[emmericp]

Isn't a large part of the performance gain from TSO offloading on transmit due to avoiding working with way too many skb's in the kernel? Shouldn't GSO for UDP with proper NIC support give you most of the performance gain?

I'm not sure about the implementation details of GSO and TSO in Linux. But I know a thing or two about the hardware: the Intel Niantic/82599 NICs support UDP transmit segmentation offloading, I've checked the datasheet real quick and it says "Note that current UDP segmentation offload is not supported by any standard OS."

Not sure if this is just an outdated comment in a 10 year old datasheet or if there's some performance to be gained by using this UDP segmentation offload for quick.

Edit: Should have clicked on the link in the article [1] before posting here, UDP segementation offloading is coming to lots of NIC drivers in 5.5.

Always interesting how the hardware often supports way more features than the drivers expose and you suddenly get new hardware features on a 10+ year old NIC model :) (Similar story with IPsec offloading on the Niantic/82599)

[1] https://kernelnewbies.org/Linux_5.5#Networking-1

[richardwhiuk]

TSO and GSO improve network bandwidth, mainly.