Revisiting Residue Codes for Modern Memories

TL;DR

This paper explores adapting residue codes for modern memory error correction, demonstrating they can provide comparable protection to traditional schemes with fewer bits, enabling enhanced security and efficiency.

Contribution

It introduces a novel adaptation of residue codes for storage error correction, achieving comparable reliability with fewer bits and enabling new security features.

Findings

Residue codes can be effectively used for storage error correction.

MUSE ECC provides ChipKill protection with 30% fewer bits.

Memory tagging with MUSE reduces bandwidth by 12%.

Abstract

Residue codes have been traditionally used for compute error correction rather than storage error correction. In this paper, we use these codes for storage error correction with surprising results. We find that adapting residue codes to modern memory systems offers a level of error correction comparable to traditional schemes such as Reed-Solomon with fewer bits of storage. For instance, our adaptation of residue code -- MUSE ECC -- can offer ChipKill protection using approximately 30% fewer bits. We show that the storage gains can be used to hold metadata needed for emerging security functionality such as memory tagging or to provide better detection capabilities against Rowhammer attacks. Our evaluation shows that memory tagging in a MUSE-enabled system shows a 12% reduction in memory bandwidth utilization while providing the same level of error correction as a traditional ECC baseline without a noticeable loss of performance. Thus, our work demonstrates a new, flexible primitive for co-designing reliability with security and performance.