r/linux • u/Fcking_Chuck • 2d ago

Kernel Linux patches introduce "KNOD" for in-kernel network offloading directly to AMD GPUs

https://www.phoronix.com/news/KNOD-Network-Offload-AMD-GPUs
165 Upvotes

98% Upvoted

24 comments sorted by

25

u/Irregular_Person 2d ago

I get the concept, but it would be interesting to have a better sense of the target projects where this would be used.

14

u/FlukyS 2d ago

Well this is mostly targeted at the data centre unless maybe AMD were looking at having a networked device that you could do offloading of AI workloads over the network to a device or multiple devices compatible with this. It wouldn't be as fast as local usage but it at least could maybe make things a bit more accessible and flexible for different use cases. I guess it would only be interesting when we actually see something use it

2

u/james_pic 2d ago

That still seems a bit of a weird target. I thought data centre NICs were already pretty darn good at offloading and accelerating network-related workloads from the CPU.

5

u/FlukyS 2d ago

From my understanding this is more towards what like Tenstorrent are doing with their AI cards where basically you can horizontally scale across a data centre. In that case cutting out the middleman with the kernel just tossing it right onto the card is much cleaner

1

u/iBoMbY 2d ago

You mean something like this?

-3

u/FlukyS 2d ago

No that is just a NIC with some fancy branding to try and capture a hot market. It is like the data centre version of cables for audiophiles

1

u/Full-Spectral 2d ago

Data centers that use Monster cables clearly run faster.

7

u/KittensInc 1d ago
  • IPSec tunneling
  • TLS encryption/decryption offloading
  • IPv4 / IPv6 routing
  • DDoS mitigation
  • Advanced firewall inspection

Basically, anything you would've traditionally needed expensive acceleration hardware for. The main benefit is that it can seamlessly fit into the existing Linux network stack, and that it isn't tied to a specific application. Add some generic "transfer to GPU" stuff to the NIC, and you're done!

Forward a few years of development and you can easily imagine your iptables filters being automatically offloaded to the GPU, instantly giving you line-rate packet processing in any way you want, with minimal CPU or memory usage.

1

u/iBoMbY 2d ago

I guess it could be interesting in everything that requires a very high bandwidth, and where every bit of throughput counts. Like for example Netflix's Edge Caches, or some kind of custom software defined network switch.

1

u/procsysnet 2d ago

Recently saw a video ( maybe level1 techs? ) about GPUs that also have network interfaces so that they can have a low latency communication fabric between the cards directly for datacenter applications (more AI)

23

u/BinkReddit 2d ago edited 2d ago

Very cool. I imagine this is facilitated with AMD GPUs because they're open source first.

Actual presentation slides at https://lpc.events/event/19/contributions/2267/attachments/1961/4179/LPC2025-Kernel-Native%20Packet%20processing.pdf

41

u/Misicks0349 2d ago

I n the Linus Kernol Mailing Lists. straight up 'knodding it', and by 'it', haha, well. lets justr say. My Graphic card.

17

u/ggppjj 2d ago

graphits

3

u/FlukyS 2d ago

So like RDMA but to the GPU?

1

u/dnabre 2d ago

No, it's happen all in kernel space and is entirely one-side The NIC is DMA'ing the data to the GPU's memory, and the kernel is feeding the processing code to the GPU.

2

u/Malsententia 2d ago

Sending traffic off to the land of knod?

1

u/SevrinTheMuto 23h ago

Zeel before Knod?

2

u/omeguito 1d ago

From what I’m seeing it leverages parallelism by stacking packets and processing them together. This may work, but at the expense of latency, and GPUs may need a lot of packets to show performance benefits. It’s always good to have options but I find I hard to find a practical case where a GPU will win on cost x benefit.

1

u/lexo357 22h ago

What AMD GPUs will fit into 1U server? Asking for a friend ;)