Re: [RFC 2/8] shmem: convert to use folio_test_hwpoison()

[Yang Shi]

On Fri, Apr 21, 2023 at 8:05 PM Luis Chamberlain <mcgrof@xxxxxxxxxx> wrote:
>
> On Fri, Apr 21, 2023 at 11:42:53PM +0100, Matthew Wilcox wrote:
> > On Fri, Apr 21, 2023 at 02:43:54PM -0700, Luis Chamberlain wrote:
> > > The PageHWPoison() call can be converted over to the respective folio call
> > > folio_test_hwpoison(). This introduces no functional changes.
> >
> > Um, no.  Nobody should use folio_test_hwpoison(), it's a nonsense.
> >
> > Individual pages are hwpoisoned.  You're only testing the head page
> > if you use folio_test_hwpoison().  There's folio_has_hwpoisoned() to
> > test if _any_ page in the folio is poisoned.  But blindly converting
> > PageHWPoison to folio_test_hwpoison() is wrong.
>
> Thanks! I don't see folio_has_hwpoisoned() though.

We do have PageHasHWPoisoned(), which indicates at least one subpage
is hwpoisoned in the huge page.

You may need to add a folio variant.

>
>   Luis
>