Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Ubuntu 12.04 LTS (fresh install with all updates) Nvidia 8400GS Galaxy (instead of the on-board video) Dell

I'm having random freezes where everything locks up, no mouse/keyboard/etc. Upon running Memtest86+, I get a "Unexpected Interrupt - Halting" error. I disconnected everything except for the keyboard/mouse/monitor/added video card when I ran the test.

I've searched everywhere for what this means, but I only seem to find where people have the same error, but with a CPU0 at the end (e.g., "Unexpected Interrupt - Halting CPU0").

Does anyone have any idea what the error message means when there's just the "Unexpected Interrupt - Halting" error?

I'm starting to test the memory modules one-by-one, but it would be nice to know if there's potentially something else going on.

Learning a lot and really enjoying the OS (when the computer doesn't crash :-) ).

share|improve this question
From the source code of the memtest86 program it looks like the next line contains the type of interrupt. What does the "Type" line say? – John S Gruber Jul 31 '12 at 3:56

From the source to memtest86+ I can see that the version (4.20-1.1ubuntu1) in Precise handles parity errors explicitly. (PARITY_MEM is defined in config.h to enable separate handling of vector ==2).

So the error you are getting is not for a memory parity error.

As a guess I would suggest that the memory test is triggering some memory-mapped I/O in your system, causing an interrupt as an accidental byproduct. This doesn't necessarily suggest a problem.

Knowing the kind of interrupt from the next line of the error screen might help someone to narrow this down.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.