On 10/26/2017 11:09 PM, Alexander Ploumistos wrote:
On Thu, Oct 26, 2017 at 11:28 PM, Jeff Backus jeff.backus@gmail.com wrote:
Yes, we would need a +4GB RAM machine to test the PAE end of it, but any machine should be able to leverage the NX part of it.
The first NX-capable CPUs on the AMD side were Athlon 64 and P4 for Intel, right? Does that mean that we need to support 32-bit installations on 64-bit systems in general, or just the P4s?
I don't quite understand this discussion. Why does this even matter? You just test on the hardware you've got, and that's it. If it supports NX/XD, fine, but if it does not, that's okay as well. It's just another dimension in the test matrix, along with any other minor architecture revision which was introduced over the years.
It's not that the 32-bit PAE/NX code paths are something revolutionary new at this point. To me, it seems completely reasonable to assume that upstream isn't doing anything completely broken. I'm pretty sure that not disabling PAE/NX support will bring the Fedora x86 kernel more in line with what else is out there, too.
(FWIW, x86-64 support implies PAE support, but there are some obscure corner cases where NX/XD support is missing.)
Thanks, Florian