Re: [PATCH v13 7/7] x86/crash: add x86 crash hotplug support

Eric DeVolder
2022-11-02T16:54:53Z

On 11/2/22 11:19, Borislav Petkov wrote:
> On Wed, Nov 02, 2022 at 09:55:06AM -0500, Eric DeVolder wrote:
>>> "But on a plain simple laptop or workstation which has CPU hotplug,
>>> would it make sense for the crash ranges to get updated too when CPUs
>>> are offlined?
>>
>> Yes, it does.
>
> Why?
>

Technically the answer is no; cpu hotplug events are independent of memory hotplug events, but both
are written into the elfcorehdr, so in reality yes... The elfcorehdr contains a single list of Phdrs
describing CPUs and crash memory ranges; the entire list is re-written on a hotplug change.

Eric