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

Mike Kravetz
2019-06-11T00:20:02Z

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>

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. Are there any other visible
effects?

--
Mike Kravetz