Re: [PATCH v2 5/8] x86/msr: write_rdtscp_aux() to use wrmsr_safe()

From: Andy Lutomirski
Date: Wed Jun 06 2018 - 13:11:28 EST


On Wed, Jun 6, 2018 at 9:23 AM Chang S. Bae <chang.seok.bae@xxxxxxxxx> wrote:
>
> Using wrmsr_safe() can make code a bit simpler by removing
> some condition check

NAK.

If we really want to stop checking the cpu feature and unconditionally
write the MSR, then there should be a single patch that does it. If
we don't, then we should not make this change, since it will make the
very useful warning if we screwed it up go away.

I think we should continue checking the cpu feature, personally. I
also thing that, if we make the change, it should not be part of the
FSGSBASE series.