ACCELERATED RECOVERY FOR SNOOPED ADDRESSES IN A COHERENT ATTACHED PROCESSOR PROXY

摘要

A coherent attached processor proxy (CAPP) that participates in coherence communication in a primary coherent system on behalf of an external attached processor maintains, in each of a plurality of entries of a CAPP directory, information regarding a respective associated cache line of data from the primary coherent system cached by the attached processor. In response to initiation of recovery operations, the CAPP transmits, in a generally sequential order with respect to the CAPP directory, multiple memory access requests indicating an error for addresses indicated by the plurality of entries. In response to a snooped memory access request that targets a particular address hitting in the CAPP directory during the transmitting, the CAPP performs a coherence recovery operation for the particular address prior to a time indicated by the generally sequential order.

主权项

1. A method of data processing, comprising:
in a coherent attached processor proxy (CAPP) that participates in coherence communication in a primary coherent system on behalf of an attached processor external to the primary coherent system, maintaining, in each of a plurality of entries of a CAPP directory, information regarding a respective associated cache line of data from the primary coherent system cached by the attached processor, the information including an address tag; in response to initiation of recovery operations, the CAPP transmitting, for each of multiple entries in the CAPP directory, one of a corresponding plurality of memory access requests in the primary coherent system indicating an error for an address specified by the address tag of that entry, wherein the transmitting includes transmitting the plurality of memory access requests in a generally sequential order with respect to the CAPP directory; and in response to a snooped memory access request that targets a particular address hitting in the CAPP directory during the transmitting, the CAPP performing a coherence recovery operation for the particular address prior to a time indicated by the generally sequential order.