Terrible NFS performance under 9.2-RELEASE?

[J David]

A few questions as I try to parse the various patches floating around for this.

What's the difference between src/sys/nfsserver and
src/sys/fs/nfsserver?  It looks like maybe the former is for NFSv3 and
the latter is for NFSv4?

If so, these patches appear to be for the NFSv4 server.  Since we are
using the NFSv3 server exclusively, does that mean we would need to do
something similar somewhere in the neighborhood of line 930 of
src/sys/nfsserver/nfs_serv.c?

Also, these patches appear server-side.  To make sure things flow
smoothly, will additional client-side changes be necessary?  There is
some MGET/MCLGET in src/sys/nfsclient/nfs_subs.c.  (The equivalent in
src/sys/fs/nfsclient/nfs_clcomsubs.c appear to be using the
NFSMGET/NFSMCLGET macros, so presumably those are handled?)

In any case, the switch from 2k to 4k mbufs and m_getm2 seems well
worthwhile regardless of whether it addresses this specific issue.  It
should reduce a lot of overhead in many common cases.

If my understanding isn't too far off, I can take a whack at testing
the result, but only on NFSv3.

Thanks!