I updated from linux-image-amd64 version 6.12.113-1 to 6.12.115-2
yesterday evening. Today as soon as users started using the system with
some load, the network completely becomes unresponsive. tcpdump only
shows outgoing ARP responses and nothing else. When booting the system
with iommu=pt, the netwok continues to work even with load.
This sounds a lot like bug #1149564
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1149564
but this one was supposed to be fixed in 6.12.113. Has this regressed
again?
I attached a kernel log of a session without iommu=pt where it just hangs.
I have not seen this problem on this system with
6.12.111, nor 6.12.113 on this system (Dell PowerEdge R7425, AMD CPUs),
although it might theoretically be possible that not enough load was
caused to trigger this issue. It seems unlikely though, seeing how it
now happens after a few minutes.