* David Miller <davem@xxxxxxxxxxxxx> wrote: > From: Ingo Molnar <mingo@xxxxxxx> > Date: Mon, 17 Nov 2008 22:26:57 +0100 > > > eth->h_proto access. > > Yes, this is the first time a packet is touched on receive. > > > Given that this workload does localhost networking, my guess would be > > that eth->h_proto is bouncing around between 16 CPUs? At minimum this > > read-mostly field should be separated from the bouncing bits. > > It's the packet contents, there is no way to "seperate it". > > And it should be unlikely bouncing on your system under tbench, the > senders and receivers should hang out on the same cpu unless the > something completely stupid is happening. > > That's why I like running tbench with a num_threads command line > argument equal to the number of cpus, every cpu gets the two thread > talking to eachother over the TCP socket. yeah - and i posted the numbers for that too - it's the same throughput, within ~1% of noise. Ingo -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
