If it helps, I've been seeing the same thing here on a system with an
r8169.  The message appears consistently enough on network startup to
be able to track it down to this specific commit:
    98ddf986fca17840e46e070354b7e2cd2169da15: r8169: bh locking redux
and task scheduling.

The softirq pending messages always come right after "link down"
messages for the interface.

Marc