Matlab sometimes stuck at 'busy' for very simple computing. Force stop (ctrl+v) won't work.

Matlab sometimes stuck at 'busy' for very simple computing. Like merging two 1-column matrix by c = [a,b]. (only 10k rows).

Computer specs is way beyond enough for performing this task (64 core 128 thread with 512GB RAM).

Force stop (ctrl+v) won't shut down for a long time. But when it finally works, and I just copy paste the command again, it will finish in 1 sec.

While stuck, Matlab uses 8% of the CPU power, with half the thread running at 20%. I'm wondering what is causing this and how I can avoid this from happening.

[Erik Lekholm]

I have the same problem, and it started lately and suddenly - possibly after I upgraded to R2022a (upgrated to Big Sur about the same time, so not sure...).

It's not code-specific. I note that when rerunning a section again without altering the code, there is no delay. However, if even single character is changed in the code (even if deleted again), there is sometimes a long delay when executing the same section again. This makes me think the problem relates to syntax checking in the editor.

[Walter Roberson]

Is it possible that a network drive is involved? For example one of the directories on the path (or current directory) happening to live on OneDrive?

Answer 1

[Simar]

Hi Andi,

I understand that you are experiencing performance issues with MATLAB where it becomes stuck on the 'busy' status during simple computation.

The issue might be related to MATLAB's integrated development environment (IDE) rather than the actual computation of merging two vectors. Here are some potential causes and workarounds for the problem:

1. Java Heap Memory: MATLAB's IDE uses Java, and if the Java heap space is insufficient, it could cause performance issues.

Workaround: Try increasing the Java heap space. Go to MATLAB preferences (Home > Preferences > MATLAB > General > Java Heap Memory) and adjust the slider to allocate more memory.

2. Background Services or Processes: MATLAB may be running background services or processes that are not apparent but could be affecting performance.

Workaround: Restart MATLAB to see if the issue persists. If it does, consider restarting computer to terminate any background processes that might be interfering with MATLAB's performance.

3. File System Access: Delays can occur if MATLAB is trying to access files on network drives or synchronized folders (like Dropbox or Google Drive).

Workaround: Ensure that the files are stored locally on computer and that the MATLAB current folder is set to a local directory.

4. MATLAB Preferences or Settings: Sometimes, corrupted MATLAB preferences or settings can cause unusual behaviour.

Workaround: Reset MATLAB preferences by renaming the preferences directory. One can find the preferences directory by typing “prefdir” in the MATLAB Command Window. Close MATLAB, rename the directory, and restart MATLAB to regenerate the preferences.

If it persists, contact MathWorks support for assistance. Remember to back up any important scripts or data before making significant changes to MATLAB installation or preferences.

Please refer to the following documentation link-

https://in.mathworks.com/help/matlab/ref/prefdir.html?searchHighlight=prefdir&s_tid=srchtitle_support_results_1_prefdir

Hope it helps!

Best Regards,  

Simar