We propose gpu localtm, a hardware transactional memory tm, as an alternative to data locking mechanisms in local memory. Evaluation of amds advanced synchronization facility within a complete transactional memory stack performance evaluation of intel transactional synchronization extensions for highperformance computing software transactional memory. Systemwide data consistency issues can be handled by a gpu friendly design of software transactional memory. Nilanjan goswami gpu architect advanced computing lab. Hardware support for local memory transactions on gpu. To improve gpus programmability and thus extend their usage to a wider range of applications, the authors propose to enable transactional memory tm on gpus. Ennals, efficient software transactional memory, technical report, intel research cambridge, uk, 2005. The ability of the gpu to handle considerably more threads than the cpu has recently led to increased interest in utilising transactional memory for gpu. In this paper, we analyze the performance and energy ef. If this mechanism is required very often it may harm performance. The unconverted parts of the java program could use up the cpu multicore resources with its multithreaded workload. Improvements in hardware transactional memory for gpu. Software transactional memory for gpu architectures yunlong xu.
A stm system that supports perthread transactions faces new challenges. Hardware support for scratchpad memory transactions on gpu. A question that arises in our smart highways use case is this. His research interests include parallel programming, software transactional memory, and distributed architectures. Software transactional memory provides transactional memory semantics in a software runtime library or the programming language, and requires minimal hardware support typically an atomic compare and swap operation, or equivalent. While transactional memory for processors with hundreds of cores is likely to require hardware support, software implementations will be required for backward compatibility with current and near. Gpustm, a software tm for gpus enables simplified data synchronizations on gpus scales to s of txs ensures livelockfreedom runs on commercially available gpus and runtime outperforms gpu coarsegrain locks by up to 20x. Yunlong xu, rui wang, nilanjan goswami, tao li and depei qian. There are three ways to copy data to the gpu memory, either implicitly through calresmapcalresunmap or explicitly via calctxmemcopy or via a custom copy shader that reads from pcie memory and writes to gpu memory. Pdf modern gpus have shown promising results in accelerating computation intensive and numerical workloads with limited dynamic data sharing. Scheduling techniques for gpu architectures with processing. A cuda program starts on a cpu and then launches parallel compute kernels onto a gpu. To appear in the 12th annual ieeeacm international symposium on code generation and optimization cgo, 2014.
On the gpu, main memory is accessed via a cache hierarchy where, in most cases, the l1 data cache is not coherent. In addition, it ensures forward progress through an automatic serialization mechanism. This dissertation aims to reduce the burden on gpu software developers with two major enhancements to gpu architectures. Transactional memory tm is an optimistic approach to achieve this goal. Hardware transactional memory for gpu architectures wilson w. To evaluate tlll, we use it to implement six widely used programs, and compare it with the stateoftheart adhoc gpu synchronization, gpu software transactional memory stm, and cpu hardware. Towards a software transactional memory for heterogeneous. Advanced computer architecture and systems detailed. Exploration of lockbased software transactional memory justin gottschlich. The major challenges include ensuring good scalability with respect to the massively multithreading of gpus, and.
To make applications with dynamic data sharing benefit from gpu acceleration, we propose a novel software transactional memory system for gpu architectures gpustm. To make applications with dynamic data sharing among threads benefit from gpu acceleration, we propose a novel software transactional. Towards a software transactional memory for heterogeneous cpu. The major challenges include ensuring good scalability with respect to the massively multithreading of gpus, and preventing livelocks caused by the simt execution paradigm of gpus. Nov 11, 20 compiler, architecture and tools conference program abstracts. Matt software transactional memory, herlihys hardware accelerator concept.
Towards a software transactional memory for graphics processors. Data layout transformation for enhancing locality on nuca chip multiprocessors. An efficient software transactional memory using committime invalidation. To make applications with dynamic data sharing among threads benefit from gpu acceleration, we propose a novel software transactional memory system for gpu architectures gpu stm. Hardware transactional memory for gpu architectures.
Secondly, the con ict detection mechanism is based on uni ed readwrite signatures i. However, performance and energy overhead of kilo tm may deter gpu vendors from incorporating it into future designs. Were upgrading the acm dl, and would like your input. Sadayappan, yongjian chen, haibo lin and tinfook ngai. The major challenges include ensuring good scalability with respect to the massively multithreading of gpus, and preventing livelocks. Hardware transactional memory for gpu architectures ubc ece. Next generation cuda architecture, code named fermi. It is only accessible by the gpu and not accessible via the cpu. Transactional synchronization extensions wikipedia.
Accelerating gpu hardware transactional memory with snapshot. Efficient transactionalmemorybased implementation of morph. Qingda lu, christophe alias, uday bondhugula, sriram krishnamoorthy, j. Today most people who make effective use of gpus undergo a steep learning curve and are forced to program close to the machine using special gpu programming languages. Pdf hardware transactional memory for gpu architectures. Toward a software transactional memory for heterogeneous cpu. However, ensuring atomicity for complex data types is a task delegated to programmers. Many tm systems have been proposed in the last two decades for multicore architectures 7, implemented either in hardware or software or a combination. Both hardware and software transactional memories have been proposed for the gpu architectures. Cpu and gpu architectures, memory subsystem design, hardwaresoftware codesign.
Sep 15, 2008 3 the graphics memory is the gpu s version of host memory. Aamodt university of british columbia, canada motivation. Gpu localtm allocates transactional metadata in the existing memory resources, minimizing the storage requirements for tm support. Improvements in hardware transactional memory for gpu architectures 3 proposed. Software transactional memory for gpu architectures nilanjan. Toward a software transactional memory for heterogeneous. First, thread block compaction tbc is a microarchitecture innovation that reduces the performance penalty caused by branch divergence in gpu applications. Tm simplifies software development for parallel architectures by providing the programmer with the illusion that code blocks, called transactions, execute. Thesis, department of electrical and computer engineering, university of colorado. Tm transactional memory stm software transactional memory htm hardware transactional memory hytm hybrid transactional memory tsx intels transactional synchronization extensions hle hardware lock elision rtm restricted transactional memory gpu graphics processing unit gpgpu general purpose computation on graphics processing units cpu central. Acle version acle q3 2019 acle acle q3 2019 documentation. Each kernel launch dispatches a hierarchy of threads a grid of blocks. Gpu computing architecture for irregular parallelism ubc.
As the downside, software implementations usually come with a performance penalty, when compared to hardware. Hardware support for local memory transactions on gpu architectures alejandro villegas angeles navarro. One hardware proposal, kilo tm, can scale to s of concurrent transaction. Software transactional memory for gpu architectures proceedings. Software transactional memory for gpu architectures ieee xplore. To make applications with dynamic data sharing among threads benefit from gpu acceleration, we propose a novel software transactional memory system for gpu architectures gpustm. Modern gpu architectures have a memory hierarchy that needs to be explicitly programmed to obtain good performance. Modern apus implement cpugpu platform atomics for simple data types. To improve gpus programmability and thus extend their usage to a wider range of applications, the authors propose to enable transactional memory tm on gpus via kilo tm, a novel hardware tm system that scales to thousands of concurrent transactions. Software transactional memory for gpu architectures ieee. Energy e ciency of software transactional memory in a. View anup holeys profile on linkedin, the worlds largest professional community. Transactional synchronization extensions tsx, also called transactional synchronization extensions new instructions tsxni, is an extension to the x86 instruction set architecture isa that adds hardware transactional memory support, speeding up execution of multithreaded software through lock elision. Scheduling techniques for gpu architectures with processinginmemory capabilities ashutosh pattnaik1 xulong tang1 adwait jog2 onur kay.
Computing without processors august 2011 communications. And now having read about intels hw tm i have many curious questions. Compiler, architecture and tools conference program abstracts. Transactional memory for heterogeneous systems arxiv. Programming gpus is challenging for applications with irregular finegrained communication between threads.
Or would these kinds of building blocks be just what we want. With tm, the programmer does not need to write code with locks to ensure mutual exclusion. Pdf software transactional memory for gpu architectures. Transactional memory for heterogeneous cpugpu systems. Software transactional memory for gpu architectures.