1. A method of processing requests of a logically partitioned computer system comprising a plurality of logical partitions, said method comprising: obtaining by a receiving processing unit of the logically partitioned computer system a request of a sending processing unit of the logically partitioned computer system, said sending processing unit being associated with one logical partition of the logically partitioned computer system and the request including a logical partition identifier of the one logical partition, and the receiving processing unit being in the one logical partition or another logical partition of the logically partitioned computer system; determining whether the request is to be blocked by the receiving processing unit, wherein the determining comprises comparing the logical partition identifier of the request with a logical partition identifier of the receiving processing unit; blocking processing of the request by the receiving processing unit, in response to the comparing indicating a mismatch between the logical partition identifier of the request and the logical partition identifier of the receiving processing unit, wherein a mismatch indicates that the sending processing unit and the receiving processing unit are in different logical partitions, and wherein the blocking comprises indicating that the request has been performed by the receiving processing unit even though the request has not been performed by the receiving processing unit, and wherein the request is a quiesce request associated with a purge operation; and purging, by the receiving processing unit, one or more entries of one or more buffers corresponding to the purge operation, wherein the purging is performed at a time selected by the receiving processing unit.