On Thu, Apr 01, 2021 at 01:52:01PM +0100, Matthew Wilcox wrote: > On Thu, Apr 01, 2021 at 09:28:03AM -0300, Jason Gunthorpe wrote: > > On Thu, Apr 01, 2021 at 12:26:56PM +0100, Matthew Wilcox wrote: > > > On Thu, Apr 01, 2021 at 08:05:37AM +0100, Christoph Hellwig wrote: > > > > On Wed, Mar 31, 2021 at 07:47:01PM +0100, Matthew Wilcox (Oracle) wrote: > > > > > - Mirror members of struct page (for pagecache / anon) into struct folio, > > > > > so (eg) you can use folio->mapping instead of folio->page.mapping > > > > > > > > Eww, why? > > > > > > So that eventually we can rename page->mapping to page->_mapping and > > > prevent the bugs from people doing page->mapping on a tail page. eg > > > https://lore.kernel.org/linux-mm/alpine.LSU.2.11.2103102214170.7159@eggly.anvils/ > > > > Is that gcc structure layout randomization stuff going to be a problem > > here? > > > > Add some > > static_assert(offsetof(struct folio,..) == offsetof(struct page,..)) > > > > tests to force it? > > You sound like the kind of person who hasn't read patch 1. Yes, I missed this hunk :) Jason
