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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
 
1248 jermar 29
/**
30
 * @file    slab.c
31
 * @brief   Slab allocator.
769 palkovsky 32
 *
1248 jermar 33
 * The slab allocator is closely modelled after OpenSolaris slab allocator.
34
 * @see http://www.usenix.org/events/usenix01/full_papers/bonwick/bonwick_html/
35
 *
769 palkovsky 36
 * with the following exceptions:
1248 jermar 37
 * @li empty slabs are deallocated immediately
769 palkovsky 38
 *     (in Linux they are kept in linked list, in Solaris ???)
1248 jermar 39
 * @li empty magazines are deallocated when not needed
769 palkovsky 40
 *     (in Solaris they are held in linked list in slab cache)
41
 *
1248 jermar 42
 * Following features are not currently supported but would be easy to do:
43
 * @li cache coloring
44
 * @li dynamic magazine growing (different magazine sizes are already
1144 jermar 45
 *     supported, but we would need to adjust allocation strategy)
769 palkovsky 46
 *
1248 jermar 47
 * The slab allocator supports per-CPU caches ('magazines') to facilitate
769 palkovsky 48
 * good SMP scaling.
49
 *
50
 * When a new object is being allocated, it is first checked, if it is
1554 jermar 51
 * available in a CPU-bound magazine. If it is not found there, it is
52
 * allocated from a CPU-shared slab - if a partially full one is found,
53
 * it is used, otherwise a new one is allocated.
769 palkovsky 54
 *
1554 jermar 55
 * When an object is being deallocated, it is put to a CPU-bound magazine.
56
 * If there is no such magazine, a new one is allocated (if this fails,
1248 jermar 57
 * the object is deallocated into slab). If the magazine is full, it is
1554 jermar 58
 * put into cpu-shared list of magazines and a new one is allocated.
769 palkovsky 59
 *
1554 jermar 60
 * The CPU-bound magazine is actually a pair of magazines in order to avoid
769 palkovsky 61
 * thrashing when somebody is allocating/deallocating 1 item at the magazine
62
 * size boundary. LIFO order is enforced, which should avoid fragmentation
63
 * as much as possible.
64
 *  
1554 jermar 65
 * Every cache contains list of full slabs and list of partially full slabs.
1248 jermar 66
 * Empty slabs are immediately freed (thrashing will be avoided because
769 palkovsky 67
 * of magazines).
68
 *
1248 jermar 69
 * The slab information structure is kept inside the data area, if possible.
769 palkovsky 70
 * The cache can be marked that it should not use magazines. This is used
1248 jermar 71
 * only for slab related caches to avoid deadlocks and infinite recursion
72
 * (the slab allocator uses itself for allocating all it's control structures).
769 palkovsky 73
 *
1554 jermar 74
 * The slab allocator allocates a lot of space and does not free it. When
75
 * the frame allocator fails to allocate a frame, it calls slab_reclaim().
769 palkovsky 76
 * It tries 'light reclaim' first, then brutal reclaim. The light reclaim
77
 * releases slabs from cpu-shared magazine-list, until at least 1 slab
78
 * is deallocated in each cache (this algorithm should probably change).
79
 * The brutal reclaim removes all cached objects, even from CPU-bound
80
 * magazines.
81
 *
1248 jermar 82
 * TODO:@n
83
 * For better CPU-scaling the magazine allocation strategy should
775 palkovsky 84
 * be extended. Currently, if the cache does not have magazine, it asks
85
 * for non-cpu cached magazine cache to provide one. It might be feasible
86
 * to add cpu-cached magazine cache (which would allocate it's magazines
87
 * from non-cpu-cached mag. cache). This would provide a nice per-cpu
88
 * buffer. The other possibility is to use the per-cache
89
 * 'empty-magazine-list', which decreases competing for 1 per-system
90
 * magazine cache.
91
 *
1248 jermar 92
 * @li it might be good to add granularity of locks even to slab level,
93
 *     we could then try_spinlock over all partial slabs and thus improve
94
 *     scalability even on slab level
769 palkovsky 95
 */
96
 
759 palkovsky 97
#include <synch/spinlock.h>
98
#include <mm/slab.h>
788 jermar 99
#include <adt/list.h>
759 palkovsky 100
#include <memstr.h>
101
#include <align.h>
762 palkovsky 102
#include <mm/frame.h>
759 palkovsky 103
#include <config.h>
104
#include <print.h>
105
#include <arch.h>
106
#include <panic.h>
762 palkovsky 107
#include <debug.h>
771 palkovsky 108
#include <bitops.h>
759 palkovsky 109
 
110
SPINLOCK_INITIALIZE(slab_cache_lock);
769 palkovsky 111
static LIST_INITIALIZE(slab_cache_list);
759 palkovsky 112
 
769 palkovsky 113
/** Magazine cache */
114
static slab_cache_t mag_cache;
115
/** Cache for cache descriptors */
116
static slab_cache_t slab_cache_cache;
117
/** Cache for external slab descriptors
118
 * This time we want per-cpu cache, so do not make it static
1248 jermar 119
 * - using slab for internal slab structures will not deadlock,
769 palkovsky 120
 *   as all slab structures are 'small' - control structures of
121
 *   their caches do not require further allocation
122
 */
123
static slab_cache_t *slab_extern_cache;
771 palkovsky 124
/** Caches for malloc */
125
static slab_cache_t *malloc_caches[SLAB_MAX_MALLOC_W-SLAB_MIN_MALLOC_W+1];
126
char *malloc_names[] =  {
791 palkovsky 127
    "malloc-16","malloc-32","malloc-64","malloc-128",
771 palkovsky 128
    "malloc-256","malloc-512","malloc-1K","malloc-2K",
129
    "malloc-4K","malloc-8K","malloc-16K","malloc-32K",
1428 palkovsky 130
    "malloc-64K","malloc-128K","malloc-256K"
771 palkovsky 131
};
762 palkovsky 132
 
769 palkovsky 133
/** Slab descriptor */
762 palkovsky 134
typedef struct {
135
    slab_cache_t *cache; /**< Pointer to parent cache */
136
    link_t link;       /* List of full/partial slabs */
137
    void *start;       /**< Start address of first available item */
138
    count_t available; /**< Count of available items in this slab */
139
    index_t nextavail; /**< The index of next available item */
140
}slab_t;
141
 
791 palkovsky 142
#ifdef CONFIG_DEBUG
143
static int _slab_initialized = 0;
144
#endif
145
 
759 palkovsky 146
/**************************************/
1248 jermar 147
/* Slab allocation functions          */
759 palkovsky 148
 
762 palkovsky 149
/**
150
 * Allocate frames for slab space and initialize
151
 *
152
 */
153
static slab_t * slab_space_alloc(slab_cache_t *cache, int flags)
154
{
155
    void *data;
156
    slab_t *slab;
157
    size_t fsize;
158
    int i;
159
    int status;
814 palkovsky 160
    pfn_t pfn;
161
    int zone=0;
162
 
163
    pfn = frame_alloc_rc_zone(cache->order, FRAME_KA | flags, &status, &zone);
164
    data = (void *) PA2KA(PFN2ADDR(pfn));
764 palkovsky 165
    if (status != FRAME_OK) {
762 palkovsky 166
        return NULL;
764 palkovsky 167
    }
768 palkovsky 168
    if (! (cache->flags & SLAB_CACHE_SLINSIDE)) {
769 palkovsky 169
        slab = slab_alloc(slab_extern_cache, flags);
762 palkovsky 170
        if (!slab) {
814 palkovsky 171
            frame_free(ADDR2PFN(KA2PA(data)));
762 palkovsky 172
            return NULL;
173
        }
174
    } else {
175
        fsize = (PAGE_SIZE << cache->order);
176
        slab = data + fsize - sizeof(*slab);
177
    }
1288 jermar 178
 
762 palkovsky 179
    /* Fill in slab structures */
814 palkovsky 180
    for (i=0; i < (1 << cache->order); i++)
181
        frame_set_parent(pfn+i, slab, zone);
762 palkovsky 182
 
183
    slab->start = data;
184
    slab->available = cache->objects;
185
    slab->nextavail = 0;
767 palkovsky 186
    slab->cache = cache;
762 palkovsky 187
 
188
    for (i=0; i<cache->objects;i++)
189
        *((int *) (slab->start + i*cache->size)) = i+1;
764 palkovsky 190
 
191
    atomic_inc(&cache->allocated_slabs);
762 palkovsky 192
    return slab;
193
}
194
 
759 palkovsky 195
/**
1248 jermar 196
 * Deallocate space associated with slab
762 palkovsky 197
 *
198
 * @return number of freed frames
199
 */
200
static count_t slab_space_free(slab_cache_t *cache, slab_t *slab)
201
{
814 palkovsky 202
    frame_free(ADDR2PFN(KA2PA(slab->start)));
768 palkovsky 203
    if (! (cache->flags & SLAB_CACHE_SLINSIDE))
769 palkovsky 204
        slab_free(slab_extern_cache, slab);
764 palkovsky 205
 
206
    atomic_dec(&cache->allocated_slabs);
207
 
762 palkovsky 208
    return 1 << cache->order;
209
}
210
 
211
/** Map object to slab structure */
212
static slab_t * obj2slab(void *obj)
213
{
814 palkovsky 214
    return (slab_t *)frame_get_parent(ADDR2PFN(KA2PA(obj)), 0);
762 palkovsky 215
}
216
 
217
/**************************************/
1248 jermar 218
/* Slab functions */
762 palkovsky 219
 
220
 
221
/**
759 palkovsky 222
 * Return object to slab and call a destructor
223
 *
762 palkovsky 224
 * @param slab If the caller knows directly slab of the object, otherwise NULL
225
 *
759 palkovsky 226
 * @return Number of freed pages
227
 */
762 palkovsky 228
static count_t slab_obj_destroy(slab_cache_t *cache, void *obj,
229
                slab_t *slab)
759 palkovsky 230
{
787 palkovsky 231
    int freed = 0;
232
 
762 palkovsky 233
    if (!slab)
234
        slab = obj2slab(obj);
235
 
767 palkovsky 236
    ASSERT(slab->cache == cache);
237
 
787 palkovsky 238
    if (cache->destructor)
239
        freed = cache->destructor(obj);
240
 
776 palkovsky 241
    spinlock_lock(&cache->slablock);
789 palkovsky 242
    ASSERT(slab->available < cache->objects);
776 palkovsky 243
 
762 palkovsky 244
    *((int *)obj) = slab->nextavail;
245
    slab->nextavail = (obj - slab->start)/cache->size;
246
    slab->available++;
247
 
248
    /* Move it to correct list */
249
    if (slab->available == cache->objects) {
250
        /* Free associated memory */
251
        list_remove(&slab->link);
782 palkovsky 252
        spinlock_unlock(&cache->slablock);
253
 
787 palkovsky 254
        return freed + slab_space_free(cache, slab);
782 palkovsky 255
 
780 palkovsky 256
    } else if (slab->available == 1) {
257
        /* It was in full, move to partial */
258
        list_remove(&slab->link);
259
        list_prepend(&slab->link, &cache->partial_slabs);
762 palkovsky 260
    }
783 palkovsky 261
    spinlock_unlock(&cache->slablock);
787 palkovsky 262
    return freed;
759 palkovsky 263
}
264
 
265
/**
266
 * Take new object from slab or create new if needed
267
 *
268
 * @return Object address or null
269
 */
270
static void * slab_obj_create(slab_cache_t *cache, int flags)
271
{
762 palkovsky 272
    slab_t *slab;
273
    void *obj;
274
 
776 palkovsky 275
    spinlock_lock(&cache->slablock);
276
 
762 palkovsky 277
    if (list_empty(&cache->partial_slabs)) {
278
        /* Allow recursion and reclaiming
1248 jermar 279
         * - this should work, as the slab control structures
1288 jermar 280
         *   are small and do not need to allocate with anything
281
         *   other than frame_alloc when they are allocating,
762 palkovsky 282
         *   that's why we should get recursion at most 1-level deep
283
         */
776 palkovsky 284
        spinlock_unlock(&cache->slablock);
762 palkovsky 285
        slab = slab_space_alloc(cache, flags);
780 palkovsky 286
        if (!slab)
287
            return NULL;
776 palkovsky 288
        spinlock_lock(&cache->slablock);
762 palkovsky 289
    } else {
290
        slab = list_get_instance(cache->partial_slabs.next,
291
                     slab_t,
292
                     link);
293
        list_remove(&slab->link);
294
    }
295
    obj = slab->start + slab->nextavail * cache->size;
296
    slab->nextavail = *((int *)obj);
297
    slab->available--;
787 palkovsky 298
 
762 palkovsky 299
    if (! slab->available)
764 palkovsky 300
        list_prepend(&slab->link, &cache->full_slabs);
762 palkovsky 301
    else
764 palkovsky 302
        list_prepend(&slab->link, &cache->partial_slabs);
776 palkovsky 303
 
304
    spinlock_unlock(&cache->slablock);
787 palkovsky 305
 
306
    if (cache->constructor && cache->constructor(obj, flags)) {
307
        /* Bad, bad, construction failed */
308
        slab_obj_destroy(cache, obj, slab);
309
        return NULL;
310
    }
762 palkovsky 311
    return obj;
759 palkovsky 312
}
313
 
314
/**************************************/
315
/* CPU-Cache slab functions */
316
 
317
/**
781 palkovsky 318
 * Finds a full magazine in cache, takes it from list
319
 * and returns it
320
 *
321
 * @param first If true, return first, else last mag
322
 */
323
static slab_magazine_t * get_mag_from_cache(slab_cache_t *cache,
324
                        int first)
325
{
326
    slab_magazine_t *mag = NULL;
327
    link_t *cur;
328
 
329
    spinlock_lock(&cache->maglock);
330
    if (!list_empty(&cache->magazines)) {
331
        if (first)
332
            cur = cache->magazines.next;
333
        else
334
            cur = cache->magazines.prev;
335
        mag = list_get_instance(cur, slab_magazine_t, link);
336
        list_remove(&mag->link);
337
        atomic_dec(&cache->magazine_counter);
338
    }
339
    spinlock_unlock(&cache->maglock);
340
    return mag;
341
}
342
 
343
/** Prepend magazine to magazine list in cache */
344
static void put_mag_to_cache(slab_cache_t *cache, slab_magazine_t *mag)
345
{
346
    spinlock_lock(&cache->maglock);
347
 
348
    list_prepend(&mag->link, &cache->magazines);
349
    atomic_inc(&cache->magazine_counter);
350
 
351
    spinlock_unlock(&cache->maglock);
352
}
353
 
354
/**
759 palkovsky 355
 * Free all objects in magazine and free memory associated with magazine
356
 *
357
 * @return Number of freed pages
358
 */
359
static count_t magazine_destroy(slab_cache_t *cache,
360
                slab_magazine_t *mag)
361
{
362
    int i;
363
    count_t frames = 0;
364
 
767 palkovsky 365
    for (i=0;i < mag->busy; i++) {
762 palkovsky 366
        frames += slab_obj_destroy(cache, mag->objs[i], NULL);
767 palkovsky 367
        atomic_dec(&cache->cached_objs);
368
    }
759 palkovsky 369
 
370
    slab_free(&mag_cache, mag);
371
 
372
    return frames;
373
}
374
 
375
/**
769 palkovsky 376
 * Find full magazine, set it as current and return it
377
 *
378
 * Assume cpu_magazine lock is held
379
 */
380
static slab_magazine_t * get_full_current_mag(slab_cache_t *cache)
381
{
382
    slab_magazine_t *cmag, *lastmag, *newmag;
383
 
384
    cmag = cache->mag_cache[CPU->id].current;
385
    lastmag = cache->mag_cache[CPU->id].last;
386
    if (cmag) { /* First try local CPU magazines */
387
        if (cmag->busy)
388
            return cmag;
389
 
390
        if (lastmag && lastmag->busy) {
391
            cache->mag_cache[CPU->id].current = lastmag;
392
            cache->mag_cache[CPU->id].last = cmag;
393
            return lastmag;
394
        }
395
    }
396
    /* Local magazines are empty, import one from magazine list */
781 palkovsky 397
    newmag = get_mag_from_cache(cache, 1);
398
    if (!newmag)
769 palkovsky 399
        return NULL;
400
 
401
    if (lastmag)
781 palkovsky 402
        magazine_destroy(cache, lastmag);
403
 
769 palkovsky 404
    cache->mag_cache[CPU->id].last = cmag;
405
    cache->mag_cache[CPU->id].current = newmag;
406
    return newmag;
407
}
408
 
409
/**
759 palkovsky 410
 * Try to find object in CPU-cache magazines
411
 *
412
 * @return Pointer to object or NULL if not available
413
 */
414
static void * magazine_obj_get(slab_cache_t *cache)
415
{
416
    slab_magazine_t *mag;
767 palkovsky 417
    void *obj;
759 palkovsky 418
 
772 palkovsky 419
    if (!CPU)
420
        return NULL;
421
 
759 palkovsky 422
    spinlock_lock(&cache->mag_cache[CPU->id].lock);
423
 
769 palkovsky 424
    mag = get_full_current_mag(cache);
425
    if (!mag) {
426
        spinlock_unlock(&cache->mag_cache[CPU->id].lock);
427
        return NULL;
759 palkovsky 428
    }
767 palkovsky 429
    obj = mag->objs[--mag->busy];
759 palkovsky 430
    spinlock_unlock(&cache->mag_cache[CPU->id].lock);
767 palkovsky 431
    atomic_dec(&cache->cached_objs);
432
 
433
    return obj;
759 palkovsky 434
}
435
 
436
/**
768 palkovsky 437
 * Assure that the current magazine is empty, return pointer to it, or NULL if
769 palkovsky 438
 * no empty magazine is available and cannot be allocated
759 palkovsky 439
 *
773 palkovsky 440
 * Assume mag_cache[CPU->id].lock is held
441
 *
759 palkovsky 442
 * We have 2 magazines bound to processor.
443
 * First try the current.
444
 *  If full, try the last.
445
 *   If full, put to magazines list.
446
 *   allocate new, exchange last & current
447
 *
768 palkovsky 448
 */
449
static slab_magazine_t * make_empty_current_mag(slab_cache_t *cache)
450
{
451
    slab_magazine_t *cmag,*lastmag,*newmag;
452
 
453
    cmag = cache->mag_cache[CPU->id].current;
454
    lastmag = cache->mag_cache[CPU->id].last;
455
 
456
    if (cmag) {
457
        if (cmag->busy < cmag->size)
458
            return cmag;
459
        if (lastmag && lastmag->busy < lastmag->size) {
460
            cache->mag_cache[CPU->id].last = cmag;
461
            cache->mag_cache[CPU->id].current = lastmag;
462
            return lastmag;
463
        }
464
    }
465
    /* current | last are full | nonexistent, allocate new */
466
    /* We do not want to sleep just because of caching */
467
    /* Especially we do not want reclaiming to start, as
468
     * this would deadlock */
469
    newmag = slab_alloc(&mag_cache, FRAME_ATOMIC | FRAME_NO_RECLAIM);
470
    if (!newmag)
471
        return NULL;
472
    newmag->size = SLAB_MAG_SIZE;
473
    newmag->busy = 0;
474
 
475
    /* Flush last to magazine list */
781 palkovsky 476
    if (lastmag)
477
        put_mag_to_cache(cache, lastmag);
478
 
768 palkovsky 479
    /* Move current as last, save new as current */
480
    cache->mag_cache[CPU->id].last = cmag; 
481
    cache->mag_cache[CPU->id].current = newmag;
482
 
483
    return newmag;
484
}
485
 
486
/**
487
 * Put object into CPU-cache magazine
488
 *
759 palkovsky 489
 * @return 0 - success, -1 - could not get memory
490
 */
491
static int magazine_obj_put(slab_cache_t *cache, void *obj)
492
{
493
    slab_magazine_t *mag;
494
 
772 palkovsky 495
    if (!CPU)
496
        return -1;
497
 
759 palkovsky 498
    spinlock_lock(&cache->mag_cache[CPU->id].lock);
768 palkovsky 499
 
500
    mag = make_empty_current_mag(cache);
769 palkovsky 501
    if (!mag) {
502
        spinlock_unlock(&cache->mag_cache[CPU->id].lock);
503
        return -1;
504
    }
759 palkovsky 505
 
506
    mag->objs[mag->busy++] = obj;
507
 
508
    spinlock_unlock(&cache->mag_cache[CPU->id].lock);
767 palkovsky 509
    atomic_inc(&cache->cached_objs);
759 palkovsky 510
    return 0;
511
}
512
 
513
 
514
/**************************************/
1248 jermar 515
/* Slab cache functions */
759 palkovsky 516
 
762 palkovsky 517
/** Return number of objects that fit in certain cache size */
518
static int comp_objects(slab_cache_t *cache)
519
{
520
    if (cache->flags & SLAB_CACHE_SLINSIDE)
521
        return ((PAGE_SIZE << cache->order) - sizeof(slab_t)) / cache->size;
522
    else
523
        return (PAGE_SIZE << cache->order) / cache->size;
524
}
525
 
526
/** Return wasted space in slab */
527
static int badness(slab_cache_t *cache)
528
{
529
    int objects;
530
    int ssize;
531
 
532
    objects = comp_objects(cache);
533
    ssize = PAGE_SIZE << cache->order;
534
    if (cache->flags & SLAB_CACHE_SLINSIDE)
535
        ssize -= sizeof(slab_t);
536
    return ssize - objects*cache->size;
537
}
538
 
789 palkovsky 539
/**
540
 * Initialize mag_cache structure in slab cache
541
 */
542
static void make_magcache(slab_cache_t *cache)
543
{
544
    int i;
791 palkovsky 545
 
546
    ASSERT(_slab_initialized >= 2);
789 palkovsky 547
 
822 palkovsky 548
    cache->mag_cache = malloc(sizeof(slab_mag_cache_t)*config.cpu_count,0);
789 palkovsky 549
    for (i=0; i < config.cpu_count; i++) {
550
        memsetb((__address)&cache->mag_cache[i],
551
            sizeof(cache->mag_cache[i]), 0);
552
        spinlock_initialize(&cache->mag_cache[i].lock,
553
                    "slab_maglock_cpu");
554
    }
555
}
556
 
759 palkovsky 557
/** Initialize allocated memory as a slab cache */
558
static void
559
_slab_cache_create(slab_cache_t *cache,
560
           char *name,
561
           size_t size,
562
           size_t align,
563
           int (*constructor)(void *obj, int kmflag),
787 palkovsky 564
           int (*destructor)(void *obj),
759 palkovsky 565
           int flags)
566
{
771 palkovsky 567
    int pages;
783 palkovsky 568
    ipl_t ipl;
759 palkovsky 569
 
570
    memsetb((__address)cache, sizeof(*cache), 0);
571
    cache->name = name;
572
 
766 palkovsky 573
    if (align < sizeof(__native))
574
        align = sizeof(__native);
575
    size = ALIGN_UP(size, align);
576
 
762 palkovsky 577
    cache->size = size;
759 palkovsky 578
 
579
    cache->constructor = constructor;
580
    cache->destructor = destructor;
581
    cache->flags = flags;
582
 
583
    list_initialize(&cache->full_slabs);
584
    list_initialize(&cache->partial_slabs);
585
    list_initialize(&cache->magazines);
776 palkovsky 586
    spinlock_initialize(&cache->slablock, "slab_lock");
587
    spinlock_initialize(&cache->maglock, "slab_maglock");
789 palkovsky 588
    if (! (cache->flags & SLAB_CACHE_NOMAGAZINE))
589
        make_magcache(cache);
759 palkovsky 590
 
591
    /* Compute slab sizes, object counts in slabs etc. */
592
    if (cache->size < SLAB_INSIDE_SIZE)
593
        cache->flags |= SLAB_CACHE_SLINSIDE;
594
 
762 palkovsky 595
    /* Minimum slab order */
771 palkovsky 596
    pages = ((cache->size-1) >> PAGE_WIDTH) + 1;
1677 palkovsky 597
    /* We need the 2^order >= pages */
598
    if (pages == 1)
599
        cache->order = 0;
600
    else
601
        cache->order = fnzb(pages-1)+1;
766 palkovsky 602
 
762 palkovsky 603
    while (badness(cache) > SLAB_MAX_BADNESS(cache)) {
604
        cache->order += 1;
605
    }
606
    cache->objects = comp_objects(cache);
766 palkovsky 607
    /* If info fits in, put it inside */
608
    if (badness(cache) > sizeof(slab_t))
609
        cache->flags |= SLAB_CACHE_SLINSIDE;
762 palkovsky 610
 
783 palkovsky 611
    /* Add cache to cache list */
612
    ipl = interrupts_disable();
759 palkovsky 613
    spinlock_lock(&slab_cache_lock);
614
 
615
    list_append(&cache->link, &slab_cache_list);
616
 
617
    spinlock_unlock(&slab_cache_lock);
783 palkovsky 618
    interrupts_restore(ipl);
759 palkovsky 619
}
620
 
621
/** Create slab cache  */
622
slab_cache_t * slab_cache_create(char *name,
623
                 size_t size,
624
                 size_t align,
625
                 int (*constructor)(void *obj, int kmflag),
787 palkovsky 626
                 int (*destructor)(void *obj),
759 palkovsky 627
                 int flags)
628
{
629
    slab_cache_t *cache;
630
 
769 palkovsky 631
    cache = slab_alloc(&slab_cache_cache, 0);
759 palkovsky 632
    _slab_cache_create(cache, name, size, align, constructor, destructor,
633
               flags);
634
    return cache;
635
}
636
 
637
/**
638
 * Reclaim space occupied by objects that are already free
639
 *
640
 * @param flags If contains SLAB_RECLAIM_ALL, do aggressive freeing
641
 * @return Number of freed pages
642
 */
643
static count_t _slab_reclaim(slab_cache_t *cache, int flags)
644
{
645
    int i;
646
    slab_magazine_t *mag;
647
    count_t frames = 0;
781 palkovsky 648
    int magcount;
759 palkovsky 649
 
650
    if (cache->flags & SLAB_CACHE_NOMAGAZINE)
651
        return 0; /* Nothing to do */
781 palkovsky 652
 
653
    /* We count up to original magazine count to avoid
654
     * endless loop
655
     */
656
    magcount = atomic_get(&cache->magazine_counter);
657
    while (magcount-- && (mag=get_mag_from_cache(cache,0))) {
658
        frames += magazine_destroy(cache,mag);
659
        if (!(flags & SLAB_RECLAIM_ALL) && frames)
660
            break;
769 palkovsky 661
    }
759 palkovsky 662
 
663
    if (flags & SLAB_RECLAIM_ALL) {
781 palkovsky 664
        /* Free cpu-bound magazines */
759 palkovsky 665
        /* Destroy CPU magazines */
666
        for (i=0; i<config.cpu_count; i++) {
781 palkovsky 667
            spinlock_lock(&cache->mag_cache[i].lock);
668
 
759 palkovsky 669
            mag = cache->mag_cache[i].current;
670
            if (mag)
671
                frames += magazine_destroy(cache, mag);
672
            cache->mag_cache[i].current = NULL;
673
 
674
            mag = cache->mag_cache[i].last;
675
            if (mag)
676
                frames += magazine_destroy(cache, mag);
677
            cache->mag_cache[i].last = NULL;
781 palkovsky 678
 
679
            spinlock_unlock(&cache->mag_cache[i].lock);
759 palkovsky 680
        }
681
    }
767 palkovsky 682
 
759 palkovsky 683
    return frames;
684
}
685
 
686
/** Check that there are no slabs and remove cache from system  */
687
void slab_cache_destroy(slab_cache_t *cache)
688
{
781 palkovsky 689
    ipl_t ipl;
690
 
691
    /* First remove cache from link, so that we don't need
692
     * to disable interrupts later
693
     */
694
 
695
    ipl = interrupts_disable();
696
    spinlock_lock(&slab_cache_lock);
697
 
698
    list_remove(&cache->link);
699
 
700
    spinlock_unlock(&slab_cache_lock);
701
    interrupts_restore(ipl);
702
 
759 palkovsky 703
    /* Do not lock anything, we assume the software is correct and
704
     * does not touch the cache when it decides to destroy it */
705
 
706
    /* Destroy all magazines */
707
    _slab_reclaim(cache, SLAB_RECLAIM_ALL);
708
 
709
    /* All slabs must be empty */
710
    if (!list_empty(&cache->full_slabs) \
711
        || !list_empty(&cache->partial_slabs))
712
        panic("Destroying cache that is not empty.");
713
 
789 palkovsky 714
    if (!(cache->flags & SLAB_CACHE_NOMAGAZINE))
822 palkovsky 715
        free(cache->mag_cache);
769 palkovsky 716
    slab_free(&slab_cache_cache, cache);
759 palkovsky 717
}
718
 
719
/** Allocate new object from cache - if no flags given, always returns
720
    memory */
721
void * slab_alloc(slab_cache_t *cache, int flags)
722
{
723
    ipl_t ipl;
724
    void *result = NULL;
773 palkovsky 725
 
759 palkovsky 726
    /* Disable interrupts to avoid deadlocks with interrupt handlers */
727
    ipl = interrupts_disable();
771 palkovsky 728
 
814 palkovsky 729
    if (!(cache->flags & SLAB_CACHE_NOMAGAZINE)) {
759 palkovsky 730
        result = magazine_obj_get(cache);
814 palkovsky 731
    }
776 palkovsky 732
    if (!result)
759 palkovsky 733
        result = slab_obj_create(cache, flags);
734
 
769 palkovsky 735
    interrupts_restore(ipl);
736
 
764 palkovsky 737
    if (result)
738
        atomic_inc(&cache->allocated_objs);
739
 
759 palkovsky 740
    return result;
741
}
742
 
771 palkovsky 743
/** Return object to cache, use slab if known  */
744
static void _slab_free(slab_cache_t *cache, void *obj, slab_t *slab)
759 palkovsky 745
{
746
    ipl_t ipl;
747
 
748
    ipl = interrupts_disable();
749
 
762 palkovsky 750
    if ((cache->flags & SLAB_CACHE_NOMAGAZINE) \
751
        || magazine_obj_put(cache, obj)) {
776 palkovsky 752
 
771 palkovsky 753
        slab_obj_destroy(cache, obj, slab);
776 palkovsky 754
 
759 palkovsky 755
    }
769 palkovsky 756
    interrupts_restore(ipl);
764 palkovsky 757
    atomic_dec(&cache->allocated_objs);
759 palkovsky 758
}
759
 
771 palkovsky 760
/** Return slab object to cache */
761
void slab_free(slab_cache_t *cache, void *obj)
762
{
763
    _slab_free(cache,obj,NULL);
764
}
765
 
759 palkovsky 766
/* Go through all caches and reclaim what is possible */
767
count_t slab_reclaim(int flags)
768
{
769
    slab_cache_t *cache;
770
    link_t *cur;
771
    count_t frames = 0;
772
 
773
    spinlock_lock(&slab_cache_lock);
774
 
776 palkovsky 775
    /* TODO: Add assert, that interrupts are disabled, otherwise
776
     * memory allocation from interrupts can deadlock.
777
     */
778
 
759 palkovsky 779
    for (cur = slab_cache_list.next;cur!=&slab_cache_list; cur=cur->next) {
780
        cache = list_get_instance(cur, slab_cache_t, link);
781
        frames += _slab_reclaim(cache, flags);
782
    }
783
 
784
    spinlock_unlock(&slab_cache_lock);
785
 
786
    return frames;
787
}
788
 
789
 
790
/* Print list of slabs */
791
void slab_print_list(void)
792
{
793
    slab_cache_t *cache;
794
    link_t *cur;
783 palkovsky 795
    ipl_t ipl;
796
 
797
    ipl = interrupts_disable();
759 palkovsky 798
    spinlock_lock(&slab_cache_lock);
1248 jermar 799
    printf("slab name\t  Osize\t  Pages\t Obj/pg\t  Slabs\t Cached\tAllocobjs\tCtl\n");
759 palkovsky 800
    for (cur = slab_cache_list.next;cur!=&slab_cache_list; cur=cur->next) {
801
        cache = list_get_instance(cur, slab_cache_t, link);
1224 cejka 802
        printf("%s\t%7zd\t%7zd\t%7zd\t%7zd\t%7zd\t%7zd\t\t%s\n", cache->name, cache->size,
766 palkovsky 803
               (1 << cache->order), cache->objects,
767 palkovsky 804
               atomic_get(&cache->allocated_slabs),
805
               atomic_get(&cache->cached_objs),
766 palkovsky 806
               atomic_get(&cache->allocated_objs),
807
               cache->flags & SLAB_CACHE_SLINSIDE ? "In" : "Out");
759 palkovsky 808
    }
809
    spinlock_unlock(&slab_cache_lock);
783 palkovsky 810
    interrupts_restore(ipl);
759 palkovsky 811
}
812
 
813
void slab_cache_init(void)
814
{
771 palkovsky 815
    int i, size;
816
 
759 palkovsky 817
    /* Initialize magazine cache */
818
    _slab_cache_create(&mag_cache,
819
               "slab_magazine",
820
               sizeof(slab_magazine_t)+SLAB_MAG_SIZE*sizeof(void*),
821
               sizeof(__address),
822
               NULL, NULL,
769 palkovsky 823
               SLAB_CACHE_NOMAGAZINE | SLAB_CACHE_SLINSIDE);
824
    /* Initialize slab_cache cache */
825
    _slab_cache_create(&slab_cache_cache,
826
               "slab_cache",
789 palkovsky 827
               sizeof(slab_cache_cache),
769 palkovsky 828
               sizeof(__address),
829
               NULL, NULL,
830
               SLAB_CACHE_NOMAGAZINE | SLAB_CACHE_SLINSIDE);
831
    /* Initialize external slab cache */
832
    slab_extern_cache = slab_cache_create("slab_extern",
833
                          sizeof(slab_t),
834
                          0, NULL, NULL,
789 palkovsky 835
                          SLAB_CACHE_SLINSIDE | SLAB_CACHE_MAGDEFERRED);
759 palkovsky 836
 
837
    /* Initialize structures for malloc */
771 palkovsky 838
    for (i=0, size=(1<<SLAB_MIN_MALLOC_W);
839
         i < (SLAB_MAX_MALLOC_W-SLAB_MIN_MALLOC_W+1);
840
         i++, size <<= 1) {
841
        malloc_caches[i] = slab_cache_create(malloc_names[i],
842
                             size, 0,
789 palkovsky 843
                             NULL,NULL, SLAB_CACHE_MAGDEFERRED);
771 palkovsky 844
    }
778 palkovsky 845
#ifdef CONFIG_DEBUG       
846
    _slab_initialized = 1;
847
#endif
759 palkovsky 848
}
771 palkovsky 849
 
789 palkovsky 850
/** Enable cpu_cache
851
 *
852
 * Kernel calls this function, when it knows the real number of
853
 * processors.
854
 * Allocate slab for cpucache and enable it on all existing
855
 * slabs that are SLAB_CACHE_MAGDEFERRED
856
 */
857
void slab_enable_cpucache(void)
858
{
859
    link_t *cur;
860
    slab_cache_t *s;
861
 
791 palkovsky 862
#ifdef CONFIG_DEBUG
863
    _slab_initialized = 2;
864
#endif
865
 
789 palkovsky 866
    spinlock_lock(&slab_cache_lock);
867
 
868
    for (cur=slab_cache_list.next; cur != &slab_cache_list;cur=cur->next){
869
        s = list_get_instance(cur, slab_cache_t, link);
870
        if ((s->flags & SLAB_CACHE_MAGDEFERRED) != SLAB_CACHE_MAGDEFERRED)
871
            continue;
872
        make_magcache(s);
873
        s->flags &= ~SLAB_CACHE_MAGDEFERRED;
874
    }
875
 
876
    spinlock_unlock(&slab_cache_lock);
877
}
878
 
771 palkovsky 879
/**************************************/
880
/* kalloc/kfree functions             */
822 palkovsky 881
void * malloc(unsigned int size, int flags)
771 palkovsky 882
{
883
    int idx;
778 palkovsky 884
 
885
    ASSERT(_slab_initialized);
1288 jermar 886
    ASSERT(size && size <= (1 << SLAB_MAX_MALLOC_W));
771 palkovsky 887
 
888
    if (size < (1 << SLAB_MIN_MALLOC_W))
889
        size = (1 << SLAB_MIN_MALLOC_W);
890
 
891
    idx = fnzb(size-1) - SLAB_MIN_MALLOC_W + 1;
892
 
893
    return slab_alloc(malloc_caches[idx], flags);
894
}
895
 
822 palkovsky 896
void free(void *obj)
771 palkovsky 897
{
781 palkovsky 898
    slab_t *slab;
899
 
900
    if (!obj) return;
901
 
902
    slab = obj2slab(obj);
771 palkovsky 903
    _slab_free(slab->cache, obj, slab);
904
}