User space checkpoint and restart tool (CRIU) needs the page's change to be soft tracked. This allows to do a pre checkpoint and then dump only touched pages. This is done by using a newly assigned PTE bit (_PAGE_SOFT_DIRTY) when the page is backed in memory, and a new _PAGE_SWP_SOFT_DIRTY bit when the page is swapped out. The _PAGE_SWP_SOFT_DIRTY bit is dynamically put after the swap type in the swap pte. A check is added to ensure that the bit is not overwritten by _PAGE_HPTEFLAGS. Signed-off-by: Laurent Dufour <ldufour@xxxxxxxxxxxxxxxxxx> CC: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx> --- arch/powerpc/Kconfig | 2 ++ arch/powerpc/include/asm/pgtable-ppc64.h | 13 +++++++++-- arch/powerpc/include/asm/pgtable.h | 40 +++++++++++++++++++++++++++++++- arch/powerpc/include/asm/pte-book3e.h | 1 + arch/powerpc/include/asm/pte-common.h | 5 ++-- arch/powerpc/include/asm/pte-hash64.h | 1 + 6 files changed, 57 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 9a7057ec2154..73a4a36a6b38 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -559,6 +559,7 @@ choice config PPC_4K_PAGES bool "4k page size" + select HAVE_ARCH_SOFT_DIRTY if CHECKPOINT_RESTORE && PPC_BOOK3S config PPC_16K_PAGES bool "16k page size" @@ -567,6 +568,7 @@ config PPC_16K_PAGES config PPC_64K_PAGES bool "64k page size" depends on !PPC_FSL_BOOK3E && (44x || PPC_STD_MMU_64 || PPC_BOOK3E_64) + select HAVE_ARCH_SOFT_DIRTY if CHECKPOINT_RESTORE && PPC_BOOK3S config PPC_256K_PAGES bool "256k page size" diff --git a/arch/powerpc/include/asm/pgtable-ppc64.h b/arch/powerpc/include/asm/pgtable-ppc64.h index fa1dfb7f7b48..2738bf4a8c55 100644 --- a/arch/powerpc/include/asm/pgtable-ppc64.h +++ b/arch/powerpc/include/asm/pgtable-ppc64.h @@ -315,7 +315,8 @@ static inline void pte_clear(struct mm_struct *mm, unsigned long addr, static inline void __ptep_set_access_flags(pte_t *ptep, pte_t entry) { unsigned long bits = pte_val(entry) & - (_PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_RW | _PAGE_EXEC); + (_PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_RW | _PAGE_EXEC | + _PAGE_SOFT_DIRTY); #ifdef PTE_ATOMIC_UPDATES unsigned long old, tmp; @@ -354,6 +355,7 @@ static inline void __ptep_set_access_flags(pte_t *ptep, pte_t entry) * We filter HPTEFLAGS on set_pte. \ */ \ BUILD_BUG_ON(_PAGE_HPTEFLAGS & (0x1f << _PAGE_BIT_SWAP_TYPE)); \ + BUILD_BUG_ON(_PAGE_HPTEFLAGS & _PAGE_SWP_SOFT_DIRTY); \ } while (0) /* * on pte we don't need handle RADIX_TREE_EXCEPTIONAL_SHIFT; @@ -371,6 +373,8 @@ static inline void __ptep_set_access_flags(pte_t *ptep, pte_t entry) void pgtable_cache_add(unsigned shift, void (*ctor)(void *)); void pgtable_cache_init(void); + +#define _PAGE_SWP_SOFT_DIRTY (1UL << (SWP_TYPE_BITS + _PAGE_BIT_SWAP_TYPE)) #endif /* __ASSEMBLY__ */ /* @@ -389,7 +393,7 @@ void pgtable_cache_init(void); */ #define _HPAGE_CHG_MASK (PTE_RPN_MASK | _PAGE_HPTEFLAGS | \ _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_SPLITTING | \ - _PAGE_THP_HUGE) + _PAGE_THP_HUGE | _PAGE_SOFT_DIRTY) #ifndef __ASSEMBLY__ /* @@ -513,6 +517,11 @@ static inline pte_t *pmdp_ptep(pmd_t *pmd) #define pmd_mkyoung(pmd) pte_pmd(pte_mkyoung(pmd_pte(pmd))) #define pmd_mkwrite(pmd) pte_pmd(pte_mkwrite(pmd_pte(pmd))) +#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY +#define pmd_soft_dirty(pmd) pte_soft_dirty(pmd_pte(pmd)) +#define pmd_mksoft_dirty(pmd) pte_pmd(pte_mksoft_dirty(pmd_pte(pmd))) +#endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */ + #define __HAVE_ARCH_PMD_WRITE #define pmd_write(pmd) pte_write(pmd_pte(pmd)) diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h index 0717693c8428..88baad3d66e2 100644 --- a/arch/powerpc/include/asm/pgtable.h +++ b/arch/powerpc/include/asm/pgtable.h @@ -38,6 +38,44 @@ static inline int pte_special(pte_t pte) { return pte_val(pte) & _PAGE_SPECIAL; static inline int pte_none(pte_t pte) { return (pte_val(pte) & ~_PTE_NONE_MASK) == 0; } static inline pgprot_t pte_pgprot(pte_t pte) { return __pgprot(pte_val(pte) & PAGE_PROT_BITS); } +#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY +static inline int pte_soft_dirty(pte_t pte) +{ + return pte_val(pte) & _PAGE_SOFT_DIRTY; +} +static inline pte_t pte_mksoft_dirty(pte_t pte) +{ + pte_val(pte) |= _PAGE_SOFT_DIRTY; + return pte; +} + +static inline pte_t pte_swp_mksoft_dirty(pte_t pte) +{ + pte_val(pte) |= _PAGE_SWP_SOFT_DIRTY; + return pte; +} +static inline int pte_swp_soft_dirty(pte_t pte) +{ + return pte_val(pte) & _PAGE_SWP_SOFT_DIRTY; +} +static inline pte_t pte_swp_clear_soft_dirty(pte_t pte) +{ + pte_val(pte) &= ~_PAGE_SWP_SOFT_DIRTY; + return pte; +} + +static inline pte_t pte_clear_flags(pte_t pte, pte_basic_t clear) +{ + pte_val(pte) &= ~clear; + return pte; +} +static inline pmd_t pmd_clear_flags(pmd_t pmd, unsigned long clear) +{ + pmd_val(pmd) &= ~clear; + return pmd; +} +#endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */ + #ifdef CONFIG_NUMA_BALANCING /* * These work without NUMA balancing but the kernel does not care. See the @@ -89,7 +127,7 @@ static inline pte_t pte_mkwrite(pte_t pte) { pte_val(pte) &= ~_PAGE_RO; pte_val(pte) |= _PAGE_RW; return pte; } static inline pte_t pte_mkdirty(pte_t pte) { - pte_val(pte) |= _PAGE_DIRTY; return pte; } + pte_val(pte) |= _PAGE_DIRTY | _PAGE_SOFT_DIRTY; return pte; } static inline pte_t pte_mkyoung(pte_t pte) { pte_val(pte) |= _PAGE_ACCESSED; return pte; } static inline pte_t pte_mkspecial(pte_t pte) { diff --git a/arch/powerpc/include/asm/pte-book3e.h b/arch/powerpc/include/asm/pte-book3e.h index 8d8473278d91..df5581f817f6 100644 --- a/arch/powerpc/include/asm/pte-book3e.h +++ b/arch/powerpc/include/asm/pte-book3e.h @@ -57,6 +57,7 @@ #define _PAGE_HASHPTE 0 #define _PAGE_BUSY 0 +#define _PAGE_SOFT_DIRTY 0 #define _PAGE_SPECIAL _PAGE_SW0 diff --git a/arch/powerpc/include/asm/pte-common.h b/arch/powerpc/include/asm/pte-common.h index 71537a319fc8..1bf670996df5 100644 --- a/arch/powerpc/include/asm/pte-common.h +++ b/arch/powerpc/include/asm/pte-common.h @@ -94,13 +94,14 @@ extern unsigned long bad_call_to_PMD_PAGE_SIZE(void); * pgprot changes */ #define _PAGE_CHG_MASK (PTE_RPN_MASK | _PAGE_HPTEFLAGS | _PAGE_DIRTY | \ - _PAGE_ACCESSED | _PAGE_SPECIAL) + _PAGE_ACCESSED | _PAGE_SPECIAL | _PAGE_SOFT_DIRTY) /* Mask of bits returned by pte_pgprot() */ #define PAGE_PROT_BITS (_PAGE_GUARDED | _PAGE_COHERENT | _PAGE_NO_CACHE | \ _PAGE_WRITETHRU | _PAGE_ENDIAN | _PAGE_4K_PFN | \ _PAGE_USER | _PAGE_ACCESSED | _PAGE_RO | \ - _PAGE_RW | _PAGE_HWWRITE | _PAGE_DIRTY | _PAGE_EXEC) + _PAGE_RW | _PAGE_HWWRITE | _PAGE_DIRTY | \ + _PAGE_EXEC | _PAGE_SOFT_DIRTY) /* * We define 2 sets of base prot bits, one for basic pages (ie, diff --git a/arch/powerpc/include/asm/pte-hash64.h b/arch/powerpc/include/asm/pte-hash64.h index ef612c160da7..19ffd150957f 100644 --- a/arch/powerpc/include/asm/pte-hash64.h +++ b/arch/powerpc/include/asm/pte-hash64.h @@ -19,6 +19,7 @@ #define _PAGE_BIT_SWAP_TYPE 2 #define _PAGE_EXEC 0x0004 /* No execute on POWER4 and newer (we invert) */ #define _PAGE_GUARDED 0x0008 +#define _PAGE_SOFT_DIRTY 0x0010 /* software dirty tracking */ /* We can derive Memory coherence from _PAGE_NO_CACHE */ #define _PAGE_NO_CACHE 0x0020 /* I: cache inhibit */ #define _PAGE_WRITETHRU 0x0040 /* W: cache write-through */ -- 1.9.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. 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