In 2001, our ISV Engineering group at Sun --f.k.a. Market Development Engineering-- released the first version
of the Hardware Activity Reporter (HAR) tool for Solaris 8 and up.
Starting with Solaris 8, Sun had begun to deliver public interfaces for
the SPARC and x86 hardware performance counters --libcpc, to access CPU counters and libpctx, to track a process--, leading to a new generation of performance monitoring tools: the Solaris cpustat and cputrack commands, hardware-counter profiling in Sun Studio's Performance Analyzer, SPOT and HAR, to name a few.
HAR differs from other tools in the fact that it combines the low-level counts into higher-level metrics more useful to application programmers. Application programmers are typically interested in the following metrics: CPI, FLOPS, MIPS, address bus percentage utilization, cache miss rates, branch and branch miss rates, and stall rates. These metrics help in assessing the fair usage of available processing units, locating bottlenecks and guiding tuning efforts, when needed. Check out this SDN article on how to use HAR to identify performance bottlenecks and quantify code-tuning improvements through a couple of case studies in the fields of CFD and MCAD.
Since the release of Solaris 10, HAR 1.x had become somewhat obsolete as we stopped adding support for new processors after UltraSPARC IV and Pentium P6. Today, thanks to the work of Amir Javanshir, we are happy to announce the release 2.0 of HAR, featuring…[Read More]


