2024/01/17 by Samuel Riedel, Riedel, Samuel, Marc Gantenbein +7
Computer Science · Engineering · #Advanced Memory and Neural Computing #Distributed systems and fault tolerance #FOS: Computer and information sciences #Hardware Architecture (cs.AR) #Parallel Computing and Optimization Techniques
paper · pdf · doi:10.48550/arxiv.2401.09359
openalex publication_date 2024/01/17 · openalex created_date 2024/01/19 · openalex updated_date 2026/07/28
Extensive polling in shared-memory manycore systems can lead to contention, decreased throughput, and poor energy efficiency. Both lock implementations and the general-purpose atomic operation, load-reserved/store-conditional (LRSC), cause polling due to serialization and retries. To alleviate this overhead, we propose LRwait and SCwait, a synchronization pair that eliminates polling by allowing contending cores to sleep while waiting for previous cores to finish their atomic access. As a scalable implementation of LRwait, we present Colibri, a distributed and scalable approach to managing LRwait reservations. Through extensive benchmarking on an open-source RISC-V platform with 256 cores, we demonstrate that Colibri outperforms current synchronization approaches for various concurrent algorithms with high and low contention regarding throughput, fairness, and energy efficiency. With an area overhead of only 6%, Colibri outperforms LRSC-based implementations by a factor of 6.5x in terms of throughput and 7.1x in terms of energy efficiency.