bad NFS/UDP performance

[Danny Braniss]

> On Fri, 26 Sep 2008, Danny Braniss wrote:
> 
> > after more testing, it seems it's related to changes made between Aug 4 and 
> > Aug 29 ie, a kernel built on Aug 4 works fine, Aug 29 is slow. I'l now try 
> > and close the gap.
> 
> I think this is the best way forward -- skimming August changes, there are a 
> number of candidate commits, including retuning of UDP hashes by mav, my 
> rwlock changes, changes to mbuf chain handling, etc.

it more difficult than I expected.
for one, the kernel date was missleading, the actual source update is the key, so
the window of changes is now 28/July to 19/August. I have the diffs, but nothing
yet seems relevant.

on the other hand, I tried NFS/TCP, and there things seem ok, ie the 'good' and the 'bad'
give the same throughput, which seem to point to UDP changes ...

danny