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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
/*
30
 * The SLAB allocator is closely modelled after Opensolaris SLAB allocator
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
42
 *     supported, but we would need to adjust allocating strategy)
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>
96
#include <list.h>
97
#include <memstr.h>
98
#include <align.h>
99
#include <mm/heap.h>
762 palkovsky 100
#include <mm/frame.h>
759 palkovsky 101
#include <config.h>
102
#include <print.h>
103
#include <arch.h>
104
#include <panic.h>
762 palkovsky 105
#include <debug.h>
771 palkovsky 106
#include <bitops.h>
759 palkovsky 107
 
108
SPINLOCK_INITIALIZE(slab_cache_lock);
769 palkovsky 109
static LIST_INITIALIZE(slab_cache_list);
759 palkovsky 110
 
769 palkovsky 111
/** Magazine cache */
112
static slab_cache_t mag_cache;
113
/** Cache for cache descriptors */
114
static slab_cache_t slab_cache_cache;
759 palkovsky 115
 
769 palkovsky 116
/** Cache for external slab descriptors
117
 * This time we want per-cpu cache, so do not make it static
118
 * - using SLAB for internal SLAB structures will not deadlock,
119
 *   as all slab structures are 'small' - control structures of
120
 *   their caches do not require further allocation
121
 */
122
static slab_cache_t *slab_extern_cache;
771 palkovsky 123
/** Caches for malloc */
124
static slab_cache_t *malloc_caches[SLAB_MAX_MALLOC_W-SLAB_MIN_MALLOC_W+1];
125
char *malloc_names[] =  {
126
    "malloc-8","malloc-16","malloc-32","malloc-64","malloc-128",
127
    "malloc-256","malloc-512","malloc-1K","malloc-2K",
128
    "malloc-4K","malloc-8K","malloc-16K","malloc-32K",
129
    "malloc-64K","malloc-128K"
130
};
762 palkovsky 131
 
769 palkovsky 132
/** Slab descriptor */
762 palkovsky 133
typedef struct {
134
    slab_cache_t *cache; /**< Pointer to parent cache */
135
    link_t link;       /* List of full/partial slabs */
136
    void *start;       /**< Start address of first available item */
137
    count_t available; /**< Count of available items in this slab */
138
    index_t nextavail; /**< The index of next available item */
139
}slab_t;
140
 
759 palkovsky 141
/**************************************/
762 palkovsky 142
/* SLAB allocation functions          */
759 palkovsky 143
 
762 palkovsky 144
/**
145
 * Allocate frames for slab space and initialize
146
 *
147
 */
148
static slab_t * slab_space_alloc(slab_cache_t *cache, int flags)
149
{
150
    void *data;
151
    slab_t *slab;
152
    size_t fsize;
153
    int i;
154
    zone_t *zone = NULL;
155
    int status;
764 palkovsky 156
    frame_t *frame;
759 palkovsky 157
 
762 palkovsky 158
    data = (void *)frame_alloc(FRAME_KA | flags, cache->order, &status, &zone);
764 palkovsky 159
    if (status != FRAME_OK) {
762 palkovsky 160
        return NULL;
764 palkovsky 161
    }
768 palkovsky 162
    if (! (cache->flags & SLAB_CACHE_SLINSIDE)) {
769 palkovsky 163
        slab = slab_alloc(slab_extern_cache, flags);
762 palkovsky 164
        if (!slab) {
165
            frame_free((__address)data);
166
            return NULL;
167
        }
168
    } else {
169
        fsize = (PAGE_SIZE << cache->order);
170
        slab = data + fsize - sizeof(*slab);
171
    }
764 palkovsky 172
 
762 palkovsky 173
    /* Fill in slab structures */
763 jermar 174
    /* TODO: some better way of accessing the frame */
766 palkovsky 175
    for (i=0; i < (1 << cache->order); i++) {
764 palkovsky 176
        frame = ADDR2FRAME(zone, KA2PA((__address)(data+i*PAGE_SIZE)));
177
        frame->parent = slab;
762 palkovsky 178
    }
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
{
199
    frame_free((__address)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
{
211
    frame_t *frame;
212
 
213
    frame = frame_addr2frame((__address)obj);
214
    return (slab_t *)frame->parent;
215
}
216
 
217
/**************************************/
218
/* SLAB functions */
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
{
762 palkovsky 231
    if (!slab)
232
        slab = obj2slab(obj);
233
 
767 palkovsky 234
    ASSERT(slab->cache == cache);
780 palkovsky 235
    ASSERT(slab->available < cache->objects);
767 palkovsky 236
 
776 palkovsky 237
    spinlock_lock(&cache->slablock);
238
 
762 palkovsky 239
    *((int *)obj) = slab->nextavail;
240
    slab->nextavail = (obj - slab->start)/cache->size;
241
    slab->available++;
242
 
243
    /* Move it to correct list */
244
    if (slab->available == cache->objects) {
245
        /* Free associated memory */
246
        list_remove(&slab->link);
782 palkovsky 247
        spinlock_unlock(&cache->slablock);
248
 
249
        return slab_space_free(cache, slab);
250
 
780 palkovsky 251
    } else if (slab->available == 1) {
252
        /* It was in full, move to partial */
253
        list_remove(&slab->link);
254
        list_prepend(&slab->link, &cache->partial_slabs);
762 palkovsky 255
    }
783 palkovsky 256
    spinlock_unlock(&cache->slablock);
782 palkovsky 257
    return 0;
759 palkovsky 258
}
259
 
260
/**
261
 * Take new object from slab or create new if needed
262
 *
263
 * @return Object address or null
264
 */
265
static void * slab_obj_create(slab_cache_t *cache, int flags)
266
{
762 palkovsky 267
    slab_t *slab;
268
    void *obj;
269
 
776 palkovsky 270
    spinlock_lock(&cache->slablock);
271
 
762 palkovsky 272
    if (list_empty(&cache->partial_slabs)) {
273
        /* Allow recursion and reclaiming
274
         * - this should work, as the SLAB control structures
275
         *   are small and do not need to allocte with anything
276
         *   other ten frame_alloc when they are allocating,
277
         *   that's why we should get recursion at most 1-level deep
278
         */
776 palkovsky 279
        spinlock_unlock(&cache->slablock);
762 palkovsky 280
        slab = slab_space_alloc(cache, flags);
780 palkovsky 281
        if (!slab)
282
            return NULL;
776 palkovsky 283
        spinlock_lock(&cache->slablock);
762 palkovsky 284
    } else {
285
        slab = list_get_instance(cache->partial_slabs.next,
286
                     slab_t,
287
                     link);
288
        list_remove(&slab->link);
289
    }
290
    obj = slab->start + slab->nextavail * cache->size;
291
    slab->nextavail = *((int *)obj);
292
    slab->available--;
293
    if (! slab->available)
764 palkovsky 294
        list_prepend(&slab->link, &cache->full_slabs);
762 palkovsky 295
    else
764 palkovsky 296
        list_prepend(&slab->link, &cache->partial_slabs);
776 palkovsky 297
 
298
    spinlock_unlock(&cache->slablock);
762 palkovsky 299
    return obj;
759 palkovsky 300
}
301
 
302
/**************************************/
303
/* CPU-Cache slab functions */
304
 
305
/**
781 palkovsky 306
 * Finds a full magazine in cache, takes it from list
307
 * and returns it
308
 *
309
 * @param first If true, return first, else last mag
310
 */
311
static slab_magazine_t * get_mag_from_cache(slab_cache_t *cache,
312
                        int first)
313
{
314
    slab_magazine_t *mag = NULL;
315
    link_t *cur;
316
 
317
    spinlock_lock(&cache->maglock);
318
    if (!list_empty(&cache->magazines)) {
319
        if (first)
320
            cur = cache->magazines.next;
321
        else
322
            cur = cache->magazines.prev;
323
        mag = list_get_instance(cur, slab_magazine_t, link);
324
        list_remove(&mag->link);
325
        atomic_dec(&cache->magazine_counter);
326
    }
327
    spinlock_unlock(&cache->maglock);
328
    return mag;
329
}
330
 
331
/** Prepend magazine to magazine list in cache */
332
static void put_mag_to_cache(slab_cache_t *cache, slab_magazine_t *mag)
333
{
334
    spinlock_lock(&cache->maglock);
335
 
336
    list_prepend(&mag->link, &cache->magazines);
337
    atomic_inc(&cache->magazine_counter);
338
 
339
    spinlock_unlock(&cache->maglock);
340
}
341
 
342
/**
759 palkovsky 343
 * Free all objects in magazine and free memory associated with magazine
344
 *
345
 * @return Number of freed pages
346
 */
347
static count_t magazine_destroy(slab_cache_t *cache,
348
                slab_magazine_t *mag)
349
{
350
    int i;
351
    count_t frames = 0;
352
 
767 palkovsky 353
    for (i=0;i < mag->busy; i++) {
762 palkovsky 354
        frames += slab_obj_destroy(cache, mag->objs[i], NULL);
767 palkovsky 355
        atomic_dec(&cache->cached_objs);
356
    }
759 palkovsky 357
 
358
    slab_free(&mag_cache, mag);
359
 
360
    return frames;
361
}
362
 
363
/**
769 palkovsky 364
 * Find full magazine, set it as current and return it
365
 *
366
 * Assume cpu_magazine lock is held
367
 */
368
static slab_magazine_t * get_full_current_mag(slab_cache_t *cache)
369
{
370
    slab_magazine_t *cmag, *lastmag, *newmag;
371
 
372
    cmag = cache->mag_cache[CPU->id].current;
373
    lastmag = cache->mag_cache[CPU->id].last;
374
    if (cmag) { /* First try local CPU magazines */
375
        if (cmag->busy)
376
            return cmag;
377
 
378
        if (lastmag && lastmag->busy) {
379
            cache->mag_cache[CPU->id].current = lastmag;
380
            cache->mag_cache[CPU->id].last = cmag;
381
            return lastmag;
382
        }
383
    }
384
    /* Local magazines are empty, import one from magazine list */
781 palkovsky 385
    newmag = get_mag_from_cache(cache, 1);
386
    if (!newmag)
769 palkovsky 387
        return NULL;
388
 
389
    if (lastmag)
781 palkovsky 390
        magazine_destroy(cache, lastmag);
391
 
769 palkovsky 392
    cache->mag_cache[CPU->id].last = cmag;
393
    cache->mag_cache[CPU->id].current = newmag;
394
    return newmag;
395
}
396
 
397
/**
759 palkovsky 398
 * Try to find object in CPU-cache magazines
399
 *
400
 * @return Pointer to object or NULL if not available
401
 */
402
static void * magazine_obj_get(slab_cache_t *cache)
403
{
404
    slab_magazine_t *mag;
767 palkovsky 405
    void *obj;
759 palkovsky 406
 
772 palkovsky 407
    if (!CPU)
408
        return NULL;
409
 
759 palkovsky 410
    spinlock_lock(&cache->mag_cache[CPU->id].lock);
411
 
769 palkovsky 412
    mag = get_full_current_mag(cache);
413
    if (!mag) {
414
        spinlock_unlock(&cache->mag_cache[CPU->id].lock);
415
        return NULL;
759 palkovsky 416
    }
767 palkovsky 417
    obj = mag->objs[--mag->busy];
759 palkovsky 418
    spinlock_unlock(&cache->mag_cache[CPU->id].lock);
767 palkovsky 419
    atomic_dec(&cache->cached_objs);
420
 
421
    return obj;
759 palkovsky 422
}
423
 
424
/**
768 palkovsky 425
 * Assure that the current magazine is empty, return pointer to it, or NULL if
769 palkovsky 426
 * no empty magazine is available and cannot be allocated
759 palkovsky 427
 *
773 palkovsky 428
 * Assume mag_cache[CPU->id].lock is held
429
 *
759 palkovsky 430
 * We have 2 magazines bound to processor.
431
 * First try the current.
432
 *  If full, try the last.
433
 *   If full, put to magazines list.
434
 *   allocate new, exchange last & current
435
 *
768 palkovsky 436
 */
437
static slab_magazine_t * make_empty_current_mag(slab_cache_t *cache)
438
{
439
    slab_magazine_t *cmag,*lastmag,*newmag;
440
 
441
    cmag = cache->mag_cache[CPU->id].current;
442
    lastmag = cache->mag_cache[CPU->id].last;
443
 
444
    if (cmag) {
445
        if (cmag->busy < cmag->size)
446
            return cmag;
447
        if (lastmag && lastmag->busy < lastmag->size) {
448
            cache->mag_cache[CPU->id].last = cmag;
449
            cache->mag_cache[CPU->id].current = lastmag;
450
            return lastmag;
451
        }
452
    }
453
    /* current | last are full | nonexistent, allocate new */
454
    /* We do not want to sleep just because of caching */
455
    /* Especially we do not want reclaiming to start, as
456
     * this would deadlock */
457
    newmag = slab_alloc(&mag_cache, FRAME_ATOMIC | FRAME_NO_RECLAIM);
458
    if (!newmag)
459
        return NULL;
460
    newmag->size = SLAB_MAG_SIZE;
461
    newmag->busy = 0;
462
 
463
    /* Flush last to magazine list */
781 palkovsky 464
    if (lastmag)
465
        put_mag_to_cache(cache, lastmag);
466
 
768 palkovsky 467
    /* Move current as last, save new as current */
468
    cache->mag_cache[CPU->id].last = cmag; 
469
    cache->mag_cache[CPU->id].current = newmag;
470
 
471
    return newmag;
472
}
473
 
474
/**
475
 * Put object into CPU-cache magazine
476
 *
759 palkovsky 477
 * @return 0 - success, -1 - could not get memory
478
 */
479
static int magazine_obj_put(slab_cache_t *cache, void *obj)
480
{
481
    slab_magazine_t *mag;
482
 
772 palkovsky 483
    if (!CPU)
484
        return -1;
485
 
759 palkovsky 486
    spinlock_lock(&cache->mag_cache[CPU->id].lock);
768 palkovsky 487
 
488
    mag = make_empty_current_mag(cache);
769 palkovsky 489
    if (!mag) {
490
        spinlock_unlock(&cache->mag_cache[CPU->id].lock);
491
        return -1;
492
    }
759 palkovsky 493
 
494
    mag->objs[mag->busy++] = obj;
495
 
496
    spinlock_unlock(&cache->mag_cache[CPU->id].lock);
767 palkovsky 497
    atomic_inc(&cache->cached_objs);
759 palkovsky 498
    return 0;
499
}
500
 
501
 
502
/**************************************/
762 palkovsky 503
/* SLAB CACHE functions */
759 palkovsky 504
 
762 palkovsky 505
/** Return number of objects that fit in certain cache size */
506
static int comp_objects(slab_cache_t *cache)
507
{
508
    if (cache->flags & SLAB_CACHE_SLINSIDE)
509
        return ((PAGE_SIZE << cache->order) - sizeof(slab_t)) / cache->size;
510
    else
511
        return (PAGE_SIZE << cache->order) / cache->size;
512
}
513
 
514
/** Return wasted space in slab */
515
static int badness(slab_cache_t *cache)
516
{
517
    int objects;
518
    int ssize;
519
 
520
    objects = comp_objects(cache);
521
    ssize = PAGE_SIZE << cache->order;
522
    if (cache->flags & SLAB_CACHE_SLINSIDE)
523
        ssize -= sizeof(slab_t);
524
    return ssize - objects*cache->size;
525
}
526
 
759 palkovsky 527
/** Initialize allocated memory as a slab cache */
528
static void
529
_slab_cache_create(slab_cache_t *cache,
530
           char *name,
531
           size_t size,
532
           size_t align,
533
           int (*constructor)(void *obj, int kmflag),
534
           void (*destructor)(void *obj),
535
           int flags)
536
{
537
    int i;
771 palkovsky 538
    int pages;
783 palkovsky 539
    ipl_t ipl;
759 palkovsky 540
 
541
    memsetb((__address)cache, sizeof(*cache), 0);
542
    cache->name = name;
543
 
766 palkovsky 544
    if (align < sizeof(__native))
545
        align = sizeof(__native);
546
    size = ALIGN_UP(size, align);
547
 
762 palkovsky 548
    cache->size = size;
759 palkovsky 549
 
550
    cache->constructor = constructor;
551
    cache->destructor = destructor;
552
    cache->flags = flags;
553
 
554
    list_initialize(&cache->full_slabs);
555
    list_initialize(&cache->partial_slabs);
556
    list_initialize(&cache->magazines);
776 palkovsky 557
    spinlock_initialize(&cache->slablock, "slab_lock");
558
    spinlock_initialize(&cache->maglock, "slab_maglock");
768 palkovsky 559
    if (! (cache->flags & SLAB_CACHE_NOMAGAZINE)) {
773 palkovsky 560
        for (i=0; i < config.cpu_count; i++) {
772 palkovsky 561
            memsetb((__address)&cache->mag_cache[i],
562
                sizeof(cache->mag_cache[i]), 0);
759 palkovsky 563
            spinlock_initialize(&cache->mag_cache[i].lock,
776 palkovsky 564
                        "slab_maglock_cpu");
772 palkovsky 565
        }
759 palkovsky 566
    }
567
 
568
    /* Compute slab sizes, object counts in slabs etc. */
569
    if (cache->size < SLAB_INSIDE_SIZE)
570
        cache->flags |= SLAB_CACHE_SLINSIDE;
571
 
762 palkovsky 572
    /* Minimum slab order */
771 palkovsky 573
    pages = ((cache->size-1) >> PAGE_WIDTH) + 1;
574
    cache->order = fnzb(pages);
766 palkovsky 575
 
762 palkovsky 576
    while (badness(cache) > SLAB_MAX_BADNESS(cache)) {
577
        cache->order += 1;
578
    }
579
    cache->objects = comp_objects(cache);
766 palkovsky 580
    /* If info fits in, put it inside */
581
    if (badness(cache) > sizeof(slab_t))
582
        cache->flags |= SLAB_CACHE_SLINSIDE;
762 palkovsky 583
 
783 palkovsky 584
    /* Add cache to cache list */
585
    ipl = interrupts_disable();
759 palkovsky 586
    spinlock_lock(&slab_cache_lock);
587
 
588
    list_append(&cache->link, &slab_cache_list);
589
 
590
    spinlock_unlock(&slab_cache_lock);
783 palkovsky 591
    interrupts_restore(ipl);
759 palkovsky 592
}
593
 
594
/** Create slab cache  */
595
slab_cache_t * slab_cache_create(char *name,
596
                 size_t size,
597
                 size_t align,
598
                 int (*constructor)(void *obj, int kmflag),
599
                 void (*destructor)(void *obj),
600
                 int flags)
601
{
602
    slab_cache_t *cache;
603
 
769 palkovsky 604
    cache = slab_alloc(&slab_cache_cache, 0);
759 palkovsky 605
    _slab_cache_create(cache, name, size, align, constructor, destructor,
606
               flags);
607
    return cache;
608
}
609
 
610
/**
611
 * Reclaim space occupied by objects that are already free
612
 *
613
 * @param flags If contains SLAB_RECLAIM_ALL, do aggressive freeing
614
 * @return Number of freed pages
615
 */
616
static count_t _slab_reclaim(slab_cache_t *cache, int flags)
617
{
618
    int i;
619
    slab_magazine_t *mag;
620
    count_t frames = 0;
781 palkovsky 621
    int magcount;
759 palkovsky 622
 
623
    if (cache->flags & SLAB_CACHE_NOMAGAZINE)
624
        return 0; /* Nothing to do */
781 palkovsky 625
 
626
    /* We count up to original magazine count to avoid
627
     * endless loop
628
     */
629
    magcount = atomic_get(&cache->magazine_counter);
630
    while (magcount-- && (mag=get_mag_from_cache(cache,0))) {
631
        frames += magazine_destroy(cache,mag);
632
        if (!(flags & SLAB_RECLAIM_ALL) && frames)
633
            break;
769 palkovsky 634
    }
759 palkovsky 635
 
636
    if (flags & SLAB_RECLAIM_ALL) {
781 palkovsky 637
        /* Free cpu-bound magazines */
759 palkovsky 638
        /* Destroy CPU magazines */
639
        for (i=0; i<config.cpu_count; i++) {
781 palkovsky 640
            spinlock_lock(&cache->mag_cache[i].lock);
641
 
759 palkovsky 642
            mag = cache->mag_cache[i].current;
643
            if (mag)
644
                frames += magazine_destroy(cache, mag);
645
            cache->mag_cache[i].current = NULL;
646
 
647
            mag = cache->mag_cache[i].last;
648
            if (mag)
649
                frames += magazine_destroy(cache, mag);
650
            cache->mag_cache[i].last = NULL;
781 palkovsky 651
 
652
            spinlock_unlock(&cache->mag_cache[i].lock);
759 palkovsky 653
        }
654
    }
767 palkovsky 655
 
759 palkovsky 656
    return frames;
657
}
658
 
659
/** Check that there are no slabs and remove cache from system  */
660
void slab_cache_destroy(slab_cache_t *cache)
661
{
781 palkovsky 662
    ipl_t ipl;
663
 
664
    /* First remove cache from link, so that we don't need
665
     * to disable interrupts later
666
     */
667
 
668
    ipl = interrupts_disable();
669
    spinlock_lock(&slab_cache_lock);
670
 
671
    list_remove(&cache->link);
672
 
673
    spinlock_unlock(&slab_cache_lock);
674
    interrupts_restore(ipl);
675
 
759 palkovsky 676
    /* Do not lock anything, we assume the software is correct and
677
     * does not touch the cache when it decides to destroy it */
678
 
679
    /* Destroy all magazines */
680
    _slab_reclaim(cache, SLAB_RECLAIM_ALL);
681
 
682
    /* All slabs must be empty */
683
    if (!list_empty(&cache->full_slabs) \
684
        || !list_empty(&cache->partial_slabs))
685
        panic("Destroying cache that is not empty.");
686
 
769 palkovsky 687
    slab_free(&slab_cache_cache, cache);
759 palkovsky 688
}
689
 
690
/** Allocate new object from cache - if no flags given, always returns
691
    memory */
692
void * slab_alloc(slab_cache_t *cache, int flags)
693
{
694
    ipl_t ipl;
695
    void *result = NULL;
773 palkovsky 696
 
759 palkovsky 697
    /* Disable interrupts to avoid deadlocks with interrupt handlers */
698
    ipl = interrupts_disable();
771 palkovsky 699
 
772 palkovsky 700
    if (!(cache->flags & SLAB_CACHE_NOMAGAZINE))
759 palkovsky 701
        result = magazine_obj_get(cache);
776 palkovsky 702
    if (!result)
759 palkovsky 703
        result = slab_obj_create(cache, flags);
704
 
769 palkovsky 705
    interrupts_restore(ipl);
706
 
764 palkovsky 707
    if (result)
708
        atomic_inc(&cache->allocated_objs);
709
 
759 palkovsky 710
    return result;
711
}
712
 
771 palkovsky 713
/** Return object to cache, use slab if known  */
714
static void _slab_free(slab_cache_t *cache, void *obj, slab_t *slab)
759 palkovsky 715
{
716
    ipl_t ipl;
717
 
718
    ipl = interrupts_disable();
719
 
762 palkovsky 720
    if ((cache->flags & SLAB_CACHE_NOMAGAZINE) \
721
        || magazine_obj_put(cache, obj)) {
776 palkovsky 722
 
771 palkovsky 723
        slab_obj_destroy(cache, obj, slab);
776 palkovsky 724
 
759 palkovsky 725
    }
769 palkovsky 726
    interrupts_restore(ipl);
764 palkovsky 727
    atomic_dec(&cache->allocated_objs);
759 palkovsky 728
}
729
 
771 palkovsky 730
/** Return slab object to cache */
731
void slab_free(slab_cache_t *cache, void *obj)
732
{
733
    _slab_free(cache,obj,NULL);
734
}
735
 
759 palkovsky 736
/* Go through all caches and reclaim what is possible */
737
count_t slab_reclaim(int flags)
738
{
739
    slab_cache_t *cache;
740
    link_t *cur;
741
    count_t frames = 0;
742
 
743
    spinlock_lock(&slab_cache_lock);
744
 
776 palkovsky 745
    /* TODO: Add assert, that interrupts are disabled, otherwise
746
     * memory allocation from interrupts can deadlock.
747
     */
748
 
759 palkovsky 749
    for (cur = slab_cache_list.next;cur!=&slab_cache_list; cur=cur->next) {
750
        cache = list_get_instance(cur, slab_cache_t, link);
751
        frames += _slab_reclaim(cache, flags);
752
    }
753
 
754
    spinlock_unlock(&slab_cache_lock);
755
 
756
    return frames;
757
}
758
 
759
 
760
/* Print list of slabs */
761
void slab_print_list(void)
762
{
763
    slab_cache_t *cache;
764
    link_t *cur;
783 palkovsky 765
    ipl_t ipl;
766
 
767
    ipl = interrupts_disable();
759 palkovsky 768
    spinlock_lock(&slab_cache_lock);
767 palkovsky 769
    printf("SLAB name\tOsize\tPages\tObj/pg\tSlabs\tCached\tAllocobjs\tCtl\n");
759 palkovsky 770
    for (cur = slab_cache_list.next;cur!=&slab_cache_list; cur=cur->next) {
771
        cache = list_get_instance(cur, slab_cache_t, link);
767 palkovsky 772
        printf("%s\t%d\t%d\t%d\t%d\t%d\t%d\t\t%s\n", cache->name, cache->size,
766 palkovsky 773
               (1 << cache->order), cache->objects,
767 palkovsky 774
               atomic_get(&cache->allocated_slabs),
775
               atomic_get(&cache->cached_objs),
766 palkovsky 776
               atomic_get(&cache->allocated_objs),
777
               cache->flags & SLAB_CACHE_SLINSIDE ? "In" : "Out");
759 palkovsky 778
    }
779
    spinlock_unlock(&slab_cache_lock);
783 palkovsky 780
    interrupts_restore(ipl);
759 palkovsky 781
}
782
 
778 palkovsky 783
#ifdef CONFIG_DEBUG
784
static int _slab_initialized = 0;
785
#endif
786
 
759 palkovsky 787
void slab_cache_init(void)
788
{
771 palkovsky 789
    int i, size;
790
 
759 palkovsky 791
    /* Initialize magazine cache */
792
    _slab_cache_create(&mag_cache,
793
               "slab_magazine",
794
               sizeof(slab_magazine_t)+SLAB_MAG_SIZE*sizeof(void*),
795
               sizeof(__address),
796
               NULL, NULL,
769 palkovsky 797
               SLAB_CACHE_NOMAGAZINE | SLAB_CACHE_SLINSIDE);
798
    /* Initialize slab_cache cache */
799
    _slab_cache_create(&slab_cache_cache,
800
               "slab_cache",
801
               sizeof(slab_cache_cache) + config.cpu_count*sizeof(slab_cache_cache.mag_cache[0]),
802
               sizeof(__address),
803
               NULL, NULL,
804
               SLAB_CACHE_NOMAGAZINE | SLAB_CACHE_SLINSIDE);
805
    /* Initialize external slab cache */
806
    slab_extern_cache = slab_cache_create("slab_extern",
807
                          sizeof(slab_t),
808
                          0, NULL, NULL,
809
                          SLAB_CACHE_SLINSIDE);
759 palkovsky 810
 
811
    /* Initialize structures for malloc */
771 palkovsky 812
    for (i=0, size=(1<<SLAB_MIN_MALLOC_W);
813
         i < (SLAB_MAX_MALLOC_W-SLAB_MIN_MALLOC_W+1);
814
         i++, size <<= 1) {
815
        malloc_caches[i] = slab_cache_create(malloc_names[i],
816
                             size, 0,
817
                             NULL,NULL,0);
818
    }
778 palkovsky 819
#ifdef CONFIG_DEBUG       
820
    _slab_initialized = 1;
821
#endif
759 palkovsky 822
}
771 palkovsky 823
 
824
/**************************************/
825
/* kalloc/kfree functions             */
826
void * kalloc(unsigned int size, int flags)
827
{
828
    int idx;
778 palkovsky 829
 
830
    ASSERT(_slab_initialized);
771 palkovsky 831
    ASSERT( size && size <= (1 << SLAB_MAX_MALLOC_W));
832
 
833
    if (size < (1 << SLAB_MIN_MALLOC_W))
834
        size = (1 << SLAB_MIN_MALLOC_W);
835
 
836
    idx = fnzb(size-1) - SLAB_MIN_MALLOC_W + 1;
837
 
838
    return slab_alloc(malloc_caches[idx], flags);
839
}
840
 
841
 
842
void kfree(void *obj)
843
{
781 palkovsky 844
    slab_t *slab;
845
 
846
    if (!obj) return;
847
 
848
    slab = obj2slab(obj);
771 palkovsky 849
    _slab_free(slab->cache, obj, slab);
850
}