Re: [PATCH 4/4] mm/page_alloc: no need to ClearPageReserved on giving page to buddy system

Matthew Wilcox
2024-06-29T03:22:06Z

On Sat, Jun 29, 2024 at 01:33:22AM +0000, Wei Yang wrote:
> +++ b/mm/page_alloc.c
> @@ -1232,10 +1232,8 @@ void __meminit __free_pages_core(struct page *page, unsigned int order)
> prefetchw(p);
> for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
> prefetchw(p + 1);
> - __ClearPageReserved(p);
> set_page_count(p, 0);
> }
> - __ClearPageReserved(p);
> set_page_count(p, 0);

Is the prefetchw() still useful? Any remotely competent CPU should
be able to figure out this loop ...