* with swap entry format. On x86 bits 6 and 7 are *not* involved
* into swap entry computation, but bit 6 is used for nonlinear
* file mapping, so we borrow bit 7 for soft dirty tracking.
* with swap entry format. On x86 bits 6 and 7 are *not* involved
* into swap entry computation, but bit 6 is used for nonlinear
* file mapping, so we borrow bit 7 for soft dirty tracking.