free_area_init_nodes — Initialise all pg_data_t and zone data
|unsigned long * max_zone_pfn|
This will call
free_area_init_node for each active node in the system.
Using the page ranges provided by
memblock_set_node, the size of each
zone in each node and their holes is calculated. If the maximum PFN
between two adjacent zones match, it is assumed that the zone is empty.
For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
that arch_max_dma32_pfn has no pages. It is also assumed that a zone
starts where the previous one ended. For example, ZONE_DMA32 starts