On Fri, Oct 03, 2014 at 07:08:00PM +0200, Andrea Arcangeli wrote: > There's one constraint enforced to allow this simplification: the > source pages passed to remap_anon_pages must be mapped only in one > vma, but this is not a limitation when used to handle userland page > faults with MADV_USERFAULT. The source addresses passed to > remap_anon_pages should be set as VM_DONTCOPY with MADV_DONTFORK to > avoid any risk of the mapcount of the pages increasing, if fork runs > in parallel in another thread, before or while remap_anon_pages runs. Have you considered triggering COW instead of adding limitation on pages' mapcount? The limitation looks artificial from interface POV. -- Kirill A. Shutemov -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
