Re: [RFC PATCH 1/1] powerpc/ftrace: Exclude real mode code from

On Thu, 08 Mar 2018 00:07:07 +0530
"Naveen N. Rao" [off-list ref] wrote:

Yes, that's negligible.
Though, to be honest, I will have to introduce a 'mfmsr' for the older 
-pg variant. I still think that the improved reliability far outweighs 
the minor slowdown there.

In that case, can you introduce a read_mostly variable that can be
tested before calling the mfmsr. Why punish normal ftrace tracing if
kvm is not enabled or running?

Both should probably have an #ifdef CONFIG_KVM encapsulating the code.

-- Steve