A loop starting at line 23 was vectorized. A loop starting at line 35 was vectorized. A loop starting at line 35 was tasked. Since the ARSC J90 system is shared by many users, and some timers report only the total CPU times, a user might observe is an increase in the total CPU time. This is checked by comparing the totals with the count from the hardware performance monitor, hpm.
Care is needed in choosing a suitable time basis and interpreting results.
The aim is to use parallelism to reduce the overall wall-clock time. As you can see, the simple example code below gives a very high level of parallel performance since it is perfectly parallel. Real codes will be more likely to decline rapidly and atexpert allow users to investigate the parallel performance of each subroutine so poorly performing areas of code can be improved. One advantage of multiprocessor shared memory systems is that a performance improvement can be obtained by parallelizing only the computationally intensive parts of the code. While there is much debate on the need to ensure that a single code doesn't hog the entire memory while only using one processor, partial parallelization can be beneficial to both the user running in parallel and other users who gain access to resources sooner.