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I think access to offload engines is a big part of the appeal of dpdk still, especially for me all the GPUdirect nvidia-only packet steerer. I need to check ab
by touisteur 2mo ago
I think access to offload engines is a big part of the appeal of dpdk still, especially for me all the GPUdirect nvidia-only packet steerer.
I need to check about the af_xdp ecosystem around fragmentation/reassembly in UDP too, every time I needed something there DPDK had it, often with an offload path.
Some silly stuff in DPDK are very useful for testing too (in-memory devices).
Also I'm not clear on the virtualization story on af_xdp, with dpdk I got something working at full blast 400G in VMs with little (but finnicky) work.
- tptacek 2mo agoI am corrected. Thanks! :)
- touisteur 2mo agoI half-wished I'd get Cunningham's law-ed here. I read a bit more and there seems to be some support for tcp and udp offload, https://netdevconf.info/0x17/sessions/talk/tcp-offload-via-af_xdp-sockets-not-your-grandmothers-tcp-offload.html https://netdevconf.info/0x17/sessions/talk/tcp-offload-via-a... but I haven't checked how easy it is to use. A lot of the socket featureset of io_uring seems available in AF_XDP https://docs.kernel.org/networking/af_xdp.html https://docs.kernel.org/networking/af_xdp.html which shows lots of progress since I looked last. To get an idea of what DPDK gives low-level access to there is the overview https://doc.dpdk.org/guides/nics/features.html https://doc.dpdk.org/guides/nics/features.html and my "favorite annual terabit read" https://doc.dpdk.org/guides/nics/mlx5.html#mlx5-net-features https://doc.dpdk.org/guides/nics/mlx5.html#mlx5-net-features for NVIDIA NICs. Broadcom has some fun stuff too. The first time you hit top RX speed (2x400G my latest) with only one busy core (yay DMA engines) is always a thrill.
- tptacek 2mo agoI'm definitely familiar with DPDK, but when I think about it I mostly just think "polling mode driver" and not "offloading".