如何为包含250,000个文件的目录加速Perl的readdir？

I am using Perl readdir to get file listing, however, the directory contains more than 250,000 files and this results long time (longer than 4 minutes) to perform readdir and uses over 80MB of RAM. As this was intended to be a recurring job every 5 minutes, this lag time will not be acceptable. I am using Perl readdir to get file listing, ho