vtune problem

vtune problem

rohit t.'s picture

hi !

plz help me out with this issue.!when i ran a very simple C++ program for hotspot analysis.it succesfully collected ,analysed and finalized the result

still sometimes its shows functions with some CPU values and sometimes show " NO DATA TO SHOW / NO DATA IS AVAILABLE".

please tell me how to  get the data when this "NO DATA IS AVAILABLE" situation arises.

 

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Peter Wang (Intel)'s picture

 Usually if you ran application shortly, there is no result to how. Please add more workloads in your program.

Peter Wang (Intel)'s picture

 Usually if you ran application shortly, there is no result to how. Please add more workloads in your program.

rohit t.'s picture

thanks for suggestion.I ll try this way also

rohit t.'s picture

thanks for suggestion.I ll try this way also

iliyapolak's picture

Maybe your application run so fast(short period of time) and was below the measurement threshold.I experienced such a behaviour.

Peter Wang (Intel)'s picture

Quote:

iliyapolak wrote:

Maybe your application run so fast(short period of time) and was below the measurement threshold.I experienced such a behaviour.

Default interval time is 10ms. You might copy from Hotspots analysis to create a new custom analysis - change interval value to 2ms if you like.

iliyapolak's picture

>>>Default interval time is 10ms. You might copy from Hotspots analysis to create a new custom analysis - change interval value to 2ms if you like>>>

Thanks Peter.

Can I change time measurement interval to even lower value for example in range 0.1-0.2 msec , because I'm testing a FFT alghorithm which finishes execution of its code very quickly ~125000 nanosec?In order to perform precise timing I needed to increase data set size to more than 4096 points.

Peter Wang (Intel)'s picture

Quote:

iliyapolak wrote:

>>>Default interval time is 10ms. You might copy from Hotspots analysis to create a new custom analysis - change interval value to 2ms if you like>>>

Thanks Peter.

Can I change time measurement interval to even lower value for example in range 0.1-0.2 msec , because I'm testing a FFT alghorithm which finishes execution of its code very quickly ~125000 nanosec?In order to perform precise timing I needed to increase data set size to more than 4096 points.

No. 2ms is minimal value for interval, I recommend.

rohit t.'s picture

thanks peter !

error resolved ! reducing the time -interval to 2ms did work !

iliyapolak's picture

>>>No. 2ms is minimal value for interval, I recommend.>>>

Thank you Peter.

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