Thread-level speculation with kernel support

Runtime systems for speculative parallelization can be substantially sped up by implementing them with kernel support. We describe a novel implementation of a thread-level speculation (TLS) system using virtual memory to isolate speculative state, implemented in a Linux kernel module. This design choice not only maximizes performance, but also allows to guarantee soundness in the presence of system calls, such as I/O. Its ability to maintain speedups even on programs with frequent mis-speculation, significantly extends its usability, for instance in speculative parallelization. We demonstrate the advantage of kernel-based TLS on a number of programs from the Cilk suite, where this approach is superior to the state of the art in each single case (7.28× on average). All systems described in this paper are made available as open source.

• Type: Journal
• Year: 2016
• Where: CC
• Authors: Clemens Hammacher, Kevin Streit, Andreas Zeller, Sebastian Hack
• Keywords: CC 2016, System Software