Where do the values from NI Distributed System Manager come from?

[Thomas444]

Hello, 

I am using cRIO 9065 and I have this problem with memory leaks. I need to see and log the available memory over time. I used System Session > FreePhysMem, which returns the same values as command "top" in Linux. This on the other hand shows very different results than NI Distributed Systems Manager. Linux shows about 30 MB of available memory less and peaks to 5 MB (!) of available memory during certain stages of operation, whereas Manager memory is way more constant over time and actually doesn't peak that low. My hypothesis is that Labview allocates more memory than necessary and Manager counts with that, on the other hand Linux shows actual real free memory. 

Also during slow memory leak that I'm experiencing, Linux starts showing these 5MB peaks few minutes after startup, but Manager free memory slowly diminishes and after 20 hours or so it gets to 0 and cRIO crashes.

My question is where does the Manager gets these values and how can I obtain it inside LabVIEW.

Thank you.

[wiebe@CARYA]

If 'top' returns what you want you can probably use the System Exec to call 'top' (or 'htop').

[MichaelBalzer · Accepted solution]

This knowledge base article touches on the differences between Linux memory reporting and DSM memory reporting. The code example provided shows the proper way to query your application's memory usage under Linux RT, and how to monitor the memory usage from within your LabVIEW application.