Re: [dpdk-dev] Pktgen-DPDK rate and traffic inconsistency problem

["Wodkowski, PawelX" <pawelx.wodkowski@intel.com>]

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Alexandre Frigon
> Sent: Tuesday, January 27, 2015 8:31 PM
> To: dev@dpdk.org
> Subject: [dpdk-dev] Pktgen-DPDK rate and traffic inconsistency problem
> 
> Hi all,
> 
>  I'm using dpdk 1.8 and pktgen-dpdk 2.8 to generate traffic on a back-to-back
> setup both equipped with 82599EB 10-Gigabit NIC.
> The problem is when I start it, pktgen indicates 10000Mbits/s Tx with 64B packet
> size,  but I'm receiving  about 15% of it on the other end.
> This percentage seems to be proportional with the packet size.
> 
> e.g.
> Using nload to read Rx traffic
> Pktgen:	Tx: 10000Mbits/s	==>	Other end: 	Rx 1660 Mbits/s
> 		Rate: 100%
> 		Pkt size: 64B
> 
> 
> e.g 2
> Pktgen:	Tx: 10000Mbits/s	==>	Other end: 	Rx 9385 Mbits/s
> 		Rate: 100%
> 		Pkt size: 1518B
> 
> 
> Pktgen is started with this command on a Xeon(R) CPU E31270 @ 3.40GHz
> ./app/pktgen -c 1f -n 3 --proc-type auto --socket-mem 1024 --file-prefix pg -- -p
> 0x3 -P  -N -m "[1:3].0, [2:4].1"

>From past experience I don't assign more than 1 core per port. It had some
race conditions issues and one core I capable to RX or TX full 10G.
Also check if you assign proper cores/memory for your NICs (the same
NUMA node).

> 
> Is there something I'm not configuring correctly or something I have miss?
> 
> Also, the % rate is  acting strangely since anything above 50% doesn't change
> the Tx rate and anything below is modifying it
> e.g  	Tx:	 10000Mbits/s		5000Mbits/s
> 	%Rate: 	>=50%			25%
> 
> 

Actually I am getting exactly opposite results :)
If I set rate to 50% I get
MBits/s Rx/Tx   :             0/9942             9942/0          9942/9942

For 10%:
MBits/s Rx/Tx   :             0/1997             1997/0          1997/1997

Which is about 2x  set :D

Additionaly I am getting message when "start 0" -> "stop 0" -> "start 0" is issued
PMD: ixgbe_dev_rx_init(): forcing scatter mode

So there is definitely something wrong there but don't know where.
Another issue I encountered is build system that fail when building out-of-tree.

Till this is fixed you can try version 2.7.1 that is working for me.

Pawel