[LTP] Is MADV_HWPOISON supposed to work only on faulted-in pages?

[Andi Kleen]

> Well I disagree, the reason why the test fails is that MADV_HWPOISON on
> not-faulted private mappings fails silently, which is a bug, albeit
> minor one. If something is not implemented, it should report a failure,
> the usual error return would be EINVAL in this case.
> 
> It appears that it fails with EBUSY on first try on newer kernels, but
> still fails silently when we try for a second time.
> 
> Why can't we simply check if the page is faulted or not and return error
> in the latter case?

It's a debug interface. You're supposed to know what you're doing.

-Andi