Re: [PATCH v1 02/11] mm: thp: introduce CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION

[Kirill A. Shutemov]

On Thu, Mar 03, 2016 at 04:41:49PM +0900, Naoya Horiguchi wrote:
> Introduces CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION to limit thp migration
> functionality to x86_64, which should be safer at the first step.

The name of the config option in description doesn't match the code.
> 
> Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
> ---
>  arch/x86/Kconfig        |  4 ++++
>  include/linux/huge_mm.h | 14 ++++++++++++++
>  mm/Kconfig              |  3 +++
>  3 files changed, 21 insertions(+)
> 
> diff --git v4.5-rc5-mmotm-2016-02-24-16-18/arch/x86/Kconfig v4.5-rc5-mmotm-2016-02-24-16-18_patched/arch/x86/Kconfig
> index 993aca4..7a563cf 100644
> --- v4.5-rc5-mmotm-2016-02-24-16-18/arch/x86/Kconfig
> +++ v4.5-rc5-mmotm-2016-02-24-16-18_patched/arch/x86/Kconfig
> @@ -2198,6 +2198,10 @@ config ARCH_ENABLE_HUGEPAGE_MIGRATION
>  	def_bool y
>  	depends on X86_64 && HUGETLB_PAGE && MIGRATION
>  
> +config ARCH_ENABLE_THP_MIGRATION
> +	def_bool y
> +	depends on X86_64 && TRANSPARENT_HUGEPAGE && MIGRATION
> +
>  menu "Power management and ACPI options"
>  
>  config ARCH_HIBERNATION_HEADER
> diff --git v4.5-rc5-mmotm-2016-02-24-16-18/include/linux/huge_mm.h v4.5-rc5-mmotm-2016-02-24-16-18_patched/include/linux/huge_mm.h
> index 459fd25..09b215d 100644
> --- v4.5-rc5-mmotm-2016-02-24-16-18/include/linux/huge_mm.h
> +++ v4.5-rc5-mmotm-2016-02-24-16-18_patched/include/linux/huge_mm.h
> @@ -156,6 +156,15 @@ static inline bool is_huge_zero_pmd(pmd_t pmd)
>  
>  struct page *get_huge_zero_page(void);
>  
> +static inline bool thp_migration_supported(void)
> +{
> +#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
> +	return true;
> +#else
> +	return false;
> +#endif

	return IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION);

	?
> +}
> +
>  #else /* CONFIG_TRANSPARENT_HUGEPAGE */
>  #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
>  #define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
> @@ -213,6 +222,11 @@ static inline struct page *follow_devmap_pmd(struct vm_area_struct *vma,
>  {
>  	return NULL;
>  }
> +
> +static inline bool thp_migration_supported(void)
> +{
> +	return false;
> +}
>  #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
>  
>  #endif /* _LINUX_HUGE_MM_H */
> diff --git v4.5-rc5-mmotm-2016-02-24-16-18/mm/Kconfig v4.5-rc5-mmotm-2016-02-24-16-18_patched/mm/Kconfig
> index f2c1a07..64e7ab6 100644
> --- v4.5-rc5-mmotm-2016-02-24-16-18/mm/Kconfig
> +++ v4.5-rc5-mmotm-2016-02-24-16-18_patched/mm/Kconfig
> @@ -265,6 +265,9 @@ config MIGRATION
>  config ARCH_ENABLE_HUGEPAGE_MIGRATION
>  	bool
>  
> +config ARCH_ENABLE_THP_MIGRATION
> +	bool
> +
>  config PHYS_ADDR_T_64BIT
>  	def_bool 64BIT || ARCH_PHYS_ADDR_T_64BIT
>  
> -- 
> 2.7.0
> 
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-- 
 Kirill A. Shutemov