Re: [PATCH] mm/hwpoison: fix build error without CONFIG_MEMORY_FAILURE

[Hui Tang]

On 2022/9/27 20:53, Naoya Horiguchi wrote:
> On Tue, Sep 27, 2022 at 06:29:46PM +0800, Hui Tang wrote:
> > Building without CONFIG_MEMORY_FAILURE will fail:
> >
> > mm/memory-failure.o: In function `action_result':
> > memory-failure.c: undefined reference to `memblk_nr_poison_inc'
> > mm/memory-failure.o: In function `page_handle_poison':
> > memory-failure.c: undefined reference to `memblk_nr_poison_inc'
> > mm/memory-failure.o: In function `__get_huge_page_for_hwpoison':
> > memory-failure.c: undefined reference to `memblk_nr_poison_inc'
> > mm/memory-failure.o: In function `unpoison_memory':
> > memory-failure.c: undefined reference to `memblk_nr_poison_sub'
> > mm/memory-failure.o: In function `num_poisoned_pages_inc':
> > memory-failure.c: undefined reference to `memblk_nr_poison_inc'
> >
> > Add CONFIG_MEMORY_FAILURE wrapper for invoking memblk_nr_poison_{inc|sub}.
> >
> > Fixes: 69b496f03bb4 ("mm/hwpoison: introduce per-memory_block hwpoison counter")
> > Signed-off-by: Hui Tang <tanghui20@xxxxxxxxxx>
>
> Thank you for the patch.  I have a question.
> If you disables CONFIG_MEMORY_FAILURE, mm/memory-failure.c should
> not be compiled, so I wonder why you saw the compile error.
> Could you share your .config file?
>
> Acutally I saw the similar report a few days ago
> https://lore.kernel.org/lkml/20220923095013.1151252-1-michael@xxxxxxxx/
> , where the build error happened in aarch64,  so I likely missed some arch
> dependency.  I responded to the report by updating the patch by applying
> "#if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_MEMORY_HOTPLUG)"
> to the definition of memblk_nr_poison_{inc,sub}.
> https://lore.kernel.org/lkml/20220923141204.GA1484969@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx/
>
> I did not confirm that this fix is really right, because I can't reproduced
> the build error in my environment.  So could you check that v5 patch fixes
> the build error you're seeing?  (The current version in mm-unstable is v4,
> so that should be replaced with v5.)

  Yes, when appling the latest patch, this build error is gone, thanks.

> > ---
> >  mm/memory-failure.c | 4 ++++
> >  1 file changed, 4 insertions(+)
> >
> > diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> > index 03479895086d..5bb9d2d20234 100644
> > --- a/mm/memory-failure.c
> > +++ b/mm/memory-failure.c
> > @@ -77,14 +77,18 @@ static bool hw_memory_failure __read_mostly = false;
> >  void num_poisoned_pages_inc(unsigned long pfn)
> >  {
> >  	atomic_long_inc(&num_poisoned_pages);
> > +#ifdef CONFIG_MEMORY_FAILURE
> >  	memblk_nr_poison_inc(pfn);
> > +#endif
> >  }
> >
> >  static inline void num_poisoned_pages_sub(unsigned long pfn, long i)
> >  {
> >  	atomic_long_sub(i, &num_poisoned_pages);
> > +#ifdef CONFIG_MEMORY_FAILURE
> >  	if (pfn != -1UL)
> >  		memblk_nr_poison_sub(pfn, i);
> > +#endif
> >  }
> >
> >  /*
> > --
> > 2.17.1
> .