title: OpenMP parallel for region thread affinity
body: <p>Let's say I have the following OpenMP region:</p>
  
  <pre><code>omp_set_num_threads(3);
  #pragma omp parallel for
  {
   //start
   ...
   //somewhere in the middle
   ...
   //end
  }
  </code></pre>
  
  <p>Let's say I have 8-core system. For example, after "start" let's say thread 0 is running on core 4, thread 1 runs on core 5, and thread 2 runs on core 6. Is it possible "somewhere in the middle" before the "end" that threads migrate from their respective cores that they were assigned after "start"? I.e. is it possible that threads 0-2 are assigned to cores 4-5 after "start", and "somewhere in the middle" threads say migrate to cores 5-7, respectively? And will even be possible that threads may reside just before the "end" on cores 0-2? Thanks.</p>