pfsense vtnet lack of queues

[A Former User]

Reading the source code here, I think I understand that it says if VTNET_LEGACY_TX is defined then MultiQueue is disabled.

Does anyone know how we can verify what flags pfSense uses when compiling this driver?

[jimp]

sys/dev/virtio/network/if_vtnetvar.h:

#ifdef ALTQ
#define VTNET_LEGACY_TX
#endif

You can have shaping, or you can have queues, but you can't have both on vtnet. Since pfSense uses ALTQ for shaping, that gets defined.

[sheptard]

is altq even relevant with fq_codel now? ;p

Any plans on running parallel releases for those who would rather speed over that form of traffic management

[jimp]

We have talked about shipping both an ALTQ and non-ALTQ kernel/environment but I'm not sure if it will happen. It greatly increases the testing/support workload. Might be something we do in a future release (>=2.5) for those who need the extra performance boost.

[A Former User]

Mystery solved!
Thanks @jimp

[juliokele]

i've tried on pfsense 2.5 with "Enable the ALTQ support for hn NICs." disabled - reboot,
still don't work.

vanilla FreeBSD 12.2:

vtnet0: <VirtIO Networking Adapter> on virtio_pci2
vtnet0: Ethernet address: -
vtnet0: netmap queues/slots: TX 4/256, RX 4/128
000.000768 [ 445] vtnet_netmap_attach       vtnet attached txq=4, txd=256 rxq=4, rxd=128

pfsense 2.5:

vtnet0: <VirtIO Networking Adapter> on virtio_pci1
vtnet0: Ethernet address: -
vtnet0: netmap queues/slots: TX 1/256, RX 1/128
000.000770 [ 445] vtnet_netmap_attach       vtnet attached txq=1, txd=256 rxq=1, rxd=128
vtnet1: <VirtIO Networking Adapter> on virtio_pci2
vtnet1: Ethernet address: -
vtnet1: netmap queues/slots: TX 1/256, RX 1/128
000.000771 [ 445] vtnet_netmap_attach       vtnet attached txq=1, txd=256 rxq=1, rxd=128

What am I missing?

[tibere86]

@julio12345 From what I understand, you cannot have multiqueue and ALTQ enabled at the same time using VirtIO. pfSense has choosen ALTQ.

My question is why aren't the number of netmap slots set to 1024 like they are when using IGB NICs? Why are they set differently TX = 256 and RX = 128?

[juliokele]

@jimp said in pfsense vtnet lack of queues:

We have talked about shipping both an ALTQ and non-ALTQ kernel/environment but I'm not sure if it will happen. It greatly increases the testing/support workload. Might be something we do in a future release (>=2.5) for those who need the extra performance boost.

@jimp any progress on this topic (about shipping both an ALTQ and non-ALTQ kernel/environment)?

[jimp]

No, there hasn't been any progress with that.

[chrcoluk]

@julio12345 I will file a request for this to be changed to ALTQ kernel module instead of compiled in the kernel, then when ALTQ shaping is enabled the module could be simply loaded by pfsense and everything is good.

[GPz1100]

@chrcoluk Any progress/movement on the vtnet queues issue?

[chrcoluk]

@GPz1100 said in pfsense vtnet lack of queues:

@chrcoluk Any progress/movement on the vtnet queues issue?

It was declined, if I remember right they said it was too difficult to do, because it required a recompile instead of a loader flag change.