virtio/vtnet driver multiqueue support when using ALTQ

Hello,

i hope this is the right Mailing List for this question.

We are using pfSense Firewalls, which are based on FreeBSD. They compile it with ALTQ included, causing the vtnet driver to not be multiqueue capable, because it checks for ALTQ when compiling. Since we need the speedup of multiqueue capable drivers, and don't use the Features that require ALTQ, I compiled the kernel without ALTQ support and replaced it. This seems to work fine, and I couldn't find any problems with it.

But I fear that this can be unstable, or can cause some weird Problems. So I has the idea of just removing the ALTQ check from the vtnet driver, causing it to always be multiqueue capable, even if ALTQ is still included. This seems to also work fine.

I don't really understand why the vtnet driver does these changes when ALTQ is enabled, as they don't seem related. So I wanted to know if this is "safe", if I just don't use any ALTQ features.

Thanks