Touch Dreams

The coming International Workshop on OpenMP (IWOMP 2006) has a paper titled “Common Mistakes in OpenMP and How to Avoid Them” written by Michael Süß and Claudia Leopold (University of Kassel, Germany).

The result is based on a survey of two undergraduate courses. The authors of the paper kindly allow me to list the 15 common mistakes presented in their paper here,

1. (Correctness) Access to shared variables not protected
2. (Correctness) Use of locks without flush
3. (Correctness) Read of shared variable without flush
4. (Correctness) Forget to mark private variables as such
5. (Correctness) Use of ordered clause without ordered construct
6. (Correctness) Declare loop variable in #pragma omp parallel for as shared
7. (Correctness) Forget to put down for in #pragma omp parallel for
8. (Correctness) Try to change num. of thr. in parallel reg. after start of reg.
9. (Correctness) omp_unset_lock() called from non-owner thread
10. (Correctness) Attempt to change loop variable while in #pragma omp for
11. (Performance) Use of critical when atomic would be sufficient
12. (Performance) Put too much work inside critical region
13. (Performance) Use of orphaned construct outside parallel region
14. (Performance) Use of unnecessary flush
15. (Performance) Use of unnecessary critical

For detail, please read the full paper.