Failed to create a tb6 file because 0 samples were collected

[Fabrizio_A_]

I'm trying this command:

mpirun -n 1 amplxe-cl -collect advanced-hotspots -result-dir DIR -- HELLO_WORLD

but the following error appears:

"Error: Failed to create a tb6 file because 0 samples were collected.".

What's wrong?

Thanks!

[David_A_Intel1]

how long does your app run?  if it is like most "hello, world" apps, it is not running long enough.

Another alternative is to specify a duration on the command line, add '-d 10', for example.

[Bernard]

Add some loop with a lot of floating point computation  presumably executed by calling library math functions. Hello world app will run too short for VTune to be able to sampling effectivaly. App must run longer than 2ms. 

[Bernard]

You may have a look at following video tutorial about the usage of VTune. Pay atrention to loop (matrix-matrix multiplication) in that video.

https://www.youtube.com/watch?v=HwR0_Sicorg&index=19&list=PLzwFYM4Q6gANPabEFlo8Ln0cipPfXzW3d

[David_A_Intel1]

Okay, my bad.  Adding the -d 10 doesn't help because, since VTune Amplifier is launching the app, it stops collection when the app terminates.

Try this command line: mpirun -n 1 amplxe-cl -c advanced-hotspots -r <your-results-dir> -d 10

This will collect system-wide for 10 seconds.  If that doesn't work, then you have a driver issue.  Please specify the OS.

Also, note, there are several sample application that are known to work included with the product.  See the <installed-dir>/samples/en directory.  However, I forgot this was MPI, so I'm not sure how useful they are for this situation.  Sorry. :\

[Fabrizio_A_]

Thanks everyone!

Mr.Anderson, I don't understand: you tell me 'adding -d 10 doesn't help', but in the command I have to try there is '-d 10'. What is the difference with the command I tried? 

I'm working with Centos 6.6 (virtual machine): are there any issues about virtual machine? As you can see from other my posts, I have some different errors testing simple programs. I'm able to collect only HOTSPOTS. 

Thanks again, I'm sorry!

[David_A_Intel1]

What I mean is, it doesn't help to add it to a command line where you are instructing VTune Amplifier to launch an application.  I want you to collect data for long enough to collect something meaningful.  Thus, replace the launching of the app, '-- HELLO_WORLD', with '-d 10' so that you collect data for 10 seconds.

[Fabrizio_A_]

And then, the launching of the app will be done in parallel, with another command line?

What about Centos virtual machine? Are there issues about it?

[David_A_Intel1]

No, I'm just trying to prove that the collector is working.  I still suspect your application is not doing enough work.  How long does HELLO_WORLD execute under normal conditions?

Virtual machines are not supported by the hardware-based collectors, e.g., advanced-hotspots, general-exploration, etc.  You are limited to the software-based collectors: basic-hotspots, concurrency, and locks-and-waits.

[Fabrizio_A_]

MrAnderson (Intel) wrote:

No, I'm just trying to prove that the collector is working.  I still suspect your application is not doing enough work.  How long does HELLO_WORLD execute under normal conditions?

Virtual machines are not supported by the hardware-based collectors, e.g., advanced-hotspots, general-exploration, etc.  You are limited to the software-based collectors: basic-hotspots, concurrency, and locks-and-waits.

Well, so probably the collector is not working because I'm on a virtual machine. BASIC HOTSPOTS works done with simple HELLO WORLD app. I can try on a cluster. I hope the problem is this.

Regards, and thanks for your patience.

[Bernard]

At least try to run printf or std::cout inside loop in order to generate enough workload for VTune sampling module.

[Bernard]

I bet that most of the time will be spent on User-to-Kernel mode transition and vice-versa. Of course additional workload like sending text or glyphs to display driver will be significant in your case.