Calculating number of HugeTLBs required

[Stephen Hemminger]

On Tue, 4 Mar 2025 11:22:50 -0800
Patrick Mahan <mahan at mahan.org> wrote:

> Morning,
> 
> This might be simple question, but it has my curiosity itching.
> 
> I did a quick scan through the documentation, but I did not see any good 
> guidelines for determining the number of HugeTLB based on the number of PMDs and 
> number of RX/TX queues.
> 
> I'm am looking at three different platforms, one has 2 ports (ixgbe), one has 3 
> ports (1 e1000 and 2 i40es) and a third has 2 ports (1 e1000 and 1 Cavium liquidIO).
> 
> I'm trying to come up with some means of defining the HugeTLB requirements other 
> than trial and error.
> 
> Thanks,
> 
> Patrick

There is on exact way to estimate this. But for most applications the largest memory footprint
is the mbuf pool. For sizing the mbuf pool you need to account for all the NIC's, queues, and descriptor arrays
as well as any internal staging buffers.