一句话：将页式虚拟内存替换为编译器与内核协作的 CARAT CAKE，以低开销实现保护、映射与移动。
虚拟内存的页式机制面临现代负载的新需求。先前 CARAT 用编译器与运行时完成地址翻译，甚至支持纯物理寻址，但仅停留在用户级原型。本文将其引入内核，形成 CARAT CAKE，使 Linux 兼容的 x64 进程抽象可基于该机制或页式实现。实现需修改内核，并让编译器优化/变换覆盖包括内核代码在内的全系统代码。与页式对比评估显示，CARAT CAKE 以极小开销实现保护、映射与移动功能，并带来节能、更大 L1 缓存和任意粒度内存管理等收益。
Virtual memory, specifically paging, is undergoing significant innovation due to being challenged by new demands from modern workloads. Recent work has demonstrated an alternative software only design that can result in simplified hardware requirements, even supporting purely physical addressing. While we have made the case for this Compiler- And Runtime-based Address Translation (CARAT) concept, its evaluation was based on a user-level prototype. We now report on incorporating CARAT into a kernel, forming Compiler- And Runtime-based Address Translation for CollAborative Kernel Environments (CARAT CAKE). In our implementation, a Linux-compatible x64 process abstraction can be based either on CARAT CAKE, or on a sophisticated paging implementation. Implementing CARAT CAKE involves kernel changes and compiler optimizations/transformations that must work on all code in the system, including kernel code. We evaluate CARAT CAKE in comparison with paging and find that CARAT CAKE is able to achieve the functionality of paging (protection, mapping, and movement properties) with minimal overhead. In turn, CARAT CAKE allows significant new benefits for systems including energy savings, larger L1 caches, and arbitrary granularity memory management.
@inproceedings{SuchyGKCHNCBCHC22,
title = {CARAT CAKE: replacing paging via compiler/kernel cooperation},
author = {Brian Suchy and Souradip Ghosh and Drew Kersnar and Siyuan Chai and Zhen Huang and Aaron Nelson and Michael Cuevas and Alex Bernat and Gaurav Chaudhary and Nikos Hardavellas and Simone Campanoni and Peter Dinda},
booktitle = {ASPLOS},
year = {2022},
doi = {10.1145/3503222.3507771}
}