Results 1 - 10
of
11
PLUM: Parallel Load Balancing for Adaptive Unstructured Meshes
, 1998
"... Mesh adaption is a powerful tool for efficient unstructured-grid computations but causes load imbalance among processors on a parallel machine. We present a novel method called PLUM to dynamically balance the processor workloads with a global view. This paper describes the implementation and integra ..."
Abstract
-
Cited by 46 (10 self)
- Add to MetaCart
(Show Context)
Mesh adaption is a powerful tool for efficient unstructured-grid computations but causes load imbalance among processors on a parallel machine. We present a novel method called PLUM to dynamically balance the processor workloads with a global view. This paper describes the implementation and integration of all major components within our dynamic load balancing strategy for adaptive grid calculations. Mesh adaption, repartitioning, processor assignment, and remapping are critical components of the framework that must be accomplished rapidly and efficiently so as not to cause a significant overhead to the numerical simulation. A data redistribution model is also presented that predicts the remapping cost on the SP2. This model is required to determine whether the gain from a balanced workload distribution offsets the cost of data movement. Results presented in this paper demonstrate that PLUM is an effective dynamic load balancing strategy which remains viable on a large number of processors.
A Hierarchical Partition Model for Adaptive Finite Element Computation
- Comput. Methods Appl. Mech. Engrg
, 1998
"... Introduction The finite element method (FEM) has become a standard analysis tool for solving partial differential equations (PDEs). Computationally demanding threedimensional problems make adaptive methods and parallel computation essential. Adaptive FEMs provide reliability, robustness, and time an ..."
Abstract
-
Cited by 27 (5 self)
- Add to MetaCart
(Show Context)
Introduction The finite element method (FEM) has become a standard analysis tool for solving partial differential equations (PDEs). Computationally demanding threedimensional problems make adaptive methods and parallel computation essential. Adaptive FEMs provide reliability, robustness, and time and space efficiency. In such a method, the computational domain is discretized into a mesh. During the adaptive solution process, portions of the mesh may be refined or coarsened (h-refinement) or moved to follow evolving phenomena (r-refinement). The method order may also be varied (p-refinement). Each adaptive process concentrates the computational effort in areas where the solution resolution would otherwise be inadequate [7]. Conventional array-based data representations, which work well for fixed-mesh solutions, are not wellsuited to solutions involving mesh adaptivity [1]. Traversal of the data must be efficient in all cases, but w
Load Balancing Unstructured Adaptive Grids for CFD Problems
- 8TH IEEE SYMPOSIUM ON PARALLEL AND DISTRIBUTED PROCESSING
, 1997
"... Mesh adaption is a powerful tool for efficient unstructured-grid computations but causes load imbalance among processors on a parallel machine. A dynamic load balancing method is presented that balances the workload across all processors with a global view. After each parallel tetrahedral mesh ad ..."
Abstract
-
Cited by 18 (5 self)
- Add to MetaCart
Mesh adaption is a powerful tool for efficient unstructured-grid computations but causes load imbalance among processors on a parallel machine. A dynamic load balancing method is presented that balances the workload across all processors with a global view. After each parallel tetrahedral mesh adaption, the method first determines if the new mesh is sufficiently unbalanced to warrant a repartitioning. If so, the adapted mesh is repartitioned, with new partitions assigned to processors so that the redistribution cost is minimized. The new partitions are accepted only if the remapping cost is compensated by the improved load balance. Results indicate that this strategy is effective for large-scale scientific computations on distributed-memory multiprocessors.
Efficient Load Balancing and Data Remapping for Adaptive Grid Calculations
- 9TH ACM SYMPOSIUM ON PARALLEL ALGORITHMS AND ARCHITECTURES
, 1997
"... Mesh adaption is a powerful tool for efficient unstructured grid computations but causes load imbalance among processors on a parallel machine. We present a novel method to dynamically balance the processor workloads with a global view. This paper presents, for the first time, the implementation and ..."
Abstract
-
Cited by 16 (6 self)
- Add to MetaCart
(Show Context)
Mesh adaption is a powerful tool for efficient unstructured grid computations but causes load imbalance among processors on a parallel machine. We present a novel method to dynamically balance the processor workloads with a global view. This paper presents, for the first time, the implementation and integration of all major components within our dynamic load balancing strategy for adaptive grid calculations. Mesh adaption, repartitioning, processor assignment, and remapping are critical components of the framework that must be accomplished rapidly and efficiently so as not to cause a significant overhead to the numerical simulation. Previous results indicated that mesh repartitioning and data remapping are potential bottlenecks for performing large-scale scientific calculations. We resolve these issues and demonstrate that our framework remains viable on a large number of processors.
DRAMA: A Library for Parallel Dynamic Load Balancing of Finite Element Applications
- In Ninth SIAM Conference on Parallel Processing for Scientific Computing
, 1999
"... We describe a software library for dynamic load balancing of finite element codes at run-time. The application code has to provide the current distributed mesh and information on the calculation and communication requirements, and receives from the library all necessary information to re-allocate th ..."
Abstract
-
Cited by 16 (3 self)
- Add to MetaCart
We describe a software library for dynamic load balancing of finite element codes at run-time. The application code has to provide the current distributed mesh and information on the calculation and communication requirements, and receives from the library all necessary information to re-allocate the application data. The library computes a new partitioning, either via direct mesh migration or via parallel graph re-partitioning, by interfacing to the ParMetis package. In this paper, we discuss the underlying cost model and the various graph representations of the cost model that are implemented in the library. We describe the functionality of the DRAMA library and we present some first results. 1 Introduction Parallel finite element applications can have changing work load and communication requirements, due to re-meshing, adaptive mesh refinement (and de-refinement), or due to a changing calculation or communication cost in parts of the mesh. In these cases, dynamic load balancing ca...
Experiments with Repartitioning and Load Balancing Adaptive Meshes
, 1997
"... . Mesh adaption is a powerful tool for efficient unstructured-grid computations but causes load imbalance on multiprocessor systems. To address this problem, we have developed PLUM, an automatic portable framework for performing adaptive largescale numerical computations in a message-passing environ ..."
Abstract
-
Cited by 15 (7 self)
- Add to MetaCart
. Mesh adaption is a powerful tool for efficient unstructured-grid computations but causes load imbalance on multiprocessor systems. To address this problem, we have developed PLUM, an automatic portable framework for performing adaptive largescale numerical computations in a message-passing environment. This paper presents several experimental results that verify the effectiveness of PLUM on sequences of dynamically adapted unstructured grids. We examine portability by comparing results between the distributed-memory system of the IBM SP2, and the Scalable Shared-memory MultiProcessing (S2MP) architecture of the SGI/Cray Origin2000. Additionally, we evaluate the performance of five state-of-the-art partitioning algorithms that can be used within PLUM. Results indicate that for certain classes of unsteady adaption, globally repartitioning the computational mesh produces higher quality results than diffusive repartitioning schemes. We also demonstrate that a coarse starting mesh produce...
Load Balancing Sequences of Unstructured Adaptive Grids
- 4TH INTERNATIONAL CONFERENCE ON HIGH PERFORMANCE COMPUTING
, 1997
"... Mesh adaption is a powerful tool for efficient unstructured grid computations but causes load imbalance on multiprocessor systems. To address this problem, we have developed PLUM, an automatic portable framework for performing adaptive large-scale numerical computations in a message-passing environm ..."
Abstract
-
Cited by 3 (3 self)
- Add to MetaCart
Mesh adaption is a powerful tool for efficient unstructured grid computations but causes load imbalance on multiprocessor systems. To address this problem, we have developed PLUM, an automatic portable framework for performing adaptive large-scale numerical computations in a message-passing environment. This paper makes several important additions to our previous work. First, a new remapping cost model is presented and empirically validated on an SP2. Next, our load balancing strategy is applied to sequences of dynamically adapted unstructured grids. Results indicate that our framework is effective on many processors for both steady and unsteady problems with several levels of adaption. Additionally, we demonstrate that a coarse starting mesh produces high quality load balancing, at a fraction of the cost required for a fine initial mesh. Finally, we show that the data remapping overhead can be significantly reduced by applying our heuristic processor reassignment algorithm.
Topology Preserving Dynamic Load Balancing for Parallel Molecular Simulations
- In Proceedings of Supercomputing '97
, 1997
"... this paper we focus on the analysis and performance of one such algorithm, Positional Scan Load Balancing, and its suitability for use in the runtime system of the parallel simulation environment. 2 Problem Model, Description and Decomposition ..."
Abstract
-
Cited by 2 (0 self)
- Add to MetaCart
(Show Context)
this paper we focus on the analysis and performance of one such algorithm, Positional Scan Load Balancing, and its suitability for use in the runtime system of the parallel simulation environment. 2 Problem Model, Description and Decomposition
PLUM: Parallel Load Balancing for Unstructured Adaptive Meshes
, 1998
"... Dynamic mesh adaption on unstructured grids is a powerful tool for com-puting large-scale problems that require grid modifications to efficiently resolve so-lution features. Unfortunately, an efficient parallel implementation is difficult to achieve, primarily due to the load imbalance created by t ..."
Abstract
- Add to MetaCart
Dynamic mesh adaption on unstructured grids is a powerful tool for com-puting large-scale problems that require grid modifications to efficiently resolve so-lution features. Unfortunately, an efficient parallel implementation is difficult to achieve, primarily due to the load imbalance created by the dynamically-changing nonuniform grid. To address this problem, we have developed PLUM, an automatic portable framework for performing adaptive large-scale numerical computations in a message-passing environment. First, we present an efficient parallel implementation of a tetrahedral mesh adaption scheme. Extremely promising parallel performance is achieved for various refinement and coarsening strategies on a reaiistic-sized domain. Next we describe PLUM, a novel method for dynamically balancing the processor workloads in adap-tive grid computations. This research includes interfacing the parallel mesh adaption procedure based on actual flow solutions to a data remapping module, and incor-porating an efficient parallel mesh repartitioner. A significant runtime improvement
by
, 1998
"... Dynamicmeshadaptionon unstructured grids is a powerful tool for com-puting large-scale problems that require grid modifications to efficiently resolve so-lution features. Unfortunately, an efficient parallel implementation is difficult to achieve, primarily due to the load imbalance created by the d ..."
Abstract
- Add to MetaCart
Dynamicmeshadaptionon unstructured grids is a powerful tool for com-puting large-scale problems that require grid modifications to efficiently resolve so-lution features. Unfortunately, an efficient parallel implementation is difficult to achieve, primarily due to the load imbalance created by the dynamically-changing nonuniform grid. To address this problem, we have developed PLUM, an automatic portable framework for performing adaptive large-scale numerical computations in a message-passing environment. First, we present an efficient parallel implementation of a tetrahedral mesh adaption scheme. Extremely promising parallel performance is achieved for various refinement and coarsening strategies on a realistic-sized domain. Next we describe PLUM, a novel method for dynamically balancing the processor workloads in adap-tive grid computations. This research includes interfacing the parallel mesh adaption procedure based on actual flow solutions to a data remapping module, and incor-porating an efficient parallel mesh repartitioner. A significant runtime improvement is achieved by observing that data movement for a refinement step should be per-
