Parallel Computing

This page lists available online tutorials related to parallel programming and using LC's HPC systems.

Optimizing parallel codes is becoming increasingly important to ensure those codes run efficiently on modern and future HPC machines. To aid in this, LLNL will be hosting a workshop on optimizing code using the TAU Performance System, on Livermore Computing HPC systems for HPC code developers and users. In this training, we will have the TAU principal developer, Dr. Sameer Shende of ParaTools, Inc., onsite to provide free instruction and consultation. Introductory sessions will cover the basics of using TAU and advanced topics will be covered to further participants ability to use TAU. The workshop will include sample codes that illustrate the different instrumentation and measurement choices available and will be leveraged in hands-on sessions designed to guide participants through TAU's capabilities. One-on-one consultation sessions are available for further, more in-depth, instruction and help in addressing performance bottlenecks in your codes. Those already familiar with TAU are more than welcome to participate in any session.

Both Slurm and IBM's CSM provide a way to launch tasks (aka, Linux processes) of a user's application in parallel across resources allocated to the job. For Slurm, the command is srun; for CSM, the command is jsrun. This page presents their similarities and their differences. It also details lrun, an LLNL developed wrapper script for jsrun.

Since 1998, Software Carpentry has been teaching researchers the computing skills they need to get more done in less time and with less pain. The lessons teach basic lab skills for research computing and lessons are developed collaboratively in GitHub.

To meet the needs of computational scientists to evaluate the performance of their parallel, scientific applications, we present the TAU Performance System and its interfaces to other tools such as PAPI, Score-P, Scalasca, OTF and Vampir. This one day workshop will cover performance evaluation of applications on Tri-lab OCF platforms. This workshop will focus on performance data collection, analysis, and performance optimization.

This workshop is intended for code teams and developers who will be using LLNL's future CORAL Sierra supercomputer. In preparation for Sierra, LC provides Early Access (EA) systems using a similar hardware and software environment. The focus of this introductory workshop is to provide basic "getting started" information for prospective users of these EA systems. Materials presented include Sierra overview, EA hardware, accounts/access, selected user environment topics, compilers, MPI, running jobs & the LSF scheduler, NVIDIA GPU topics, tools & debuggers, documentation and getting help.