Lock-Free and Wait-Free Slot Scheduling Algorithms

• Published in: IEEE transactions on parallel and distributed systems Vol. 27; no. 5; pp. 1387 - 1400
• Main Authors: Aggarwal, Pooja, Sarangi, Smruti R.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.05.2016; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Arrays; Design engineering; Instruction sets; Jitter; Locks; Processor scheduling; Reserves; Schedules; Scheduling; Scheduling algorithms; Servers (computers); Video data; Wait free; scheduler; lock free; slot scheduling
• ISSN: 1045-9219; 1558-2183
• DOI: 10.1109/TPDS.2015.2435786

In this paper, we consider the design space of parallel non-blocking slot scheduling algorithms. Slot schedulers divide time into discrete quanta called slots, and schedule resources at the granularity of slots. They are typically used in high throughput I/O systems, data centers, video servers, and network drivers. We propose a family of parallel slot scheduling problems of increasing complexity, and then propose parallel lock-free and wait-free algorithms to solve them. In specific, we propose problems that can reserve, as well as free a set of contiguous slots in a non-blocking manner. We show that in a system with 64 threads, it is possible to get speedups of 10X by using lock-free algorithms as compared to a baseline implementation that uses locks. We additionally propose wait-free algorithms, whose mean performance is roughly the same as the version with locks. However, they suffer from significantly lower jitter and ensure a high degree of fairness among threads.