From: Pravin Shelar
...

quoted

I'm not completely convinced this is even necessary.  Seems like you are
wasting cycles copying the frames around when you could probably just
pull the header of the first frame and then use page frages to fill in
the rest.

This is what is done when possible. But skb merging is not always
possible, for example when  MAX_SKB_FRAGS limit is reached. You can
have a look at STT implementation.

If MAX_SKB_FRAGS is reached why not just generate two frames?
Except in pathological cases with a log of small fragments
the linearize is likely to be more expensive than the processing.

	David