Galois Fields New Instructions - Method for Calculating Toeplitz Hash Using GFNI Technology Guide
Last Updated: May 20, 2022
The Toeplitz hash function is used for hash calculation to distribute packets across the queues with RSS (Receive Side Scaling) in Ethernet devices. The Toeplitz hash function is frequently implemented in hardware of modern Network Interface Cards (NIC) but it can also be used to calculate hash values in software use cases. Software implementations of the Toeplitz hash function require a lot of CPU cycles, and calculation time is non-deterministic, for example due to the multiple branching involved in different implementations. The proposed solution outlined in this guide allows the elimination of branches and dramatically reduces the number of CPU cycles needed to calculate the Toeplitz hash signature.