Overlap of Cache-To-Cache Transfer With Outpage Operation Within a Dual-Processor Machine
Original Publication Date: 1987-Mar-01
Included in the Prior Art Database: 2005-Feb-01
In a dual-processor machine, cache-to-cache transfer operations are the means in which modified cache pages are moved from the cache of one processor to the cache of the other. In the general case a storage microword is issued which gets a cache miss. The cache directory least recently used (LRU) algorithm points to an invalid, or unmodified, cache slot, and an inpage operation is started. A search in the other processor's cache directory finds the desired data with a modified status. The inpage operation is then terminated, and a cache-to-cache operation is executed instead. No penalty of extra machine cycles is incurred.