Re: [PATCH v4 3/4] mm/sparse: Add a new parameter 'data_unit_size' for alloc_usemap_and_memmap

[Dave Hansen]

On 06/07/2018 11:27 PM, Baoquan He wrote:
> In alloc_usemap_and_memmap(), it will call
> sparse_early_usemaps_alloc_node() or sparse_early_mem_maps_alloc_node()
> to allocate usemap and memmap for each node and install them into
> usemap_map[] and map_map[]. Here we need pass in the number of present
> sections on this node so that we can move pointer of usemap_map[] and
> map_map[] to right position.
> 
> How do think about above words?

But you're now passing in the size of the data structure.  Why is that
needed all of a sudden?