Re: [PATCH v2 1/2] mm: soft-offline: return -EBUSY if set_hwpoison_free_buddy_page() fails

Naoya Horiguchi
2019-06-12T07:25:35Z

On Tue, Jun 11, 2019 at 01:44:46PM +0530, Anshuman Khandual wrote:
>
>
> On 06/11/2019 06:27 AM, Naoya Horiguchi wrote:
> > On Mon, Jun 10, 2019 at 05:19:45PM -0700, Mike Kravetz wrote:
> >> On 6/10/19 1:18 AM, Naoya Horiguchi wrote:
> >>> The pass/fail of soft offline should be judged by checking whether the
> >>> raw error page was finally contained or not (i.e. the result of
> >>> set_hwpoison_free_buddy_page()), but current code do not work like that.
> >>> So this patch is suggesting to fix it.
> >>>
> >>> Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
> >>> Fixes: 6bc9b56433b76 ("mm: fix race on soft-offlining")
> >>> Cc: <stable@vger.kernel.org> # v4.19+
> >>
> >> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
> >
> > Thank you, Mike.
> >
> >>
> >> To follow-up on Andrew's comment/question about user visible effects. Without
> >> this fix, there are cases where madvise(MADV_SOFT_OFFLINE) may not offline the
> >> original page and will not return an error.
> >
> > Yes, that's right.
>
> Then should this be included in the commit message as well ?

Right, I'll clarify the point in the description.

Thanks,
- Naoya