Re: 2.6.19-rc1: Volanomark slowdown

On Wed, 2006-11-08 at 23:10 +0100, Olaf Kirch wrote:

In fixing performance issues, the most obvious explanation isn't always
the right one. It's quite possible you're right, sure.

What I'm saying though is that it doesn't rhyme with what I've seen of
Volanomark - we ran 2.6.16 on a 4p Intel box for instance and it didn't
come close to saturating a Gigabit pipe before it maxed out on CPU load.

I am running Volanomark in a loopback mode on a 2P woodcrest box 
(4 cores).  So the configuration is a bit different.  

In my testing, the CPU utilization is at 100%.  So
increase in ACKs will cost CPU to devote more
time to process those ACKs and reduce throughput.

You could count the number of outbound packets dropped on the server.

As I'm running in loopback mode, there are no dropped packets.

Thanks.

Tim