Re: [RFC, PATCHv1 15/28] x86: detect 5-level paging support

From: hpa
Date: Thu Dec 15 2016 - 16:14:31 EST

On December 15, 2016 11:20:17 AM PST, Andi Kleen <ak@xxxxxxxxxxxxxxx> wrote:
>The code is not calling CPUID in any performance critical path, only
>at initialization. So any discussion about saving a few instructions
>is a complete waste of time.

NB: the chief offender is Loadlin, which is still used in some manufacturing flows that depends on a mix of legacy DOS and Linux applications; however, older versions of LILO also have this problem.
Sent from my Android device with K-9 Mail. Please excuse my brevity.