Re: [RFC PATCH 00/16] x86/split_lock: Enable #AC exception for split locked accesses

From: Peter Zijlstra
Date: Thu Jun 21 2018 - 18:08:54 EST


On Thu, Jun 21, 2018 at 03:00:03PM -0700, Fenghua Yu wrote:
> The control knob for kernel is to choose re-executing the faulting
> instruction (default) or kernel panic. Kernel panic may be useful in hard
> real time which has less tolerant to bad performance.

The kernel should never trigger this, ever. Any #AC is a plain bug and
should be fixed. So unconditional WARN+disable is suffient.