I asked one of the SUSE systemd/udev maintainers and he confirmed it: Since SLE12, devtmpfs pseudo filesystem is used. Therefore the kernel creates the device nodes and udev is simply running the rules to set, amongst others, device permissions. I told him that one same code in "rear"...
At that time kthreadd that was responsible for creating workers was busy isolating the pages for the zone compaction. Raw [1140818.459880] CPU: 5 PID: 813 Comm: systemd-udevd Kdump: loaded Tainted: P OE --- 3.10.0-1160.36.2.el7.x86_64 #1 [1140818.459881] Hardware name: VMware, Inc. VMw...