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236
Eraser: a dynamic data race detector for multithreaded programs
- ACM Transaction of Computer System
, 1997
"... Multi-threaded programming is difficult and error prone. It is easy to make a mistake in synchronization that produces a data race, yet it can be extremely hard to locate this mistake during debugging. This paper describes a new tool, called Eraser, for dynamically detecting data races in lock-based ..."
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Cited by 687 (2 self)
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Multi-threaded programming is difficult and error prone. It is easy to make a mistake in synchronization that produces a data race, yet it can be extremely hard to locate this mistake during debugging. This paper describes a new tool, called Eraser, for dynamically detecting data races in lock-based multi-threaded programs. Eraser uses binary rewriting techniques to monitor every shared memory reference and verify that consistent locking behavior is observed. We present several case studies, including undergraduate coursework and a multi-threaded Web search engine, that demonstrate the effectiveness of this approach. 1
Scope Consistency : A Bridge between Release Consistency and Entry Consistency
- In Proceedings of the 8th Annual ACM Symposium on Parallel Algorithms and Architectures
, 1996
"... The large granularity of communication and coherence in shared virtual memory systems causes problems with false sharing and extra communication. Relaxed memory consistency models have been used to alleviate these problems, but at a cost in programming complexity. Release Consistency (RC) and Lazy R ..."
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Cited by 169 (12 self)
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The large granularity of communication and coherence in shared virtual memory systems causes problems with false sharing and extra communication. Relaxed memory consistency models have been used to alleviate these problems, but at a cost in programming complexity. Release Consistency (RC) and Lazy Release Consistency (LRC) are accepted to offer a reasonable tradeoff between performance and programming complexity. Entry Consistency (EC) offers a more relaxed consistency model, but it requires explicit association of shared data objects with synchronization variables. The programming burden of providing such associations can be substantial. This paper proposes a new consistency model for shared virtual memory, called Scope Consistency (ScC), which offers most of the potential performance advantages of the EC model without requiring explicit bindings between data and synchronization variables. Instead, ScC dynamically detects the bindings implied by the programmer allowing a programming i...
Cashmere-2L: Software Coherent Shared Memory on a Clustered Remote-Write Network
- In Proceedings of the 16th ACM Symposium on Operating Systems Principles
, 1997
"... Low-latency remote-write networks, such as DEC’s Memory Channel, provide the possibility of transparent, inexpensive, large-scale shared-memory parallel computing on clusters of shared memory multiprocessors (SMPs). The challenge is to take advantage of hardware shared memory for sharing within an S ..."
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Cited by 132 (28 self)
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Low-latency remote-write networks, such as DEC’s Memory Channel, provide the possibility of transparent, inexpensive, large-scale shared-memory parallel computing on clusters of shared memory multiprocessors (SMPs). The challenge is to take advantage of hardware shared memory for sharing within an SMP, and to ensure that software overhead is incurred only when actively sharing data across SMPs in the cluster. In this paper, we describe a “twolevel” software coherent shared memory system—Cashmere-2L— that meets this challenge. Cashmere-2L uses hardware to share memory within a node, while exploiting the Memory Channel’s remote-write capabilities to implement “moderately lazy ” release consistency with multiple concurrent writers, directories, home nodes, and page-size coherence blocks across nodes. Cashmere-2L employs a novel coherence protocol that allows a high level of
Mondrian Memory Protection
, 2002
"... Mondrian memory protection (MMP) is a fine-grained protection scheme that allows multiple protection domains to flexibly share memory and export protected services. In contrast to earlier pagebased systems, MMP allows arbitrary permissions control at the granularity of individual words. We use a com ..."
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Cited by 122 (3 self)
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Mondrian memory protection (MMP) is a fine-grained protection scheme that allows multiple protection domains to flexibly share memory and export protected services. In contrast to earlier pagebased systems, MMP allows arbitrary permissions control at the granularity of individual words. We use a compressed permissions table to reduce space overheads and employ two levels of permissions caching to reduce run-time overheads. The protection tables in our implementation add less than 9% overhead to the memory space used by the application. Accessing the protection tables adds less than 8% additional memory references to the accesses made by the application. Although it can be layered on top of demandpaged virtual memory, MMP is also well-suited to embedded systems with a single physical address space. We extend MMP to support segment translation which allows a memory segment to appear at another location in the address space. We use this translation to implement zero-copy networking underneath the standard read system call interface, where packet payload fragments are connected together by the translation system to avoid data copying. This saves 52% of the memory references used by a traditional copying network stack.
CoreDet: A Compiler and Runtime System for Deterministic Multithreaded Execution
"... The behavior of a multithreaded program does not depend only on its inputs. Scheduling, memory reordering, timing, and low-level hardware effects all introduce nondeterminism in the execution of multithreaded programs. This severely complicates many tasks, including debugging, testing, and automatic ..."
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Cited by 104 (10 self)
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The behavior of a multithreaded program does not depend only on its inputs. Scheduling, memory reordering, timing, and low-level hardware effects all introduce nondeterminism in the execution of multithreaded programs. This severely complicates many tasks, including debugging, testing, and automatic replication. In this work, we avoid these complications by eliminating their root cause: we develop a compiler and runtime system that runs arbitrary multithreaded C/C++ POSIX Threads programs deterministically. A trivial non-performant approach to providing determinism is simply deterministically serializing execution. Instead, we present a compiler and runtime infrastructure that ensures determinism but resorts to serialization rarely, for handling interthread communication and synchronization. We develop two basic approaches, both of which are largely dynamic with performance improved by some static compiler optimizations. First, an ownership-based approach detects interthread communication via an evolving table that tracks ownership of memory regions by threads. Second, a buffering approach uses versioned memory and employs a deterministic commit protocol to make changes visible to other threads. While buffering has larger single-threaded overhead than ownership, it tends to scale better (serializing less often). A hybrid system sometimes performs and scales better than either approach individually. Our implementation is based on the LLVM compiler infrastructure. It needs neither programmer annotations nor special hardware. Our empirical evaluation uses the PARSEC and SPLASH2 benchmarks and shows that our approach scales comparably to nondeterministic execution.
Application Restructuring and Performance Portability on Shared Virtual Memory and Hardware-Coherent Multiprocessors
- In Proceedings of the 6th ACM Symposium on Principles and Practice of Parallel Programming
, 1997
"... The performance portability of parallel programs across a wide range of emerging coherent shared address space systems is not well understood. Programs that run well on efficient, hardware cache-coherent systems often do not perform well on less optimal or more commodity-based communication architec ..."
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Cited by 64 (17 self)
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The performance portability of parallel programs across a wide range of emerging coherent shared address space systems is not well understood. Programs that run well on efficient, hardware cache-coherent systems often do not perform well on less optimal or more commodity-based communication architectures. This paper studies this issue of performance portability, with the commodity communication architecture of interest being page-grained shared virtual memory. We begin with applications that perform well on moderate-scale hardware cache-coherent systems, and find that they do not do so well on SVM systems. Then, we examine whether and how the applications can be improved for SVM systems ---through data structuring or algorithmic enhancements---and the nature and difficulty of the optimizations. Finally, we examine the impact of the successful optimizations on hardware-coherent platforms themselves, to see whether they are helpful, harmful or neutral on those platforms. We develop a sys...
Performance Evaluation of the Orca Shared Object System
- ACM Transactions on Computer Systems
, 1998
"... Orca is a portable, object-based distributed shared memory system. This paper studies and evaluates the design choices made in the Orca system and compares Orca with other DSMs. The paper gives a quantitative analysis of Orca's coherence protocol (based on write-updates with function shipping), ..."
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Cited by 62 (42 self)
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Orca is a portable, object-based distributed shared memory system. This paper studies and evaluates the design choices made in the Orca system and compares Orca with other DSMs. The paper gives a quantitative analysis of Orca's coherence protocol (based on write-updates with function shipping), the totally-ordered group communication protocol, the strategy for object placement, and the all-software, user-space architecture. Performance measurements for ten parallel applications illustrate the tradeoffs made in the design of Orca, and also show that essentially the right design decisions have been made. A write-update protocol with function shipping is effective for Orca, especially since it is used in combination with techniques that avoid replicating objects that have a low read/write ratio. The overhead of totally-ordered group communication on application performance is low. The Orca system is able to make near-optimal decisions for object placement and replication. In addition, the...
OpenMP for Networks of SMPs
"... In this paper, we present the first system that implements OpenMP on a network of shared-memory multiprocessors. This system enables the programmer to rely on a single, standard, shared-memory API for parallelization within a multiprocessor and between multiprocessors. It is implemented via a transl ..."
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Cited by 57 (0 self)
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In this paper, we present the first system that implements OpenMP on a network of shared-memory multiprocessors. This system enables the programmer to rely on a single, standard, shared-memory API for parallelization within a multiprocessor and between multiprocessors. It is implemented via a translator that converts OpenMP directives to appropriate calls to a modified version of the TreadMarks software distributed memory system (SDSM). In contrast to previous SDSM systems for SMPs, the modified TreadMarks uses POSIX threads for parallelism within an SMP node. This approach greatly simplifies the changes required to the SDSM in order to exploit the intra-node hardware shared memory. We present performance results for six applications (SPLASH-2 Barnes-Hut and Water, NAS 3D-FFT, SOR, TSP and MGS) running on an SP2 with four four-processor SMP nodes. A comparison between the threaded implementation and the original implementation of TreadMarks shows that using the hardware shared memory within an SMP node significantly reduces the amount of data and the number of messages transmitted between nodes, and consequently achieves speedups up to 30 % better than the original versions. We also compare SDSM against message passing. Overall, the speedups of multithreaded TreadMarks programs are within 7–30 % of the MPI versions.
Home-based Shared Virtual Memory
, 1998
"... In this dissertation, I investigate how to improve the performance of shared virtual memory (SVM) by examining consistency models, protocols, hardware support and applications. The main conclusion of this research is that the performance of shared virtual memory can be significantly improved when pe ..."
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Cited by 54 (4 self)
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In this dissertation, I investigate how to improve the performance of shared virtual memory (SVM) by examining consistency models, protocols, hardware support and applications. The main conclusion of this research is that the performance of shared virtual memory can be significantly improved when performance-enhancing techniques from all these areas are combined. This dissertation proposes home-based lazy release consistency as a simple, effective, and scalable way to build shared virtual memory systems. In home-based protocols each shared page has a home to which all writes are propagated and from which all copies are derived. Two home-based protocols are described, implemented and evaluated on two hardware and software platforms: Automatic Update Release Consistency (AURC), which requires hardware support for fine-grained remote writes (automatic updates), and Homebased Lazy Release Consistency (HLRC), which is implemented exclusively in software. The dissertation investigates the ...
Temporal Notions of Synchronization and Consistency in Beehive
- In Proc. of the 9th Annual ACM Symp. on Parallel Algorithms and Architectures
, 1997
"... this paper are: ..."
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