2020-04-29 08:46:57

by Guoyun Sun

Subject: [PATCH v2] mips/mm: Add page soft dirty tracking

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.

Signed-off-by: Guoyun Sun <[email protected]>
---
arch/mips/include/asm/pgtable-bits.h | 20 +++++++++++++--
arch/mips/include/asm/pgtable.h | 48 ++++++++++++++++++++++++++++++++++--
2 files changed, 64 insertions(+), 4 deletions(-)

diff --git a/arch/mips/include/asm/pgtable-bits.h b/arch/mips/include/asm/pgtable-bits.h
index 4da79b8..e26dc41 100644
--- a/arch/mips/include/asm/pgtable-bits.h
+++ b/arch/mips/include/asm/pgtable-bits.h
@@ -55,6 +55,9 @@ enum pgtable_bits {
#if defined(CONFIG_ARCH_HAS_PTE_SPECIAL)
_PAGE_SPECIAL_SHIFT,
#endif
+#if defined(CONFIG_HAVE_ARCH_SOFT_DIRTY)
+ _PAGE_SOFT_DIRTY_SHIFT,
+#endif
};

/*
@@ -84,6 +87,9 @@ enum pgtable_bits {
#if defined(CONFIG_ARCH_HAS_PTE_SPECIAL)
_PAGE_SPECIAL_SHIFT,
#endif
+#if defined(CONFIG_HAVE_ARCH_SOFT_DIRTY)
+ _PAGE_SOFT_DIRTY_SHIFT,
+#endif
};

#elif defined(CONFIG_CPU_R3K_TLB)
@@ -99,6 +105,9 @@ enum pgtable_bits {
#if defined(CONFIG_ARCH_HAS_PTE_SPECIAL)
_PAGE_SPECIAL_SHIFT,
#endif
+#if defined(CONFIG_HAVE_ARCH_SOFT_DIRTY)
+ _PAGE_SOFT_DIRTY_SHIFT,
+#endif

/* Used by TLB hardware (placed in EntryLo) */
_PAGE_GLOBAL_SHIFT = 8,
@@ -125,7 +134,9 @@ enum pgtable_bits {
#if defined(CONFIG_ARCH_HAS_PTE_SPECIAL)
_PAGE_SPECIAL_SHIFT,
#endif
-
+#if defined(CONFIG_HAVE_ARCH_SOFT_DIRTY)
+ _PAGE_SOFT_DIRTY_SHIFT,
+#endif
/* Used by TLB hardware (placed in EntryLo*) */
#if defined(CONFIG_CPU_HAS_RIXI)
_PAGE_NO_EXEC_SHIFT,
@@ -152,6 +163,11 @@ enum pgtable_bits {
#else
# define _PAGE_SPECIAL 0
#endif
+#if defined(CONFIG_HAVE_ARCH_SOFT_DIRTY)
+# define _PAGE_SOFT_DIRTY (1 << _PAGE_SOFT_DIRTY_SHIFT)
+#else
+# define _PAGE_SOFT_DIRTY 0
+#endif

/* Used by TLB hardware (placed in EntryLo*) */
#if defined(CONFIG_XPA)
@@ -269,6 +285,6 @@ static inline uint64_t pte_to_entrylo(unsigned long pte_val)
#define __WRITEABLE (_PAGE_SILENT_WRITE | _PAGE_WRITE | _PAGE_MODIFIED)

#define _PAGE_CHG_MASK (_PAGE_ACCESSED | _PAGE_MODIFIED | \
- _PFN_MASK | _CACHE_MASK)
+ _PAGE_SOFT_DIRTY | _PFN_MASK | _CACHE_MASK)

#endif /* _ASM_PGTABLE_BITS_H */
diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h
index aab0ec1..9b01d2d 100644
--- a/arch/mips/include/asm/pgtable.h
+++ b/arch/mips/include/asm/pgtable.h
@@ -400,7 +400,7 @@ static inline pte_t pte_mkwrite(pte_t pte)

static inline pte_t pte_mkdirty(pte_t pte)
{
- pte_val(pte) |= _PAGE_MODIFIED;
+ pte_val(pte) |= _PAGE_MODIFIED | _PAGE_SOFT_DIRTY;
if (pte_val(pte) & _PAGE_WRITE)
pte_val(pte) |= _PAGE_SILENT_WRITE;
return pte;
@@ -423,6 +423,30 @@ static inline pte_t pte_mkhuge(pte_t pte)
return pte;
}
#endif /* CONFIG_MIPS_HUGE_TLB_SUPPORT */
+
+#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
+static inline bool pte_soft_dirty(pte_t pte)
+{
+ return pte_val(pte) & _PAGE_SOFT_DIRTY;
+}
+#define pte_swp_soft_dirty pte_soft_dirty
+
+static inline pte_t pte_mksoft_dirty(pte_t pte)
+{
+ pte_val(pte) |= _PAGE_SOFT_DIRTY;
+ return pte;
+}
+#define pte_swp_mksoft_dirty pte_mksoft_dirty
+
+static inline pte_t pte_clear_soft_dirty(pte_t pte)
+{
+ pte_val(pte) &= ~(_PAGE_SOFT_DIRTY);
+ return pte;
+}
+#define pte_swp_clear_soft_dirty pte_clear_soft_dirty
+
+#endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */
+
#endif

/*
@@ -576,7 +600,7 @@ static inline pmd_t pmd_mkclean(pmd_t pmd)

static inline pmd_t pmd_mkdirty(pmd_t pmd)
{
- pmd_val(pmd) |= _PAGE_MODIFIED;
+ pmd_val(pmd) |= _PAGE_MODIFIED | _PAGE_SOFT_DIRTY;
if (pmd_val(pmd) & _PAGE_WRITE)
pmd_val(pmd) |= _PAGE_SILENT_WRITE;

@@ -605,6 +629,26 @@ static inline pmd_t pmd_mkyoung(pmd_t pmd)
return pmd;
}

+#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
+static inline int pmd_soft_dirty(pmd_t pmd)
+{
+ return !!(pmd_val(pmd) & _PAGE_SOFT_DIRTY);
+}
+
+static inline pmd_t pmd_mksoft_dirty(pmd_t pmd)
+{
+ pmd_val(pmd) |= _PAGE_SOFT_DIRTY;
+ return pmd;
+}
+
+static inline pmd_t pmd_clear_soft_dirty(pmd_t pmd)
+{
+ pmd_val(pmd) &= ~(_PAGE_SOFT_DIRTY);
+ return pmd;
+}
+
+#endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */
+
/* Extern to avoid header file madness */
extern pmd_t mk_pmd(struct page *page, pgprot_t prot);

--
2.1.0

2020-05-17 08:59:46

by Thomas Bogendoerfer

Subject: Re: [PATCH v2] mips/mm: Add page soft dirty tracking

On Wed, Apr 29, 2020 at 04:44:32PM +0800, Guoyun Sun wrote:
> 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.
>
> Signed-off-by: Guoyun Sun <[email protected]>
> ---
> arch/mips/include/asm/pgtable-bits.h | 20 +++++++++++++--
> arch/mips/include/asm/pgtable.h | 48 ++++++++++++++++++++++++++++++++++--
> 2 files changed, 64 insertions(+), 4 deletions(-)

applied to mips-next.

Thomas.

--
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
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