On Mon, 20 Jun 2011, Nicolas Pitre wrote:

quoted

We don't fall into any of these cases, and therefore as you say, we
don't need packed.  Arnd and I have both explained this.  So why do you 
keep arguing that we do need it?

Please show me where I keep arguing that you need it?

Not explicitly perhaps.  But you did write:

Doesn't mean that because it used to work that it is strictly correct.  
Wouldn't be the first time that a GCC upgrade broke the kernel because 
the kernel wasn't describing things properly enough.

which strongly implies that "packed" is needed.  You also wrote:

Yes, but that's a consequence of not being able to access those fields 
in their naturally aligned position anymore.  Hence the addition of the 
align attribute to tell the compiler that we know that the structure is 
still aligned to a certain degree letting the compiler to avoid 
byte-oriented instructions when possible.

which is predicated on the assumption that "packed" is needed.

Alan Stern