Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > So I suspect we should add that > > is_zero_pfn(page_to_pfn(page)) > > as a helper inline function rather than write it out even more times > (that "is this 'struct page' a zero page" pattern already exists in > /proc and a few other places. > > is_longterm_pinnable_page() already has it, so adding it as a helper > there in <linux/mm.h> is probably a good idea. I just added: static inline bool IS_ZERO_PAGE(const struct page *page) { return is_zero_pfn(page_to_pfn(page)); } static inline bool IS_ZERO_FOLIO(const struct folio *folio) { return is_zero_pfn(page_to_pfn((const struct page *)folio)); } to include/linux/pgtable.h. It doesn't seem I can add it to mm.h as an inline function. David