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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
 
1757 jermar 29
/** @addtogroup genericmm
1702 cejka 30
 * @{
31
 */
32
 
1248 jermar 33
/**
1702 cejka 34
 * @file
1248 jermar 35
 * @brief	Slab allocator.
769 palkovsky 36
 *
1248 jermar 37
 * The slab allocator is closely modelled after OpenSolaris slab allocator.
38
 * @see http://www.usenix.org/events/usenix01/full_papers/bonwick/bonwick_html/
39
 *
769 palkovsky 40
 * with the following exceptions:
1248 jermar 41
 * @li empty slabs are deallocated immediately 
769 palkovsky 42
 *     (in Linux they are kept in linked list, in Solaris ???)
1248 jermar 43
 * @li empty magazines are deallocated when not needed
769 palkovsky 44
 *     (in Solaris they are held in linked list in slab cache)
45
 *
1248 jermar 46
 * Following features are not currently supported but would be easy to do:
47
 * @li cache coloring
48
 * @li dynamic magazine growing (different magazine sizes are already
1144 jermar 49
 *     supported, but we would need to adjust allocation strategy)
769 palkovsky 50
 *
1248 jermar 51
 * The slab allocator supports per-CPU caches ('magazines') to facilitate
769 palkovsky 52
 * good SMP scaling. 
53
 *
54
 * When a new object is being allocated, it is first checked, if it is 
1554 jermar 55
 * available in a CPU-bound magazine. If it is not found there, it is
56
 * allocated from a CPU-shared slab - if a partially full one is found,
57
 * it is used, otherwise a new one is allocated. 
769 palkovsky 58
 *
1554 jermar 59
 * When an object is being deallocated, it is put to a CPU-bound magazine.
60
 * If there is no such magazine, a new one is allocated (if this fails, 
1248 jermar 61
 * the object is deallocated into slab). If the magazine is full, it is
1554 jermar 62
 * put into cpu-shared list of magazines and a new one is allocated.
769 palkovsky 63
 *
1554 jermar 64
 * The CPU-bound magazine is actually a pair of magazines in order to avoid
769 palkovsky 65
 * thrashing when somebody is allocating/deallocating 1 item at the magazine
66
 * size boundary. LIFO order is enforced, which should avoid fragmentation
67
 * as much as possible. 
68
 *  
1554 jermar 69
 * Every cache contains list of full slabs and list of partially full slabs.
1248 jermar 70
 * Empty slabs are immediately freed (thrashing will be avoided because
769 palkovsky 71
 * of magazines). 
72
 *
1248 jermar 73
 * The slab information structure is kept inside the data area, if possible.
769 palkovsky 74
 * The cache can be marked that it should not use magazines. This is used
1248 jermar 75
 * only for slab related caches to avoid deadlocks and infinite recursion
76
 * (the slab allocator uses itself for allocating all it's control structures).
769 palkovsky 77
 *
1554 jermar 78
 * The slab allocator allocates a lot of space and does not free it. When
79
 * the frame allocator fails to allocate a frame, it calls slab_reclaim().
769 palkovsky 80
 * It tries 'light reclaim' first, then brutal reclaim. The light reclaim
81
 * releases slabs from cpu-shared magazine-list, until at least 1 slab 
82
 * is deallocated in each cache (this algorithm should probably change).
83
 * The brutal reclaim removes all cached objects, even from CPU-bound
84
 * magazines.
85
 *
1757 jermar 86
 * @todo
1248 jermar 87
 * For better CPU-scaling the magazine allocation strategy should
775 palkovsky 88
 * be extended. Currently, if the cache does not have magazine, it asks
89
 * for non-cpu cached magazine cache to provide one. It might be feasible
90
 * to add cpu-cached magazine cache (which would allocate it's magazines
91
 * from non-cpu-cached mag. cache). This would provide a nice per-cpu
92
 * buffer. The other possibility is to use the per-cache 
93
 * 'empty-magazine-list', which decreases competing for 1 per-system
94
 * magazine cache.
95
 *
1757 jermar 96
 * @todo
97
 * it might be good to add granularity of locks even to slab level,
98
 * we could then try_spinlock over all partial slabs and thus improve
99
 * scalability even on slab level
769 palkovsky 100
 */
101
 
759 palkovsky 102
#include <synch/spinlock.h>
103
#include <mm/slab.h>
788 jermar 104
#include <adt/list.h>
759 palkovsky 105
#include <memstr.h>
106
#include <align.h>
762 palkovsky 107
#include <mm/frame.h>
759 palkovsky 108
#include <config.h>
109
#include <print.h>
110
#include <arch.h>
111
#include <panic.h>
762 palkovsky 112
#include <debug.h>
771 palkovsky 113
#include <bitops.h>
759 palkovsky 114
 
115
SPINLOCK_INITIALIZE(slab_cache_lock);
769 palkovsky 116
static LIST_INITIALIZE(slab_cache_list);
759 palkovsky 117
 
769 palkovsky 118
/** Magazine cache */
119
static slab_cache_t mag_cache;
120
/** Cache for cache descriptors */
121
static slab_cache_t slab_cache_cache;
122
/** Cache for external slab descriptors
123
 * This time we want per-cpu cache, so do not make it static
1248 jermar 124
 * - using slab for internal slab structures will not deadlock,
769 palkovsky 125
 *   as all slab structures are 'small' - control structures of
126
 *   their caches do not require further allocation
127
 */
128
static slab_cache_t *slab_extern_cache;
771 palkovsky 129
/** Caches for malloc */
130
static slab_cache_t *malloc_caches[SLAB_MAX_MALLOC_W-SLAB_MIN_MALLOC_W+1];
131
char *malloc_names[] =  {
791 palkovsky 132
	"malloc-16","malloc-32","malloc-64","malloc-128",
771 palkovsky 133
	"malloc-256","malloc-512","malloc-1K","malloc-2K",
134
	"malloc-4K","malloc-8K","malloc-16K","malloc-32K",
1428 palkovsky 135
	"malloc-64K","malloc-128K","malloc-256K"
771 palkovsky 136
};
762 palkovsky 137
 
769 palkovsky 138
/** Slab descriptor */
762 palkovsky 139
typedef struct {
140
	slab_cache_t *cache; /**< Pointer to parent cache */
141
	link_t link;       /* List of full/partial slabs */
142
	void *start;       /**< Start address of first available item */
143
	count_t available; /**< Count of available items in this slab */
144
	index_t nextavail; /**< The index of next available item */
145
}slab_t;
146
 
791 palkovsky 147
#ifdef CONFIG_DEBUG
148
static int _slab_initialized = 0;
149
#endif
150
 
759 palkovsky 151
/**************************************/
1248 jermar 152
/* Slab allocation functions          */
759 palkovsky 153
 
762 palkovsky 154
/**
155
 * Allocate frames for slab space and initialize
156
 *
157
 */
158
static slab_t * slab_space_alloc(slab_cache_t *cache, int flags)
159
{
160
	void *data;
161
	slab_t *slab;
162
	size_t fsize;
163
	int i;
814 palkovsky 164
	int zone=0;
165
 
1766 palkovsky 166
	data = frame_alloc_generic(cache->order, FRAME_KA | flags, &zone);
167
	if (!data) {
762 palkovsky 168
		return NULL;
764 palkovsky 169
	}
768 palkovsky 170
	if (! (cache->flags & SLAB_CACHE_SLINSIDE)) {
769 palkovsky 171
		slab = slab_alloc(slab_extern_cache, flags);
762 palkovsky 172
		if (!slab) {
1760 palkovsky 173
			frame_free(KA2PA(data));
762 palkovsky 174
			return NULL;
175
		}
176
	} else {
177
		fsize = (PAGE_SIZE << cache->order);
178
		slab = data + fsize - sizeof(*slab);
179
	}
1288 jermar 180
 
762 palkovsky 181
	/* Fill in slab structures */
814 palkovsky 182
	for (i=0; i < (1 << cache->order); i++)
1760 palkovsky 183
		frame_set_parent(ADDR2PFN(KA2PA(data))+i, slab, zone);
762 palkovsky 184
 
185
	slab->start = data;
186
	slab->available = cache->objects;
187
	slab->nextavail = 0;
767 palkovsky 188
	slab->cache = cache;
762 palkovsky 189
 
190
	for (i=0; i<cache->objects;i++)
191
		*((int *) (slab->start + i*cache->size)) = i+1;
764 palkovsky 192
 
193
	atomic_inc(&cache->allocated_slabs);
762 palkovsky 194
	return slab;
195
}
196
 
759 palkovsky 197
/**
1248 jermar 198
 * Deallocate space associated with slab
762 palkovsky 199
 *
200
 * @return number of freed frames
201
 */
202
static count_t slab_space_free(slab_cache_t *cache, slab_t *slab)
203
{
1760 palkovsky 204
	frame_free(KA2PA(slab->start));
768 palkovsky 205
	if (! (cache->flags & SLAB_CACHE_SLINSIDE))
769 palkovsky 206
		slab_free(slab_extern_cache, slab);
764 palkovsky 207
 
208
	atomic_dec(&cache->allocated_slabs);
209
 
762 palkovsky 210
	return 1 << cache->order;
211
}
212
 
213
/** Map object to slab structure */
214
static slab_t * obj2slab(void *obj)
215
{
814 palkovsky 216
	return (slab_t *)frame_get_parent(ADDR2PFN(KA2PA(obj)), 0);
762 palkovsky 217
}
218
 
219
/**************************************/
1248 jermar 220
/* Slab functions */
762 palkovsky 221
 
222
 
223
/**
759 palkovsky 224
 * Return object to slab and call a destructor
225
 *
762 palkovsky 226
 * @param slab If the caller knows directly slab of the object, otherwise NULL
227
 *
759 palkovsky 228
 * @return Number of freed pages
229
 */
762 palkovsky 230
static count_t slab_obj_destroy(slab_cache_t *cache, void *obj,
231
				slab_t *slab)
759 palkovsky 232
{
787 palkovsky 233
	int freed = 0;
234
 
762 palkovsky 235
	if (!slab)
236
		slab = obj2slab(obj);
237
 
767 palkovsky 238
	ASSERT(slab->cache == cache);
239
 
787 palkovsky 240
	if (cache->destructor)
241
		freed = cache->destructor(obj);
242
 
776 palkovsky 243
	spinlock_lock(&cache->slablock);
789 palkovsky 244
	ASSERT(slab->available < cache->objects);
776 palkovsky 245
 
762 palkovsky 246
	*((int *)obj) = slab->nextavail;
247
	slab->nextavail = (obj - slab->start)/cache->size;
248
	slab->available++;
249
 
250
	/* Move it to correct list */
251
	if (slab->available == cache->objects) {
252
		/* Free associated memory */
253
		list_remove(&slab->link);
782 palkovsky 254
		spinlock_unlock(&cache->slablock);
255
 
787 palkovsky 256
		return freed + slab_space_free(cache, slab);
782 palkovsky 257
 
780 palkovsky 258
	} else if (slab->available == 1) {
259
		/* It was in full, move to partial */
260
		list_remove(&slab->link);
261
		list_prepend(&slab->link, &cache->partial_slabs);
762 palkovsky 262
	}
783 palkovsky 263
	spinlock_unlock(&cache->slablock);
787 palkovsky 264
	return freed;
759 palkovsky 265
}
266
 
267
/**
268
 * Take new object from slab or create new if needed
269
 *
270
 * @return Object address or null
271
 */
272
static void * slab_obj_create(slab_cache_t *cache, int flags)
273
{
762 palkovsky 274
	slab_t *slab;
275
	void *obj;
276
 
776 palkovsky 277
	spinlock_lock(&cache->slablock);
278
 
762 palkovsky 279
	if (list_empty(&cache->partial_slabs)) {
280
		/* Allow recursion and reclaiming
1248 jermar 281
		 * - this should work, as the slab control structures
1288 jermar 282
		 *   are small and do not need to allocate with anything
283
		 *   other than frame_alloc when they are allocating,
762 palkovsky 284
		 *   that's why we should get recursion at most 1-level deep
285
		 */
776 palkovsky 286
		spinlock_unlock(&cache->slablock);
762 palkovsky 287
		slab = slab_space_alloc(cache, flags);
780 palkovsky 288
		if (!slab)
289
			return NULL;
776 palkovsky 290
		spinlock_lock(&cache->slablock);
762 palkovsky 291
	} else {
292
		slab = list_get_instance(cache->partial_slabs.next,
293
					 slab_t,
294
					 link);
295
		list_remove(&slab->link);
296
	}
297
	obj = slab->start + slab->nextavail * cache->size;
298
	slab->nextavail = *((int *)obj);
299
	slab->available--;
787 palkovsky 300
 
762 palkovsky 301
	if (! slab->available)
764 palkovsky 302
		list_prepend(&slab->link, &cache->full_slabs);
762 palkovsky 303
	else
764 palkovsky 304
		list_prepend(&slab->link, &cache->partial_slabs);
776 palkovsky 305
 
306
	spinlock_unlock(&cache->slablock);
787 palkovsky 307
 
308
	if (cache->constructor && cache->constructor(obj, flags)) {
309
		/* Bad, bad, construction failed */
310
		slab_obj_destroy(cache, obj, slab);
311
		return NULL;
312
	}
762 palkovsky 313
	return obj;
759 palkovsky 314
}
315
 
316
/**************************************/
317
/* CPU-Cache slab functions */
318
 
319
/**
781 palkovsky 320
 * Finds a full magazine in cache, takes it from list
321
 * and returns it 
322
 *
323
 * @param first If true, return first, else last mag
324
 */
325
static slab_magazine_t * get_mag_from_cache(slab_cache_t *cache,
326
					    int first)
327
{
328
	slab_magazine_t *mag = NULL;
329
	link_t *cur;
330
 
331
	spinlock_lock(&cache->maglock);
332
	if (!list_empty(&cache->magazines)) {
333
		if (first)
334
			cur = cache->magazines.next;
335
		else
336
			cur = cache->magazines.prev;
337
		mag = list_get_instance(cur, slab_magazine_t, link);
338
		list_remove(&mag->link);
339
		atomic_dec(&cache->magazine_counter);
340
	}
341
	spinlock_unlock(&cache->maglock);
342
	return mag;
343
}
344
 
345
/** Prepend magazine to magazine list in cache */
346
static void put_mag_to_cache(slab_cache_t *cache, slab_magazine_t *mag)
347
{
348
	spinlock_lock(&cache->maglock);
349
 
350
	list_prepend(&mag->link, &cache->magazines);
351
	atomic_inc(&cache->magazine_counter);
352
 
353
	spinlock_unlock(&cache->maglock);
354
}
355
 
356
/**
759 palkovsky 357
 * Free all objects in magazine and free memory associated with magazine
358
 *
359
 * @return Number of freed pages
360
 */
361
static count_t magazine_destroy(slab_cache_t *cache, 
362
				slab_magazine_t *mag)
363
{
364
	int i;
365
	count_t frames = 0;
366
 
767 palkovsky 367
	for (i=0;i < mag->busy; i++) {
762 palkovsky 368
		frames += slab_obj_destroy(cache, mag->objs[i], NULL);
767 palkovsky 369
		atomic_dec(&cache->cached_objs);
370
	}
759 palkovsky 371
 
372
	slab_free(&mag_cache, mag);
373
 
374
	return frames;
375
}
376
 
377
/**
769 palkovsky 378
 * Find full magazine, set it as current and return it
379
 *
380
 * Assume cpu_magazine lock is held
381
 */
382
static slab_magazine_t * get_full_current_mag(slab_cache_t *cache)
383
{
384
	slab_magazine_t *cmag, *lastmag, *newmag;
385
 
386
	cmag = cache->mag_cache[CPU->id].current;
387
	lastmag = cache->mag_cache[CPU->id].last;
388
	if (cmag) { /* First try local CPU magazines */
389
		if (cmag->busy)
390
			return cmag;
391
 
392
		if (lastmag && lastmag->busy) {
393
			cache->mag_cache[CPU->id].current = lastmag;
394
			cache->mag_cache[CPU->id].last = cmag;
395
			return lastmag;
396
		}
397
	}
398
	/* Local magazines are empty, import one from magazine list */
781 palkovsky 399
	newmag = get_mag_from_cache(cache, 1);
400
	if (!newmag)
769 palkovsky 401
		return NULL;
402
 
403
	if (lastmag)
781 palkovsky 404
		magazine_destroy(cache, lastmag);
405
 
769 palkovsky 406
	cache->mag_cache[CPU->id].last = cmag;
407
	cache->mag_cache[CPU->id].current = newmag;
408
	return newmag;
409
}
410
 
411
/**
759 palkovsky 412
 * Try to find object in CPU-cache magazines
413
 *
414
 * @return Pointer to object or NULL if not available
415
 */
416
static void * magazine_obj_get(slab_cache_t *cache)
417
{
418
	slab_magazine_t *mag;
767 palkovsky 419
	void *obj;
759 palkovsky 420
 
772 palkovsky 421
	if (!CPU)
422
		return NULL;
423
 
759 palkovsky 424
	spinlock_lock(&cache->mag_cache[CPU->id].lock);
425
 
769 palkovsky 426
	mag = get_full_current_mag(cache);
427
	if (!mag) {
428
		spinlock_unlock(&cache->mag_cache[CPU->id].lock);
429
		return NULL;
759 palkovsky 430
	}
767 palkovsky 431
	obj = mag->objs[--mag->busy];
759 palkovsky 432
	spinlock_unlock(&cache->mag_cache[CPU->id].lock);
767 palkovsky 433
	atomic_dec(&cache->cached_objs);
434
 
435
	return obj;
759 palkovsky 436
}
437
 
438
/**
768 palkovsky 439
 * Assure that the current magazine is empty, return pointer to it, or NULL if 
769 palkovsky 440
 * no empty magazine is available and cannot be allocated
759 palkovsky 441
 *
773 palkovsky 442
 * Assume mag_cache[CPU->id].lock is held
443
 *
759 palkovsky 444
 * We have 2 magazines bound to processor. 
445
 * First try the current. 
446
 *  If full, try the last.
447
 *   If full, put to magazines list.
448
 *   allocate new, exchange last & current
449
 *
768 palkovsky 450
 */
451
static slab_magazine_t * make_empty_current_mag(slab_cache_t *cache)
452
{
453
	slab_magazine_t *cmag,*lastmag,*newmag;
454
 
455
	cmag = cache->mag_cache[CPU->id].current;
456
	lastmag = cache->mag_cache[CPU->id].last;
457
 
458
	if (cmag) {
459
		if (cmag->busy < cmag->size)
460
			return cmag;
461
		if (lastmag && lastmag->busy < lastmag->size) {
462
			cache->mag_cache[CPU->id].last = cmag;
463
			cache->mag_cache[CPU->id].current = lastmag;
464
			return lastmag;
465
		}
466
	}
467
	/* current | last are full | nonexistent, allocate new */
468
	/* We do not want to sleep just because of caching */
469
	/* Especially we do not want reclaiming to start, as 
470
	 * this would deadlock */
471
	newmag = slab_alloc(&mag_cache, FRAME_ATOMIC | FRAME_NO_RECLAIM);
472
	if (!newmag)
473
		return NULL;
474
	newmag->size = SLAB_MAG_SIZE;
475
	newmag->busy = 0;
476
 
477
	/* Flush last to magazine list */
781 palkovsky 478
	if (lastmag)
479
		put_mag_to_cache(cache, lastmag);
480
 
768 palkovsky 481
	/* Move current as last, save new as current */
482
	cache->mag_cache[CPU->id].last = cmag;	
483
	cache->mag_cache[CPU->id].current = newmag;	
484
 
485
	return newmag;
486
}
487
 
488
/**
489
 * Put object into CPU-cache magazine
490
 *
759 palkovsky 491
 * @return 0 - success, -1 - could not get memory
492
 */
493
static int magazine_obj_put(slab_cache_t *cache, void *obj)
494
{
495
	slab_magazine_t *mag;
496
 
772 palkovsky 497
	if (!CPU)
498
		return -1;
499
 
759 palkovsky 500
	spinlock_lock(&cache->mag_cache[CPU->id].lock);
768 palkovsky 501
 
502
	mag = make_empty_current_mag(cache);
769 palkovsky 503
	if (!mag) {
504
		spinlock_unlock(&cache->mag_cache[CPU->id].lock);
505
		return -1;
506
	}
759 palkovsky 507
 
508
	mag->objs[mag->busy++] = obj;
509
 
510
	spinlock_unlock(&cache->mag_cache[CPU->id].lock);
767 palkovsky 511
	atomic_inc(&cache->cached_objs);
759 palkovsky 512
	return 0;
513
}
514
 
515
 
516
/**************************************/
1248 jermar 517
/* Slab cache functions */
759 palkovsky 518
 
762 palkovsky 519
/** Return number of objects that fit in certain cache size */
520
static int comp_objects(slab_cache_t *cache)
521
{
522
	if (cache->flags & SLAB_CACHE_SLINSIDE)
523
		return ((PAGE_SIZE << cache->order) - sizeof(slab_t)) / cache->size;
524
	else 
525
		return (PAGE_SIZE << cache->order) / cache->size;
526
}
527
 
528
/** Return wasted space in slab */
529
static int badness(slab_cache_t *cache)
530
{
531
	int objects;
532
	int ssize;
533
 
534
	objects = comp_objects(cache);
535
	ssize = PAGE_SIZE << cache->order;
536
	if (cache->flags & SLAB_CACHE_SLINSIDE)
537
		ssize -= sizeof(slab_t);
538
	return ssize - objects*cache->size;
539
}
540
 
789 palkovsky 541
/**
542
 * Initialize mag_cache structure in slab cache
543
 */
544
static void make_magcache(slab_cache_t *cache)
545
{
546
	int i;
791 palkovsky 547
 
548
	ASSERT(_slab_initialized >= 2);
789 palkovsky 549
 
822 palkovsky 550
	cache->mag_cache = malloc(sizeof(slab_mag_cache_t)*config.cpu_count,0);
789 palkovsky 551
	for (i=0; i < config.cpu_count; i++) {
1780 jermar 552
		memsetb((uintptr_t)&cache->mag_cache[i],
789 palkovsky 553
			sizeof(cache->mag_cache[i]), 0);
554
		spinlock_initialize(&cache->mag_cache[i].lock, 
555
				    "slab_maglock_cpu");
556
	}
557
}
558
 
759 palkovsky 559
/** Initialize allocated memory as a slab cache */
560
static void
561
_slab_cache_create(slab_cache_t *cache,
562
		   char *name,
563
		   size_t size,
564
		   size_t align,
565
		   int (*constructor)(void *obj, int kmflag),
787 palkovsky 566
		   int (*destructor)(void *obj),
759 palkovsky 567
		   int flags)
568
{
771 palkovsky 569
	int pages;
783 palkovsky 570
	ipl_t ipl;
759 palkovsky 571
 
1780 jermar 572
	memsetb((uintptr_t)cache, sizeof(*cache), 0);
759 palkovsky 573
	cache->name = name;
574
 
1780 jermar 575
	if (align < sizeof(unative_t))
576
		align = sizeof(unative_t);
766 palkovsky 577
	size = ALIGN_UP(size, align);
578
 
762 palkovsky 579
	cache->size = size;
759 palkovsky 580
 
581
	cache->constructor = constructor;
582
	cache->destructor = destructor;
583
	cache->flags = flags;
584
 
585
	list_initialize(&cache->full_slabs);
586
	list_initialize(&cache->partial_slabs);
587
	list_initialize(&cache->magazines);
776 palkovsky 588
	spinlock_initialize(&cache->slablock, "slab_lock");
589
	spinlock_initialize(&cache->maglock, "slab_maglock");
789 palkovsky 590
	if (! (cache->flags & SLAB_CACHE_NOMAGAZINE))
591
		make_magcache(cache);
759 palkovsky 592
 
593
	/* Compute slab sizes, object counts in slabs etc. */
594
	if (cache->size < SLAB_INSIDE_SIZE)
595
		cache->flags |= SLAB_CACHE_SLINSIDE;
596
 
762 palkovsky 597
	/* Minimum slab order */
1682 palkovsky 598
	pages = SIZE2FRAMES(cache->size);
1677 palkovsky 599
	/* We need the 2^order >= pages */
600
	if (pages == 1)
601
		cache->order = 0;
602
	else
603
		cache->order = fnzb(pages-1)+1;
766 palkovsky 604
 
762 palkovsky 605
	while (badness(cache) > SLAB_MAX_BADNESS(cache)) {
606
		cache->order += 1;
607
	}
608
	cache->objects = comp_objects(cache);
766 palkovsky 609
	/* If info fits in, put it inside */
610
	if (badness(cache) > sizeof(slab_t))
611
		cache->flags |= SLAB_CACHE_SLINSIDE;
762 palkovsky 612
 
783 palkovsky 613
	/* Add cache to cache list */
614
	ipl = interrupts_disable();
759 palkovsky 615
	spinlock_lock(&slab_cache_lock);
616
 
617
	list_append(&cache->link, &slab_cache_list);
618
 
619
	spinlock_unlock(&slab_cache_lock);
783 palkovsky 620
	interrupts_restore(ipl);
759 palkovsky 621
}
622
 
623
/** Create slab cache  */
624
slab_cache_t * slab_cache_create(char *name,
625
				 size_t size,
626
				 size_t align,
627
				 int (*constructor)(void *obj, int kmflag),
787 palkovsky 628
				 int (*destructor)(void *obj),
759 palkovsky 629
				 int flags)
630
{
631
	slab_cache_t *cache;
632
 
769 palkovsky 633
	cache = slab_alloc(&slab_cache_cache, 0);
759 palkovsky 634
	_slab_cache_create(cache, name, size, align, constructor, destructor,
635
			   flags);
636
	return cache;
637
}
638
 
639
/** 
640
 * Reclaim space occupied by objects that are already free
641
 *
642
 * @param flags If contains SLAB_RECLAIM_ALL, do aggressive freeing
643
 * @return Number of freed pages
644
 */
645
static count_t _slab_reclaim(slab_cache_t *cache, int flags)
646
{
647
	int i;
648
	slab_magazine_t *mag;
649
	count_t frames = 0;
781 palkovsky 650
	int magcount;
759 palkovsky 651
 
652
	if (cache->flags & SLAB_CACHE_NOMAGAZINE)
653
		return 0; /* Nothing to do */
781 palkovsky 654
 
655
	/* We count up to original magazine count to avoid
656
	 * endless loop 
657
	 */
658
	magcount = atomic_get(&cache->magazine_counter);
659
	while (magcount-- && (mag=get_mag_from_cache(cache,0))) {
660
		frames += magazine_destroy(cache,mag);
661
		if (!(flags & SLAB_RECLAIM_ALL) && frames)
662
			break;
769 palkovsky 663
	}
759 palkovsky 664
 
665
	if (flags & SLAB_RECLAIM_ALL) {
781 palkovsky 666
		/* Free cpu-bound magazines */
759 palkovsky 667
		/* Destroy CPU magazines */
668
		for (i=0; i<config.cpu_count; i++) {
781 palkovsky 669
			spinlock_lock(&cache->mag_cache[i].lock);
670
 
759 palkovsky 671
			mag = cache->mag_cache[i].current;
672
			if (mag)
673
				frames += magazine_destroy(cache, mag);
674
			cache->mag_cache[i].current = NULL;
675
 
676
			mag = cache->mag_cache[i].last;
677
			if (mag)
678
				frames += magazine_destroy(cache, mag);
679
			cache->mag_cache[i].last = NULL;
781 palkovsky 680
 
681
			spinlock_unlock(&cache->mag_cache[i].lock);
759 palkovsky 682
		}
683
	}
767 palkovsky 684
 
759 palkovsky 685
	return frames;
686
}
687
 
688
/** Check that there are no slabs and remove cache from system  */
689
void slab_cache_destroy(slab_cache_t *cache)
690
{
781 palkovsky 691
	ipl_t ipl;
692
 
693
	/* First remove cache from link, so that we don't need
694
	 * to disable interrupts later
695
	 */
696
 
697
	ipl = interrupts_disable();
698
	spinlock_lock(&slab_cache_lock);
699
 
700
	list_remove(&cache->link);
701
 
702
	spinlock_unlock(&slab_cache_lock);
703
	interrupts_restore(ipl);
704
 
759 palkovsky 705
	/* Do not lock anything, we assume the software is correct and
706
	 * does not touch the cache when it decides to destroy it */
707
 
708
	/* Destroy all magazines */
709
	_slab_reclaim(cache, SLAB_RECLAIM_ALL);
710
 
711
	/* All slabs must be empty */
712
	if (!list_empty(&cache->full_slabs) \
713
	    || !list_empty(&cache->partial_slabs))
714
		panic("Destroying cache that is not empty.");
715
 
789 palkovsky 716
	if (!(cache->flags & SLAB_CACHE_NOMAGAZINE))
822 palkovsky 717
		free(cache->mag_cache);
769 palkovsky 718
	slab_free(&slab_cache_cache, cache);
759 palkovsky 719
}
720
 
721
/** Allocate new object from cache - if no flags given, always returns 
722
    memory */
723
void * slab_alloc(slab_cache_t *cache, int flags)
724
{
725
	ipl_t ipl;
726
	void *result = NULL;
773 palkovsky 727
 
759 palkovsky 728
	/* Disable interrupts to avoid deadlocks with interrupt handlers */
729
	ipl = interrupts_disable();
771 palkovsky 730
 
814 palkovsky 731
	if (!(cache->flags & SLAB_CACHE_NOMAGAZINE)) {
759 palkovsky 732
		result = magazine_obj_get(cache);
814 palkovsky 733
	}
776 palkovsky 734
	if (!result)
759 palkovsky 735
		result = slab_obj_create(cache, flags);
736
 
769 palkovsky 737
	interrupts_restore(ipl);
738
 
764 palkovsky 739
	if (result)
740
		atomic_inc(&cache->allocated_objs);
741
 
759 palkovsky 742
	return result;
743
}
744
 
771 palkovsky 745
/** Return object to cache, use slab if known  */
746
static void _slab_free(slab_cache_t *cache, void *obj, slab_t *slab)
759 palkovsky 747
{
748
	ipl_t ipl;
749
 
750
	ipl = interrupts_disable();
751
 
762 palkovsky 752
	if ((cache->flags & SLAB_CACHE_NOMAGAZINE) \
753
	    || magazine_obj_put(cache, obj)) {
776 palkovsky 754
 
771 palkovsky 755
		slab_obj_destroy(cache, obj, slab);
776 palkovsky 756
 
759 palkovsky 757
	}
769 palkovsky 758
	interrupts_restore(ipl);
764 palkovsky 759
	atomic_dec(&cache->allocated_objs);
759 palkovsky 760
}
761
 
771 palkovsky 762
/** Return slab object to cache */
763
void slab_free(slab_cache_t *cache, void *obj)
764
{
765
	_slab_free(cache,obj,NULL);
766
}
767
 
759 palkovsky 768
/* Go through all caches and reclaim what is possible */
769
count_t slab_reclaim(int flags)
770
{
771
	slab_cache_t *cache;
772
	link_t *cur;
773
	count_t frames = 0;
774
 
775
	spinlock_lock(&slab_cache_lock);
776
 
776 palkovsky 777
	/* TODO: Add assert, that interrupts are disabled, otherwise
778
	 * memory allocation from interrupts can deadlock.
779
	 */
780
 
759 palkovsky 781
	for (cur = slab_cache_list.next;cur!=&slab_cache_list; cur=cur->next) {
782
		cache = list_get_instance(cur, slab_cache_t, link);
783
		frames += _slab_reclaim(cache, flags);
784
	}
785
 
786
	spinlock_unlock(&slab_cache_lock);
787
 
788
	return frames;
789
}
790
 
791
 
792
/* Print list of slabs */
793
void slab_print_list(void)
794
{
795
	slab_cache_t *cache;
796
	link_t *cur;
783 palkovsky 797
	ipl_t ipl;
798
 
799
	ipl = interrupts_disable();
759 palkovsky 800
	spinlock_lock(&slab_cache_lock);
1248 jermar 801
	printf("slab name\t  Osize\t  Pages\t Obj/pg\t  Slabs\t Cached\tAllocobjs\tCtl\n");
759 palkovsky 802
	for (cur = slab_cache_list.next;cur!=&slab_cache_list; cur=cur->next) {
803
		cache = list_get_instance(cur, slab_cache_t, link);
1224 cejka 804
		printf("%s\t%7zd\t%7zd\t%7zd\t%7zd\t%7zd\t%7zd\t\t%s\n", cache->name, cache->size, 
766 palkovsky 805
		       (1 << cache->order), cache->objects,
767 palkovsky 806
		       atomic_get(&cache->allocated_slabs),
807
		       atomic_get(&cache->cached_objs),
766 palkovsky 808
		       atomic_get(&cache->allocated_objs),
809
		       cache->flags & SLAB_CACHE_SLINSIDE ? "In" : "Out");
759 palkovsky 810
	}
811
	spinlock_unlock(&slab_cache_lock);
783 palkovsky 812
	interrupts_restore(ipl);
759 palkovsky 813
}
814
 
815
void slab_cache_init(void)
816
{
771 palkovsky 817
	int i, size;
818
 
759 palkovsky 819
	/* Initialize magazine cache */
820
	_slab_cache_create(&mag_cache,
821
			   "slab_magazine",
822
			   sizeof(slab_magazine_t)+SLAB_MAG_SIZE*sizeof(void*),
1780 jermar 823
			   sizeof(uintptr_t),
759 palkovsky 824
			   NULL, NULL,
769 palkovsky 825
			   SLAB_CACHE_NOMAGAZINE | SLAB_CACHE_SLINSIDE);
826
	/* Initialize slab_cache cache */
827
	_slab_cache_create(&slab_cache_cache,
828
			   "slab_cache",
789 palkovsky 829
			   sizeof(slab_cache_cache),
1780 jermar 830
			   sizeof(uintptr_t),
769 palkovsky 831
			   NULL, NULL,
832
			   SLAB_CACHE_NOMAGAZINE | SLAB_CACHE_SLINSIDE);
833
	/* Initialize external slab cache */
834
	slab_extern_cache = slab_cache_create("slab_extern",
835
					      sizeof(slab_t),
836
					      0, NULL, NULL,
789 palkovsky 837
					      SLAB_CACHE_SLINSIDE | SLAB_CACHE_MAGDEFERRED);
759 palkovsky 838
 
839
	/* Initialize structures for malloc */
771 palkovsky 840
	for (i=0, size=(1<<SLAB_MIN_MALLOC_W);
841
	     i < (SLAB_MAX_MALLOC_W-SLAB_MIN_MALLOC_W+1);
842
	     i++, size <<= 1) {
843
		malloc_caches[i] = slab_cache_create(malloc_names[i],
844
						     size, 0,
789 palkovsky 845
						     NULL,NULL, SLAB_CACHE_MAGDEFERRED);
771 palkovsky 846
	}
778 palkovsky 847
#ifdef CONFIG_DEBUG       
848
	_slab_initialized = 1;
849
#endif
759 palkovsky 850
}
771 palkovsky 851
 
789 palkovsky 852
/** Enable cpu_cache
853
 *
854
 * Kernel calls this function, when it knows the real number of
855
 * processors. 
856
 * Allocate slab for cpucache and enable it on all existing
857
 * slabs that are SLAB_CACHE_MAGDEFERRED
858
 */
859
void slab_enable_cpucache(void)
860
{
861
	link_t *cur;
862
	slab_cache_t *s;
863
 
791 palkovsky 864
#ifdef CONFIG_DEBUG
865
	_slab_initialized = 2;
866
#endif
867
 
789 palkovsky 868
	spinlock_lock(&slab_cache_lock);
869
 
870
	for (cur=slab_cache_list.next; cur != &slab_cache_list;cur=cur->next){
871
		s = list_get_instance(cur, slab_cache_t, link);
872
		if ((s->flags & SLAB_CACHE_MAGDEFERRED) != SLAB_CACHE_MAGDEFERRED)
873
			continue;
874
		make_magcache(s);
875
		s->flags &= ~SLAB_CACHE_MAGDEFERRED;
876
	}
877
 
878
	spinlock_unlock(&slab_cache_lock);
879
}
880
 
771 palkovsky 881
/**************************************/
882
/* kalloc/kfree functions             */
822 palkovsky 883
void * malloc(unsigned int size, int flags)
771 palkovsky 884
{
885
	int idx;
778 palkovsky 886
 
887
	ASSERT(_slab_initialized);
1288 jermar 888
	ASSERT(size && size <= (1 << SLAB_MAX_MALLOC_W));
771 palkovsky 889
 
890
	if (size < (1 << SLAB_MIN_MALLOC_W))
891
		size = (1 << SLAB_MIN_MALLOC_W);
892
 
893
	idx = fnzb(size-1) - SLAB_MIN_MALLOC_W + 1;
894
 
895
	return slab_alloc(malloc_caches[idx], flags);
896
}
897
 
822 palkovsky 898
void free(void *obj)
771 palkovsky 899
{
781 palkovsky 900
	slab_t *slab;
901
 
902
	if (!obj) return;
903
 
904
	slab = obj2slab(obj);
771 palkovsky 905
	_slab_free(slab->cache, obj, slab);
906
}
1702 cejka 907
 
1757 jermar 908
/** @}
1702 cejka 909
 */