Patent ID: 9208092
Filing Date: 2015-12-08
Classification: G06F

Abstract:
1. A method of data processing, comprising: at a coherent attached processor proxy (CAPP) of a primary coherent system that serves as a participant in coherent communication within the primary coherent system on behalf of an attached processor (AP) external to the primary coherent system, maintaining, in a CAPP directory, entries corresponding to cachelines of interest to the AP that belong to a coherent address space of the primary coherent system, wherein the maintaining includes maintaining in a precise directory a plurality of entries each associated with a respective one of a plurality of smaller data granules and maintaining in a coarse directory a plurality of entries each associated with a respective one of a plurality of larger data granules; the CAPP participating in coherent communication on a system fabric of the primary coherent system on behalf of the AP by reference to the coarse directory and the precise directory; and the CAPP installing an entry in the coarse directory in a data-valid coherence state in advance of receipt of all of the larger data granule by the AP.