From 29b93c68bf81d2aad1030e989d844cff9f3ba99a Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Sun, 19 May 2013 15:51:03 +0530 Subject: [PATCH] ARC: [mm] Zero page optimization Signed-off-by: Vineet Gupta --- arch/arc/mm/tlb.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/arc/mm/tlb.c b/arch/arc/mm/tlb.c index f60807c2683d..1c91dbc8ddd8 100644 --- a/arch/arc/mm/tlb.c +++ b/arch/arc/mm/tlb.c @@ -433,9 +433,14 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long vaddr_unaligned, { unsigned long vaddr = vaddr_unaligned & PAGE_MASK; unsigned long paddr = pte_val(*ptep) & PAGE_MASK; + struct page *page = pfn_to_page(pte_pfn(*ptep)); create_tlb(vma, vaddr, ptep); + if (page == ZERO_PAGE(0)) { + return; + } + /* * Exec page : Independent of aliasing/page-color considerations, * since icache doesn't snoop dcache on ARC, any dirty @@ -447,7 +452,6 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long vaddr_unaligned, */ if ((vma->vm_flags & VM_EXEC) || addr_not_cache_congruent(paddr, vaddr)) { - struct page *page = pfn_to_page(pte_pfn(*ptep)); int dirty = test_and_clear_bit(PG_arch_1, &page->flags); if (dirty) {