SYSTEM AND METHOD FOR ATOMICALLY UPDATING SHARED MEMORY IN MULTIPROCESSOR SYSTEM

摘要

A system for operating a shared memory of a multiprocessor system includes a set of processor cores and a corresponding set of core local caches, a set of I/O devices and a corresponding set of I/O device local caches. Read and write operations performed on a core local cache, an I/O device local cache, and the shared memory are governed by a cache coherence protocol (CCP) that ensures that the shared memory is updated atomically.

主权项

1. A method for operating a shared memory of a multiprocessor system, the multiprocessor system including a set of processor cores and a corresponding set of core local caches, and a set of input/output (I/O) devices and a corresponding set of I/O device local caches, the shared memory being shared between the set of processor cores and the set of I/O devices, the set of processor cores including at least one processor core and the set of I/O devices including at least one I/O device, the method comprising:
updating data stored in a core local cache of the set of core local caches by an associated processor core of the set of processor cores; transmitting the data stored in the core local cache to the shared memory after being updated by the processor core; flagging data stored in an I/O device local cache of the set of I/O device local caches as invalid by the processor core, subsequent to the transmission of the data stored in the core local cache to the shared memory; accessing the I/O device local cache by an associated I/O device of the set of I/O devices; determining a validity of the data stored in the I/O device local cache by the I/O device; reading the data stored in the I/O device local cache when the data is determined to be valid; and accessing data stored in the shared memory when the data stored in the I/O device local cache is determined to be invalid, wherein the data stored in the shared memory is accessed by the I/O device.