* Anthony Liguori (anthony@xxxxxxxxxxxxx) wrote: > The "poor" packet latency of virtio-net is a result of the fact that we > do software timer based TX mitigation. We do this such that we can > decrease the number of exits per-packet and increase throughput. We set > a timer for 250ms and per-packet latency will be at least that much. Actually that's 150us ;-) It's the AlacrityVM numbers that show 250us (note micro, not milli) for latency. That makes sense, shave off 150us for the timer and you're left w/ 100us, which is not substantially slower than what we see (for that bare metal latency we see ~60us) when we switched tx mitigation schemes from timer based to thread scheduling. Quite similar to the 56.8us that vbus/venet shows. thanks, -chris -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
