Currently, "the swap entry" in the page tables is used for a number of things outside of actual swap, like page migration, etc. We support the THP/PMD "swap entry" for page migration currently and the functions behind this are tied to page migration's config option (CONFIG_ARCH_ENABLE_THP_MIGRATION).
But, we also need them for THP swap optimization. So a new config option (CONFIG_HAVE_PMD_SWAP_ENTRY) is added. It is enabled when either CONFIG_ARCH_ENABLE_THP_MIGRATION or CONFIG_THP_SWAP is enabled. And PMD swap entry functions are tied to this new config option instead. Some functions enabled by CONFIG_ARCH_ENABLE_THP_MIGRATION are for page migration only, they are still enabled only for that. Signed-off-by: "Huang, Ying" <ying.hu...@intel.com> Cc: "Kirill A. Shutemov" <kirill.shute...@linux.intel.com> Cc: Andrea Arcangeli <aarca...@redhat.com> Cc: Michal Hocko <mho...@kernel.org> Cc: Johannes Weiner <han...@cmpxchg.org> Cc: Shaohua Li <s...@kernel.org> Cc: Hugh Dickins <hu...@google.com> Cc: Minchan Kim <minc...@kernel.org> Cc: Rik van Riel <r...@redhat.com> Cc: Dave Hansen <dave.han...@linux.intel.com> Cc: Naoya Horiguchi <n-horigu...@ah.jp.nec.com> Cc: Zi Yan <zi....@cs.rutgers.edu> Cc: Daniel Jordan <daniel.m.jor...@oracle.com> --- arch/x86/include/asm/pgtable.h | 2 +- include/asm-generic/pgtable.h | 2 +- include/linux/swapops.h | 44 ++++++++++++++++++---------------- mm/Kconfig | 8 +++++++ 4 files changed, 33 insertions(+), 23 deletions(-) diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 40616e805292..e830ab345551 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -1333,7 +1333,7 @@ static inline pte_t pte_swp_clear_soft_dirty(pte_t pte) return pte_clear_flags(pte, _PAGE_SWP_SOFT_DIRTY); } -#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION +#ifdef CONFIG_HAVE_PMD_SWAP_ENTRY static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd) { return pmd_set_flags(pmd, _PAGE_SWP_SOFT_DIRTY); diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index e0381a4ce7d4..2a619f378297 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -675,7 +675,7 @@ static inline void ptep_modify_prot_commit(struct mm_struct *mm, #endif #ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY -#ifndef CONFIG_ARCH_ENABLE_THP_MIGRATION +#ifndef CONFIG_HAVE_PMD_SWAP_ENTRY static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd) { return pmd; diff --git a/include/linux/swapops.h b/include/linux/swapops.h index 4d961668e5fc..905ddc65caa3 100644 --- a/include/linux/swapops.h +++ b/include/linux/swapops.h @@ -254,17 +254,7 @@ static inline int is_write_migration_entry(swp_entry_t entry) #endif -struct page_vma_mapped_walk; - -#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION -extern void set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, - struct page *page); - -extern void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, - struct page *new); - -extern void pmd_migration_entry_wait(struct mm_struct *mm, pmd_t *pmd); - +#ifdef CONFIG_HAVE_PMD_SWAP_ENTRY static inline swp_entry_t pmd_to_swp_entry(pmd_t pmd) { swp_entry_t arch_entry; @@ -282,6 +272,28 @@ static inline pmd_t swp_entry_to_pmd(swp_entry_t entry) arch_entry = __swp_entry(swp_type(entry), swp_offset(entry)); return __swp_entry_to_pmd(arch_entry); } +#else +static inline swp_entry_t pmd_to_swp_entry(pmd_t pmd) +{ + return swp_entry(0, 0); +} + +static inline pmd_t swp_entry_to_pmd(swp_entry_t entry) +{ + return __pmd(0); +} +#endif + +struct page_vma_mapped_walk; + +#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION +extern void set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, + struct page *page); + +extern void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, + struct page *new); + +extern void pmd_migration_entry_wait(struct mm_struct *mm, pmd_t *pmd); static inline int is_pmd_migration_entry(pmd_t pmd) { @@ -302,16 +314,6 @@ static inline void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, static inline void pmd_migration_entry_wait(struct mm_struct *m, pmd_t *p) { } -static inline swp_entry_t pmd_to_swp_entry(pmd_t pmd) -{ - return swp_entry(0, 0); -} - -static inline pmd_t swp_entry_to_pmd(swp_entry_t entry) -{ - return __pmd(0); -} - static inline int is_pmd_migration_entry(pmd_t pmd) { return 0; diff --git a/mm/Kconfig b/mm/Kconfig index 25c71eb8a7db..d7c5299c5b7d 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -422,6 +422,14 @@ config THP_SWAP For selection by architectures with reasonable THP sizes. +# +# "PMD swap entry" in the page table is used both for migration and +# actual swap. +# +config HAVE_PMD_SWAP_ENTRY + def_bool y + depends on THP_SWAP || ARCH_ENABLE_THP_MIGRATION + config TRANSPARENT_HUGE_PAGECACHE def_bool y depends on TRANSPARENT_HUGEPAGE -- 2.18.1