I have only been able to reproduce this on our production workloads, and we've recently downgraded from HWE (4.8.0-X) to GA (4.4.0-66), where we currently aren't seeing any issues.
If I see the issue reappear, I'll try to verify it with a mainline kernel, if someone finds a way to reproduce this consistently, I'll happily help bisect this.
I have only been able to reproduce this on our production workloads, and we've recently downgraded from HWE (4.8.0-X) to GA (4.4.0-66), where we currently aren't seeing any issues.
If I see the issue reappear, I'll try to verify it with a mainline kernel, if someone finds a way to reproduce this consistently, I'll happily help bisect this.