Setting a ceiling for bandwidth used by background tasks in a shared port environment

Controlling communication through a communication resource includes allocating a percentage of a maximum bandwidth of the communication resource to a subset of processes that communicate using the resource, determining a delay amount between I/O operations, where the delay amount corresponds to the percentage of bandwidth allocated to the subset of processes, and waiting an amount of time corresponding to the delay amount between I/O operations for the subset of processes. The delay amount may be increased in response to the actual I/O throughput being greater than an amount corresponding to the percentage of the maximum bandwidth allocated to the subset of processes. The delay amount may be decreased in response to the actual I/O throughput being less than an amount corresponding to the percentage of the maximum bandwidth allocated to the subset of processes.