pmap_kenter_pa: mapping already present

[Emmanuel Dreyfus <manu%netbsd.org@localhost>]

Hi

I have a -current Xen DOMU that randomly says:
  pmap_kenter_pa: mapping already present

It happens in sys/arch/x86/x86/pmap.c
That seems completely harmless, but in the code there is a comment 
                /* This should not happen */

Is it a realy bug, or should this printf be #ifdef DEBUG ?

-- 
Emmanuel Dreyfus
manu%netbsd.org@localhost