On Tue, 27 Mar 2018 11:57:07 +0800 Wei Yang <richard.weiyang@xxxxxxxxx> wrote:
> find_min_pfn_for_node() iterate on pfn range to find the minimum pfn for a
> node. The memblock_region in memblock_type are already ordered, which means
> the first hit in iteration is the minimum pfn.
>
> This patch returns the fist hit instead of iterating the whole regions.
>
> ...
>
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -6365,14 +6365,14 @@ unsigned long __init node_map_pfn_alignment(void)
> /* Find the lowest pfn for a node */
> static unsigned long __init find_min_pfn_for_node(int nid)
> {
> - unsigned long min_pfn = ULONG_MAX;
> - unsigned long start_pfn;
> + unsigned long min_pfn;
> int i;
>
> - for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
> - min_pfn = min(min_pfn, start_pfn);
> + for_each_mem_pfn_range(i, nid, &min_pfn, NULL, NULL) {
> + break;
> + }
That would be the weirdest-looking code snippet in mm/!
Can't we just use a single and simple call to __next_mem_pfn_range(),
or something like that?
>
> ...
>
