High CPU usage when matlab is idle on Linux

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Hi all, I installed Matlab (R2012a) on a core i5 machine with 4 GiB of RAM. The OS is Ubuntu 11.04 64 bit. Matlab works fine, (apart from some Unix version related issues), but when idle it takes more than 100% CPU. The top command reports:
17162 newcesir 20 0 1137m 382m 70m S 107 4.8 2:35.14 MATLAB
9 root 20 0 0 0 0 S 21 0.0 898:12.00 ksoftirqd/1
3 root 20 0 0 0 0 S 19 0.0 923:00.86 ksoftirqd/0
13 root 20 0 0 0 0 S 10 0.0 779:41.32 ksoftirqd/2
16 root 20 0 0 0 0 S 0 0.0 640:55.65 ksoftirqd/3
The 4 ksoftirqd processes have something to do with interrupt handling for the 4 processors, and are assciated with the matlab running. The machine is multi user, and having one cpu occupied for every matlab instance started is not good at all. Does anyone know why this is happening? Thank you
Walter Roberson
Walter Roberson on 20 Jul 2012
Different startup scripts?
Also, I would suggest deleting the MATLAB preferences file and re-creating it.

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Accepted Answer

Adam Filion
Adam Filion on 20 Jul 2012
Edited: Adam Filion on 20 Jul 2012
Have you rebooted your Linux machine since July 1? If not then that may be the problem. There was a bug with Linux that caused all kinds of problems with the leap second on July 1:
This bug has caused some strange behavior for various programs, MATLAB included. Rebooting the machine fixes the problem. If that doesn't resolve it then I recommend contacting tech support:
[EDIT fixed links]

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