Re: netfront for review

   Hi,

Gerd, in change 11196:b85da7cd9ea5 "front: Fix rx buffer leak when
tearing down an interface." you added a call to
"add_id_to_freelist(np->rx_skbs, id);".  However, rx_skbs doesn't have
an extra entry for the list head, and there's never any corresponding
get_id_from_freelist(np->rx_skbs).  What should it be?

The function has an effect in page flipping mode only.  It walks the 
whole list of rx skbufs (id is the loop variable ...), checks whenever 
they are handed out to the frontend driver to fill in packet data and 
not returned yet, and if so reclaim them ...

quoted

quoted

+	err = xenbus_scanf(XBT_NIL, np->xbdev->otherend,
+			   "feature-rx-flip", "%u", &feature_rx_flip);
+	if (err != 1)
+		feature_rx_flip = 1;
    

This second one deserves a comment.  If it doesn't set feature_rx_flip
it's *on*?  Historical reasons

Guess so.  It defaults to flip.  I simplified the rx_copy/flip module
parameter to a simple rx_mode=0/1, but this is preserved from the
original.  My guess is that originally there was only flip, and copy was
added later.

Yep, page flipping is the old (pre xen 3.0.3) way, copy was added (and 
made the default) later.

cheers,
   Gerd