Posted in software

Core Cost of Doing a Business

A couple of Intel folks gave a talk on the cost of using a core for the business of networking. Some key points to take away are:

  1. For a packet that hits the kernel fast path, on an average 1900 cycles are spent – they say even this is expensive
  2. When the packet misses fast path, it takes about 25000 cycles!! Which is 13x more costly
  3. Caches do matter! They are game changers.
  4. Even if we use a hardware accelerator, the worst case performance is same as that of a software data plane, because of the misses
  5. Surprisingly, even if we increase the number of cores allocated to handle miss processing, the performance does not increase!!
  6. Moving to OVS+DPDK has increased the performance from 1.3 MPPS to 25 MPPS, but still cannot beat a hardware accelerated environment. The performance improvement is because of avoiding frequent context switches between kernel and user space.
  7. Every core that is freed up from network services, is a core that goes to the revenue generating application
  8. Hardware offload of network services on a server is the coming future. It increases performance, is cost effective and generates more revenue.