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

[Mike Kravetz]

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@xxxxxxxxxxxxx>
> Fixes: 6bc9b56433b76 ("mm: fix race on soft-offlining")
> Cc: <stable@xxxxxxxxxxxxxxx> # v4.19+

Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>

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