Ok, but during these messages (sometimes many) [152.197966] NMI watchdog: BUG: soft lockup - CPU # 3 stuck for 22s! [swapper / 3: 0] the system stops responding, only to end up completely blocked. It will not always be a full-blown panic, but there is a systematic defect, since up to 3.16.6 worked perfectly. What if you could have the kernel of Tumbleweed before September 8, I could give you a good indication on where the error was introduced.