Increasing of cache reliability lifetime through dynamic invalidation and deactivation of problematic cache lines

Abstract

A system captures errors and stores an obsolete line bit qualifier per cache entry that can be used to dynamically mark a specific cache entry as obsolete. For example, the cache entry can be marked as obsolete after detecting repetitive single-bit errors on a same cache entry within a predetermined period of time. For cache lines marked as obsolete, a cache controller can ensure that the cache line entry remains unused. The detection of a repetitive single-bit error can be accomplished by implementing a counter per cache entry and a timer. The counter counts errors within a timer window, and a repetitive error is reported if the counter reaches a threshold level. By catching repetitive single-bit errors before such errors spread to multi-bit errors, the system can increase the life span of the server computer.