1. A computer-implemented method, comprising: instrumenting a program to detect accesses to program methods associated with a need for responsiveness; while executing the instrumented program in a virtual machine, gathering statistics about accesses to the program methods associated with a need for responsiveness, wherein gathering the statistics includes: incrementing a value of a counter when a program method associated with a need for responsiveness is accessed, wherein the value of the same counter is incremented when any program method associated with a need for responsiveness is accessed, and wherein the value of the counter is decayed or decremented over time; dynamically tuning the virtual machine, based on the gathered statistics, including the value of the counter, wherein the tuning includes one of prioritizing responsiveness over throughput and prioritizing throughput over responsiveness, wherein the value of the counter indicates which one of responsiveness and throughput should be prioritized under current usage conditions of the program.