摘要 |
A system permits unacknowledged write backs in a computer. The computer has a plurality of processors and a shared memory. The shared memory stores data in terms of memory blocks, and each processor has a cache. Associated with each cache line is a tag containing the address of the block at that line, and its state. A duplicate copy of the tag information (DTAG) for each processor cache is also provided, and each section of the DTAG that corresponds to a given processor is organized into a primary DTAG region and a secondary DTAG region. The secondary DTAG region preferably stores tag information for a dirty version of a block, while the write back of the block is in flight to memory. This frees the primary DTAG region to store tag information for a block other than the dirty block, but using the same cache line.
|