US Patent 7707556 Method and system to measure system performance

A method for measuring system performance involves binding a sampling thread to a central processing unit (CPU), starting a soaker thread and binding the soaker thread to the CPU, assigning the soaker thread a lowest priority and scheduling class, placing the soaker thread in a scheduling mechanism based on the lowest priority and scheduling class, and suspending the soaker thread. If a hardware counter is kernel-only, then the following steps are performed: initializing the hardware counters, resuming the soaker thread, and executing the soaker thread if there is no scheduler item of equal or higher priority, where the scheduler item is within the scheduling mechanism.