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

From: Peter Zijlstra
Date: Thu Jun 21 2018 - 18:13:48 EST


On Thu, Jun 21, 2018 at 03:00:03PM -0700, Fenghua Yu wrote:
> For example, on a consolidated real-time machine, some cores are running

> Another example, in a public cloud deployed in the field, a user process

In either case a single split-lock shouldn't be a real problem, if you
program the event with a count of 1 and have the NMI handler kill the
offending task, you should be good.

Not saying the #AC isn't nicer, just saying the PMU based thing can
still work.