Machine Check Exception:
A Machine Check Exception (MCE) is a type of computer hardware
error that occurs when a computer's central processing unit detects a
hardware problem.
Your computer experienced a hardware error and the kernel logged an event in a buffer. You can use mcelog
to log and view the machine check events. From mcelog
manpage:
X86 CPUs report errors detected by the CPU as machine check events
(MCEs). These can be data corruption detected in the CPU caches, in
main memory by an integrated memory controller, data transfer errors
on the front side bus or CPU interconnect or other internal errors.
Possible causes can be cosmic radiation, instable power supplies,
cooling problems, broken hardware, running systems out of
specification, or bad luck.
Most errors can be corrected by the CPU by internal error correction
mechanisms. Uncorrected errors cause machine check exceptions which
may kill processes or panic the machine. A small number of corrected
errors is usually not a cause for worry, but a large number can
indicate future failure.
When a corrected or recovered error happens the x86 kernel writes a
record describing the MCE into a internal ring buffer available
through the /dev/mcelog device. mcelog retrieves errors from
/dev/mcelog, decodes them into a human readable format and prints them
on the standard output or optionally into the system log.
If you didn't notice any crash, probably the error was successfully corrected. Still, I advise you to install mcelog
to keep track of such events:
sudo apt-get install mcelog
The events will be logged to /var/log/mcelog
. You can also run:
sudo mcelog --client
to query the mcelog
daemon for errors.