Staff Notes Daily Announcements

Optimizing Compilers for High-Performance Computing
Dr. Louis-Noël Pouchet
Assistant Professor, Colorado State University

Applications running on clusters of shared-memory computers are often implemented using OpenMP+MPI. Productivity can be vastly improved using task-based programming, a paradigm where the user expresses the data and control-flow relations between tasks, offering the runtime maximal freedom to place and schedule tasks. While productivity is increased, high-performance execution remains challenging: the implementation of parallel algorithms typically requires specific task placement and communication strategies to reduce inter-node communications and exploit data locality. Furthermore, pattern-specific and target-specific code optimizations are often needed to achieve high-performance execution of task bodies.

In this talk we present a new macro-dataflow programming environment for distributed-memory clusters, based on the Intel Concurrent Collections (CnC) runtime. Our language extensions let the user define virtual topologies, task mappings, task-centric data placement, task and communication scheduling, etc. We introduce a compiler to automatically generate Intel CnC C++ run-time, with key automatic optimizations including task coarsening and coalescing. We also present several pattern-specific optimization scenarios, including our latest results on optimizing stencil computations on regular grids.

Bio:

Dr. Louis-Noel Pouchet is an Assistant Professor at Colorado State University. He is working on pattern-specific languages and compilers for scientific computing, and has designed numerous approaches using optimizing compilation to effectively map applications to CPUs, FPGAs and SoCs.  His work spans a variety of domains, including compiler optimization, hardware synthesis, machine learning, programming languages, and distributed computing. His research is currently funded by the National Science Foundation, the Department of Energy, and Intel.  Previously he has been a Visiting Assistant Professor (2012-2014) at the University of California Los Angeles, where he was a member of the NSF Center for Domain-Specific Computing, working on both software and hardware customization. He is the author of the PolyOpt and PoCC compilers, and of the PolyBench/C benchmarking suite.

Thursday, September 29, 2016
10:00 – 11:00 am
NCAR Mesa Lab, Main Seminar Room

Heavy and persistent precipitation in a quasi­stationary convective system in SW England

 Alan Blyth

National Centre for Atmospheric Science, University of Leeds.

Observations were made with three aircraft, a ground­based X­band radar and several other ground­based instruments during the COnvective Precipitation Experiment (COPE) in the southwest peninsula of England during the summer of 2013.  Convergence lines form in the region as a result of colliding sea­breeze fronts.  Convective clouds often develop along the lines that occasionally results in flash flooding. The most infamous recent example occurred in Boscastle in August 2004. The flash floods and convergence lines have been studied using models and the UK Met Office (MO) network radars and rain gauges, but observations of the microphysics and dynamics of the systems were never made until COPE.

Modelling results and observations will be presented in this talk of a quasi­stationary convective system on 3 August 2013 that had some similarities to the Boscastle case. Heavy precipitation persisted for several hours in localised regions, although a flash flood did not occur. The measurements on this day were made with two aircraft (University of Wyoming King Air and UK BAe 146), a mobile radar, the MO network of radars and ground­based aerosol instruments.  The mobile radar is a dual­polarisation Doppler X­band radar. It made PPIs with a volume return time of about 5 minutes.  The WRF model run at 400­m resolution and a detailed microphysics model were used to help interpret the observations. The warm rain process, supercooled raindrops, graupel and multiple thermals appear to be key to the intensity and persistence of the precipitation

 Seminar will be webcast at: http://www.fin.ucar.edu/it/mms/fl2­live.htm

 Thursday, 29 September 2016, 3:30 PM

Refreshments 3:15 PM

NCAR­ Foothills Laboratory

3450 Mitchell Lane

Bldg 2 Small Seminar Room  (1001) 

Please join us for meet and greet session with UCAR President Tony Busalacchi on Tuesday, September 27 from 9:30-10:30 a.m. in the Mesa Lab Main Seminar Room. All staff are welcome to attend. This is an opportunity for you to meet Tony, hear about his background, and learn about his initial impressions as UCAR President.

Mark your calendars for UCAR's 2016 Free Onsite Seasonal Flu Vaccination Clinics, offered through Passport Health. This event is open to UCAR employees, their spouses/partners and dependent (adult) children 18-26 years of age and retirees. For dependent children under 18 years of age, please consult their healthcare provider(s) for these services.

Seasonal flu vaccinations are free to eligible participants. For questions on whether the vaccine is appropriate for you or a family member, please contact your healthcare provider.   Please note that Flumist is not available for the 2016-2017 flu season.  The traditional trivalent flu vaccine will be available onsite this year.  It offers protection against three flu viruses that are expected to circulate throughout the flu season.

2016 Onsite/Walk-in Flu Vaccination Clinics Schedule (No registration or vouchers required): 

• NWSC – Janice Conference Room   Wednesday, October 12, 10:00-11:30 am
• FL2-1003                                             Thursday, October 13,  9:00-11:30 am
• CG1-2503                                           Thursday, October 20,  9:00-11:30 am
• RAF/RMAA – Conference Room      Thursday, October 27, 10-11:30 am
• ML – Director’s Conference Room    Thursday, November 3, 9:00-11:30 am

Vouchers: Eligible participants who cannot attend any of the on-site clinics can schedule an appointment for the seasonal flu vaccination at any of the Passport Health Facilities listed below. UCAR employees visiting the Boulder Passport Health location must show their employee ID/access card.  No voucher is needed for the Boulder Passport Health location. Vouchers are required for all other eligible participants and for everyone visiting any other Passport Health location listed below. Vouchers are ONLY valid at these select Passport Health locations and can be redeemed any time between October 1 - December 31, 2016 (or while supplies last).  For more information or to request a voucher, contact Annette Lampert, x8719.

Please visit this link to view other available Passport Health facilities.

If there is not a scheduled event in your area OR you miss the scheduled Flu Shot Event in your location and there is no local Passport Health location, flu vaccines are available through all UCAR health insurance plans as preventive care and paid at 100%.

This event is offered as a service and participation is voluntary. UCAR does not endorse or recommend any product or service associated with this event.