG_INTERNAL;
1600 /* The initial zone has no Per cpu queues so it's smaller */
1601 zone_ctor(kegs, sizeof(struct uma_zone), &args, M_WAITOK);
1602
1603 #ifdef UMA_DEBUG
1604 printf("Filling boot free list.\n");
1605 #endif
1606 for (i = 0; i < boot_pages; i++) {
1607 slab = (uma_slab_t)((u_int8_t *)bootmem + (i * UMA_SLAB_SIZE));
1608 slab->us_data = (u_int8_t *)slab;
1609 slab->us_flags = UMA_SLAB_BOOT;
1610 LIST_INSERT_HEAD(&uma_boot_pages, slab, us_link);
1611 }
1612 mtx_init(&uma_boot_pages_mtx, "UMA boot pages", NULL, MTX_DEF);
1613
1614 #ifdef UMA_DEBUG
1615 printf("Creating uma zone headers zone and keg.\n");
1616 #endif
1617 args.name = "UMA Zones";
1618 args.size = sizeof(struct uma_zone) +
1619 (sizeof(struct uma_cache) * (mp_maxid + 1));
1620 args.ctor = zone_ctor;
1621 args.dtor = zone_dtor;
1622 args.uminit = zero_init;
1623 args.fini = NULL;
1624 args.keg = NULL;
1625 args.align = 32 - 1;
1626 args.flags = UMA_ZFLAG_INTERNAL;
1627 /* The initial zone has no Per cpu queues so it's smaller */
1628 zone_ctor(zones, sizeof(struct uma_zone), &args, M_WAITOK);
1629
1630 #ifdef UMA_DEBUG
1631 printf("Initializing pcpu cache locks.\n");
1632 #endif
1633 #ifdef UMA_DEBUG
1634 printf("Creating slab and hash zones.\n");
1635 #endif
1636
1637 /*
1638 * This is the max number of free list items we'll have with
1639 * offpage slabs.
1640 */
1641 slabsize = uma_max_ipers * UMA_FRITM_SZ;
1642 slabsize += sizeof(struct uma_slab);
1643
1644 /* Now make a zone for slab headers */
1645 slabzone = uma_zcreate("UMA Slabs",
1646 slabsize,
1647 NULL, NULL, NULL, NULL,
1648 UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
1649
1650 /*
1651 * We also create a zone for the bigger slabs with reference
1652 * counts in them, to accomodate UMA_ZONE_REFCNT zones.
1653 */
1654 slabsize = uma_max_ipers_ref * UMA_FRITMREF_SZ;
1655 slabsize += sizeof(struct uma_slab_refcnt);
1656 slabrefzone = uma_zcreate("UMA RCntSlabs",
1657 slabsize,
1658 NULL, NULL, NULL, NULL,
1659 UMA_ALIGN_PTR,
1660 UMA_ZFLAG_INTERNAL);
1661
1662 hashzone = uma_zcreate("UMA Hash",
1663 sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT,
1664 NULL, NULL, NULL, NULL,
1665 UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
1666
1667 bucket_init();
1668
1669 #ifdef UMA_MD_SMALL_ALLOC
1670 booted = 1;
1671 #endif
1672
1673 #ifdef UMA_DEBUG
1674 printf("UMA startup complete.\n");
1675 #endif
1676 }
1677
1678 /* see uma.h */
1679 void
1680 uma_startup2(void)
1681 {
1682 booted = 1;
1683 bucket_enable();
1684 #ifdef UMA_DEBUG
1685 printf("UMA startup2 complete.\n");
1686 #endif
1687 }
1688
1689 /*
1690 * Initialize our callout handle
1691 *
1692 */
1693
1694 static void
1695 uma_startup3(void)
1696 {
1697 #ifdef UMA_DEBUG
1698 printf("Starting callout.\n");
1699 #endif
1700 callout_init(&uma_callout, CALLOUT_MPSAFE);
1701 callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
1702 #ifdef UMA_DEBUG
1703 printf("UMA startup3 complete.\n");
1704 #endif
1705 }
1706
1707 static uma_zone_t
1708 uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini,
1709 int align, u_int32_t flags)
1710 {
1711 struct uma_kctor_args args;
1712
1713 args.size = size;
1714 args.uminit = uminit;
1715 args.fini = fini;
1716 args.align = align;
1717 args.flags = flags;
1718 args.zone = zone;
1719 return (uma_zalloc_internal(kegs, &args, M_WAITOK));
1720 }
1721
1722 /* See uma.h */
1723 uma_zone_t
1724 uma_zcreate(char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
1725 uma_init uminit, uma_fini fini, int align, u_int32_t flags)
1726
1727 {
1728 struct uma_zctor_args args;
1729
1730 /* This stuff is essential for the zone ctor */
1731 args.name = name;
1732 args.size = size;
1733 args.ctor = ctor;
1734 args.dtor = dtor;
1735 args.uminit = uminit;
1736 args.fini = fini;
1737 args.align = align;
1738 args.flags = flags;
1739 args.keg = NULL;
1740
1741 return (uma_zalloc_internal(zones, &args, M_WAITOK));
1742 }
1743
1744 /* See uma.h */
1745 uma_zone_t
1746 uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
1747 uma_init zinit, uma_fini zfini, uma_zone_t master)
1748 {
1749 struct uma_zctor_args args;
1750
1751 args.name = name;
1752 args.size = master->uz_keg->uk_size;
1753 args.ctor = ctor;
1754 args.dtor = dtor;
1755 args.uminit = zinit;
1756 args.fini = zfini;
1757 args.align = master->uz_keg->uk_align;
1758 args.flags = master->uz_keg->uk_flags | UMA_ZONE_SECONDARY;
1759 args.keg = master->uz_keg;
1760
1761 return (uma_zalloc_internal(zones, &args, M_WAITOK));
1762 }
1763
1764 /* See uma.h */
1765 void
1766 uma_zdestroy(uma_zone_t zone)
1767 {
1768
1769 uma_zfree_internal(zones, zone, NULL, SKIP_NONE, ZFREE_STATFREE);
1770 }
1771
1772 /* See uma.h */
1773 void *
1774 uma_zalloc_arg(uma_zone_t zone, void *udata, int flags)
1775 {
1776 void *item;
1777 uma_cache_t cache;
1778 uma_bucket_t bucket;
1779 int cpu;
1780 int badness;
1781
1782 /* This is the fast path allocation */
1783 #ifdef UMA_DEBUG_ALLOC_1
1784 printf("Allocating one item from %s(%p)\n", zone->uz_name, zone);
1785 #endif
1786 CTR3(KTR_UMA, "uma_zalloc_arg thread %x zone %s flags %d", curthread,
1787 zone->uz_name, flags);
1788
1789 if (!(flags & M_NOWAIT)) {
1790 KASSERT(curthread->td_intr_nesting_level == 0,
1791 ("malloc(M_WAITOK) in interrupt context"));
1792 if (nosleepwithlocks) {
1793 #ifdef WITNESS
1794 badness = WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
1795 NULL,
1796 "malloc(M_WAITOK) of \"%s\", forcing M_NOWAIT",
1797 zone->uz_name);
1798 #else
1799 badness = 1;
1800 #endif
1801 } else {
1802 badness = 0;
1803 #ifdef WITNESS
1804 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
1805 "malloc(M_WAITOK) of \"%s\"", zone->uz_name);
1806 #endif
1807 }
1808 if (badness) {
1809 flags &= ~M_WAITOK;
1810 flags |= M_NOWAIT;
1811 }
1812 }
1813
1814 /*
1815 * If possible, allocate from the per-CPU cache. There are two
1816 * requirements for safe access to the per-CPU cache: (1) the thread
1817 * accessing the cache must not be preempted or yield during access,
1818 * and (2) the thread must not migrate CPUs without switching which
1819 * cache it accesses. We rely on a critical section to prevent
1820 * preemption and migration. We release the critical section in
1821 * order to acquire the zone mutex if we are unable to allocate from
1822 * the current cache; when we re-acquire the critical section, we
1823 * must detect and handle migration if it has occurred.
1824 */
1825 zalloc_restart:
1826 critical_enter();
1827 cpu = curcpu;
1828 cache = &zone->uz_cpu[cpu];
1829
1830 zalloc_start:
1831 bucket = cache->uc_allocbucket;
1832
1833 if (bucket) {
1834 if (bucket->ub_cnt > 0) {
1835 bucket->ub_cnt--;
1836 item = bucket->ub_bucket[bucket->ub_cnt];
1837 #ifdef INVARIANTS
1838 bucket->ub_bucket[bucket->ub_cnt] = NULL;
1839 #endif
1840 KASSERT(item != NULL,
1841 ("uma_zalloc: Bucket pointer mangled."));
1842 cache->uc_allocs++;
1843 critical_exit();
1844 #ifdef INVARIANTS
1845 ZONE_LOCK(zone);
1846 uma_dbg_alloc(zone, NULL, item);
1847 ZONE_UNLOCK(zone);
1848 #endif
1849 if (zone->uz_ctor != NULL) {
1850 if (zone->uz_ctor(item, zone->uz_keg->uk_size,
1851 udata, flags) != 0) {
1852 uma_zfree_internal(zone, item, udata,
1853 SKIP_DTOR, ZFREE_STATFAIL |
1854 ZFREE_STATFREE);
1855 return (NULL);
1856 }
1857 }
1858 if (flags & M_ZERO)
1859 bzero(item, zone->uz_keg->uk_size);
1860 return (item);
1861 } else if (cache->uc_freebucket) {
1862 /*
1863 * We have run out of items in our allocbucket.
1864 * See if we can switch with our free bucket.
1865 */
1866 if (cache->uc_freebucket->ub_cnt > 0) {
1867 #ifdef UMA_DEBUG_ALLOC
1868 printf("uma_zalloc: Swapping empty with"
1869 " alloc.\n");
1870 #endif
1871 bucket = cache->uc_freebucket;
1872 cache->uc_freebucket = cache->uc_allocbucket;
1873 cache->uc_allocbucket = bucket;
1874
1875 goto zalloc_start;
1876 }
1877 }
1878 }
1879 /*
1880 * Attempt to retrieve the item from the per-CPU cache has failed, so
1881 * we must go back to the zone. This requires the zone lock, so we
1882 * must drop the critical section, then re-acquire it when we go back
1883 * to the cache. Since the critical section is released, we may be
1884 * preempted or migrate. As such, make sure not to maintain any
1885 * thread-local state specific to the cache from prior to releasing
1886 * the critical section.
1887 */
1888 critical_exit();
1889 ZONE_LOCK(zone);
1890 critical_enter();
1891 cpu = curcpu;
1892 cache = &zone->uz_cpu[cpu];
1893 bucket = cache->uc_allocbucket;
1894 if (bucket != NULL) {
1895 if (bucket->ub_cnt > 0) {
1896 ZONE_UNLOCK(zone);
1897 goto zalloc_start;
1898 }
1899 bucket = cache->uc_freebucket;
1900 if (bucket != NULL && bucket->ub_cnt > 0) {
1901 ZONE_UNLOCK(zone);
1902 goto zalloc_start;
1903 }
1904 }
1905
1906 /* Since we have locked the zone we may as well send back our stats */
1907 zone->uz_allocs += cache->uc_allocs;
1908 cache->uc_allocs = 0;
1909 zone->uz_frees += cache->uc_frees;
1910 cache->uc_frees = 0;
1911
1912 /* Our old one is now a free bucket */
1913 if (cache->uc_allocbucket) {
1914 KASSERT(cache->uc_allocbucket->ub_cnt == 0,
1915 ("uma_zalloc_arg: Freeing a non free bucket."));
1916 LIST_INSERT_HEAD(&zone->uz_free_bucket,
1917 cache->uc_allocbucket, ub_link);
1918 cache->uc_allocbucket = NULL;
1919 }
1920
1921 /* Check the free list for a new alloc bucket */
1922 if ((bucket = LIST_FIRST(&zone->uz_full_bucket)) != NULL) {
1923 KASSERT(bucket->ub_cnt != 0,
1924 ("uma_zalloc_arg: Returning an empty bucket."));
1925
1926 LIST_REMOVE(bucket, ub_link);
1927 cache->uc_allocbucket = bucket;
1928 ZONE_UNLOCK(zone);
1929 goto zalloc_start;
1930 }
1931 /* We are no longer associated with this CPU. */
1932 critical_exit();
1933
1934 /* Bump up our uz_count so we get here less */
1935 if (zone->uz_count < BUCKET_MAX)
1936 zone->uz_count++;
1937
1938 /*
1939 * Now lets just fill a bucket and put it on the free list. If that
1940 * works we'll restart the allocation from the begining.
1941 */
1942 if (uma_zalloc_bucket(zone, flags)) {
1943 ZONE_UNLOCK(zone);
1944 goto zalloc_restart;
1945 }
1946 ZONE_UNLOCK(zone);
1947 /*
1948 * We may not be able to get a bucket so return an actual item.
1949 */
1950 #ifdef UMA_DEBUG
1951 printf("uma_zalloc_arg: Bucketzone returned NULL\n");
1952 #endif
1953
1954 return (uma_zalloc_internal(zone, udata, flags));
1955 }
1956
1957 static uma_slab_t
1958 uma_zone_slab(uma_zone_t zone, int flags)
1959 {
1960 uma_slab_t slab;
1961 uma_keg_t keg;
1962
1963 keg = zone->uz_keg;
1964
1965 /*
1966 * This is to prevent us from recursively trying to allocate
1967 * buckets. The problem is that if an allocation forces us to
1968 * grab a new bucket we will call page_alloc, which will go off
1969 * and cause the vm to allocate vm_map_entries. If we need new
1970 * buckets there too we will recurse in kmem_alloc and bad
1971 * things happen. So instead we return a NULL bucket, and make
1972 * the code that allocates buckets smart enough to deal with it
1973 *
1974 * XXX: While we want this protection for the bucket zones so that
1975 * recursion from the VM is handled (and the calling code that
1976 * allocates buckets knows how to deal with it), we do not want
1977 * to prevent allocation from the slab header zones (slabzone
1978 * and slabrefzone) if uk_recurse is not zero for them. The
1979 * reason is that it could lead to NULL being returned for
1980 * slab header allocations even in the M_WAITOK case, and the
1981 * caller can't handle that.
1982 */
1983 if (keg->uk_flags & UMA_ZFLAG_INTERNAL && keg->uk_recurse != 0)
1984 if ((zone != slabzone) && (zone != slabrefzone))
1985 return (NULL);
1986
1987 slab = NULL;
1988
1989 for (;;) {
1990 /*
1991 * Find a slab with some space. Prefer slabs that are partially
1992 * used over those that are totally full. This helps to reduce
1993 * fragmentation.
1994 */
1995 if (keg->uk_free != 0) {
1996 if (!LIST_EMPTY(&keg->uk_part_slab)) {
1997 slab = LIST_FIRST(&keg->uk_part_slab);
1998 } else {
1999 slab = LIST_FIRST(&keg->uk_free_slab);
2000 LIST_REMOVE(slab, us_link);
2001 LIST_INSERT_HEAD(&keg->uk_part_slab, slab,
2002 us_link);
2003 }
2004 return (slab);
2005 }
2006
2007 /*
2008 * M_NOVM means don't ask at all!
2009 */
2010 if (flags & M_NOVM)
2011 break;
2012
2013 if (keg->uk_maxpages &&
2014 keg->uk_pages >= keg->uk_maxpages) {
2015 keg->uk_flags |= UMA_ZFLAG_FULL;
2016
2017 if (flags & M_NOWAIT)
2018 break;
2019 else
2020 msleep(keg, &keg->uk_lock, PVM,
2021 "zonelimit", 0);
2022 continue;
2023 }
2024 keg->uk_recurse++;
2025 slab = slab_zalloc(zone, flags);
2026 keg->uk_recurse--;
2027
2028 /*
2029 * If we got a slab here it's safe to mark it partially used
2030 * and return. We assume that the caller is going to remove
2031 * at least one item.
2032 */
2033 if (slab) {
2034 LIST_INSERT_HEAD(&keg->uk_part_slab, slab, us_link);
2035 return (slab);
2036 }
2037 /*
2038 * We might not have been able to get a slab but another cpu
2039 * could have while we were unlocked. Check again before we
2040 * fail.
2041 */
2042 if (flags & M_NOWAIT)
2043 flags |= M_NOVM;
2044 }
2045 return (slab);
2046 }
2047
2048 static void *
2049 uma_slab_alloc(uma_zone_t zone, uma_slab_t slab)
2050 {
2051 uma_keg_t keg;
2052 uma_slabrefcnt_t slabref;
2053 void *item;
2054 u_int8_t freei;
2055
2056 keg = zone->uz_keg;
2057
2058 freei = slab->us_firstfree;
2059 if (keg->uk_flags & UMA_ZONE_REFCNT) {
2060 slabref = (uma_slabrefcnt_t)slab;
2061 slab->us_firstfree = slabref->us_freelist[freei].us_item;
2062 } else {
2063 slab->us_firstfree = slab->us_freelist[freei].us_item;
2064 }
2065 item = slab->us_data + (keg->uk_rsize * freei);
2066
2067 slab->us_freecount--;
2068 keg->uk_free--;
2069 #ifdef INVARIANTS
2070 uma_dbg_alloc(zone, slab, item);
2071 #endif
2072 /* Move this slab to the full list */
2073 if (slab->us_freecount == 0) {
2074 LIST_REMOVE(slab, us_link);
2075 LIST_INSERT_HEAD(&keg->uk_full_slab, slab, us_link);
2076 }
2077
2078 return (item);
2079 }
2080
2081 static int
2082 uma_zalloc_bucket(uma_zone_t zone, int flags)
2083 {
2084 uma_bucket_t bucket;
2085 uma_slab_t slab;
2086 int16_t saved;
2087 int max, origflags = flags;
2088
2089 /*
2090 * Try this zone's free list first so we don't allocate extra buckets.
2091 */
2092 if ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) {
2093 KASSERT(bucket->ub_cnt == 0,
2094 ("uma_zalloc_bucket: Bucket on free list is not empty."));
2095 LIST_REMOVE(bucket, ub_link);
2096 } else {
2097 int bflags;
2098
2099 bflags = (flags & ~M_ZERO);
2100 if (zone->uz_keg->uk_flags & UMA_ZFLAG_CACHEONLY)
2101 bflags |= M_NOVM;
2102
2103 ZONE_UNLOCK(zone);
2104 bucket = bucket_alloc(zone->uz_count, bflags);
2105 ZONE_LOCK(zone);
2106 }
2107
2108 if (bucket == NULL)
2109 return (0);
2110
2111 #ifdef SMP
2112 /*
2113 * This code is here to limit the number of simultaneous bucket fills
2114 * for any given zone to the number of per cpu caches in this zone. This
2115 * is done so that we don't allocate more memory than we really need.
2116 */
2117 if (zone->uz_fills >= mp_ncpus)
2118 goto done;
2119
2120 #endif
2121 zone->uz_fills++;
2122
2123 max = MIN(bucket->ub_entries, zone->uz_count);
2124 /* Try to keep the buckets totally full */
2125 saved = bucket->ub_cnt;
2126 while (bucket->ub_cnt < max &&
2127 (slab = uma_zone_slab(zone, flags)) != NULL) {
2128 while (slab->us_freecount && bucket->ub_cnt < max) {
2129 bucket->ub_bucket[bucket->ub_cnt++] =
2130 uma_slab_alloc(zone, slab);
2131 }
2132
2133 /* Don't block on the next fill */
2134 flags |= M_NOWAIT;
2135 }
2136
2137 /*
2138 * We unlock here because we need to call the zone's init.
2139 * It should be safe to unlock because the slab dealt with
2140 * above is already on the appropriate list within the keg
2141 * and the bucket we filled is not yet on any list, so we
2142 * own it.
2143 */
2144 if (zone->uz_init != NULL) {
2145 int i;
2146
2147 ZONE_UNLOCK(zone);
2148 for (i = saved; i < bucket->ub_cnt; i++)
2149 if (zone->uz_init(bucket->ub_bucket[i],
2150 zone->uz_keg->uk_size, origflags) != 0)
2151 break;
2152 /*
2153 * If we couldn't initialize the whole bucket, put the
2154 * rest back onto the freelist.
2155 */
2156 if (i != bucket->ub_cnt) {
2157 int j;
2158
2159 for (j = i; j < bucket->ub_cnt; j++) {
2160 uma_zfree_internal(zone, bucket->ub_bucket[j],
2161 NULL, SKIP_FINI, 0);
2162 #ifdef INVARIANTS
2163 bucket->ub_bucket[j] = NULL;
2164 #endif
2165 }
2166 bucket->ub_cnt = i;
2167 }
2168 ZONE_LOCK(zone);
2169 }
2170
2171 zone->uz_fills--;
2172 if (bucket->ub_cnt != 0) {
2173 LIST_INSERT_HEAD(&zone->uz_full_bucket,
2174 bucket, ub_link);
2175 return (1);
2176 }
2177 #ifdef SMP
2178 done:
2179 #endif
2180 bucket_free(bucket);
2181
2182 return (0);
2183 }
2184 /*
2185 * Allocates an item for an internal zone
2186 *
2187 * Arguments
2188 * zone The zone to alloc for.
2189 * udata The data to be passed to the constructor.
2190 * flags M_WAITOK, M_NOWAIT, M_ZERO.
2191 *
2192 * Returns
2193 * NULL if there is no memory and M_NOWAIT is set
2194 * An item if successful
2195 */
2196
2197 static void *
2198 uma_zalloc_internal(uma_zone_t zone, void *udata, int flags)
2199 {
2200 uma_keg_t keg;
2201 uma_slab_t slab;
2202 void *item;
2203
2204 item = NULL;
2205 keg = zone->uz_keg;
2206
2207 #ifdef UMA_DEBUG_ALLOC
2208 printf("INTERNAL: Allocating one item from %s(%p)\n", zone->uz_name, zone);
2209 #endif
2210 ZONE_LOCK(zone);
2211
2212 slab = uma_zone_slab(zone, flags);
2213 if (slab == NULL) {
2214 zone->uz_fails++;
2215 ZONE_UNLOCK(zone);
2216 return (NULL);
2217 }
2218
2219 item = uma_slab_alloc(zone, slab);
2220
2221 zone->uz_allocs++;
2222
2223 ZONE_UNLOCK(zone);
2224
2225 /*
2226 * We have to call both the zone's init (not the keg's init)
2227 * and the zone's ctor. This is because the item is going from
2228 * a keg slab directly to the user, and the user is expecting it
2229 * to be both zone-init'd as well as zone-ctor'd.
2230 */
2231 if (zone->uz_init != NULL) {
2232 if (zone->uz_init(item, keg->uk_size, flags) != 0) {
2233 uma_zfree_internal(zone, item, udata, SKIP_FINI,
2234 ZFREE_STATFAIL | ZFREE_STATFREE);
2235 return (NULL);
2236 }
2237 }
2238 if (zone->uz_ctor != NULL) {
2239 if (zone->uz_ctor(item, keg->uk_size, udata, flags) != 0) {
2240 uma_zfree_internal(zone, item, udata, SKIP_DTOR,
2241 ZFREE_STATFAIL | ZFREE_STATFREE);
2242 return (NULL);
2243 }
2244 }
2245 if (flags & M_ZERO)
2246 bzero(item, keg->uk_size);
2247
2248 return (item);
2249 }
2250
2251 /* See uma.h */
2252 void
2253 uma_zfree_arg(uma_zone_t zone, void *item, void *udata)
2254 {
2255 uma_keg_t keg;
2256 uma_cache_t cache;
2257 uma_bucket_t bucket;
2258 int bflags;
2259 int cpu;
2260
2261 keg = zone->uz_keg;
2262
2263 #ifdef UMA_DEBUG_ALLOC_1
2264 printf("Freeing item %p to %s(%p)\n", item, zone->uz_name, zone);
2265 #endif
2266 CTR2(KTR_UMA, "uma_zfree_arg thread %x zone %s", curthread,
2267 zone->uz_name);
2268
2269 if (zone->uz_dtor)
2270 zone->uz_dtor(item, keg->uk_size, udata);
2271 #ifdef INVARIANTS
2272 ZONE_LOCK(zone);
2273 if (keg->uk_flags & UMA_ZONE_MALLOC)
2274 uma_dbg_free(zone, udata, item);
2275 else
2276 uma_dbg_free(zone, NULL, item);
2277 ZONE_UNLOCK(zone);
2278 #endif
2279 /*
2280 * The race here is acceptable. If we miss it we'll just have to wait
2281 * a little longer for the limits to be reset.
2282 */
2283 if (keg->uk_flags & UMA_ZFLAG_FULL)
2284 goto zfree_internal;
2285
2286 /*
2287 * If possible, free to the per-CPU cache. There are two
2288 * requirements for safe access to the per-CPU cache: (1) the thread
2289 * accessing the cache must not be preempted or yield during access,
2290 * and (2) the thread must not migrate CPUs without switching which
2291 * cache it accesses. We rely on a critical section to prevent
2292 * preemption and migration. We release the critical section in
2293 * order to acquire the zone mutex if we are unable to free to the
2294 * current cache; when we re-acquire the critical section, we must
2295 * detect and handle migration if it has occurred.
2296 */
2297 zfree_restart:
2298 critical_enter();
2299 cpu = curcpu;
2300 cache = &zone->uz_cpu[cpu];
2301
2302 zfree_start:
2303 bucket = cache->uc_freebucket;
2304
2305 if (bucket) {
2306 /*
2307 * Do we have room in our bucket? It is OK for this uz count
2308 * check to be slightly out of sync.
2309 */
2310
2311 if (bucket->ub_cnt < bucket->ub_entries) {
2312 KASSERT(bucket->ub_bucket[bucket->ub_cnt] == NULL,
2313 ("uma_zfree: Freeing to non free bucket index."));
2314 bucket->ub_bucket[bucket->ub_cnt] = item;
2315 bucket->ub_cnt++;
2316 cache->uc_frees++;
2317 critical_exit();
2318 return;
2319 } else if (cache->uc_allocbucket) {
2320 #ifdef UMA_DEBUG_ALLOC
2321 printf("uma_zfree: Swapping buckets.\n");
2322 #endif
2323 /*
2324 * We have run out of space in our freebucket.
2325 * See if we can switch with our alloc bucket.
2326 */
2327 if (cache->uc_allocbucket->ub_cnt <
2328 cache->uc_freebucket->ub_cnt) {
2329 bucket = cache->uc_freebucket;
2330 cache->uc_freebucket = cache->uc_allocbucket;
2331 cache->uc_allocbucket = bucket;
2332 goto zfree_start;
2333 }
2334 }
2335 }
2336 /*
2337 * We can get here for two reasons:
2338 *
2339 * 1) The buckets are NULL
2340 * 2) The alloc and free buckets are both somewhat full.
2341 *
2342 * We must go back the zone, which requires acquiring the zone lock,
2343 * which in turn means we must release and re-acquire the critical
2344 * section. Since the critical section is released, we may be
2345 * preempted or migrate. As such, make sure not to maintain any
2346 * thread-local state specific to the cache from prior to releasing
2347 * the critical section.
2348 */
2349 critical_exit();
2350 ZONE_LOCK(zone);
2351 critical_enter();
2352 cpu = curcpu;
2353 cache = &zone->uz_cpu[cpu];
2354 if (cache->uc_freebucket != NULL) {
2355 if (cache->uc_freebucket->ub_cnt <
2356 cache->uc_freebucket->ub_entries) {
2357 ZONE_UNLOCK(zone);
2358 goto zfree_start;
2359 }
2360 if (cache->uc_allocbucket != NULL &&
2361 (cache->uc_allocbucket->ub_cnt <
2362 cache->uc_freebucket->ub_cnt)) {
2363 ZONE_UNLOCK(zone);
2364 goto zfree_start;
2365 }
2366 }
2367
2368 /* Since we have locked the zone we may as well send back our stats */
2369 zone->uz_allocs += cache->uc_allocs;
2370 cache->uc_allocs = 0;
2371 zone->uz_frees += cache->uc_frees;
2372 cache->uc_frees = 0;
2373
2374 bucket = cache->uc_freebucket;
2375 cache->uc_freebucket = NULL;
2376
2377 /* Can we throw this on the zone full list? */
2378 if (bucket != NULL) {
2379 #ifdef UMA_DEBUG_ALLOC
2380 printf("uma_zfree: Putting old bucket on the free list.\n");
2381 #endif
2382 /* ub_cnt is pointing to the last free item */
2383 KASSERT(bucket->ub_cnt != 0,
2384 ("uma_zfree: Attempting to insert an empty bucket onto the full list.\n"));
2385 LIST_INSERT_HEAD(&zone->uz_full_bucket,
2386 bucket, ub_link);
2387 }
2388 if ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) {
2389 LIST_REMOVE(bucket, ub_link);
2390 ZONE_UNLOCK(zone);
2391 cache->uc_freebucket = bucket;
2392 goto zfree_start;
2393 }
2394 /* We are no longer associated with this CPU. */
2395 critical_exit();
2396
2397 /* And the zone.. */
2398 ZONE_UNLOCK(zone);
2399
2400 #ifdef UMA_DEBUG_ALLOC
2401 printf("uma_zfree: Allocating new free bucket.\n");
2402 #endif
2403 bflags = M_NOWAIT;
2404
2405 if (keg->uk_flags & UMA_ZFLAG_CACHEONLY)
2406 bflags |= M_NOVM;
2407 bucket = bucket_alloc(zone->uz_count, bflags);
2408 if (bucket) {
2409 ZONE_LOCK(zone);
2410 LIST_INSERT_HEAD(&zone->uz_free_bucket,
2411 bucket, ub_link);
2412 ZONE_UNLOCK(zone);
2413 goto zfree_restart;
2414 }
2415
2416 /*
2417 * If nothing else caught this, we'll just do an internal free.
2418 */
2419 zfree_internal:
2420 uma_zfree_internal(zone, item, udata, SKIP_DTOR, ZFREE_STATFREE);
2421
2422 return;
2423 }
2424
2425 /*
2426 * Frees an item to an INTERNAL zone or allocates a free bucket
2427 *
2428 * Arguments:
2429 * zone The zone to free to
2430 * item The item we're freeing
2431 * udata User supplied data for the dtor
2432 * skip Skip dtors and finis
2433 */
2434 static void
2435 uma_zfree_internal(uma_zone_t zone, void *item, void *udata,
2436 enum zfreeskip skip, int flags)
2437 {
2438 uma_slab_t slab;
2439 uma_slabrefcnt_t slabref;
2440 uma_keg_t keg;
2441 u_int8_t *mem;
2442 u_int8_t freei;
2443
2444 keg = zone->uz_keg;
2445
2446 if (skip < SKIP_DTOR && zone->uz_dtor)
2447 zone->uz_dtor(item, keg->uk_size, udata);
2448 if (skip < SKIP_FINI && zone->uz_fini)
2449 zone->uz_fini(item, keg->uk_size);
2450
2451 ZONE_LOCK(zone);
2452
2453 if (flags & ZFREE_STATFAIL)
2454 zone->uz_fails++;
2455 if (flags & ZFREE_STATFREE)
2456 zone->uz_frees++;
2457
2458 if (!(keg->uk_flags & UMA_ZONE_MALLOC)) {
2459 mem = (u_int8_t *)((unsigned long)item & (~UMA_SLAB_MASK));
2460 if (keg->uk_flags & UMA_ZONE_HASH)
2461 slab = hash_sfind(&keg->uk_hash, mem);
2462 else {
2463 mem += keg->uk_pgoff;
2464 slab = (uma_slab_t)mem;
2465 }
2466 } else {
2467 slab = (uma_slab_t)udata;
2468 }
2469
2470 /* Do we need to remove from any lists? */
2471 if (slab->us_freecount+1 == keg->uk_ipers) {
2472 LIST_REMOVE(slab, us_link);
2473 LIST_INSERT_HEAD(&keg->uk_free_slab, slab, us_link);
2474 } else if (slab->us_freecount == 0) {
2475 LIST_REMOVE(slab, us_link);
2476 LIST_INSERT_HEAD(&keg->uk_part_slab, slab, us_link);
2477 }
2478
2479 /* Slab management stuff */
2480 freei = ((unsigned long)item - (unsigned long)slab->us_data)
2481 / keg->uk_rsize;
2482
2483 #ifdef INVARIANTS
2484 if (!skip)
2485 uma_dbg_free(zone, slab, item);
2486 #endif
2487
2488 if (keg->uk_flags & UMA_ZONE_REFCNT) {
2489 slabref = (uma_slabrefcnt_t)slab;
2490 slabref->us_freelist[freei].us_item = slab->us_firstfree;
2491 } else {
2492 slab->us_freelist[freei].us_item = slab->us_firstfree;
2493 }
2494 slab->us_firstfree = freei;
2495 slab->us_freecount++;
2496
2497 /* Zone statistics */
2498 keg->uk_free++;
2499
2500 if (keg->uk_flags & UMA_ZFLAG_FULL) {
2501 if (keg->uk_pages < keg->uk_maxpages)
2502 keg->uk_flags &= ~UMA_ZFLAG_FULL;
2503
2504 /* We can handle one more allocation */
2505 wakeup_one(keg);
2506 }
2507
2508 ZONE_UNLOCK(zone);
2509 }
2510
2511 /* See uma.h */
2512 void
2513 uma_zone_set_max(uma_zone_t zone, int nitems)
2514 {
2515 uma_keg_t keg;
2516
2517 keg = zone->uz_keg;
2518 ZONE_LOCK(zone);
2519 if (keg->uk_ppera > 1)
2520 keg->uk_maxpages = nitems * keg->uk_ppera;
2521 else
2522 keg->uk_maxpages = nitems / keg->uk_ipers;
2523
2524 if (keg->uk_maxpages * keg->uk_ipers < nitems)
2525 keg->uk_maxpages++;
2526
2527 ZONE_UNLOCK(zone);
2528 }
2529
2530 /* See uma.h */
2531 void
2532 uma_zone_set_init(uma_zone_t zone, uma_init uminit)
2533 {
2534 ZONE_LOCK(zone);
2535 KASSERT(zone->uz_keg->uk_pages == 0,
2536 ("uma_zone_set_init on non-empty keg"));
2537 zone->uz_keg->uk_init = uminit;
2538 ZONE_UNLOCK(zone);
2539 }
2540
2541 /* See uma.h */
2542 void
2543 uma_zone_set_fini(uma_zone_t zone, uma_fini fini)
2544 {
2545 ZONE_LOCK(zone);
2546 KASSERT(zone->uz_keg->uk_pages == 0,
2547 ("uma_zone_set_fini on non-empty keg"));
2548 zone->uz_keg->uk_fini = fini;
2549 ZONE_UNLOCK(zone);
2550 }
2551
2552 /* See uma.h */
2553 void
2554 uma_zone_set_zinit(uma_zone_t zone, uma_init zinit)
2555 {
2556 ZONE_LOCK(zone);
2557 KASSERT(zone->uz_keg->uk_pages == 0,
2558 ("uma_zone_set_zinit on non-empty keg"));
2559 zone->uz_init = zinit;
2560 ZONE_UNLOCK(zone);
2561 }
2562
2563 /* See uma.h */
2564 void
2565 uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini)
2566 {
2567 ZONE_LOCK(zone);
2568 KASSERT(zone->uz_keg->uk_pages == 0,
2569 ("uma_zone_set_zfini on non-empty keg"));
2570 zone->uz_fini = zfini;
2571 ZONE_UNLOCK(zone);
2572 }
2573
2574 /* See uma.h */
2575 /* XXX uk_freef is not actually used with the zone locked */
2576 void
2577 uma_zone_set_freef(uma_zone_t zone, uma_free freef)
2578 {
2579 ZONE_LOCK(zone);
2580 zone->uz_keg->uk_freef = freef;
2581 ZONE_UNLOCK(zone);
2582 }
2583
2584 /* See uma.h */
2585 /* XXX uk_allocf is not actually used with the zone locked */
2586 void
2587 uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf)
2588 {
2589 ZONE_LOCK(zone);
2590 zone->uz_keg->uk_flags |= UMA_ZFLAG_PRIVALLOC;
2591 zone->uz_keg->uk_allocf = allocf;
2592 ZONE_UNLOCK(zone);
2593 }
2594
2595 /* See uma.h */
2596 int
2597 uma_zone_set_obj(uma_zone_t zone, struct vm_object *obj, int count)
2598 {
2599 uma_keg_t keg;
2600 vm_offset_t kva;
2601 int pages;
2602
2603 keg = zone->uz_keg;
2604 pages = count / keg->uk_ipers;
2605
2606 if (pages * keg->uk_ipers < count)
2607 pages++;
2608
2609 kva = kmem_alloc_nofault(kernel_map, pages * UMA_SLAB_SIZE);
2610
2611 if (kva == 0)
2612 return (0);
2613 if (obj == NULL) {
2614 obj = vm_object_allocate(OBJT_DEFAULT,
2615 pages);
2616 } else {
2617 VM_OBJECT_LOCK_INIT(obj, "uma object");
2618 _vm_object_allocate(OBJT_DEFAULT,
2619 pages, obj);
2620 }
2621 ZONE_LOCK(zone);
2622 keg->uk_kva = kva;
2623 keg->uk_obj = obj;
2624 keg->uk_maxpages = pages;
2625 keg->uk_allocf = obj_alloc;
2626 keg->uk_flags |= UMA_ZONE_NOFREE | UMA_ZFLAG_PRIVALLOC;
2627 ZONE_UNLOCK(zone);
2628 return (1);
2629 }
2630
2631 /* See uma.h */
2632 void
2633 uma_prealloc(uma_zone_t zone, int items)
2634 {
2635 int slabs;
2636 uma_slab_t slab;
2637 uma_keg_t keg;
2638
2639 keg = zone->uz_keg;
2640 ZONE_LOCK(zone);
2641 slabs = items / keg->uk_ipers;
2642 if (slabs * keg->uk_ipers < items)
2643 slabs++;
2644 while (slabs > 0) {
2645 slab = slab_zalloc(zone, M_WAITOK);
2646 LIST_INSERT_HEAD(&keg->uk_free_slab, slab, us_link);
2647 slabs--;
2648 }
2649 ZONE_UNLOCK(zone);
2650 }
2651
2652 /* See uma.h */
2653 u_int32_t *
2654 uma_find_refcnt(uma_zone_t zone, void *item)
2655 {
2656 uma_slabrefcnt_t slabref;
2657 uma_keg_t keg;
2658 u_int32_t *refcnt;
2659 int idx;
2660
2661 keg = zone->uz_keg;
2662 slabref = (uma_slabrefcnt_t)vtoslab((vm_offset_t)item &
2663 (~UMA_SLAB_MASK));
2664 KASSERT(slabref != NULL && slabref->us_keg->uk_flags & UMA_ZONE_REFCNT,
2665 ("uma_find_refcnt(): zone possibly not UMA_ZONE_REFCNT"));
2666 idx = ((unsigned long)item - (unsigned long)slabref->us_data)
2667 / keg->uk_rsize;
2668 refcnt = &slabref->us_freelist[idx].us_refcnt;
2669 return refcnt;
2670 }
2671
2672 /* See uma.h */
2673 void
2674 uma_reclaim(void)
2675 {
2676 #ifdef UMA_DEBUG
2677 printf("UMA: vm asked us to release pages!\n");
2678 #endif
2679 bucket_enable();
2680 zone_foreach(zone_drain);
2681 /*
2682 * Some slabs may have been freed but this zone will be visited early
2683 * we visit again so that we can free pages that are empty once other
2684 * zones are drained. We have to do the same for buckets.
2685 */
2686 zone_drain(slabzone);
2687 zone_drain(slabrefzone);
2688 bucket_zone_drain();
2689 }
2690
2691 void *
2692 uma_large_malloc(int size, int wait)
2693 {
2694 void *mem;
2695 uma_slab_t slab;
2696 u_int8_t flags;
2697
2698 slab = uma_zalloc_internal(slabzone, NULL, wait);
2699 if (slab == NULL)
2700 return (NULL);
2701 mem = page_alloc(NULL, size, &flags, wait);
2702 if (mem) {
2703 vsetslab((vm_offset_t)mem, slab);
2704 slab->us_data = mem;
2705 slab->us_flags = flags | UMA_SLAB_MALLOC;
2706 slab->us_size = size;
2707 } else {
2708 uma_zfree_internal(slabzone, slab, NULL, SKIP_NONE,
2709 ZFREE_STATFAIL | ZFREE_STATFREE);
2710 }
2711
2712 return (mem);
2713 }
2714
2715 void
2716 uma_large_free(uma_slab_t slab)
2717 {
2718 vsetobj((vm_offset_t)slab->us_data, kmem_object);
2719 page_free(slab->us_data, slab->us_size, slab->us_flags);
2720 uma_zfree_internal(slabzone, slab, NULL, SKIP_NONE, ZFREE_STATFREE);
2721 }
2722
2723 void
2724 uma_print_stats(void)
2725 {
2726 zone_foreach(uma_print_zone);
2727 }
2728
2729 static void
2730 slab_print(uma_slab_t slab)
2731 {
2732 printf("slab: keg %p, data %p, freecount %d, firstfree %d\n",
2733 slab->us_keg, slab->us_data, slab->us_freecount,
2734 slab->us_firstfree);
2735 }
2736
2737 static void
2738 cache_print(uma_cache_t cache)
2739 {
2740 printf("alloc: %p(%d), free: %p(%d)\n",
2741 cache->uc_allocbucket,
2742 cache->uc_allocbucket?cache->uc_allocbucket->ub_cnt:0,
2743 cache->uc_freebucket,
2744 cache->uc_freebucket?cache->uc_freebucket->ub_cnt:0);
2745 }
2746
2747 void
2748 uma_print_zone(uma_zone_t zone)
2749 {
2750 uma_cache_t cache;
2751 uma_keg_t keg;
2752 uma_slab_t slab;
2753 int i;
2754
2755 keg = zone->uz_keg;
2756 printf("%s(%p) size %d(%d) flags %d ipers %d ppera %d out %d free %d\n",
2757 zone->uz_name, zone, keg->uk_size, keg->uk_rsize, keg->uk_flags,
2758 keg->uk_ipers, keg->uk_ppera,
2759 (keg->uk_ipers * keg->uk_pages) - keg->uk_free, keg->uk_free);
2760 printf("Part slabs:\n");
2761 LIST_FOREACH(slab, &keg->uk_part_slab, us_link)
2762 slab_print(slab);
2763 printf("Free slabs:\n");
2764 LIST_FOREACH(slab, &keg->uk_free_slab, us_link)
2765 slab_print(slab);
2766 printf("Full slabs:\n");
2767 LIST_FOREACH(slab, &keg->uk_full_slab, us_link)
2768 slab_print(slab);
2769 for (i = 0; i <= mp_maxid; i++) {
2770 if (CPU_ABSENT(i))
2771 continue;
2772 cache = &zone->uz_cpu[i];
2773 printf("CPU %d Cache:\n", i);
2774 cache_print(cache);
2775 }
2776 }
2777
2778 /*
2779 * Generate statistics across both the zone and its per-cpu cache's. Return
2780 * desired statistics if the pointer is non-NULL for that statistic.
2781 *
2782 * Note: does not update the zone statistics, as it can't safely clear the
2783 * per-CPU cache statistic.
2784 *
2785 * XXXRW: Following the uc_allocbucket and uc_freebucket pointers here isn't
2786 * safe from off-CPU; we should modify the caches to track this information
2787 * directly so that we don't have to.
2788 */
2789 static void
2790 uma_zone_sumstat(uma_zone_t z, int *cachefreep, u_int64_t *allocsp,
2791 u_int64_t *freesp)
2792 {
2793 uma_cache_t cache;
2794 u_int64_t allocs, frees;
2795 int cachefree, cpu;
2796
2797 allocs = frees = 0;
2798 cachefree = 0;
2799 for (cpu = 0; cpu <= mp_maxid; cpu++) {
2800 if (CPU_ABSENT(cpu))
2801 continue;
2802 cache = &z->uz_cpu[cpu];
2803 if (cache->uc_allocbucket != NULL)
2804 cachefree += cache->uc_allocbucket->ub_cnt;
2805 if (cache->uc_freebucket != NULL)
2806 cachefree += cache->uc_freebucket->ub_cnt;
2807 allocs += cache->uc_allocs;
2808 frees += cache->uc_frees;
2809 }
2810 allocs += z->uz_allocs;
2811 frees += z->uz_frees;
2812 if (cachefreep != NULL)
2813 *cachefreep = cachefree;
2814 if (allocsp != NULL)
2815 *allocsp = allocs;
2816 if (freesp != NULL)
2817 *freesp = frees;
2818 }
2819
2820 /*
2821 * Sysctl handler for vm.zone
2822 *
2823 * stolen from vm_zone.c
2824 */
2825 static int
2826 sysctl_vm_zone(SYSCTL_HANDLER_ARGS)
2827 {
2828 int error, len, cnt;
2829 const int linesize = 128; /* conservative */
2830 int totalfree;
2831 char *tmpbuf, *offset;
2832 uma_zone_t z;
2833 uma_keg_t zk;
2834 char *p;
2835 int cachefree;
2836 uma_bucket_t bucket;
2837 u_int64_t allocs, frees;
2838
2839 cnt = 0;
2840 mtx_lock(&uma_mtx);
2841 LIST_FOREACH(zk, &uma_kegs, uk_link) {
2842 LIST_FOREACH(z, &zk->uk_zones, uz_link)
2843 cnt++;
2844 }
2845 mtx_unlock(&uma_mtx);
2846 MALLOC(tmpbuf, char *, (cnt == 0 ? 1 : cnt) * linesize,
2847 M_TEMP, M_WAITOK);
2848 len = snprintf(tmpbuf, linesize,
2849 "\nITEM SIZE LIMIT USED FREE REQUESTS\n\n");
2850 if (cnt == 0)
2851 tmpbuf[len - 1] = '\0';
2852 error = SYSCTL_OUT(req, tmpbuf, cnt == 0 ? len-1 : len);
2853 if (error || cnt == 0)
2854 goto out;
2855 offset = tmpbuf;
2856 mtx_lock(&uma_mtx);
2857 LIST_FOREACH(zk, &uma_kegs, uk_link) {
2858 LIST_FOREACH(z, &zk->uk_zones, uz_link) {
2859 if (cnt == 0) /* list may have changed size */
2860 break;
2861 ZONE_LOCK(z);
2862 cachefree = 0;
2863 if (!(zk->uk_flags & UMA_ZFLAG_INTERNAL)) {
2864 uma_zone_sumstat(z, &cachefree, &allocs, &frees);
2865 } else {
2866 allocs = z->uz_allocs;
2867 frees = z->uz_frees;
2868 }
2869
2870 LIST_FOREACH(bucket, &z->uz_full_bucket, ub_link) {
2871 cachefree += bucket->ub_cnt;
2872 }
2873 totalfree = zk->uk_free + cachefree;
2874 len = snprintf(offset, linesize,
2875 "%-12.12s %6.6u, %8.8u, %6.6u, %6.6u, %8.8llu\n",
2876 z->uz_name, zk->uk_size,
2877 zk->uk_maxpages * zk->uk_ipers,
2878 (zk->uk_ipers * (zk->uk_pages / zk->uk_ppera)) - totalfree,
2879 totalfree,
2880 (unsigned long long)allocs);
2881 ZONE_UNLOCK(z);
2882 for (p = offset + 12; p > offset && *p == ' '; --p)
2883 /* nothing */ ;
2884 p[1] = ':';
2885 cnt--;
2886 offset += len;
2887 }
2888 }
2889 mtx_unlock(&uma_mtx);
2890 *offset++ = '\0';
2891 error = SYSCTL_OUT(req, tmpbuf, offset - tmpbuf);
2892 out:
2893 FREE(tmpbuf, M_TEMP);
2894 return (error);
2895 }
2896
2897 static int
2898 sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS)
2899 {
2900 uma_keg_t kz;
2901 uma_zone_t z;
2902 int count;
2903
2904 count = 0;
2905 mtx_lock(&uma_mtx);
2906 LIST_FOREACH(kz, &uma_kegs, uk_link) {
2907 LIST_FOREACH(z, &kz->uk_zones, uz_link)
2908 count++;
2909 }
2910 mtx_unlock(&uma_mtx);
2911 return (sysctl_handle_int(oidp, &count, 0, req));
2912 }
2913
2914 static int
2915 sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS)
2916 {
2917 struct uma_stream_header ush;
2918 struct uma_type_header uth;
2919 struct uma_percpu_stat ups;
2920 uma_bucket_t bucket;
2921 struct sbuf sbuf;
2922 uma_cache_t cache;
2923 uma_keg_t kz;
2924 uma_zone_t z;
2925 char *buffer;
2926 int buflen, count, error, i;
2927
2928 mtx_lock(&uma_mtx);
2929 restart:
2930 mtx_assert(&uma_mtx, MA_OWNED);
2931 count = 0;
2932 LIST_FOREACH(kz, &uma_kegs, uk_link) {
2933 LIST_FOREACH(z, &kz->uk_zones, uz_link)
2934 count++;
2935 }
2936 mtx_unlock(&uma_mtx);
2937
2938 buflen = sizeof(ush) + count * (sizeof(uth) + sizeof(ups) *
2939 (mp_maxid + 1)) + 1;
2940 buffer = malloc(buflen, M_TEMP, M_WAITOK | M_ZERO);
2941
2942 mtx_lock(&uma_mtx);
2943 i = 0;
2944 LIST_FOREACH(kz, &uma_kegs, uk_link) {
2945 LIST_FOREACH(z, &kz->uk_zones, uz_link)
2946 i++;
2947 }
2948 if (i > count) {
2949 free(buffer, M_TEMP);
2950 goto restart;
2951 }
2952 count = i;
2953
2954 sbuf_new(&sbuf, buffer, buflen, SBUF_FIXEDLEN);
2955
2956 /*
2957 * Insert stream header.
2958 */
2959 bzero(&ush, sizeof(ush));
2960 ush.ush_version = UMA_STREAM_VERSION;
2961 ush.ush_maxcpus = (mp_maxid + 1);
2962 ush.ush_count = count;
2963 if (sbuf_bcat(&sbuf, &ush, sizeof(ush)) < 0) {
2964 mtx_unlock(&uma_mtx);
2965 error = ENOMEM;
2966 goto out;
2967 }
2968
2969 LIST_FOREACH(kz, &uma_kegs, uk_link) {
2970 LIST_FOREACH(z, &kz->uk_zones, uz_link) {
2971 bzero(&uth, sizeof(uth));
2972 ZONE_LOCK(z);
2973 strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
2974 uth.uth_align = kz->uk_align;
2975 uth.uth_pages = kz->uk_pages;
2976 uth.uth_keg_free = kz->uk_free;
2977 uth.uth_size = kz->uk_size;
2978 uth.uth_rsize = kz->uk_rsize;
2979 uth.uth_maxpages = kz->uk_maxpages;
2980 if (kz->uk_ppera > 1)
2981 uth.uth_limit = kz->uk_maxpages /
2982 kz->uk_ppera;
2983 else
2984 uth.uth_limit = kz->uk_maxpages *
2985 kz->uk_ipers;
2986
2987 /*
2988 * A zone is secondary is it is not the first entry
2989 * on the keg's zone list.
2990 */
2991 if ((kz->uk_flags & UMA_ZONE_SECONDARY) &&
2992 (LIST_FIRST(&kz->uk_zones) != z))
2993 uth.uth_zone_flags = UTH_ZONE_SECONDARY;
2994
2995 LIST_FOREACH(bucket, &z->uz_full_bucket, ub_link)
2996 uth.uth_zone_free += bucket->ub_cnt;
2997 uth.uth_allocs = z->uz_allocs;
2998 uth.uth_frees = z->uz_frees;
2999 uth.uth_fails = z->uz_fails;
3000 if (sbuf_bcat(&sbuf, &uth, sizeof(uth)) < 0) {
3001 ZONE_UNLOCK(z);
3002 mtx_unlock(&uma_mtx);
3003 error = ENOMEM;
3004 goto out;
3005 }
3006 /*
3007 * While it is not normally safe to access the cache
3008 * bucket pointers while not on the CPU that owns the
3009 * cache, we only allow the pointers to be exchanged
3010 * without the zone lock held, not invalidated, so
3011 * accept the possible race associated with bucket
3012 * exchange during monitoring.
3013 */
3014 for (i = 0; i < (mp_maxid + 1); i++) {
3015 bzero(&ups, sizeof(ups));
3016 if (kz->uk_flags & UMA_ZFLAG_INTERNAL)
3017 goto skip;
3018 if (CPU_ABSENT(i))
3019 goto skip;
3020 cache = &z->uz_cpu[i];
3021 if (cache->uc_allocbucket != NULL)
3022 ups.ups_cache_free +=
3023 cache->uc_allocbucket->ub_cnt;
3024 if (cache->uc_freebucket != NULL)
3025 ups.ups_cache_free +=
3026 cache->uc_freebucket->ub_cnt;
3027 ups.ups_allocs = cache->uc_allocs;
3028 ups.ups_frees = cache->uc_frees;
3029 skip:
3030 if (sbuf_bcat(&sbuf, &ups, sizeof(ups)) < 0) {
3031 ZONE_UNLOCK(z);
3032 mtx_unlock(&uma_mtx);
3033 error = ENOMEM;
3034 goto out;
3035 }
3036 }
3037 ZONE_UNLOCK(z);
3038 }
3039 }
3040 mtx_unlock(&uma_mtx);
3041 sbuf_finish(&sbuf);
3042 error = SYSCTL_OUT(req, sbuf_data(&sbuf), sbuf_len(&sbuf));
3043 out:
3044 free(buffer, M_TEMP);
3045 return (error);
3046 }
3047
3048 #ifdef DDB
3049 DB_SHOW_COMMAND(uma, db_show_uma)
3050 {
3051 u_int64_t allocs, frees;
3052 uma_bucket_t bucket;
3053 uma_keg_t kz;
3054 uma_zone_t z;
3055 int cachefree;
3056
3057 db_printf("%18s %12s %12s %12s %8s\n", "Zone", "Allocs", "Frees",
3058 "Used", "Cache");
3059 LIST_FOREACH(kz, &uma_kegs, uk_link) {
3060 LIST_FOREACH(z, &kz->uk_zones, uz_link) {
3061 if (kz->uk_flags & UMA_ZFLAG_INTERNAL) {
3062 allocs = z->uz_allocs;
3063 frees = z->uz_frees;
3064 cachefree = 0;
3065 } else
3066 uma_zone_sumstat(z, &cachefree, &allocs,
3067 &frees);
3068 if (!((kz->uk_flags & UMA_ZONE_SECONDARY) &&
3069 (LIST_FIRST(&kz->uk_zones) != z)))
3070 cachefree += kz->uk_free;
3071 LIST_FOREACH(bucket, &z->uz_full_bucket, ub_link)
3072 cachefree += bucket->ub_cnt;
3073 db_printf("%18s %12ju %12ju %12ju %8d\n", z->uz_name,
3074 allocs, frees, allocs - frees, cachefree);
3075 }
3076 }
3077 }
3078 #endif
Cache object: 7e09fbf2890d4170f73d23700d630692
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