> I've resynced the blkback threading patch with the latest sparse tree, 
> here we are.  Changes:
> 
>   * One thread per blkif.  The I/O scheduler can do a better job that
>     way, also you can use ionice on the blkback threads to adjust the
>     block I/O priorities for the domain.
>   * Various stuff has been moved from global variables into blkif_t.
>   * The scary allocation ring for pending_req's is gone and has been
>     replaced by a free list.
>   * made dispatch_rw_block_io() reentrant.
>   * general linux coding style cleanup, at least for the code I've
>     touched anyway.
>   * number of outstanding requests is runtime-configurable now.
>   * made the ia64 #ifdefs smaller and dropped one.  It should still
>     work on ia64 in theory, but would be great if the ia64 folks
>     can have a look ...

Next version of that patch, with those additional changes:

   * re-added the xen_init() which got lost by mistake (pointed
     out by the ia64 guys).
   * adapted to the driver architecture changes merged recently.

cheers,

   Gerd