Kalle, I just tried to bisect this and got an unexpected result: commit 4c3f49ae1306c05e91211c06feddfd0a4a57fabd "Merge branch 'for-5.1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu". I wanted to share this in case it is correct. I have a stronger suspicion that the problem has a race condition and appears intermittently, hence a peculiar bisect outcome. I will keep debugging. - Matthew Whitehead
