Messages in this thread Patch in this message | | | From | "Kirill A. Shutemov" <> | Subject | [PATCH, RFC 2/9] thp: zap_huge_pmd(): zap huge zero pmd | Date | Thu, 9 Aug 2012 12:08:13 +0300 |
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From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
We don't have a real page to zap in huge zero page case. Let's just clear pmd and remove it from tlb.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> --- mm/huge_memory.c | 27 +++++++++++++++++---------- 1 files changed, 17 insertions(+), 10 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 88e0a7a..9dcb9e6 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1071,16 +1071,23 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, struct page *page; pgtable_t pgtable; pgtable = get_pmd_huge_pte(tlb->mm); - page = pmd_page(*pmd); - pmd_clear(pmd); - tlb_remove_pmd_tlb_entry(tlb, pmd, addr); - page_remove_rmap(page); - VM_BUG_ON(page_mapcount(page) < 0); - add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR); - VM_BUG_ON(!PageHead(page)); - tlb->mm->nr_ptes--; - spin_unlock(&tlb->mm->page_table_lock); - tlb_remove_page(tlb, page); + if (is_huge_zero_pmd(*pmd)) { + pmd_clear(pmd); + tlb_remove_pmd_tlb_entry(tlb, pmd, addr); + tlb->mm->nr_ptes--; + spin_unlock(&tlb->mm->page_table_lock); + } else { + page = pmd_page(*pmd); + pmd_clear(pmd); + tlb_remove_pmd_tlb_entry(tlb, pmd, addr); + page_remove_rmap(page); + VM_BUG_ON(page_mapcount(page) < 0); + add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR); + VM_BUG_ON(!PageHead(page)); + tlb->mm->nr_ptes--; + spin_unlock(&tlb->mm->page_table_lock); + tlb_remove_page(tlb, page); + } pte_free(tlb->mm, pgtable); ret = 1; } -- 1.7.7.6
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