How to find out on which core a thread is running on?

Let's say we have a CPU-intensive application called multi-threaded-application.out that is running on top of Ubuntu with a PID of 10000. It has 4 threads with tid 10001, 10002, 10003, and 10004. I want to know, at any given time, on which core each of these threads is being scheduled? I tried /proc//tasks//status, but I couldn't find any information regarding the core ID that is responsible for running the given thread. This question is somehow related to this one . Any help would be much appreciated.