Messages in this thread | | | Date | Thu, 05 Feb 2009 13:05:36 -0800 | From | Jeremy Fitzhardinge <> | Subject | Re: pud_bad vs pud_bad |
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Hugh Dickins wrote: >> Hardware doesn't allow it. It will explode (well, trap) if you set anything >> other than P in the top level. >> > > Oh, interesting, I'd never realized that. >
There are some later extensions to reuse some of the bits for things like tlb reload policy (I think; I'd have to check to be sure), so they're fairly non-pte-like.
>> By the by, what are the chances we'll be able to deprecate non-PAE 32-bit? >> > > I sincerely hope 0! I shed no tears at losing support for NUMAQ, > but why should we be forced to double all the 32-bit ptes? You want > us all to be using NX? Or you just want to cut your test/edit matrix - > that I can well understand! >
Yes, that's the gist of it. We could simplify things by having only one pte format and only have to parameterise with 3/4 level pagetables. We'd lose support for non-PAE cpus, including the first Pentium M (which is probably still in fairly wide use, unfortunately).
J
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