An integrated circuit with support for memory atomicity comprises a processor core. The processor core comprises a data cache unit (DCU), a store buffer (SB), a retirement unit, and memory atomicity facilities. The memory atomicity facilities are configured, when engaged, to (a) add an SB entry to the SB, in response to the processor core executing a store instruction that is part of an atomic region of code; (b) cause the SB entry to become senior, in response to the retirement unit retiring the store instruction; and (c) cause the SB entry to become walk enabled, in response to the retirement unit committing a transaction associated with the atomic region. Other embodiments are described and claimed.