I don't believe you - if you have use strict; use warnings when you also have:

my $total_size = total_size(\%val);
print "\%val :",$total_size,$/;
my $total_size = total_size(\%seen_cdr);
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Your code is generating errors: "my" variable $total_size masks earlier declaration in same scope.

Either you don't have these switched on, or you've code that's generating errors every time it runs, and you're asking for someone to fix it for you.