Re: [PATCH v2 0/2] x86/mm: support memory-failure on 32-bits with SPARSEMEM

[Xie Yuanbin]

> This is a pretty generic description of MCEs.
>
> I think what we are missing is: who runs 32bit OSes on MCE-capable 
> hardware (or VMs?) and needs this to work.
>
> What's the use case?

Now, let me try to explain it. From what I understand, it mainly comes
from two aspects:
1. Although almost all new CPUs are 64-bit, there are still many existing
32-bit x86 devices in uses.
2. On some embedded devices, in order to save memory overhead, even with
64-bit CPU hardware, a 32-bit kernel may still be used. You might wonder
why embedded devices need SPARSEMEM. This is because the MEMORY_HOTPLUG
feature depends on SPARSEMEM, not necessarily SPARSEMEM itself.

All of the above devices, the memory-failure feature may be used to
provide reliable memory errors handling, and to minimize service
interruptions as much as possible.

> Cheers
>
> David

Thanks!

Xie Yuanbin