MetaTM/TxLinux: Transactional Memory for an Operating System

Overview

This paper quantifies the effect of architectural design decisions on the performance of TxLinux. TxLinux is a Linux kernel modified to use transactions in place of locking primitives in several key subsystems. The authors run TxLinux on MetaTM, which is a new Hardware Transaction Memory (HTM) model. MetaTM contains features that enable efficient and correct interrupt handling for an x86-like architecture. Live stack overwrites can corrupt non-transactional stack memory and requires a small change to the transaction register checkpoint hardware to ensure correct operation of the operating system. The paper also proposes stack-based early release to reduce spurious conflicts on stack memory between kernel code and interrupt handlers.