McZero: Memory-Controller–Supported Page Zeroing with LPDDR6 Metadata

DIMES Workshop
McZero: Memory-Controller–Supported Page Zeroing with LPDDR6 Metadata

Alexander Halbuer, Illia Ostapyshyn, Nils Wilbert, Derek Christ, Matthias Jung, Daniel LohmannProceedings of the 4th Workshop on Disruptive Memory Systems (DIMES '26)Association for Computing Machinery2026.
PDF Details Slides 10.1145/3831664.3837784 [BibTex]

BibTex Entry

@inproceedings{halbuer:26:dimes,
author = {Alexander Halbuer and Illia Ostapyshyn and Nils Wilbert and Derek Christ and Matthias Jung and Daniel Lohmann},
booktitle = {Proceedings of the 4th Workshop on Disruptive Memory Systems (DIMES '26)},
date = {2026-09-28},
doi = {10.1145/3831664.3837784},
entrysubtype = {Workshop},
location = {Prague, Czech Republic},
publisher = {Association for Computing Machinery},
title = {McZero: Memory-Controller–Supported Page Zeroing with LPDDR6 Metadata},
year = {2026},
}

Abstract

Computer systems are increasingly bottlenecked by memory performance. A common OS operation is page-frame zeroing: to prevent data leakage, the kernel must initialize pages before exposing them to user mode, consuming compute, bandwidth, and energy resources.

McZero replaces eager zeroing by the CPU with a lazy approach that merely marks pages as zeroed and lets the memory controller return zero bytes on first access. Our implementation leverages the LPDDR6 metadata feature, exposed to the OS for storing these marks.

Using gem5 to emulate an ARMv8 system with LPDDR6 running Linux 6.18, we show that the zeroing time and en ergy for a 2 MiB page is reduced by more than 95 percent.