From e7bb4b6d1609cce391af1e7bc6f31d14f1a3a890 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Thu, 12 Feb 2015 14:58:19 -0800 Subject: [PATCH] mm: add p[te|md] protnone helpers for use by NUMA balancing This is a preparatory patch that introduces protnone helpers for automatic NUMA balancing. Signed-off-by: Mel Gorman Acked-by: Linus Torvalds Acked-by: Aneesh Kumar K.V Tested-by: Sasha Levin Cc: Benjamin Herrenschmidt Cc: Dave Jones Cc: Hugh Dickins Cc: Ingo Molnar Cc: Kirill Shutemov Cc: Paul Mackerras Cc: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/powerpc/include/asm/pgtable.h | 16 ++++++++++++++++ arch/x86/include/asm/pgtable.h | 16 ++++++++++++++++ include/asm-generic/pgtable.h | 20 ++++++++++++++++++++ 3 files changed, 52 insertions(+) diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h index 7e77f2ca5132..1146006d3477 100644 --- a/arch/powerpc/include/asm/pgtable.h +++ b/arch/powerpc/include/asm/pgtable.h @@ -40,6 +40,22 @@ static inline int pte_none(pte_t pte) { return (pte_val(pte) & ~_PTE_NONE_MASK) static inline pgprot_t pte_pgprot(pte_t pte) { return __pgprot(pte_val(pte) & PAGE_PROT_BITS); } #ifdef CONFIG_NUMA_BALANCING +/* + * These work without NUMA balancing but the kernel does not care. See the + * comment in include/asm-generic/pgtable.h . On powerpc, this will only + * work for user pages and always return true for kernel pages. + */ +static inline int pte_protnone(pte_t pte) +{ + return (pte_val(pte) & + (_PAGE_PRESENT | _PAGE_USER)) == _PAGE_PRESENT; +} + +static inline int pmd_protnone(pmd_t pmd) +{ + return pte_protnone(pmd_pte(pmd)); +} + static inline int pte_present(pte_t pte) { return pte_val(pte) & _PAGE_NUMA_MASK; diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 0fe03f834fb1..f519b0b529dd 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -483,6 +483,22 @@ static inline int pmd_present(pmd_t pmd) _PAGE_NUMA); } +#ifdef CONFIG_NUMA_BALANCING +/* + * These work without NUMA balancing but the kernel does not care. See the + * comment in include/asm-generic/pgtable.h + */ +static inline int pte_protnone(pte_t pte) +{ + return pte_flags(pte) & _PAGE_PROTNONE; +} + +static inline int pmd_protnone(pmd_t pmd) +{ + return pmd_flags(pmd) & _PAGE_PROTNONE; +} +#endif /* CONFIG_NUMA_BALANCING */ + static inline int pmd_none(pmd_t pmd) { /* Only check low word on 32-bit platforms, since it might be diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index 129de9204d18..067922c06c29 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -673,6 +673,26 @@ static inline int pmd_trans_unstable(pmd_t *pmd) #endif } +#ifndef CONFIG_NUMA_BALANCING +/* + * Technically a PTE can be PROTNONE even when not doing NUMA balancing but + * the only case the kernel cares is for NUMA balancing and is only ever set + * when the VMA is accessible. For PROT_NONE VMAs, the PTEs are not marked + * _PAGE_PROTNONE so by by default, implement the helper as "always no". It + * is the responsibility of the caller to distinguish between PROT_NONE + * protections and NUMA hinting fault protections. + */ +static inline int pte_protnone(pte_t pte) +{ + return 0; +} + +static inline int pmd_protnone(pmd_t pmd) +{ + return 0; +} +#endif /* CONFIG_NUMA_BALANCING */ + #ifdef CONFIG_NUMA_BALANCING /* * _PAGE_NUMA distinguishes between an unmapped page table entry, an entry that -- 2.20.1