On Tue, Aug 22, 2023 at 04:17:41PM -0700, Mike Kravetz wrote: > On 08/16/23 16:11, Matthew Wilcox (Oracle) wrote: > > Store the folio order in the low byte of the flags word in the first > > tail page. This frees up the word that was being used to store the > > order and dtor bytes previously. > > hugetlb manually creates and destroys compound pages. As such it makes > assumptions about struct page layout. This breaks hugetlb. The following > will allow fix the breakage. > > The hugetlb code is quite fragile when changes like this are made. I am > open to suggestions on how we can make this more robust. Perhaps start > with a simple set of APIs to create_folio from a set of contiguous pages > and destroy a folio? Thanks; those changes look good to me. I don't have any _immediate_ plans to make your life easier. When we get to a memdesc world, it'll all get much easier.