Re: [PATCH v2 0/2] mm: soft-offline: fix race against page allocation

[Naoya Horiguchi]

On Wed, Aug 15, 2018 at 03:43:34PM -0700, Andrew Morton wrote:
> On Tue, 17 Jul 2018 14:32:30 +0900 Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> wrote:
> 
> > I've updated the patchset based on feedbacks:
> > 
> > - updated comments (from Andrew),
> > - moved calling set_hwpoison_free_buddy_page() from mm/migrate.c to mm/memory-failure.c,
> >   which is necessary to check the return code of set_hwpoison_free_buddy_page(),
> > - lkp bot reported a build error when only 1/2 is applied.
> > 
> >   >    mm/memory-failure.c: In function 'soft_offline_huge_page':
> >   > >> mm/memory-failure.c:1610:8: error: implicit declaration of function
> >   > 'set_hwpoison_free_buddy_page'; did you mean 'is_free_buddy_page'?
> >   > [-Werror=implicit-function-declaration]
> >   >        if (set_hwpoison_free_buddy_page(page))
> >   >            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >   >            is_free_buddy_page
> >   >    cc1: some warnings being treated as errors
> > 
> >   set_hwpoison_free_buddy_page() is defined in 2/2, so we can't use it
> >   in 1/2. Simply doing s/set_hwpoison_free_buddy_page/!TestSetPageHWPoison/
> >   will fix this.
> > 
> > v1: https://lkml.org/lkml/2018/7/12/968
> > 
> 
> Quite a bit of discussion on these two, but no actual acks or
> review-by's?

Really sorry for late response.
Xishi provided feedback on previous version, but no final ack/reviewed-by.
This fix should work on the reported issue, but rewriting soft-offlining
without PageHWPoison flag would be the better fix (no actual patch yet.)
I'm not sure this patch should go to mainline immediately.

Thanks,
Naoya Horiguchi