Function _do_pages_alloc

components/mm/mm_page.c:825–873

volatile static rt_ubase_t _last_alloc;

rt_inline void *_do_pages_alloc(rt_uint32_t size_bits, size_t flags, int affid)
{
    void *alloc_buf = RT_NULL;
    struct rt_page *p;
    rt_base_t level;
    pgls_agr_t *page_list = _flag_to_page_list(flags);

    level = rt_spin_lock_irqsave(&_pgmgr_lock);
    p = pages_alloc_handler(page_list, size_bits, affid);
    if (p)
    {
        _freed_nr -= 1 << size_bits;
    }
    rt_spin_unlock_irqrestore(&_pgmgr_lock, level);

    if (!p && page_list != page_list_low)
    {
        /* fall back */
        page_list = page_list_low;

        level = rt_spin_lock_irqsave(&_pgmgr_lock);
        p = pages_alloc_handler(page_list, size_bits, affid);
        if (p)
        {
            _freed_nr -= 1 << size_bits;
            _freed_nr_hi -= 1 << size_bits;
        }
        rt_spin_unlock_irqrestore(&_pgmgr_lock, level);
    }

    if (p)
    {
        alloc_buf = page_to_addr(p);
        _last_alloc = (rt_ubase_t)alloc_buf;

        #ifdef RT_DEBUGGING_PAGE_LEAK
            level = rt_spin_lock_irqsave(&_spinlock);
            TRACE_ALLOC(p, size_bits);
            rt_spin_unlock_irqrestore(&_spinlock, level);
        #endif

#ifdef RT_DEBUGGING_PAGE_POISON
        _unpoisoned_pages(alloc_buf, size_bits);
#endif /* RT_DEBUGGING_PAGE_POISON */

    }

    return alloc_buf;
}

rt_inline int _get_balanced_id(rt_uint32_t size_bits)
{