Re: Dom0 detects no carrier on ixg

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Wed, Dec 14, 2022 at 07:40:53AM -0700, Brook Milligan wrote:
> 
> > On Dec 14, 2022, at 1:39 AM, Manuel Bouyer <bouyer%antioche.eu.org@localhost> wrote:
> > 
> > 55 is ENOBUFS; you don't have enough memory, or more probably enough
> > mbuf clusters
> > 
> > NMBCLUSTERS is computed automatically based on RAM amount, but for a
> > dom0 (which typically has a small portion of the physical RAM allocated),
> > it ends up too low for modern NIC.
> > 
> > I use
> > options NMBCLUSTERS=262144
> 
> Great, I?ll give that a try.
> 
> Do you use this on DomUs as well?  I?m guessing not unless they are low-memory.  However, perhaps this is limited to real NICs and not a problem with virtual ones?

No problem with virtual NICs. The issue is that ixg wants to allocate
mbufs for multiple receive queues, each of them with a large amount of
mbufs. I have in mind that a single ixg instance wants 64k clusters.

> 
> Is the basic idea to increase NMBCLUSTERS whenever a low-memory machine has a modern NIC?

Yes, that's it.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--