Merge /spare/repo/linux-2.6/

1 files changed, 15 insertions, 3 deletions

diff --git a/mm/memory.c b/mm/memory.c
index e046b7e4b530..788a62810340 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -498,6 +498,17 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
         unsigned long addr = vma->vm_start;
         unsigned long end = vma->vm_end;
 
+        /*
+         * Don't copy ptes where a page fault will fill them correctly.
+         * Fork becomes much lighter when there are big shared or private
+         * readonly mappings. The tradeoff is that copy_page_range is more
+         * efficient than faulting.
+         */
+        if (!(vma->vm_flags & (VM_HUGETLB|VM_NONLINEAR|VM_RESERVED))) {
+                if (!vma->anon_vma)
+                        return 0;
+        }
+
         if (is_vm_hugetlb_page(vma))
                 return copy_hugetlb_page_range(dst_mm, src_mm, vma);
 
@@ -551,7 +562,8 @@ static void zap_pte_range(struct mmu_gather *tlb, pmd_t *pmd,
                                      page->index > details->last_index))
                                         continue;
                         }
-                        ptent = ptep_get_and_clear(tlb->mm, addr, pte);
+                        ptent = ptep_get_and_clear_full(tlb->mm, addr, pte,
+                                                        tlb->fullmm);
                         tlb_remove_tlb_entry(tlb, pte, addr);
                         if (unlikely(!page))
                                 continue;
@@ -579,7 +591,7 @@ static void zap_pte_range(struct mmu_gather *tlb, pmd_t *pmd,
                         continue;
                 if (!pte_file(ptent))
                         free_swap_and_cache(pte_to_swp_entry(ptent));
-                pte_clear(tlb->mm, addr, pte);
+                pte_clear_full(tlb->mm, addr, pte, tlb->fullmm);
         } while (pte++, addr += PAGE_SIZE, addr != end);
         pte_unmap(pte - 1);
 }
@@ -1944,7 +1956,7 @@ static int do_file_page(struct mm_struct * mm, struct vm_area_struct * vma,
          * Fall back to the linear mapping if the fs does not support
          * ->populate:
          */
-        if (!vma->vm_ops || !vma->vm_ops->populate || 
+        if (!vma->vm_ops->populate ||
                         (write_access && !(vma->vm_flags & VM_SHARED))) {
                 pte_clear(mm, address, pte);
                 return do_no_page(mm, vma, address, write_access, pte, pmd);