What core is running my process?

I am currently taking a parallel programming class and our first programming exercise was to create four threads that displayed a "hello world" kinda of message. I wou开发者_开发技巧ld like to know what cores are running the threads. I have tried using the TOP command on Unix to display all processes and I do see the 5 different threads, but not sure how to see what cores are running each thread.

Field j of top, P, shows you which core the thread/process last ran on.