[Qemu-devel] [QUESTION] How to reduce network latency to improve netperf TCP_RR drastically?

[Like Xu <like.xu@linux.intel.com>]

Hi Michael，

At https://www.linux-kvm.org/page/NetworkingTodo, there is an entry for 
network latency saying:

---
reduce networking latency:
  allow handling short packets from softirq or VCPU context
  Plan:
    We are going through the scheduler 3 times
    (could be up to 5 if softirqd is involved)
    Consider RX: host irq -> io thread -> VCPU thread ->
    guest irq -> guest thread.
    This adds a lot of latency.
    We can cut it by some 1.5x if we do a bit of work
    either in the VCPU or softirq context.
  Testing: netperf TCP RR - should be improved drastically
           netperf TCP STREAM guest to host - no regression
  Contact: MST
---

I am trying to make some contributions to improving netperf TCP_RR.
Could you please share more ideas or plans or implemental details to 
make it happen?

Thanks,
Like Xu