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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];
771 palkovsky 132
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",
147
    "malloc-256K"
771 palkovsky 148
};
762 palkovsky 149
 
769 palkovsky 150
/** Slab descriptor */
762 palkovsky 151
typedef struct {
1950 jermar 152
    slab_cache_t *cache;    /**< Pointer to parent cache. */
153
    link_t link;        /**< List of full/partial slabs. */
154
    void *start;        /**< Start address of first available item. */
155
    count_t available;  /**< Count of available items in this slab. */
156
    index_t nextavail;  /**< The index of next available item. */
2124 decky 157
} slab_t;
762 palkovsky 158
 
791 palkovsky 159
#ifdef CONFIG_DEBUG
160
static int _slab_initialized = 0;
161
#endif
162
 
759 palkovsky 163
/**************************************/
1248 jermar 164
/* Slab allocation functions          */
759 palkovsky 165
 
762 palkovsky 166
/**
167
 * Allocate frames for slab space and initialize
168
 *
169
 */
170
static slab_t * slab_space_alloc(slab_cache_t *cache, int flags)
171
{
172
    void *data;
173
    slab_t *slab;
174
    size_t fsize;
2745 decky 175
    unsigned int i;
2123 decky 176
    unsigned int zone = 0;
814 palkovsky 177
 
1766 palkovsky 178
    data = frame_alloc_generic(cache->order, FRAME_KA | flags, &zone);
179
    if (!data) {
762 palkovsky 180
        return NULL;
764 palkovsky 181
    }
768 palkovsky 182
    if (! (cache->flags & SLAB_CACHE_SLINSIDE)) {
769 palkovsky 183
        slab = slab_alloc(slab_extern_cache, flags);
762 palkovsky 184
        if (!slab) {
1760 palkovsky 185
            frame_free(KA2PA(data));
762 palkovsky 186
            return NULL;
187
        }
188
    } else {
189
        fsize = (PAGE_SIZE << cache->order);
190
        slab = data + fsize - sizeof(*slab);
191
    }
1288 jermar 192
 
762 palkovsky 193
    /* Fill in slab structures */
2745 decky 194
    for (i = 0; i < ((unsigned int) 1 << cache->order); i++)
195
        frame_set_parent(ADDR2PFN(KA2PA(data)) + i, slab, zone);
762 palkovsky 196
 
197
    slab->start = data;
198
    slab->available = cache->objects;
199
    slab->nextavail = 0;
767 palkovsky 200
    slab->cache = cache;
762 palkovsky 201
 
2745 decky 202
    for (i = 0; i < cache->objects; i++)
762 palkovsky 203
        *((int *) (slab->start + i*cache->size)) = i+1;
764 palkovsky 204
 
205
    atomic_inc(&cache->allocated_slabs);
762 palkovsky 206
    return slab;
207
}
208
 
759 palkovsky 209
/**
1248 jermar 210
 * Deallocate space associated with slab
762 palkovsky 211
 *
212
 * @return number of freed frames
213
 */
214
static count_t slab_space_free(slab_cache_t *cache, slab_t *slab)
215
{
1760 palkovsky 216
    frame_free(KA2PA(slab->start));
768 palkovsky 217
    if (! (cache->flags & SLAB_CACHE_SLINSIDE))
769 palkovsky 218
        slab_free(slab_extern_cache, slab);
764 palkovsky 219
 
220
    atomic_dec(&cache->allocated_slabs);
221
 
762 palkovsky 222
    return 1 << cache->order;
223
}
224
 
225
/** Map object to slab structure */
226
static slab_t * obj2slab(void *obj)
227
{
2124 decky 228
    return (slab_t *) frame_get_parent(ADDR2PFN(KA2PA(obj)), 0);
762 palkovsky 229
}
230
 
231
/**************************************/
1248 jermar 232
/* Slab functions */
762 palkovsky 233
 
234
 
235
/**
759 palkovsky 236
 * Return object to slab and call a destructor
237
 *
762 palkovsky 238
 * @param slab If the caller knows directly slab of the object, otherwise NULL
239
 *
759 palkovsky 240
 * @return Number of freed pages
241
 */
762 palkovsky 242
static count_t slab_obj_destroy(slab_cache_t *cache, void *obj,
243
                slab_t *slab)
759 palkovsky 244
{
787 palkovsky 245
    int freed = 0;
246
 
762 palkovsky 247
    if (!slab)
248
        slab = obj2slab(obj);
249
 
767 palkovsky 250
    ASSERT(slab->cache == cache);
251
 
787 palkovsky 252
    if (cache->destructor)
253
        freed = cache->destructor(obj);
254
 
776 palkovsky 255
    spinlock_lock(&cache->slablock);
789 palkovsky 256
    ASSERT(slab->available < cache->objects);
776 palkovsky 257
 
762 palkovsky 258
    *((int *)obj) = slab->nextavail;
259
    slab->nextavail = (obj - slab->start)/cache->size;
260
    slab->available++;
261
 
262
    /* Move it to correct list */
263
    if (slab->available == cache->objects) {
264
        /* Free associated memory */
265
        list_remove(&slab->link);
782 palkovsky 266
        spinlock_unlock(&cache->slablock);
267
 
787 palkovsky 268
        return freed + slab_space_free(cache, slab);
782 palkovsky 269
 
780 palkovsky 270
    } else if (slab->available == 1) {
271
        /* It was in full, move to partial */
272
        list_remove(&slab->link);
273
        list_prepend(&slab->link, &cache->partial_slabs);
762 palkovsky 274
    }
783 palkovsky 275
    spinlock_unlock(&cache->slablock);
787 palkovsky 276
    return freed;
759 palkovsky 277
}
278
 
279
/**
280
 * Take new object from slab or create new if needed
281
 *
282
 * @return Object address or null
283
 */
284
static void * slab_obj_create(slab_cache_t *cache, int flags)
285
{
762 palkovsky 286
    slab_t *slab;
287
    void *obj;
288
 
776 palkovsky 289
    spinlock_lock(&cache->slablock);
290
 
762 palkovsky 291
    if (list_empty(&cache->partial_slabs)) {
292
        /* Allow recursion and reclaiming
1248 jermar 293
         * - this should work, as the slab control structures
1288 jermar 294
         *   are small and do not need to allocate with anything
295
         *   other than frame_alloc when they are allocating,
762 palkovsky 296
         *   that's why we should get recursion at most 1-level deep
297
         */
776 palkovsky 298
        spinlock_unlock(&cache->slablock);
762 palkovsky 299
        slab = slab_space_alloc(cache, flags);
780 palkovsky 300
        if (!slab)
301
            return NULL;
776 palkovsky 302
        spinlock_lock(&cache->slablock);
762 palkovsky 303
    } else {
1950 jermar 304
        slab = list_get_instance(cache->partial_slabs.next, slab_t, link);
762 palkovsky 305
        list_remove(&slab->link);
306
    }
307
    obj = slab->start + slab->nextavail * cache->size;
308
    slab->nextavail = *((int *)obj);
309
    slab->available--;
787 palkovsky 310
 
1950 jermar 311
    if (!slab->available)
764 palkovsky 312
        list_prepend(&slab->link, &cache->full_slabs);
762 palkovsky 313
    else
764 palkovsky 314
        list_prepend(&slab->link, &cache->partial_slabs);
776 palkovsky 315
 
316
    spinlock_unlock(&cache->slablock);
787 palkovsky 317
 
318
    if (cache->constructor && cache->constructor(obj, flags)) {
319
        /* Bad, bad, construction failed */
320
        slab_obj_destroy(cache, obj, slab);
321
        return NULL;
322
    }
762 palkovsky 323
    return obj;
759 palkovsky 324
}
325
 
326
/**************************************/
327
/* CPU-Cache slab functions */
328
 
329
/**
781 palkovsky 330
 * Finds a full magazine in cache, takes it from list
331
 * and returns it
332
 *
333
 * @param first If true, return first, else last mag
334
 */
335
static slab_magazine_t * get_mag_from_cache(slab_cache_t *cache,
336
                        int first)
337
{
338
    slab_magazine_t *mag = NULL;
339
    link_t *cur;
340
 
341
    spinlock_lock(&cache->maglock);
342
    if (!list_empty(&cache->magazines)) {
343
        if (first)
344
            cur = cache->magazines.next;
345
        else
346
            cur = cache->magazines.prev;
347
        mag = list_get_instance(cur, slab_magazine_t, link);
348
        list_remove(&mag->link);
349
        atomic_dec(&cache->magazine_counter);
350
    }
351
    spinlock_unlock(&cache->maglock);
352
    return mag;
353
}
354
 
355
/** Prepend magazine to magazine list in cache */
356
static void put_mag_to_cache(slab_cache_t *cache, slab_magazine_t *mag)
357
{
358
    spinlock_lock(&cache->maglock);
359
 
360
    list_prepend(&mag->link, &cache->magazines);
361
    atomic_inc(&cache->magazine_counter);
362
 
363
    spinlock_unlock(&cache->maglock);
364
}
365
 
366
/**
759 palkovsky 367
 * Free all objects in magazine and free memory associated with magazine
368
 *
369
 * @return Number of freed pages
370
 */
371
static count_t magazine_destroy(slab_cache_t *cache,
372
                slab_magazine_t *mag)
373
{
2745 decky 374
    unsigned int i;
759 palkovsky 375
    count_t frames = 0;
376
 
2745 decky 377
    for (i = 0; i < mag->busy; i++) {
762 palkovsky 378
        frames += slab_obj_destroy(cache, mag->objs[i], NULL);
767 palkovsky 379
        atomic_dec(&cache->cached_objs);
380
    }
759 palkovsky 381
 
382
    slab_free(&mag_cache, mag);
383
 
384
    return frames;
385
}
386
 
387
/**
769 palkovsky 388
 * Find full magazine, set it as current and return it
389
 *
390
 * Assume cpu_magazine lock is held
391
 */
392
static slab_magazine_t * get_full_current_mag(slab_cache_t *cache)
393
{
394
    slab_magazine_t *cmag, *lastmag, *newmag;
395
 
396
    cmag = cache->mag_cache[CPU->id].current;
397
    lastmag = cache->mag_cache[CPU->id].last;
398
    if (cmag) { /* First try local CPU magazines */
399
        if (cmag->busy)
400
            return cmag;
401
 
402
        if (lastmag && lastmag->busy) {
403
            cache->mag_cache[CPU->id].current = lastmag;
404
            cache->mag_cache[CPU->id].last = cmag;
405
            return lastmag;
406
        }
407
    }
408
    /* Local magazines are empty, import one from magazine list */
781 palkovsky 409
    newmag = get_mag_from_cache(cache, 1);
410
    if (!newmag)
769 palkovsky 411
        return NULL;
412
 
413
    if (lastmag)
781 palkovsky 414
        magazine_destroy(cache, lastmag);
415
 
769 palkovsky 416
    cache->mag_cache[CPU->id].last = cmag;
417
    cache->mag_cache[CPU->id].current = newmag;
418
    return newmag;
419
}
420
 
421
/**
759 palkovsky 422
 * Try to find object in CPU-cache magazines
423
 *
424
 * @return Pointer to object or NULL if not available
425
 */
426
static void * magazine_obj_get(slab_cache_t *cache)
427
{
428
    slab_magazine_t *mag;
767 palkovsky 429
    void *obj;
759 palkovsky 430
 
772 palkovsky 431
    if (!CPU)
432
        return NULL;
433
 
759 palkovsky 434
    spinlock_lock(&cache->mag_cache[CPU->id].lock);
435
 
769 palkovsky 436
    mag = get_full_current_mag(cache);
437
    if (!mag) {
438
        spinlock_unlock(&cache->mag_cache[CPU->id].lock);
439
        return NULL;
759 palkovsky 440
    }
767 palkovsky 441
    obj = mag->objs[--mag->busy];
759 palkovsky 442
    spinlock_unlock(&cache->mag_cache[CPU->id].lock);
767 palkovsky 443
    atomic_dec(&cache->cached_objs);
444
 
445
    return obj;
759 palkovsky 446
}
447
 
448
/**
768 palkovsky 449
 * Assure that the current magazine is empty, return pointer to it, or NULL if
769 palkovsky 450
 * no empty magazine is available and cannot be allocated
759 palkovsky 451
 *
773 palkovsky 452
 * Assume mag_cache[CPU->id].lock is held
453
 *
759 palkovsky 454
 * We have 2 magazines bound to processor.
455
 * First try the current.
456
 *  If full, try the last.
457
 *   If full, put to magazines list.
458
 *   allocate new, exchange last & current
459
 *
768 palkovsky 460
 */
461
static slab_magazine_t * make_empty_current_mag(slab_cache_t *cache)
462
{
463
    slab_magazine_t *cmag,*lastmag,*newmag;
464
 
465
    cmag = cache->mag_cache[CPU->id].current;
466
    lastmag = cache->mag_cache[CPU->id].last;
467
 
468
    if (cmag) {
469
        if (cmag->busy < cmag->size)
470
            return cmag;
471
        if (lastmag && lastmag->busy < lastmag->size) {
472
            cache->mag_cache[CPU->id].last = cmag;
473
            cache->mag_cache[CPU->id].current = lastmag;
474
            return lastmag;
475
        }
476
    }
477
    /* current | last are full | nonexistent, allocate new */
478
    /* We do not want to sleep just because of caching */
479
    /* Especially we do not want reclaiming to start, as
480
     * this would deadlock */
481
    newmag = slab_alloc(&mag_cache, FRAME_ATOMIC | FRAME_NO_RECLAIM);
482
    if (!newmag)
483
        return NULL;
484
    newmag->size = SLAB_MAG_SIZE;
485
    newmag->busy = 0;
486
 
487
    /* Flush last to magazine list */
781 palkovsky 488
    if (lastmag)
489
        put_mag_to_cache(cache, lastmag);
490
 
768 palkovsky 491
    /* Move current as last, save new as current */
492
    cache->mag_cache[CPU->id].last = cmag; 
493
    cache->mag_cache[CPU->id].current = newmag;
494
 
495
    return newmag;
496
}
497
 
498
/**
499
 * Put object into CPU-cache magazine
500
 *
759 palkovsky 501
 * @return 0 - success, -1 - could not get memory
502
 */
503
static int magazine_obj_put(slab_cache_t *cache, void *obj)
504
{
505
    slab_magazine_t *mag;
506
 
772 palkovsky 507
    if (!CPU)
508
        return -1;
509
 
759 palkovsky 510
    spinlock_lock(&cache->mag_cache[CPU->id].lock);
768 palkovsky 511
 
512
    mag = make_empty_current_mag(cache);
769 palkovsky 513
    if (!mag) {
514
        spinlock_unlock(&cache->mag_cache[CPU->id].lock);
515
        return -1;
516
    }
759 palkovsky 517
 
518
    mag->objs[mag->busy++] = obj;
519
 
520
    spinlock_unlock(&cache->mag_cache[CPU->id].lock);
767 palkovsky 521
    atomic_inc(&cache->cached_objs);
759 palkovsky 522
    return 0;
523
}
524
 
525
 
526
/**************************************/
1248 jermar 527
/* Slab cache functions */
759 palkovsky 528
 
762 palkovsky 529
/** Return number of objects that fit in certain cache size */
2745 decky 530
static unsigned int comp_objects(slab_cache_t *cache)
762 palkovsky 531
{
532
    if (cache->flags & SLAB_CACHE_SLINSIDE)
533
        return ((PAGE_SIZE << cache->order) - sizeof(slab_t)) / cache->size;
534
    else
535
        return (PAGE_SIZE << cache->order) / cache->size;
536
}
537
 
538
/** Return wasted space in slab */
2745 decky 539
static unsigned int badness(slab_cache_t *cache)
762 palkovsky 540
{
2745 decky 541
    unsigned int objects;
542
    unsigned int ssize;
762 palkovsky 543
 
544
    objects = comp_objects(cache);
545
    ssize = PAGE_SIZE << cache->order;
546
    if (cache->flags & SLAB_CACHE_SLINSIDE)
547
        ssize -= sizeof(slab_t);
2745 decky 548
    return ssize - objects * cache->size;
762 palkovsky 549
}
550
 
789 palkovsky 551
/**
552
 * Initialize mag_cache structure in slab cache
553
 */
554
static void make_magcache(slab_cache_t *cache)
555
{
2745 decky 556
    unsigned int i;
791 palkovsky 557
 
558
    ASSERT(_slab_initialized >= 2);
789 palkovsky 559
 
822 palkovsky 560
    cache->mag_cache = malloc(sizeof(slab_mag_cache_t)*config.cpu_count,0);
2745 decky 561
    for (i = 0; i < config.cpu_count; i++) {
1780 jermar 562
        memsetb((uintptr_t)&cache->mag_cache[i],
789 palkovsky 563
            sizeof(cache->mag_cache[i]), 0);
2745 decky 564
        spinlock_initialize(&cache->mag_cache[i].lock, "slab_maglock_cpu");
789 palkovsky 565
    }
566
}
567
 
759 palkovsky 568
/** Initialize allocated memory as a slab cache */
569
static void
570
_slab_cache_create(slab_cache_t *cache,
571
           char *name,
572
           size_t size,
573
           size_t align,
574
           int (*constructor)(void *obj, int kmflag),
787 palkovsky 575
           int (*destructor)(void *obj),
759 palkovsky 576
           int flags)
577
{
771 palkovsky 578
    int pages;
783 palkovsky 579
    ipl_t ipl;
759 palkovsky 580
 
1780 jermar 581
    memsetb((uintptr_t)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");
789 palkovsky 599
    if (! (cache->flags & SLAB_CACHE_NOMAGAZINE))
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
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  */
633
slab_cache_t * slab_cache_create(char *name,
634
                 size_t size,
635
                 size_t align,
636
                 int (*constructor)(void *obj, int kmflag),
787 palkovsky 637
                 int (*destructor)(void *obj),
759 palkovsky 638
                 int flags)
639
{
640
    slab_cache_t *cache;
641
 
769 palkovsky 642
    cache = slab_alloc(&slab_cache_cache, 0);
759 palkovsky 643
    _slab_cache_create(cache, name, size, align, constructor, destructor,
644
               flags);
645
    return cache;
646
}
647
 
648
/**
649
 * Reclaim space occupied by objects that are already free
650
 *
651
 * @param flags If contains SLAB_RECLAIM_ALL, do aggressive freeing
652
 * @return Number of freed pages
653
 */
654
static count_t _slab_reclaim(slab_cache_t *cache, int flags)
655
{
2745 decky 656
    unsigned int i;
759 palkovsky 657
    slab_magazine_t *mag;
658
    count_t frames = 0;
781 palkovsky 659
    int magcount;
759 palkovsky 660
 
661
    if (cache->flags & SLAB_CACHE_NOMAGAZINE)
662
        return 0; /* Nothing to do */
781 palkovsky 663
 
664
    /* We count up to original magazine count to avoid
665
     * endless loop
666
     */
667
    magcount = atomic_get(&cache->magazine_counter);
668
    while (magcount-- && (mag=get_mag_from_cache(cache,0))) {
669
        frames += magazine_destroy(cache,mag);
670
        if (!(flags & SLAB_RECLAIM_ALL) && frames)
671
            break;
769 palkovsky 672
    }
759 palkovsky 673
 
674
    if (flags & SLAB_RECLAIM_ALL) {
781 palkovsky 675
        /* Free cpu-bound magazines */
759 palkovsky 676
        /* Destroy CPU magazines */
2745 decky 677
        for (i = 0; i < config.cpu_count; i++) {
781 palkovsky 678
            spinlock_lock(&cache->mag_cache[i].lock);
679
 
759 palkovsky 680
            mag = cache->mag_cache[i].current;
681
            if (mag)
682
                frames += magazine_destroy(cache, mag);
683
            cache->mag_cache[i].current = NULL;
684
 
685
            mag = cache->mag_cache[i].last;
686
            if (mag)
687
                frames += magazine_destroy(cache, mag);
688
            cache->mag_cache[i].last = NULL;
781 palkovsky 689
 
690
            spinlock_unlock(&cache->mag_cache[i].lock);
759 palkovsky 691
        }
692
    }
767 palkovsky 693
 
759 palkovsky 694
    return frames;
695
}
696
 
697
/** Check that there are no slabs and remove cache from system  */
698
void slab_cache_destroy(slab_cache_t *cache)
699
{
781 palkovsky 700
    ipl_t ipl;
701
 
702
    /* First remove cache from link, so that we don't need
703
     * to disable interrupts later
704
     */
705
 
706
    ipl = interrupts_disable();
707
    spinlock_lock(&slab_cache_lock);
708
 
709
    list_remove(&cache->link);
710
 
711
    spinlock_unlock(&slab_cache_lock);
712
    interrupts_restore(ipl);
713
 
759 palkovsky 714
    /* Do not lock anything, we assume the software is correct and
715
     * does not touch the cache when it decides to destroy it */
716
 
717
    /* Destroy all magazines */
718
    _slab_reclaim(cache, SLAB_RECLAIM_ALL);
719
 
720
    /* All slabs must be empty */
721
    if (!list_empty(&cache->full_slabs) \
722
        || !list_empty(&cache->partial_slabs))
723
        panic("Destroying cache that is not empty.");
724
 
789 palkovsky 725
    if (!(cache->flags & SLAB_CACHE_NOMAGAZINE))
822 palkovsky 726
        free(cache->mag_cache);
769 palkovsky 727
    slab_free(&slab_cache_cache, cache);
759 palkovsky 728
}
729
 
730
/** Allocate new object from cache - if no flags given, always returns
731
    memory */
732
void * slab_alloc(slab_cache_t *cache, int flags)
733
{
734
    ipl_t ipl;
735
    void *result = NULL;
773 palkovsky 736
 
759 palkovsky 737
    /* Disable interrupts to avoid deadlocks with interrupt handlers */
738
    ipl = interrupts_disable();
771 palkovsky 739
 
814 palkovsky 740
    if (!(cache->flags & SLAB_CACHE_NOMAGAZINE)) {
759 palkovsky 741
        result = magazine_obj_get(cache);
814 palkovsky 742
    }
776 palkovsky 743
    if (!result)
759 palkovsky 744
        result = slab_obj_create(cache, flags);
745
 
769 palkovsky 746
    interrupts_restore(ipl);
747
 
764 palkovsky 748
    if (result)
749
        atomic_inc(&cache->allocated_objs);
750
 
759 palkovsky 751
    return result;
752
}
753
 
771 palkovsky 754
/** Return object to cache, use slab if known  */
755
static void _slab_free(slab_cache_t *cache, void *obj, slab_t *slab)
759 palkovsky 756
{
757
    ipl_t ipl;
758
 
759
    ipl = interrupts_disable();
760
 
762 palkovsky 761
    if ((cache->flags & SLAB_CACHE_NOMAGAZINE) \
762
        || magazine_obj_put(cache, obj)) {
776 palkovsky 763
 
771 palkovsky 764
        slab_obj_destroy(cache, obj, slab);
776 palkovsky 765
 
759 palkovsky 766
    }
769 palkovsky 767
    interrupts_restore(ipl);
764 palkovsky 768
    atomic_dec(&cache->allocated_objs);
759 palkovsky 769
}
770
 
771 palkovsky 771
/** Return slab object to cache */
772
void slab_free(slab_cache_t *cache, void *obj)
773
{
2124 decky 774
    _slab_free(cache, obj, NULL);
771 palkovsky 775
}
776
 
759 palkovsky 777
/* Go through all caches and reclaim what is possible */
778
count_t slab_reclaim(int flags)
779
{
780
    slab_cache_t *cache;
781
    link_t *cur;
782
    count_t frames = 0;
783
 
784
    spinlock_lock(&slab_cache_lock);
785
 
776 palkovsky 786
    /* TODO: Add assert, that interrupts are disabled, otherwise
787
     * memory allocation from interrupts can deadlock.
788
     */
789
 
759 palkovsky 790
    for (cur = slab_cache_list.next;cur!=&slab_cache_list; cur=cur->next) {
791
        cache = list_get_instance(cur, slab_cache_t, link);
792
        frames += _slab_reclaim(cache, flags);
793
    }
794
 
795
    spinlock_unlock(&slab_cache_lock);
796
 
797
    return frames;
798
}
799
 
800
 
801
/* Print list of slabs */
802
void slab_print_list(void)
803
{
804
    slab_cache_t *cache;
805
    link_t *cur;
783 palkovsky 806
    ipl_t ipl;
807
 
808
    ipl = interrupts_disable();
759 palkovsky 809
    spinlock_lock(&slab_cache_lock);
2052 decky 810
    printf("slab name        size     pages  obj/pg slabs  cached allocated ctl\n");
811
    printf("---------------- -------- ------ ------ ------ ------ --------- ---\n");
812
 
813
    for (cur = slab_cache_list.next; cur != &slab_cache_list; cur = cur->next) {
759 palkovsky 814
        cache = list_get_instance(cur, slab_cache_t, link);
2052 decky 815
 
816
        printf("%-16s %8zd %6zd %6zd %6zd %6zd %9zd %-3s\n", cache->name, cache->size, (1 << cache->order), cache->objects, atomic_get(&cache->allocated_slabs), atomic_get(&cache->cached_objs), atomic_get(&cache->allocated_objs), cache->flags & SLAB_CACHE_SLINSIDE ? "in" : "out");
759 palkovsky 817
    }
818
    spinlock_unlock(&slab_cache_lock);
783 palkovsky 819
    interrupts_restore(ipl);
759 palkovsky 820
}
821
 
822
void slab_cache_init(void)
823
{
771 palkovsky 824
    int i, size;
825
 
759 palkovsky 826
    /* Initialize magazine cache */
827
    _slab_cache_create(&mag_cache,
828
               "slab_magazine",
829
               sizeof(slab_magazine_t)+SLAB_MAG_SIZE*sizeof(void*),
1780 jermar 830
               sizeof(uintptr_t),
759 palkovsky 831
               NULL, NULL,
769 palkovsky 832
               SLAB_CACHE_NOMAGAZINE | SLAB_CACHE_SLINSIDE);
833
    /* Initialize slab_cache cache */
834
    _slab_cache_create(&slab_cache_cache,
835
               "slab_cache",
789 palkovsky 836
               sizeof(slab_cache_cache),
1780 jermar 837
               sizeof(uintptr_t),
769 palkovsky 838
               NULL, NULL,
839
               SLAB_CACHE_NOMAGAZINE | SLAB_CACHE_SLINSIDE);
840
    /* Initialize external slab cache */
841
    slab_extern_cache = slab_cache_create("slab_extern",
842
                          sizeof(slab_t),
843
                          0, NULL, NULL,
789 palkovsky 844
                          SLAB_CACHE_SLINSIDE | SLAB_CACHE_MAGDEFERRED);
759 palkovsky 845
 
846
    /* Initialize structures for malloc */
771 palkovsky 847
    for (i=0, size=(1<<SLAB_MIN_MALLOC_W);
848
         i < (SLAB_MAX_MALLOC_W-SLAB_MIN_MALLOC_W+1);
849
         i++, size <<= 1) {
850
        malloc_caches[i] = slab_cache_create(malloc_names[i],
851
                             size, 0,
789 palkovsky 852
                             NULL,NULL, SLAB_CACHE_MAGDEFERRED);
771 palkovsky 853
    }
778 palkovsky 854
#ifdef CONFIG_DEBUG       
855
    _slab_initialized = 1;
856
#endif
759 palkovsky 857
}
771 palkovsky 858
 
789 palkovsky 859
/** Enable cpu_cache
860
 *
861
 * Kernel calls this function, when it knows the real number of
862
 * processors.
863
 * Allocate slab for cpucache and enable it on all existing
864
 * slabs that are SLAB_CACHE_MAGDEFERRED
865
 */
866
void slab_enable_cpucache(void)
867
{
868
    link_t *cur;
869
    slab_cache_t *s;
870
 
791 palkovsky 871
#ifdef CONFIG_DEBUG
872
    _slab_initialized = 2;
873
#endif
874
 
789 palkovsky 875
    spinlock_lock(&slab_cache_lock);
876
 
877
    for (cur=slab_cache_list.next; cur != &slab_cache_list;cur=cur->next){
878
        s = list_get_instance(cur, slab_cache_t, link);
879
        if ((s->flags & SLAB_CACHE_MAGDEFERRED) != SLAB_CACHE_MAGDEFERRED)
880
            continue;
881
        make_magcache(s);
882
        s->flags &= ~SLAB_CACHE_MAGDEFERRED;
883
    }
884
 
885
    spinlock_unlock(&slab_cache_lock);
886
}
887
 
771 palkovsky 888
/**************************************/
889
/* kalloc/kfree functions             */
822 palkovsky 890
void * malloc(unsigned int size, int flags)
771 palkovsky 891
{
778 palkovsky 892
    ASSERT(_slab_initialized);
1288 jermar 893
    ASSERT(size && size <= (1 << SLAB_MAX_MALLOC_W));
771 palkovsky 894
 
895
    if (size < (1 << SLAB_MIN_MALLOC_W))
896
        size = (1 << SLAB_MIN_MALLOC_W);
897
 
2124 decky 898
    int idx = fnzb(size - 1) - SLAB_MIN_MALLOC_W + 1;
771 palkovsky 899
 
900
    return slab_alloc(malloc_caches[idx], flags);
901
}
902
 
2124 decky 903
void * realloc(void *ptr, unsigned int size, int flags)
771 palkovsky 904
{
2124 decky 905
    ASSERT(_slab_initialized);
906
    ASSERT(size <= (1 << SLAB_MAX_MALLOC_W));
907
 
908
    void *new_ptr;
909
 
910
    if (size > 0) {
911
        if (size < (1 << SLAB_MIN_MALLOC_W))
912
            size = (1 << SLAB_MIN_MALLOC_W);
913
        int idx = fnzb(size - 1) - SLAB_MIN_MALLOC_W + 1;
914
 
915
        new_ptr = slab_alloc(malloc_caches[idx], flags);
916
    } else
917
        new_ptr = NULL;
918
 
919
    if ((new_ptr != NULL) && (ptr != NULL)) {
920
        slab_t *slab = obj2slab(ptr);
921
        memcpy(new_ptr, ptr, min(size, slab->cache->size));
922
    }
923
 
924
    if (ptr != NULL)
925
        free(ptr);
926
 
927
    return new_ptr;
928
}
781 palkovsky 929
 
2124 decky 930
void free(void *ptr)
931
{
932
    if (!ptr)
1950 jermar 933
        return;
781 palkovsky 934
 
2124 decky 935
    slab_t *slab = obj2slab(ptr);
936
    _slab_free(slab->cache, ptr, slab);
771 palkovsky 937
}
1702 cejka 938
 
1757 jermar 939
/** @}
1702 cejka 940
 */