Created attachment 227361 [details] dmesg No adverse effects are noticed but this must be from quite a recent commit. I don't know if a bisect is warranted so I will just attach .config and dmesg for now.
Created attachment 227371 [details] kernel .config
Try a newer mainline kernel and see if the problem has already been fixed.
4.8 made it to stable and the issue is gone. I think it was a preemption developer warning anyway. I'll close as fixed.