Resolved: Was: PROBLEM: NETDEV WATCHDOG r8169 transmit queue time out in commit 4fd48c4ac0a0578862819295222a825c97686ac7 onwards.

Not sure if this was picked up when I originally posted it, or if this feedback is useful but:

I noticed some rtl8169 driver changes in 4.18.15, pulled that from git last friday and rolled it and did some bandwith intensive rsync tests etc that would provoke the problem quite reliably before, and got no reaction.

Gentoo released the gentoo-sources for 4.18.16 on Sunday and I switched back to using this kernel, and this has been stable for 3 days now, versus the problem traditionally turning up within 2-12 hours, again suggesting the problem has gone away (or at least significantly changed).

Just to confirm that this seems to have fixed things for me, and to thank you for all the time and effort (both on the relevant module and more generally).

Iain