Most ops have a target, an invisible lexical that stores their result. "a" x 5_000_000 is initially stored in this target (bound to that x operation), then assigned (copied) into $x. For some operations of form $lexical = expr1 op expr2 the op target is diverted onto $lexical and the assignment is optimized away, but the repeat (x) op isn't one of those; don't know why.

Targets stay allocated for as long as their code is around (in the theory that next time the op is used, space for its result needn't be allocated again); the only easy way to reclaim their memory is to remove all references to the code they are in.

In reply to Re: Possibly silly perl memory allocation question, duplicating scalars by ysth
in thread Possibly silly perl memory allocation question, duplicating scalars by BUU

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.