[dpdk-dev] Rx-errors with testpmd (only 75% line rate)

François-Frédéric Ozog ff at ozog.com
Thu Jan 9 22:21:27 CET 2014


Hi,

Can you check that the threads you use for handling the queues are on the
same socket as the card ?

cat /sys/class/net/<interface name>/device/numa_node

will give you the node.

François-Frédéric

> -----Message d'origine-----
> De : dev [mailto:dev-bounces at dpdk.org] De la part de Michael Quicquaro
> Envoyé : jeudi 9 janvier 2014 20:28
> À : dev at dpdk.org
> Cc : mayhan at mayhan.org
> Objet : [dpdk-dev] Rx-errors with testpmd (only 75% line rate)
> 
> Hello,
> My hardware is a Dell PowerEdge R820:
> 4x Intel Xeon E5-4620 2.20GHz 8 core
> 16GB RDIMM 1333 MHz Dual Rank, x4 - Quantity 16 Intel X520 DP 10Gb DA/SFP+
> 
> So in summary 32 cores @ 2.20GHz and 256GB RAM
> 
> ... plenty of horsepower.
> 
> I've reserved 16 1GB Hugepages
> 
> I am configuring only one interface and using testpmd in rx_only mode to
> first see if I can receive at line rate.
> 
> I am generating traffic on a different system which is running the netmap
> pkt-gen program - generating 64 byte packets at close to line rate.
> 
> I am only able to receive approx. 75% of line rate and I see the Rx-errors
> in the port stats going up proportionally.
> I have verified that all receive queues are being used, but strangely
> enough, it doesn't matter how many queues more than 2 that I use, the
> throughput is the same.  I have verified with 'mpstat -P ALL' that all
> specified cores are used.  The utilization of each core is only roughly
> 25%.
> 
> Here is my command line:
> testpmd -c 0xffffffff -n 4 -- --nb-ports=1 --coremask=0xfffffffe
> --nb-cores=8 --rxd=2048 --txd=2048 --mbcache=512 --burst=512 --rxq=8
> --txq=8 --interactive
> 
> What can I do to trace down this problem?  It seems very similar to a
> thread on this list back in May titled "Best example for showing
> throughput?" where no resolution was ever mentioned in the thread.
> 
> Thanks for any help.
> - Michael



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