On Thu, May 25, 2023 at 1:58 AM Mike Rapoport <rppt@xxxxxxxxxx> wrote: > > On Mon, May 01, 2023 at 12:27:57PM -0700, Vishal Moola (Oracle) wrote: > > s390 uses page->index to keep track of page tables for the guest address > > space. In an attempt to consolidate the usage of page fields in s390, > > replace _pt_pad_2 with _pt_s390_gaddr to replace page->index in gmap. > > > > This will help with the splitting of struct ptdesc from struct page, as > > well as allow s390 to use _pt_frag_refcount for fragmented page table > > tracking. > > > > Since page->_pt_s390_gaddr aliases with mapping, ensure its set to NULL > > before freeing the pages as well. > > Wouldn't it be easier to use _pt_pad_1 which is aliased with lru and that > does not seem to be used by page tables at all? I initially thought the same, but s390 page tables use lru.