diff --git a/arch/arm/mm/hugetlbpage.c b/arch/arm/mm/hugetlbpage.c index 66781bf34077cb540a67f845eeeb919c2decfc4e..54ee6163c1814453298272fdb182341e3a5ffcdf 100644 --- a/arch/arm/mm/hugetlbpage.c +++ b/arch/arm/mm/hugetlbpage.c @@ -56,3 +56,8 @@ int pmd_huge(pmd_t pmd) { return pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT); } + +int pmd_huge_support(void) +{ + return 1; +} diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c index 2fc8258bab2df614ab51a0bf1ffb4a36a236ba41..5e9aec358306f0c13bdd0bb70758dde88be9e961 100644 --- a/arch/arm64/mm/hugetlbpage.c +++ b/arch/arm64/mm/hugetlbpage.c @@ -54,6 +54,11 @@ int pud_huge(pud_t pud) return !(pud_val(pud) & PUD_TABLE_BIT); } +int pmd_huge_support(void) +{ + return 1; +} + static __init int setup_hugepagesz(char *opt) { unsigned long ps = memparse(opt, &opt); diff --git a/arch/ia64/mm/hugetlbpage.c b/arch/ia64/mm/hugetlbpage.c index 76069c18ee42c186edf37c680ee78249d553b4fc..68232db98baa74856752a86fc63cc12678e76787 100644 --- a/arch/ia64/mm/hugetlbpage.c +++ b/arch/ia64/mm/hugetlbpage.c @@ -114,6 +114,11 @@ int pud_huge(pud_t pud) return 0; } +int pmd_huge_support(void) +{ + return 0; +} + struct page * follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int write) { diff --git a/arch/metag/mm/hugetlbpage.c b/arch/metag/mm/hugetlbpage.c index 3c52fa6d0f8e24030294fecacc26498f5de9ffe5..042431509b5664bca9bc6c930b296c77a064079a 100644 --- a/arch/metag/mm/hugetlbpage.c +++ b/arch/metag/mm/hugetlbpage.c @@ -110,6 +110,11 @@ int pud_huge(pud_t pud) return 0; } +int pmd_huge_support(void) +{ + return 1; +} + struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int write) { diff --git a/arch/mips/mm/hugetlbpage.c b/arch/mips/mm/hugetlbpage.c index a7fee0dfb7a9daaeb67616804f00cac7365d778f..01fda4419ed09de2e5adbfcd0b318023f3cc7664 100644 --- a/arch/mips/mm/hugetlbpage.c +++ b/arch/mips/mm/hugetlbpage.c @@ -85,6 +85,11 @@ int pud_huge(pud_t pud) return (pud_val(pud) & _PAGE_HUGE) != 0; } +int pmd_huge_support(void) +{ + return 1; +} + struct page * follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int write) diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c index 834ca8eb38f202e01c5151fdb56b13197ed6acc8..d67db4bd672dd4223065c9b5470ee368a9456d1d 100644 --- a/arch/powerpc/mm/hugetlbpage.c +++ b/arch/powerpc/mm/hugetlbpage.c @@ -86,6 +86,11 @@ int pgd_huge(pgd_t pgd) */ return ((pgd_val(pgd) & 0x3) != 0x0); } + +int pmd_huge_support(void) +{ + return 1; +} #else int pmd_huge(pmd_t pmd) { @@ -101,6 +106,11 @@ int pgd_huge(pgd_t pgd) { return 0; } + +int pmd_huge_support(void) +{ + return 0; +} #endif pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c index 248445f92604efff09a5188352c3e6fba1248bb0..d261c62e40a68f8c885d6019e6a0ef27d9497c4c 100644 --- a/arch/s390/mm/hugetlbpage.c +++ b/arch/s390/mm/hugetlbpage.c @@ -223,6 +223,11 @@ int pud_huge(pud_t pud) return 0; } +int pmd_huge_support(void) +{ + return 1; +} + struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmdp, int write) { diff --git a/arch/sh/mm/hugetlbpage.c b/arch/sh/mm/hugetlbpage.c index d7762349ea4869be1b40898a5ae7e6ff8e79c6aa..0d676a41081e873582a68cf3c1d179ab51dd529d 100644 --- a/arch/sh/mm/hugetlbpage.c +++ b/arch/sh/mm/hugetlbpage.c @@ -83,6 +83,11 @@ int pud_huge(pud_t pud) return 0; } +int pmd_huge_support(void) +{ + return 0; +} + struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int write) { diff --git a/arch/sparc/mm/hugetlbpage.c b/arch/sparc/mm/hugetlbpage.c index d2b59441ebddfb84080da0fcadff6921e71342f6..96399646570a780e1b38a6324994c5f71470bb0b 100644 --- a/arch/sparc/mm/hugetlbpage.c +++ b/arch/sparc/mm/hugetlbpage.c @@ -234,6 +234,11 @@ int pud_huge(pud_t pud) return 0; } +int pmd_huge_support(void) +{ + return 0; +} + struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int write) { diff --git a/arch/tile/mm/hugetlbpage.c b/arch/tile/mm/hugetlbpage.c index e514899e1100319dc83fe69530f1aad67b17ceea..0cb3bbaa580c5dbc5ed00417ffd4b6e002c03813 100644 --- a/arch/tile/mm/hugetlbpage.c +++ b/arch/tile/mm/hugetlbpage.c @@ -166,6 +166,11 @@ int pud_huge(pud_t pud) return !!(pud_val(pud) & _PAGE_HUGE_PAGE); } +int pmd_huge_support(void) +{ + return 1; +} + struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int write) { diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c index 7e73e8c690966dccbd8a7ef9f3d5397a367828f1..9d980d88b7477a82f757e75d0efda0c867c76d43 100644 --- a/arch/x86/mm/hugetlbpage.c +++ b/arch/x86/mm/hugetlbpage.c @@ -59,6 +59,10 @@ follow_huge_pmd(struct mm_struct *mm, unsigned long address, return NULL; } +int pmd_huge_support(void) +{ + return 0; +} #else struct page * @@ -77,6 +81,10 @@ int pud_huge(pud_t pud) return !!(pud_val(pud) & _PAGE_PSE); } +int pmd_huge_support(void) +{ + return 1; +} #endif /* x86_64 also uses this file */ diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 2e02c4ed1035713e7491ce837a6a62ebcf02fb18..0393270466c3fd8a59d24781cf54ab5ffd0c5a57 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -381,6 +381,16 @@ static inline pgoff_t basepage_index(struct page *page) extern void dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn); +int pmd_huge_support(void); +/* + * Currently hugepage migration is enabled only for pmd-based hugepage. + * This function will be updated when hugepage migration is more widely + * supported. + */ +static inline int hugepage_migration_support(struct hstate *h) +{ + return pmd_huge_support() && (huge_page_shift(h) == PMD_SHIFT); +} #else /* CONFIG_HUGETLB_PAGE */ struct hstate {}; @@ -409,6 +419,8 @@ static inline pgoff_t basepage_index(struct page *page) return page->index; } #define dissolve_free_huge_pages(s, e) do {} while (0) +#define pmd_huge_support() 0 +#define hugepage_migration_support(h) 0 #endif /* CONFIG_HUGETLB_PAGE */ #endif /* _LINUX_HUGETLB_H */ diff --git a/mm/migrate.c b/mm/migrate.c index d3137375fa80e401c4ead5db5c60152cfe3f8f7a..61f14a1923fd6044f7435498fd7cc9d0a0eebc9f 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -949,6 +949,16 @@ static int unmap_and_move_huge_page(new_page_t get_new_page, struct page *new_hpage = get_new_page(hpage, private, &result); struct anon_vma *anon_vma = NULL; + /* + * Movability of hugepages depends on architectures and hugepage size. + * This check is necessary because some callers of hugepage migration + * like soft offline and memory hotremove don't walk through page + * tables or check whether the hugepage is pmd-based or not before + * kicking migration. + */ + if (!hugepage_migration_support(page_hstate(hpage))) + return -ENOSYS; + if (!new_hpage) return -ENOMEM;