title: Nest a parallel for-loop inside a parallel for-loop
body: <p>I want to do this:</p>
  
  <pre><code>omp_set_nested(1);
  #pragma omp parallel for private(j)
  for (i = 0; i &lt; n; ++i) {
      #pragma omp parallel for
      for (j = 0; j &lt; m; ++j) {
      /* do smth */
      }
  }
  </code></pre>
  
  <p>It means, if I have 8 threads, and first loop uses only 4 threads, I want internal loop to use other 4 threads too. How can I do this?</p>