> I thought that I already tried to explain this to you. (although
> it could have been on one of those too-much-coffee-days :)
You told me, but I'm far from convinced this is the problem. I think
it's more likely this is a side-effect of a server issue - something
like a lot of dropped packets and retransmits, though not necessarily
> Something strange happens to the clients when NAPI is enabled on
> the Specweb clients. Somehow the start using a lot more CPU.
> The increased idle time on the server is because the _clients_ are
> CPU maxed. I have some preliminary oprofile data for the clients,
> but it appears that this is another case of Specweb code just
> really sucking.
Hmmm ... if you change something on the server, and all the clients
go wild, I'm suspicious of whatever you did to the server. You need
to have a lot more data before leaping to the conclusion that it's
because the specweb client code is crap.
Troy - I think your UP clients weren't anywhere near maxed out on
CPU power, right? Can you take a peek at the clients under NAPI load?
Dave - did you ever try running 4 specweb clients bound to each of
the 4 CPUs in an attempt to make the clients scale better? I'm
suspicious that you're maxing out 4 4-way machines, and Troy's
16 UPs are cruising along just fine.