Re: [PATCH v3 2/4] mm/hwpoison: move definitions of num_poisoned_pages_* to memory-failure.c

[Miaohe Lin <linmiaohe@huawei.com>]

On 2022/9/21 17:13, Naoya Horiguchi wrote:
> From: Naoya Horiguchi <naoya.horiguchi@nec.com>
> 
> These interfaces will be used by drivers/base/core.c by later patch, so as a
> preparatory work move them to more common header file visible to the file.
> 
> Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
> ---
> ChangeLog v2 -> v3:
> - added declaration of num_poisoned_pages_inc() in #ifdef CONFIG_MEMORY_FAILURE
> ---
>  arch/parisc/kernel/pdt.c |  3 +--
>  include/linux/mm.h       |  5 +++++
>  include/linux/swapops.h  | 24 ++----------------------
>  mm/memory-failure.c      | 10 ++++++++++
>  4 files changed, 18 insertions(+), 24 deletions(-)
> 
> diff --git a/arch/parisc/kernel/pdt.c b/arch/parisc/kernel/pdt.c
> index e391b175f5ec..fdc880e2575a 100644
> --- a/arch/parisc/kernel/pdt.c
> +++ b/arch/parisc/kernel/pdt.c
> @@ -18,8 +18,7 @@
>  #include <linux/kthread.h>
>  #include <linux/initrd.h>
>  #include <linux/pgtable.h>
> -#include <linux/swap.h>

Is header file "linux/swap.h" already unneeded before the code change? It seems there's
no code change in that file.

> -#include <linux/swapops.h>
> +#include <linux/mm.h>
>  
>  #include <asm/pdc.h>
>  #include <asm/pdcpat.h>
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index c2277f5aba9e..80a2d800f272 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -3279,11 +3279,16 @@ extern atomic_long_t num_poisoned_pages __read_mostly;
>  extern int soft_offline_page(unsigned long pfn, int flags);
>  #ifdef CONFIG_MEMORY_FAILURE
>  extern int __get_huge_page_for_hwpoison(unsigned long pfn, int flags);
> +extern void num_poisoned_pages_inc(void);
>  #else
>  static inline int __get_huge_page_for_hwpoison(unsigned long pfn, int flags)
>  {
>  	return 0;
>  }
> +
> +static inline void num_poisoned_pages_inc(void)
> +{
> +}
>  #endif
>  
>  #ifndef arch_memory_failure
> diff --git a/include/linux/swapops.h b/include/linux/swapops.h
> index a91dd08e107b..3e58a812399a 100644
> --- a/include/linux/swapops.h
> +++ b/include/linux/swapops.h
> @@ -581,8 +581,6 @@ static inline int is_pmd_migration_entry(pmd_t pmd)
>  
>  #ifdef CONFIG_MEMORY_FAILURE
>  
> -extern atomic_long_t num_poisoned_pages __read_mostly;
> -
>  /*
>   * Support for hardware poisoned pages
>   */
> @@ -610,17 +608,7 @@ static inline struct page *hwpoison_entry_to_page(swp_entry_t entry)
>  	return p;
>  }
>  
> -static inline void num_poisoned_pages_inc(void)
> -{
> -	atomic_long_inc(&num_poisoned_pages);
> -}
> -
> -static inline void num_poisoned_pages_sub(long i)
> -{
> -	atomic_long_sub(i, &num_poisoned_pages);
> -}
> -
> -#else  /* CONFIG_MEMORY_FAILURE */
> +#else
>  
>  static inline swp_entry_t make_hwpoison_entry(struct page *page)
>  {
> @@ -636,15 +624,7 @@ static inline struct page *hwpoison_entry_to_page(swp_entry_t entry)
>  {
>  	return NULL;
>  }
> -
> -static inline void num_poisoned_pages_inc(void)
> -{
> -}
> -
> -static inline void num_poisoned_pages_sub(long i)
> -{
> -}
> -#endif  /* CONFIG_MEMORY_FAILURE */
> +#endif
>  
>  static inline int non_swap_entry(swp_entry_t entry)
>  {
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 5942e1c0407e..aa6ce685b863 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -74,6 +74,16 @@ atomic_long_t num_poisoned_pages __read_mostly = ATOMIC_LONG_INIT(0);
>  
>  static bool hw_memory_failure __read_mostly = false;
>  
> +static inline void num_poisoned_pages_inc(void)

This function is defined as "static inline" while it's "extern void num_poisoned_pages_inc(void)"
in the header file. Is this expected?

Thanks,
Miaohe Lin

> +{
> +	atomic_long_inc(&num_poisoned_pages);
> +}
> +
> +static inline void num_poisoned_pages_sub(long i)
> +{
> +	atomic_long_sub(i, &num_poisoned_pages);
> +}
> +
>  /*
>   * Return values:
>   *   1:   the page is dissolved (if needed) and taken off from buddy,
>