To which cpu(s) were the neptune's interrupts assigned? (grep <ethN> /proc/interrupts)
Several
Which ones?-) I suspect that since it is several that at least answers the MSI_X question right? Or is it possible to have a single device have several MSI interrupts?
Have you tried any tests without any filesystem involvement?
no not yet. I'll try that.
If you decide to go the netperf route, feel free to contact me directly with netperf questions, or via the netperf-talk mailling list on netperf.org.