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

From: Michal Hocko
Date: Wed May 05 2021 - 09:45:54 EST


On Wed 05-05-21 15:39:08, David Hildenbrand wrote:
> > > 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 (outdated?)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.

OK, Let me send the revert to Andrew.

--
Michal Hocko
SUSE Labs