Difference between revisions of "OpenMP in Small Bites/Worksharing"

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OpenMP in Small Bites/Worksharing
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|title = What is most commenly used worksharing construct in OpenMP to distribute work among loop interations?
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|title = 1. What is most commenly used worksharing construct in OpenMP to distribute work among loop interations?
 
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|title = Give an example for a parallel vector addition using OpenMP worksharing!
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|| Fork-Join: C/C++:<br /> <code>int i; <br /> #pragma omp parallel <br /> #pragma omp for <br /> for (i = 0; i < 100; i++){ <br /> a[i] = b[i] + c[i]; <br /> } </code> <br /> Fortran: <br /> <code> INTEGER :: i <br />!$omp parallel <br />!$omp do <br /> DO i = 0, 99<br /> a[i] = b[i] + c[i] <br /> END DO </code>
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|| C/C++:<br /> <code>int i; <br /> #pragma omp parallel <br /> #pragma omp for <br /> for (i = 0; i < 100; i++){ <br /> a[i] = b[i] + c[i]; <br /> } </code> <br /> Fortran: <br /> <code> INTEGER :: i <br />!$omp parallel <br />!$omp do <br /> DO i = 0, 99<br /> a[i] = b[i] + c[i] <br /> END DO </code>
 
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    Give an example for a parallel vector addition using OpenMP worksharing!
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    (C/C++:
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|title = 3. Can the following code snipped be parallelized with the OpenMP for-construct with out breaking the semantic? Justify your answer.
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|| <code> int i, int s = 0; <br /> for (i = 1; i < 100; i++){ <br />  s = a[i-1] + a[i]; <br /> }  </code> <br /> No. Due to the depency between the loop iterations this would cause a data race
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Revision as of 18:34, 30 October 2020



HPC.NRW
HPC.NRW
Other HPC Courses
1. Gprof Tutorial
2. Introduction to Linux in HPC
OpenMP in Small Bites
1. Overview
2. Worksharing
3. Data Scoping
4. Non-Uniform Memory Access







Video


Quiz

1. What is most commenly used worksharing construct in OpenMP to distribute work among loop interations?

Click and submit to see the answer

2. Give an example for a parallel vector addition using OpenMP worksharing!

Click and submit to see the answer


3. Can the following code snipped be parallelized with the OpenMP for-construct with out breaking the semantic? Justify your answer.

Click and submit to see the answer










How can you control the number of threads?

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