title: How to tell if OpenMP is working?
body: <p>I am trying to run LIBSVM in parallel mode, however my question is in OpenMP in general. According to <a href="http://www.csie.ntu.edu.tw/~cjlin/libsvm/faq.html#f432">LIBSVM FAQ</a>, I have modified the code with #pragma calls to use OpenMP. I also modified the Makefile (for un*x) by adding a -fopenmp argument so it becomes:</p>
  
  <pre><code>CFLAGS = -Wall -Wconversion -O3 -fPIC -fopenmp
  </code></pre>
  
  <p>The code compiles well. I check (since it's not my PC) whether OpenMP is installed by :</p>
  
  <pre><code>/sbin/ldconfig -p | grep gomp
  </code></pre>
  
  <p>and see that it is -probably- installed:</p>
  
  <pre><code> libgomp.so.1 (libc6,x86-64) =&gt; /usr/lib64/libgomp.so.1
   libgomp.so.1 (libc6) =&gt; /usr/lib/libgomp.so.1
  </code></pre>
  
  <p>Now; when I run the program, I don't see any speed improvements. Also when I check with "top" the process is using at most %100 CPU (there are 8 cores), also there is not a CPU bottleneck (only one more user with %100 CPU usage), I was expecting to see more than %100 (or a different indicator) that process is using multiple cores.</p>
  
  <p>Is there a way to check that it is working multiple core?</p>