On 01/31/2014 04:25 PM, Kirill A. Shutemov wrote: >> > I think all we have to do is set a low bit in page->mapping > It's already in use to say page->mapping is anon_vma. ;) I weasel-worded that by not saying *THE* low bit. ;) We find *some* discriminator whether it be a page flag or an actual bit in page->mapping, or a magic value that doesn't collide with the existing PAGE_MAPPING_* flags. Poor 'struct page'. It's the doormat of data structures. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>