[PATCH] lower VM_DONTCOPY total_vm

dup_mmap of a VM_DONTCOPY vma forgot to lower the child's total_vm.  (But
no way does this account for the recent report of total_vm seen too low.)
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

kernel/fork.c

@@ -208,8 +208,10 @@ static inline int dup_mmap(struct mm_struct * mm, struct mm_struct * oldmm)
 		struct file *file;
 
 		if (mpnt->vm_flags & VM_DONTCOPY) {
+			long pages = vma_pages(mpnt);
+			mm->total_vm -= pages;
 			__vm_stat_account(mm, mpnt->vm_flags, mpnt->vm_file,
-							-vma_pages(mpnt));
+								-pages);
 			continue;
 		}
 		charge = 0;