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759 palkovsky 1
/*
2
 * Copyright (C) 2006 Ondrej Palkovsky
3
 * All rights reserved.
4
 *
5
 * Redistribution and use in source and binary forms, with or without
6
 * modification, are permitted provided that the following conditions
7
 * are met:
8
 *
9
 * - Redistributions of source code must retain the above copyright
10
 *   notice, this list of conditions and the following disclaimer.
11
 * - Redistributions in binary form must reproduce the above copyright
12
 *   notice, this list of conditions and the following disclaimer in the
13
 *   documentation and/or other materials provided with the distribution.
14
 * - The name of the author may not be used to endorse or promote products
15
 *   derived from this software without specific prior written permission.
16
 *
17
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
 */
28
 
769 palkovsky 29
/*
785 jermar 30
 * The SLAB allocator is closely modelled after OpenSolaris SLAB allocator
769 palkovsky 31
 * http://www.usenix.org/events/usenix01/full_papers/bonwick/bonwick_html/
32
 *
33
 * with the following exceptions:
34
 *   - empty SLABS are deallocated immediately
35
 *     (in Linux they are kept in linked list, in Solaris ???)
36
 *   - empty magazines are deallocated when not needed
37
 *     (in Solaris they are held in linked list in slab cache)
38
 *
39
 *   Following features are not currently supported but would be easy to do:
40
 *   - cache coloring
41
 *   - dynamic magazine growing (different magazine sizes are already
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>
788 jermar 96
#include <adt/list.h>
759 palkovsky 97
#include <memstr.h>
98
#include <align.h>
762 palkovsky 99
#include <mm/frame.h>
759 palkovsky 100
#include <config.h>
101
#include <print.h>
102
#include <arch.h>
103
#include <panic.h>
762 palkovsky 104
#include <debug.h>
771 palkovsky 105
#include <bitops.h>
759 palkovsky 106
 
107
SPINLOCK_INITIALIZE(slab_cache_lock);
769 palkovsky 108
static LIST_INITIALIZE(slab_cache_list);
759 palkovsky 109
 
769 palkovsky 110
/** Magazine cache */
111
static slab_cache_t mag_cache;
112
/** Cache for cache descriptors */
113
static slab_cache_t slab_cache_cache;
114
/** Cache for external slab descriptors
115
 * This time we want per-cpu cache, so do not make it static
116
 * - using SLAB for internal SLAB structures will not deadlock,
117
 *   as all slab structures are 'small' - control structures of
118
 *   their caches do not require further allocation
119
 */
120
static slab_cache_t *slab_extern_cache;
771 palkovsky 121
/** Caches for malloc */
122
static slab_cache_t *malloc_caches[SLAB_MAX_MALLOC_W-SLAB_MIN_MALLOC_W+1];
123
char *malloc_names[] =  {
791 palkovsky 124
    "malloc-16","malloc-32","malloc-64","malloc-128",
771 palkovsky 125
    "malloc-256","malloc-512","malloc-1K","malloc-2K",
126
    "malloc-4K","malloc-8K","malloc-16K","malloc-32K",
127
    "malloc-64K","malloc-128K"
128
};
762 palkovsky 129
 
769 palkovsky 130
/** Slab descriptor */
762 palkovsky 131
typedef struct {
132
    slab_cache_t *cache; /**< Pointer to parent cache */
133
    link_t link;       /* List of full/partial slabs */
134
    void *start;       /**< Start address of first available item */
135
    count_t available; /**< Count of available items in this slab */
136
    index_t nextavail; /**< The index of next available item */
137
}slab_t;
138
 
791 palkovsky 139
#ifdef CONFIG_DEBUG
140
static int _slab_initialized = 0;
141
#endif
142
 
759 palkovsky 143
/**************************************/
762 palkovsky 144
/* SLAB allocation functions          */
759 palkovsky 145
 
762 palkovsky 146
/**
147
 * Allocate frames for slab space and initialize
148
 *
149
 */
150
static slab_t * slab_space_alloc(slab_cache_t *cache, int flags)
151
{
152
    void *data;
153
    slab_t *slab;
154
    size_t fsize;
155
    int i;
156
    int status;
814 palkovsky 157
    pfn_t pfn;
158
    int zone=0;
159
 
160
    pfn = frame_alloc_rc_zone(cache->order, FRAME_KA | flags, &status, &zone);
161
    data = (void *) PA2KA(PFN2ADDR(pfn));
764 palkovsky 162
    if (status != FRAME_OK) {
762 palkovsky 163
        return NULL;
764 palkovsky 164
    }
768 palkovsky 165
    if (! (cache->flags & SLAB_CACHE_SLINSIDE)) {
769 palkovsky 166
        slab = slab_alloc(slab_extern_cache, flags);
762 palkovsky 167
        if (!slab) {
814 palkovsky 168
            frame_free(ADDR2PFN(KA2PA(data)));
762 palkovsky 169
            return NULL;
170
        }
171
    } else {
172
        fsize = (PAGE_SIZE << cache->order);
173
        slab = data + fsize - sizeof(*slab);
174
    }
764 palkovsky 175
 
762 palkovsky 176
    /* Fill in slab structures */
814 palkovsky 177
    for (i=0; i < (1 << cache->order); i++)
178
        frame_set_parent(pfn+i, slab, zone);
762 palkovsky 179
 
180
    slab->start = data;
181
    slab->available = cache->objects;
182
    slab->nextavail = 0;
767 palkovsky 183
    slab->cache = cache;
762 palkovsky 184
 
185
    for (i=0; i<cache->objects;i++)
186
        *((int *) (slab->start + i*cache->size)) = i+1;
764 palkovsky 187
 
188
    atomic_inc(&cache->allocated_slabs);
762 palkovsky 189
    return slab;
190
}
191
 
759 palkovsky 192
/**
766 palkovsky 193
 * Deallocate space associated with SLAB
762 palkovsky 194
 *
195
 * @return number of freed frames
196
 */
197
static count_t slab_space_free(slab_cache_t *cache, slab_t *slab)
198
{
814 palkovsky 199
    frame_free(ADDR2PFN(KA2PA(slab->start)));
768 palkovsky 200
    if (! (cache->flags & SLAB_CACHE_SLINSIDE))
769 palkovsky 201
        slab_free(slab_extern_cache, slab);
764 palkovsky 202
 
203
    atomic_dec(&cache->allocated_slabs);
204
 
762 palkovsky 205
    return 1 << cache->order;
206
}
207
 
208
/** Map object to slab structure */
209
static slab_t * obj2slab(void *obj)
210
{
814 palkovsky 211
    return (slab_t *)frame_get_parent(ADDR2PFN(KA2PA(obj)), 0);
762 palkovsky 212
}
213
 
214
/**************************************/
215
/* SLAB functions */
216
 
217
 
218
/**
759 palkovsky 219
 * Return object to slab and call a destructor
220
 *
762 palkovsky 221
 * @param slab If the caller knows directly slab of the object, otherwise NULL
222
 *
759 palkovsky 223
 * @return Number of freed pages
224
 */
762 palkovsky 225
static count_t slab_obj_destroy(slab_cache_t *cache, void *obj,
226
                slab_t *slab)
759 palkovsky 227
{
787 palkovsky 228
    int freed = 0;
229
 
762 palkovsky 230
    if (!slab)
231
        slab = obj2slab(obj);
232
 
767 palkovsky 233
    ASSERT(slab->cache == cache);
234
 
787 palkovsky 235
    if (cache->destructor)
236
        freed = cache->destructor(obj);
237
 
776 palkovsky 238
    spinlock_lock(&cache->slablock);
789 palkovsky 239
    ASSERT(slab->available < cache->objects);
776 palkovsky 240
 
762 palkovsky 241
    *((int *)obj) = slab->nextavail;
242
    slab->nextavail = (obj - slab->start)/cache->size;
243
    slab->available++;
244
 
245
    /* Move it to correct list */
246
    if (slab->available == cache->objects) {
247
        /* Free associated memory */
248
        list_remove(&slab->link);
782 palkovsky 249
        spinlock_unlock(&cache->slablock);
250
 
787 palkovsky 251
        return freed + slab_space_free(cache, slab);
782 palkovsky 252
 
780 palkovsky 253
    } else if (slab->available == 1) {
254
        /* It was in full, move to partial */
255
        list_remove(&slab->link);
256
        list_prepend(&slab->link, &cache->partial_slabs);
762 palkovsky 257
    }
783 palkovsky 258
    spinlock_unlock(&cache->slablock);
787 palkovsky 259
    return freed;
759 palkovsky 260
}
261
 
262
/**
263
 * Take new object from slab or create new if needed
264
 *
265
 * @return Object address or null
266
 */
267
static void * slab_obj_create(slab_cache_t *cache, int flags)
268
{
762 palkovsky 269
    slab_t *slab;
270
    void *obj;
271
 
776 palkovsky 272
    spinlock_lock(&cache->slablock);
273
 
762 palkovsky 274
    if (list_empty(&cache->partial_slabs)) {
275
        /* Allow recursion and reclaiming
276
         * - this should work, as the SLAB control structures
277
         *   are small and do not need to allocte with anything
278
         *   other ten frame_alloc when they are allocating,
279
         *   that's why we should get recursion at most 1-level deep
280
         */
776 palkovsky 281
        spinlock_unlock(&cache->slablock);
762 palkovsky 282
        slab = slab_space_alloc(cache, flags);
780 palkovsky 283
        if (!slab)
284
            return NULL;
776 palkovsky 285
        spinlock_lock(&cache->slablock);
762 palkovsky 286
    } else {
287
        slab = list_get_instance(cache->partial_slabs.next,
288
                     slab_t,
289
                     link);
290
        list_remove(&slab->link);
291
    }
292
    obj = slab->start + slab->nextavail * cache->size;
293
    slab->nextavail = *((int *)obj);
294
    slab->available--;
787 palkovsky 295
 
762 palkovsky 296
    if (! slab->available)
764 palkovsky 297
        list_prepend(&slab->link, &cache->full_slabs);
762 palkovsky 298
    else
764 palkovsky 299
        list_prepend(&slab->link, &cache->partial_slabs);
776 palkovsky 300
 
301
    spinlock_unlock(&cache->slablock);
787 palkovsky 302
 
303
    if (cache->constructor && cache->constructor(obj, flags)) {
304
        /* Bad, bad, construction failed */
305
        slab_obj_destroy(cache, obj, slab);
306
        return NULL;
307
    }
762 palkovsky 308
    return obj;
759 palkovsky 309
}
310
 
311
/**************************************/
312
/* CPU-Cache slab functions */
313
 
314
/**
781 palkovsky 315
 * Finds a full magazine in cache, takes it from list
316
 * and returns it
317
 *
318
 * @param first If true, return first, else last mag
319
 */
320
static slab_magazine_t * get_mag_from_cache(slab_cache_t *cache,
321
                        int first)
322
{
323
    slab_magazine_t *mag = NULL;
324
    link_t *cur;
325
 
326
    spinlock_lock(&cache->maglock);
327
    if (!list_empty(&cache->magazines)) {
328
        if (first)
329
            cur = cache->magazines.next;
330
        else
331
            cur = cache->magazines.prev;
332
        mag = list_get_instance(cur, slab_magazine_t, link);
333
        list_remove(&mag->link);
334
        atomic_dec(&cache->magazine_counter);
335
    }
336
    spinlock_unlock(&cache->maglock);
337
    return mag;
338
}
339
 
340
/** Prepend magazine to magazine list in cache */
341
static void put_mag_to_cache(slab_cache_t *cache, slab_magazine_t *mag)
342
{
343
    spinlock_lock(&cache->maglock);
344
 
345
    list_prepend(&mag->link, &cache->magazines);
346
    atomic_inc(&cache->magazine_counter);
347
 
348
    spinlock_unlock(&cache->maglock);
349
}
350
 
351
/**
759 palkovsky 352
 * Free all objects in magazine and free memory associated with magazine
353
 *
354
 * @return Number of freed pages
355
 */
356
static count_t magazine_destroy(slab_cache_t *cache,
357
                slab_magazine_t *mag)
358
{
359
    int i;
360
    count_t frames = 0;
361
 
767 palkovsky 362
    for (i=0;i < mag->busy; i++) {
762 palkovsky 363
        frames += slab_obj_destroy(cache, mag->objs[i], NULL);
767 palkovsky 364
        atomic_dec(&cache->cached_objs);
365
    }
759 palkovsky 366
 
367
    slab_free(&mag_cache, mag);
368
 
369
    return frames;
370
}
371
 
372
/**
769 palkovsky 373
 * Find full magazine, set it as current and return it
374
 *
375
 * Assume cpu_magazine lock is held
376
 */
377
static slab_magazine_t * get_full_current_mag(slab_cache_t *cache)
378
{
379
    slab_magazine_t *cmag, *lastmag, *newmag;
380
 
381
    cmag = cache->mag_cache[CPU->id].current;
382
    lastmag = cache->mag_cache[CPU->id].last;
383
    if (cmag) { /* First try local CPU magazines */
384
        if (cmag->busy)
385
            return cmag;
386
 
387
        if (lastmag && lastmag->busy) {
388
            cache->mag_cache[CPU->id].current = lastmag;
389
            cache->mag_cache[CPU->id].last = cmag;
390
            return lastmag;
391
        }
392
    }
393
    /* Local magazines are empty, import one from magazine list */
781 palkovsky 394
    newmag = get_mag_from_cache(cache, 1);
395
    if (!newmag)
769 palkovsky 396
        return NULL;
397
 
398
    if (lastmag)
781 palkovsky 399
        magazine_destroy(cache, lastmag);
400
 
769 palkovsky 401
    cache->mag_cache[CPU->id].last = cmag;
402
    cache->mag_cache[CPU->id].current = newmag;
403
    return newmag;
404
}
405
 
406
/**
759 palkovsky 407
 * Try to find object in CPU-cache magazines
408
 *
409
 * @return Pointer to object or NULL if not available
410
 */
411
static void * magazine_obj_get(slab_cache_t *cache)
412
{
413
    slab_magazine_t *mag;
767 palkovsky 414
    void *obj;
759 palkovsky 415
 
772 palkovsky 416
    if (!CPU)
417
        return NULL;
418
 
759 palkovsky 419
    spinlock_lock(&cache->mag_cache[CPU->id].lock);
420
 
769 palkovsky 421
    mag = get_full_current_mag(cache);
422
    if (!mag) {
423
        spinlock_unlock(&cache->mag_cache[CPU->id].lock);
424
        return NULL;
759 palkovsky 425
    }
767 palkovsky 426
    obj = mag->objs[--mag->busy];
759 palkovsky 427
    spinlock_unlock(&cache->mag_cache[CPU->id].lock);
767 palkovsky 428
    atomic_dec(&cache->cached_objs);
429
 
430
    return obj;
759 palkovsky 431
}
432
 
433
/**
768 palkovsky 434
 * Assure that the current magazine is empty, return pointer to it, or NULL if
769 palkovsky 435
 * no empty magazine is available and cannot be allocated
759 palkovsky 436
 *
773 palkovsky 437
 * Assume mag_cache[CPU->id].lock is held
438
 *
759 palkovsky 439
 * We have 2 magazines bound to processor.
440
 * First try the current.
441
 *  If full, try the last.
442
 *   If full, put to magazines list.
443
 *   allocate new, exchange last & current
444
 *
768 palkovsky 445
 */
446
static slab_magazine_t * make_empty_current_mag(slab_cache_t *cache)
447
{
448
    slab_magazine_t *cmag,*lastmag,*newmag;
449
 
450
    cmag = cache->mag_cache[CPU->id].current;
451
    lastmag = cache->mag_cache[CPU->id].last;
452
 
453
    if (cmag) {
454
        if (cmag->busy < cmag->size)
455
            return cmag;
456
        if (lastmag && lastmag->busy < lastmag->size) {
457
            cache->mag_cache[CPU->id].last = cmag;
458
            cache->mag_cache[CPU->id].current = lastmag;
459
            return lastmag;
460
        }
461
    }
462
    /* current | last are full | nonexistent, allocate new */
463
    /* We do not want to sleep just because of caching */
464
    /* Especially we do not want reclaiming to start, as
465
     * this would deadlock */
466
    newmag = slab_alloc(&mag_cache, FRAME_ATOMIC | FRAME_NO_RECLAIM);
467
    if (!newmag)
468
        return NULL;
469
    newmag->size = SLAB_MAG_SIZE;
470
    newmag->busy = 0;
471
 
472
    /* Flush last to magazine list */
781 palkovsky 473
    if (lastmag)
474
        put_mag_to_cache(cache, lastmag);
475
 
768 palkovsky 476
    /* Move current as last, save new as current */
477
    cache->mag_cache[CPU->id].last = cmag; 
478
    cache->mag_cache[CPU->id].current = newmag;
479
 
480
    return newmag;
481
}
482
 
483
/**
484
 * Put object into CPU-cache magazine
485
 *
759 palkovsky 486
 * @return 0 - success, -1 - could not get memory
487
 */
488
static int magazine_obj_put(slab_cache_t *cache, void *obj)
489
{
490
    slab_magazine_t *mag;
491
 
772 palkovsky 492
    if (!CPU)
493
        return -1;
494
 
759 palkovsky 495
    spinlock_lock(&cache->mag_cache[CPU->id].lock);
768 palkovsky 496
 
497
    mag = make_empty_current_mag(cache);
769 palkovsky 498
    if (!mag) {
499
        spinlock_unlock(&cache->mag_cache[CPU->id].lock);
500
        return -1;
501
    }
759 palkovsky 502
 
503
    mag->objs[mag->busy++] = obj;
504
 
505
    spinlock_unlock(&cache->mag_cache[CPU->id].lock);
767 palkovsky 506
    atomic_inc(&cache->cached_objs);
759 palkovsky 507
    return 0;
508
}
509
 
510
 
511
/**************************************/
762 palkovsky 512
/* SLAB CACHE functions */
759 palkovsky 513
 
762 palkovsky 514
/** Return number of objects that fit in certain cache size */
515
static int comp_objects(slab_cache_t *cache)
516
{
517
    if (cache->flags & SLAB_CACHE_SLINSIDE)
518
        return ((PAGE_SIZE << cache->order) - sizeof(slab_t)) / cache->size;
519
    else
520
        return (PAGE_SIZE << cache->order) / cache->size;
521
}
522
 
523
/** Return wasted space in slab */
524
static int badness(slab_cache_t *cache)
525
{
526
    int objects;
527
    int ssize;
528
 
529
    objects = comp_objects(cache);
530
    ssize = PAGE_SIZE << cache->order;
531
    if (cache->flags & SLAB_CACHE_SLINSIDE)
532
        ssize -= sizeof(slab_t);
533
    return ssize - objects*cache->size;
534
}
535
 
789 palkovsky 536
/**
537
 * Initialize mag_cache structure in slab cache
538
 */
539
static void make_magcache(slab_cache_t *cache)
540
{
541
    int i;
791 palkovsky 542
 
543
    ASSERT(_slab_initialized >= 2);
789 palkovsky 544
 
791 palkovsky 545
    cache->mag_cache = kalloc(sizeof(slab_mag_cache_t)*config.cpu_count,0);
789 palkovsky 546
    for (i=0; i < config.cpu_count; i++) {
547
        memsetb((__address)&cache->mag_cache[i],
548
            sizeof(cache->mag_cache[i]), 0);
549
        spinlock_initialize(&cache->mag_cache[i].lock,
550
                    "slab_maglock_cpu");
551
    }
552
}
553
 
759 palkovsky 554
/** Initialize allocated memory as a slab cache */
555
static void
556
_slab_cache_create(slab_cache_t *cache,
557
           char *name,
558
           size_t size,
559
           size_t align,
560
           int (*constructor)(void *obj, int kmflag),
787 palkovsky 561
           int (*destructor)(void *obj),
759 palkovsky 562
           int flags)
563
{
771 palkovsky 564
    int pages;
783 palkovsky 565
    ipl_t ipl;
759 palkovsky 566
 
567
    memsetb((__address)cache, sizeof(*cache), 0);
568
    cache->name = name;
569
 
766 palkovsky 570
    if (align < sizeof(__native))
571
        align = sizeof(__native);
572
    size = ALIGN_UP(size, align);
573
 
762 palkovsky 574
    cache->size = size;
759 palkovsky 575
 
576
    cache->constructor = constructor;
577
    cache->destructor = destructor;
578
    cache->flags = flags;
579
 
580
    list_initialize(&cache->full_slabs);
581
    list_initialize(&cache->partial_slabs);
582
    list_initialize(&cache->magazines);
776 palkovsky 583
    spinlock_initialize(&cache->slablock, "slab_lock");
584
    spinlock_initialize(&cache->maglock, "slab_maglock");
789 palkovsky 585
    if (! (cache->flags & SLAB_CACHE_NOMAGAZINE))
586
        make_magcache(cache);
759 palkovsky 587
 
588
    /* Compute slab sizes, object counts in slabs etc. */
589
    if (cache->size < SLAB_INSIDE_SIZE)
590
        cache->flags |= SLAB_CACHE_SLINSIDE;
591
 
762 palkovsky 592
    /* Minimum slab order */
771 palkovsky 593
    pages = ((cache->size-1) >> PAGE_WIDTH) + 1;
594
    cache->order = fnzb(pages);
766 palkovsky 595
 
762 palkovsky 596
    while (badness(cache) > SLAB_MAX_BADNESS(cache)) {
597
        cache->order += 1;
598
    }
599
    cache->objects = comp_objects(cache);
766 palkovsky 600
    /* If info fits in, put it inside */
601
    if (badness(cache) > sizeof(slab_t))
602
        cache->flags |= SLAB_CACHE_SLINSIDE;
762 palkovsky 603
 
783 palkovsky 604
    /* Add cache to cache list */
605
    ipl = interrupts_disable();
759 palkovsky 606
    spinlock_lock(&slab_cache_lock);
607
 
608
    list_append(&cache->link, &slab_cache_list);
609
 
610
    spinlock_unlock(&slab_cache_lock);
783 palkovsky 611
    interrupts_restore(ipl);
759 palkovsky 612
}
613
 
614
/** Create slab cache  */
615
slab_cache_t * slab_cache_create(char *name,
616
                 size_t size,
617
                 size_t align,
618
                 int (*constructor)(void *obj, int kmflag),
787 palkovsky 619
                 int (*destructor)(void *obj),
759 palkovsky 620
                 int flags)
621
{
622
    slab_cache_t *cache;
623
 
769 palkovsky 624
    cache = slab_alloc(&slab_cache_cache, 0);
759 palkovsky 625
    _slab_cache_create(cache, name, size, align, constructor, destructor,
626
               flags);
627
    return cache;
628
}
629
 
630
/**
631
 * Reclaim space occupied by objects that are already free
632
 *
633
 * @param flags If contains SLAB_RECLAIM_ALL, do aggressive freeing
634
 * @return Number of freed pages
635
 */
636
static count_t _slab_reclaim(slab_cache_t *cache, int flags)
637
{
638
    int i;
639
    slab_magazine_t *mag;
640
    count_t frames = 0;
781 palkovsky 641
    int magcount;
759 palkovsky 642
 
643
    if (cache->flags & SLAB_CACHE_NOMAGAZINE)
644
        return 0; /* Nothing to do */
781 palkovsky 645
 
646
    /* We count up to original magazine count to avoid
647
     * endless loop
648
     */
649
    magcount = atomic_get(&cache->magazine_counter);
650
    while (magcount-- && (mag=get_mag_from_cache(cache,0))) {
651
        frames += magazine_destroy(cache,mag);
652
        if (!(flags & SLAB_RECLAIM_ALL) && frames)
653
            break;
769 palkovsky 654
    }
759 palkovsky 655
 
656
    if (flags & SLAB_RECLAIM_ALL) {
781 palkovsky 657
        /* Free cpu-bound magazines */
759 palkovsky 658
        /* Destroy CPU magazines */
659
        for (i=0; i<config.cpu_count; i++) {
781 palkovsky 660
            spinlock_lock(&cache->mag_cache[i].lock);
661
 
759 palkovsky 662
            mag = cache->mag_cache[i].current;
663
            if (mag)
664
                frames += magazine_destroy(cache, mag);
665
            cache->mag_cache[i].current = NULL;
666
 
667
            mag = cache->mag_cache[i].last;
668
            if (mag)
669
                frames += magazine_destroy(cache, mag);
670
            cache->mag_cache[i].last = NULL;
781 palkovsky 671
 
672
            spinlock_unlock(&cache->mag_cache[i].lock);
759 palkovsky 673
        }
674
    }
767 palkovsky 675
 
759 palkovsky 676
    return frames;
677
}
678
 
679
/** Check that there are no slabs and remove cache from system  */
680
void slab_cache_destroy(slab_cache_t *cache)
681
{
781 palkovsky 682
    ipl_t ipl;
683
 
684
    /* First remove cache from link, so that we don't need
685
     * to disable interrupts later
686
     */
687
 
688
    ipl = interrupts_disable();
689
    spinlock_lock(&slab_cache_lock);
690
 
691
    list_remove(&cache->link);
692
 
693
    spinlock_unlock(&slab_cache_lock);
694
    interrupts_restore(ipl);
695
 
759 palkovsky 696
    /* Do not lock anything, we assume the software is correct and
697
     * does not touch the cache when it decides to destroy it */
698
 
699
    /* Destroy all magazines */
700
    _slab_reclaim(cache, SLAB_RECLAIM_ALL);
701
 
702
    /* All slabs must be empty */
703
    if (!list_empty(&cache->full_slabs) \
704
        || !list_empty(&cache->partial_slabs))
705
        panic("Destroying cache that is not empty.");
706
 
789 palkovsky 707
    if (!(cache->flags & SLAB_CACHE_NOMAGAZINE))
791 palkovsky 708
        kfree(cache->mag_cache);
769 palkovsky 709
    slab_free(&slab_cache_cache, cache);
759 palkovsky 710
}
711
 
712
/** Allocate new object from cache - if no flags given, always returns
713
    memory */
714
void * slab_alloc(slab_cache_t *cache, int flags)
715
{
716
    ipl_t ipl;
717
    void *result = NULL;
773 palkovsky 718
 
759 palkovsky 719
    /* Disable interrupts to avoid deadlocks with interrupt handlers */
720
    ipl = interrupts_disable();
771 palkovsky 721
 
814 palkovsky 722
    if (!(cache->flags & SLAB_CACHE_NOMAGAZINE)) {
759 palkovsky 723
        result = magazine_obj_get(cache);
814 palkovsky 724
    }
776 palkovsky 725
    if (!result)
759 palkovsky 726
        result = slab_obj_create(cache, flags);
727
 
769 palkovsky 728
    interrupts_restore(ipl);
729
 
764 palkovsky 730
    if (result)
731
        atomic_inc(&cache->allocated_objs);
732
 
759 palkovsky 733
    return result;
734
}
735
 
771 palkovsky 736
/** Return object to cache, use slab if known  */
737
static void _slab_free(slab_cache_t *cache, void *obj, slab_t *slab)
759 palkovsky 738
{
739
    ipl_t ipl;
740
 
741
    ipl = interrupts_disable();
742
 
762 palkovsky 743
    if ((cache->flags & SLAB_CACHE_NOMAGAZINE) \
744
        || magazine_obj_put(cache, obj)) {
776 palkovsky 745
 
771 palkovsky 746
        slab_obj_destroy(cache, obj, slab);
776 palkovsky 747
 
759 palkovsky 748
    }
769 palkovsky 749
    interrupts_restore(ipl);
764 palkovsky 750
    atomic_dec(&cache->allocated_objs);
759 palkovsky 751
}
752
 
771 palkovsky 753
/** Return slab object to cache */
754
void slab_free(slab_cache_t *cache, void *obj)
755
{
756
    _slab_free(cache,obj,NULL);
757
}
758
 
759 palkovsky 759
/* Go through all caches and reclaim what is possible */
760
count_t slab_reclaim(int flags)
761
{
762
    slab_cache_t *cache;
763
    link_t *cur;
764
    count_t frames = 0;
765
 
766
    spinlock_lock(&slab_cache_lock);
767
 
776 palkovsky 768
    /* TODO: Add assert, that interrupts are disabled, otherwise
769
     * memory allocation from interrupts can deadlock.
770
     */
771
 
759 palkovsky 772
    for (cur = slab_cache_list.next;cur!=&slab_cache_list; cur=cur->next) {
773
        cache = list_get_instance(cur, slab_cache_t, link);
774
        frames += _slab_reclaim(cache, flags);
775
    }
776
 
777
    spinlock_unlock(&slab_cache_lock);
778
 
779
    return frames;
780
}
781
 
782
 
783
/* Print list of slabs */
784
void slab_print_list(void)
785
{
786
    slab_cache_t *cache;
787
    link_t *cur;
783 palkovsky 788
    ipl_t ipl;
789
 
790
    ipl = interrupts_disable();
759 palkovsky 791
    spinlock_lock(&slab_cache_lock);
767 palkovsky 792
    printf("SLAB name\tOsize\tPages\tObj/pg\tSlabs\tCached\tAllocobjs\tCtl\n");
759 palkovsky 793
    for (cur = slab_cache_list.next;cur!=&slab_cache_list; cur=cur->next) {
794
        cache = list_get_instance(cur, slab_cache_t, link);
767 palkovsky 795
        printf("%s\t%d\t%d\t%d\t%d\t%d\t%d\t\t%s\n", cache->name, cache->size,
766 palkovsky 796
               (1 << cache->order), cache->objects,
767 palkovsky 797
               atomic_get(&cache->allocated_slabs),
798
               atomic_get(&cache->cached_objs),
766 palkovsky 799
               atomic_get(&cache->allocated_objs),
800
               cache->flags & SLAB_CACHE_SLINSIDE ? "In" : "Out");
759 palkovsky 801
    }
802
    spinlock_unlock(&slab_cache_lock);
783 palkovsky 803
    interrupts_restore(ipl);
759 palkovsky 804
}
805
 
806
void slab_cache_init(void)
807
{
771 palkovsky 808
    int i, size;
809
 
759 palkovsky 810
    /* Initialize magazine cache */
811
    _slab_cache_create(&mag_cache,
812
               "slab_magazine",
813
               sizeof(slab_magazine_t)+SLAB_MAG_SIZE*sizeof(void*),
814
               sizeof(__address),
815
               NULL, NULL,
769 palkovsky 816
               SLAB_CACHE_NOMAGAZINE | SLAB_CACHE_SLINSIDE);
817
    /* Initialize slab_cache cache */
818
    _slab_cache_create(&slab_cache_cache,
819
               "slab_cache",
789 palkovsky 820
               sizeof(slab_cache_cache),
769 palkovsky 821
               sizeof(__address),
822
               NULL, NULL,
823
               SLAB_CACHE_NOMAGAZINE | SLAB_CACHE_SLINSIDE);
824
    /* Initialize external slab cache */
825
    slab_extern_cache = slab_cache_create("slab_extern",
826
                          sizeof(slab_t),
827
                          0, NULL, NULL,
789 palkovsky 828
                          SLAB_CACHE_SLINSIDE | SLAB_CACHE_MAGDEFERRED);
759 palkovsky 829
 
830
    /* Initialize structures for malloc */
771 palkovsky 831
    for (i=0, size=(1<<SLAB_MIN_MALLOC_W);
832
         i < (SLAB_MAX_MALLOC_W-SLAB_MIN_MALLOC_W+1);
833
         i++, size <<= 1) {
834
        malloc_caches[i] = slab_cache_create(malloc_names[i],
835
                             size, 0,
789 palkovsky 836
                             NULL,NULL, SLAB_CACHE_MAGDEFERRED);
771 palkovsky 837
    }
778 palkovsky 838
#ifdef CONFIG_DEBUG       
839
    _slab_initialized = 1;
840
#endif
759 palkovsky 841
}
771 palkovsky 842
 
789 palkovsky 843
/** Enable cpu_cache
844
 *
845
 * Kernel calls this function, when it knows the real number of
846
 * processors.
847
 * Allocate slab for cpucache and enable it on all existing
848
 * slabs that are SLAB_CACHE_MAGDEFERRED
849
 */
850
void slab_enable_cpucache(void)
851
{
852
    link_t *cur;
853
    slab_cache_t *s;
854
 
791 palkovsky 855
#ifdef CONFIG_DEBUG
856
    _slab_initialized = 2;
857
#endif
858
 
789 palkovsky 859
    spinlock_lock(&slab_cache_lock);
860
 
861
    for (cur=slab_cache_list.next; cur != &slab_cache_list;cur=cur->next){
862
        s = list_get_instance(cur, slab_cache_t, link);
863
        if ((s->flags & SLAB_CACHE_MAGDEFERRED) != SLAB_CACHE_MAGDEFERRED)
864
            continue;
865
        make_magcache(s);
866
        s->flags &= ~SLAB_CACHE_MAGDEFERRED;
867
    }
868
 
869
    spinlock_unlock(&slab_cache_lock);
870
}
871
 
771 palkovsky 872
/**************************************/
873
/* kalloc/kfree functions             */
874
void * kalloc(unsigned int size, int flags)
875
{
876
    int idx;
778 palkovsky 877
 
878
    ASSERT(_slab_initialized);
771 palkovsky 879
    ASSERT( size && size <= (1 << SLAB_MAX_MALLOC_W));
880
 
881
    if (size < (1 << SLAB_MIN_MALLOC_W))
882
        size = (1 << SLAB_MIN_MALLOC_W);
883
 
884
    idx = fnzb(size-1) - SLAB_MIN_MALLOC_W + 1;
885
 
886
    return slab_alloc(malloc_caches[idx], flags);
887
}
888
 
889
 
890
void kfree(void *obj)
891
{
781 palkovsky 892
    slab_t *slab;
893
 
894
    if (!obj) return;
895
 
896
    slab = obj2slab(obj);
771 palkovsky 897
    _slab_free(slab->cache, obj, slab);
898
}