Bus-Contention Aware Schedulability Analysis for the 3-Phase Task Model with Partitioned Scheduling

Bus-contention aware WCRT analysis for the 3-phase task model considering a work-conserving bus arbitration scheme

“…Due to this sharing, when a task running on a given core requests access to the bus to fetch its data/instructions from the main memory, it may suffer bus contention if the bus is already busy serving the requests of another task executing on some other core of the same multicore platform. It has been shown by several works [1,2,3,4,5,6,7,8,9,10,11,12] that the bus contention suffered by tasks executing on a multicore platform can have a significant impact on the Worst-Case Execution Time (WCET) and the Worst-Case Response Time (WCRT) of tasks.…”

“…This ensures that tasks can issue memory requests only during their memory phase(s), which facilitates the analysis of the bus contention that can be suffered by tasks. Under the umbrella of phased-execution models, the 3-phase execution model has received much attention from industry and academia [14,15,8,16,10,17,18,19,12,20,21,22,23]. In the 3-phase task execution model, the execution of a task is divided into three phases Acquisition (A-phase), Execution (E-phase), and Restitution (R-phase).…”

“…Few existing works [10,8,12] have focused on analyzing the bus contention that can be suffered by tasks executed using the 3-phase execution model. Maia et al [10] have presented a bus contention aware WCRT analysis for the 3-phase tasks scheduled using global fixed-priority non-preemptive scheduling.…”

“…Schranzhofer et al [8] have proposed a bus contention aware WCRT analysis for partitioned fixed-priority non-preemptive scheduling assuming a Time-Division Multiple Access (TDMA) based bus arbiter. Similarly, Arora et al [12] have presented a schedulability analysis for the 3-phase tasks that are scheduled using partitioned fixedpriority non-preemptive scheduling and the bus arbitration policy is assumed to be First-Come-First-Serve (FCFS). The arbitration policy considered at the bus can have a strong impact on the bus contention that can be suffered by the tasks.…”

Schedulability analysis for 3-phase tasks with partitioned fixed-priority scheduling

“…The additional execution delay suffered by τ i in Figure 3 is referred to as bus blocking 1 . Bus blocking suffered by tasks executing on a multicore platform can have a significant impact on their schedulability.…”