1,184 papers · page 49 of 60
Since APL, reductions and scans have been recognized as powerful programming concepts. Abstracting an accumulation loop (reduction) and an update loop (scan), the concepts have efficient parallel implementations based on the parallel prefix algorithm. They are often included in h…
Utility computing is becoming a popular way of exploiting the potential of computational grids. In utility computing, users are provided with computational power in a transparent manner similar to the way in which electrical utilities supply power to their customers. To take full…
IP forwarding is one of the main bottlenecks in Internet backbone routers, as it requires performing the longest-prefix match at 10Gbps speed or higher. IPv6 forwarding further exacerbates the situation because its search space is quadrupled. We propose a high-performance IPv6 fo…
Processor virtualization via migratable objects is a powerful technique that enables the runtime system to carry out intelligent adaptive optimizations like dynamic resource management. CHARM++ is an early language/system that supports migratable objects. This paper describes Ada…
In 2002, we first brought High Performance Computing (HPC) methods to the college classroom as a way to enrich Computational Science education. Through the years, we have continued to facilitate college faculty in science, technology, engineering, and mathematics (STEM) disciplin…
While the high-performance computing world is dominated by distributed memory computer systems, applications that require random access into large shared data structures continue to motivate development of ever larger shared-memory parallel computers such as Cray's MTA and SGI's …
High performance parallel programs are currently difficult to write and debug. One major source of difficulty is protecting concurrent accesses to shared data with an appropriate synchronization mechanism. Locks are the most common mechanism but they have a number of disadvantage…
As multi-core architectures with Thread-Level Speculation (TLS) are becoming better understood, it is important to focus on TLS compilation. TLS compilers are interesting in that, while they do not need to fully prove the independence of concurrent tasks, they make choices of whe…
We investigate a transactional memory runtime system providing scaling and strong consistency, i.e., 1-copy serializability on commodity clusters for both distributed scientific applications and database applications. We introduce a novel page-level distributed concurrency contro…
Cache coherent non-uniform memory architectures (ccNUMA) constitute an important class of high-performance computing plat-forms. Contemporary ccNUMA systems, such as the SGI Altix, have a large number of nodes, where each node consists of a small number of processors and a fixed …
Performance analysis tools are critical for the effective use of large parallel computing resources, but existing tools have failed to address three problems that limit their scalability: (1) management and processing of the volume of performance data generated when monitoring a …
Applications need to become more concurrent to take advantage of the increased computational power provided by chip level multiprocessing. Programmers have traditionally managed this concurrency using locks (mutex based synchronization). Unfortunately, lock based synchronization …
We present two new nonblocking and contention-free implementations of synchronous queues ,concurrent transfer channels in which producers wait for consumers just as consumers wait for producers. Our implementations extend our previous work in dual queues and dual stacks to effect…
This work presents a general methodology for estimating the performance of an HPC workload when running on a future hardware architecture. Further, it demonstrates the methodology by estimating the performance of a significant scientific application -- the Gyrokinetic Toroidal Co…
Recently, the high-performance computing community has realized that power is a performance-limiting factor. One reason for this is that supercomputing centers have limited power capacity and machines are starting to hit that limit. In addition, the cost of energy has become incr…
When a Search Engine responds to your query, thousands of machines from around the world have cooperated to produce your result. With a global reach of hundreds-of-millions of users, Search Engines are arguably the most commonly used massively-parallel computing systems on the pl…
As part of the DARPA program for High Productivity Computing Systems, the Programming Language Research Group at Sun Microsystems Laboratories is developing Fortress, a language intended to support large-scale scientific computation with the same level of portability that the Jav…
Message Passing Interface (MPI) is a popular parallel programming model for scientific applications. Most high-performance MPI implementations use Rendezvous Protocol for efficient transfer of large messages. This protocol can be designed using either RDMA Write or RDMA Read. Usu…
We study a family of implementations for linked lists using fine-grain synchronisation. This approach enables greater concurrency, but correctness is a greater challenge than for classical, coarse-grain synchronisation. Our examples are demonstrative of common design patterns suc…
Atomicity is an important correctness condition for concurrent systems. Informally, atomicity is the property that every concurrent execution of a set of transactions is equivalent to some serial execution of the same transactions. In multi-threaded programs, executions of proced…