一句话：提出软硬件协同设计 Necro-reaper，用新 ISA 指令与配套编译器/分配器消除 WSC 中已释放和未初始化数据的死内存流量。
内存带宽是仓库级计算（WSC）的关键瓶颈。本文发现，WSC 中大量内存流量不必要，包括已释放数据的无谓写回和未初始化数据的读取；短生命周期且大于 cache line 的堆分配使问题更突出。为此，作者提出软硬件协同设计 Necro-reaper，利用 WSC 的垂直集成、profile-guided 编译和定制分配器，通过新增 ISA 指令避免死流量，无需以往工作的硬件跟踪；配套编译器与分配器优化这些指令的使用。在 10 个 WSC 负载上评估，内存流量几何平均降低 26%，IPC 几何平均提升 6%。
Memory bandwidth is emerging as a critical bottleneck in warehouse-scale computing (WSC). This work reveals that a significant portion of memory traffic in WSC is surprisingly unnecessary, consisting of needless writebacks of deallocated data and fetches of uninitialized data. This issue is particularly acute in WSC, where short-lived heap allocations bigger than a cache line are prevalent. To address this problem, this work proposes a pragmatic approach tailored to WSC. Leveraging the existing WSC ecosystem of vertical integration, profile-guided compilation flows, and customized memory allocators, this work presents Necro-reaper, a novel software/hardware co-design that avoids dead memory traffic without requiring the hardware tracking of prior work. New ISA instructions enable the hardware to avoid unnecessary dead traffic, while extended software components, including a profile-guided compiler and memory allocator, optimize the utilization of these instructions. Evaluation across a diverse set of 10 WSC workloads demonstrates that Necro-reaper achieves a geomean memory traffic reduction of 26% and a geomean IPC increase of 6%.
@inproceedings{ApostolakisKLR25,
title = {<scp>Necro-reaper:</scp>
Pruning away Dead Memory Traffic in Warehouse-Scale Computers},
author = {Sotiris Apostolakis and Chris Kennelly and Xinliang David Li and Parthasarathy Ranganathan},
booktitle = {ASPLOS},
year = {2025},
doi = {10.1145/3676641.3716007}
}