This tutorial shows how to use Performance Analyzer on a multithreaded program named mttest to collect and understand clock profiling and hardware counter profiling data.
You explore the Overview page and change which metrics are shown, examine the Functions view, Callers-Callees view, and Source and Disassembly views, and apply filters.
You first explore the clock profile data, then the HW-counter profile data with Instructions Executed which is a counter available on all supported systems. Then you explore Instructions Executed and CPU Cycles (available on most, but not all, supported systems) and with D-cache Misses (available on some supported systems).
If run on a system with a precise hardware counter for D-cache Misses (dcm), you will also learn how to use the IndexObject and MemoryObject views, and how to detect false sharing of a cache line.
The program mttest is a simple program that exercises various synchronization options on dummy data. The program implements a number of different tasks and each task uses a basic algorithm:
Queue up a number of work blocks, four by default. Each one is an instance of a structure Workblk.
Spawn a number of threads to process the work, also four by default. Each thread is passed its private work block.
In each task, use a particular synchronization primitive to control access to the work blocks.
Process the work for the block, after the synchronization.
The data you see in the experiment that you record will be different from that shown here. The experiment used for the screen shots in the tutorial was recorded on a SPARC T5 system running Oracle Solaris 11.3. The data from an x86 system running Oracle Solaris or Linux will be different. Furthermore, data collection is statistical in nature and varies from experiment to experiment, even when run on the same system and OS.
The Performance Analyzer window configuration that you see might not precisely match the screen shots. Performance Analyzer enables you to drag separator bars between components of the window, collapse components, and resize the window. Performance Analyzer records its configuration and uses the same configuration the next time it runs. Many configuration changes were made in the course of capturing the screen shots shown in the tutorial.