igb, ALTQ, and a single queue

[uptownVagrant]

Just wanted to share that I needed to set the following on a C2758 with i354 SoC. I was stress testing HFSC+CoDel and FairQ+CoDel configurations and would frequently drop all traffic from 30 seconds to almost 2 minutes during the experiments. Setting the following has proven stable with a stress load consistently applied for the last 48 hours.

hw.igb.num_queues="1"

#Prevents crashes when running a kernel compiled with IGB_LEGACY_TX and ALTQ is in use. see https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=213257#c25

Yes, there is a note here about this but the above is a practical example of the why.