Re: [dpdk-users] MLX ConnectX-4 Discarding packets

[Filip Janiszewski <contact@filipjaniszewski.com>]

I ran more tests,

This AMD server is a bit confusing, I can tune it to capture 28Mpps (64
bytes frame) from one single core, so I would assume that using one more
core will at least increase a bit the capture capabilities, but it's
not, 1% more speed and it drops regardless of how many queues are
configured - I've not observed this situation on the Intel server, where
adding more queues/cores scale to higher throughput.

This issue have been verified now with both Mellanox and Intel (810
series, 100GbE) NICs.

Anybody encountered anything similar?

Thanks

Il 9/10/21 3:34 PM, Filip Janiszewski ha scritto:
> Hi,
> 
> I've switched a 100Gbe MLX ConnectX-4 card from an Intel Xeon server to
> an AMD EPYC server (running 75F3 CPU, 256GiB of RAM and PCIe4 lanes),
> and using the same capture software we can't get any faster than 10Gbps,
> when exceeding that speed regardless of the amount of queues configured
> the rx_discards_phy counter starts to raise and packets are lost in huge
> amounts.
> 
> On the Xeon machine, I was able to get easily to 50Gbps with 4 queues.
> 
> Is there any specific DPDK configuration that we might want to setup for
> those AMD servers? The software is DPDK based so I wonder if some build
> option is missing somewhere.
> 
> What else I might want to look for to investigate this issue?
> 
> Thanks
> 

-- 
BR, Filip
+48 666 369 823