Re: [PATCH v10 6/6] selftests/mm: add hwpoison-panic destructive test

[Breno Leitao]

On Wed, Jul 29, 2026 at 09:25:16AM +0200, David Hildenbrand (Arm) wrote:
> On 7/29/26 00:07, Breno Leitao wrote:
> > I have a draft of the selftest in C already and I will give it more bake
> > time, and I will submit it until EOW.
>
> IMHO there is no need to rush this test here, we could merge it after the main work.
>
> We neglected our selftests quite a bit in the past, and that is biting us now.
>
> That's why I push back hard now (sorry) against stuff that is different than the
> rest and not easy to maintain.
>
> I know, hwpoison-panic is a destructive test, but I really don't think we should
> just merge mostly unreviewed bash tests that will just bitrot.
>
> Which makes me wonder now: should this actually be a selftest? It's nothing one
> would just want to run in a CI. It will crash your machine.
>
> Maybe this should just be a tool in tools/mm? I really think so. So having a
> nice C-level hwpoison-panic.c in tools/mm might be the way to go.

Agreed. In v6 [0] I actually removed the selftest entirely, since the value
wasn't clear and it seemed like an ugly duckling.

It seems tools/mm would be a good fit, and make a better home for this
type of "test".

Given more changes coming in memory failure (at least from my side
[1][2]), I think it would be a good idea to create a subdirectory
(tools/mm/memory-failure) and keep these semi-destructive tools in there. Is
this the right direction?

> So let's rather make this test well maintainable and have it properly reviewed
> than rushing something suboptimal.

Sounds good. I'll move this to tools/mm and resubmit. Given Andrew has
removed the selftest from mm-unstable while keeping the rest of the
series (which is fully reviewed and frictionless), so I'll focus on the
test tool now and send it separately.

Thanks for the discussion,
--breno

Link: https://lore.kernel.org/all/20260511-ecc_panic-v6-0-183012ba7d4b@xxxxxxxxxx/ [0]
Link: https://lore.kernel.org/all/20260728-kexec_posioned-v1-1-160c81d180fe@xxxxxxxxxx/ [1]
Link: https://lore.kernel.org/all/20260717-hwpoison-kho-v1-0-9c5eda551998@xxxxxxxxxx/ [2]