1. 28 Feb, 2017 1 commit
  2. 16 Feb, 2017 2 commits
  3. 20 May, 2016 3 commits
  4. 18 May, 2016 1 commit
    • Alessandro Rubini's avatar
      lib/latency: a latency-test engine, to check WR networks · 3edcad86
      Alessandro Rubini authored
      This adds a tool to check the latency in the network. It is selected
      at build time (config) time.  If you select CONFIG_LATENCY_PROBE you
      are then asked for a CONFIG_LATENCY_ETHTYPE.
      
      The sender node sends three frames, as broadcast in that ethertype
      within the current vlan (or no vlan).  The first frame is at priority
      7, the second at priority 6, and the third includes the egress
      timestamps for the former ones. Each group has a sequence number
      and group identifier.
      
      If the tool is built in wrc.bin, every node acts as a receiver. To
      enable a sender issuing the set of frames every 5 seconds, use "ltest 5".
      To disable use "ltest 0".
      
      The receiver prints the measured latency, and warns if it receives
      frames that are not in the proper order, using the sequence and frame
      type fields.
      
      This is a successful run crossing two wr switches:
      
          latency prio7: 5142.775
          latency prio6: 4998.775
          latency prio7: 4822.773
          latency prio6: 5142.773
          latency prio7: 5142.771
          latency prio6: 5286.771
      
      Later on, we'll make the thing less verbose, and we'll have threshold
      to signal a problem if the network went slow. Currently we just print
      all collected data.
      Signed-off-by: Alessandro Rubini's avatarAlessandro Rubini <rubini@gnudd.com>
      3edcad86