In addition to what vcTheGuru said, here are some other things to consider.

Using an alternate delimiter for your regex would make it easier on the eye, and would avoid LTS (Leaning Toothpick Syndrome). Instead of "/", you could use "{}", for example:

    m{  Input queue: 0/75/(.*)/39 \(size/max/drops/flushes\); Total ou
+tput drops: (.*)}
[download]

Also consider making portions of the regex independent of whitespace. You could start the regex with m{\s+Input

The $1 alone looks a little suspicous. If the regex matches, then $1 should be set, so checking it again seems redundant. Did you really mean if (($1 != 0) || ($2 != 0))

If your captures should always be integers, it might be better to use (\d+) instead of (.*).