1/*
2 * Copyright (c) 2002, Jeffrey Roberson <jroberson@chesapeake.net>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice unmodified, this list of conditions, and the following
10 * disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 *
|
26 * $FreeBSD: head/sys/vm/uma_core.c 94159 2002-04-08 02:42:55Z jeff $
|
| 26 * $FreeBSD: head/sys/vm/uma_core.c 94161 2002-04-08 04:48:58Z jeff $ |
27 *
28 */
29
30/*
31 * uma_core.c Implementation of the Universal Memory allocator
32 *
33 * This allocator is intended to replace the multitude of similar object caches
34 * in the standard FreeBSD kernel. The intent is to be flexible as well as
35 * effecient. A primary design goal is to return unused memory to the rest of
36 * the system. This will make the system as a whole more flexible due to the
37 * ability to move memory to subsystems which most need it instead of leaving
38 * pools of reserved memory unused.
39 *
40 * The basic ideas stem from similar slab/zone based allocators whose algorithms
41 * are well known.
42 *
43 */
44
45/*
46 * TODO:
47 * - Improve memory usage for large allocations
48 * - Improve INVARIANTS (0xdeadc0de write out)
49 * - Investigate cache size adjustments
50 */
51
52/* I should really use ktr.. */
53/*
54#define UMA_DEBUG 1
55#define UMA_DEBUG_ALLOC 1
56#define UMA_DEBUG_ALLOC_1 1
57*/
58
59
60#include "opt_param.h"
61#include <sys/param.h>
62#include <sys/systm.h>
63#include <sys/kernel.h>
64#include <sys/types.h>
65#include <sys/queue.h>
66#include <sys/malloc.h>
67#include <sys/lock.h>
68#include <sys/sysctl.h>
69#include <machine/types.h>
70#include <sys/mutex.h>
71#include <sys/smp.h>
72
73#include <vm/vm.h>
74#include <vm/vm_object.h>
75#include <vm/vm_page.h>
76#include <vm/vm_param.h>
77#include <vm/vm_map.h>
78#include <vm/vm_kern.h>
79#include <vm/vm_extern.h>
80#include <vm/uma.h>
81#include <vm/uma_int.h>
82
83/*
84 * This is the zone from which all zones are spawned. The idea is that even
85 * the zone heads are allocated from the allocator, so we use the bss section
86 * to bootstrap us.
87 */
88static struct uma_zone master_zone;
89static uma_zone_t zones = &master_zone;
90
91/* This is the zone from which all of uma_slab_t's are allocated. */
92static uma_zone_t slabzone;
93
94/*
95 * The initial hash tables come out of this zone so they can be allocated
96 * prior to malloc coming up.
97 */
98static uma_zone_t hashzone;
99
100/*
101 * Zone that buckets come from.
102 */
103static uma_zone_t bucketzone;
104
105/* Linked list of all zones in the system */
106static LIST_HEAD(,uma_zone) uma_zones = LIST_HEAD_INITIALIZER(&uma_zones);
107
108/* This mutex protects the zone list */
109static struct mtx uma_mtx;
110
111/* Linked list of boot time pages */
112static LIST_HEAD(,uma_slab) uma_boot_pages =
113 LIST_HEAD_INITIALIZER(&uma_boot_pages);
114
115/* Count of free boottime pages */
116static int uma_boot_free = 0;
117
118/* Is the VM done starting up? */
119static int booted = 0;
120
121/* This is the handle used to schedule our working set calculator */
122static struct callout uma_callout;
123
124/* This is mp_maxid + 1, for use while looping over each cpu */
125static int maxcpu;
126
127/*
128 * This structure is passed as the zone ctor arg so that I don't have to create
129 * a special allocation function just for zones.
130 */
131struct uma_zctor_args {
132 char *name;
133 int size;
134 uma_ctor ctor;
135 uma_dtor dtor;
136 uma_init uminit;
137 uma_fini fini;
138 int align;
139 u_int16_t flags;
140};
141
142/*
143 * This is the malloc hash table which is used to find the zone that a
144 * malloc allocation came from. It is not currently resizeable. The
145 * memory for the actual hash bucket is allocated in kmeminit.
146 */
147struct uma_hash mhash;
148struct uma_hash *mallochash = &mhash;
149
150/* Prototypes.. */
151
152static void *obj_alloc(uma_zone_t, int, u_int8_t *, int);
153static void *page_alloc(uma_zone_t, int, u_int8_t *, int);
154static void page_free(void *, int, u_int8_t);
155static uma_slab_t slab_zalloc(uma_zone_t, int);
156static void cache_drain(uma_zone_t);
157static void bucket_drain(uma_zone_t, uma_bucket_t);
158static void zone_drain(uma_zone_t);
159static void zone_ctor(void *, int, void *);
|
| 160static void zone_dtor(void *, int, void *); |
161static void zero_init(void *, int);
162static void zone_small_init(uma_zone_t zone);
163static void zone_large_init(uma_zone_t zone);
164static void zone_foreach(void (*zfunc)(uma_zone_t));
165static void zone_timeout(uma_zone_t zone);
166static void hash_expand(struct uma_hash *);
|
| 167static void hash_free(struct uma_hash *hash); |
168static void uma_timeout(void *);
169static void uma_startup3(void);
170static void *uma_zalloc_internal(uma_zone_t, void *, int, uma_bucket_t);
171static void uma_zfree_internal(uma_zone_t,
172 void *, void *, int);
173void uma_print_zone(uma_zone_t);
174void uma_print_stats(void);
175static int sysctl_vm_zone(SYSCTL_HANDLER_ARGS);
176
177SYSCTL_OID(_vm, OID_AUTO, zone, CTLTYPE_STRING|CTLFLAG_RD,
178 NULL, 0, sysctl_vm_zone, "A", "Zone Info");
179SYSINIT(uma_startup3, SI_SUB_VM_CONF, SI_ORDER_SECOND, uma_startup3, NULL);
180
181
182/*
183 * Routine called by timeout which is used to fire off some time interval
184 * based calculations. (working set, stats, etc.)
185 *
186 * Arguments:
187 * arg Unused
188 *
189 * Returns:
190 * Nothing
191 */
192static void
193uma_timeout(void *unused)
194{
195 zone_foreach(zone_timeout);
196
197 /* Reschedule this event */
198 callout_reset(&uma_callout, UMA_WORKING_TIME * hz, uma_timeout, NULL);
199}
200
201/*
202 * Routine to perform timeout driven calculations. This does the working set
203 * as well as hash expanding, and per cpu statistics aggregation.
204 *
205 * Arguments:
206 * zone The zone to operate on
207 *
208 * Returns:
209 * Nothing
210 */
211static void
212zone_timeout(uma_zone_t zone)
213{
214 uma_cache_t cache;
215 u_int64_t alloc;
216 int free;
217 int cpu;
218
219 alloc = 0;
220 free = 0;
221
222 /*
223 * Aggregate per cpu cache statistics back to the zone.
224 *
225 * I may rewrite this to set a flag in the per cpu cache instead of
226 * locking. If the flag is not cleared on the next round I will have
227 * to lock and do it here instead so that the statistics don't get too
228 * far out of sync.
229 */
230 if (!(zone->uz_flags & UMA_ZFLAG_INTERNAL)) {
231 for (cpu = 0; cpu < maxcpu; cpu++) {
232 if (CPU_ABSENT(cpu))
233 continue;
234 CPU_LOCK(zone, cpu);
235 cache = &zone->uz_cpu[cpu];
236 /* Add them up, and reset */
237 alloc += cache->uc_allocs;
238 cache->uc_allocs = 0;
239 if (cache->uc_allocbucket)
240 free += cache->uc_allocbucket->ub_ptr + 1;
241 if (cache->uc_freebucket)
242 free += cache->uc_freebucket->ub_ptr + 1;
243 CPU_UNLOCK(zone, cpu);
244 }
245 }
246
247 /* Now push these stats back into the zone.. */
248 ZONE_LOCK(zone);
249 zone->uz_allocs += alloc;
250
251 /*
252 * cachefree is an instantanious snapshot of what is in the per cpu
253 * caches, not an accurate counter
254 */
255 zone->uz_cachefree = free;
256
257 /*
258 * Expand the zone hash table.
259 *
260 * This is done if the number of slabs is larger than the hash size.
261 * What I'm trying to do here is completely reduce collisions. This
262 * may be a little aggressive. Should I allow for two collisions max?
263 */
264
265 if ((zone->uz_flags & UMA_ZFLAG_OFFPAGE) &&
266 !(zone->uz_flags & UMA_ZFLAG_MALLOC)) {
267 if (zone->uz_pages / zone->uz_ppera
268 >= zone->uz_hash.uh_hashsize)
269 hash_expand(&zone->uz_hash);
270 }
271
272 /*
273 * Here we compute the working set size as the total number of items
274 * left outstanding since the last time interval. This is slightly
275 * suboptimal. What we really want is the highest number of outstanding
276 * items during the last time quantum. This should be close enough.
277 *
278 * The working set size is used to throttle the zone_drain function.
279 * We don't want to return memory that we may need again immediately.
280 */
281 alloc = zone->uz_allocs - zone->uz_oallocs;
282 zone->uz_oallocs = zone->uz_allocs;
283 zone->uz_wssize = alloc;
284
285 ZONE_UNLOCK(zone);
286}
287
288/*
289 * Expands the hash table for OFFPAGE zones. This is done from zone_timeout
290 * to reduce collisions. This must not be done in the regular allocation path,
291 * otherwise, we can recurse on the vm while allocating pages.
292 *
293 * Arguments:
294 * hash The hash you want to expand by a factor of two.
295 *
296 * Returns:
297 * Nothing
298 *
299 * Discussion:
300 */
301static void
302hash_expand(struct uma_hash *hash)
303{
304 struct slabhead *newhash;
305 struct slabhead *oldhash;
306 uma_slab_t slab;
|
305 int hzonefree;
306 int hashsize;
|
307 int oldsize;
308 int newsize; |
309 int alloc;
310 int hval;
311 int i;
312
313
314 /*
315 * Remember the old hash size and see if it has to go back to the
316 * hash zone, or malloc. The hash zone is used for the initial hash
317 */
318
|
317 hashsize = hash->uh_hashsize;
|
| 319 oldsize = hash->uh_hashsize; |
320 oldhash = hash->uh_slab_hash;
321
|
320 if (hashsize == UMA_HASH_SIZE_INIT)
321 hzonefree = 1;
322 else
323 hzonefree = 0;
324
325
|
322 /* We're just going to go to a power of two greater */
323 if (hash->uh_hashsize) {
|
328 alloc = sizeof(hash->uh_slab_hash[0]) * (hash->uh_hashsize * 2);
|
324 newsize = oldsize * 2;
325 alloc = sizeof(hash->uh_slab_hash[0]) * newsize; |
326 /* XXX Shouldn't be abusing DEVBUF here */
327 newhash = (struct slabhead *)malloc(alloc, M_DEVBUF, M_NOWAIT);
328 if (newhash == NULL) {
329 return;
330 }
|
334 hash->uh_hashsize *= 2;
|
331 } else {
332 alloc = sizeof(hash->uh_slab_hash[0]) * UMA_HASH_SIZE_INIT;
333 newhash = uma_zalloc_internal(hashzone, NULL, M_WAITOK, NULL);
|
338 hash->uh_hashsize = UMA_HASH_SIZE_INIT;
|
| 334 newsize = UMA_HASH_SIZE_INIT; |
335 }
336
337 bzero(newhash, alloc);
338
|
343 hash->uh_hashmask = hash->uh_hashsize - 1;
|
| 339 hash->uh_hashmask = newsize - 1; |
340
341 /*
342 * I need to investigate hash algorithms for resizing without a
343 * full rehash.
344 */
345
|
350 for (i = 0; i < hashsize; i++)
|
| 346 for (i = 0; i < oldsize; i++) |
347 while (!SLIST_EMPTY(&hash->uh_slab_hash[i])) {
348 slab = SLIST_FIRST(&hash->uh_slab_hash[i]);
349 SLIST_REMOVE_HEAD(&hash->uh_slab_hash[i], us_hlink);
350 hval = UMA_HASH(hash, slab->us_data);
351 SLIST_INSERT_HEAD(&newhash[hval], slab, us_hlink);
352 }
353
|
358 if (hash->uh_slab_hash) {
359 if (hzonefree)
360 uma_zfree_internal(hashzone,
361 hash->uh_slab_hash, NULL, 0);
362 else
363 free(hash->uh_slab_hash, M_DEVBUF);
364 }
|
354 if (oldhash)
355 hash_free(hash);
356 |
357 hash->uh_slab_hash = newhash;
|
| 358 hash->uh_hashsize = newsize; |
359
360 return;
361}
362
|
363static void
364hash_free(struct uma_hash *hash)
365{
366 if (hash->uh_hashsize == UMA_HASH_SIZE_INIT)
367 uma_zfree_internal(hashzone,
368 hash->uh_slab_hash, NULL, 0);
369 else
370 free(hash->uh_slab_hash, M_DEVBUF);
371
372 hash->uh_slab_hash = NULL;
373}
374 |
375/*
376 * Frees all outstanding items in a bucket
377 *
378 * Arguments:
379 * zone The zone to free to, must be unlocked.
380 * bucket The free/alloc bucket with items, cpu queue must be locked.
381 *
382 * Returns:
383 * Nothing
384 */
385
386static void
387bucket_drain(uma_zone_t zone, uma_bucket_t bucket)
388{
389 uma_slab_t slab;
390 int mzone;
391 void *item;
392
393 if (bucket == NULL)
394 return;
395
396 slab = NULL;
397 mzone = 0;
398
399 /* We have to lookup the slab again for malloc.. */
400 if (zone->uz_flags & UMA_ZFLAG_MALLOC)
401 mzone = 1;
402
403 while (bucket->ub_ptr > -1) {
404 item = bucket->ub_bucket[bucket->ub_ptr];
405#ifdef INVARIANTS
406 bucket->ub_bucket[bucket->ub_ptr] = NULL;
407 KASSERT(item != NULL,
408 ("bucket_drain: botched ptr, item is NULL"));
409#endif
410 bucket->ub_ptr--;
411 /*
412 * This is extremely inefficient. The slab pointer was passed
413 * to uma_zfree_arg, but we lost it because the buckets don't
414 * hold them. This will go away when free() gets a size passed
415 * to it.
416 */
417 if (mzone)
418 slab = hash_sfind(mallochash,
419 (u_int8_t *)((unsigned long)item &
420 (~UMA_SLAB_MASK)));
421 uma_zfree_internal(zone, item, slab, 1);
422 }
423}
424
425/*
426 * Drains the per cpu caches for a zone.
427 *
428 * Arguments:
429 * zone The zone to drain, must be unlocked.
430 *
431 * Returns:
432 * Nothing
433 *
434 * This function returns with the zone locked so that the per cpu queues can
435 * not be filled until zone_drain is finished.
436 *
437 */
438static void
439cache_drain(uma_zone_t zone)
440{
441 uma_bucket_t bucket;
442 uma_cache_t cache;
443 int cpu;
444
445 /*
446 * Flush out the per cpu queues.
447 *
448 * XXX This causes unnecessary thrashing due to immediately having
449 * empty per cpu queues. I need to improve this.
450 */
451
452 /*
453 * We have to lock each cpu cache before locking the zone
454 */
455 ZONE_UNLOCK(zone);
456
457 for (cpu = 0; cpu < maxcpu; cpu++) {
458 if (CPU_ABSENT(cpu))
459 continue;
460 CPU_LOCK(zone, cpu);
461 cache = &zone->uz_cpu[cpu];
462 bucket_drain(zone, cache->uc_allocbucket);
463 bucket_drain(zone, cache->uc_freebucket);
464 }
465
466 /*
467 * Drain the bucket queues and free the buckets, we just keep two per
468 * cpu (alloc/free).
469 */
470 ZONE_LOCK(zone);
471 while ((bucket = LIST_FIRST(&zone->uz_full_bucket)) != NULL) {
472 LIST_REMOVE(bucket, ub_link);
473 ZONE_UNLOCK(zone);
474 bucket_drain(zone, bucket);
475 uma_zfree_internal(bucketzone, bucket, NULL, 0);
476 ZONE_LOCK(zone);
477 }
478
479 /* Now we do the free queue.. */
480 while ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) {
481 LIST_REMOVE(bucket, ub_link);
482 uma_zfree_internal(bucketzone, bucket, NULL, 0);
483 }
484
485 /* We unlock here, but they will all block until the zone is unlocked */
486 for (cpu = 0; cpu < maxcpu; cpu++) {
487 if (CPU_ABSENT(cpu))
488 continue;
489 CPU_UNLOCK(zone, cpu);
490 }
491
492 zone->uz_cachefree = 0;
493}
494
495/*
496 * Frees pages from a zone back to the system. This is done on demand from
497 * the pageout daemon.
498 *
499 * Arguments:
500 * zone The zone to free pages from
|
| 501 * all Should we drain all items? |
502 *
503 * Returns:
504 * Nothing.
505 */
506static void
507zone_drain(uma_zone_t zone)
508{
509 uma_slab_t slab;
510 uma_slab_t n;
511 u_int64_t extra;
512 u_int8_t flags;
513 u_int8_t *mem;
514 int i;
515
516 /*
517 * We don't want to take pages from staticly allocated zones at this
518 * time
519 */
520 if (zone->uz_flags & UMA_ZFLAG_NOFREE || zone->uz_freef == NULL)
521 return;
522
523 ZONE_LOCK(zone);
524
525 if (!(zone->uz_flags & UMA_ZFLAG_INTERNAL))
526 cache_drain(zone);
527
528 if (zone->uz_free < zone->uz_wssize)
529 goto finished;
530#ifdef UMA_DEBUG
531 printf("%s working set size: %llu free items: %u\n",
532 zone->uz_name, (unsigned long long)zone->uz_wssize, zone->uz_free);
533#endif
|
528 extra = zone->uz_wssize - zone->uz_free;
|
| 534 extra = zone->uz_free - zone->uz_wssize; |
535 extra /= zone->uz_ipers;
536
537 /* extra is now the number of extra slabs that we can free */
538
539 if (extra == 0)
540 goto finished;
541
542 slab = LIST_FIRST(&zone->uz_free_slab);
543 while (slab && extra) {
544 n = LIST_NEXT(slab, us_link);
545
546 /* We have no where to free these to */
547 if (slab->us_flags & UMA_SLAB_BOOT) {
548 slab = n;
549 continue;
550 }
551
552 LIST_REMOVE(slab, us_link);
553 zone->uz_pages -= zone->uz_ppera;
554 zone->uz_free -= zone->uz_ipers;
555 if (zone->uz_fini)
556 for (i = 0; i < zone->uz_ipers; i++)
557 zone->uz_fini(
558 slab->us_data + (zone->uz_rsize * i),
559 zone->uz_size);
560 flags = slab->us_flags;
561 mem = slab->us_data;
562 if (zone->uz_flags & UMA_ZFLAG_OFFPAGE) {
563 if (zone->uz_flags & UMA_ZFLAG_MALLOC) {
564 UMA_HASH_REMOVE(mallochash,
565 slab, slab->us_data);
566 } else {
567 UMA_HASH_REMOVE(&zone->uz_hash,
568 slab, slab->us_data);
569 }
570 uma_zfree_internal(slabzone, slab, NULL, 0);
571 } else if (zone->uz_flags & UMA_ZFLAG_MALLOC)
572 UMA_HASH_REMOVE(mallochash, slab, slab->us_data);
573#ifdef UMA_DEBUG
574 printf("%s: Returning %d bytes.\n",
575 zone->uz_name, UMA_SLAB_SIZE * zone->uz_ppera);
576#endif
577 zone->uz_freef(mem, UMA_SLAB_SIZE * zone->uz_ppera, flags);
578
579 slab = n;
580 extra--;
581 }
582
583finished:
584 ZONE_UNLOCK(zone);
585}
586
587/*
588 * Allocate a new slab for a zone. This does not insert the slab onto a list.
589 *
590 * Arguments:
591 * zone The zone to allocate slabs for
592 * wait Shall we wait?
593 *
594 * Returns:
595 * The slab that was allocated or NULL if there is no memory and the
596 * caller specified M_NOWAIT.
597 *
598 */
599static uma_slab_t
600slab_zalloc(uma_zone_t zone, int wait)
601{
602 uma_slab_t slab; /* Starting slab */
603 u_int8_t *mem;
604 u_int8_t flags;
605 int i;
606
607 slab = NULL;
608
609#ifdef UMA_DEBUG
610 printf("slab_zalloc: Allocating a new slab for %s\n", zone->uz_name);
611#endif
612 if (zone->uz_maxpages &&
613 zone->uz_pages + zone->uz_ppera > zone->uz_maxpages)
614 return (NULL);
615
616 ZONE_UNLOCK(zone);
617
618 if (zone->uz_flags & UMA_ZFLAG_OFFPAGE) {
619 slab = uma_zalloc_internal(slabzone, NULL, wait, NULL);
620 if (slab == NULL) {
621 ZONE_LOCK(zone);
622 return NULL;
623 }
624 }
625
626 if (booted || (zone->uz_flags & UMA_ZFLAG_PRIVALLOC)) {
627 mtx_lock(&Giant);
628 mem = zone->uz_allocf(zone,
629 zone->uz_ppera * UMA_SLAB_SIZE, &flags, wait);
630 mtx_unlock(&Giant);
631 if (mem == NULL) {
632 ZONE_LOCK(zone);
633 return (NULL);
634 }
635 } else {
636 uma_slab_t tmps;
637
638 if (zone->uz_ppera > 1)
639 panic("UMA: Attemping to allocate multiple pages before vm has started.\n");
640 if (zone->uz_flags & UMA_ZFLAG_MALLOC)
641 panic("Mallocing before uma_startup2 has been called.\n");
642 if (uma_boot_free == 0)
643 panic("UMA: Ran out of pre init pages, increase UMA_BOOT_PAGES\n");
644 tmps = LIST_FIRST(&uma_boot_pages);
645 LIST_REMOVE(tmps, us_link);
646 uma_boot_free--;
647 mem = tmps->us_data;
648 }
649
650 ZONE_LOCK(zone);
651
652 /* Alloc slab structure for offpage, otherwise adjust it's position */
653 if (!(zone->uz_flags & UMA_ZFLAG_OFFPAGE)) {
654 slab = (uma_slab_t )(mem + zone->uz_pgoff);
655 } else {
656 if (!(zone->uz_flags & UMA_ZFLAG_MALLOC))
657 UMA_HASH_INSERT(&zone->uz_hash, slab, mem);
658 }
659 if (zone->uz_flags & UMA_ZFLAG_MALLOC) {
660#ifdef UMA_DEBUG
661 printf("Inserting %p into malloc hash from slab %p\n",
662 mem, slab);
663#endif
664 /* XXX Yikes! No lock on the malloc hash! */
665 UMA_HASH_INSERT(mallochash, slab, mem);
666 }
667
668 slab->us_zone = zone;
669 slab->us_data = mem;
670
671 /*
672 * This is intended to spread data out across cache lines.
673 *
674 * This code doesn't seem to work properly on x86, and on alpha
675 * it makes absolutely no performance difference. I'm sure it could
676 * use some tuning, but sun makes outrageous claims about it's
677 * performance.
678 */
679#if 0
680 if (zone->uz_cachemax) {
681 slab->us_data += zone->uz_cacheoff;
682 zone->uz_cacheoff += UMA_CACHE_INC;
683 if (zone->uz_cacheoff > zone->uz_cachemax)
684 zone->uz_cacheoff = 0;
685 }
686#endif
687
688 slab->us_freecount = zone->uz_ipers;
689 slab->us_firstfree = 0;
690 slab->us_flags = flags;
691 for (i = 0; i < zone->uz_ipers; i++)
692 slab->us_freelist[i] = i+1;
693
694 if (zone->uz_init)
695 for (i = 0; i < zone->uz_ipers; i++)
696 zone->uz_init(slab->us_data + (zone->uz_rsize * i),
697 zone->uz_size);
698
699 zone->uz_pages += zone->uz_ppera;
700 zone->uz_free += zone->uz_ipers;
701
702 return (slab);
703}
704
705/*
706 * Allocates a number of pages from the system
707 *
708 * Arguments:
709 * zone Unused
710 * bytes The number of bytes requested
711 * wait Shall we wait?
712 *
713 * Returns:
714 * A pointer to the alloced memory or possibly
715 * NULL if M_NOWAIT is set.
716 */
717static void *
718page_alloc(uma_zone_t zone, int bytes, u_int8_t *pflag, int wait)
719{
720 void *p; /* Returned page */
721
722 /*
723 * XXX The original zone allocator did this, but I don't think it's
724 * necessary in current.
725 */
726
727 if (lockstatus(&kernel_map->lock, NULL)) {
728 *pflag = UMA_SLAB_KMEM;
729 p = (void *) kmem_malloc(kmem_map, bytes, wait);
730 } else {
731 *pflag = UMA_SLAB_KMAP;
732 p = (void *) kmem_alloc(kernel_map, bytes);
733 }
734
735 return (p);
736}
737
738/*
739 * Allocates a number of pages from within an object
740 *
741 * Arguments:
742 * zone Unused
743 * bytes The number of bytes requested
744 * wait Shall we wait?
745 *
746 * Returns:
747 * A pointer to the alloced memory or possibly
748 * NULL if M_NOWAIT is set.
749 */
750static void *
751obj_alloc(uma_zone_t zone, int bytes, u_int8_t *flags, int wait)
752{
753 vm_offset_t zkva;
754 vm_offset_t retkva;
755 vm_page_t p;
756 int pages;
757
758 retkva = NULL;
759 pages = zone->uz_pages;
760
761 /*
762 * This looks a little weird since we're getting one page at a time
763 */
764 while (bytes > 0) {
765 p = vm_page_alloc(zone->uz_obj, pages,
766 VM_ALLOC_INTERRUPT);
767 if (p == NULL)
768 return (NULL);
769
770 zkva = zone->uz_kva + pages * PAGE_SIZE;
771 if (retkva == NULL)
772 retkva = zkva;
773 pmap_qenter(zkva, &p, 1);
774 bytes -= PAGE_SIZE;
775 pages += 1;
776 }
777
778 *flags = UMA_SLAB_PRIV;
779
780 return ((void *)retkva);
781}
782
783/*
784 * Frees a number of pages to the system
785 *
786 * Arguments:
787 * mem A pointer to the memory to be freed
788 * size The size of the memory being freed
789 * flags The original p->us_flags field
790 *
791 * Returns:
792 * Nothing
793 *
794 */
795static void
796page_free(void *mem, int size, u_int8_t flags)
797{
798 vm_map_t map;
799 if (flags & UMA_SLAB_KMEM)
800 map = kmem_map;
801 else if (flags & UMA_SLAB_KMAP)
802 map = kernel_map;
803 else
804 panic("UMA: page_free used with invalid flags %d\n", flags);
805
806 kmem_free(map, (vm_offset_t)mem, size);
807}
808
809/*
810 * Zero fill initializer
811 *
812 * Arguments/Returns follow uma_init specifications
813 *
814 */
815static void
816zero_init(void *mem, int size)
817{
818 bzero(mem, size);
819}
820
821/*
822 * Finish creating a small uma zone. This calculates ipers, and the zone size.
823 *
824 * Arguments
825 * zone The zone we should initialize
826 *
827 * Returns
828 * Nothing
829 */
830static void
831zone_small_init(uma_zone_t zone)
832{
833 int rsize;
834 int memused;
835 int ipers;
836
837 rsize = zone->uz_size;
838
839 if (rsize < UMA_SMALLEST_UNIT)
840 rsize = UMA_SMALLEST_UNIT;
841
842 if (rsize & zone->uz_align)
843 rsize = (rsize & ~zone->uz_align) + (zone->uz_align + 1);
844
845 zone->uz_rsize = rsize;
846
847 rsize += 1; /* Account for the byte of linkage */
848 zone->uz_ipers = (UMA_SLAB_SIZE - sizeof(struct uma_slab)) / rsize;
849 zone->uz_ppera = 1;
850
851 memused = zone->uz_ipers * zone->uz_rsize;
852
853 /* Can we do any better? */
854 if ((UMA_SLAB_SIZE - memused) >= UMA_MAX_WASTE) {
855 if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
856 return;
857 ipers = UMA_SLAB_SIZE / zone->uz_rsize;
858 if (ipers > zone->uz_ipers) {
859 zone->uz_flags |= UMA_ZFLAG_OFFPAGE;
860 zone->uz_ipers = ipers;
861 }
862 }
863
864}
865
866/*
867 * Finish creating a large (> UMA_SLAB_SIZE) uma zone. Just give in and do
868 * OFFPAGE for now. When I can allow for more dynamic slab sizes this will be
869 * more complicated.
870 *
871 * Arguments
872 * zone The zone we should initialize
873 *
874 * Returns
875 * Nothing
876 */
877static void
878zone_large_init(uma_zone_t zone)
879{
880 int pages;
881
882 pages = zone->uz_size / UMA_SLAB_SIZE;
883
884 /* Account for remainder */
885 if ((pages * UMA_SLAB_SIZE) < zone->uz_size)
886 pages++;
887
888 zone->uz_ppera = pages;
889 zone->uz_ipers = 1;
890
891 zone->uz_flags |= UMA_ZFLAG_OFFPAGE;
892 zone->uz_rsize = zone->uz_size;
893}
894
895/*
896 * Zone header ctor. This initializes all fields, locks, etc. And inserts
897 * the zone onto the global zone list.
898 *
899 * Arguments/Returns follow uma_ctor specifications
900 * udata Actually uma_zcreat_args
901 *
902 */
903
904static void
905zone_ctor(void *mem, int size, void *udata)
906{
907 struct uma_zctor_args *arg = udata;
908 uma_zone_t zone = mem;
909 int cplen;
910 int cpu;
911
912 bzero(zone, size);
913 zone->uz_name = arg->name;
914 zone->uz_size = arg->size;
915 zone->uz_ctor = arg->ctor;
916 zone->uz_dtor = arg->dtor;
917 zone->uz_init = arg->uminit;
918 zone->uz_align = arg->align;
919 zone->uz_free = 0;
920 zone->uz_pages = 0;
921 zone->uz_flags = 0;
922 zone->uz_allocf = page_alloc;
923 zone->uz_freef = page_free;
924
925 if (arg->flags & UMA_ZONE_ZINIT)
926 zone->uz_init = zero_init;
927
928 if (arg->flags & UMA_ZONE_INTERNAL)
929 zone->uz_flags |= UMA_ZFLAG_INTERNAL;
930
931 if (arg->flags & UMA_ZONE_MALLOC)
932 zone->uz_flags |= UMA_ZFLAG_MALLOC;
933
934 if (arg->flags & UMA_ZONE_NOFREE)
935 zone->uz_flags |= UMA_ZFLAG_NOFREE;
936
937 if (zone->uz_size > UMA_SLAB_SIZE)
938 zone_large_init(zone);
939 else
940 zone_small_init(zone);
941
942 /* We do this so that the per cpu lock name is unique for each zone */
943 memcpy(zone->uz_lname, "PCPU ", 5);
944 cplen = min(strlen(zone->uz_name) + 1, LOCKNAME_LEN - 6);
945 memcpy(zone->uz_lname+5, zone->uz_name, cplen);
946 zone->uz_lname[LOCKNAME_LEN - 1] = '\0';
947
948 /*
949 * If we're putting the slab header in the actual page we need to
950 * figure out where in each page it goes. This calculates a right
951 * justified offset into the memory on a ALIGN_PTR boundary.
952 */
953 if (!(zone->uz_flags & UMA_ZFLAG_OFFPAGE)) {
954 int totsize;
955 int waste;
956
957 /* Size of the slab struct and free list */
958 totsize = sizeof(struct uma_slab) + zone->uz_ipers;
959 if (totsize & UMA_ALIGN_PTR)
960 totsize = (totsize & ~UMA_ALIGN_PTR) +
961 (UMA_ALIGN_PTR + 1);
962 zone->uz_pgoff = UMA_SLAB_SIZE - totsize;
963
964 waste = zone->uz_pgoff;
965 waste -= (zone->uz_ipers * zone->uz_rsize);
966
967 /*
968 * This calculates how much space we have for cache line size
969 * optimizations. It works by offseting each slab slightly.
970 * Currently it breaks on x86, and so it is disabled.
971 */
972
973 if (zone->uz_align < UMA_CACHE_INC && waste > UMA_CACHE_INC) {
974 zone->uz_cachemax = waste - UMA_CACHE_INC;
975 zone->uz_cacheoff = 0;
976 }
977
978 totsize = zone->uz_pgoff + sizeof(struct uma_slab)
979 + zone->uz_ipers;
980 /* I don't think it's possible, but I'll make sure anyway */
981 if (totsize > UMA_SLAB_SIZE) {
982 printf("zone %s ipers %d rsize %d size %d\n",
983 zone->uz_name, zone->uz_ipers, zone->uz_rsize,
984 zone->uz_size);
985 panic("UMA slab won't fit.\n");
986 }
987 } else {
988 /* hash_expand here to allocate the initial hash table */
989 hash_expand(&zone->uz_hash);
990 zone->uz_pgoff = 0;
991 }
992
993#ifdef UMA_DEBUG
994 printf("%s(%p) size = %d ipers = %d ppera = %d pgoff = %d\n",
995 zone->uz_name, zone,
996 zone->uz_size, zone->uz_ipers,
997 zone->uz_ppera, zone->uz_pgoff);
998#endif
999 ZONE_LOCK_INIT(zone);
1000
1001 mtx_lock(&uma_mtx);
1002 LIST_INSERT_HEAD(&uma_zones, zone, uz_link);
1003 mtx_unlock(&uma_mtx);
1004
1005 /*
1006 * Some internal zones don't have room allocated for the per cpu
1007 * caches. If we're internal, bail out here.
1008 */
1009
1010 if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
1011 return;
1012
1013 if (zone->uz_ipers < UMA_BUCKET_SIZE)
1014 zone->uz_count = zone->uz_ipers - 1;
1015 else
1016 zone->uz_count = UMA_BUCKET_SIZE - 1;
1017
1018 for (cpu = 0; cpu < maxcpu; cpu++)
1019 CPU_LOCK_INIT(zone, cpu);
1020}
1021
|
1022/*
1023 * Zone header dtor. This frees all data, destroys locks, frees the hash table
1024 * and removes the zone from the global list.
1025 *
1026 * Arguments/Returns follow uma_dtor specifications
1027 * udata unused
1028 */
1029
1030static void
1031zone_dtor(void *arg, int size, void *udata)
1032{
1033 uma_zone_t zone;
1034 int cpu;
1035
1036 zone = (uma_zone_t)arg;
1037
1038 mtx_lock(&uma_mtx);
1039 LIST_REMOVE(zone, uz_link);
1040 mtx_unlock(&uma_mtx);
1041
1042 ZONE_LOCK(zone);
1043 zone->uz_wssize = 0;
1044 ZONE_UNLOCK(zone);
1045
1046 zone_drain(zone);
1047 ZONE_LOCK(zone);
1048 if (zone->uz_free != 0)
1049 printf("Zone %s was not empty. Lost %d pages of memory.\n",
1050 zone->uz_name, zone->uz_pages);
1051
1052 if ((zone->uz_flags & UMA_ZFLAG_INTERNAL) != 0)
1053 for (cpu = 0; cpu < maxcpu; cpu++)
1054 CPU_LOCK_FINI(zone, cpu);
1055
1056 if ((zone->uz_flags & UMA_ZFLAG_OFFPAGE) != 0)
1057 hash_free(&zone->uz_hash);
1058
1059 ZONE_UNLOCK(zone);
1060 ZONE_LOCK_FINI(zone);
1061} |
1062/*
1063 * Traverses every zone in the system and calls a callback
1064 *
1065 * Arguments:
1066 * zfunc A pointer to a function which accepts a zone
1067 * as an argument.
1068 *
1069 * Returns:
1070 * Nothing
1071 */
1072static void
1073zone_foreach(void (*zfunc)(uma_zone_t))
1074{
1075 uma_zone_t zone;
1076
1077 mtx_lock(&uma_mtx);
1078 LIST_FOREACH(zone, &uma_zones, uz_link) {
1079 zfunc(zone);
1080 }
1081 mtx_unlock(&uma_mtx);
1082}
1083
1084/* Public functions */
1085/* See uma.h */
1086void
1087uma_startup(void *bootmem)
1088{
1089 struct uma_zctor_args args;
1090 uma_slab_t slab;
1091 int slabsize;
1092 int i;
1093
1094#ifdef UMA_DEBUG
1095 printf("Creating uma zone headers zone.\n");
1096#endif
1097#ifdef SMP
1098 maxcpu = mp_maxid + 1;
1099#else
1100 maxcpu = 1;
1101#endif
1102#ifdef UMA_DEBUG
1103 printf("Max cpu = %d, mp_maxid = %d\n", maxcpu, mp_maxid);
1104 Debugger("stop");
1105#endif
1106 mtx_init(&uma_mtx, "UMA lock", NULL, MTX_DEF);
1107 /* "manually" Create the initial zone */
1108 args.name = "UMA Zones";
1109 args.size = sizeof(struct uma_zone) +
1110 (sizeof(struct uma_cache) * (maxcpu - 1));
1111 args.ctor = zone_ctor;
|
1066 args.dtor = NULL;
|
| 1112 args.dtor = zone_dtor; |
1113 args.uminit = zero_init;
1114 args.fini = NULL;
1115 args.align = 32 - 1;
1116 args.flags = UMA_ZONE_INTERNAL;
1117 /* The initial zone has no Per cpu queues so it's smaller */
1118 zone_ctor(zones, sizeof(struct uma_zone), &args);
1119
1120#ifdef UMA_DEBUG
1121 printf("Filling boot free list.\n");
1122#endif
1123 for (i = 0; i < UMA_BOOT_PAGES; i++) {
1124 slab = (uma_slab_t)((u_int8_t *)bootmem + (i * UMA_SLAB_SIZE));
1125 slab->us_data = (u_int8_t *)slab;
1126 slab->us_flags = UMA_SLAB_BOOT;
1127 LIST_INSERT_HEAD(&uma_boot_pages, slab, us_link);
1128 uma_boot_free++;
1129 }
1130
1131#ifdef UMA_DEBUG
1132 printf("Creating slab zone.\n");
1133#endif
1134
1135 /*
1136 * This is the max number of free list items we'll have with
1137 * offpage slabs.
1138 */
1139
1140 slabsize = UMA_SLAB_SIZE - sizeof(struct uma_slab);
1141 slabsize /= UMA_MAX_WASTE;
1142 slabsize++; /* In case there it's rounded */
1143 slabsize += sizeof(struct uma_slab);
1144
1145 /* Now make a zone for slab headers */
1146 slabzone = uma_zcreate("UMA Slabs",
1147 slabsize,
1148 NULL, NULL, NULL, NULL,
1149 UMA_ALIGN_PTR, UMA_ZONE_INTERNAL);
1150
1151 hashzone = uma_zcreate("UMA Hash",
1152 sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT,
1153 NULL, NULL, NULL, NULL,
1154 UMA_ALIGN_PTR, UMA_ZONE_INTERNAL);
1155
1156 bucketzone = uma_zcreate("UMA Buckets", sizeof(struct uma_bucket),
1157 NULL, NULL, NULL, NULL,
1158 UMA_ALIGN_PTR, UMA_ZONE_INTERNAL);
1159
1160
1161#ifdef UMA_DEBUG
1162 printf("UMA startup complete.\n");
1163#endif
1164}
1165
1166/* see uma.h */
1167void
1168uma_startup2(void *hashmem, u_long elems)
1169{
1170 bzero(hashmem, elems * sizeof(void *));
1171 mallochash->uh_slab_hash = hashmem;
1172 mallochash->uh_hashsize = elems;
1173 mallochash->uh_hashmask = elems - 1;
1174 booted = 1;
1175#ifdef UMA_DEBUG
1176 printf("UMA startup2 complete.\n");
1177#endif
1178}
1179
1180/*
1181 * Initialize our callout handle
1182 *
1183 */
1184
1185static void
1186uma_startup3(void)
1187{
1188#ifdef UMA_DEBUG
1189 printf("Starting callout.\n");
1190#endif
1191 /* We'll be mpsafe once the vm is locked. */
1192 callout_init(&uma_callout, 0);
1193 callout_reset(&uma_callout, UMA_WORKING_TIME * hz, uma_timeout, NULL);
1194#ifdef UMA_DEBUG
1195 printf("UMA startup3 complete.\n");
1196#endif
1197}
1198
1199/* See uma.h */
1200uma_zone_t
1201uma_zcreate(char *name, int size, uma_ctor ctor, uma_dtor dtor, uma_init uminit,
1202 uma_fini fini, int align, u_int16_t flags)
1203
1204{
1205 struct uma_zctor_args args;
1206
1207 /* This stuff is essential for the zone ctor */
1208 args.name = name;
1209 args.size = size;
1210 args.ctor = ctor;
1211 args.dtor = dtor;
1212 args.uminit = uminit;
1213 args.fini = fini;
1214 args.align = align;
1215 args.flags = flags;
1216
1217 return (uma_zalloc_internal(zones, &args, M_WAITOK, NULL));
1218}
1219
1220/* See uma.h */
|
1221void
1222uma_zdestroy(uma_zone_t zone)
1223{
1224 uma_zfree_internal(zones, zone, NULL, 0);
1225}
1226
1227/* See uma.h */ |
1228void *
1229uma_zalloc_arg(uma_zone_t zone, void *udata, int wait)
1230{
1231 void *item;
1232 uma_cache_t cache;
1233 uma_bucket_t bucket;
1234 int cpu;
1235
1236 /* This is the fast path allocation */
1237#ifdef UMA_DEBUG_ALLOC_1
1238 printf("Allocating one item from %s(%p)\n", zone->uz_name, zone);
1239#endif
1240
1241zalloc_restart:
1242 cpu = PCPU_GET(cpuid);
1243 CPU_LOCK(zone, cpu);
1244 cache = &zone->uz_cpu[cpu];
1245
1246zalloc_start:
1247 bucket = cache->uc_allocbucket;
1248
1249 if (bucket) {
1250 if (bucket->ub_ptr > -1) {
1251 item = bucket->ub_bucket[bucket->ub_ptr];
1252#ifdef INVARIANTS
1253 bucket->ub_bucket[bucket->ub_ptr] = NULL;
1254#endif
1255 bucket->ub_ptr--;
1256 KASSERT(item != NULL,
1257 ("uma_zalloc: Bucket pointer mangled."));
1258 cache->uc_allocs++;
1259 CPU_UNLOCK(zone, cpu);
1260 if (zone->uz_ctor)
1261 zone->uz_ctor(item, zone->uz_size, udata);
1262 return (item);
1263 } else if (cache->uc_freebucket) {
1264 /*
1265 * We have run out of items in our allocbucket.
1266 * See if we can switch with our free bucket.
1267 */
1268 if (cache->uc_freebucket->ub_ptr > -1) {
1269 uma_bucket_t swap;
1270
1271#ifdef UMA_DEBUG_ALLOC
1272 printf("uma_zalloc: Swapping empty with alloc.\n");
1273#endif
1274 swap = cache->uc_freebucket;
1275 cache->uc_freebucket = cache->uc_allocbucket;
1276 cache->uc_allocbucket = swap;
1277
1278 goto zalloc_start;
1279 }
1280 }
1281 }
1282 ZONE_LOCK(zone);
1283 /* Since we have locked the zone we may as well send back our stats */
1284 zone->uz_allocs += cache->uc_allocs;
1285 cache->uc_allocs = 0;
1286
1287 /* Our old one is now a free bucket */
1288 if (cache->uc_allocbucket) {
1289 KASSERT(cache->uc_allocbucket->ub_ptr == -1,
1290 ("uma_zalloc_arg: Freeing a non free bucket."));
1291 LIST_INSERT_HEAD(&zone->uz_free_bucket,
1292 cache->uc_allocbucket, ub_link);
1293 cache->uc_allocbucket = NULL;
1294 }
1295
1296 /* Check the free list for a new alloc bucket */
1297 if ((bucket = LIST_FIRST(&zone->uz_full_bucket)) != NULL) {
1298 KASSERT(bucket->ub_ptr != -1,
1299 ("uma_zalloc_arg: Returning an empty bucket."));
1300
1301 LIST_REMOVE(bucket, ub_link);
1302 cache->uc_allocbucket = bucket;
1303 ZONE_UNLOCK(zone);
1304 goto zalloc_start;
1305 }
1306 /* Bump up our uz_count so we get here less */
1307 if (zone->uz_count < UMA_BUCKET_SIZE - 1)
1308 zone->uz_count++;
1309
1310 /* We are no longer associated with this cpu!!! */
1311 CPU_UNLOCK(zone, cpu);
1312
1313 /*
1314 * Now lets just fill a bucket and put it on the free list. If that
1315 * works we'll restart the allocation from the begining.
1316 *
1317 * Try this zone's free list first so we don't allocate extra buckets.
1318 */
1319
1320 if ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL)
1321 LIST_REMOVE(bucket, ub_link);
1322
1323 /* Now we no longer need the zone lock. */
1324 ZONE_UNLOCK(zone);
1325
1326 if (bucket == NULL)
1327 bucket = uma_zalloc_internal(bucketzone,
1328 NULL, wait, NULL);
1329
1330 if (bucket != NULL) {
1331#ifdef INVARIANTS
1332 bzero(bucket, bucketzone->uz_size);
1333#endif
1334 bucket->ub_ptr = -1;
1335
1336 if (uma_zalloc_internal(zone, udata, wait, bucket))
1337 goto zalloc_restart;
1338 else
1339 uma_zfree_internal(bucketzone, bucket, NULL, 0);
1340 }
1341 /*
1342 * We may not get a bucket if we recurse, so
1343 * return an actual item.
1344 */
1345#ifdef UMA_DEBUG
1346 printf("uma_zalloc_arg: Bucketzone returned NULL\n");
1347#endif
1348
1349 return (uma_zalloc_internal(zone, udata, wait, NULL));
1350}
1351
1352/*
1353 * Allocates an item for an internal zone OR fills a bucket
1354 *
1355 * Arguments
1356 * zone The zone to alloc for.
1357 * udata The data to be passed to the constructor.
1358 * wait M_WAITOK or M_NOWAIT.
1359 * bucket The bucket to fill or NULL
1360 *
1361 * Returns
1362 * NULL if there is no memory and M_NOWAIT is set
1363 * An item if called on an interal zone
1364 * Non NULL if called to fill a bucket and it was successful.
1365 *
1366 * Discussion:
1367 * This was much cleaner before it had to do per cpu caches. It is
1368 * complicated now because it has to handle the simple internal case, and
1369 * the more involved bucket filling and allocation.
1370 */
1371
1372static void *
1373uma_zalloc_internal(uma_zone_t zone, void *udata, int wait, uma_bucket_t bucket)
1374{
1375 uma_slab_t slab;
1376 u_int8_t freei;
1377 void *item;
1378
1379 item = NULL;
1380
1381 /*
1382 * This is to stop us from allocating per cpu buckets while we're
1383 * running out of UMA_BOOT_PAGES. Otherwise, we would exhaust the
1384 * boot pages.
1385 */
1386
1387 if (!booted && zone == bucketzone)
1388 return (NULL);
1389
1390#ifdef UMA_DEBUG_ALLOC
1391 printf("INTERNAL: Allocating one item from %s(%p)\n", zone->uz_name, zone);
1392#endif
1393 ZONE_LOCK(zone);
1394
1395 /*
1396 * This code is here to limit the number of simultaneous bucket fills
1397 * for any given zone to the number of per cpu caches in this zone. This
1398 * is done so that we don't allocate more memory than we really need.
1399 */
1400
1401 if (bucket) {
1402#ifdef SMP
1403 if (zone->uz_fills >= mp_ncpus)
1404#else
1405 if (zone->uz_fills > 1)
1406#endif
1407 return (NULL);
1408
1409 zone->uz_fills++;
1410 }
1411
1412new_slab:
1413
1414 /* Find a slab with some space */
1415 if (zone->uz_free) {
1416 if (!LIST_EMPTY(&zone->uz_part_slab)) {
1417 slab = LIST_FIRST(&zone->uz_part_slab);
1418 } else {
1419 slab = LIST_FIRST(&zone->uz_free_slab);
1420 LIST_REMOVE(slab, us_link);
1421 LIST_INSERT_HEAD(&zone->uz_part_slab, slab, us_link);
1422 }
1423 } else {
1424 /*
1425 * This is to prevent us from recursively trying to allocate
1426 * buckets. The problem is that if an allocation forces us to
1427 * grab a new bucket we will call page_alloc, which will go off
1428 * and cause the vm to allocate vm_map_entries. If we need new
1429 * buckets there too we will recurse in kmem_alloc and bad
1430 * things happen. So instead we return a NULL bucket, and make
1431 * the code that allocates buckets smart enough to deal with it */
1432 if (zone == bucketzone && zone->uz_recurse != 0) {
1433 ZONE_UNLOCK(zone);
1434 return (NULL);
1435 }
1436 zone->uz_recurse++;
1437 slab = slab_zalloc(zone, wait);
1438 zone->uz_recurse--;
1439 if (slab) {
1440 LIST_INSERT_HEAD(&zone->uz_part_slab, slab, us_link);
1441 /*
1442 * We might not have been able to get a page, but another cpu
1443 * could have while we were unlocked.
1444 */
1445 } else if (zone->uz_free == 0) {
1446 /* If we're filling a bucket return what we have */
1447 if (bucket != NULL)
1448 zone->uz_fills--;
1449 ZONE_UNLOCK(zone);
1450
1451 if (bucket != NULL && bucket->ub_ptr != -1)
1452 return (bucket);
1453 else
1454 return (NULL);
1455 } else {
1456 /* Another cpu must have succeeded */
1457 if ((slab = LIST_FIRST(&zone->uz_part_slab)) == NULL) {
1458 slab = LIST_FIRST(&zone->uz_free_slab);
1459 LIST_REMOVE(slab, us_link);
1460 LIST_INSERT_HEAD(&zone->uz_part_slab,
1461 slab, us_link);
1462 }
1463 }
1464 }
1465 /*
1466 * If this is our first time though put this guy on the list.
1467 */
1468 if (bucket != NULL && bucket->ub_ptr == -1)
1469 LIST_INSERT_HEAD(&zone->uz_full_bucket,
1470 bucket, ub_link);
1471
1472
1473 while (slab->us_freecount) {
1474 freei = slab->us_firstfree;
1475 slab->us_firstfree = slab->us_freelist[freei];
1476#ifdef INVARIANTS
1477 slab->us_freelist[freei] = 255;
1478#endif
1479 slab->us_freecount--;
1480 zone->uz_free--;
1481 item = slab->us_data + (zone->uz_rsize * freei);
1482
1483 if (bucket == NULL) {
1484 zone->uz_allocs++;
1485 break;
1486 }
1487 bucket->ub_bucket[++bucket->ub_ptr] = item;
1488
1489 /* Don't overfill the bucket! */
1490 if (bucket->ub_ptr == zone->uz_count)
1491 break;
1492 }
1493
1494 /* Move this slab to the full list */
1495 if (slab->us_freecount == 0) {
1496 LIST_REMOVE(slab, us_link);
1497 LIST_INSERT_HEAD(&zone->uz_full_slab, slab, us_link);
1498 }
1499
1500 if (bucket != NULL) {
1501 /* Try to keep the buckets totally full, but don't block */
1502 if (bucket->ub_ptr < zone->uz_count) {
1503 wait = M_NOWAIT;
1504 goto new_slab;
1505 } else
1506 zone->uz_fills--;
1507 }
1508
1509 ZONE_UNLOCK(zone);
1510
1511 /* Only construct at this time if we're not filling a bucket */
1512 if (bucket == NULL && zone->uz_ctor != NULL)
1513 zone->uz_ctor(item, zone->uz_size, udata);
1514
1515 return (item);
1516}
1517
1518/* See uma.h */
1519void
1520uma_zfree_arg(uma_zone_t zone, void *item, void *udata)
1521{
1522 uma_cache_t cache;
1523 uma_bucket_t bucket;
1524 int cpu;
1525
1526 /* This is the fast path free */
1527#ifdef UMA_DEBUG_ALLOC_1
1528 printf("Freeing item %p to %s(%p)\n", item, zone->uz_name, zone);
1529#endif
1530zfree_restart:
1531 cpu = PCPU_GET(cpuid);
1532 CPU_LOCK(zone, cpu);
1533 cache = &zone->uz_cpu[cpu];
1534
1535zfree_start:
1536 bucket = cache->uc_freebucket;
1537
1538 if (bucket) {
1539 /*
1540 * Do we have room in our bucket? It is OK for this uz count
1541 * check to be slightly out of sync.
1542 */
1543
1544 if (bucket->ub_ptr < zone->uz_count) {
1545 bucket->ub_ptr++;
1546 KASSERT(bucket->ub_bucket[bucket->ub_ptr] == NULL,
1547 ("uma_zfree: Freeing to non free bucket index."));
1548 bucket->ub_bucket[bucket->ub_ptr] = item;
1549 CPU_UNLOCK(zone, cpu);
1550 if (zone->uz_dtor)
1551 zone->uz_dtor(item, zone->uz_size, udata);
1552 return;
1553 } else if (cache->uc_allocbucket) {
1554#ifdef UMA_DEBUG_ALLOC
1555 printf("uma_zfree: Swapping buckets.\n");
1556#endif
1557 /*
1558 * We have run out of space in our freebucket.
1559 * See if we can switch with our alloc bucket.
1560 */
1561 if (cache->uc_allocbucket->ub_ptr <
1562 cache->uc_freebucket->ub_ptr) {
1563 uma_bucket_t swap;
1564
1565 swap = cache->uc_freebucket;
1566 cache->uc_freebucket = cache->uc_allocbucket;
1567 cache->uc_allocbucket = swap;
1568
1569 goto zfree_start;
1570 }
1571 }
1572 }
1573
1574 /*
1575 * We can get here for two reasons:
1576 *
1577 * 1) The buckets are NULL
1578 * 2) The alloc and free buckets are both somewhat full.
1579 *
1580 */
1581
1582 ZONE_LOCK(zone);
1583
1584 bucket = cache->uc_freebucket;
1585 cache->uc_freebucket = NULL;
1586
1587 /* Can we throw this on the zone full list? */
1588 if (bucket != NULL) {
1589#ifdef UMA_DEBUG_ALLOC
1590 printf("uma_zfree: Putting old bucket on the free list.\n");
1591#endif
1592 /* ub_ptr is pointing to the last free item */
1593 KASSERT(bucket->ub_ptr != -1,
1594 ("uma_zfree: Attempting to insert an empty bucket onto the full list.\n"));
1595 LIST_INSERT_HEAD(&zone->uz_full_bucket,
1596 bucket, ub_link);
1597 }
1598 if ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) {
1599 LIST_REMOVE(bucket, ub_link);
1600 ZONE_UNLOCK(zone);
1601 cache->uc_freebucket = bucket;
1602 goto zfree_start;
1603 }
1604 /* We're done with this CPU now */
1605 CPU_UNLOCK(zone, cpu);
1606
1607 /* And the zone.. */
1608 ZONE_UNLOCK(zone);
1609
1610#ifdef UMA_DEBUG_ALLOC
1611 printf("uma_zfree: Allocating new free bucket.\n");
1612#endif
1613 bucket = uma_zalloc_internal(bucketzone,
1614 NULL, M_NOWAIT, NULL);
1615 if (bucket) {
1616#ifdef INVARIANTS
1617 bzero(bucket, bucketzone->uz_size);
1618#endif
1619 bucket->ub_ptr = -1;
1620 ZONE_LOCK(zone);
1621 LIST_INSERT_HEAD(&zone->uz_free_bucket,
1622 bucket, ub_link);
1623 ZONE_UNLOCK(zone);
1624 goto zfree_restart;
1625 }
1626
1627 /*
1628 * If nothing else caught this, we'll just do an internal free.
1629 */
1630
1631 uma_zfree_internal(zone, item, udata, 0);
1632
1633 return;
1634
1635}
1636
1637/*
1638 * Frees an item to an INTERNAL zone or allocates a free bucket
1639 *
1640 * Arguments:
1641 * zone The zone to free to
1642 * item The item we're freeing
1643 * udata User supplied data for the dtor
1644 * skip Skip the dtor, it was done in uma_zfree_arg
1645 */
1646
1647static void
1648uma_zfree_internal(uma_zone_t zone, void *item, void *udata, int skip)
1649{
1650 uma_slab_t slab;
1651 u_int8_t *mem;
1652 u_int8_t freei;
1653
1654 ZONE_LOCK(zone);
1655
1656 if (!(zone->uz_flags & UMA_ZFLAG_MALLOC)) {
1657 mem = (u_int8_t *)((unsigned long)item & (~UMA_SLAB_MASK));
1658 if (zone->uz_flags & UMA_ZFLAG_OFFPAGE)
1659 slab = hash_sfind(&zone->uz_hash, mem);
1660 else {
1661 mem += zone->uz_pgoff;
1662 slab = (uma_slab_t)mem;
1663 }
1664 } else {
1665 slab = (uma_slab_t)udata;
1666 }
1667
1668 /* Do we need to remove from any lists? */
1669 if (slab->us_freecount+1 == zone->uz_ipers) {
1670 LIST_REMOVE(slab, us_link);
1671 LIST_INSERT_HEAD(&zone->uz_free_slab, slab, us_link);
1672 } else if (slab->us_freecount == 0) {
1673 LIST_REMOVE(slab, us_link);
1674 LIST_INSERT_HEAD(&zone->uz_part_slab, slab, us_link);
1675 }
1676
1677 /* Slab management stuff */
1678 freei = ((unsigned long)item - (unsigned long)slab->us_data)
1679 / zone->uz_rsize;
1680#ifdef INVARIANTS
1681 if (((freei * zone->uz_rsize) + slab->us_data) != item)
1682 panic("zone: %s(%p) slab %p freed address %p unaligned.\n",
1683 zone->uz_name, zone, slab, item);
1684 if (freei >= zone->uz_ipers)
1685 panic("zone: %s(%p) slab %p freelist %i out of range 0-%d\n",
1686 zone->uz_name, zone, slab, freei, zone->uz_ipers-1);
1687
1688 if (slab->us_freelist[freei] != 255) {
1689 printf("Slab at %p, freei %d = %d.\n",
1690 slab, freei, slab->us_freelist[freei]);
1691 panic("Duplicate free of item %p from zone %p(%s)\n",
1692 item, zone, zone->uz_name);
1693 }
1694#endif
1695 slab->us_freelist[freei] = slab->us_firstfree;
1696 slab->us_firstfree = freei;
1697 slab->us_freecount++;
1698
1699 /* Zone statistics */
1700 zone->uz_free++;
1701
1702 ZONE_UNLOCK(zone);
1703
1704 if (!skip && zone->uz_dtor)
1705 zone->uz_dtor(item, zone->uz_size, udata);
1706}
1707
1708/* See uma.h */
1709void
1710uma_zone_set_max(uma_zone_t zone, int nitems)
1711{
1712 ZONE_LOCK(zone);
1713 if (zone->uz_ppera > 1)
1714 zone->uz_maxpages = nitems / zone->uz_ppera;
1715 else
1716 zone->uz_maxpages = nitems / zone->uz_ipers;
1717 ZONE_UNLOCK(zone);
1718}
1719
1720/* See uma.h */
1721void
1722uma_zone_set_freef(uma_zone_t zone, uma_free freef)
1723{
1724 ZONE_LOCK(zone);
1725
1726 zone->uz_freef = freef;
1727
1728 ZONE_UNLOCK(zone);
1729}
1730
1731/* See uma.h */
1732void
1733uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf)
1734{
1735 ZONE_LOCK(zone);
1736
1737 zone->uz_flags |= UMA_ZFLAG_PRIVALLOC;
1738 zone->uz_allocf = allocf;
1739
1740 ZONE_UNLOCK(zone);
1741}
1742
1743/* See uma.h */
1744int
1745uma_zone_set_obj(uma_zone_t zone, struct vm_object *obj, int count)
1746{
1747 int pages;
1748 vm_offset_t kva;
1749
1750 mtx_lock(&Giant);
1751
1752 pages = count / zone->uz_ipers;
1753
1754 if (pages * zone->uz_ipers < count)
1755 pages++;
1756
1757 kva = kmem_alloc_pageable(kernel_map, pages * UMA_SLAB_SIZE);
1758
1759 if (kva == 0) {
1760 mtx_unlock(&Giant);
1761 return (0);
1762 }
1763
1764
1765 if (obj == NULL)
1766 obj = vm_object_allocate(OBJT_DEFAULT,
1767 zone->uz_maxpages);
1768 else
1769 _vm_object_allocate(OBJT_DEFAULT,
1770 zone->uz_maxpages, obj);
1771
1772 ZONE_LOCK(zone);
1773 zone->uz_kva = kva;
1774 zone->uz_obj = obj;
1775 zone->uz_maxpages = pages;
1776
1777 zone->uz_allocf = obj_alloc;
1778 zone->uz_flags |= UMA_ZFLAG_NOFREE | UMA_ZFLAG_PRIVALLOC;
1779
1780 ZONE_UNLOCK(zone);
1781 mtx_unlock(&Giant);
1782
1783 return (1);
1784}
1785
1786/* See uma.h */
1787void
1788uma_prealloc(uma_zone_t zone, int items)
1789{
1790 int slabs;
1791 uma_slab_t slab;
1792
1793 ZONE_LOCK(zone);
1794 slabs = items / zone->uz_ipers;
1795 if (slabs * zone->uz_ipers < items)
1796 slabs++;
1797
1798 while (slabs > 0) {
1799 slab = slab_zalloc(zone, M_WAITOK);
1800 LIST_INSERT_HEAD(&zone->uz_free_slab, slab, us_link);
1801 slabs--;
1802 }
1803 ZONE_UNLOCK(zone);
1804}
1805
1806/* See uma.h */
1807void
1808uma_reclaim(void)
1809{
1810 /*
1811 * You might think that the delay below would improve performance since
1812 * the allocator will give away memory that it may ask for immediately.
1813 * Really, it makes things worse, since cpu cycles are so much cheaper
1814 * than disk activity.
1815 */
1816#if 0
1817 static struct timeval tv = {0};
1818 struct timeval now;
1819 getmicrouptime(&now);
1820 if (now.tv_sec > tv.tv_sec + 30)
1821 tv = now;
1822 else
1823 return;
1824#endif
1825#ifdef UMA_DEBUG
1826 printf("UMA: vm asked us to release pages!\n");
1827#endif
1828 zone_foreach(zone_drain);
1829
1830 /*
1831 * Some slabs may have been freed but this zone will be visited early
1832 * we visit again so that we can free pages that are empty once other
1833 * zones are drained. We have to do the same for buckets.
1834 */
1835 zone_drain(slabzone);
1836 zone_drain(bucketzone);
1837}
1838
1839void *
1840uma_large_malloc(int size, int wait)
1841{
1842 void *mem;
1843 uma_slab_t slab;
1844 u_int8_t flags;
1845
1846 slab = uma_zalloc_internal(slabzone, NULL, wait, NULL);
1847 if (slab == NULL)
1848 return (NULL);
1849
1850 mem = page_alloc(NULL, size, &flags, wait);
1851 if (mem) {
1852 slab->us_data = mem;
1853 slab->us_flags = flags | UMA_SLAB_MALLOC;
1854 slab->us_size = size;
1855 UMA_HASH_INSERT(mallochash, slab, mem);
1856 } else {
1857 uma_zfree_internal(slabzone, slab, NULL, 0);
1858 }
1859
1860
1861 return (mem);
1862}
1863
1864void
1865uma_large_free(uma_slab_t slab)
1866{
1867 UMA_HASH_REMOVE(mallochash, slab, slab->us_data);
1868 page_free(slab->us_data, slab->us_size, slab->us_flags);
1869 uma_zfree_internal(slabzone, slab, NULL, 0);
1870}
1871
1872void
1873uma_print_stats(void)
1874{
1875 zone_foreach(uma_print_zone);
1876}
1877
1878void
1879uma_print_zone(uma_zone_t zone)
1880{
1881 printf("%s(%p) size %d(%d) flags %d ipers %d ppera %d out %d free %d\n",
1882 zone->uz_name, zone, zone->uz_size, zone->uz_rsize, zone->uz_flags,
1883 zone->uz_ipers, zone->uz_ppera,
1884 (zone->uz_ipers * zone->uz_pages) - zone->uz_free, zone->uz_free);
1885}
1886
1887/*
1888 * Sysctl handler for vm.zone
1889 *
1890 * stolen from vm_zone.c
1891 */
1892static int
1893sysctl_vm_zone(SYSCTL_HANDLER_ARGS)
1894{
1895 int error, len, cnt;
1896 const int linesize = 128; /* conservative */
1897 int totalfree;
1898 char *tmpbuf, *offset;
1899 uma_zone_t z;
1900 char *p;
1901
1902 cnt = 0;
1903 LIST_FOREACH(z, &uma_zones, uz_link)
1904 cnt++;
1905 MALLOC(tmpbuf, char *, (cnt == 0 ? 1 : cnt) * linesize,
1906 M_TEMP, M_WAITOK);
1907 len = snprintf(tmpbuf, linesize,
1908 "\nITEM SIZE LIMIT USED FREE REQUESTS\n\n");
1909 if (cnt == 0)
1910 tmpbuf[len - 1] = '\0';
1911 error = SYSCTL_OUT(req, tmpbuf, cnt == 0 ? len-1 : len);
1912 if (error || cnt == 0)
1913 goto out;
1914 offset = tmpbuf;
1915 mtx_lock(&uma_mtx);
1916 LIST_FOREACH(z, &uma_zones, uz_link) {
1917 if (cnt == 0) /* list may have changed size */
1918 break;
1919 ZONE_LOCK(z);
1920 totalfree = z->uz_free + z->uz_cachefree;
1921 len = snprintf(offset, linesize,
1922 "%-12.12s %6.6u, %8.8u, %6.6u, %6.6u, %8.8llu\n",
1923 z->uz_name, z->uz_size,
1924 z->uz_maxpages * z->uz_ipers,
1925 (z->uz_ipers * (z->uz_pages / z->uz_ppera)) - totalfree,
1926 totalfree,
1927 (unsigned long long)z->uz_allocs);
1928 ZONE_UNLOCK(z);
1929 for (p = offset + 12; p > offset && *p == ' '; --p)
1930 /* nothing */ ;
1931 p[1] = ':';
1932 cnt--;
1933 offset += len;
1934 }
1935 mtx_unlock(&uma_mtx);
1936 *offset++ = '\0';
1937 error = SYSCTL_OUT(req, tmpbuf, offset - tmpbuf);
1938out:
1939 FREE(tmpbuf, M_TEMP);
1940 return (error);
1941}
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