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  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.  
  29. /*
  30.  * The SLAB allocator is closely modelled after Opensolaris SLAB allocator
  31.  * http://www.usenix.org/events/usenix01/full_papers/bonwick/bonwick_html/
  32.  *
  33.  * with the following exceptions:
  34.  *   - empty SLABS are deallocated immediately
  35.  *     (in Linux they are kept in linked list, in Solaris ???)
  36.  *   - empty magazines are deallocated when not needed
  37.  *     (in Solaris they are held in linked list in slab cache)
  38.  *
  39.  *   Following features are not currently supported but would be easy to do:
  40.  *   - cache coloring
  41.  *   - dynamic magazine growing (different magazine sizes are already
  42.  *     supported, but we would need to adjust allocating strategy)
  43.  *
  44.  * The SLAB allocator supports per-CPU caches ('magazines') to facilitate
  45.  * good SMP scaling.
  46.  *
  47.  * When a new object is being allocated, it is first checked, if it is
  48.  * available in CPU-bound magazine. If it is not found there, it is
  49.  * allocated from CPU-shared SLAB - if partial full is found, it is used,
  50.  * otherwise a new one is allocated.
  51.  *
  52.  * When an object is being deallocated, it is put to CPU-bound magazine.
  53.  * If there is no such magazine, new one is allocated (if it fails,
  54.  * the object is deallocated into SLAB). If the magazine is full, it is
  55.  * put into cpu-shared list of magazines and new one is allocated.
  56.  *
  57.  * The CPU-bound magazine is actually a pair of magazine to avoid
  58.  * thrashing when somebody is allocating/deallocating 1 item at the magazine
  59.  * size boundary. LIFO order is enforced, which should avoid fragmentation
  60.  * as much as possible.
  61.  *  
  62.  * Every cache contains list of full slabs and list of partialy full slabs.
  63.  * Empty SLABS are immediately freed (thrashing will be avoided because
  64.  * of magazines).
  65.  *
  66.  * The SLAB information structure is kept inside the data area, if possible.
  67.  * The cache can be marked that it should not use magazines. This is used
  68.  * only for SLAB related caches to avoid deadlocks and infinite recursion
  69.  * (the SLAB allocator uses itself for allocating all it's control structures).
  70.  *
  71.  * The SLAB allocator allocates lot of space and does not free it. When
  72.  * frame allocator fails to allocate the frame, it calls slab_reclaim().
  73.  * It tries 'light reclaim' first, then brutal reclaim. The light reclaim
  74.  * releases slabs from cpu-shared magazine-list, until at least 1 slab
  75.  * is deallocated in each cache (this algorithm should probably change).
  76.  * The brutal reclaim removes all cached objects, even from CPU-bound
  77.  * magazines.
  78.  *
  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.  *
  88.  */
  89.  
  90.  
  91. #include <synch/spinlock.h>
  92. #include <mm/slab.h>
  93. #include <list.h>
  94. #include <memstr.h>
  95. #include <align.h>
  96. #include <mm/heap.h>
  97. #include <mm/frame.h>
  98. #include <config.h>
  99. #include <print.h>
  100. #include <arch.h>
  101. #include <panic.h>
  102. #include <debug.h>
  103. #include <bitops.h>
  104.  
  105. SPINLOCK_INITIALIZE(slab_cache_lock);
  106. static LIST_INITIALIZE(slab_cache_list);
  107.  
  108. /** Magazine cache */
  109. static slab_cache_t mag_cache;
  110. /** Cache for cache descriptors */
  111. static slab_cache_t slab_cache_cache;
  112.  
  113. /** Cache for external slab descriptors
  114.  * This time we want per-cpu cache, so do not make it static
  115.  * - using SLAB for internal SLAB structures will not deadlock,
  116.  *   as all slab structures are 'small' - control structures of
  117.  *   their caches do not require further allocation
  118.  */
  119. static slab_cache_t *slab_extern_cache;
  120. /** Caches for malloc */
  121. static slab_cache_t *malloc_caches[SLAB_MAX_MALLOC_W-SLAB_MIN_MALLOC_W+1];
  122. char *malloc_names[] =  {
  123.     "malloc-8","malloc-16","malloc-32","malloc-64","malloc-128",
  124.     "malloc-256","malloc-512","malloc-1K","malloc-2K",
  125.     "malloc-4K","malloc-8K","malloc-16K","malloc-32K",
  126.     "malloc-64K","malloc-128K"
  127. };
  128.  
  129. /** Slab descriptor */
  130. typedef struct {
  131.     slab_cache_t *cache; /**< Pointer to parent cache */
  132.     link_t link;       /* List of full/partial slabs */
  133.     void *start;       /**< Start address of first available item */
  134.     count_t available; /**< Count of available items in this slab */
  135.     index_t nextavail; /**< The index of next available item */
  136. }slab_t;
  137.  
  138. /**************************************/
  139. /* SLAB allocation functions          */
  140.  
  141. /**
  142.  * Allocate frames for slab space and initialize
  143.  *
  144.  */
  145. static slab_t * slab_space_alloc(slab_cache_t *cache, int flags)
  146. {
  147.     void *data;
  148.     slab_t *slab;
  149.     size_t fsize;
  150.     int i;
  151.     zone_t *zone = NULL;
  152.     int status;
  153.     frame_t *frame;
  154.  
  155.     data = (void *)frame_alloc(FRAME_KA | flags, cache->order, &status, &zone);
  156.     if (status != FRAME_OK) {
  157.         return NULL;
  158.     }
  159.     if (! (cache->flags & SLAB_CACHE_SLINSIDE)) {
  160.         slab = slab_alloc(slab_extern_cache, flags);
  161.         if (!slab) {
  162.             frame_free((__address)data);
  163.             return NULL;
  164.         }
  165.     } else {
  166.         fsize = (PAGE_SIZE << cache->order);
  167.         slab = data + fsize - sizeof(*slab);
  168.     }
  169.        
  170.     /* Fill in slab structures */
  171.     /* TODO: some better way of accessing the frame */
  172.     for (i=0; i < (1 << cache->order); i++) {
  173.         frame = ADDR2FRAME(zone, KA2PA((__address)(data+i*PAGE_SIZE)));
  174.         frame->parent = slab;
  175.     }
  176.  
  177.     slab->start = data;
  178.     slab->available = cache->objects;
  179.     slab->nextavail = 0;
  180.     slab->cache = cache;
  181.  
  182.     for (i=0; i<cache->objects;i++)
  183.         *((int *) (slab->start + i*cache->size)) = i+1;
  184.  
  185.     atomic_inc(&cache->allocated_slabs);
  186.     return slab;
  187. }
  188.  
  189. /**
  190.  * Deallocate space associated with SLAB
  191.  *
  192.  * @return number of freed frames
  193.  */
  194. static count_t slab_space_free(slab_cache_t *cache, slab_t *slab)
  195. {
  196.     frame_free((__address)slab->start);
  197.     if (! (cache->flags & SLAB_CACHE_SLINSIDE))
  198.         slab_free(slab_extern_cache, slab);
  199.  
  200.     atomic_dec(&cache->allocated_slabs);
  201.    
  202.     return 1 << cache->order;
  203. }
  204.  
  205. /** Map object to slab structure */
  206. static slab_t * obj2slab(void *obj)
  207. {
  208.     frame_t *frame;
  209.  
  210.     frame = frame_addr2frame((__address)obj);
  211.     return (slab_t *)frame->parent;
  212. }
  213.  
  214. /**************************************/
  215. /* SLAB functions */
  216.  
  217.  
  218. /**
  219.  * Return object to slab and call a destructor
  220.  *
  221.  * Assume the cache->lock is held;
  222.  *
  223.  * @param slab If the caller knows directly slab of the object, otherwise NULL
  224.  *
  225.  * @return Number of freed pages
  226.  */
  227. static count_t slab_obj_destroy(slab_cache_t *cache, void *obj,
  228.                 slab_t *slab)
  229. {
  230.     count_t frames = 0;
  231.  
  232.     if (!slab)
  233.         slab = obj2slab(obj);
  234.  
  235.     ASSERT(slab->cache == cache);
  236.  
  237.     *((int *)obj) = slab->nextavail;
  238.     slab->nextavail = (obj - slab->start)/cache->size;
  239.     slab->available++;
  240.  
  241.     /* Move it to correct list */
  242.     if (slab->available == 1) {
  243.         /* It was in full, move to partial */
  244.         list_remove(&slab->link);
  245.         list_prepend(&slab->link, &cache->partial_slabs);
  246.     }
  247.     if (slab->available == cache->objects) {
  248.         /* Free associated memory */
  249.         list_remove(&slab->link);
  250.         /* Avoid deadlock */
  251.         spinlock_unlock(&cache->lock);
  252.         frames = slab_space_free(cache, slab);
  253.         spinlock_lock(&cache->lock);
  254.     }
  255.  
  256.     return frames;
  257. }
  258.  
  259. /**
  260.  * Take new object from slab or create new if needed
  261.  *
  262.  * Assume cache->lock is held.
  263.  *
  264.  * @return Object address or null
  265.  */
  266. static void * slab_obj_create(slab_cache_t *cache, int flags)
  267. {
  268.     slab_t *slab;
  269.     void *obj;
  270.  
  271.     if (list_empty(&cache->partial_slabs)) {
  272.         /* Allow recursion and reclaiming
  273.          * - this should work, as the SLAB control structures
  274.          *   are small and do not need to allocte with anything
  275.          *   other ten frame_alloc when they are allocating,
  276.          *   that's why we should get recursion at most 1-level deep
  277.          */
  278.         spinlock_unlock(&cache->lock);
  279.         slab = slab_space_alloc(cache, flags);
  280.         spinlock_lock(&cache->lock);
  281.         if (!slab) {
  282.             return NULL;
  283.         }
  284.     } else {
  285.         slab = list_get_instance(cache->partial_slabs.next,
  286.                      slab_t,
  287.                      link);
  288.         list_remove(&slab->link);
  289.     }
  290.     obj = slab->start + slab->nextavail * cache->size;
  291.     slab->nextavail = *((int *)obj);
  292.     slab->available--;
  293.     if (! slab->available)
  294.         list_prepend(&slab->link, &cache->full_slabs);
  295.     else
  296.         list_prepend(&slab->link, &cache->partial_slabs);
  297.     return obj;
  298. }
  299.  
  300. /**************************************/
  301. /* CPU-Cache slab functions */
  302.  
  303. /**
  304.  * Free all objects in magazine and free memory associated with magazine
  305.  *
  306.  * Assume cache->lock is held
  307.  *
  308.  * @return Number of freed pages
  309.  */
  310. static count_t magazine_destroy(slab_cache_t *cache,
  311.                 slab_magazine_t *mag)
  312. {
  313.     int i;
  314.     count_t frames = 0;
  315.  
  316.     for (i=0;i < mag->busy; i++) {
  317.         frames += slab_obj_destroy(cache, mag->objs[i], NULL);
  318.         atomic_dec(&cache->cached_objs);
  319.     }
  320.    
  321.     slab_free(&mag_cache, mag);
  322.  
  323.     return frames;
  324. }
  325.  
  326. /**
  327.  * Find full magazine, set it as current and return it
  328.  *
  329.  * Assume cpu_magazine lock is held
  330.  */
  331. static slab_magazine_t * get_full_current_mag(slab_cache_t *cache)
  332. {
  333.     slab_magazine_t *cmag, *lastmag, *newmag;
  334.  
  335.     cmag = cache->mag_cache[CPU->id].current;
  336.     lastmag = cache->mag_cache[CPU->id].last;
  337.     if (cmag) { /* First try local CPU magazines */
  338.         if (cmag->busy)
  339.             return cmag;
  340.  
  341.         if (lastmag && lastmag->busy) {
  342.             cache->mag_cache[CPU->id].current = lastmag;
  343.             cache->mag_cache[CPU->id].last = cmag;
  344.             return lastmag;
  345.         }
  346.     }
  347.     /* Local magazines are empty, import one from magazine list */
  348.     spinlock_lock(&cache->lock);
  349.     if (list_empty(&cache->magazines)) {
  350.         spinlock_unlock(&cache->lock);
  351.         return NULL;
  352.     }
  353.     newmag = list_get_instance(cache->magazines.next,
  354.                    slab_magazine_t,
  355.                    link);
  356.     list_remove(&newmag->link);
  357.     spinlock_unlock(&cache->lock);
  358.  
  359.     if (lastmag)
  360.         slab_free(&mag_cache, lastmag);
  361.     cache->mag_cache[CPU->id].last = cmag;
  362.     cache->mag_cache[CPU->id].current = newmag;
  363.     return newmag;
  364. }
  365.  
  366. /**
  367.  * Try to find object in CPU-cache magazines
  368.  *
  369.  * @return Pointer to object or NULL if not available
  370.  */
  371. static void * magazine_obj_get(slab_cache_t *cache)
  372. {
  373.     slab_magazine_t *mag;
  374.     void *obj;
  375.  
  376.     if (!CPU)
  377.         return NULL;
  378.  
  379.     spinlock_lock(&cache->mag_cache[CPU->id].lock);
  380.  
  381.     mag = get_full_current_mag(cache);
  382.     if (!mag) {
  383.         spinlock_unlock(&cache->mag_cache[CPU->id].lock);
  384.         return NULL;
  385.     }
  386.     obj = mag->objs[--mag->busy];
  387.     spinlock_unlock(&cache->mag_cache[CPU->id].lock);
  388.     atomic_dec(&cache->cached_objs);
  389.    
  390.     return obj;
  391. }
  392.  
  393. /**
  394.  * Assure that the current magazine is empty, return pointer to it, or NULL if
  395.  * no empty magazine is available and cannot be allocated
  396.  *
  397.  * Assume mag_cache[CPU->id].lock is held
  398.  *
  399.  * We have 2 magazines bound to processor.
  400.  * First try the current.
  401.  *  If full, try the last.
  402.  *   If full, put to magazines list.
  403.  *   allocate new, exchange last & current
  404.  *
  405.  */
  406. static slab_magazine_t * make_empty_current_mag(slab_cache_t *cache)
  407. {
  408.     slab_magazine_t *cmag,*lastmag,*newmag;
  409.  
  410.     cmag = cache->mag_cache[CPU->id].current;
  411.     lastmag = cache->mag_cache[CPU->id].last;
  412.  
  413.     if (cmag) {
  414.         if (cmag->busy < cmag->size)
  415.             return cmag;
  416.         if (lastmag && lastmag->busy < lastmag->size) {
  417.             cache->mag_cache[CPU->id].last = cmag;
  418.             cache->mag_cache[CPU->id].current = lastmag;
  419.             return lastmag;
  420.         }
  421.     }
  422.     /* current | last are full | nonexistent, allocate new */
  423.     /* We do not want to sleep just because of caching */
  424.     /* Especially we do not want reclaiming to start, as
  425.      * this would deadlock */
  426.     newmag = slab_alloc(&mag_cache, FRAME_ATOMIC | FRAME_NO_RECLAIM);
  427.     if (!newmag)
  428.         return NULL;
  429.     newmag->size = SLAB_MAG_SIZE;
  430.     newmag->busy = 0;
  431.  
  432.     /* Flush last to magazine list */
  433.     if (lastmag) {
  434.         spinlock_lock(&cache->lock);
  435.         list_prepend(&lastmag->link, &cache->magazines);
  436.         spinlock_unlock(&cache->lock);
  437.     }
  438.     /* Move current as last, save new as current */
  439.     cache->mag_cache[CPU->id].last = cmag; 
  440.     cache->mag_cache[CPU->id].current = newmag;
  441.  
  442.     return newmag;
  443. }
  444.  
  445. /**
  446.  * Put object into CPU-cache magazine
  447.  *
  448.  * @return 0 - success, -1 - could not get memory
  449.  */
  450. static int magazine_obj_put(slab_cache_t *cache, void *obj)
  451. {
  452.     slab_magazine_t *mag;
  453.  
  454.     if (!CPU)
  455.         return -1;
  456.  
  457.     spinlock_lock(&cache->mag_cache[CPU->id].lock);
  458.  
  459.     mag = make_empty_current_mag(cache);
  460.     if (!mag) {
  461.         spinlock_unlock(&cache->mag_cache[CPU->id].lock);
  462.         return -1;
  463.     }
  464.    
  465.     mag->objs[mag->busy++] = obj;
  466.  
  467.     spinlock_unlock(&cache->mag_cache[CPU->id].lock);
  468.     atomic_inc(&cache->cached_objs);
  469.     return 0;
  470. }
  471.  
  472.  
  473. /**************************************/
  474. /* SLAB CACHE functions */
  475.  
  476. /** Return number of objects that fit in certain cache size */
  477. static int comp_objects(slab_cache_t *cache)
  478. {
  479.     if (cache->flags & SLAB_CACHE_SLINSIDE)
  480.         return ((PAGE_SIZE << cache->order) - sizeof(slab_t)) / cache->size;
  481.     else
  482.         return (PAGE_SIZE << cache->order) / cache->size;
  483. }
  484.  
  485. /** Return wasted space in slab */
  486. static int badness(slab_cache_t *cache)
  487. {
  488.     int objects;
  489.     int ssize;
  490.  
  491.     objects = comp_objects(cache);
  492.     ssize = PAGE_SIZE << cache->order;
  493.     if (cache->flags & SLAB_CACHE_SLINSIDE)
  494.         ssize -= sizeof(slab_t);
  495.     return ssize - objects*cache->size;
  496. }
  497.  
  498. /** Initialize allocated memory as a slab cache */
  499. static void
  500. _slab_cache_create(slab_cache_t *cache,
  501.            char *name,
  502.            size_t size,
  503.            size_t align,
  504.            int (*constructor)(void *obj, int kmflag),
  505.            void (*destructor)(void *obj),
  506.            int flags)
  507. {
  508.     int i;
  509.     int pages;
  510.  
  511.     memsetb((__address)cache, sizeof(*cache), 0);
  512.     cache->name = name;
  513.  
  514.     if (align < sizeof(__native))
  515.         align = sizeof(__native);
  516.     size = ALIGN_UP(size, align);
  517.        
  518.     cache->size = size;
  519.  
  520.     cache->constructor = constructor;
  521.     cache->destructor = destructor;
  522.     cache->flags = flags;
  523.  
  524.     list_initialize(&cache->full_slabs);
  525.     list_initialize(&cache->partial_slabs);
  526.     list_initialize(&cache->magazines);
  527.     spinlock_initialize(&cache->lock, "cachelock");
  528.     if (! (cache->flags & SLAB_CACHE_NOMAGAZINE)) {
  529.         for (i=0; i < config.cpu_count; i++) {
  530.             memsetb((__address)&cache->mag_cache[i],
  531.                 sizeof(cache->mag_cache[i]), 0);
  532.             spinlock_initialize(&cache->mag_cache[i].lock,
  533.                         "cpucachelock");
  534.         }
  535.     }
  536.  
  537.     /* Compute slab sizes, object counts in slabs etc. */
  538.     if (cache->size < SLAB_INSIDE_SIZE)
  539.         cache->flags |= SLAB_CACHE_SLINSIDE;
  540.  
  541.     /* Minimum slab order */
  542.     pages = ((cache->size-1) >> PAGE_WIDTH) + 1;
  543.     cache->order = fnzb(pages);
  544.  
  545.     while (badness(cache) > SLAB_MAX_BADNESS(cache)) {
  546.         cache->order += 1;
  547.     }
  548.     cache->objects = comp_objects(cache);
  549.     /* If info fits in, put it inside */
  550.     if (badness(cache) > sizeof(slab_t))
  551.         cache->flags |= SLAB_CACHE_SLINSIDE;
  552.  
  553.     spinlock_lock(&slab_cache_lock);
  554.  
  555.     list_append(&cache->link, &slab_cache_list);
  556.  
  557.     spinlock_unlock(&slab_cache_lock);
  558. }
  559.  
  560. /** Create slab cache  */
  561. slab_cache_t * slab_cache_create(char *name,
  562.                  size_t size,
  563.                  size_t align,
  564.                  int (*constructor)(void *obj, int kmflag),
  565.                  void (*destructor)(void *obj),
  566.                  int flags)
  567. {
  568.     slab_cache_t *cache;
  569.  
  570.     cache = slab_alloc(&slab_cache_cache, 0);
  571.     _slab_cache_create(cache, name, size, align, constructor, destructor,
  572.                flags);
  573.     return cache;
  574. }
  575.  
  576. /**
  577.  * Reclaim space occupied by objects that are already free
  578.  *
  579.  * @param flags If contains SLAB_RECLAIM_ALL, do aggressive freeing
  580.  * @return Number of freed pages
  581.  */
  582. static count_t _slab_reclaim(slab_cache_t *cache, int flags)
  583. {
  584.     int i;
  585.     slab_magazine_t *mag;
  586.     link_t *cur;
  587.     count_t frames = 0;
  588.    
  589.     if (cache->flags & SLAB_CACHE_NOMAGAZINE)
  590.         return 0; /* Nothing to do */
  591.    
  592.     /* First lock all cpu caches, then the complete cache lock */
  593.     if (flags & SLAB_RECLAIM_ALL) {
  594.         for (i=0; i < config.cpu_count; i++)
  595.             spinlock_lock(&cache->mag_cache[i].lock);
  596.     }
  597.     spinlock_lock(&cache->lock);
  598.    
  599.     if (flags & SLAB_RECLAIM_ALL) {
  600.         /* Aggressive memfree */
  601.         /* Destroy CPU magazines */
  602.         for (i=0; i<config.cpu_count; i++) {
  603.             mag = cache->mag_cache[i].current;
  604.             if (mag)
  605.                 frames += magazine_destroy(cache, mag);
  606.             cache->mag_cache[i].current = NULL;
  607.            
  608.             mag = cache->mag_cache[i].last;
  609.             if (mag)
  610.                 frames += magazine_destroy(cache, mag);
  611.             cache->mag_cache[i].last = NULL;
  612.         }
  613.     }
  614.     /* Destroy full magazines */
  615.     cur=cache->magazines.prev;
  616.  
  617.     while (cur != &cache->magazines) {
  618.         mag = list_get_instance(cur, slab_magazine_t, link);
  619.        
  620.         cur = cur->prev;
  621.         list_remove(&mag->link);
  622.         frames += magazine_destroy(cache,mag);
  623.         /* If we do not do full reclaim, break
  624.          * as soon as something is freed */
  625.         if (!(flags & SLAB_RECLAIM_ALL) && frames)
  626.             break;
  627.     }
  628.    
  629.     spinlock_unlock(&cache->lock);
  630.     /* We can release the cache locks now */
  631.     if (flags & SLAB_RECLAIM_ALL) {
  632.         for (i=0; i < config.cpu_count; i++)
  633.             spinlock_unlock(&cache->mag_cache[i].lock);
  634.     }
  635.    
  636.     return frames;
  637. }
  638.  
  639. /** Check that there are no slabs and remove cache from system  */
  640. void slab_cache_destroy(slab_cache_t *cache)
  641. {
  642.     /* Do not lock anything, we assume the software is correct and
  643.      * does not touch the cache when it decides to destroy it */
  644.    
  645.     /* Destroy all magazines */
  646.     _slab_reclaim(cache, SLAB_RECLAIM_ALL);
  647.  
  648.     /* All slabs must be empty */
  649.     if (!list_empty(&cache->full_slabs) \
  650.         || !list_empty(&cache->partial_slabs))
  651.         panic("Destroying cache that is not empty.");
  652.  
  653.     spinlock_lock(&slab_cache_lock);
  654.     list_remove(&cache->link);
  655.     spinlock_unlock(&slab_cache_lock);
  656.  
  657.     slab_free(&slab_cache_cache, cache);
  658. }
  659.  
  660. /** Allocate new object from cache - if no flags given, always returns
  661.     memory */
  662. void * slab_alloc(slab_cache_t *cache, int flags)
  663. {
  664.     ipl_t ipl;
  665.     void *result = NULL;
  666.    
  667.     /* Disable interrupts to avoid deadlocks with interrupt handlers */
  668.     ipl = interrupts_disable();
  669.  
  670.     if (!(cache->flags & SLAB_CACHE_NOMAGAZINE))
  671.         result = magazine_obj_get(cache);
  672.  
  673.     if (!result) {
  674.         spinlock_lock(&cache->lock);
  675.         result = slab_obj_create(cache, flags);
  676.         spinlock_unlock(&cache->lock);
  677.     }
  678.  
  679.     interrupts_restore(ipl);
  680.  
  681.     if (result)
  682.         atomic_inc(&cache->allocated_objs);
  683.  
  684.     return result;
  685. }
  686.  
  687. /** Return object to cache, use slab if known  */
  688. static void _slab_free(slab_cache_t *cache, void *obj, slab_t *slab)
  689. {
  690.     ipl_t ipl;
  691.  
  692.     ipl = interrupts_disable();
  693.  
  694.     if ((cache->flags & SLAB_CACHE_NOMAGAZINE) \
  695.         || magazine_obj_put(cache, obj)) {
  696.         spinlock_lock(&cache->lock);
  697.         slab_obj_destroy(cache, obj, slab);
  698.         spinlock_unlock(&cache->lock);
  699.     }
  700.     interrupts_restore(ipl);
  701.     atomic_dec(&cache->allocated_objs);
  702. }
  703.  
  704. /** Return slab object to cache */
  705. void slab_free(slab_cache_t *cache, void *obj)
  706. {
  707.     _slab_free(cache,obj,NULL);
  708. }
  709.  
  710. /* Go through all caches and reclaim what is possible */
  711. count_t slab_reclaim(int flags)
  712. {
  713.     slab_cache_t *cache;
  714.     link_t *cur;
  715.     count_t frames = 0;
  716.  
  717.     spinlock_lock(&slab_cache_lock);
  718.  
  719.     for (cur = slab_cache_list.next;cur!=&slab_cache_list; cur=cur->next) {
  720.         cache = list_get_instance(cur, slab_cache_t, link);
  721.         frames += _slab_reclaim(cache, flags);
  722.     }
  723.  
  724.     spinlock_unlock(&slab_cache_lock);
  725.  
  726.     return frames;
  727. }
  728.  
  729.  
  730. /* Print list of slabs */
  731. void slab_print_list(void)
  732. {
  733.     slab_cache_t *cache;
  734.     link_t *cur;
  735.  
  736.     spinlock_lock(&slab_cache_lock);
  737.     printf("SLAB name\tOsize\tPages\tObj/pg\tSlabs\tCached\tAllocobjs\tCtl\n");
  738.     for (cur = slab_cache_list.next;cur!=&slab_cache_list; cur=cur->next) {
  739.         cache = list_get_instance(cur, slab_cache_t, link);
  740.         printf("%s\t%d\t%d\t%d\t%d\t%d\t%d\t\t%s\n", cache->name, cache->size,
  741.                (1 << cache->order), cache->objects,
  742.                atomic_get(&cache->allocated_slabs),
  743.                atomic_get(&cache->cached_objs),
  744.                atomic_get(&cache->allocated_objs),
  745.                cache->flags & SLAB_CACHE_SLINSIDE ? "In" : "Out");
  746.     }
  747.     spinlock_unlock(&slab_cache_lock);
  748. }
  749.  
  750. void slab_cache_init(void)
  751. {
  752.     int i, size;
  753.  
  754.     /* Initialize magazine cache */
  755.     _slab_cache_create(&mag_cache,
  756.                "slab_magazine",
  757.                sizeof(slab_magazine_t)+SLAB_MAG_SIZE*sizeof(void*),
  758.                sizeof(__address),
  759.                NULL, NULL,
  760.                SLAB_CACHE_NOMAGAZINE | SLAB_CACHE_SLINSIDE);
  761.     /* Initialize slab_cache cache */
  762.     _slab_cache_create(&slab_cache_cache,
  763.                "slab_cache",
  764.                sizeof(slab_cache_cache) + config.cpu_count*sizeof(slab_cache_cache.mag_cache[0]),
  765.                sizeof(__address),
  766.                NULL, NULL,
  767.                SLAB_CACHE_NOMAGAZINE | SLAB_CACHE_SLINSIDE);
  768.     /* Initialize external slab cache */
  769.     slab_extern_cache = slab_cache_create("slab_extern",
  770.                           sizeof(slab_t),
  771.                           0, NULL, NULL,
  772.                           SLAB_CACHE_SLINSIDE);
  773.  
  774.     /* Initialize structures for malloc */
  775.     for (i=0, size=(1<<SLAB_MIN_MALLOC_W);
  776.          i < (SLAB_MAX_MALLOC_W-SLAB_MIN_MALLOC_W+1);
  777.          i++, size <<= 1) {
  778.         malloc_caches[i] = slab_cache_create(malloc_names[i],
  779.                              size, 0,
  780.                              NULL,NULL,0);
  781.     }
  782. }
  783.  
  784. /**************************************/
  785. /* kalloc/kfree functions             */
  786. void * kalloc(unsigned int size, int flags)
  787. {
  788.     int idx;
  789.    
  790.     ASSERT( size && size <= (1 << SLAB_MAX_MALLOC_W));
  791.    
  792.     if (size < (1 << SLAB_MIN_MALLOC_W))
  793.         size = (1 << SLAB_MIN_MALLOC_W);
  794.  
  795.     idx = fnzb(size-1) - SLAB_MIN_MALLOC_W + 1;
  796.  
  797.     return slab_alloc(malloc_caches[idx], flags);
  798. }
  799.  
  800.  
  801. void kfree(void *obj)
  802. {
  803.     slab_t *slab = obj2slab(obj);
  804.    
  805.     _slab_free(slab->cache, obj, slab);
  806. }
  807.