Re: [patch 28/30] x86/microcode: Handle "offline" CPUs correctly

[Thomas Gleixner]

On Thu, Aug 10 2023 at 16:02, Ashok Raj wrote:
> On Fri, Aug 11, 2023 at 12:29:57AM +0200, Peter Zijlstra wrote:
>> 
>> Yeah, not placing constraints on who is online at all. Also, if both
>> siblings are offline, then onlining will re-load ucode anyway, no?
>
> We need one thread in a core online,  because a MCE can happen and we don't
> want those running something stale.

Nonsense. This is a constraint at boot time. But afterwards it does not
matter at all. That's what Peter is talking about.