Some ground work:

The code:
sleep;
Takes roughly 1.5 megs, as reported by taskmanger in windows.

The code:
my $x = "a" x 5_000_000; sleep;
Takes roughly 11.2 megs, again as reported by taskmanager.

The code:
my $x = "a" x 5_000_000; my $y = $x; sleep;
Takes roughly 16.1 megs.

Can anyone explain why it seems to take half as much memory to duplicate it? I could see either requiring twice as much memory to realllocate the entire string again, or only requiring a miniscule amount to just store a pointer to the original data, but half?

In reply to Possibly silly perl memory allocation question, duplicating scalars by BUU

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