On Mon, Apr 2, 2018 at 10:27 AM, Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> wrote: > > Aside: _PAGE_GLOBAL is ignored when CR4.PGE=1, so why do we > even go to the trouble of filtering it anywhere? I'm assuming this is a typo, and you mean "when CR4.PGE=0". The question you raise may be valid, but within the particular context of *this* patch it is not. In the context of this particular patch, the issue is that we use _PAGE_GLOBAL as _PAGE_BIT_PROTNONE when the present bit isn't set. Linus