[Cake] [NetDev-People] 0x19: Talk, mq-cake: Scaling software rate limiting across CPU cores

[Sebastian Moeller]

Hi Toke,


> On 10. Feb 2025, at 11:35, Toke Høiland-Jørgensen <toke at redhat.com> wrote:
> 
> Sebastian Moeller <moeller0 at gmx.de> writes:
> 
>> That sounds most excellent...
>> 
>> This also means that now we need cheap router hardware with > 2 NIC
>> queues and > 2 CPUs ;) (with ingress and egress shaping the current
>> state is that 2 CPUs can be utilised).
> 
> Well, even if there are only 2 CPUs, the MQ version can utilise both of
> those in one direction, which helps for asymmetrical traffic :)

Fair point, I was thinking bi directional saturating traffic on a symmetric link, which I guess is far from the typical use case ;)

> 
>> I wonder, does this work for IFBs as well or only for real hardware
>> NIC queues?
> 
> Yup, you can specify the number of TX queues on an ifb interface when
> creating it (ip link add numtxqueues 2 type ifb).

Great, so this will then work even if the true NIC hardware is not multi-queue capable or does numtxqueues need to be <= true number of NIC queues?

> 
> -Toke
>