Repository logo

Infoscience

  • English
  • French
Log In
Logo EPFL, École polytechnique fédérale de Lausanne

Infoscience

  • English
  • French
Log In
  1. Home
  2. Academic and Research Output
  3. Conferences, Workshops, Symposiums, and Seminars
  4. Selective, accurate, and timely self-invalidation using last-touch prediction
 
conference paper

Selective, accurate, and timely self-invalidation using last-touch prediction

Lai, An-Chow
•
Falsafi, Babak  
2000
Proceedings of the International Symposium on Computer Architecture

Communication in cache-coherent distributed shared memory (DSM) often requires invalidating (or writing back) cached copies of a memory block, incurring high overheads. This paper proposes Last-Touch Predictors (LTPs) that learn and predict the “last touch” to a memory block by one processor before the block is accessed and subsequently invalidated by another. By predicting a last-touch and (self-)invalidating the block in advance, an LTP hides the invalidation time, significantly reducing the coherence overhead. The key behind accurate last-touch prediction is trace-based correlation, associating a last-touch with the sequence of instructions (i.e. a trace) touching the block from a coherence miss until the block is invalidated. Correlating instructions enables an LTP to identify a last-touch to a memory block uniquely throughout an application's execution. In this paper we use results from running shared-memory applications on a simulated DSM to evaluate LTPs. The results indicate that: (1) our base case LTP design maintaining trace signatures on a per-block basis, substantially improves prediction accuracy over previous self-invalidation schemes to an average of 79%; (2) our alternative LTP design, maintaining a global trace signature table, reduces storage overhead but only achieves an average accuracy of 58%; (3) last-touch prediction based on a single instruction only achieves an average accuracy of 41% due to instruction reuse within and across computation; and (4) LTP enables selective, accurate, and timely self- invalidation in DSM, speeding up program execution on average by 11%

  • Files
  • Details
  • Metrics
Loading...
Thumbnail Image
Name

isca00.pdf

Access type

openaccess

Size

140.26 KB

Format

Adobe PDF

Checksum (MD5)

d2f5fecb4a6b7e19a2118e4ac3a608ec

Logo EPFL, École polytechnique fédérale de Lausanne
  • Contact
  • infoscience@epfl.ch

  • Follow us on Facebook
  • Follow us on Instagram
  • Follow us on LinkedIn
  • Follow us on X
  • Follow us on Youtube
AccessibilityLegal noticePrivacy policyCookie settingsEnd User AgreementGet helpFeedback

Infoscience is a service managed and provided by the Library and IT Services of EPFL. © EPFL, tous droits réservés