On Fri, 30 May 2014, Naoya Horiguchi wrote:
> Curretly hugepage migration is available for all archs which support pmd-level
> hugepage, but testing is done only for x86_64 and there're bugs for other archs.
> So to avoid breaking such archs, this patch limits the availability strictly to
> x86_64 until developers of other archs get interested in enabling this feature.
>
> Simply disabling hugepage migration on non-x86_64 archs is not enough to fix
> the reported problem where sys_move_pages() hits the BUG_ON() in
> follow_page(FOLL_GET), so let's fix this by checking if hugepage migration is
> supported in vma_migratable().
>
> ChangeLog:
> - add VM_HUGETLB check in vma_migratable()
> - fix dependency in config ARCH_ENABLE_HUGEPAGE_MIGRATION
> - remove comment on hugepage_migration_support()
>
> Reported-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> Tested-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx # 3.12+
Acked-by: Hugh Dickins <hughd@xxxxxxxxxx>
> ---
> arch/arm/mm/hugetlbpage.c | 5 -----
> arch/arm64/mm/hugetlbpage.c | 5 -----
> arch/ia64/mm/hugetlbpage.c | 5 -----
> arch/metag/mm/hugetlbpage.c | 5 -----
> arch/mips/mm/hugetlbpage.c | 5 -----
> arch/powerpc/mm/hugetlbpage.c | 10 ----------
> arch/s390/mm/hugetlbpage.c | 5 -----
> arch/sh/mm/hugetlbpage.c | 5 -----
> arch/sparc/mm/hugetlbpage.c | 5 -----
> arch/tile/mm/hugetlbpage.c | 5 -----
> arch/x86/Kconfig | 4 ++++
> arch/x86/mm/hugetlbpage.c | 10 ----------
> include/linux/hugetlb.h | 13 +++++--------
> include/linux/mempolicy.h | 6 ++++++
> mm/Kconfig | 3 +++
> 15 files changed, 18 insertions(+), 73 deletions(-)
>
> diff --git v3.15-rc5.orig/arch/arm/mm/hugetlbpage.c v3.15-rc5/arch/arm/mm/hugetlbpage.c
> index 54ee6163c181..66781bf34077 100644
> --- v3.15-rc5.orig/arch/arm/mm/hugetlbpage.c
> +++ v3.15-rc5/arch/arm/mm/hugetlbpage.c
> @@ -56,8 +56,3 @@ 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 v3.15-rc5.orig/arch/arm64/mm/hugetlbpage.c v3.15-rc5/arch/arm64/mm/hugetlbpage.c
> index 5e9aec358306..2fc8258bab2d 100644
> --- v3.15-rc5.orig/arch/arm64/mm/hugetlbpage.c
> +++ v3.15-rc5/arch/arm64/mm/hugetlbpage.c
> @@ -54,11 +54,6 @@ 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 v3.15-rc5.orig/arch/ia64/mm/hugetlbpage.c v3.15-rc5/arch/ia64/mm/hugetlbpage.c
> index 68232db98baa..76069c18ee42 100644
> --- v3.15-rc5.orig/arch/ia64/mm/hugetlbpage.c
> +++ v3.15-rc5/arch/ia64/mm/hugetlbpage.c
> @@ -114,11 +114,6 @@ 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 v3.15-rc5.orig/arch/metag/mm/hugetlbpage.c v3.15-rc5/arch/metag/mm/hugetlbpage.c
> index 042431509b56..3c52fa6d0f8e 100644
> --- v3.15-rc5.orig/arch/metag/mm/hugetlbpage.c
> +++ v3.15-rc5/arch/metag/mm/hugetlbpage.c
> @@ -110,11 +110,6 @@ 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 v3.15-rc5.orig/arch/mips/mm/hugetlbpage.c v3.15-rc5/arch/mips/mm/hugetlbpage.c
> index 77e0ae036e7c..4ec8ee10d371 100644
> --- v3.15-rc5.orig/arch/mips/mm/hugetlbpage.c
> +++ v3.15-rc5/arch/mips/mm/hugetlbpage.c
> @@ -84,11 +84,6 @@ 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 v3.15-rc5.orig/arch/powerpc/mm/hugetlbpage.c v3.15-rc5/arch/powerpc/mm/hugetlbpage.c
> index eb923654ba80..7e70ae968e5f 100644
> --- v3.15-rc5.orig/arch/powerpc/mm/hugetlbpage.c
> +++ v3.15-rc5/arch/powerpc/mm/hugetlbpage.c
> @@ -86,11 +86,6 @@ 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)
> {
> @@ -106,11 +101,6 @@ 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 v3.15-rc5.orig/arch/s390/mm/hugetlbpage.c v3.15-rc5/arch/s390/mm/hugetlbpage.c
> index 0727a55d87d9..0ff66a7e29bb 100644
> --- v3.15-rc5.orig/arch/s390/mm/hugetlbpage.c
> +++ v3.15-rc5/arch/s390/mm/hugetlbpage.c
> @@ -220,11 +220,6 @@ 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 v3.15-rc5.orig/arch/sh/mm/hugetlbpage.c v3.15-rc5/arch/sh/mm/hugetlbpage.c
> index 0d676a41081e..d7762349ea48 100644
> --- v3.15-rc5.orig/arch/sh/mm/hugetlbpage.c
> +++ v3.15-rc5/arch/sh/mm/hugetlbpage.c
> @@ -83,11 +83,6 @@ 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 v3.15-rc5.orig/arch/sparc/mm/hugetlbpage.c v3.15-rc5/arch/sparc/mm/hugetlbpage.c
> index 9bd9ce80bf77..d329537739c6 100644
> --- v3.15-rc5.orig/arch/sparc/mm/hugetlbpage.c
> +++ v3.15-rc5/arch/sparc/mm/hugetlbpage.c
> @@ -231,11 +231,6 @@ 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 v3.15-rc5.orig/arch/tile/mm/hugetlbpage.c v3.15-rc5/arch/tile/mm/hugetlbpage.c
> index 0cb3bbaa580c..e514899e1100 100644
> --- v3.15-rc5.orig/arch/tile/mm/hugetlbpage.c
> +++ v3.15-rc5/arch/tile/mm/hugetlbpage.c
> @@ -166,11 +166,6 @@ 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 v3.15-rc5.orig/arch/x86/Kconfig v3.15-rc5/arch/x86/Kconfig
> index 25d2c6f7325e..6b8b429c832f 100644
> --- v3.15-rc5.orig/arch/x86/Kconfig
> +++ v3.15-rc5/arch/x86/Kconfig
> @@ -1871,6 +1871,10 @@ config ARCH_ENABLE_SPLIT_PMD_PTLOCK
> def_bool y
> depends on X86_64 || X86_PAE
>
> +config ARCH_ENABLE_HUGEPAGE_MIGRATION
> + def_bool y
> + depends on X86_64 && HUGETLB_PAGE && MIGRATION
> +
> menu "Power management and ACPI options"
>
> config ARCH_HIBERNATION_HEADER
> diff --git v3.15-rc5.orig/arch/x86/mm/hugetlbpage.c v3.15-rc5/arch/x86/mm/hugetlbpage.c
> index 8c9f647ff9e1..8b977ebf9388 100644
> --- v3.15-rc5.orig/arch/x86/mm/hugetlbpage.c
> +++ v3.15-rc5/arch/x86/mm/hugetlbpage.c
> @@ -58,11 +58,6 @@ follow_huge_pmd(struct mm_struct *mm, unsigned long address,
> {
> return NULL;
> }
> -
> -int pmd_huge_support(void)
> -{
> - return 0;
> -}
> #else
>
> struct page *
> @@ -80,11 +75,6 @@ int pud_huge(pud_t pud)
> {
> return !!(pud_val(pud) & _PAGE_PSE);
> }
> -
> -int pmd_huge_support(void)
> -{
> - return 1;
> -}
> #endif
>
> #ifdef CONFIG_HUGETLB_PAGE
> diff --git v3.15-rc5.orig/include/linux/hugetlb.h v3.15-rc5/include/linux/hugetlb.h
> index 63214868c5b2..c9de64cf288d 100644
> --- v3.15-rc5.orig/include/linux/hugetlb.h
> +++ v3.15-rc5/include/linux/hugetlb.h
> @@ -385,15 +385,13 @@ 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);
> +#ifdef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
> + return huge_page_shift(h) == PMD_SHIFT;
> +#else
> + return 0;
> +#endif
> }
>
> static inline spinlock_t *huge_pte_lockptr(struct hstate *h,
> @@ -443,7 +441,6 @@ 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
>
> static inline spinlock_t *huge_pte_lockptr(struct hstate *h,
> diff --git v3.15-rc5.orig/include/linux/mempolicy.h v3.15-rc5/include/linux/mempolicy.h
> index 3c1b968da0ca..f230a978e6ba 100644
> --- v3.15-rc5.orig/include/linux/mempolicy.h
> +++ v3.15-rc5/include/linux/mempolicy.h
> @@ -175,6 +175,12 @@ static inline int vma_migratable(struct vm_area_struct *vma)
> {
> if (vma->vm_flags & (VM_IO | VM_PFNMAP))
> return 0;
> +
> +#ifndef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
> + if (vma->vm_flags & VM_HUGETLB)
> + return 0;
> +#endif
> +
> /*
> * Migration allocates pages in the highest zone. If we cannot
> * do so then migration (at least from node to node) is not
> diff --git v3.15-rc5.orig/mm/Kconfig v3.15-rc5/mm/Kconfig
> index ebe5880c29d6..1e22701c972b 100644
> --- v3.15-rc5.orig/mm/Kconfig
> +++ v3.15-rc5/mm/Kconfig
> @@ -264,6 +264,9 @@ config MIGRATION
> pages as migration can relocate pages to satisfy a huge page
> allocation instead of reclaiming.
>
> +config ARCH_ENABLE_HUGEPAGE_MIGRATION
> + boolean
> +
> config PHYS_ADDR_T_64BIT
> def_bool 64BIT || ARCH_PHYS_ADDR_T_64BIT
>
> --
> 1.9.3
>
>
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