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759 palkovsky 1
/*
2
 * Copyright (C) 2006 Ondrej Palkovsky
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
 *
9
 * - Redistributions of source code must retain the above copyright
10
 *   notice, this list of conditions and the following disclaimer.
11
 * - 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
 * - The name of the author may not be used to endorse or promote products
15
 *   derived from this software without specific prior written permission.
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
 
769 palkovsky 29
/*
785 jermar 30
 * The SLAB allocator is closely modelled after OpenSolaris SLAB allocator
769 palkovsky 31
 * http://www.usenix.org/events/usenix01/full_papers/bonwick/bonwick_html/
32
 *
33
 * with the following exceptions:
34
 *   - empty SLABS are deallocated immediately 
35
 *     (in Linux they are kept in linked list, in Solaris ???)
36
 *   - empty magazines are deallocated when not needed
37
 *     (in Solaris they are held in linked list in slab cache)
38
 *
39
 *   Following features are not currently supported but would be easy to do:
40
 *   - cache coloring
41
 *   - dynamic magazine growing (different magazine sizes are already
1144 jermar 42
 *     supported, but we would need to adjust allocation strategy)
769 palkovsky 43
 *
44
 * The SLAB allocator supports per-CPU caches ('magazines') to facilitate
45
 * good SMP scaling. 
46
 *
47
 * When a new object is being allocated, it is first checked, if it is 
48
 * available in CPU-bound magazine. If it is not found there, it is
49
 * allocated from CPU-shared SLAB - if partial full is found, it is used,
50
 * otherwise a new one is allocated. 
51
 *
52
 * When an object is being deallocated, it is put to CPU-bound magazine.
53
 * If there is no such magazine, new one is allocated (if it fails, 
54
 * the object is deallocated into SLAB). If the magazine is full, it is
55
 * put into cpu-shared list of magazines and new one is allocated.
56
 *
57
 * The CPU-bound magazine is actually a pair of magazine to avoid
58
 * thrashing when somebody is allocating/deallocating 1 item at the magazine
59
 * size boundary. LIFO order is enforced, which should avoid fragmentation
60
 * as much as possible. 
61
 *  
62
 * Every cache contains list of full slabs and list of partialy full slabs.
63
 * Empty SLABS are immediately freed (thrashing will be avoided because
64
 * of magazines). 
65
 *
66
 * The SLAB information structure is kept inside the data area, if possible.
67
 * The cache can be marked that it should not use magazines. This is used
68
 * only for SLAB related caches to avoid deadlocks and infinite recursion
69
 * (the SLAB allocator uses itself for allocating all it's control structures).
70
 *
71
 * The SLAB allocator allocates lot of space and does not free it. When
72
 * frame allocator fails to allocate the frame, it calls slab_reclaim().
73
 * It tries 'light reclaim' first, then brutal reclaim. The light reclaim
74
 * releases slabs from cpu-shared magazine-list, until at least 1 slab 
75
 * is deallocated in each cache (this algorithm should probably change).
76
 * The brutal reclaim removes all cached objects, even from CPU-bound
77
 * magazines.
78
 *
775 palkovsky 79
 * TODO: For better CPU-scaling the magazine allocation strategy should
80
 * be extended. Currently, if the cache does not have magazine, it asks
81
 * for non-cpu cached magazine cache to provide one. It might be feasible
82
 * to add cpu-cached magazine cache (which would allocate it's magazines
83
 * from non-cpu-cached mag. cache). This would provide a nice per-cpu
84
 * buffer. The other possibility is to use the per-cache 
85
 * 'empty-magazine-list', which decreases competing for 1 per-system
86
 * magazine cache.
87
 *
776 palkovsky 88
 * - it might be good to add granularity of locks even to slab level,
89
 *   we could then try_spinlock over all partial slabs and thus improve
90
 *   scalability even on slab level
769 palkovsky 91
 */
92
 
93
 
759 palkovsky 94
#include <synch/spinlock.h>
95
#include <mm/slab.h>
788 jermar 96
#include <adt/list.h>
759 palkovsky 97
#include <memstr.h>
98
#include <align.h>
762 palkovsky 99
#include <mm/frame.h>
759 palkovsky 100
#include <config.h>
101
#include <print.h>
102
#include <arch.h>
103
#include <panic.h>
762 palkovsky 104
#include <debug.h>
771 palkovsky 105
#include <bitops.h>
759 palkovsky 106
 
107
SPINLOCK_INITIALIZE(slab_cache_lock);
769 palkovsky 108
static LIST_INITIALIZE(slab_cache_list);
759 palkovsky 109
 
769 palkovsky 110
/** Magazine cache */
111
static slab_cache_t mag_cache;
112
/** Cache for cache descriptors */
113
static slab_cache_t slab_cache_cache;
114
/** Cache for external slab descriptors
115
 * This time we want per-cpu cache, so do not make it static
116
 * - using SLAB for internal SLAB structures will not deadlock,
117
 *   as all slab structures are 'small' - control structures of
118
 *   their caches do not require further allocation
119
 */
120
static slab_cache_t *slab_extern_cache;
771 palkovsky 121
/** Caches for malloc */
122
static slab_cache_t *malloc_caches[SLAB_MAX_MALLOC_W-SLAB_MIN_MALLOC_W+1];
123
char *malloc_names[] =  {
791 palkovsky 124
	"malloc-16","malloc-32","malloc-64","malloc-128",
771 palkovsky 125
	"malloc-256","malloc-512","malloc-1K","malloc-2K",
126
	"malloc-4K","malloc-8K","malloc-16K","malloc-32K",
127
	"malloc-64K","malloc-128K"
128
};
762 palkovsky 129
 
769 palkovsky 130
/** Slab descriptor */
762 palkovsky 131
typedef struct {
132
	slab_cache_t *cache; /**< Pointer to parent cache */
133
	link_t link;       /* List of full/partial slabs */
134
	void *start;       /**< Start address of first available item */
135
	count_t available; /**< Count of available items in this slab */
136
	index_t nextavail; /**< The index of next available item */
137
}slab_t;
138
 
791 palkovsky 139
#ifdef CONFIG_DEBUG
140
static int _slab_initialized = 0;
141
#endif
142
 
759 palkovsky 143
/**************************************/
762 palkovsky 144
/* SLAB allocation functions          */
759 palkovsky 145
 
762 palkovsky 146
/**
147
 * Allocate frames for slab space and initialize
148
 *
149
 */
150
static slab_t * slab_space_alloc(slab_cache_t *cache, int flags)
151
{
152
	void *data;
153
	slab_t *slab;
154
	size_t fsize;
155
	int i;
156
	int status;
814 palkovsky 157
	pfn_t pfn;
158
	int zone=0;
159
 
160
	pfn = frame_alloc_rc_zone(cache->order, FRAME_KA | flags, &status, &zone);
161
	data = (void *) PA2KA(PFN2ADDR(pfn));
764 palkovsky 162
	if (status != FRAME_OK) {
762 palkovsky 163
		return NULL;
764 palkovsky 164
	}
768 palkovsky 165
	if (! (cache->flags & SLAB_CACHE_SLINSIDE)) {
769 palkovsky 166
		slab = slab_alloc(slab_extern_cache, flags);
762 palkovsky 167
		if (!slab) {
814 palkovsky 168
			frame_free(ADDR2PFN(KA2PA(data)));
762 palkovsky 169
			return NULL;
170
		}
171
	} else {
172
		fsize = (PAGE_SIZE << cache->order);
173
		slab = data + fsize - sizeof(*slab);
174
	}
764 palkovsky 175
 
762 palkovsky 176
	/* Fill in slab structures */
814 palkovsky 177
	for (i=0; i < (1 << cache->order); i++)
178
		frame_set_parent(pfn+i, slab, zone);
762 palkovsky 179
 
180
	slab->start = data;
181
	slab->available = cache->objects;
182
	slab->nextavail = 0;
767 palkovsky 183
	slab->cache = cache;
762 palkovsky 184
 
185
	for (i=0; i<cache->objects;i++)
186
		*((int *) (slab->start + i*cache->size)) = i+1;
764 palkovsky 187
 
188
	atomic_inc(&cache->allocated_slabs);
762 palkovsky 189
	return slab;
190
}
191
 
759 palkovsky 192
/**
766 palkovsky 193
 * Deallocate space associated with SLAB
762 palkovsky 194
 *
195
 * @return number of freed frames
196
 */
197
static count_t slab_space_free(slab_cache_t *cache, slab_t *slab)
198
{
814 palkovsky 199
	frame_free(ADDR2PFN(KA2PA(slab->start)));
768 palkovsky 200
	if (! (cache->flags & SLAB_CACHE_SLINSIDE))
769 palkovsky 201
		slab_free(slab_extern_cache, slab);
764 palkovsky 202
 
203
	atomic_dec(&cache->allocated_slabs);
204
 
762 palkovsky 205
	return 1 << cache->order;
206
}
207
 
208
/** Map object to slab structure */
209
static slab_t * obj2slab(void *obj)
210
{
814 palkovsky 211
	return (slab_t *)frame_get_parent(ADDR2PFN(KA2PA(obj)), 0);
762 palkovsky 212
}
213
 
214
/**************************************/
215
/* SLAB functions */
216
 
217
 
218
/**
759 palkovsky 219
 * Return object to slab and call a destructor
220
 *
762 palkovsky 221
 * @param slab If the caller knows directly slab of the object, otherwise NULL
222
 *
759 palkovsky 223
 * @return Number of freed pages
224
 */
762 palkovsky 225
static count_t slab_obj_destroy(slab_cache_t *cache, void *obj,
226
				slab_t *slab)
759 palkovsky 227
{
787 palkovsky 228
	int freed = 0;
229
 
762 palkovsky 230
	if (!slab)
231
		slab = obj2slab(obj);
232
 
767 palkovsky 233
	ASSERT(slab->cache == cache);
234
 
787 palkovsky 235
	if (cache->destructor)
236
		freed = cache->destructor(obj);
237
 
776 palkovsky 238
	spinlock_lock(&cache->slablock);
789 palkovsky 239
	ASSERT(slab->available < cache->objects);
776 palkovsky 240
 
762 palkovsky 241
	*((int *)obj) = slab->nextavail;
242
	slab->nextavail = (obj - slab->start)/cache->size;
243
	slab->available++;
244
 
245
	/* Move it to correct list */
246
	if (slab->available == cache->objects) {
247
		/* Free associated memory */
248
		list_remove(&slab->link);
782 palkovsky 249
		spinlock_unlock(&cache->slablock);
250
 
787 palkovsky 251
		return freed + slab_space_free(cache, slab);
782 palkovsky 252
 
780 palkovsky 253
	} else if (slab->available == 1) {
254
		/* It was in full, move to partial */
255
		list_remove(&slab->link);
256
		list_prepend(&slab->link, &cache->partial_slabs);
762 palkovsky 257
	}
783 palkovsky 258
	spinlock_unlock(&cache->slablock);
787 palkovsky 259
	return freed;
759 palkovsky 260
}
261
 
262
/**
263
 * Take new object from slab or create new if needed
264
 *
265
 * @return Object address or null
266
 */
267
static void * slab_obj_create(slab_cache_t *cache, int flags)
268
{
762 palkovsky 269
	slab_t *slab;
270
	void *obj;
271
 
776 palkovsky 272
	spinlock_lock(&cache->slablock);
273
 
762 palkovsky 274
	if (list_empty(&cache->partial_slabs)) {
275
		/* Allow recursion and reclaiming
276
		 * - this should work, as the SLAB control structures
277
		 *   are small and do not need to allocte with anything
278
		 *   other ten frame_alloc when they are allocating,
279
		 *   that's why we should get recursion at most 1-level deep
280
		 */
776 palkovsky 281
		spinlock_unlock(&cache->slablock);
762 palkovsky 282
		slab = slab_space_alloc(cache, flags);
780 palkovsky 283
		if (!slab)
284
			return NULL;
776 palkovsky 285
		spinlock_lock(&cache->slablock);
762 palkovsky 286
	} else {
287
		slab = list_get_instance(cache->partial_slabs.next,
288
					 slab_t,
289
					 link);
290
		list_remove(&slab->link);
291
	}
292
	obj = slab->start + slab->nextavail * cache->size;
293
	slab->nextavail = *((int *)obj);
294
	slab->available--;
787 palkovsky 295
 
762 palkovsky 296
	if (! slab->available)
764 palkovsky 297
		list_prepend(&slab->link, &cache->full_slabs);
762 palkovsky 298
	else
764 palkovsky 299
		list_prepend(&slab->link, &cache->partial_slabs);
776 palkovsky 300
 
301
	spinlock_unlock(&cache->slablock);
787 palkovsky 302
 
303
	if (cache->constructor && cache->constructor(obj, flags)) {
304
		/* Bad, bad, construction failed */
305
		slab_obj_destroy(cache, obj, slab);
306
		return NULL;
307
	}
762 palkovsky 308
	return obj;
759 palkovsky 309
}
310
 
311
/**************************************/
312
/* CPU-Cache slab functions */
313
 
314
/**
781 palkovsky 315
 * Finds a full magazine in cache, takes it from list
316
 * and returns it 
317
 *
318
 * @param first If true, return first, else last mag
319
 */
320
static slab_magazine_t * get_mag_from_cache(slab_cache_t *cache,
321
					    int first)
322
{
323
	slab_magazine_t *mag = NULL;
324
	link_t *cur;
325
 
326
	spinlock_lock(&cache->maglock);
327
	if (!list_empty(&cache->magazines)) {
328
		if (first)
329
			cur = cache->magazines.next;
330
		else
331
			cur = cache->magazines.prev;
332
		mag = list_get_instance(cur, slab_magazine_t, link);
333
		list_remove(&mag->link);
334
		atomic_dec(&cache->magazine_counter);
335
	}
336
	spinlock_unlock(&cache->maglock);
337
	return mag;
338
}
339
 
340
/** Prepend magazine to magazine list in cache */
341
static void put_mag_to_cache(slab_cache_t *cache, slab_magazine_t *mag)
342
{
343
	spinlock_lock(&cache->maglock);
344
 
345
	list_prepend(&mag->link, &cache->magazines);
346
	atomic_inc(&cache->magazine_counter);
347
 
348
	spinlock_unlock(&cache->maglock);
349
}
350
 
351
/**
759 palkovsky 352
 * Free all objects in magazine and free memory associated with magazine
353
 *
354
 * @return Number of freed pages
355
 */
356
static count_t magazine_destroy(slab_cache_t *cache, 
357
				slab_magazine_t *mag)
358
{
359
	int i;
360
	count_t frames = 0;
361
 
767 palkovsky 362
	for (i=0;i < mag->busy; i++) {
762 palkovsky 363
		frames += slab_obj_destroy(cache, mag->objs[i], NULL);
767 palkovsky 364
		atomic_dec(&cache->cached_objs);
365
	}
759 palkovsky 366
 
367
	slab_free(&mag_cache, mag);
368
 
369
	return frames;
370
}
371
 
372
/**
769 palkovsky 373
 * Find full magazine, set it as current and return it
374
 *
375
 * Assume cpu_magazine lock is held
376
 */
377
static slab_magazine_t * get_full_current_mag(slab_cache_t *cache)
378
{
379
	slab_magazine_t *cmag, *lastmag, *newmag;
380
 
381
	cmag = cache->mag_cache[CPU->id].current;
382
	lastmag = cache->mag_cache[CPU->id].last;
383
	if (cmag) { /* First try local CPU magazines */
384
		if (cmag->busy)
385
			return cmag;
386
 
387
		if (lastmag && lastmag->busy) {
388
			cache->mag_cache[CPU->id].current = lastmag;
389
			cache->mag_cache[CPU->id].last = cmag;
390
			return lastmag;
391
		}
392
	}
393
	/* Local magazines are empty, import one from magazine list */
781 palkovsky 394
	newmag = get_mag_from_cache(cache, 1);
395
	if (!newmag)
769 palkovsky 396
		return NULL;
397
 
398
	if (lastmag)
781 palkovsky 399
		magazine_destroy(cache, lastmag);
400
 
769 palkovsky 401
	cache->mag_cache[CPU->id].last = cmag;
402
	cache->mag_cache[CPU->id].current = newmag;
403
	return newmag;
404
}
405
 
406
/**
759 palkovsky 407
 * Try to find object in CPU-cache magazines
408
 *
409
 * @return Pointer to object or NULL if not available
410
 */
411
static void * magazine_obj_get(slab_cache_t *cache)
412
{
413
	slab_magazine_t *mag;
767 palkovsky 414
	void *obj;
759 palkovsky 415
 
772 palkovsky 416
	if (!CPU)
417
		return NULL;
418
 
759 palkovsky 419
	spinlock_lock(&cache->mag_cache[CPU->id].lock);
420
 
769 palkovsky 421
	mag = get_full_current_mag(cache);
422
	if (!mag) {
423
		spinlock_unlock(&cache->mag_cache[CPU->id].lock);
424
		return NULL;
759 palkovsky 425
	}
767 palkovsky 426
	obj = mag->objs[--mag->busy];
759 palkovsky 427
	spinlock_unlock(&cache->mag_cache[CPU->id].lock);
767 palkovsky 428
	atomic_dec(&cache->cached_objs);
429
 
430
	return obj;
759 palkovsky 431
}
432
 
433
/**
768 palkovsky 434
 * Assure that the current magazine is empty, return pointer to it, or NULL if 
769 palkovsky 435
 * no empty magazine is available and cannot be allocated
759 palkovsky 436
 *
773 palkovsky 437
 * Assume mag_cache[CPU->id].lock is held
438
 *
759 palkovsky 439
 * We have 2 magazines bound to processor. 
440
 * First try the current. 
441
 *  If full, try the last.
442
 *   If full, put to magazines list.
443
 *   allocate new, exchange last & current
444
 *
768 palkovsky 445
 */
446
static slab_magazine_t * make_empty_current_mag(slab_cache_t *cache)
447
{
448
	slab_magazine_t *cmag,*lastmag,*newmag;
449
 
450
	cmag = cache->mag_cache[CPU->id].current;
451
	lastmag = cache->mag_cache[CPU->id].last;
452
 
453
	if (cmag) {
454
		if (cmag->busy < cmag->size)
455
			return cmag;
456
		if (lastmag && lastmag->busy < lastmag->size) {
457
			cache->mag_cache[CPU->id].last = cmag;
458
			cache->mag_cache[CPU->id].current = lastmag;
459
			return lastmag;
460
		}
461
	}
462
	/* current | last are full | nonexistent, allocate new */
463
	/* We do not want to sleep just because of caching */
464
	/* Especially we do not want reclaiming to start, as 
465
	 * this would deadlock */
466
	newmag = slab_alloc(&mag_cache, FRAME_ATOMIC | FRAME_NO_RECLAIM);
467
	if (!newmag)
468
		return NULL;
469
	newmag->size = SLAB_MAG_SIZE;
470
	newmag->busy = 0;
471
 
472
	/* Flush last to magazine list */
781 palkovsky 473
	if (lastmag)
474
		put_mag_to_cache(cache, lastmag);
475
 
768 palkovsky 476
	/* Move current as last, save new as current */
477
	cache->mag_cache[CPU->id].last = cmag;	
478
	cache->mag_cache[CPU->id].current = newmag;	
479
 
480
	return newmag;
481
}
482
 
483
/**
484
 * Put object into CPU-cache magazine
485
 *
759 palkovsky 486
 * @return 0 - success, -1 - could not get memory
487
 */
488
static int magazine_obj_put(slab_cache_t *cache, void *obj)
489
{
490
	slab_magazine_t *mag;
491
 
772 palkovsky 492
	if (!CPU)
493
		return -1;
494
 
759 palkovsky 495
	spinlock_lock(&cache->mag_cache[CPU->id].lock);
768 palkovsky 496
 
497
	mag = make_empty_current_mag(cache);
769 palkovsky 498
	if (!mag) {
499
		spinlock_unlock(&cache->mag_cache[CPU->id].lock);
500
		return -1;
501
	}
759 palkovsky 502
 
503
	mag->objs[mag->busy++] = obj;
504
 
505
	spinlock_unlock(&cache->mag_cache[CPU->id].lock);
767 palkovsky 506
	atomic_inc(&cache->cached_objs);
759 palkovsky 507
	return 0;
508
}
509
 
510
 
511
/**************************************/
762 palkovsky 512
/* SLAB CACHE functions */
759 palkovsky 513
 
762 palkovsky 514
/** Return number of objects that fit in certain cache size */
515
static int comp_objects(slab_cache_t *cache)
516
{
517
	if (cache->flags & SLAB_CACHE_SLINSIDE)
518
		return ((PAGE_SIZE << cache->order) - sizeof(slab_t)) / cache->size;
519
	else 
520
		return (PAGE_SIZE << cache->order) / cache->size;
521
}
522
 
523
/** Return wasted space in slab */
524
static int badness(slab_cache_t *cache)
525
{
526
	int objects;
527
	int ssize;
528
 
529
	objects = comp_objects(cache);
530
	ssize = PAGE_SIZE << cache->order;
531
	if (cache->flags & SLAB_CACHE_SLINSIDE)
532
		ssize -= sizeof(slab_t);
533
	return ssize - objects*cache->size;
534
}
535
 
789 palkovsky 536
/**
537
 * Initialize mag_cache structure in slab cache
538
 */
539
static void make_magcache(slab_cache_t *cache)
540
{
541
	int i;
791 palkovsky 542
 
543
	ASSERT(_slab_initialized >= 2);
789 palkovsky 544
 
822 palkovsky 545
	cache->mag_cache = malloc(sizeof(slab_mag_cache_t)*config.cpu_count,0);
789 palkovsky 546
	for (i=0; i < config.cpu_count; i++) {
547
		memsetb((__address)&cache->mag_cache[i],
548
			sizeof(cache->mag_cache[i]), 0);
549
		spinlock_initialize(&cache->mag_cache[i].lock, 
550
				    "slab_maglock_cpu");
551
	}
552
}
553
 
759 palkovsky 554
/** Initialize allocated memory as a slab cache */
555
static void
556
_slab_cache_create(slab_cache_t *cache,
557
		   char *name,
558
		   size_t size,
559
		   size_t align,
560
		   int (*constructor)(void *obj, int kmflag),
787 palkovsky 561
		   int (*destructor)(void *obj),
759 palkovsky 562
		   int flags)
563
{
771 palkovsky 564
	int pages;
783 palkovsky 565
	ipl_t ipl;
759 palkovsky 566
 
567
	memsetb((__address)cache, sizeof(*cache), 0);
568
	cache->name = name;
569
 
766 palkovsky 570
	if (align < sizeof(__native))
571
		align = sizeof(__native);
572
	size = ALIGN_UP(size, align);
573
 
762 palkovsky 574
	cache->size = size;
759 palkovsky 575
 
576
	cache->constructor = constructor;
577
	cache->destructor = destructor;
578
	cache->flags = flags;
579
 
580
	list_initialize(&cache->full_slabs);
581
	list_initialize(&cache->partial_slabs);
582
	list_initialize(&cache->magazines);
776 palkovsky 583
	spinlock_initialize(&cache->slablock, "slab_lock");
584
	spinlock_initialize(&cache->maglock, "slab_maglock");
789 palkovsky 585
	if (! (cache->flags & SLAB_CACHE_NOMAGAZINE))
586
		make_magcache(cache);
759 palkovsky 587
 
588
	/* Compute slab sizes, object counts in slabs etc. */
589
	if (cache->size < SLAB_INSIDE_SIZE)
590
		cache->flags |= SLAB_CACHE_SLINSIDE;
591
 
762 palkovsky 592
	/* Minimum slab order */
771 palkovsky 593
	pages = ((cache->size-1) >> PAGE_WIDTH) + 1;
594
	cache->order = fnzb(pages);
766 palkovsky 595
 
762 palkovsky 596
	while (badness(cache) > SLAB_MAX_BADNESS(cache)) {
597
		cache->order += 1;
598
	}
599
	cache->objects = comp_objects(cache);
766 palkovsky 600
	/* If info fits in, put it inside */
601
	if (badness(cache) > sizeof(slab_t))
602
		cache->flags |= SLAB_CACHE_SLINSIDE;
762 palkovsky 603
 
783 palkovsky 604
	/* Add cache to cache list */
605
	ipl = interrupts_disable();
759 palkovsky 606
	spinlock_lock(&slab_cache_lock);
607
 
608
	list_append(&cache->link, &slab_cache_list);
609
 
610
	spinlock_unlock(&slab_cache_lock);
783 palkovsky 611
	interrupts_restore(ipl);
759 palkovsky 612
}
613
 
614
/** Create slab cache  */
615
slab_cache_t * slab_cache_create(char *name,
616
				 size_t size,
617
				 size_t align,
618
				 int (*constructor)(void *obj, int kmflag),
787 palkovsky 619
				 int (*destructor)(void *obj),
759 palkovsky 620
				 int flags)
621
{
622
	slab_cache_t *cache;
623
 
769 palkovsky 624
	cache = slab_alloc(&slab_cache_cache, 0);
759 palkovsky 625
	_slab_cache_create(cache, name, size, align, constructor, destructor,
626
			   flags);
627
	return cache;
628
}
629
 
630
/** 
631
 * Reclaim space occupied by objects that are already free
632
 *
633
 * @param flags If contains SLAB_RECLAIM_ALL, do aggressive freeing
634
 * @return Number of freed pages
635
 */
636
static count_t _slab_reclaim(slab_cache_t *cache, int flags)
637
{
638
	int i;
639
	slab_magazine_t *mag;
640
	count_t frames = 0;
781 palkovsky 641
	int magcount;
759 palkovsky 642
 
643
	if (cache->flags & SLAB_CACHE_NOMAGAZINE)
644
		return 0; /* Nothing to do */
781 palkovsky 645
 
646
	/* We count up to original magazine count to avoid
647
	 * endless loop 
648
	 */
649
	magcount = atomic_get(&cache->magazine_counter);
650
	while (magcount-- && (mag=get_mag_from_cache(cache,0))) {
651
		frames += magazine_destroy(cache,mag);
652
		if (!(flags & SLAB_RECLAIM_ALL) && frames)
653
			break;
769 palkovsky 654
	}
759 palkovsky 655
 
656
	if (flags & SLAB_RECLAIM_ALL) {
781 palkovsky 657
		/* Free cpu-bound magazines */
759 palkovsky 658
		/* Destroy CPU magazines */
659
		for (i=0; i<config.cpu_count; i++) {
781 palkovsky 660
			spinlock_lock(&cache->mag_cache[i].lock);
661
 
759 palkovsky 662
			mag = cache->mag_cache[i].current;
663
			if (mag)
664
				frames += magazine_destroy(cache, mag);
665
			cache->mag_cache[i].current = NULL;
666
 
667
			mag = cache->mag_cache[i].last;
668
			if (mag)
669
				frames += magazine_destroy(cache, mag);
670
			cache->mag_cache[i].last = NULL;
781 palkovsky 671
 
672
			spinlock_unlock(&cache->mag_cache[i].lock);
759 palkovsky 673
		}
674
	}
767 palkovsky 675
 
759 palkovsky 676
	return frames;
677
}
678
 
679
/** Check that there are no slabs and remove cache from system  */
680
void slab_cache_destroy(slab_cache_t *cache)
681
{
781 palkovsky 682
	ipl_t ipl;
683
 
684
	/* First remove cache from link, so that we don't need
685
	 * to disable interrupts later
686
	 */
687
 
688
	ipl = interrupts_disable();
689
	spinlock_lock(&slab_cache_lock);
690
 
691
	list_remove(&cache->link);
692
 
693
	spinlock_unlock(&slab_cache_lock);
694
	interrupts_restore(ipl);
695
 
759 palkovsky 696
	/* Do not lock anything, we assume the software is correct and
697
	 * does not touch the cache when it decides to destroy it */
698
 
699
	/* Destroy all magazines */
700
	_slab_reclaim(cache, SLAB_RECLAIM_ALL);
701
 
702
	/* All slabs must be empty */
703
	if (!list_empty(&cache->full_slabs) \
704
	    || !list_empty(&cache->partial_slabs))
705
		panic("Destroying cache that is not empty.");
706
 
789 palkovsky 707
	if (!(cache->flags & SLAB_CACHE_NOMAGAZINE))
822 palkovsky 708
		free(cache->mag_cache);
769 palkovsky 709
	slab_free(&slab_cache_cache, cache);
759 palkovsky 710
}
711
 
712
/** Allocate new object from cache - if no flags given, always returns 
713
    memory */
714
void * slab_alloc(slab_cache_t *cache, int flags)
715
{
716
	ipl_t ipl;
717
	void *result = NULL;
773 palkovsky 718
 
759 palkovsky 719
	/* Disable interrupts to avoid deadlocks with interrupt handlers */
720
	ipl = interrupts_disable();
771 palkovsky 721
 
814 palkovsky 722
	if (!(cache->flags & SLAB_CACHE_NOMAGAZINE)) {
759 palkovsky 723
		result = magazine_obj_get(cache);
814 palkovsky 724
	}
776 palkovsky 725
	if (!result)
759 palkovsky 726
		result = slab_obj_create(cache, flags);
727
 
769 palkovsky 728
	interrupts_restore(ipl);
729
 
764 palkovsky 730
	if (result)
731
		atomic_inc(&cache->allocated_objs);
732
 
759 palkovsky 733
	return result;
734
}
735
 
771 palkovsky 736
/** Return object to cache, use slab if known  */
737
static void _slab_free(slab_cache_t *cache, void *obj, slab_t *slab)
759 palkovsky 738
{
739
	ipl_t ipl;
740
 
741
	ipl = interrupts_disable();
742
 
762 palkovsky 743
	if ((cache->flags & SLAB_CACHE_NOMAGAZINE) \
744
	    || magazine_obj_put(cache, obj)) {
776 palkovsky 745
 
771 palkovsky 746
		slab_obj_destroy(cache, obj, slab);
776 palkovsky 747
 
759 palkovsky 748
	}
769 palkovsky 749
	interrupts_restore(ipl);
764 palkovsky 750
	atomic_dec(&cache->allocated_objs);
759 palkovsky 751
}
752
 
771 palkovsky 753
/** Return slab object to cache */
754
void slab_free(slab_cache_t *cache, void *obj)
755
{
756
	_slab_free(cache,obj,NULL);
757
}
758
 
759 palkovsky 759
/* Go through all caches and reclaim what is possible */
760
count_t slab_reclaim(int flags)
761
{
762
	slab_cache_t *cache;
763
	link_t *cur;
764
	count_t frames = 0;
765
 
766
	spinlock_lock(&slab_cache_lock);
767
 
776 palkovsky 768
	/* TODO: Add assert, that interrupts are disabled, otherwise
769
	 * memory allocation from interrupts can deadlock.
770
	 */
771
 
759 palkovsky 772
	for (cur = slab_cache_list.next;cur!=&slab_cache_list; cur=cur->next) {
773
		cache = list_get_instance(cur, slab_cache_t, link);
774
		frames += _slab_reclaim(cache, flags);
775
	}
776
 
777
	spinlock_unlock(&slab_cache_lock);
778
 
779
	return frames;
780
}
781
 
782
 
783
/* Print list of slabs */
784
void slab_print_list(void)
785
{
786
	slab_cache_t *cache;
787
	link_t *cur;
783 palkovsky 788
	ipl_t ipl;
789
 
790
	ipl = interrupts_disable();
759 palkovsky 791
	spinlock_lock(&slab_cache_lock);
1224 cejka 792
	printf("SLAB name\t  Osize\t  Pages\t Obj/pg\t  Slabs\t Cached\tAllocobjs\tCtl\n");
759 palkovsky 793
	for (cur = slab_cache_list.next;cur!=&slab_cache_list; cur=cur->next) {
794
		cache = list_get_instance(cur, slab_cache_t, link);
1224 cejka 795
		printf("%s\t%7zd\t%7zd\t%7zd\t%7zd\t%7zd\t%7zd\t\t%s\n", cache->name, cache->size, 
766 palkovsky 796
		       (1 << cache->order), cache->objects,
767 palkovsky 797
		       atomic_get(&cache->allocated_slabs),
798
		       atomic_get(&cache->cached_objs),
766 palkovsky 799
		       atomic_get(&cache->allocated_objs),
800
		       cache->flags & SLAB_CACHE_SLINSIDE ? "In" : "Out");
759 palkovsky 801
	}
802
	spinlock_unlock(&slab_cache_lock);
783 palkovsky 803
	interrupts_restore(ipl);
759 palkovsky 804
}
805
 
806
void slab_cache_init(void)
807
{
771 palkovsky 808
	int i, size;
809
 
759 palkovsky 810
	/* Initialize magazine cache */
811
	_slab_cache_create(&mag_cache,
812
			   "slab_magazine",
813
			   sizeof(slab_magazine_t)+SLAB_MAG_SIZE*sizeof(void*),
814
			   sizeof(__address),
815
			   NULL, NULL,
769 palkovsky 816
			   SLAB_CACHE_NOMAGAZINE | SLAB_CACHE_SLINSIDE);
817
	/* Initialize slab_cache cache */
818
	_slab_cache_create(&slab_cache_cache,
819
			   "slab_cache",
789 palkovsky 820
			   sizeof(slab_cache_cache),
769 palkovsky 821
			   sizeof(__address),
822
			   NULL, NULL,
823
			   SLAB_CACHE_NOMAGAZINE | SLAB_CACHE_SLINSIDE);
824
	/* Initialize external slab cache */
825
	slab_extern_cache = slab_cache_create("slab_extern",
826
					      sizeof(slab_t),
827
					      0, NULL, NULL,
789 palkovsky 828
					      SLAB_CACHE_SLINSIDE | SLAB_CACHE_MAGDEFERRED);
759 palkovsky 829
 
830
	/* Initialize structures for malloc */
771 palkovsky 831
	for (i=0, size=(1<<SLAB_MIN_MALLOC_W);
832
	     i < (SLAB_MAX_MALLOC_W-SLAB_MIN_MALLOC_W+1);
833
	     i++, size <<= 1) {
834
		malloc_caches[i] = slab_cache_create(malloc_names[i],
835
						     size, 0,
789 palkovsky 836
						     NULL,NULL, SLAB_CACHE_MAGDEFERRED);
771 palkovsky 837
	}
778 palkovsky 838
#ifdef CONFIG_DEBUG       
839
	_slab_initialized = 1;
840
#endif
759 palkovsky 841
}
771 palkovsky 842
 
789 palkovsky 843
/** Enable cpu_cache
844
 *
845
 * Kernel calls this function, when it knows the real number of
846
 * processors. 
847
 * Allocate slab for cpucache and enable it on all existing
848
 * slabs that are SLAB_CACHE_MAGDEFERRED
849
 */
850
void slab_enable_cpucache(void)
851
{
852
	link_t *cur;
853
	slab_cache_t *s;
854
 
791 palkovsky 855
#ifdef CONFIG_DEBUG
856
	_slab_initialized = 2;
857
#endif
858
 
789 palkovsky 859
	spinlock_lock(&slab_cache_lock);
860
 
861
	for (cur=slab_cache_list.next; cur != &slab_cache_list;cur=cur->next){
862
		s = list_get_instance(cur, slab_cache_t, link);
863
		if ((s->flags & SLAB_CACHE_MAGDEFERRED) != SLAB_CACHE_MAGDEFERRED)
864
			continue;
865
		make_magcache(s);
866
		s->flags &= ~SLAB_CACHE_MAGDEFERRED;
867
	}
868
 
869
	spinlock_unlock(&slab_cache_lock);
870
}
871
 
771 palkovsky 872
/**************************************/
873
/* kalloc/kfree functions             */
822 palkovsky 874
void * malloc(unsigned int size, int flags)
771 palkovsky 875
{
876
	int idx;
778 palkovsky 877
 
878
	ASSERT(_slab_initialized);
771 palkovsky 879
	ASSERT( size && size <= (1 << SLAB_MAX_MALLOC_W));
880
 
881
	if (size < (1 << SLAB_MIN_MALLOC_W))
882
		size = (1 << SLAB_MIN_MALLOC_W);
883
 
884
	idx = fnzb(size-1) - SLAB_MIN_MALLOC_W + 1;
885
 
886
	return slab_alloc(malloc_caches[idx], flags);
887
}
888
 
889
 
822 palkovsky 890
void free(void *obj)
771 palkovsky 891
{
781 palkovsky 892
	slab_t *slab;
893
 
894
	if (!obj) return;
895
 
896
	slab = obj2slab(obj);
771 palkovsky 897
	_slab_free(slab->cache, obj, slab);
898
}