I wrote two different codes doing the same thing. In the older version, I only declared some variables but no arrays in modules. I used openmp to parallelize it. In this case, the code works well and is successfully accelerated. However, the new version code cannot be accelerated. In this version, I declared some allocatable arrays, which are only assigned before I run any parallelized codes, in modules. In the new version, the performance is lower then the single thread case after parallelized. Should I avoid to use allocatable arrays in module? Or, there are some thing should be set such as environment variables.
