Most multiprocessor topics are already covered by other sections, especially distributed systems. We will assume that the system has several CPUs, each with local memory, and global memory. The owner of a page keeps track of who is caching the page at any time. Page ownership changes dynamically, depending on who wrote to it last.
Potential performance is higher.
There are two ways to store page ownership information. One processor stores all of the data. Obviously, that one processor becomes a bottleneck. This may get outdated if the page migrates again, but is updated using the following protocol. Each processor stores who it thinks is the owner.