Messages in this thread Patch in this message | | | From | Catalin Marinas <> | Subject | [PATCH] mm: Flush the TLB for a single address in a huge page | Date | Wed, 22 Jul 2015 18:13:34 +0100 |
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When the page table entry is a huge page (and not a table), there is no need to flush the TLB by range. This patch changes flush_tlb_range() to flush_tlb_page() in functions where we know the pmd entry is a huge page.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrea Arcangeli <aarcange@redhat.com> ---
Hi,
That's just a minor improvement but it saves iterating over each small page in a huge page when a single TLB entry is used (we already have a similar assumption in __tlb_adjust_range).
Thanks.
mm/pgtable-generic.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c index 6b674e00153c..ff17eca26211 100644 --- a/mm/pgtable-generic.c +++ b/mm/pgtable-generic.c @@ -67,7 +67,7 @@ int pmdp_set_access_flags(struct vm_area_struct *vma, VM_BUG_ON(address & ~HPAGE_PMD_MASK); if (changed) { set_pmd_at(vma->vm_mm, address, pmdp, entry); - flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE); + flush_tlb_page(vma, address); } return changed; #else /* CONFIG_TRANSPARENT_HUGEPAGE */ @@ -101,7 +101,7 @@ int pmdp_clear_flush_young(struct vm_area_struct *vma, #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ young = pmdp_test_and_clear_young(vma, address, pmdp); if (young) - flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE); + flush_tlb_page(vma, address); return young; } #endif @@ -128,7 +128,7 @@ pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma, unsigned long address, VM_BUG_ON(address & ~HPAGE_PMD_MASK); VM_BUG_ON(!pmd_trans_huge(*pmdp)); pmd = pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp); - flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE); + flush_tlb_page(vma, address); return pmd; } #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ @@ -143,7 +143,7 @@ void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address, VM_BUG_ON(address & ~HPAGE_PMD_MASK); set_pmd_at(vma->vm_mm, address, pmdp, pmd); /* tlb flush only to serialize against gup-fast */ - flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE); + flush_tlb_page(vma, address); } #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ #endif @@ -195,7 +195,7 @@ void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address, { pmd_t entry = *pmdp; set_pmd_at(vma->vm_mm, address, pmdp, pmd_mknotpresent(entry)); - flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE); + flush_tlb_page(vma, address); } #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ #endif
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