freebsd stable - Jun 2018 - Anyone have a summary of what kernel option RSS does ? / netisr oddness .

Hi all
 On a recount 11-STABLE I see that the interaction with netisr and rss has
changed. Forgive me if this is clumsy but I don?t quite get what changes were.

On 10-Stable when I have a solarflare or intel Ixgbe card I would get a kernel
thread per rss queue per card and a netirs queue:bucket thread per cpu ( or
tuned to a value I define < ncpus ) . However on recent 11-STABLE about when
the RSS kernel option was imported or added; I now get one netisr queue:bucket
for the whole system and no tuning effects how many threads are created.

Second part I started looking into the kernel rss option and I wanted the better
understand what it was doing ?  Enabling it and the associate protocol block ?
Option gave me 64 queues and no clear way to tune them or constrain them to the
numa domain of the card companies consuming them I could not find options_rss.h
either .  So is there a commit anyone can direct me to to for more insight? Is
there a write up on it somewhere?

Thanks again . 

---
Mark Saad | nonesuch at longcount.org