1. In a shared-memory computing system having two or more processors operatively coupled to a shared memory and to associated incoherent caches that cache copies of data stored in said memory, a method for implementing read-copy update, comprising: recording cacheline information for data that has been rendered obsolete due to a data update being performed by one of said processors; communicating said recorded cacheline information to one or more other of said processors; and using said communicated cacheline information to flush said obsolete data from all of said incoherent caches that may be caching said obsolete data.