New Content #12237open
Add information on ``ifqmaxlen`` to Hardware Tuning and Troubleshooting
Need to add optimization of interface queue length (net.link.ifqmaxlen), see #10311 for details
It looks like this is the source of the 2048 figure given in #10311. Calomel arrives at that by doubling the value of
inline hw.igb.txd, which is exclusive to igb and em network interfaces. It doesn't look like igc, vtnet, mvneta, or ix, have this value or a single equivalent, but devices with those interfaces do show
inline net.link.ifqmaxlen=128 as default. This is in 22.05 on an 1100, 4100, 5100, and KVM-based virtual machine.
Unless there's some other tunable(s) which makes use of
inline net.link.ifqmaxlen on non-(if_em) interfaces, it looks like we need to specify that this only applies to those two network interface types. Is that correct?