METHOD AND SYSTEM FOR AVOIDING LOSS OF DATA CAUSED BY CANCEL OF TRANSACTION IN UNEQUAL MEMORY ACCESS SYSTEM

摘要

PROBLEM TO BE SOLVED: To avoid the loss of data and coherence by respectively providing first and second nodes with a local mutual connection, a system memory coupled with the local mutual connection and a node controller located between the local mutual connections. SOLUTION: A READ request in a home node 10a is transferred to a remote node 10b where corrected data are resident. Concerning the READ request, the boat of correction/intervention is received by the remote node 10b. The remote node 10b returns the corrected/intervened boat and the corrected data to the home node 10a. A node controller 20 generates a new tag and issue the write back kill (WBC request) of R bit = 1. A coherence mechanism in the node controller 20 completes the WBC request like ReRum of locally generated WBC requests. In this case, data in a local memory 18 are made effective.