Hi Alasdair, you removed the hook for end_io from the path selector interface. Unfortunately I need this hook for round-robing path selector. This selector needs to be called for every started and finished I/O for bookkeeping. This is also a reason that this selector should be called every time I/O is maped and not only for every n'th I/O. Could you please put the end_io hook back into the interface? /Stefan Bader