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759 palkovsky 1
/*
2071 jermar 2
 * Copyright (c) 2006 Ondrej Palkovsky
759 palkovsky 3
 * All rights reserved.
4
 *
5
 * Redistribution and use in source and binary forms, with or without
6
 * modification, are permitted provided that the following conditions
7
 * are met:
8
 *
9
 * - Redistributions of source code must retain the above copyright
10
 *   notice, this list of conditions and the following disclaimer.
11
 * - Redistributions in binary form must reproduce the above copyright
12
 *   notice, this list of conditions and the following disclaimer in the
13
 *   documentation and/or other materials provided with the distribution.
14
 * - The name of the author may not be used to endorse or promote products
15
 *   derived from this software without specific prior written permission.
16
 *
17
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
 */
28
 
1757 jermar 29
/** @addtogroup genericmm
1702 cejka 30
 * @{
31
 */
32
 
1248 jermar 33
/**
1702 cejka 34
 * @file
1248 jermar 35
 * @brief   Slab allocator.
769 palkovsky 36
 *
1248 jermar 37
 * The slab allocator is closely modelled after OpenSolaris slab allocator.
38
 * @see http://www.usenix.org/events/usenix01/full_papers/bonwick/bonwick_html/
39
 *
769 palkovsky 40
 * with the following exceptions:
1248 jermar 41
 * @li empty slabs are deallocated immediately
769 palkovsky 42
 *     (in Linux they are kept in linked list, in Solaris ???)
1248 jermar 43
 * @li empty magazines are deallocated when not needed
769 palkovsky 44
 *     (in Solaris they are held in linked list in slab cache)
45
 *
1248 jermar 46
 * Following features are not currently supported but would be easy to do:
47
 * @li cache coloring
48
 * @li dynamic magazine growing (different magazine sizes are already
1144 jermar 49
 *     supported, but we would need to adjust allocation strategy)
769 palkovsky 50
 *
1248 jermar 51
 * The slab allocator supports per-CPU caches ('magazines') to facilitate
769 palkovsky 52
 * good SMP scaling.
53
 *
54
 * When a new object is being allocated, it is first checked, if it is
1554 jermar 55
 * available in a CPU-bound magazine. If it is not found there, it is
56
 * allocated from a CPU-shared slab - if a partially full one is found,
57
 * it is used, otherwise a new one is allocated.
769 palkovsky 58
 *
1554 jermar 59
 * When an object is being deallocated, it is put to a CPU-bound magazine.
60
 * If there is no such magazine, a new one is allocated (if this fails,
1248 jermar 61
 * the object is deallocated into slab). If the magazine is full, it is
1554 jermar 62
 * put into cpu-shared list of magazines and a new one is allocated.
769 palkovsky 63
 *
1554 jermar 64
 * The CPU-bound magazine is actually a pair of magazines in order to avoid
769 palkovsky 65
 * thrashing when somebody is allocating/deallocating 1 item at the magazine
66
 * size boundary. LIFO order is enforced, which should avoid fragmentation
67
 * as much as possible.
68
 *  
1554 jermar 69
 * Every cache contains list of full slabs and list of partially full slabs.
1248 jermar 70
 * Empty slabs are immediately freed (thrashing will be avoided because
769 palkovsky 71
 * of magazines).
72
 *
1248 jermar 73
 * The slab information structure is kept inside the data area, if possible.
769 palkovsky 74
 * The cache can be marked that it should not use magazines. This is used
1248 jermar 75
 * only for slab related caches to avoid deadlocks and infinite recursion
76
 * (the slab allocator uses itself for allocating all it's control structures).
769 palkovsky 77
 *
1554 jermar 78
 * The slab allocator allocates a lot of space and does not free it. When
79
 * the frame allocator fails to allocate a frame, it calls slab_reclaim().
769 palkovsky 80
 * It tries 'light reclaim' first, then brutal reclaim. The light reclaim
81
 * releases slabs from cpu-shared magazine-list, until at least 1 slab
82
 * is deallocated in each cache (this algorithm should probably change).
83
 * The brutal reclaim removes all cached objects, even from CPU-bound
84
 * magazines.
85
 *
1757 jermar 86
 * @todo
1248 jermar 87
 * For better CPU-scaling the magazine allocation strategy should
775 palkovsky 88
 * be extended. Currently, if the cache does not have magazine, it asks
89
 * for non-cpu cached magazine cache to provide one. It might be feasible
90
 * to add cpu-cached magazine cache (which would allocate it's magazines
91
 * from non-cpu-cached mag. cache). This would provide a nice per-cpu
92
 * buffer. The other possibility is to use the per-cache
93
 * 'empty-magazine-list', which decreases competing for 1 per-system
94
 * magazine cache.
95
 *
1757 jermar 96
 * @todo
97
 * it might be good to add granularity of locks even to slab level,
98
 * we could then try_spinlock over all partial slabs and thus improve
99
 * scalability even on slab level
769 palkovsky 100
 */
101
 
759 palkovsky 102
#include <synch/spinlock.h>
103
#include <mm/slab.h>
788 jermar 104
#include <adt/list.h>
759 palkovsky 105
#include <memstr.h>
106
#include <align.h>
762 palkovsky 107
#include <mm/frame.h>
759 palkovsky 108
#include <config.h>
109
#include <print.h>
110
#include <arch.h>
111
#include <panic.h>
762 palkovsky 112
#include <debug.h>
771 palkovsky 113
#include <bitops.h>
2124 decky 114
#include <macros.h>
759 palkovsky 115
 
116
SPINLOCK_INITIALIZE(slab_cache_lock);
769 palkovsky 117
static LIST_INITIALIZE(slab_cache_list);
759 palkovsky 118
 
769 palkovsky 119
/** Magazine cache */
120
static slab_cache_t mag_cache;
121
/** Cache for cache descriptors */
122
static slab_cache_t slab_cache_cache;
123
/** Cache for external slab descriptors
124
 * This time we want per-cpu cache, so do not make it static
1248 jermar 125
 * - using slab for internal slab structures will not deadlock,
769 palkovsky 126
 *   as all slab structures are 'small' - control structures of
127
 *   their caches do not require further allocation
128
 */
129
static slab_cache_t *slab_extern_cache;
771 palkovsky 130
/** Caches for malloc */
2124 decky 131
static slab_cache_t *malloc_caches[SLAB_MAX_MALLOC_W - SLAB_MIN_MALLOC_W + 1];
4174 decky 132
static char *malloc_names[] =  {
2124 decky 133
    "malloc-16",
134
    "malloc-32",
135
    "malloc-64",
136
    "malloc-128",
137
    "malloc-256",
138
    "malloc-512",
139
    "malloc-1K",
140
    "malloc-2K",
141
    "malloc-4K",
142
    "malloc-8K",
143
    "malloc-16K",
144
    "malloc-32K",
145
    "malloc-64K",
146
    "malloc-128K",
4174 decky 147
    "malloc-256K",
148
    "malloc-512K",
149
    "malloc-1M",
150
    "malloc-2M",
151
    "malloc-4M"
771 palkovsky 152
};
762 palkovsky 153
 
769 palkovsky 154
/** Slab descriptor */
762 palkovsky 155
typedef struct {
1950 jermar 156
    slab_cache_t *cache;    /**< Pointer to parent cache. */
157
    link_t link;        /**< List of full/partial slabs. */
158
    void *start;        /**< Start address of first available item. */
4490 decky 159
    size_t available;   /**< Count of available items in this slab. */
160
    size_t nextavail;   /**< The index of next available item. */
2124 decky 161
} slab_t;
762 palkovsky 162
 
791 palkovsky 163
#ifdef CONFIG_DEBUG
164
static int _slab_initialized = 0;
165
#endif
166
 
759 palkovsky 167
/**************************************/
1248 jermar 168
/* Slab allocation functions          */
759 palkovsky 169
 
762 palkovsky 170
/**
171
 * Allocate frames for slab space and initialize
172
 *
173
 */
3180 jermar 174
static slab_t *slab_space_alloc(slab_cache_t *cache, int flags)
762 palkovsky 175
{
176
    void *data;
177
    slab_t *slab;
178
    size_t fsize;
2745 decky 179
    unsigned int i;
4490 decky 180
    size_t zone = 0;
814 palkovsky 181
 
1766 palkovsky 182
    data = frame_alloc_generic(cache->order, FRAME_KA | flags, &zone);
183
    if (!data) {
762 palkovsky 184
        return NULL;
764 palkovsky 185
    }
3180 jermar 186
    if (!(cache->flags & SLAB_CACHE_SLINSIDE)) {
769 palkovsky 187
        slab = slab_alloc(slab_extern_cache, flags);
762 palkovsky 188
        if (!slab) {
1760 palkovsky 189
            frame_free(KA2PA(data));
762 palkovsky 190
            return NULL;
191
        }
192
    } else {
193
        fsize = (PAGE_SIZE << cache->order);
194
        slab = data + fsize - sizeof(*slab);
195
    }
1288 jermar 196
 
762 palkovsky 197
    /* Fill in slab structures */
2745 decky 198
    for (i = 0; i < ((unsigned int) 1 << cache->order); i++)
199
        frame_set_parent(ADDR2PFN(KA2PA(data)) + i, slab, zone);
762 palkovsky 200
 
201
    slab->start = data;
202
    slab->available = cache->objects;
203
    slab->nextavail = 0;
767 palkovsky 204
    slab->cache = cache;
762 palkovsky 205
 
2745 decky 206
    for (i = 0; i < cache->objects; i++)
3180 jermar 207
        *((int *) (slab->start + i*cache->size)) = i + 1;
764 palkovsky 208
 
209
    atomic_inc(&cache->allocated_slabs);
762 palkovsky 210
    return slab;
211
}
212
 
759 palkovsky 213
/**
1248 jermar 214
 * Deallocate space associated with slab
762 palkovsky 215
 *
216
 * @return number of freed frames
217
 */
4490 decky 218
static size_t slab_space_free(slab_cache_t *cache, slab_t *slab)
762 palkovsky 219
{
1760 palkovsky 220
    frame_free(KA2PA(slab->start));
768 palkovsky 221
    if (! (cache->flags & SLAB_CACHE_SLINSIDE))
769 palkovsky 222
        slab_free(slab_extern_cache, slab);
764 palkovsky 223
 
224
    atomic_dec(&cache->allocated_slabs);
225
 
762 palkovsky 226
    return 1 << cache->order;
227
}
228
 
229
/** Map object to slab structure */
230
static slab_t * obj2slab(void *obj)
231
{
2124 decky 232
    return (slab_t *) frame_get_parent(ADDR2PFN(KA2PA(obj)), 0);
762 palkovsky 233
}
234
 
235
/**************************************/
1248 jermar 236
/* Slab functions */
762 palkovsky 237
 
238
 
239
/**
759 palkovsky 240
 * Return object to slab and call a destructor
241
 *
762 palkovsky 242
 * @param slab If the caller knows directly slab of the object, otherwise NULL
243
 *
759 palkovsky 244
 * @return Number of freed pages
245
 */
4490 decky 246
static size_t slab_obj_destroy(slab_cache_t *cache, void *obj, slab_t *slab)
759 palkovsky 247
{
787 palkovsky 248
    int freed = 0;
249
 
762 palkovsky 250
    if (!slab)
251
        slab = obj2slab(obj);
252
 
767 palkovsky 253
    ASSERT(slab->cache == cache);
254
 
787 palkovsky 255
    if (cache->destructor)
256
        freed = cache->destructor(obj);
257
 
776 palkovsky 258
    spinlock_lock(&cache->slablock);
789 palkovsky 259
    ASSERT(slab->available < cache->objects);
776 palkovsky 260
 
762 palkovsky 261
    *((int *)obj) = slab->nextavail;
3180 jermar 262
    slab->nextavail = (obj - slab->start) / cache->size;
762 palkovsky 263
    slab->available++;
264
 
265
    /* Move it to correct list */
266
    if (slab->available == cache->objects) {
267
        /* Free associated memory */
268
        list_remove(&slab->link);
782 palkovsky 269
        spinlock_unlock(&cache->slablock);
270
 
787 palkovsky 271
        return freed + slab_space_free(cache, slab);
782 palkovsky 272
 
780 palkovsky 273
    } else if (slab->available == 1) {
274
        /* It was in full, move to partial */
275
        list_remove(&slab->link);
276
        list_prepend(&slab->link, &cache->partial_slabs);
762 palkovsky 277
    }
783 palkovsky 278
    spinlock_unlock(&cache->slablock);
787 palkovsky 279
    return freed;
759 palkovsky 280
}
281
 
282
/**
283
 * Take new object from slab or create new if needed
284
 *
285
 * @return Object address or null
286
 */
3180 jermar 287
static void *slab_obj_create(slab_cache_t *cache, int flags)
759 palkovsky 288
{
762 palkovsky 289
    slab_t *slab;
290
    void *obj;
291
 
776 palkovsky 292
    spinlock_lock(&cache->slablock);
293
 
762 palkovsky 294
    if (list_empty(&cache->partial_slabs)) {
295
        /* Allow recursion and reclaiming
1248 jermar 296
         * - this should work, as the slab control structures
1288 jermar 297
         *   are small and do not need to allocate with anything
298
         *   other than frame_alloc when they are allocating,
762 palkovsky 299
         *   that's why we should get recursion at most 1-level deep
300
         */
776 palkovsky 301
        spinlock_unlock(&cache->slablock);
762 palkovsky 302
        slab = slab_space_alloc(cache, flags);
780 palkovsky 303
        if (!slab)
304
            return NULL;
776 palkovsky 305
        spinlock_lock(&cache->slablock);
762 palkovsky 306
    } else {
3180 jermar 307
        slab = list_get_instance(cache->partial_slabs.next, slab_t,
308
            link);
762 palkovsky 309
        list_remove(&slab->link);
310
    }
311
    obj = slab->start + slab->nextavail * cache->size;
312
    slab->nextavail = *((int *)obj);
313
    slab->available--;
787 palkovsky 314
 
1950 jermar 315
    if (!slab->available)
764 palkovsky 316
        list_prepend(&slab->link, &cache->full_slabs);
762 palkovsky 317
    else
764 palkovsky 318
        list_prepend(&slab->link, &cache->partial_slabs);
776 palkovsky 319
 
320
    spinlock_unlock(&cache->slablock);
787 palkovsky 321
 
322
    if (cache->constructor && cache->constructor(obj, flags)) {
323
        /* Bad, bad, construction failed */
324
        slab_obj_destroy(cache, obj, slab);
325
        return NULL;
326
    }
762 palkovsky 327
    return obj;
759 palkovsky 328
}
329
 
330
/**************************************/
331
/* CPU-Cache slab functions */
332
 
333
/**
781 palkovsky 334
 * Finds a full magazine in cache, takes it from list
335
 * and returns it
336
 *
337
 * @param first If true, return first, else last mag
338
 */
3180 jermar 339
static slab_magazine_t *get_mag_from_cache(slab_cache_t *cache, int first)
781 palkovsky 340
{
341
    slab_magazine_t *mag = NULL;
342
    link_t *cur;
343
 
344
    spinlock_lock(&cache->maglock);
345
    if (!list_empty(&cache->magazines)) {
346
        if (first)
347
            cur = cache->magazines.next;
348
        else
349
            cur = cache->magazines.prev;
350
        mag = list_get_instance(cur, slab_magazine_t, link);
351
        list_remove(&mag->link);
352
        atomic_dec(&cache->magazine_counter);
353
    }
354
    spinlock_unlock(&cache->maglock);
355
    return mag;
356
}
357
 
358
/** Prepend magazine to magazine list in cache */
359
static void put_mag_to_cache(slab_cache_t *cache, slab_magazine_t *mag)
360
{
361
    spinlock_lock(&cache->maglock);
362
 
363
    list_prepend(&mag->link, &cache->magazines);
364
    atomic_inc(&cache->magazine_counter);
365
 
366
    spinlock_unlock(&cache->maglock);
367
}
368
 
369
/**
759 palkovsky 370
 * Free all objects in magazine and free memory associated with magazine
371
 *
372
 * @return Number of freed pages
373
 */
4490 decky 374
static size_t magazine_destroy(slab_cache_t *cache, slab_magazine_t *mag)
759 palkovsky 375
{
2745 decky 376
    unsigned int i;
4490 decky 377
    size_t frames = 0;
759 palkovsky 378
 
2745 decky 379
    for (i = 0; i < mag->busy; i++) {
762 palkovsky 380
        frames += slab_obj_destroy(cache, mag->objs[i], NULL);
767 palkovsky 381
        atomic_dec(&cache->cached_objs);
382
    }
759 palkovsky 383
 
384
    slab_free(&mag_cache, mag);
385
 
386
    return frames;
387
}
388
 
389
/**
769 palkovsky 390
 * Find full magazine, set it as current and return it
391
 *
392
 * Assume cpu_magazine lock is held
393
 */
3180 jermar 394
static slab_magazine_t *get_full_current_mag(slab_cache_t *cache)
769 palkovsky 395
{
396
    slab_magazine_t *cmag, *lastmag, *newmag;
397
 
398
    cmag = cache->mag_cache[CPU->id].current;
399
    lastmag = cache->mag_cache[CPU->id].last;
400
    if (cmag) { /* First try local CPU magazines */
401
        if (cmag->busy)
402
            return cmag;
403
 
404
        if (lastmag && lastmag->busy) {
405
            cache->mag_cache[CPU->id].current = lastmag;
406
            cache->mag_cache[CPU->id].last = cmag;
407
            return lastmag;
408
        }
409
    }
410
    /* Local magazines are empty, import one from magazine list */
781 palkovsky 411
    newmag = get_mag_from_cache(cache, 1);
412
    if (!newmag)
769 palkovsky 413
        return NULL;
414
 
415
    if (lastmag)
781 palkovsky 416
        magazine_destroy(cache, lastmag);
417
 
769 palkovsky 418
    cache->mag_cache[CPU->id].last = cmag;
419
    cache->mag_cache[CPU->id].current = newmag;
420
    return newmag;
421
}
422
 
423
/**
759 palkovsky 424
 * Try to find object in CPU-cache magazines
425
 *
426
 * @return Pointer to object or NULL if not available
427
 */
3180 jermar 428
static void *magazine_obj_get(slab_cache_t *cache)
759 palkovsky 429
{
430
    slab_magazine_t *mag;
767 palkovsky 431
    void *obj;
759 palkovsky 432
 
772 palkovsky 433
    if (!CPU)
434
        return NULL;
435
 
759 palkovsky 436
    spinlock_lock(&cache->mag_cache[CPU->id].lock);
437
 
769 palkovsky 438
    mag = get_full_current_mag(cache);
439
    if (!mag) {
440
        spinlock_unlock(&cache->mag_cache[CPU->id].lock);
441
        return NULL;
759 palkovsky 442
    }
767 palkovsky 443
    obj = mag->objs[--mag->busy];
759 palkovsky 444
    spinlock_unlock(&cache->mag_cache[CPU->id].lock);
767 palkovsky 445
    atomic_dec(&cache->cached_objs);
446
 
447
    return obj;
759 palkovsky 448
}
449
 
450
/**
768 palkovsky 451
 * Assure that the current magazine is empty, return pointer to it, or NULL if
769 palkovsky 452
 * no empty magazine is available and cannot be allocated
759 palkovsky 453
 *
773 palkovsky 454
 * Assume mag_cache[CPU->id].lock is held
455
 *
759 palkovsky 456
 * We have 2 magazines bound to processor.
457
 * First try the current.
458
 *  If full, try the last.
459
 *   If full, put to magazines list.
460
 *   allocate new, exchange last & current
461
 *
768 palkovsky 462
 */
3180 jermar 463
static slab_magazine_t *make_empty_current_mag(slab_cache_t *cache)
768 palkovsky 464
{
465
    slab_magazine_t *cmag,*lastmag,*newmag;
466
 
467
    cmag = cache->mag_cache[CPU->id].current;
468
    lastmag = cache->mag_cache[CPU->id].last;
469
 
470
    if (cmag) {
471
        if (cmag->busy < cmag->size)
472
            return cmag;
473
        if (lastmag && lastmag->busy < lastmag->size) {
474
            cache->mag_cache[CPU->id].last = cmag;
475
            cache->mag_cache[CPU->id].current = lastmag;
476
            return lastmag;
477
        }
478
    }
479
    /* current | last are full | nonexistent, allocate new */
480
    /* We do not want to sleep just because of caching */
481
    /* Especially we do not want reclaiming to start, as
482
     * this would deadlock */
483
    newmag = slab_alloc(&mag_cache, FRAME_ATOMIC | FRAME_NO_RECLAIM);
484
    if (!newmag)
485
        return NULL;
486
    newmag->size = SLAB_MAG_SIZE;
487
    newmag->busy = 0;
488
 
489
    /* Flush last to magazine list */
781 palkovsky 490
    if (lastmag)
491
        put_mag_to_cache(cache, lastmag);
492
 
768 palkovsky 493
    /* Move current as last, save new as current */
494
    cache->mag_cache[CPU->id].last = cmag; 
495
    cache->mag_cache[CPU->id].current = newmag;
496
 
497
    return newmag;
498
}
499
 
500
/**
501
 * Put object into CPU-cache magazine
502
 *
759 palkovsky 503
 * @return 0 - success, -1 - could not get memory
504
 */
505
static int magazine_obj_put(slab_cache_t *cache, void *obj)
506
{
507
    slab_magazine_t *mag;
508
 
772 palkovsky 509
    if (!CPU)
510
        return -1;
511
 
759 palkovsky 512
    spinlock_lock(&cache->mag_cache[CPU->id].lock);
768 palkovsky 513
 
514
    mag = make_empty_current_mag(cache);
769 palkovsky 515
    if (!mag) {
516
        spinlock_unlock(&cache->mag_cache[CPU->id].lock);
517
        return -1;
518
    }
759 palkovsky 519
 
520
    mag->objs[mag->busy++] = obj;
521
 
522
    spinlock_unlock(&cache->mag_cache[CPU->id].lock);
767 palkovsky 523
    atomic_inc(&cache->cached_objs);
759 palkovsky 524
    return 0;
525
}
526
 
527
 
528
/**************************************/
1248 jermar 529
/* Slab cache functions */
759 palkovsky 530
 
762 palkovsky 531
/** Return number of objects that fit in certain cache size */
2745 decky 532
static unsigned int comp_objects(slab_cache_t *cache)
762 palkovsky 533
{
534
    if (cache->flags & SLAB_CACHE_SLINSIDE)
3180 jermar 535
        return ((PAGE_SIZE << cache->order) - sizeof(slab_t)) /
536
            cache->size;
762 palkovsky 537
    else
538
        return (PAGE_SIZE << cache->order) / cache->size;
539
}
540
 
541
/** Return wasted space in slab */
2745 decky 542
static unsigned int badness(slab_cache_t *cache)
762 palkovsky 543
{
2745 decky 544
    unsigned int objects;
545
    unsigned int ssize;
762 palkovsky 546
 
547
    objects = comp_objects(cache);
548
    ssize = PAGE_SIZE << cache->order;
549
    if (cache->flags & SLAB_CACHE_SLINSIDE)
550
        ssize -= sizeof(slab_t);
2745 decky 551
    return ssize - objects * cache->size;
762 palkovsky 552
}
553
 
789 palkovsky 554
/**
555
 * Initialize mag_cache structure in slab cache
556
 */
557
static void make_magcache(slab_cache_t *cache)
558
{
2745 decky 559
    unsigned int i;
791 palkovsky 560
 
561
    ASSERT(_slab_initialized >= 2);
789 palkovsky 562
 
3180 jermar 563
    cache->mag_cache = malloc(sizeof(slab_mag_cache_t) * config.cpu_count,
564
        0);
2745 decky 565
    for (i = 0; i < config.cpu_count; i++) {
3104 svoboda 566
        memsetb(&cache->mag_cache[i], sizeof(cache->mag_cache[i]), 0);
3180 jermar 567
        spinlock_initialize(&cache->mag_cache[i].lock,
568
            "slab_maglock_cpu");
789 palkovsky 569
    }
570
}
571
 
759 palkovsky 572
/** Initialize allocated memory as a slab cache */
573
static void
3180 jermar 574
_slab_cache_create(slab_cache_t *cache, char *name, size_t size, size_t align,
575
    int (*constructor)(void *obj, int kmflag), int (*destructor)(void *obj),
576
    int flags)
759 palkovsky 577
{
771 palkovsky 578
    int pages;
783 palkovsky 579
    ipl_t ipl;
759 palkovsky 580
 
3104 svoboda 581
    memsetb(cache, sizeof(*cache), 0);
759 palkovsky 582
    cache->name = name;
583
 
1780 jermar 584
    if (align < sizeof(unative_t))
585
        align = sizeof(unative_t);
766 palkovsky 586
    size = ALIGN_UP(size, align);
587
 
762 palkovsky 588
    cache->size = size;
759 palkovsky 589
 
590
    cache->constructor = constructor;
591
    cache->destructor = destructor;
592
    cache->flags = flags;
593
 
594
    list_initialize(&cache->full_slabs);
595
    list_initialize(&cache->partial_slabs);
596
    list_initialize(&cache->magazines);
776 palkovsky 597
    spinlock_initialize(&cache->slablock, "slab_lock");
598
    spinlock_initialize(&cache->maglock, "slab_maglock");
3180 jermar 599
    if (!(cache->flags & SLAB_CACHE_NOMAGAZINE))
789 palkovsky 600
        make_magcache(cache);
759 palkovsky 601
 
602
    /* Compute slab sizes, object counts in slabs etc. */
603
    if (cache->size < SLAB_INSIDE_SIZE)
604
        cache->flags |= SLAB_CACHE_SLINSIDE;
605
 
762 palkovsky 606
    /* Minimum slab order */
1682 palkovsky 607
    pages = SIZE2FRAMES(cache->size);
1677 palkovsky 608
    /* We need the 2^order >= pages */
609
    if (pages == 1)
610
        cache->order = 0;
611
    else
3180 jermar 612
        cache->order = fnzb(pages - 1) + 1;
766 palkovsky 613
 
762 palkovsky 614
    while (badness(cache) > SLAB_MAX_BADNESS(cache)) {
615
        cache->order += 1;
616
    }
617
    cache->objects = comp_objects(cache);
766 palkovsky 618
    /* If info fits in, put it inside */
619
    if (badness(cache) > sizeof(slab_t))
620
        cache->flags |= SLAB_CACHE_SLINSIDE;
762 palkovsky 621
 
783 palkovsky 622
    /* Add cache to cache list */
623
    ipl = interrupts_disable();
759 palkovsky 624
    spinlock_lock(&slab_cache_lock);
625
 
626
    list_append(&cache->link, &slab_cache_list);
627
 
628
    spinlock_unlock(&slab_cache_lock);
783 palkovsky 629
    interrupts_restore(ipl);
759 palkovsky 630
}
631
 
632
/** Create slab cache  */
3180 jermar 633
slab_cache_t *
634
slab_cache_create(char *name, size_t size, size_t align,
635
    int (*constructor)(void *obj, int kmflag), int (*destructor)(void *obj),
636
    int flags)
759 palkovsky 637
{
638
    slab_cache_t *cache;
639
 
769 palkovsky 640
    cache = slab_alloc(&slab_cache_cache, 0);
759 palkovsky 641
    _slab_cache_create(cache, name, size, align, constructor, destructor,
3180 jermar 642
        flags);
759 palkovsky 643
    return cache;
644
}
645
 
646
/**
647
 * Reclaim space occupied by objects that are already free
648
 *
649
 * @param flags If contains SLAB_RECLAIM_ALL, do aggressive freeing
650
 * @return Number of freed pages
651
 */
4490 decky 652
static size_t _slab_reclaim(slab_cache_t *cache, int flags)
759 palkovsky 653
{
2745 decky 654
    unsigned int i;
759 palkovsky 655
    slab_magazine_t *mag;
4490 decky 656
    size_t frames = 0;
781 palkovsky 657
    int magcount;
759 palkovsky 658
 
659
    if (cache->flags & SLAB_CACHE_NOMAGAZINE)
660
        return 0; /* Nothing to do */
781 palkovsky 661
 
662
    /* We count up to original magazine count to avoid
663
     * endless loop
664
     */
665
    magcount = atomic_get(&cache->magazine_counter);
3180 jermar 666
    while (magcount-- && (mag=get_mag_from_cache(cache, 0))) {
781 palkovsky 667
        frames += magazine_destroy(cache,mag);
668
        if (!(flags & SLAB_RECLAIM_ALL) && frames)
669
            break;
769 palkovsky 670
    }
759 palkovsky 671
 
672
    if (flags & SLAB_RECLAIM_ALL) {
781 palkovsky 673
        /* Free cpu-bound magazines */
759 palkovsky 674
        /* Destroy CPU magazines */
2745 decky 675
        for (i = 0; i < config.cpu_count; i++) {
781 palkovsky 676
            spinlock_lock(&cache->mag_cache[i].lock);
677
 
759 palkovsky 678
            mag = cache->mag_cache[i].current;
679
            if (mag)
680
                frames += magazine_destroy(cache, mag);
681
            cache->mag_cache[i].current = NULL;
682
 
683
            mag = cache->mag_cache[i].last;
684
            if (mag)
685
                frames += magazine_destroy(cache, mag);
686
            cache->mag_cache[i].last = NULL;
781 palkovsky 687
 
688
            spinlock_unlock(&cache->mag_cache[i].lock);
759 palkovsky 689
        }
690
    }
767 palkovsky 691
 
759 palkovsky 692
    return frames;
693
}
694
 
695
/** Check that there are no slabs and remove cache from system  */
696
void slab_cache_destroy(slab_cache_t *cache)
697
{
781 palkovsky 698
    ipl_t ipl;
699
 
700
    /* First remove cache from link, so that we don't need
701
     * to disable interrupts later
702
     */
703
 
704
    ipl = interrupts_disable();
705
    spinlock_lock(&slab_cache_lock);
706
 
707
    list_remove(&cache->link);
708
 
709
    spinlock_unlock(&slab_cache_lock);
710
    interrupts_restore(ipl);
711
 
759 palkovsky 712
    /* Do not lock anything, we assume the software is correct and
713
     * does not touch the cache when it decides to destroy it */
714
 
715
    /* Destroy all magazines */
716
    _slab_reclaim(cache, SLAB_RECLAIM_ALL);
717
 
718
    /* All slabs must be empty */
3180 jermar 719
    if (!list_empty(&cache->full_slabs) ||
720
        !list_empty(&cache->partial_slabs))
759 palkovsky 721
        panic("Destroying cache that is not empty.");
722
 
789 palkovsky 723
    if (!(cache->flags & SLAB_CACHE_NOMAGAZINE))
822 palkovsky 724
        free(cache->mag_cache);
769 palkovsky 725
    slab_free(&slab_cache_cache, cache);
759 palkovsky 726
}
727
 
3180 jermar 728
/** Allocate new object from cache - if no flags given, always returns memory */
729
void *slab_alloc(slab_cache_t *cache, int flags)
759 palkovsky 730
{
731
    ipl_t ipl;
732
    void *result = NULL;
773 palkovsky 733
 
759 palkovsky 734
    /* Disable interrupts to avoid deadlocks with interrupt handlers */
735
    ipl = interrupts_disable();
771 palkovsky 736
 
814 palkovsky 737
    if (!(cache->flags & SLAB_CACHE_NOMAGAZINE)) {
759 palkovsky 738
        result = magazine_obj_get(cache);
814 palkovsky 739
    }
776 palkovsky 740
    if (!result)
759 palkovsky 741
        result = slab_obj_create(cache, flags);
742
 
769 palkovsky 743
    interrupts_restore(ipl);
744
 
764 palkovsky 745
    if (result)
746
        atomic_inc(&cache->allocated_objs);
747
 
759 palkovsky 748
    return result;
749
}
750
 
771 palkovsky 751
/** Return object to cache, use slab if known  */
752
static void _slab_free(slab_cache_t *cache, void *obj, slab_t *slab)
759 palkovsky 753
{
754
    ipl_t ipl;
755
 
756
    ipl = interrupts_disable();
757
 
3180 jermar 758
    if ((cache->flags & SLAB_CACHE_NOMAGAZINE) ||
759
        magazine_obj_put(cache, obj)) {
771 palkovsky 760
        slab_obj_destroy(cache, obj, slab);
776 palkovsky 761
 
759 palkovsky 762
    }
769 palkovsky 763
    interrupts_restore(ipl);
764 palkovsky 764
    atomic_dec(&cache->allocated_objs);
759 palkovsky 765
}
766
 
771 palkovsky 767
/** Return slab object to cache */
768
void slab_free(slab_cache_t *cache, void *obj)
769
{
2124 decky 770
    _slab_free(cache, obj, NULL);
771 palkovsky 771
}
772
 
759 palkovsky 773
/* Go through all caches and reclaim what is possible */
4490 decky 774
size_t slab_reclaim(int flags)
759 palkovsky 775
{
776
    slab_cache_t *cache;
777
    link_t *cur;
4490 decky 778
    size_t frames = 0;
759 palkovsky 779
 
780
    spinlock_lock(&slab_cache_lock);
781
 
776 palkovsky 782
    /* TODO: Add assert, that interrupts are disabled, otherwise
783
     * memory allocation from interrupts can deadlock.
784
     */
785
 
3180 jermar 786
    for (cur = slab_cache_list.next; cur != &slab_cache_list;
787
        cur = cur->next) {
759 palkovsky 788
        cache = list_get_instance(cur, slab_cache_t, link);
789
        frames += _slab_reclaim(cache, flags);
790
    }
791
 
792
    spinlock_unlock(&slab_cache_lock);
793
 
794
    return frames;
795
}
796
 
797
 
798
/* Print list of slabs */
799
void slab_print_list(void)
800
{
3183 jermar 801
    int skip = 0;
802
 
3180 jermar 803
    printf("slab name        size     pages  obj/pg slabs  cached allocated"
804
        " ctl\n");
805
    printf("---------------- -------- ------ ------ ------ ------ ---------"
806
        " ---\n");
3183 jermar 807
 
808
    while (true) {
809
        slab_cache_t *cache;
810
        link_t *cur;
811
        ipl_t ipl;
812
        int i;
813
 
814
        /*
815
         * We must not hold the slab_cache_lock spinlock when printing
816
         * the statistics. Otherwise we can easily deadlock if the print
817
         * needs to allocate memory.
818
         *
819
         * Therefore, we walk through the slab cache list, skipping some
820
         * amount of already processed caches during each iteration and
821
         * gathering statistics about the first unprocessed cache. For
822
         * the sake of printing the statistics, we realese the
823
         * slab_cache_lock and reacquire it afterwards. Then the walk
824
         * starts again.
825
         *
826
         * This limits both the efficiency and also accuracy of the
827
         * obtained statistics. The efficiency is decreased because the
828
         * time complexity of the algorithm is quadratic instead of
829
         * linear. The accuracy is impacted because we drop the lock
830
         * after processing one cache. If there is someone else
831
         * manipulating the cache list, we might omit an arbitrary
832
         * number of caches or process one cache multiple times.
833
         * However, we don't bleed for this algorithm for it is only
834
         * statistics.
835
         */
836
 
837
        ipl = interrupts_disable();
838
        spinlock_lock(&slab_cache_lock);
839
 
840
        for (i = 0, cur = slab_cache_list.next;
841
            i < skip && cur != &slab_cache_list;
842
            i++, cur = cur->next)
843
            ;
844
 
845
        if (cur == &slab_cache_list) {
846
            spinlock_unlock(&slab_cache_lock);
847
            interrupts_restore(ipl);
848
            break;
849
        }
850
 
851
        skip++;
852
 
759 palkovsky 853
        cache = list_get_instance(cur, slab_cache_t, link);
3183 jermar 854
 
855
        char *name = cache->name;
856
        uint8_t order = cache->order;
857
        size_t size = cache->size;
858
        unsigned int objects = cache->objects;
859
        long allocated_slabs = atomic_get(&cache->allocated_slabs);
860
        long cached_objs = atomic_get(&cache->cached_objs);
861
        long allocated_objs = atomic_get(&cache->allocated_objs);
862
        int flags = cache->flags;
2052 decky 863
 
3183 jermar 864
        spinlock_unlock(&slab_cache_lock);
865
        interrupts_restore(ipl);
866
 
3057 decky 867
        printf("%-16s %8" PRIs " %6d %6u %6ld %6ld %9ld %-3s\n",
3183 jermar 868
            name, size, (1 << order), objects, allocated_slabs,
869
            cached_objs, allocated_objs,
870
            flags & SLAB_CACHE_SLINSIDE ? "in" : "out");
759 palkovsky 871
    }
872
}
873
 
874
void slab_cache_init(void)
875
{
771 palkovsky 876
    int i, size;
877
 
759 palkovsky 878
    /* Initialize magazine cache */
3180 jermar 879
    _slab_cache_create(&mag_cache, "slab_magazine",
880
        sizeof(slab_magazine_t) + SLAB_MAG_SIZE * sizeof(void*),
881
        sizeof(uintptr_t), NULL, NULL, SLAB_CACHE_NOMAGAZINE |
882
        SLAB_CACHE_SLINSIDE);
769 palkovsky 883
    /* Initialize slab_cache cache */
3180 jermar 884
    _slab_cache_create(&slab_cache_cache, "slab_cache",
885
        sizeof(slab_cache_cache), sizeof(uintptr_t), NULL, NULL,
886
        SLAB_CACHE_NOMAGAZINE | SLAB_CACHE_SLINSIDE);
769 palkovsky 887
    /* Initialize external slab cache */
3180 jermar 888
    slab_extern_cache = slab_cache_create("slab_extern", sizeof(slab_t), 0,
889
        NULL, NULL, SLAB_CACHE_SLINSIDE | SLAB_CACHE_MAGDEFERRED);
759 palkovsky 890
 
891
    /* Initialize structures for malloc */
3180 jermar 892
    for (i = 0, size = (1 << SLAB_MIN_MALLOC_W);
893
        i < (SLAB_MAX_MALLOC_W - SLAB_MIN_MALLOC_W + 1);
894
        i++, size <<= 1) {
895
        malloc_caches[i] = slab_cache_create(malloc_names[i], size, 0,
896
            NULL, NULL, SLAB_CACHE_MAGDEFERRED);
771 palkovsky 897
    }
778 palkovsky 898
#ifdef CONFIG_DEBUG       
899
    _slab_initialized = 1;
900
#endif
759 palkovsky 901
}
771 palkovsky 902
 
789 palkovsky 903
/** Enable cpu_cache
904
 *
905
 * Kernel calls this function, when it knows the real number of
906
 * processors.
907
 * Allocate slab for cpucache and enable it on all existing
908
 * slabs that are SLAB_CACHE_MAGDEFERRED
909
 */
910
void slab_enable_cpucache(void)
911
{
912
    link_t *cur;
913
    slab_cache_t *s;
914
 
791 palkovsky 915
#ifdef CONFIG_DEBUG
916
    _slab_initialized = 2;
917
#endif
918
 
789 palkovsky 919
    spinlock_lock(&slab_cache_lock);
920
 
3180 jermar 921
    for (cur = slab_cache_list.next; cur != &slab_cache_list;
922
        cur = cur->next){
789 palkovsky 923
        s = list_get_instance(cur, slab_cache_t, link);
3180 jermar 924
        if ((s->flags & SLAB_CACHE_MAGDEFERRED) !=
925
            SLAB_CACHE_MAGDEFERRED)
789 palkovsky 926
            continue;
927
        make_magcache(s);
928
        s->flags &= ~SLAB_CACHE_MAGDEFERRED;
929
    }
930
 
931
    spinlock_unlock(&slab_cache_lock);
932
}
933
 
771 palkovsky 934
/**************************************/
935
/* kalloc/kfree functions             */
3180 jermar 936
void *malloc(unsigned int size, int flags)
771 palkovsky 937
{
778 palkovsky 938
    ASSERT(_slab_initialized);
4303 jermar 939
    ASSERT(size <= (1 << SLAB_MAX_MALLOC_W));
771 palkovsky 940
 
941
    if (size < (1 << SLAB_MIN_MALLOC_W))
942
        size = (1 << SLAB_MIN_MALLOC_W);
943
 
2124 decky 944
    int idx = fnzb(size - 1) - SLAB_MIN_MALLOC_W + 1;
771 palkovsky 945
 
946
    return slab_alloc(malloc_caches[idx], flags);
947
}
948
 
3180 jermar 949
void *realloc(void *ptr, unsigned int size, int flags)
771 palkovsky 950
{
2124 decky 951
    ASSERT(_slab_initialized);
952
    ASSERT(size <= (1 << SLAB_MAX_MALLOC_W));
953
 
954
    void *new_ptr;
955
 
956
    if (size > 0) {
957
        if (size < (1 << SLAB_MIN_MALLOC_W))
958
            size = (1 << SLAB_MIN_MALLOC_W);
959
        int idx = fnzb(size - 1) - SLAB_MIN_MALLOC_W + 1;
960
 
961
        new_ptr = slab_alloc(malloc_caches[idx], flags);
962
    } else
963
        new_ptr = NULL;
964
 
965
    if ((new_ptr != NULL) && (ptr != NULL)) {
966
        slab_t *slab = obj2slab(ptr);
967
        memcpy(new_ptr, ptr, min(size, slab->cache->size));
968
    }
969
 
970
    if (ptr != NULL)
971
        free(ptr);
972
 
973
    return new_ptr;
974
}
781 palkovsky 975
 
2124 decky 976
void free(void *ptr)
977
{
978
    if (!ptr)
1950 jermar 979
        return;
781 palkovsky 980
 
2124 decky 981
    slab_t *slab = obj2slab(ptr);
982
    _slab_free(slab->cache, ptr, slab);
771 palkovsky 983
}
1702 cejka 984
 
1757 jermar 985
/** @}
1702 cejka 986
 */