a preliminary report of NET_MPSAFE bridge and if_wm multiqueue PoC performance

[Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>]

Hi,

I wrote if_wm multiqueue PoC using my MSI/MSI-X prototype.
# Here is MSI/MSI-X prototype memo
#     http://mail-index.netbsd.org/tech-kern/2014/11/07/msg017897.html

Here is the PoC, which include ozaki-r@n.o's work NET_MPSAFE if_bridge code.
    https://github.com/knakahara/netbsd-src/tree/k-nakahara-work/if_wm-bridge-measurement
# Because I haven't written xen support code, this code cannot release build...

Furthermore, I measured the performance of the kernel, which is built
above code with enabling "options NET_MPSAFE"("NET_MPSAFE PoC kernel").
The measurement environment is below.
    + Device under target (DUT)
      + supermicro A1SRi-2758F
        - 8core Atom C2578
        - I354 ethernet controller x4
    - DUT used as bridge between 2 NIC
    - The traffic is bi-directional UDP over DUT

Here is the preliminary report.
    http://www.netbsd.org/~knakahara/bridge-mpsafe/Mbps.png
The meaning of the graphs is below.
    + horizontal axis is packet size
      - from 74 byte to 1508 byte
      - vertical axis is mesurement results(Mbps)

    + the meaning of each line graph
      + red graph("MPSAFE-8core-Mbps.dat")
        - the kernel is "NET_MPSAFE PoC kernel"
        - using 8 core by dstributing each 1 NIC queue to other cores
      + green graph("MPSAFE-4core-Mbps.dat")
        - the kernel is "NET_MPSAFE kernel"
        - using 4 core by dstributing each 2 NIC queue to other cores
      + blue graph("MPSAFE-2core-Mbps.dat")
        - the kernel is "NET_MPSAFE PoC kernel"
        - using 2 core by dstributing each 4 NIC queue to other cores
      + green graph("MPSAFE-1core-Mbps.dat")
        - the kernel is "NET_MPSAFE PoC kernel"
        - using only 1 core by centralizing all NIC queues to one core
      + light blue graph("GENERIC-Mbps.dat")
        - the kernel to build the plain NetBSD-current code at Jan 07
        - of course, using only 1 core

We will report more details in AsiaBSDCon 2015, if our submission is
accepted. :)


Thanks,

-- 
//////////////////////////////////////////////////////////////////////
Internet Initiative Japan Inc.

Device Engineering Section,
Core Product Development Department,
Product Division,
Technology Unit

Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>