Buffer Allocation issue when running MoonGen for 100G NIC

[sarsanaee]

Hey,

We are trying to run MoonGen with a 100G Mellonox NIC. However, all examples get a segmentation fault at bufs:alloc line. Is there any idea on this?

Is there something I missed in the setup? I tried to allocate more huge pages or changed the packet size, however, none of these helped!

Thanks, Alireza

[emmericp]

Unfortunately I don't have a 100G Mellanox NIC to test against. But usually the reasopn for seg fault when allocating bufs is that the memory pool ran out of buffers, can you try to increase the size of the mempool?

[sarsanaee]

Hey,

Thanks for the response, by increasing mempool, do you mean I should do something like this? local bufs = mempool:bufArray(64), instead of the default line which is local bufs = mempool:bufArray().

It is pretty weird since the same script works on a 10G Mellanox NIC :)

Thanks in advance, Alireza

[emmericp]

there's an optional first parameter when creating the mempool that specifies the size, default ist 2047:

try this:

memory.createMemPool(65535, function(buf) ... end)

[sarsanaee]

I believe my problem has been resolved. Although the memory allocation wasn't an issue but the OFED version I believe. OFED 4.4 worked properly with the master branch and ubuntu 18.04.

One thing I realized is that OFED 5.1(the newest available OFED) has some issues with DPDK 19.05 branch, and building and linking don't finish.

Thanks, Alireza

[sarsanaee]

I just realized the buffer allocation issue is still there but happens after a few iterations, for instance after a minute or so.

When I use numbers more than 3 local bufs = mempool:bufArray(3) it works for a minute and then crashes with the same seg fault, however, if I don't give input here(local bufs = mempool:bufArray()) it just crashes after 1 iteration.

Thanks, Alireza