Instruction-based sampling (IBS) is a statistical profiling method developed by AMD and has been available in AMD processors since 2007. This technique features the data collection of the two event types, IBS Fetch and IBS Op. These two classes of events provide various metrics related to the front- and back-end of the pipeline. In contrast to the Intel PEBS solution with configurable programmable counters, IBS cannot choose specific metrics usually available with hardware performance counters. IBS is implemented in the profiling interface perf event. Perf event is part of the Linux kernel since version 2.6 and developed in cooperation with hardware vendors in order to use functionalities related to the performance monitoring unit (PMU) of the processor. Perf event provides the system call perf event open() with the purpose of making performance metrics accessible to other profiling tools. One such tool is Mitos, which has been under development at the Lawrence Livermore National Laboratory and is now modified with new features at the Chair of Computer Architecture and Parallel Systems. This work implements the data collection functionality utilizing IBS in Mitos. It takes a closer look at the capabilities of perf event with IBS, various implementation aspects, and how IBS is usable in MPI and OpenMP applications. Currently, IBS requires system-wide data collection privileges and does not support per-process monitoring. Due to the missing per-process monitoring option, monitoring all processor cores individually and filtering event samples on a higher level might be a suitable workaround method. The other workaround idea only observes processor cores executing the target application and automatically moves with the target process on change detection. However, the detection implementation has performance-related issues and requires further modifications.     «

Instruction-based sampling (IBS) is a statistical profiling method developed by AMD and has been available in AMD processors since 2007. This technique features the data collection of the two event types, IBS Fetch and IBS Op. These two classes of events provide various metrics related to the front- and back-end of the pipeline. In contrast to the Intel PEBS solution with configurable programmable counters, IBS cannot choose specific metrics usually available with hardware performance counters....     »