both processes showed up with the same size.

Yes, but which size? top shows a lot of information. If you don't know what the columns mean, your interpretation can be wildly wrong. Running the following very naive and simple program on my laptop (Linux PPC with a 2.4 kernel) and looking at top shows two processes of about 40 Mb apiece -- but the amount of shared memory for each process is exactly the same.

#!/usr/bin/perl

use strict;
use warnings;

my @foo;
$foo[10000000] = 1;

fork and sleep 10;
sleep 10;

[download]

As for the question of why Perl's ithreads are worse than forking, having seen the ithreads code only a couple of times and not being an expert on memory management by any means, I suspect Perl doesn't take advantage of the COW features of decent kernels. I make this guess because I don't know of any way that Perl could hint to the kernel to share specific memory pages.

In reply to Re^4: Handling multiple clients by chromatic
in thread Handling multiple clients by jalewis2

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.