内存管理之bootmem管理之释放内存

主要还是两个函数free_bootmem_node和free_bootmem

这里主要是标记相应比特位为0，空闲。

/**
 * free_bootmem_node - mark a page range as usable
 * @pgdat: node the range resides on
 * @physaddr: starting address of the range
 * @size: size of the range in bytes
 *
 * Partial pages will be considered reserved and left as they are.
 *
 * The range must reside completely on the specified node.
 */
void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
     unsigned long size)
{
unsigned long start, end;

kmemleak_free_part_phys(physaddr, size);

start = PFN_UP(physaddr);
end = PFN_DOWN(physaddr + size);
mark_bootmem_node(pgdat->bdata, start, end, 0, 0);
}

/** * free_bootmem - mark a page range as usable * @addr: starting physical address of the range * @size: size of the range in bytes * * Partial pages will be considered reserved and left as they are. * * The range must be contiguous but may span node boundaries. */void __init free_bootmem(unsigned long physaddr, unsigned long size){unsigned long start, end;kmemleak_free_part_phys(physaddr, size);start = PFN_UP(physaddr);end = PFN_DOWN(physaddr + size);mark_bootmem(start, end, 0, 0);}