Thank you for all the replies.
(Btw, I am the same Thushan. I don't have access to my other profile as I created it yesterday using my office email.)

Apologies for if I was not clear enough in my original post. But most people clearly saw the problem.

But obviously some did not see the problem.

It's clear that the above snipet is not some production code. It was written to show the bug. So, don't look at the wrong place and call it silly code. :)

For those who want to test:
First run the second code snipet and observe your system memory. You'll see no increased usage in it. Then run the first code snipet and do the same observation. You'll see that memory usage gradually increases over time (for the Perl process). That should not be the case. Read goto &sub_name syntax documentation.
I'll report a bug for this as suggested by Joost.
Thank you