Re: [PATCH v1 3/7] mm: rename and move page_is_poisoned()

[David Hildenbrand]

> > Long story short, this should be good enough for the cases we actually can
> > handle? What am I missing?
>
> I am not sure I follow. My point is that I fail to see any added value
> of the check as it doesn't prevent the race (it fundamentally cannot as
> the page can be poisoned at any time) but the failure path doesn't
> put_page which is incorrect even for hwpoison pages.

Oh, I think you are right. If we have a page and return NULL we would 
leak a reference.

Actually, we discussed in that thread handling this entirely 
differently, which resulted in a v7 [1]; however Andrew moved forward 
with this (outdated?) patch, maybe that was just a mistake?

Yes, I agree we should revert that patch for now.

Regarding the race comment: AFAIU e.g., [2], it's not really a problem 
with a race, but rather some corner case issue that can happen if we 
fail in memory_failure().


[1] https://lkml.kernel.org/r/20210406104123.451ee3c3@alex-virtual-machine
[2] 
https://lkml.kernel.org/r/20210331015258.GB22060@xxxxxxxxxxxxxxxxxxxxxxxxxxx

--
Thanks,

David / dhildenb