>-----Original Message-----
>From: Nishit Shah [mailto:[email protected]]
>Sent: Thursday, March 22, 2012 12:27 AM
>To: [email protected]
>Subject: [E1000-devel] Problem with Intel 82573l bi-directional throughput
>
>
>Hi,
>
>We are testing 82573l bi-directional throughput on linux box with below
>setup.
>
>Setup:
>
>                 Host A                    Machine under test
>             Host B
>             10.10.0.1        10.10.0.254        10.10.1.254
>10.10.1.1
>
>             netperf server is running on both Host A and Host B.
>             eth0 and eth1 are pinned to 2nd core of machine under test.
>
>             From Host A -> Host B:
>                 netperf -t TCP_STREAM -l 3600 -H 10.10.11.1
>
>                 Throughput:    ~950 Mbps
>                 CPU usage on machine under test:    (70% idle, 3.0% hi,
>27% si)

Throughput number looks good.
>                  No errors on interface eth0 and eth1.
>
>             From Host B -> Host A:
>                 netperf -t TCP_STREAM -l 3600 -H 10.10.0.1
>
>                 Throughput:    Expected 1.8 Gbps.
>                 CPU usage on machine under test:    (64% idle, 3.0% hi,
>34% si)

What is the throughput number here?

>                 rx_missed_errors increasing on eth0 and eth1.
>                 tcpdump on Host A and HostB shows below packets.
>                     IN: MPCP, Opcode Pause, length 46
>
>Can anyone help why is it so as I can see CPU is idle by around 60 to 65
>% ?

Well, this depend on what programs and applications are running on the system. 
netperf itself takes negligible cpu cycles to process the data. From the driver 
stand point of view HW DMAed data to memory that does not requires cpu 
interaction at all. When HW needs something, it interrupt the CPU i.e. %hi. 
However, drivers do minimal work in ISR and most of the work done in Software 
IRQ , i.e. your % si. 
Today's cpus are so fast that they complete this work in few cycles and  goes 
back to idle.

I think you are getting rx_missed_error because of the  low bus bandwidth.
Can you provide output of lspci -vvv from your system? Also send me output of 
ethtool -K ethx from both system.

One more thing, TCP_STREAM  bi-directional test may not give you line rate. I 
suggest you to run TCP_RR test instead. TCP_RR calculates transaction rate by 
calculating number of complete transactions exchanged divided by the length of 
time it took to perform those transactions. For example, 

[tushar@tlinux-devel netperf-2.5.0]$ netperf -t TCP_RR -H 192.168.1.8 -fm -- -r 
64k -b 4 
MIGRATED TCP REQUEST/RESPONSE TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to
192.168.1.8 (192.168.1.8) port 0 AF_INET : first burst 4
Local /Remote
Socket Size   Request  Resp.   Elapsed  
Send   Recv   Size     Size    Time     Throughput 
bytes  Bytes  bytes    bytes   secs.    10^6bits/sec   

16384  87380  64000    64000   10.00    1810.74   
16384  87380

You should have burst mode enable in netperf by ./configure --enable-burst.

-Tushar

>
>Configuration of machine under test:
>
>CPU:                        Intel(R) Core(TM)2 Duo CPU     E4300  @
>1.80GHz (2 cores)
>Memory:                  2 GB
>e1000e driver:
>
>     # ethtool -i eth0
>     driver: e1000e
>     version: 1.9.5-NAPI
>     firmware-version: 0.5-7
>     bus-info: 0000:04:00.0
>     #
>     # ethtool -i eth1
>     driver: e1000e
>     version: 1.9.5-NAPI
>     firmware-version: 0.5-7
>     bus-info: 0000:03:00.0
>
>     loaded with default settings.
>     rx and tx buffers increased with from defaults to 2048/2048. (Tried
>various options but no luck.)
>
>Modules loaded:
>         # lsmod
>     Module                  Size  Used by    Not tainted
>     af_packet              15360  0
>     ipv6                  195236  16
>     e1000                 119368  0
>     e1000e                125620  0
>
>lspci:
>
>     # lspci -i ./pci.ids
>     00:00.0 Host bridge: Intel Corporation 82945G/GZ/P/PL Memory
>Controller Hub (rev 02)
>     00:02.0 VGA compatible controller: Intel Corporation 82945G/GZ
>Integrated Graphics Controller (rev 02)
>     00:1c.0 PCI bridge: Intel Corporation 82801G (ICH7 Family) PCI
>Express Port 1 (rev 01)
>     00:1c.1 PCI bridge: Intel Corporation 82801G (ICH7 Family) PCI
>Express Port 2 (rev 01)
>     00:1c.2 PCI bridge: Intel Corporation 82801G (ICH7 Family) PCI
>Express Port 3 (rev 01)
>     00:1c.3 PCI bridge: Intel Corporation 82801G (ICH7 Family) PCI
>Express Port 4 (rev 01)
>     00:1d.0 USB Controller: Intel Corporation 82801G (ICH7 Family) USB
>UHCI #1 (rev 01)
>     00:1d.1 USB Controller: Intel Corporation 82801G (ICH7 Family) USB
>UHCI #2 (rev 01)
>     00:1d.2 USB Controller: Intel Corporation 82801G (ICH7 Family) USB
>UHCI #3 (rev 01)
>     00:1d.3 USB Controller: Intel Corporation 82801G (ICH7 Family) USB
>UHCI #4 (rev 01)
>     00:1d.7 USB Controller: Intel Corporation 82801G (ICH7 Family) USB2
>EHCI Controller (rev 01)
>     00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev e1)
>     00:1f.0 ISA bridge: Intel Corporation 82801GB/GR (ICH7 Family) LPC
>Interface Bridge (rev 01)
>     00:1f.1 IDE interface: Intel Corporation 82801G (ICH7 Family) IDE
>Controller (rev 01)
>     00:1f.2 IDE interface: Intel Corporation 82801GB/GR/GH (ICH7
>Family) Serial ATA Storage Controller IDE (rev 01)
>     00:1f.3 SMBus: Intel Corporation 82801G (ICH7 Family) SMBus
>Controller (rev 01)
>     01:00.0 Ethernet controller: Intel Corporation 82573L Gigabit
>Ethernet Controller
>     02:00.0 Ethernet controller: Intel Corporation 82573L Gigabit
>Ethernet Controller
>     03:00.0 Ethernet controller: Intel Corporation 82573L Gigabit
>Ethernet Controller
>     04:00.0 Ethernet controller: Intel Corporation 82573L Gigabit
>Ethernet Controller
>     05:07.0 Ethernet controller: Intel Corporation 82541GI Gigabit
>Ethernet Controller (rev 05)
>     05:0a.0 Ethernet controller: Intel Corporation 82541GI Gigabit
>Ethernet Controller (rev 05)
>
>Kernel:
>     Vanila:-             2.6.27.45
>     Preemption:-    CONFIG_PREEMPT_VOLUNTARY=y
>     frequency:-        CONFIG_HZ=250
>
>Modules loaded:
>
>     # lsmod
>     Module                  Size  Used by    Not tainted
>     af_packet              15360  0
>     ipv6                  195236  16
>     e1000                 119368  0
>     e1000e                125620  0
>
>Rgds,
>Nishit Shah.
>
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