1. A method of scheduling synchronization in association with collective operations in a parallel computer, the parallel computer comprising a shared memory and a plurality of compute nodes that execute a parallel application utilizing the shared memory, the method comprising: acquiring, by the parallel application, an available channel of the shared memory; posting to the acquired channel of the shared memory, by the parallel application, one or more collective operations and a synchronization point; determining, by the parallel application, that processing within the acquired channel has reached the synchronization point; and in response to determining that processing within the acquired channel has reached the synchronization point, posting to the acquired channel, by the parallel application, a background synchronization operation corresponding to the one or more collective operations.