memory cgroups decreased the stability of 4.8, regardless of whether they were actively being used; we were not actively using them, but still experienced lockups. Disabling them on the kernel command line fixed it.
I'm not sure if it's been fixed in 4.9 because I removed memcgroups them from our kernel compilation entirely. It'd certainly be worth trying 4.9.18 if you haven't already, as I know they were working on the problem. -- Laurence "GreenReaper" Parry - Inkbunny administrator greenreaper.co.uk - wikifur.com - flayrah.com - inkbunny.net "Eternity lies ahead of us, and behind. Have you drunk your fill?"
