Dvé: Coherent Replication Protocol

Dvé is a memory system architecture to improve the reliability and performance of DRAM main memory. This repository contains all artifacts used to experimentally evaluate Dvé [ISCA '21 paper].

Features of Dvé:

• Replicates memory on two different sockets of a multi socket NUMA system
• Modifies NUMA cache coherence communication by introducing replica directory to permit local replica access
  _{(Figure shows coherence communications in (a) Baseline NUMA (b) Dvé (c) Logical View)}
• Proposes two protocol families — allow-based and deny-based — to achieve Coherent Replication
• Protocol Optimizations to further improve performance
  • Speculative replica access
  • Coarse-grained replica directory
  • Sampling based dynamic protocol

Repository contents

1. gem5 based implementation of Coherent Replication (forked from VANDAL/SynchroTrace-gem5)
   The repo contains implementation of the baseline, proposed protocols and a variant of Intel's Mirroring implementation.

   • numa-baseline: multi-socket NUMA baseline configuration
   • deny-based protocol implementation
   • allow-based protocol implementation
   • intel-intel-ch-replication: An extention of Intel's Address Range Partial Mirroring implementation with read requests load balanced between both channels (requests are alternated between channels)

2. Trace generator (forked from VANDAL/prism)

3. Coherence protocol specification in table format.

4. Murphi model for allow-based and deny-based protocol (generated using ProtoGen)

Additional Material

• Full Protocol Model Checking and Verification files are available in this github source repo

• FAQ, talk videos, slides - https://adar.sh/dve

Referencing our work

If you are using Dvé for your work, please cite:**

@inproceedings{dve-isca21,
	author = {Patil, Adarsh and Nagarajan, Vijay and Balasubramonian, Rajeev and Oswald, Nicolai},
	title = {Dvé: Improving DRAM Reliability and Performance On-Demand via Coherent Replication},
	year = {2021},
	publisher = {IEEE Press},
	booktitle = {Proceedings of the ACM/IEEE 48th Annual International Symposium on Computer Architecture},
	pages = {526–539},
	numpages = {14},
	keywords = {Memory Systems, DRAM, Reliability, Coherence},
	location = {Virtual Event},
	series = {ISCA '21}
}

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The title of the project is derived from the Sankrit word (द्वे) which means "the two", referring here to the dual benefits of replication.