VI Front Panel in SubPanel reacts slowly

[dbaechtel]

In LabView 2010F2, I have a VI that has several buttons and other controls on the Front Panel. When I run that VI standalone, it runs very quickly, uses less than 20% CPU, and is very responsive. ALl of the controls react very quickly. But when I put that same VI FP in a subpanel in a small VI, all of the controls in the VI in the subpanel are now running very slowly. There buttons are slow to react. There is almost a 1/2 second delay on the buttons. The CPU is stall down around 25% usage. The hosting VI does not do much and should not be responsible for this delay.

If the CPU is not very busy, what is the cause for the delay in the reaction of a Front Panel of a VI that is placed in a subpanel?

What can be done to significantly improve the response of a FP that is placed in a subpanel?

[esmaham]

Hi dbaechtel,

Do you see the same behavior in older versions of LabVIEW ?

Thanks and have a great day.

[dbaechtel]

I haven't used any of the previous versions of LabView, so I don't know how they compare in this.

[Ben]

How is you memory doing?

Do you have "show Kernal time' selected?

Ben

[dbaechtel]

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@Ben wrote:

How is you memory doing?

Do you have "show Kernal time' selected?

Ben

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Where would I find that selction?

[Ben]

Windows Taks Manager >>> View >>> Show Kernal Times

[dbaechtel]

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@Ben wrote:

How is you memory doing?

Do you have "show Kernal time' selected?

Ben

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CPU Usage and Kernel Time do not pudge much during Save All or Clean Up Diagram of large diagram.  CPU usage stays about 25%, Kernel time stays about 50-75% of Total CPU Usage.

I don't see any reason why LV would show "not responding" under these conditions unless there are some long LV processes that are being executed that include significant I/O delays that do not relinquish the CPU to do other things while executing these long LV processes. If LV was not blocked by I/O (disk) delays then I should see near 100% CPU usage. If LV was being delayed by memory swapping, the I should see less than 50% memory free,

[Ben]

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@dbaechtel wrote:

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@Ben wrote:

How is you memory doing?

Do you have "show Kernal time' selected?

Ben

---

CPU Usage and Kernel Time do not pudge much during Save All or Clean Up Diagram of large diagram.  CPU usage stays about 25%, Kernel time stays about 50-75% of Total CPU Usage.

I don't see any reason why LV would show "not responding" under these conditions unless there are some long LV processes that are being executed that include significant I/O delays that do not relinquish the CPU to do other things while executing these long LV processes. If LV was not blocked by I/O (disk) delays then I should see near 100% CPU usage. If LV was being delayed by memory swapping, the I should see less than 50% memory free,

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I'll leave the discusion of Internals and Data Structure for another thread.

Spoiler

Both of my copies of that book are much more worn.

It is going to take some work to narrow down the possiblitlites since you have presented this situation as an interaction problem.

Generally speaking there is one hot button that comes to mind and that is the UI (User Inteface) thread where all GUI updates are handled as well as those things that do not play well if left to run in their own threads (property nodes for example).

SO I would like to suggest you start by trimming it down to something that work good and then start adding stuff back until you can detect the performance hit. At tath point step back and look for contention issues.

If I remebe correctly you can't post code images so asking you to post images of teh code that does not play nice together is a no-go.

You could also run the performance monitor.

THe Trace Execution tool kit should aslo help you get a the root of this situation.

Trying to help, wondering if if I can,

Ben

PS Regarding the bug thread. I depend on that thread to stay on top of potential bugs. I asked and Laura moved the off-topic posts to the proper thread. Please excuse my "anal-retentive" side.

[Intaris]

Apologies for the thread necro:

We are currently seeing this issue also. We have 24 individual VIs which we swap into and outof sub-panels (8 in total).  When used on their own, response is snappy but in a sub-panel, things get really slow.  We observe an appreciable delay when trying to do anything on the sub-VI in the sub-panel.

I'd be interested to hear if anyone else has observed / solved this problem.

FWIW, we have an XControl on the FP of the sub.VIs.

[Norbert_B]

Did you try to get more detailed info using DETT?

Norbert