Hello, I am using the 'perf' tool for evaluation purposes. I know that there are some predefined "Hardware Events" for my platform (Intel Core 2 Duo), e.g. cycles and instructions. My question is: which internal event number is used to calculate the stats for cycles / instructions etc.? Could you give me a hint where in the source code these alias names are translated into the real hardware event numbers? I have already tried to find it, but I didn't succeed. Is there a docu/homepage where the several events are described in more detail? E.g. what does "instructions" stand for? The number of CPU instructions executed while the given program is running? Am I correct that on a platform with Level1 and Level2 cache, LLC (last level cache) = L2 ? Thanks for your efforts, Andreas Leppert