A method, apparatus, and computer program product are disclosed for a simultaneous multithreading (SMT) data processing system for modifying the processing of software threads that acquire a contentious software lock. The system includes a processor that is capable of concurrently executing multiple different threads on the processor. The processor is also capable of utilizing hardware thread priorities assigned to each thread the processor is processing by granting a greater, disparate amount of resources to the highest priority thread. A hardware priority is assigned to each one of the SMT threads. A contentious lock is identified. Ones of the multiple threads are identified that attempt to acquire the contentious lock. These threads are dynamically redirected to special code for handling contentious locks. The hardware priority of a thread acquiring a contentious lock is then boosted. According to the preferred embodiment, the present invention redirects callers of a locking function to a "hot" locking function when the lock they are acquiring has been classified as "hot", and vice versa.