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SubVI overhead


Hi, I am not certain that I fully understand the concept called ' Sub VI overhead'. I need to know more about this 'overhead' to learn more. Help me!

Best Regards,
Dhans 😉
Kudos are welcome 😉
Aspirant Labview Programmer (Labview 14) 😉
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Message 1 of 10
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Hi dhans,

 

did you read the LabVIEW help?

Best regards,
GerdW


using LV2016/2019/2021 on Win10/11+cRIO, TestStand2016/2019
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Message 2 of 10
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Hi GerdW,

    I did. But I cannot understand the term 'overhead'. Glad to have conversation with you again.!!

Best Regards,
Dhans 😉
Kudos are welcome 😉
Aspirant Labview Programmer (Labview 14) 😉
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Message 3 of 10
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Hi dhans,

 

I cannot understand the term 'overhead'

"overhead" in Wikipedia

Best regards,
GerdW


using LV2016/2019/2021 on Win10/11+cRIO, TestStand2016/2019
Message 4 of 10
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Hi GerdW,

  According to the link you pasted, Can I take that term ' Overhead' as Excessive execution time for sub VI than Calling VI?

Best Regards,
Dhans 😉
Kudos are welcome 😉
Aspirant Labview Programmer (Labview 14) 😉
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Message 5 of 10
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Hi dhans,

 

yes, LabVIEW (might) needs to handle memory allocations, parameter forwarding, etc. when calling a subVI - as is mentioned in the LabVIEW help.

You can reduce this overhead by the menthods also mentioned in the LabVIEW help…

Best regards,
GerdW


using LV2016/2019/2021 on Win10/11+cRIO, TestStand2016/2019
Message 6 of 10
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Hi, GerdW

Yes. I did read all of them. Now only clearly understand! Thank you!!!

Best Regards,
Dhans 😉
Kudos are welcome 😉
Aspirant Labview Programmer (Labview 14) 😉
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Message 7 of 10
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Worth noting is that this overhead is usually negligable. Only in very tight loops is it worth using Inline function to gain that last 0,01% performance.

 

Did you ask for a specific program issue or just for knowledge?

/Y

G# - Award winning reference based OOP for LV, for free! - Qestit VIPM GitHub

Qestit Systems
Certified-LabVIEW-Developer
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Message 8 of 10
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Hi, Yamaeda,

Just for knowledge. I haven't encountered any situation but knowing these things will help me in future. That's why.

Best Regards,
Dhans 😉
Kudos are welcome 😉
Aspirant Labview Programmer (Labview 14) 😉
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Message 9 of 10
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I agree with the others.  The majority of our reuse library is inlined because it is code that is usually called often, and is code we don't expect to debug or edit (debugging has to be off for inlining).  And automatic error handlers shouldn't be happening for small reuse functions either, they should just return the error and have the calling code handle it.

 

That being said I've never seen an issue with performance, where inlining a VI was the solution.  It might help, but probably not enough to matter.

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Message 10 of 10
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