Flexible, low-overhead event logging to support resource scheduling

Flexible resource management and scheduling policies require detailed system-state information. Traditional, monolithic operating systems with a centralized kernel derive the required information directly, by inspection of internal data structures or maintaining additional accounting data. In systems with distributed or multi-level resource managers that reside in different subsystems and protection domains, direct inspection is unfeasible. In this paper, we present how system event logging - a mechanism usually used in the context of performance analysis and debugging - can also be used for resource scheduling. Event logs provide accumulated, pre-processed, and structured state information independent of the internal structure of individual system components or applications. We describe methods of low-overhead data collection and data analysis and present a prototypical application to multiprocessor scheduling of virtual machines