On 19 September 2017 at 15:14, Florian Weimer fweimer@redhat.com wrote:
On 09/19/2017 08:08 PM, Stephen John Smoogen wrote:
Argh. This is an oversight on my part when bringing this as an option from the kernel team. I was not aware that the NX was dependent on PAE. The primary hardware that people were wanting all seemed to be below 4 GB so having PAE didn't seem to be worth the overhead. I am not sure if the OLPC desktops even have support for either NX or PAE. The people with P-III or no SSE2 definitely don't have PAE.
PAE is *way* older than NX/XD, but as you said, it does not matter for the old hardware because of RAM sizes and lack of NX/XD support.
There used to be an approximation to NX/XD based on segment register limits, but the art of writing userspace applications to make use of that may have been lost (and I don't know if the corresponding kernel code bits still exist and are being maintained).
I thought it got removed sometime in the 4 series as broken but no one reporting it broken for a long time.. but that could be something else.
Thanks, Florian