Re: Periodic messages on NetBSD-9 and -current: xennet0: rx no cluster

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

On Thu, Jun 23, 2022 at 12:29:11PM -0700, Brian Buhrow wrote:
> 	Hello.  I'm running a number of NetBSD-9 and -current as of 99.77 amd/64 domu machines on
> a couple of different servers with FreeBSD as dom0.  I'm getting the following messages from
> the kernel: 
> xennet0: rx no cluster
> Much of the time, these messages seem harmless, but occasionally, the network locks up on
> machines that display this message.
> 
> In looking at the source code, I get that this is a pool allocation failure in
> if_xennet_xenbus.c, but I don't understand which memory resource it's running out of and if
> there is a way to increase that resource.  In general, the domu's in question seem to have
> plenty of memory and I don't see a lot of memoory pressure for other tasks on the systems.
> 
> 	Has anyone else seen these messages on their domu machines and does anyone have ideas on
> how to correct the issue?

It's running out of mbuf clusters; this is the mclpl in vmstat -m

You can try increasing kern.mbuf.nmbclusters, or if that fail, rebuilding
a kernel with
options NMBCLUSTERS=xxxx
e.g.
options NMBCLUSTERS=65536

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