On (12/02/15 12:41), David Laight wrote: > > Also what/how are you measuring cpu use. > I'm not sure anything on Linux gives you a truly accurate value > when processes are running for very short periods. I was using mpstat, while running iperf. Should I be using something else? or running it for longer intervals? but I hope we are not doomed at 1 Gbps, or else security itself would come at a very unattractive cost. Anyway, even aside from crypto. we need to have some way to add TCP options (that depend on the contents of the tcp header) etc post-GSO, in the interest of not ossifying the stack. > On an SMP system you also get big effects when work is switched > between cpus. I've got some tests that run a lot faster if I > put all but one of the cpus into a busy-loop in userspace > (eg: while :; do :; done)! yes Rick Jones also pointed the same thing to me, and one of the things I was going to try out later today is to instrument the effects of pinning irqs and iperf threads to a specific cpu. --Sowmini -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
