I have used this one time and it seemed to work pretty well. Here's how I did it (but I'm sure there are many other/better ways)

use strict;
use Time::HiRes qw ( gettimeofday );
...[some code]
my $start = 0;
...[some code]
print "Starting process 1... ";
$start = Time::HiRes::time();
...[process code]
print "(" . (Time::HiRes::time() - $start) . " seconds)\n";

print "Starting process 2... ";
$start = Time::HiRes::time();
...[process code]
print "(" . (Time::HiRes::time() - $start) . " seconds)\n";
[download]