Advanced Computing Technology Center © 2005 IBM Corporation The IBM High Performance Computing Toolkit Guojing Cong

Advanced Computing Technology Center © 2005 IBM Corporation IBM High Performance Computing Toolkit (HPCT)  One consolidated package  Components: –Hardware Performance Monitor(HPM) –Simulation Guided Memory Analyzer (SiGMA) –MPI Profiler (MP_profiler) –OpenMP Profiler (PompProf) –Modular I/O Performance Tool (MIO) –Xprofiler –GUI integration tool w/ source code traceback (PeekPerf) –Watson Sparse Matrix Library (WSMP) included

Advanced Computing Technology Center © 2005 IBM Corporation Our Vision  A toolkit that spans various aspects of high performance computing –CPU profiling, memory behavior analysis, communication profiling, I/O analysis and optimization  Integrated performance monitoring and profiling environment – one single consistent interface for all components – enhanced functionality Binary instrumentation (without source code modification) Dynamic instrumentation  Available on IBM Platforms –AIX, LoP, and BlueGene

Advanced Computing Technology Center © 2005 IBM Corporation Support Matrix HPMCount & HPMlib MP- profiler& MP-tracer Xprofiler SHMEM & SHMEM- profiler MIO PompPofi ler SiGMA PeekPerf Watson Sparse Matrix Package AIX Powe r today (AIX 5L 5.1, 5.3) today (AIX ) today (AIX 5L 5.1) today (AIX ) today (AIX 5L 5.1) Linux Powe r Aug/05 (Linux 2.4 &2.6) May/05 (Linux 2.6) Aug-Sep/05 (Linux 2.6) N/A TBT (Linux 2.6) N/A Aug-Sep/05 (Linux 2.6) TBTTBT(Linux 2.6) Linux JS20 Aug/05 (Linux 2.4 &2.6) May/05 (Linux 2.6) Aug-Sep/05 (Linux 2.6) N/A TBT (Linux 2.6) N/A Aug-Sep/05 (Linux 2.6) TBTTBT(Linux 2.6) Linux BG/L Aug/05todayAug/05N/ATBTN/A todayN/A

Advanced Computing Technology Center © 2005 IBM Corporation Outline  Xprofiler  HPM  MP Profiler  OpenMP Profiler  MIO

Advanced Computing Technology Center © 2005 IBM Corporation Xprofiler  CPU profiling tool similar to gprof  Can be used to profile both serial and parallel applications  Use procedure-profiling information to construct a graphical display of the functions within an application  Provide quick access to the profiled data and helps users identify functions that are the most CPU-intensive  Based on sampling (support from both compiler and kernel)  Charge execution time to source lines and show disassembly code

Advanced Computing Technology Center © 2005 IBM Corporation Xprofiler: Main Display  Width of a bar: time including called routines  Height of a bar: time excluding called routines  Call arrows labeled with number of calls  Overview window for easy navigation (View  Overview)

Advanced Computing Technology Center © 2005 IBM Corporation Xprofiler: Source Code Window  Source code window displays source code with time profile (in ticks=.01 sec)  Access –Select function in main display –  context menu –Select function in flat profile –  Code Display –  Show Source Code

Advanced Computing Technology Center © 2005 IBM Corporation Xprofiler - Disassembler Code

Advanced Computing Technology Center © 2005 IBM Corporation HPM  provides comprehensive reports of hardware events that are critical to performance –Accurate and Low overhead –Comprehensive E.g., number of floating-point instructions executed, cache misses, TLB misses  Derived metrics –correlate the behavior of the application to one or more of the hardware components  Thread-level support  Including –Hpmcount, libhpm, hpmstat

Advanced Computing Technology Center © 2005 IBM Corporation HPM Visualization Using PeekPerf

Advanced Computing Technology Center © 2005 IBM Corporation MP_profiler  A set of libraries that collect profiling data for MPI and TurboSHMEM applications –Implements wrappers using PMPI interface  Report performance metrics, e.g., –time used by MPI function calls –message sizes  Visualization tools help users identify performance bottlenecks –peekperf maps performance metrics back to the source codes –peekview gives a visual representation of the overall computation and communication pattern of the system.

Advanced Computing Technology Center © 2005 IBM Corporation MP_Profiler Visualization Using PeekPerf

Advanced Computing Technology Center © 2005 IBM Corporation MP_Tracer Visualization Using PeekPerf

Advanced Computing Technology Center © 2005 IBM Corporation POMP Profiler (PompProf)  Generates a detailed profile describing overheads and time spent by each thread in three key regions of the parallel application: –Parallel regions –OpenMP loops inside a parallel region –User defined functions  Profile data is presented in the form of an XML file that can be visualized with PeekPerf

Advanced Computing Technology Center © 2005 IBM Corporation DPOMP  Dynamically instruments OpenMP applications  Has the advantage of the being able to modify binaries with performance instrumentation without requiring access to souce codes or recompilation  Based on dynamic probes using DPCL

Advanced Computing Technology Center © 2005 IBM Corporation PompProf Visualization Using PeekPerf

Advanced Computing Technology Center © 2005 IBM Corporation Modular I/O Performance Tool (MIO)  I/O Analysis –Trace module –Summary of File I/O Activity + Binary Events File –Low CPU overhead  I/O Performance Enhancement Library –Prefetch module (optimizes asynchronous prefetch and write-behind) –System Buffer Bypass capability –User controlled pages (size and number)  Recoverable Error Handling –Recover module (monitors return values and errnor + reissues failed requests)  Remote Data Server –Remote module (simple socket protocol for moving data)  Shared object library for AIX

Advanced Computing Technology Center © 2005 IBM Corporation MIO User Code Interface #define open64(a,b,c)MIO_open64(a,b,c,0) #define readMIO_read #define writeMIO_write #define closeMIO_close #define lseek64MIO_lseek64 #define fcntlMIO_fcntl #define ftruncate64MIO_ftruncate64 #define fstat64MIO_fstat64

Advanced Computing Technology Center © 2005 IBM Corporation MIO Trace Module (sample partial text output) Trace close : program pf : /bmwfs/cdh108.T20536_13.SCR300 : (281946/ )= mbytes/s current size=0 max_size=16277 mode =0777 sector size=4096 oflags =0x302=RDWR CREAT TRUNC open write read seek fcntl trunc close size

Advanced Computing Technology Center © 2005 IBM Corporation MSC.Nastran V2001 Benchmark: SOL 111, 1.7M DOF, 1578 modes, 146 frequencies, residual flexibility and acoustics. 120 GB of disk space. Machine: 4-way, 1.3 GHz p655, 32 GB with 16 GB large pages, JFS striped on 16 SCSI disks. MSC.Nastran: V with large pages, dmp=2 parallel=2 mem=700mb The run with MIO used mio=1000mb Time (seconds) 6.8 TB of I/O in seconds is an average of about 250 MB/sec 0 10,000 20,000 30,000 40,000 50,000 60,000 no MIOwith MIO Elapsed CPU time

Advanced Computing Technology Center © 2005 IBM Corporation

Advanced Computing Technology Center © 2005 IBM Corporation

Advanced Computing Technology Center © 2005 IBM Corporation Problems that we are considering  Performance profiling and monitoring for scientific applications on large systems –Selectively generates and reports profiling data –Large amount performance data management and analysis  Composite profiling and presentation –CPU profiling –Hardware Performance Counter profiling –Communication profiling