I've noticed that one of the cores on a four-core laptop is pegged, and the temp is very high. I found this in top:  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND  359 root      20   0  188684 147228   1552 R  99.4  5.0 111:19.91 systemd-udevd20011 root      20   0  188320 147604   2076 S  11.0  5.0   0:00.33 systemd-udevd11053 dotanco+  20   0 3030036 918672  49608 S   9.6 31.2 280:40.65 firefox 3468 dotanco+  20   0 3612776 136740  43484 S   1.7  4.6  57:02.52 plasma-desktop20006 root      20   0       0      0      0 Z   1.0  0.0   0:00.37 systemd-udevdWhy might systemd-udev be hammering the CPU? This is a Kubuntu 14.10 system:$ uname -aLinux loathe 3.16.0-44-generic #59-Ubuntu SMP Tue Jul 7 02:07:39 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux$ cat /etc/issueUbuntu 14.10 \n \lEDIT: I notice that in addition to the pegged CPU, there is an additional problem. Newly connected USB devices, such as a USB mass storage device or keyboard, will show up in lsusb but are unusable. The mass storage device is not auto mounted, and the USB keyboard does not work. I have not tried to manually mount the USB drive.As per Bratchley's suggestion, here is the strace of the systemd-udev process with ID 359.
Why is systemd-udev pegging my CPU?
systemd;cpu usage