Whilst it doesn't cause a core dump, another method for bailing out of perl quickly, is to use the POSIX module..

use POSIX qw(_exit);

POSIX::_exit( 0 ); # abort ungracefully (and quickly!)
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When perl dies it usually appears to spend lots of time closing file handles. For a forked server that has lots of sockets open this could take some time, so why not let the OS deal with the messy issues and use POSIX::_exit().