Re: [PATCH v1] mm: soft-offline: exit with failure for non anonymous thp

[Naoya Horiguchi]

On Fri, Jan 08, 2016 at 12:33:00PM -0800, Andrew Morton wrote:
> On Fri,  8 Jan 2016 16:24:02 +0900 Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> wrote:
>
> > Currently memory_failure() doesn't handle non anonymous thp case, because we
> > can hardly expect the error handling to be successful, and it can just hit
> > some corner case which results in BUG_ON or something severe like that.
> > This is also a case for soft offline code, so let's make it in the same way.
> >
> > ...
> >
> > --- v4.4-rc8/mm/memory-failure.c
> > +++ v4.4-rc8_patched/mm/memory-failure.c
> > @@ -1751,9 +1751,11 @@ int soft_offline_page(struct page *page, int flags)
> >         return -EBUSY;
> >     }
> >     if (!PageHuge(page) && PageTransHuge(hpage)) {
> > -       if (PageAnon(hpage) && unlikely(split_huge_page(hpage))) {
> > -           pr_info("soft offline: %#lx: failed to split THP\n",
> > -               pfn);
> > +       if (!PageAnon(hpage) || unlikely(split_huge_page(hpage))) {
> > +           if (!PageAnon(hpage))
> > +               pr_info("soft offline: %#lx: non anonymous thp\n", pfn);
> > +           else
> > +               pr_info("soft offline: %#lx: thp split failed\n", pfn);
> >             if (flags & MF_COUNT_INCREASED)
> >                 put_hwpoison_page(page);
> >             return -EBUSY;
>
> Kirill's
> http://ozlabs.org/~akpm/mmots/broken-out/thp-mm-split_huge_page-caller-need-to-lock-page.patch
> mucks with this code as well.  Could you please redo this patch against
> linux-next?

OK, I did it, which will come after this email.

Thanks,
Naoya Horiguchi