文档介绍：PAPI on Blue Gene L work performance counters to layout tasks for improved performance Presentation overview ? Project objectives ? PAPI explanation ? Blue Gene L explanation ? Current state of research Project objectives ? Upgrade PAPI on BG/L ? Provide interface work counters ? Allow Lawrence Livermore National Lab users to also have access to PAPI ? work counters to place tasks optimally on BG/L PAPI – Intro Courtesy of http:// / PAPI – Intro ? PAPI useful to profile your own programs. ? Many tools based on PAPI ? PapiEx – Command line measurement tool ? PerfSuite – Aggregate measurement and statistical profiling package and API ? HPCToolkit – Statistical profiling package ? Many more! PAPI – Supported platforms ? IBM – POWER3, 604, 604e, POWER4 ? Cray T3E, Cray X1 ? AMD – Athlon , Opteron ? Intel – P1 to P4, Itanium I and II ? UltraSparc I, II & III ? MIPS R10K, R12K, R14K ? Alpha PAPI – Generic Interface ? Call sequence for generic interface ? PAPI_library_init – Initialize memory for PAPI ’s data structures ? PAPI_create_eventset – Create an empty list of events ? PAPI_add_event – Add events to be counted ? PAPI_start – Begin counting all events within the specified eventset ? PAPI_stop – Stop all counters and read their current values PAPI – Events: Presets ? Presets – list of predefined events implemented on all systems where they can be supported ? Not all presets available on every architecture (. BG/L has no cache lower than L3 – thus L1 cache hit preset not applicable) ? Native events form the basic building blocks for PAPI presets PAPI – Events: Presets Courtesy of http:// / PAPI – Events: Native ? In addition to the predefined PAPI preset events, the PAPI library also exposes a majority of the events native to each platform ? Can be added to eventsets in the same manner as presets