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author | Kirill A. Shutemov <kirill@shutemov.name> | 2014-12-10 15:44:36 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-12-10 17:41:08 -0800 |
commit | c164e038eee805147e95789dddb88ae3b3aca11c (patch) | |
tree | 6e3c5c99920142d46a9acb3d334e58c78d005467 /arch | |
parent | 2314b42db67be30b747122d65c6cd2c85da34538 (diff) | |
download | linux-c164e038eee805147e95789dddb88ae3b3aca11c.tar.bz2 |
mm: fix huge zero page accounting in smaps report
As a small zero page, huge zero page should not be accounted in smaps
report as normal page.
For small pages we rely on vm_normal_page() to filter out zero page, but
vm_normal_page() is not designed to handle pmds. We only get here due
hackish cast pmd to pte in smaps_pte_range() -- pte and pmd format is not
necessary compatible on each and every architecture.
Let's add separate codepath to handle pmds. follow_trans_huge_pmd() will
detect huge zero page for us.
We would need pmd_dirty() helper to do this properly. The patch adds it
to THP-enabled architectures which don't yet have one.
[akpm@linux-foundation.org: use do_div to fix 32-bit build]
Signed-off-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Tested-by: Fengwei Yin <yfw.kernel@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/arm64/include/asm/pgtable.h | 1 | ||||
-rw-r--r-- | arch/powerpc/include/asm/pgtable-ppc64.h | 1 | ||||
-rw-r--r-- | arch/sparc/include/asm/pgtable_64.h | 7 | ||||
-rw-r--r-- | arch/x86/include/asm/pgtable.h | 5 |
4 files changed, 14 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 41a43bf26492..df22314f57cf 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -279,6 +279,7 @@ void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address, #endif /* CONFIG_HAVE_RCU_TABLE_FREE */ #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ +#define pmd_dirty(pmd) pte_dirty(pmd_pte(pmd)) #define pmd_young(pmd) pte_young(pmd_pte(pmd)) #define pmd_wrprotect(pmd) pte_pmd(pte_wrprotect(pmd_pte(pmd))) #define pmd_mksplitting(pmd) pte_pmd(pte_mkspecial(pmd_pte(pmd))) diff --git a/arch/powerpc/include/asm/pgtable-ppc64.h b/arch/powerpc/include/asm/pgtable-ppc64.h index ae153c40ab7c..9b4b1904efae 100644 --- a/arch/powerpc/include/asm/pgtable-ppc64.h +++ b/arch/powerpc/include/asm/pgtable-ppc64.h @@ -467,6 +467,7 @@ static inline pte_t *pmdp_ptep(pmd_t *pmd) } #define pmd_pfn(pmd) pte_pfn(pmd_pte(pmd)) +#define pmd_dirty(pmd) pte_dirty(pmd_pte(pmd)) #define pmd_young(pmd) pte_young(pmd_pte(pmd)) #define pmd_mkold(pmd) pte_pmd(pte_mkold(pmd_pte(pmd))) #define pmd_wrprotect(pmd) pte_pmd(pte_wrprotect(pmd_pte(pmd))) diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h index bfeb626085ac..1ff9e7864168 100644 --- a/arch/sparc/include/asm/pgtable_64.h +++ b/arch/sparc/include/asm/pgtable_64.h @@ -667,6 +667,13 @@ static inline unsigned long pmd_pfn(pmd_t pmd) } #ifdef CONFIG_TRANSPARENT_HUGEPAGE +static inline unsigned long pmd_dirty(pmd_t pmd) +{ + pte_t pte = __pte(pmd_val(pmd)); + + return pte_dirty(pte); +} + static inline unsigned long pmd_young(pmd_t pmd) { pte_t pte = __pte(pmd_val(pmd)); diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index aa97a070f09f..081d6f45e006 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -99,6 +99,11 @@ static inline int pte_young(pte_t pte) return pte_flags(pte) & _PAGE_ACCESSED; } +static inline int pmd_dirty(pmd_t pmd) +{ + return pmd_flags(pmd) & _PAGE_DIRTY; +} + static inline int pmd_young(pmd_t pmd) { return pmd_flags(pmd) & _PAGE_ACCESSED; |