On Fri, Jan 06, 2023 at 05:40:25PM +0000, SeongJae Park wrote: > The standard idiom for getting head page of a given folio is > '&folio->page'. It is efficient and safe even if the folio is NULL, > because the offset of page field in folio is zero. However, it makes > the code not that easy to understand at the first glance, especially the > NULL safety. Also, sometimes people forget the idiom and use > 'folio_page(folio, 0)' instead. To make it easier to read and remember, > add a new macro function called 'folio_headpage()' with the NULL case > explanation. Then, replace the 'folio_page(folio, 0)' calls with > 'folio_headpage(folio)'. No. Everywhere that uses &folio->page is a place that needs to be fixed. It shouldn't have a nice convenience macro. It should make you mildly uncomfortable.
