cRIO memory usage issues after LV upgrade

[andre.buurman@carya]

Hi,

I'm having available memory issues on code than ran fine on a cRIO-9014 using LV 2011.

After migration to LV 2018 I'm noticing strange behavior of the available memory.

I have the same code (using conditional disable structures) running as rtexe on 9014s and 9053s. Both system types display a gradual decline of available memory, where we didn't have that problem with 9014s running LV 2011.

The screenshot also displays another issue related to available memory, while top (Putty) shows about 393MB free memory the LV API shows 0kB, hence the very large free percentage (which is visible, divide by zero).

How can code that had no memory issues on 9014s running LV 2011 develop them with significant code changes (only changes required to have the same code run on 9014s and 9053s)? (LV 2018 is the only LV version both controller have in common).

 

SW install 9053:

SW install 9014:

Not directly available

[joerg.hampel · Accepted solution]

Hey Andre, there's some information out there regarding NI Linux RT and memory reporting:

• https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000000P9usSAC&l=en-US
• https://forums.ni.com/t5/LabVIEW/System-Resources-Memory-property-versus-shared-variable-NI/td-p/377...
• https://scoutapm.com/blog/determining-free-memory-on-linux 

Just in case you haven't found them yet. Maybe one of those links helps you narrow down the root cause.

J.

[andre.buurman@carya]

Hi Joerg,

Thanks for pointing me to these docs.

They shed light on the right resource to track actual memory usage of lvrt and that the LV API doesn't do a good job (better remove it than having something reporting wrong info 😉