On Tue 18-04-17 19:56:41, Sergey Senozhatsky wrote: > On (04/18/17 09:33), Michal Hocko wrote: > [..] > > > Another approach is the API does normal thing for non-aligned prefix and > > > tail space and fast thing for aligned space. > > > Otherwise, it would be happy if the API has WARN_ON non-page SIZE aligned > > > address. > > > > copy_page is a performance sensitive function and I believe that we do > > those tricks exactly for this purpose. > > a wild thought, > > use > #define copy_page(to,from) memcpy((to), (from), PAGE_SIZE) > > when DEBUG_SLAB is set? so arch copy_page() (if provided by arch) > won't be affected otherwise.
Wouldn't this just paper over bugs? SLAB is not guaranteed to provide page size aligned object AFAIR. -- Michal Hocko SUSE Labs
