[dpdk-users] Multi-process DPDK application: only one process receiving packets

["Girard, Guillaume" <guillaume.girard@intel.com>]

Hi,

I'm battling with some strange DPDK multi-process behavior, so any help would be appreciated.

I have built a "data sink" application with DPDK. It listens to certain streams of packets and report statistics on those. The application works with a specific Ethernet port specified at the command-line. To listen to multiple ports at once, I made the application Primary/Secondary aware, so if you start the first one as primary, and the others as secondary, it all works fine. I tested this on two machines with Intel X550T cards (ixgbe driver), and I can listen to traffic on as many ports as I have (4x2=8 in my case), with 8 applications in parallel.

Then I moved to another machine, which has X722 ports (i40e driver). That breaks my data-sink in the following way: only one application receives packets. That  is:
(1)  ./data-sink --proc=primary <args>       <- receives packets
(2)  ./data-sink --proc=secondary <args>     <- no packets

I know the invocation of the application is fine, because if I simply run (2) alone with -proc=primary, then I receive traffic on the second port as expected.

I also tried to run them without any connection to one another:
./data-sink --proc=primary -m 1024 -file-prefix=d0 <args>
./data-sink --proc=primary -m 1024 -file-prefix=d1 <args>
And I still get only one application receiving packets (the second one, this time).

When I say "no packets", I should qualify that a bit. I do get packets from time to time. They are just filled with 0, with size varying from 60 to 300 bytes. I get no meaningful packets (ARP request, ping, actual traffic, etc.).

The X772T ports are 4 PCI functions on the same device - I don't know if that makes a difference, but in the X550T, I had two functions per device with no issue. I tested that with DPDK 17.11.2 and DPDK 18.02.2 and obtained the exact same behavior. I retested on my original hardware, and my code works fine there. I did disable ASLR as recommended in the documentation.

Any suggestion on what I could check?

Best regards,
Guillaume Girard

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