The system and methods described herein may reduce read/write fence latencies and cache pressure related to STM metadata accesses. These techniques may leverage locality information (as reflected by the value of a respective locale guard) associated with each of a plurality of data partitions (locales) in a shared memory to elide various operations in transactional read/write fences when transactions access data in locales owned by their threads. The locale state may be disabled, free, exclusive, or shared. For a given memory access operation of an atomic transaction targeting an object in the shared memory, the system may implement the memory access operation using a contention mediation mechanism selected based on the value of the locale guard associated with the locale in which the target object resides. For example, a traditional read/write fence may be employed in some memory access operations, while other access operations may employ an optimized read/write fence.