Re: [PATCH v12 7/7] x86/crash: Add x86 crash hotplug support

[Borislav Petkov]

On Wed, Oct 12, 2022 at 03:19:19PM -0500, Eric DeVolder wrote:
> We run here QEMU with the ability for 1024 DIMM slots.

QEMU, haha.

What is the highest count of DIMM slots which are hotpluggable on a
real, *physical* system today? Are you saying you can have 1K DIMM slots
on a board?

I hardly doubt that.

> So, for example, 1TiB requires 1024 DIMMs of 1GiB each with 128MiB
> memblocks, that results in 8K possible memory regions. So just going
> to 4TiB reaches 32K memory regions.

Lemme see if I understand this correctly: when a system like that
crashes, you want to kdump *all* those 4TiB in a vmcore? How long would
that dump take to complete? A day?

IOW, how does a realistic use case of this look like - not a QEMU one?

Thx.

-- 
Regards/Gruss,
    Boris.

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