Minor cleanup. de_thread()->setmax_mm_hiwater_rss() looks a bit
strange, move it into exec_mmap() which plays with old_mm.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
        if (old_mm) {
                up_read(&old_mm->mmap_sem);
                BUG_ON(active_mm != old_mm);
+               setmax_mm_hiwater_rss(&tsk->signal->maxrss, old_mm);
                mm_update_next_owner(old_mm);
                mmput(old_mm);
                return 0;
        /* we have changed execution domain */
        tsk->exit_signal = SIGCHLD;
 
-       if (current->mm)
-               setmax_mm_hiwater_rss(&sig->maxrss, current->mm);
-
        exit_itimers(sig);
        flush_itimer_signals();