On Sat, Jun 29, 2024 at 04:21:59AM +0100, Matthew Wilcox wrote: >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 ... Hi, Matthew Thanks for your question. But to be honest, I am not fully understand it. Per my understanding, prefetchw() is trying to load data to cache before we really accessing it. By doing so, we won't hit a cache miss when we really need it. This looks useful for me. And how remote competent CPU is involved in this process? -- Wei Yang Help you, Help me