A warning message during SRIOV multicast cleanup should have actually been
a debug level message. The condition generating the warning does no harm
and can fill the message log.
In some cases, during testing, some tests were so intense as to swamp the
message log with these warning messages, causing a stall in the console
message log output task. This stall caused an NMI to be sent to all CPUs
(so that they all dumped their stacks into the message log).
Aside from the message flood causing an NMI, the tests all passed.
Once the message flood which caused the NMI is removed (by reducing the
warning message to debug level), the NMI no longer occurs.
Sample message log (console log) output illustrating the flood and
resultant NMI (snippets with comments and modified with ... instead
of hex digits, to satisfy checkpatch.pl):