/* * uvm_swap_alloc: allocate space on swap * * => allocation is done "round robin" down the priority list, as we * allocate in a priority we "rotate" the circle queue. * => space can be freed with uvm_swap_free * => we return the page slot number in /dev/drum (0 == invalid slot) * => we lock uvm_swap_data_lock * => XXXMRG: "LESSOK" INTERFACE NEEDED TO EXTENT SYSTEM */