Predictable Spin Lock Algorithms with Preemption

Both predictable interprocessor synchronization and fast interrupt response are required for real-time systems constructed using asymmetric shared-memory multiprocessors. This paper points out the problem that conventional spin lock algorithms cannot satisfy both requirements at the same time. To solve this problem, we have proposed an algorithm which is an extension of queueing spin locks modified to be preemptable for servicing interrupts [1]. In this paper, we propose an improved algorithm that minimizes the recovering overhead from an interrupt service. We also demonstrate that the proposed algorithms have required properties through performance measurement.