Comment 4 for bug 516325

If it is a 2.6.32-13.18 kernel, then the patch is included. Now for usage, from the description I would say without it and a high latency announced C2 would not get used at all. If you see usage of C2 then I would say the patch works. But with a high latency announced the system less often will select C2 as it considers the longer time to get out of that.