mbuf layout optimizations

[Fabian Keil]

Jeff Roberson <jroberson at jroberson.net> wrote:

> http://people.freebsd.org/~jeff/mbuf2.diff

> This is a call for testers and feedback on my mbuf layout improvements. 
> I'm trying to decide whether I will push to have these included in 8.0. 
> After reducing the scope slightly from my last patch, I have not 
> encountered any problems.  Kip Macy has also been using it for the past 
> few weeks without issue.
> 
> You should not expect any functional changes from this patch.  The goal 
> is mostly to pave the way fors more sensible mbuf handling in the
> future, although it does offer a few performance benefits.

So far I haven't been able to reproduce the em-related panic I
reported with an earlier version of the patch. I'm not sure if
it was reproducible back then, though.

Fabian