Systems need to run a larger and more diverse set of applications, from real-time to interactive to batch, on uniprocessor and multiprocessor platforms. However, most schedulers either do not address latency requirements or are specialized to complex real-time paradigms, limiting their applicability to general-purpose systems.In this paper, we present Borrowed-Virtual-Time (BVT) Scheduling, showing that it provides low-latency for real-time and interactive applications yet weighted sharing of the CPU across applications according to system policy, even with thread failure at the real-time level, all with a low-overhead implementation on multiprocessors as well as uniprocessors. It makes minimal demands on application developers, and can be used with a reservation or admission control module for hard real-time applications.

l,oggged [Itrhra[ 71teruory ( LVM ) provides a log of writes to ol]e or more sImcified regions of the virtual address space.I,ogging is useflll for applications that, require rollback and/ur perslstjenre slich as parallel simulations and memory-mapped obje( t-oriented databases It can also }Je Ilsed for olltpllt,, de})nggmg and chstrihuted consistency maintenance.Tlus }japer describes logged virtual memory as an extensiou of the standard virtual memory system software and harxiwarr.our l,rotot,ype implementation and some perforrrance measurements from this prototype.Based on these measurements and the experience with our prototype, we arglle that logged virtual memory can be supported with moclest, extensions to standard virtual memory systems, provides significant benefit to applications and servers, and is faster than other log-generation technicples.