Messages in this thread Patch in this message | | | From | "Kirill A. Shutemov" <> | Subject | [PATCH v6 08/12] thp: setup huge zero page on non-write page fault | Date | Thu, 15 Nov 2012 21:26:58 +0200 |
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From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
All code paths seems covered. Now we can map huge zero page on read page fault.
We setup it in do_huge_pmd_anonymous_page() if area around fault address is suitable for THP and we've got read page fault.
If we fail to setup huge zero page (ENOMEM) we fallback to handle_pte_fault() as we normally do in THP.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> --- mm/huge_memory.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 015a13a..ca3f6f2 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -726,6 +726,16 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, return VM_FAULT_OOM; if (unlikely(khugepaged_enter(vma))) return VM_FAULT_OOM; + if (!(flags & FAULT_FLAG_WRITE)) { + pgtable_t pgtable; + pgtable = pte_alloc_one(mm, haddr); + if (unlikely(!pgtable)) + goto out; + spin_lock(&mm->page_table_lock); + set_huge_zero_page(pgtable, mm, vma, haddr, pmd); + spin_unlock(&mm->page_table_lock); + return 0; + } page = alloc_hugepage_vma(transparent_hugepage_defrag(vma), vma, haddr, numa_node_id(), 0); if (unlikely(!page)) { -- 1.7.11.7
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