Re: [PATCH v2] x86/nmi: Add an emergency handler in nmi_desc & use it in nmi_shootdown_cpus()

[Thomas Gleixner]

On Wed, Dec 04 2024 at 23:01, Waiman Long wrote:
> On 12/4/24 2:28 PM, Waiman Long wrote:
>>> I'm not convinced that this should be used as a general mechanism. It's
>>> for emergency situations and that's where it stops. If the thing
>>> returns, it's a bug IMO.
>>
>> OK, I am fine with that. I will put a BUG_ON() after that in the next 
>> version.
>
> Actually, crash_nmi_callback() can return in the case of the crashing 
> CPUs, though all the other CPUs will not return once called. So I 
> believe the current form is correct. I will update the comment to 
> reflect that.

Why would you continue servicing the NMI on a CPU which just crashed?