svn commit: r254520 - in head/sys: kern sys

[Peter Grehan]

> I recently tried some experiments to reduce the number of mbuf and
> cluster allocations in a 40G NIC driver.  M_NOFREE and EXT_EXTREF proved
> very useful and the code changes to the kernel were minimal.  See
> user/np/cxl_tuning.  The experiment was quite successful and I was
> planning to bring in most of those changes to HEAD.  I was hoping to get
> some runtime mileage on the approach in general before tweaking the
> ctors/dtors for jumpbo, jumbo9, jumbo16 to allow for an mbuf+refcnt
> within the cluster.  But now M_NOFREE has vanished without a warning...

  I also had a virtualization work-in-progress where static mbufs were 
allocated in the kernel and M_NOFREE set.

  Might be worth sending a prior heads-up for these type of changes.

later,

Peter.