Happy to hear it's working for you. I went asking for deeper answers, and this thread might interest you:

https://marc.info/?l=linux-rt-users&m=152906766629953&w=2
https://marc.info/?l=linux-rt-users&m=152907896201090&w=2

On Thu, Jun 14, 2018, 21:50 Paul Hedderly <paul@mjr.org> wrote:
On Wed, 2018-06-13 at 15:52 +0200, Jason A. Donenfeld wrote:
> Hi Paul,
>
> I got an -rt kernel up and running, enabled a bunch of nice debugging
> options, and found a handful of problems, all of which were fixed by:
> https://git.zx2c4.com/WireGuard/commit/?id=0f05452d043d8d047cf5d7987f
> c2732b97d676e6

Well just some feedback - I ran overnight on the -rt- kernel with no
wireguard... and it was clean and normal in the morning. Worked for a
couple of hours with and then fired up wireguard compiled from the
above commit - and its been running 10 hours now with no issues
whatsoever. dmesg nice and empty!

So many thanks - I think you nailed that one!

> I realize the solution in that patch is a bit of a bummer, but at the
> very least it keeps things from breaking now. I'll see if I can
> improve it somewhere down the line.

Its great to get a stable system again - brilliant work.

I love wg - and having it on android (user-space only because its a new
unrooted phone :( ) and Ubiquiti and LEDE... I'm sorted!

The GSOC projects are also very exciting prospects...