Please read Markup in the Monastery and update the formatting of your node. Right now it's not readable.

As for parallelization, if the processing of files is independent of each other, just start a new process for each file. See for example Parallel::ForkManager.

Or you can use a completely external solution. For example on linux, xargs can parallelize for you:

ls *.csv | xargs -P 8 -n 1 perl yourscript.pl {} \;
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I'd also recommend to profile your code to identify bottlenecks.