teamassociated:

Because you have two CPUs, and a hash holds one item. So the last one read wins for each CPU. Try this to get a hash of arrays (HoA):

push @{$prochash{$cpu}}, {
         'pid'  => $pid,
         'time' => $time,
         'user' => $user,
         'args' => $args,
};
[download]

Or if you want a hash of hashes (HoH), use the first level for the CPU and the second for the PID:

$prochash{$cpu}{$pid} = {
        'pid'  => $pid,
        'time' => $time,
        'user' => $user,
        'args' => $args,
};
[download]

There are other ways to do it, too. You may want to review perldoc perldsc

Update: Changed language a little to clarify.

...roboticus

When your only tool is a hammer, all problems look like your thumb.