um_tlb_mark_sync
um_tlb_mark_sync(mm, addr, addr + length);
um_tlb_mark_sync(vma->vm_mm, address, address + PAGE_SIZE);
um_tlb_mark_sync(vma->vm_mm, start, end);
um_tlb_mark_sync(&init_mm, start, end);
um_tlb_mark_sync(mm, vma->vm_start, vma->vm_end);