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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
    count_t frames = 0;
232
 
233
    if (!slab)
234
        slab = obj2slab(obj);
235
 
767 palkovsky 236
    ASSERT(slab->cache == cache);
780 palkovsky 237
    ASSERT(slab->available < cache->objects);
767 palkovsky 238
 
776 palkovsky 239
    spinlock_lock(&cache->slablock);
240
 
762 palkovsky 241
    *((int *)obj) = slab->nextavail;
242
    slab->nextavail = (obj - slab->start)/cache->size;
243
    slab->available++;
244
 
245
    /* Move it to correct list */
246
    if (slab->available == cache->objects) {
247
        /* Free associated memory */
248
        list_remove(&slab->link);
776 palkovsky 249
        /* This should not produce deadlock, as
250
         * magazine is always allocated with NO reclaim,
251
         * keep all locks */
762 palkovsky 252
        frames = slab_space_free(cache, slab);
780 palkovsky 253
    } else if (slab->available == 1) {
254
        /* It was in full, move to partial */
255
        list_remove(&slab->link);
256
        list_prepend(&slab->link, &cache->partial_slabs);
762 palkovsky 257
    }
258
 
776 palkovsky 259
    spinlock_unlock(&cache->slablock);
260
 
762 palkovsky 261
    return frames;
759 palkovsky 262
}
263
 
264
/**
265
 * Take new object from slab or create new if needed
266
 *
267
 * @return Object address or null
268
 */
269
static void * slab_obj_create(slab_cache_t *cache, int flags)
270
{
762 palkovsky 271
    slab_t *slab;
272
    void *obj;
273
 
776 palkovsky 274
    spinlock_lock(&cache->slablock);
275
 
762 palkovsky 276
    if (list_empty(&cache->partial_slabs)) {
277
        /* Allow recursion and reclaiming
278
         * - this should work, as the SLAB control structures
279
         *   are small and do not need to allocte with anything
280
         *   other ten frame_alloc when they are allocating,
281
         *   that's why we should get recursion at most 1-level deep
282
         */
776 palkovsky 283
        spinlock_unlock(&cache->slablock);
762 palkovsky 284
        slab = slab_space_alloc(cache, flags);
780 palkovsky 285
        if (!slab)
286
            return NULL;
776 palkovsky 287
        spinlock_lock(&cache->slablock);
762 palkovsky 288
    } else {
289
        slab = list_get_instance(cache->partial_slabs.next,
290
                     slab_t,
291
                     link);
292
        list_remove(&slab->link);
293
    }
294
    obj = slab->start + slab->nextavail * cache->size;
295
    slab->nextavail = *((int *)obj);
296
    slab->available--;
297
    if (! slab->available)
764 palkovsky 298
        list_prepend(&slab->link, &cache->full_slabs);
762 palkovsky 299
    else
764 palkovsky 300
        list_prepend(&slab->link, &cache->partial_slabs);
776 palkovsky 301
 
302
    spinlock_unlock(&cache->slablock);
762 palkovsky 303
    return obj;
759 palkovsky 304
}
305
 
306
/**************************************/
307
/* CPU-Cache slab functions */
308
 
309
/**
781 palkovsky 310
 * Finds a full magazine in cache, takes it from list
311
 * and returns it
312
 *
313
 * @param first If true, return first, else last mag
314
 */
315
static slab_magazine_t * get_mag_from_cache(slab_cache_t *cache,
316
                        int first)
317
{
318
    slab_magazine_t *mag = NULL;
319
    link_t *cur;
320
 
321
    spinlock_lock(&cache->maglock);
322
    if (!list_empty(&cache->magazines)) {
323
        if (first)
324
            cur = cache->magazines.next;
325
        else
326
            cur = cache->magazines.prev;
327
        mag = list_get_instance(cur, slab_magazine_t, link);
328
        list_remove(&mag->link);
329
        atomic_dec(&cache->magazine_counter);
330
    }
331
    spinlock_unlock(&cache->maglock);
332
    return mag;
333
}
334
 
335
/** Prepend magazine to magazine list in cache */
336
static void put_mag_to_cache(slab_cache_t *cache, slab_magazine_t *mag)
337
{
338
    spinlock_lock(&cache->maglock);
339
 
340
    list_prepend(&mag->link, &cache->magazines);
341
    atomic_inc(&cache->magazine_counter);
342
 
343
    spinlock_unlock(&cache->maglock);
344
}
345
 
346
/**
759 palkovsky 347
 * Free all objects in magazine and free memory associated with magazine
348
 *
349
 * @return Number of freed pages
350
 */
351
static count_t magazine_destroy(slab_cache_t *cache,
352
                slab_magazine_t *mag)
353
{
354
    int i;
355
    count_t frames = 0;
356
 
767 palkovsky 357
    for (i=0;i < mag->busy; i++) {
762 palkovsky 358
        frames += slab_obj_destroy(cache, mag->objs[i], NULL);
767 palkovsky 359
        atomic_dec(&cache->cached_objs);
360
    }
759 palkovsky 361
 
362
    slab_free(&mag_cache, mag);
363
 
364
    return frames;
365
}
366
 
367
/**
769 palkovsky 368
 * Find full magazine, set it as current and return it
369
 *
370
 * Assume cpu_magazine lock is held
371
 */
372
static slab_magazine_t * get_full_current_mag(slab_cache_t *cache)
373
{
374
    slab_magazine_t *cmag, *lastmag, *newmag;
375
 
376
    cmag = cache->mag_cache[CPU->id].current;
377
    lastmag = cache->mag_cache[CPU->id].last;
378
    if (cmag) { /* First try local CPU magazines */
379
        if (cmag->busy)
380
            return cmag;
381
 
382
        if (lastmag && lastmag->busy) {
383
            cache->mag_cache[CPU->id].current = lastmag;
384
            cache->mag_cache[CPU->id].last = cmag;
385
            return lastmag;
386
        }
387
    }
388
    /* Local magazines are empty, import one from magazine list */
781 palkovsky 389
    newmag = get_mag_from_cache(cache, 1);
390
    if (!newmag)
769 palkovsky 391
        return NULL;
392
 
393
    if (lastmag)
781 palkovsky 394
        magazine_destroy(cache, lastmag);
395
 
769 palkovsky 396
    cache->mag_cache[CPU->id].last = cmag;
397
    cache->mag_cache[CPU->id].current = newmag;
398
    return newmag;
399
}
400
 
401
/**
759 palkovsky 402
 * Try to find object in CPU-cache magazines
403
 *
404
 * @return Pointer to object or NULL if not available
405
 */
406
static void * magazine_obj_get(slab_cache_t *cache)
407
{
408
    slab_magazine_t *mag;
767 palkovsky 409
    void *obj;
759 palkovsky 410
 
772 palkovsky 411
    if (!CPU)
412
        return NULL;
413
 
759 palkovsky 414
    spinlock_lock(&cache->mag_cache[CPU->id].lock);
415
 
769 palkovsky 416
    mag = get_full_current_mag(cache);
417
    if (!mag) {
418
        spinlock_unlock(&cache->mag_cache[CPU->id].lock);
419
        return NULL;
759 palkovsky 420
    }
767 palkovsky 421
    obj = mag->objs[--mag->busy];
759 palkovsky 422
    spinlock_unlock(&cache->mag_cache[CPU->id].lock);
767 palkovsky 423
    atomic_dec(&cache->cached_objs);
424
 
425
    return obj;
759 palkovsky 426
}
427
 
428
/**
768 palkovsky 429
 * Assure that the current magazine is empty, return pointer to it, or NULL if
769 palkovsky 430
 * no empty magazine is available and cannot be allocated
759 palkovsky 431
 *
773 palkovsky 432
 * Assume mag_cache[CPU->id].lock is held
433
 *
759 palkovsky 434
 * We have 2 magazines bound to processor.
435
 * First try the current.
436
 *  If full, try the last.
437
 *   If full, put to magazines list.
438
 *   allocate new, exchange last & current
439
 *
768 palkovsky 440
 */
441
static slab_magazine_t * make_empty_current_mag(slab_cache_t *cache)
442
{
443
    slab_magazine_t *cmag,*lastmag,*newmag;
444
 
445
    cmag = cache->mag_cache[CPU->id].current;
446
    lastmag = cache->mag_cache[CPU->id].last;
447
 
448
    if (cmag) {
449
        if (cmag->busy < cmag->size)
450
            return cmag;
451
        if (lastmag && lastmag->busy < lastmag->size) {
452
            cache->mag_cache[CPU->id].last = cmag;
453
            cache->mag_cache[CPU->id].current = lastmag;
454
            return lastmag;
455
        }
456
    }
457
    /* current | last are full | nonexistent, allocate new */
458
    /* We do not want to sleep just because of caching */
459
    /* Especially we do not want reclaiming to start, as
460
     * this would deadlock */
461
    newmag = slab_alloc(&mag_cache, FRAME_ATOMIC | FRAME_NO_RECLAIM);
462
    if (!newmag)
463
        return NULL;
464
    newmag->size = SLAB_MAG_SIZE;
465
    newmag->busy = 0;
466
 
467
    /* Flush last to magazine list */
781 palkovsky 468
    if (lastmag)
469
        put_mag_to_cache(cache, lastmag);
470
 
768 palkovsky 471
    /* Move current as last, save new as current */
472
    cache->mag_cache[CPU->id].last = cmag; 
473
    cache->mag_cache[CPU->id].current = newmag;
474
 
475
    return newmag;
476
}
477
 
478
/**
479
 * Put object into CPU-cache magazine
480
 *
759 palkovsky 481
 * @return 0 - success, -1 - could not get memory
482
 */
483
static int magazine_obj_put(slab_cache_t *cache, void *obj)
484
{
485
    slab_magazine_t *mag;
486
 
772 palkovsky 487
    if (!CPU)
488
        return -1;
489
 
759 palkovsky 490
    spinlock_lock(&cache->mag_cache[CPU->id].lock);
768 palkovsky 491
 
492
    mag = make_empty_current_mag(cache);
769 palkovsky 493
    if (!mag) {
494
        spinlock_unlock(&cache->mag_cache[CPU->id].lock);
495
        return -1;
496
    }
759 palkovsky 497
 
498
    mag->objs[mag->busy++] = obj;
499
 
500
    spinlock_unlock(&cache->mag_cache[CPU->id].lock);
767 palkovsky 501
    atomic_inc(&cache->cached_objs);
759 palkovsky 502
    return 0;
503
}
504
 
505
 
506
/**************************************/
762 palkovsky 507
/* SLAB CACHE functions */
759 palkovsky 508
 
762 palkovsky 509
/** Return number of objects that fit in certain cache size */
510
static int comp_objects(slab_cache_t *cache)
511
{
512
    if (cache->flags & SLAB_CACHE_SLINSIDE)
513
        return ((PAGE_SIZE << cache->order) - sizeof(slab_t)) / cache->size;
514
    else
515
        return (PAGE_SIZE << cache->order) / cache->size;
516
}
517
 
518
/** Return wasted space in slab */
519
static int badness(slab_cache_t *cache)
520
{
521
    int objects;
522
    int ssize;
523
 
524
    objects = comp_objects(cache);
525
    ssize = PAGE_SIZE << cache->order;
526
    if (cache->flags & SLAB_CACHE_SLINSIDE)
527
        ssize -= sizeof(slab_t);
528
    return ssize - objects*cache->size;
529
}
530
 
759 palkovsky 531
/** Initialize allocated memory as a slab cache */
532
static void
533
_slab_cache_create(slab_cache_t *cache,
534
           char *name,
535
           size_t size,
536
           size_t align,
537
           int (*constructor)(void *obj, int kmflag),
538
           void (*destructor)(void *obj),
539
           int flags)
540
{
541
    int i;
771 palkovsky 542
    int pages;
759 palkovsky 543
 
544
    memsetb((__address)cache, sizeof(*cache), 0);
545
    cache->name = name;
546
 
766 palkovsky 547
    if (align < sizeof(__native))
548
        align = sizeof(__native);
549
    size = ALIGN_UP(size, align);
550
 
762 palkovsky 551
    cache->size = size;
759 palkovsky 552
 
553
    cache->constructor = constructor;
554
    cache->destructor = destructor;
555
    cache->flags = flags;
556
 
557
    list_initialize(&cache->full_slabs);
558
    list_initialize(&cache->partial_slabs);
559
    list_initialize(&cache->magazines);
776 palkovsky 560
    spinlock_initialize(&cache->slablock, "slab_lock");
561
    spinlock_initialize(&cache->maglock, "slab_maglock");
768 palkovsky 562
    if (! (cache->flags & SLAB_CACHE_NOMAGAZINE)) {
773 palkovsky 563
        for (i=0; i < config.cpu_count; i++) {
772 palkovsky 564
            memsetb((__address)&cache->mag_cache[i],
565
                sizeof(cache->mag_cache[i]), 0);
759 palkovsky 566
            spinlock_initialize(&cache->mag_cache[i].lock,
776 palkovsky 567
                        "slab_maglock_cpu");
772 palkovsky 568
        }
759 palkovsky 569
    }
570
 
571
    /* Compute slab sizes, object counts in slabs etc. */
572
    if (cache->size < SLAB_INSIDE_SIZE)
573
        cache->flags |= SLAB_CACHE_SLINSIDE;
574
 
762 palkovsky 575
    /* Minimum slab order */
771 palkovsky 576
    pages = ((cache->size-1) >> PAGE_WIDTH) + 1;
577
    cache->order = fnzb(pages);
766 palkovsky 578
 
762 palkovsky 579
    while (badness(cache) > SLAB_MAX_BADNESS(cache)) {
580
        cache->order += 1;
581
    }
582
    cache->objects = comp_objects(cache);
766 palkovsky 583
    /* If info fits in, put it inside */
584
    if (badness(cache) > sizeof(slab_t))
585
        cache->flags |= SLAB_CACHE_SLINSIDE;
762 palkovsky 586
 
759 palkovsky 587
    spinlock_lock(&slab_cache_lock);
588
 
589
    list_append(&cache->link, &slab_cache_list);
590
 
591
    spinlock_unlock(&slab_cache_lock);
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.
781 palkovsky 747
     * - cache_destroy can call this with interrupts enabled :-/
776 palkovsky 748
     */
749
 
759 palkovsky 750
    for (cur = slab_cache_list.next;cur!=&slab_cache_list; cur=cur->next) {
751
        cache = list_get_instance(cur, slab_cache_t, link);
752
        frames += _slab_reclaim(cache, flags);
753
    }
754
 
755
    spinlock_unlock(&slab_cache_lock);
756
 
757
    return frames;
758
}
759
 
760
 
761
/* Print list of slabs */
762
void slab_print_list(void)
763
{
764
    slab_cache_t *cache;
765
    link_t *cur;
766
 
767
    spinlock_lock(&slab_cache_lock);
767 palkovsky 768
    printf("SLAB name\tOsize\tPages\tObj/pg\tSlabs\tCached\tAllocobjs\tCtl\n");
759 palkovsky 769
    for (cur = slab_cache_list.next;cur!=&slab_cache_list; cur=cur->next) {
770
        cache = list_get_instance(cur, slab_cache_t, link);
767 palkovsky 771
        printf("%s\t%d\t%d\t%d\t%d\t%d\t%d\t\t%s\n", cache->name, cache->size,
766 palkovsky 772
               (1 << cache->order), cache->objects,
767 palkovsky 773
               atomic_get(&cache->allocated_slabs),
774
               atomic_get(&cache->cached_objs),
766 palkovsky 775
               atomic_get(&cache->allocated_objs),
776
               cache->flags & SLAB_CACHE_SLINSIDE ? "In" : "Out");
759 palkovsky 777
    }
778
    spinlock_unlock(&slab_cache_lock);
779
}
780
 
778 palkovsky 781
#ifdef CONFIG_DEBUG
782
static int _slab_initialized = 0;
783
#endif
784
 
759 palkovsky 785
void slab_cache_init(void)
786
{
771 palkovsky 787
    int i, size;
788
 
759 palkovsky 789
    /* Initialize magazine cache */
790
    _slab_cache_create(&mag_cache,
791
               "slab_magazine",
792
               sizeof(slab_magazine_t)+SLAB_MAG_SIZE*sizeof(void*),
793
               sizeof(__address),
794
               NULL, NULL,
769 palkovsky 795
               SLAB_CACHE_NOMAGAZINE | SLAB_CACHE_SLINSIDE);
796
    /* Initialize slab_cache cache */
797
    _slab_cache_create(&slab_cache_cache,
798
               "slab_cache",
799
               sizeof(slab_cache_cache) + config.cpu_count*sizeof(slab_cache_cache.mag_cache[0]),
800
               sizeof(__address),
801
               NULL, NULL,
802
               SLAB_CACHE_NOMAGAZINE | SLAB_CACHE_SLINSIDE);
803
    /* Initialize external slab cache */
804
    slab_extern_cache = slab_cache_create("slab_extern",
805
                          sizeof(slab_t),
806
                          0, NULL, NULL,
807
                          SLAB_CACHE_SLINSIDE);
759 palkovsky 808
 
809
    /* Initialize structures for malloc */
771 palkovsky 810
    for (i=0, size=(1<<SLAB_MIN_MALLOC_W);
811
         i < (SLAB_MAX_MALLOC_W-SLAB_MIN_MALLOC_W+1);
812
         i++, size <<= 1) {
813
        malloc_caches[i] = slab_cache_create(malloc_names[i],
814
                             size, 0,
815
                             NULL,NULL,0);
816
    }
778 palkovsky 817
#ifdef CONFIG_DEBUG       
818
    _slab_initialized = 1;
819
#endif
759 palkovsky 820
}
771 palkovsky 821
 
822
/**************************************/
823
/* kalloc/kfree functions             */
824
void * kalloc(unsigned int size, int flags)
825
{
826
    int idx;
778 palkovsky 827
 
828
    ASSERT(_slab_initialized);
771 palkovsky 829
    ASSERT( size && size <= (1 << SLAB_MAX_MALLOC_W));
830
 
831
    if (size < (1 << SLAB_MIN_MALLOC_W))
832
        size = (1 << SLAB_MIN_MALLOC_W);
833
 
834
    idx = fnzb(size-1) - SLAB_MIN_MALLOC_W + 1;
835
 
836
    return slab_alloc(malloc_caches[idx], flags);
837
}
838
 
839
 
840
void kfree(void *obj)
841
{
781 palkovsky 842
    slab_t *slab;
843
 
844
    if (!obj) return;
845
 
846
    slab = obj2slab(obj);
771 palkovsky 847
    _slab_free(slab->cache, obj, slab);
848
}