内存管理之bootmem管理之标记内存

最新推荐文章于 2023-05-13 14:36:00 发布

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本文介绍了内核启动过程中用于标记内存区域的两个关键函数：mark_bootmem_node和mark_bootmem。这些函数负责在指定节点上预留或释放内存，并在遍历所有节点的过程中协调内存资源的分配。

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主要有mark_bootmem_node和mark_bootmem两个函数

static int __init mark_bootmem_node(bootmem_data_t *bdata,
				unsigned long start, unsigned long end,
				int reserve, int flags)
{
	unsigned long sidx, eidx;


	bdebug("nid=%td start=%lx end=%lx reserve=%d flags=%x\n",
		bdata - bootmem_node_data, start, end, reserve, flags);


	BUG_ON(start < bdata->node_min_pfn);
	BUG_ON(end > bdata->node_low_pfn);


	sidx = start - bdata->node_min_pfn;
	eidx = end - bdata->node_min_pfn;


	if (reserve)
		return __reserve(bdata, sidx, eidx, flags);
	else
		__free(bdata, sidx, eidx);
	return 0;
}

static int __init mark_bootmem(unsigned long start, unsigned long end,
				int reserve, int flags)
{
	unsigned long pos;
	bootmem_data_t *bdata;


	pos = start;
	list_for_each_entry(bdata, &bdata_list, list) {
		int err;
		unsigned long max;


		if (pos < bdata->node_min_pfn ||
		    pos >= bdata->node_low_pfn) {
			BUG_ON(pos != start);
			continue;
		}


		max = min(bdata->node_low_pfn, end);


		err = mark_bootmem_node(bdata, pos, max, reserve, flags);
		if (reserve && err) {
			mark_bootmem(start, pos, 0, 0);
			return err;
		}


		if (max == end)
			return 0;
		pos = bdata->node_low_pfn;
	}
	BUG();
}