Patent ID: 6108764
Filing Date: 2000-08-22
Classification: G06F

Abstract:
A computer system, comprising:first and second processing nodes coupled together, wherein said first processing node includes a system memory and a first processor having a first cache hierarchy and a second processor having a second cache hierarchy, and wherein said second processing node includes at least a system memory and a third processor having a third cache hierarchy;wherein said first cache hierarchy, responsive to receipt of a read request from the second processing node for a copy of an unmodified cache line held by said first cache hierarchy, sources a copy of said unmodified cache line to said third cache hierarchy and retains said unmodified cache line in a Recent coherency state from which said first cache hierarchy can source said cache line; andwherein said third cache hierarchy, responsive to receipt of said copy of said unmodified cache line, concurrently stores said cache line in said Recent state to permit said third cache hierarchy to also source said cache line.