<div dir="ltr"><div><div><div><div>HI<br><br></div>I am new in Open MP and willing to learn . I am reading the Open MP documentation and this tutorial <br><br><a href="https://computing.llnl.gov/tutorials/openMP/exercise.html" target="_blank">https://computing.llnl.gov/tutorials/openMP/exercise.html</a><br><br>I
am really new to parallel programming , I have been searching over
diferent examples and at the end I am trying to create a simple loop
faster in omp than without, here is my code: <br><br> #include <omp.h> <br> #include <stdio.h> <br> #define N 100000 <br> <br> main () <br> { <br> <br> int i; <br> float a[N], b[N], c[N]; <br> <br> /* Some initializations */ <br> for (i=0; i < N; i++) <br> a[i] = b[i] = i * 1.0; <br> <br> double start = omp_get_wtime(); <br> <br> omp_set_dynamic(0); <br> omp_set_num_threads(4); <br> <br> #pragma omp parallel shared(a,b,c) private(i) <br> { <br> <br> #pragma omp for schedule(static) <br> for (i=0; i < N; i++) <br> c[i] = a[i] + b[i]; <br> <br> } /* end of parallel section */ <br> <br> double end = omp_get_wtime(); <br> <br> printf("%f\n",start); <br> printf("%f\n",end); <br> printf("%f\n",end - start); <br> <br> } <br><br></div>Same
code but with out the #pragma sections , the problem is that is not
always faster than serial code, some times serial code is even faster . <br><br></div>Any
clue is more than welcome, if this is not he mailing list to post this
please tell me. I am really interested to lear Open MP <br><br></div>Thanks a lot and regards<div class=""><div id=":1k4" class="" tabindex="0"><img class="" src="https://ssl.gstatic.com/ui/v1/icons/mail/images/cleardot.gif"></div></div></div>