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

Naoya Horiguchi
2022-09-27T12:54:02Z

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@huawei.com>

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@walle.cc/
, 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@ik1-406-35019.vs.sakura.ne.jp/

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.)

Thanks,
Naoya Horiguchi

> ---
> 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
>
>
>