Evaluation of the adaptation techniques in Kernel Tool Kit (KTK)

Our past research with configurable operating system abstractions has developed a model and implementation of adaptive multiprocessor operating systems for improved application performance. Adaptive locks are one such kernel component where lock adaptations are performed for each application program to suit its dynamic locking pattern. The paper compares and evaluates two different methods for performing such runtime adaptation: synchronous adaptations performed in conjunction with program accesses to the abstractions being configured and asynchronous adaptations performed concurrently with the program´s execution. Asynchronous and synchronous adaptation schemes are evaluated experimentally using adaptive locks for several multiprocessor applications on a KSR-2 supercomputer. Experiments establish that the attainment of performance gains by use of dynamic adaptation requires the use of both schemes, each suitable for different classes of application programs.