Memory coherence vs consistency
Coherence deals with maintaining a global order in which writes to a single location or single variable are seen by all processors. Consistency deals with the ordering of operations to multiple locations with respect to all processors.
Memory coherence: a memory system is coherent if any read of a data item returns the most recently written value of that data item (what values can be returned by a read).
Memory consistency: A memory consistency model for a shared address space specifies constraints on the order in which memory operations must appear to be performed (i.e. to become visible to the processors) with respect to one another.(when a written value will be returned/seen by a read).
Coherence defines the behavior of reads and writes to the same memory location, while consistency defines the behavior of reads and writes with respect to accesses to other locations.
这里应该想要区分还是内存一致性（coherence）和内存顺序一致性（sequential consistency）。