1. A method of operating a cache memory of a data processing system, comprising: creating, by a pollution vector control, respective pollution vectors to track which of multiple concurrent threads executed by an associated processor core are currently polluted by a store operation resident in the cache memory; setting, by a store queue controller, dependencies in a dependency data structure of a store queue of the cache memory based on the pollution vectors to reduce unnecessary ordering effects; and dispatching store operations from the store queue in accordance with the dependencies indicated by the dependency data structure.