Re: [External] Re: [PATCH] mm: hugetlb: fix a race between memory-failure/soft_offline and gather_surplus_pages

Muchun Song
2021-04-21T08:58:45Z

On Wed, Apr 21, 2021 at 4:49 PM Oscar Salvador <osalvador@suse.de> wrote:
>
> On Wed, Apr 21, 2021 at 04:41:10PM +0800, Muchun Song wrote:
>
> > But softoffline does not set page hwpoison before
> > __get_hwpoison_page(). So the page still can be
> > allocated. Right?
>
> Yep, soft_offline() only marks the page as hwpoison once the page has been
> fully contended and no other use is possible.
> But yeah, hugetlb is a bit trickier in that regard.
>
> This needs fixing in there.

It is OK to fix it in softoffline/memory-failure.
I just want to expose the race. Thanks.

>
>
> --
> Oscar Salvador
> SUSE L3