Dynamic self-invalidation: reducing coherence overhead in shared-memory multiprocessors

Conference Paper

This paper introduces dynamic self-invalidation (DSI), a new technique for reducing cache coherence overhead in shared-memory multiprocessors. DSI eliminates invalidation messages by having a processor automatically invalidate its local copy of a cache block before a conflicting access by another processor. Eliminating invalidation overhead is particularly important under sequential consistency, where the latency of invalidating outstanding copies can increase a program's critical path. DSI is applicable to software, hardware, and hybrid coherence schemes. In this paper we evaluate DSI in the context of hardware directory-based write-invalidate coherence protocols. Our results show that DSI reduces execution time of a sequentially consistent full-map coherence protocol by as much as 41%. This is comparable to an implementation of weak consistency that uses a coalescing write-buffer to allow up to 16 outstanding requests for exclusive blocks. When used in conjunction with weak consistency. DSI can exploit tear-off blocks - which eliminate both invalidation and acknowledgment messages - for a total reduction in messages of up to 26%.

Duke Authors

Cited Authors

  • Lebeck, AR; Wood, DA

Published Date

  • January 1, 1995

Published In

  • Acm Sigarch (Association for Computing Nachinery Special Interest Group on Computer Architecture) Conference Proceedings

Start / End Page

  • 48 - 59

Citation Source

  • Scopus