QUEST

Time as a first-class resource. Quest aims to support "time as a first-class resource". From the ground up, Quest manages all resources via time-budgeted and temporally-isolated virtual CPUs (VCPUs). The system features a hierarchical scheduling infrastructure, with both main and IO VCPUs to handle the execution of conventional tasks and system events associated with interrupts. This means that real-time and non-real-time tasks can co-exist without interference, at least in terms of the resource time budgets they are guaranteed. This does not, however, guarantee the amount of progress a task makes in real-time, because micro-architectural resource contention is still possible. For example, one task may evict another's memory contents from a shared on-chip cache, or may compete for memory bus bandwidth. These factors all affect the execution time of tasks... To ensure efficient progress is made by all tasks, and to try to bound the amount of interference between tasks caused by micro-..