1. A computer system, comprising: a processor; a cache connected to the processor, wherein the cache is partitioned into a locking cache and a non-locking cache; a cache controller connected to the processor and the cache; a system bus connected to the cache; an I/O subsystem connected to the system bus; wherein the cache controller is configured to receive a store instruction from the processor and determine whether the store instruction is intended for the locking cache; wherein the processor is configured to write data to the locking cache without also writing it to system memory if the store instruction is intended for the locking cache; and wherein the locking cache is at least configured to retain the data until the data has been accessed for use by the I/O subsystem.