Re: [PATCH 0/15] x86/split_lock: Enable #AC exception for split locked accesses

[Dave Hansen]

On 05/15/2018 09:26 AM, Alan Cox wrote:
>> Could you describe the performance degradation?  Why is this not a
>> "doctor it hurts when I do that" situation?
> They already know it hurts - the question is why and where.

I thought there were also cross-VM and cross-process concerns where
somebody unprivileged can make the whole system slow down.  They might
even be malicious, so this isn't something that *just* hurts one app or
one VM.

I think that's what I wanted to see hit the changelog.