Described embodiments generate tasks corresponding to packets received by a network processor. A source processing module sends task messages including a task identifier and a task size to a destination processing module. The destination module receives the task message and determines a queue in which to store the task. Based on a used cache counter of the queue and a number of cache lines for the received task, the destination module determines whether the queue has reached a usage threshold. If the queue has reached the threshold, the destination module sends a backpressure message to the source module. Otherwise, if the queue has not reached the threshold, the destination module accepts the received task, stores data of the received task in the queue, increments the used cache counter for the queue corresponding to the number of cache lines for the received task, and processes the received task.