The simplest solution for finding the owner is by doing a broadcast, asking for the owner of the specified page to respond. An optimization is not just to ask who the owner is, but also to tell whether the sender wants to read or write and say whether it needs a copy of the page. The owner can then send a single message transferring ownership and the page is well, if needed. Broadcasting has the disadvantage of interrupting each processor, forcing it to inspect the request packet. For all the processors except the owner's, handling the interrupt is essentially wasted time.
Broadcasting can use up considerable bandwidth, depending on the hardware.
There could be several other possibilities as well. In one of these, a process is designated as the page manager . It is the job of the manager to keep track of who owns each page. When a process, P, wants to read a page it does not have or wants to write a page it does not own, it sends a message to the page manager telling which operation it wants to perform and on which page. The manager then sends back a message telling the ownership, as required.