Linux is a GP (General Purpose) OS (Operating System) that has gained many features of RT (Real-Time) OS over the last decade. For instance, nowadays Linux has a fully preemptive mode, and a deadline-oriented scheduler . Although many of these features are part of the official Linux kernel, many of them are still part of an external patch set, the PREEMPT-RT . The PREEMP-RT changes the locking methods of Linux to provide the control of unbounded priority inversion, by using the Priority Inheritance Protocol  on mutex, and bounds the activation delay for the highest priority task. Indeed, the latency is the main evaluation metric for the PREEMPT-RT Linux: for example, the Red Hat Enterprise Linux for Real-time  (based on PREEMPT-RT) shows a max latency of 150 μs on certified hardware. However, due to Linux’s GPOS nature, RT Linux developers are challenged to provide the predictability required for a RTOS, while not causing regressions on the general purpose benchmarks. As a consequence, the implementation of some well known algorithms, like read/write semaphores, has to be done using approaches that were not well explored in academic papers, which is the case of read/write semaphores.
|Titolo:||Nested Locks in the Lock Implementation: The Real-Time Read-Write Semaphores on Linux|
|Data di pubblicazione:||2018|
|Appare nelle tipologie:||4.1 Contributo Atti Congressi/Articoli in extenso|