Don’t Sit on the Fence

Abstract

Modern architectures rely on memory fences to prevent undesired weakenings of memory consistency. As the fences’ semantics may be subtle, the automation of their placement is highly desirable. But precise methods for restoring consistency do not scale to deployed systems’ code. We choose to trade some precision for genuine scalability: our technique is suitable for large code bases. We implement it in our new musketeer tool and report experiments on more than 700 executables from packages found in Debian GNU/Linux 7.1, including memcached with about 10,000 LoC.