Why are you running as many children in parallel as you have rows? For 1000 rows, you will launch 1000 children in parallel.

The idea of Parallel::Forkmanager is to use the optimal number of parallel children, which is usually roughly the number of CPUs (or cores) of your machine, and not the number of tasks to be processed.

Other people have already recommended a smaller number of concurrent processes, like 4 or 8. Maybe you should try that suggestion.

In reply to Re^3: Fork vs pThreads by Corion
in thread Fork vs pThreads by ThelmaJay

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