Hi Donald,

Thank you for your reply.

> 
> I have a couple additional questions
>  - What were you running to do this test? (i.e. netperf, pktgen?)

netperf-2.4.2-1.el5.rf

>  - What throughput were you seeing?

On tx side i see almost 10Gb/s, on rx side I see about 5.6 Gb/s

>  - Are both ports plugged into x8 PCIe slots

Yes, both servers are Dell R710 with the same hardware configuration

>  - Did you look at the dmesg for anything relative?

I see no error or warning messages on both side.

>  - Do you see this issue only with UDP?

If I send a TCP stream I see on both side a throughput of about 5.54 
Gb/s and less rx_missed_errors on rx side:

NIC statistics:
      rx_packets: 1768101
      tx_packets: 235384
      rx_bytes: 15937257320
      tx_bytes: 15704254
      lsc_int: 2
      tx_busy: 0
      non_eop_descs: 7072222
      rx_errors: 0
      tx_errors: 0
      rx_dropped: 0
      tx_dropped: 0
      multicast: 1
      broadcast: 0
      rx_no_buffer_count: 0
      collisions: 0
      rx_over_errors: 0
      rx_crc_errors: 0
      rx_frame_errors: 0
      rx_fifo_errors: 0
      rx_missed_errors: 1539
      tx_aborted_errors: 0
      tx_carrier_errors: 0
      tx_fifo_errors: 0
      tx_heartbeat_errors: 0
      tx_timeout_count: 0
      tx_restart_queue: 0
      rx_long_length_errors: 0
      rx_short_length_errors: 0
      tx_tcp4_seg_ctxt: 0
      tx_tcp6_seg_ctxt: 0
      tx_flow_control_xon: 0
      rx_flow_control_xon: 0
      tx_flow_control_xoff: 0
      rx_flow_control_xoff: 0
      rx_csum_offload_good: 1768098
      rx_csum_offload_errors: 0
      tx_csum_offload_ctxt: 11
      low_latency_interrupt: 0
      alloc_rx_page_failed: 0
      alloc_rx_buff_failed: 0
      lro_aggregated: 1760417
      lro_flushed: 375277
      lro_recycled: 1012791
      rx_no_dma_resources: 0
      hw_rsc_count: 0
      rx_flm: 0
      fdir_match: 0
      fdir_miss: 0
      tx_queue_0_packets: 235384
      tx_queue_0_bytes: 15704254
      rx_queue_0_packets: 2
      rx_queue_0_bytes: 120
      rx_queue_1_packets: 8
      rx_queue_1_bytes: 786
      rx_queue_2_packets: 301752
      rx_queue_2_bytes: 2719959436
      rx_queue_3_packets: 562919
      rx_queue_3_bytes: 5074118826
      rx_queue_4_packets: 7
      rx_queue_4_bytes: 726
      rx_queue_5_packets: 15
      rx_queue_5_bytes: 1526
      rx_queue_6_packets: 313901
      rx_queue_6_bytes: 2829476778
      rx_queue_7_packets: 589497
      rx_queue_7_bytes: 5313699122

I guess it's because of TCP flow control.

I remember that the same behavior was triggered by enabling flow control 
on both cards (ethtool -A eth0 rx on tx on autoconf on) but I have to 
wait till Monday to perform another run to test that configuration.

Thanks,

Mirko

> 
> What I'm wondering is if this NIC was receiving faster than it could process 
> them. 
> 
> Thanks,
> -Don Skidmore <[email protected]>
> 
> 
>> -----Original Message-----
>> From: Mirko Corosu [mailto:[email protected]]
>> Sent: Friday, February 19, 2010 5:30 AM
>> To: [email protected]
>> Subject: [E1000-devel] Intel 2598EB 10-Gigabit AT dropped rx packet
>>
>> Dear all,
>>
>> I'm new to this list, if this isn't the right place to post this issue,
>> please let me know.
>>
>> I am testing two Intel 82598EB 10-Gigabit AT network card mounted on two
>> Dell R710 server with Red Hat Enterprise Linux 5.4 installed. The two
>> NICs are directly connected each other (no switch in between).   I am
>> experiencing a problem on the receive side of the connection: I'm sending
>> an UDP stream after having disabled flow control on each card, and about
>> the 60% of the transmitted packets are dropped with a large number of
>> rx_missed_errors. This is what ifconfig and ethtool -S show:
>>
>> [r...@grids2]# ethtool -S eth0
>> NIC statistics:
>>      rx_packets: 1761794
>>      tx_packets: 32
>>      rx_bytes: 14748667944
>>      tx_bytes: 5746
>>      lsc_int: 2
>>      tx_busy: 0
>>      non_eop_descs: 6510828
>>      rx_errors: 0
>>      tx_errors: 0
>>      rx_dropped: 0
>>      tx_dropped: 0
>>      multicast: 2
>>      broadcast: 2
>>      rx_no_buffer_count: 0
>>      collisions: 0
>>      rx_over_errors: 0
>>      rx_crc_errors: 0
>>      rx_frame_errors: 0
>>      rx_fifo_errors: 0
>>      rx_missed_errors: 1148382
>>      tx_aborted_errors: 0
>>      tx_carrier_errors: 0
>>      tx_fifo_errors: 0
>>      tx_heartbeat_errors: 0
>>      tx_timeout_count: 0
>>      tx_restart_queue: 0
>>      rx_long_length_errors: 0
>>      rx_short_length_errors: 0
>>      tx_tcp4_seg_ctxt: 0
>>      tx_tcp6_seg_ctxt: 0
>>      tx_flow_control_xon: 0
>>      rx_flow_control_xon: 0
>>      tx_flow_control_xoff: 0
>>      rx_flow_control_xoff: 0
>>      rx_csum_offload_good: 28
>>      rx_csum_offload_errors: 0
>>      tx_csum_offload_ctxt: 11
>>      low_latency_interrupt: 0
>>      alloc_rx_page_failed: 0
>>      alloc_rx_buff_failed: 0
>>      lro_aggregated: 8
>>      lro_flushed: 8
>>      lro_recycled: 0
>>      rx_no_dma_resources: 0
>>      hw_rsc_count: 0
>>      rx_flm: 0
>>      fdir_match: 0
>>      fdir_miss: 0
>>      tx_queue_0_packets: 32
>>      tx_queue_0_bytes: 5746
>>      rx_queue_0_packets: 2
>>      rx_queue_0_bytes: 120
>>      rx_queue_1_packets: 2
>>      rx_queue_1_bytes: 120
>>      rx_queue_2_packets: 1761762
>>      rx_queue_2_bytes: 14748664800
>>      rx_queue_3_packets: 0
>>      rx_queue_3_bytes: 0
>>      rx_queue_4_packets: 0
>>      rx_queue_4_bytes: 0
>>      rx_queue_5_packets: 14
>>      rx_queue_5_bytes: 1452
>>      rx_queue_6_packets: 7
>>      rx_queue_6_bytes: 726
>>      rx_queue_7_packets: 7
>>      rx_queue_7_bytes: 726
>>
>> [r...@grids2]# ifconfig eth0
>>
>> eth0      Link encap:Ethernet  HWaddr 00:1B:21:4B:C8:BF
>>           inet addr:10.100.100.2  Bcast:10.100.100.255  Mask:255.255.255.0
>>           inet6 addr: fe80::21b:21ff:fe4b:c8bf/64 Scope:Link
>>           UP BROADCAST RUNNING MULTICAST  MTU:9000  Metric:1
>>           RX packets:1761795 errors:0 dropped:1148382 overruns:0 frame:0
>>           TX packets:39 errors:0 dropped:0 overruns:0 carrier:0
>>           collisions:0 txqueuelen:1000
>>           RX bytes:14748668004 (13.7 GiB)  TX bytes:9332 (9.1 KiB)
>>
>> Each interface has the MTU set to 9000, the driver is the one provided
>> by Dell support (ixgbe 2.0.44.14-NAPI) with Rx multiqueue enabled and
>> InterruptThrottleRate set to 8000 (but I tried 16000 and 32000 too).
>> Also I tried to set FdirPballoc parameter to 0, 1 and 2 with no success.
>> Single CPU load is no more than 10% with 8000 interrupt/s:
>>
>> [r...@grids2 ~]# mpstat -P ALL 2
>>
>> 05:16:43 PM  CPU   %user   %nice    %sys %iowait    %irq   %soft  %steal
>> %idle    intr/s
>> 05:16:45 PM  all    0.00    0.00    0.06    0.00    0.06    1.19    0.00
>>    98.69   9018.00
>> 05:16:45 PM    0    0.00    0.00    0.00    0.00    0.00    0.00    0.00
>>   100.00   1002.50
>> 05:16:45 PM    1    0.00    0.00    0.00    0.00    0.00    0.00    0.00
>>   100.00      1.50
>> 05:16:45 PM    2    0.00    0.00    0.50    0.00    0.50    9.45    0.00
>>    89.55   8007.00
>> 05:16:45 PM    3    0.00    0.00    0.00    0.00    0.00    0.00    0.00
>>   100.00      1.00
>> 05:16:45 PM    4    0.00    0.00    0.00    0.00    0.00    0.00    0.00
>>   100.00      1.00
>> 05:16:45 PM    5    0.00    0.00    0.00    0.00    0.00    0.00    0.00
>>   100.00      3.00
>> 05:16:45 PM    6    0.00    0.00    0.00    0.00    0.00    0.00    0.00
>>   100.00      1.00
>> 05:16:45 PM    7    0.00    0.00    0.00    0.00    0.00    0.00    0.00
>>   100.00      1.00
>>
>> I tried to configure smp affinity to assign the IRQ of each
>> rx-queue to a different CPU, with no effect on the amount of dropped
>> packets. I also verified that if I connect the NIC on a 10GE switch and
>> send more than one stream from different servers, the card uses
>> different rx-queues but the problem still exists.
>>
>> I modified the /etc/sysctl.conf file parameters adding:
>>
>> net.core.wmem_max = 16777216
>> net.core.wmem_default = 8388608
>> net.core.rmem_max = 16777216
>> net.core.rmem_default = 8388608
>> net.ipv4.tcp_rmem = 4096 262144 16777216
>> net.ipv4.tcp_wmem = 4096 262144 16777216
>> net.ipv4.tcp_mem = 4096 8388608 16777216
>> net.core.optmem_max = 524288
>> net.core.netdev_max_backlog = 200000
>>
>>
>>
>>
>> Some other details:
>>
>> - CPU: dual quad core Intel L5520  @ 2.27GHz (Hyper-Threading disabled)
>> - RAM: 24 GB (12 X 2GB)
>> - Slot PCI: PCIe gen.2 x8
>> - Kernel linux: 2.6.18-128.1.1.el5 and 2.6.18-164.2.1.el5
>>
>> Any suggestions?
>> Thank you very much in advance.
>>
>> Mirko Corosu
>>
>> --
>>
>> --------------------------------------------------------------------------
>> Mirko Corosu
>> Network and system administrator
>> Computing Center
>> Istituto Nazionale Fisica Nucleare
>> Via Dodecaneso 33
>> 16146 Genova, Italy
>> http://www.ge.infn.it
>> --------------------------------------------------------------------------
>>
>>
>>
>> ---------------------------------------------------------------------------
>> ---
>> Download Intel&#174; Parallel Studio Eval
>> Try the new software tools for yourself. Speed compiling, find bugs
>> proactively, and fine-tune applications for parallel performance.
>> See why Intel Parallel Studio got high marks during beta.
>> http://p.sf.net/sfu/intel-sw-dev
>> _______________________________________________
>> E1000-devel mailing list
>> [email protected]
>> https://lists.sourceforge.net/lists/listinfo/e1000-devel
>> To learn more about Intel&#174; Ethernet, visit
>> http://communities.intel.com/community/wired


-- 

--------------------------------------------------------------------------
Mirko Corosu
Istituto Nazionale Fisica Nucleare
Via Dodecaneso 33
16146 Genova
www.ge.infn.it
Phone +39 010 3536361
--------------------------------------------------------------------------

--------------------------------------------------------------------------
Se tutto sembra venirti incontro, probabilmente sei nella corsia sbagliata.
--------------------------------------------------------------------------


------------------------------------------------------------------------------
Download Intel&#174; Parallel Studio Eval
Try the new software tools for yourself. Speed compiling, find bugs
proactively, and fine-tune applications for parallel performance.
See why Intel Parallel Studio got high marks during beta.
http://p.sf.net/sfu/intel-sw-dev
_______________________________________________
E1000-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/e1000-devel
To learn more about Intel&#174; Ethernet, visit 
http://communities.intel.com/community/wired

Reply via email to