Function rt_slab_init

src/slab.c:324–383

* @brief This function will init slab memory management algorithm * * @param name is the name of the slab memory management object. * * @param begin_addr the beginning address of system page. * * @param size is the size of the memory. * * @return Return a pointer to the slab memory object. */

 * @return Return a pointer to the slab memory object.
 */
rt_slab_t rt_slab_init(const char *name, void *begin_addr, rt_size_t size)
{
    rt_uint32_t limsize, npages;
    rt_uintptr_t start_addr, begin_align, end_align;
    struct rt_slab *slab;

    slab = (struct rt_slab *)RT_ALIGN((rt_uintptr_t)begin_addr, RT_ALIGN_SIZE);
    start_addr = (rt_uintptr_t)slab + sizeof(*slab);
    /* align begin and end addr to page */
    begin_align = RT_ALIGN((rt_uintptr_t)start_addr, RT_MM_PAGE_SIZE);
    end_align   = RT_ALIGN_DOWN((rt_uintptr_t)begin_addr + size, RT_MM_PAGE_SIZE);
    if (begin_align >= end_align)
    {
        rt_kprintf("slab init errr. wrong address[0x%x - 0x%x]\n",
                   (rt_uintptr_t)begin_addr, (rt_uintptr_t)begin_addr + size);
        return RT_NULL;
    }

    limsize = end_align - begin_align;
    npages  = limsize / RT_MM_PAGE_SIZE;
    LOG_D("heap[0x%x - 0x%x], size 0x%x, 0x%x pages",
          begin_align, end_align, limsize, npages);

    rt_memset(slab, 0, sizeof(*slab));
    /* initialize slab memory object */
    rt_object_init(&(slab->parent.parent), RT_Object_Class_Memory, name);
    slab->parent.algorithm = "slab";
    slab->parent.address = begin_align;
    slab->parent.total = limsize;
    slab->parent.used = 0;
    slab->parent.max = 0;
    slab->heap_start = begin_align;
    slab->heap_end = end_align;

    /* init pages */
    rt_slab_page_init(slab, (void *)slab->heap_start, npages);

    /* calculate zone size */
    slab->zone_size = ZALLOC_MIN_ZONE_SIZE;
    while (slab->zone_size < ZALLOC_MAX_ZONE_SIZE && (slab->zone_size << 1) < (limsize / 1024))
        slab->zone_size <<= 1;

    slab->zone_limit = slab->zone_size / 4;
    if (slab->zone_limit > ZALLOC_ZONE_LIMIT)
        slab->zone_limit = ZALLOC_ZONE_LIMIT;

    slab->zone_page_cnt = slab->zone_size / RT_MM_PAGE_SIZE;

    LOG_D("zone size 0x%x, zone page count 0x%x",
          slab->zone_size, slab->zone_page_cnt);

    /* allocate slab->memusage array */
    limsize  = npages * sizeof(struct rt_slab_memusage);
    limsize  = RT_ALIGN(limsize, RT_MM_PAGE_SIZE);
    slab->memusage = rt_slab_page_alloc((rt_slab_t)(&slab->parent), limsize / RT_MM_PAGE_SIZE);

    LOG_D("slab->memusage 0x%x, size 0x%x",
          (rt_uintptr_t)slab->memusage, limsize);