rss: Enable portions of RSS globally to enable symmetric hashing
AcceptedPublic
Actions

Authored by gallatin on Tue, Oct 14, 7:46 PM.

Details

Reviewers

adrian
np
jhb
zlei

Summary

We use the fact that all NICs that support hashing are using the
same hash algorithm and hash key to enable symmetic hashing in
TCP, where a software version of the same hash is used to
establish hashes on outgoing connections.

Diff Detail

Repository

rG FreeBSD src repository

Lint

Lint Skipped

Unit

Tests Skipped

Build Status

Buildable 67773
Build 64656: arc lint + arc unit

Event Timeline

gallatin created this revision.Tue, Oct 14, 7:46 PM

Herald added subscribers: glebius, melifaro, ae, imp. · View Herald TranscriptTue, Oct 14, 7:46 PM

gallatin requested review of this revision.Tue, Oct 14, 7:46 PM

Harbormaster completed remote builds in B67773: Diff 164165.Tue, Oct 14, 7:46 PM

gallatin added reviewers: adrian, np, jhb.Tue, Oct 14, 7:50 PM

gallatin added a reviewer: zlei.Wed, Oct 15, 7:03 PM

gallatin mentioned this in D53091: mlx5: use newly exposed RSS hash key API rather than ad-hoc hashing.Thu, Oct 16, 12:37 PM

gallatin mentioned this in D53100: ena: use newly exposed RSS hash key API rather than ad-hoc hashing.Thu, Oct 16, 12:56 PM

zlei mentioned this in D53101: lio: use newly exposed RSS hash key API rather than ad-hoc hashing.Fri, Oct 17, 2:08 PM

Yup, most multiqueue NICs now just "do" RSS natively whether we want it or not, and the main difference here with RSS defined was whether the configured key or a random key was used, etc.

So exposing the global RSS API for the key management / configuration is fine.

(Eventually I'd like it to be a key we can program in per device and globally, and tweak it all at runtime, but that's later.)

This revision is now accepted and ready to land.Wed, Oct 22, 7:14 PM

Looks good to me.