Fast on Average, Predictable in the Worst Case: Exploring Real-Time Futexes in LITMUSRT

Autor:	Bjorn B. Brandenburg, Sven Dziadek, Manohar Vanga, Roy Spliet
Předmět:	Record locking Seqlock business.industry Computer science Context (language use) Linux kernel computer.software_genre Futex Priority inheritance Overhead (business) Embedded system Operating system business computer Real-time operating system
Zdroj:	BASE-Bielefeld Academic Search Engine RTSS
Popis:	This paper explores the problem of how to improve the average-case performance of real-time locking protocols, preferably without significantly deteriorating worst-case performance. Motivated by the futex implementation in Linux, where uncontended lock operations under the Priority Inheritance Protocol (PIP) do not incur mode-switching overheads, we extend this concept to more sophisticated protocols, namely the PCP, the MPCP and the FMLP+. We identify the challenges involved in implementing futexes for these protocols and present the design and evaluation of their implementations in LITMUSRT, a real-time extension of the Linux kernel. Our evaluation shows substantial improvements in the uncontended case (e.g., A futex implementation of the PCP lowers lock acquisition and release overheads by up to 75% and 92%, respectively), at the expense of some increases in worst-case overhead on par with Linux's existing futex implementation.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::abb74b2fb76fbacda657cc32757540b5 https://publications.cispa.saarland/420/ Zobrazit plný text záznamu