[ovs-git] [openvswitch/ovs] 72a5e2: dpif-netdev: Prefetch next packet before miniflow_...

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/openvswitch/ovs
  Commit: 72a5e2b8fc8c7c316c0b9feb96b7be5b19265c7c
      https://github.com/openvswitch/ovs/commit/72a5e2b8fc8c7c316c0b9feb96b7be5b19265c7c
  Author: Daniele Di Proietto <diproiettod at vmware.com>
  Date:   2015-06-15 (Mon, 15 Jun 2015)

  Changed paths:
    M lib/dpif-netdev.c

  Log Message:
  -----------
  dpif-netdev: Prefetch next packet before miniflow_extract().

It appears that miniflow_extract() in emc_processing() spends a lot of
cycles waiting for the packet's data to be read.

Prefetching the next packet's data while parsing removes this delay.
For a single flow pipeline the throughput improves by ~10%.  With a
more realistic pipeline the change has a much smaller effect (~0.5%
improvement)

Signed-off-by: Daniele Di Proietto <diproiettod at vmware.com>
Signed-off-by: Ethan Jackson <ethan at nicira.com>
Acked-by: Ethan Jackson <ethan at nicira.com>