What is a Warm-Up Cache?

Question

I am working with some multicore simulators such as GEMS or M5. In all of them there is an option to "Warm up the cache". What does that term mean?

Answer 1

The warm up is just the period of loading a set of data so that the cache gets populated with valid data. If you're doing performance testing against a system that usually has a high frequency of cache hits, without the warm up you'll get false numbers because what would normally be a cache hit in your usage scenario is not and will drag your numbers down.