Implied directory state updates

摘要

A request is received over a link that requests a particular line in memory. A directory state record is identified in memory that identifies a directory state of the particular line. A type of the request is identified from the request. It is determined that the directory state of the particular line is to change from the particular state to a new state based on the directory state of the particular line and the type of the request. The directory state record is changed, in response to receipt of the request, to reflect the new state. A copy of the particular line is sent in response to the request.

主权项

1. An apparatus comprising:
a memory controller to:
receive a request over a link, wherein the request requests a particular line in memory, and wherein the request originates from a particular caching agent;identify a directory state record in memory, wherein the directory state record identifies a directory state of the particular line;identify, from the request, a type of the request;determine that the directory state of the particular line is to change from the particular state to a new state based on the request, wherein the change is to be determined from the directory state of the particular line, the type of the request, and a type of the particular caching agent; andchange the directory state record, in response to receipt of the request, to reflect the new state; and logic to send a copy of the particular line in response to the request.