> > Even than, does that preclude the format I suggested? I'm assuming > that pgd_t/pud_t/pmd_t are always a double word so the low order 4- > bits should be 0 (on 64-bit), so using the lsb as the flag between > hugetlb and normal pointer should still work. Might do, depends if David has enough bits ... David ? Cheers, Ben.