The Anonymous Monk post in 11157181 made me wonder if the the memory usage pattern changed with perl versions.

Running against the most recent releases of Strawberry Perl for each major version, the memory usage is low for perls prior to 5.20. From 5.20 (tested with 5.20.3) it shows the large usage pattern.

5.20 is when COW was first on by default. https://metacpan.org/release/RJBS/perl-5.20.0/view/pod/perldelta.pod#Performance-Enhancements

FWIW, the in-memory loop runs faster than the file-read loop for Strawberry Perls 5.16 and 5.18, and then becomes slower after 5.20. The difference is just not so large on non-MSYS2 and Cygwin perls.

In reply to Re^5: RE on lines read from in-memory scalar is very slow by swl
in thread RE on lines read from in-memory scalar is very slow by Danny

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.