Aspects of the subject matter described herein relate to semaphores. In aspects, a feedback mechanism is described that uses a semaphore to attempt to maximize throughput of a computer system. Throughput is tracked over periods of time. At or after the end of a period of time, the throughput of the period of time together with other data is used to determine whether a max count for a semaphore is to be changed and by how much. This monitoring of throughput and modifying of the max count may continue over subsequent periods of time to attempt to maximize throughput.