Cache memory with dynamic lockstep support

摘要

Cache storage may be partitioned in a manner that dedicates a first portion of the cache to lockstep mode execution, while providing a second (or remaining) portion for non-lockstep execution mode(s). For example, in embodiments that employ cache storage organized as a set associative cache, partition may be achieved by reserving a subset of the ways in the cache for use when operating in lockstep mode. Some or all of the remaining ways are available for use when operating in non-lockstep execution mode(s). In some embodiments, a subset of the cache sets, rather than cache ways, may be reserved in a like manner, though for concreteness, much of the description that follows emphasizes way-partitioned embodiments.

主权项

1. A method comprising:
operating a computational system that includes a plurality of processors each having an associated cache way- or set-partitioned into lockstep and non-lockstep partitions; dynamically transitioning between a lockstep mode of operation and a non-lockstep mode of operation, wherein in the lockstep mode of operation, the plural processors each execute a same code sequence in temporal correspondence, and wherein in the non-lockstep mode of operation, the plural processors are capable of executing differing code sequences; in the non-lockstep mode, satisfying at least some load hits from the lockstep partition and at least some other load hits from the non-lockstep partition; and in the lockstep mode, satisfying load hits only from the lockstep partition.