Software transactional memory for gpu architectures

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 graphics processors. An efficient software transactional memory using committime invalidation. It is only accessible by the gpu and not accessible via the cpu. Hardware support for local memory transactions on gpu. To make applications with dynamic data sharing benefit from gpu acceleration, we propose a novel software transactional memory system for gpu architectures gpustm. Efficient transactionalmemorybased implementation of morph. Transactional memory for heterogeneous systems arxiv. If this mechanism is required very often it may harm performance. Modern apus implement cpugpu platform atomics for simple data types.

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. Accelerating gpu hardware transactional memory with snapshot. This dissertation aims to reduce the burden on gpu software developers with two major enhancements to gpu architectures. Many tm systems have been proposed in the last two decades for multicore architectures 7, implemented either in hardware or software or a combination. Hardware transactional memory for gpu architectures. On the gpu, main memory is accessed via a cache hierarchy where, in most cases, the l1 data cache is not coherent. Aamodt university of british columbia, canada motivation. Nilanjan goswami gpu architect advanced computing lab. Pdf modern gpus have shown promising results in accelerating computation intensive and numerical workloads with limited dynamic data sharing.

Hardware transactional memory for gpu architectures ubc ece. As the downside, software implementations usually come with a performance penalty, when compared to hardware. Systemwide data consistency issues can be handled by a gpu friendly design of software transactional memory. Yunlong xu, rui wang, nilanjan goswami, tao li and depei qian. The major challenges include ensuring good scalability with respect to the massively multithreading of gpus, and preventing livelocks. Secondly, the con ict detection mechanism is based on uni ed readwrite signatures i. Hardware support for local memory transactions on gpu architectures alejandro villegas angeles navarro.

Toward a software transactional memory for heterogeneous cpu. For a set of tmenhanced gpu applications, kilo tm captures 59% of the performance of finegrained locking, and is on average 128x faster than executing all transactions serially, for an estimated hardware area overhead of 0. Qingda lu, christophe alias, uday bondhugula, sriram krishnamoorthy, j. 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. Ennals, efficient software transactional memory, technical report, intel research cambridge, uk, 2005. Sep 15, 2008 3 the graphics memory is the gpu s version of host memory. Software transactional memory for gpu architectures ieee. His research interests include parallel programming, software transactional memory, and distributed architectures. The major challenges include ensuring good scalability with respect to the massively multithreading of gpus, and. Each kernel launch dispatches a hierarchy of threads a grid of blocks. To reduce this effort, prior work has proposed supporting transactional memory on gpu architectures.

Toward a software transactional memory for heterogeneous. 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. A question that arises in our smart highways use case is this. View anup holeys profile on linkedin, the worlds largest professional community. Towards a software transactional memory for heterogeneous. Computing without processors august 2011 communications. With tm, the programmer does not need to write code with locks to ensure mutual exclusion. Transactional memory tm is an optimistic approach to achieve this goal. Cpu and gpu architectures, memory subsystem design, hardwaresoftware codesign. A cuda program starts on a cpu and then launches parallel compute kernels onto a gpu. And now having read about intels hw tm i have many curious questions. 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 support for scratchpad memory transactions on gpu. Pdf hardware transactional memory for gpu architectures.

Acle version acle q3 2019 acle acle q3 2019 documentation. Or would these kinds of building blocks be just what we want. Towards a software transactional memory for heterogeneous cpu. Advanced computer architecture and systems detailed. Software transactional memory for gpu architectures ieee xplore. Nov 11, 20 compiler, architecture and tools conference program abstracts. I have been working on software transactional memory for in memory database. 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. Rafael ubal david kaeli department of electrical and computer engineering. We propose gpu localtm, a hardware transactional memory tm, as an alternative to data locking mechanisms in local memory. On the hardware side, kilo tm was proposed in 2011.

Energy e ciency of software transactional memory in a. Software transactional memory for gpu architectures yunlong xu. Were upgrading the acm dl, and would like your input. Improvements in hardware transactional memory for gpu. However, ensuring atomicity for complex data types is a task delegated to programmers. 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. 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. 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. In addition, it ensures forward progress through an automatic serialization mechanism. A stm system that supports perthread transactions faces new challenges.

The heterogeneous accelerated processing units apus integrate a multicore cpu and a gpu within the same chip. Next generation cuda architecture, code named fermi. Gpu localtm allocates transactional metadata in the existing memory resources, minimizing the storage requirements for tm support. Tm simplifies software development for parallel architectures by providing the programmer with the illusion that code blocks, called transactions, execute. The unconverted parts of the java program could use up the cpu multicore resources with its multithreaded workload. Software transactional memory for gpu architectures nilanjan.

Software transactional memory for gpu architectures. Programming gpus is challenging for applications with irregular finegrained communication between threads. Pdf software transactional memory for gpu architectures. Sadayappan, yongjian chen, haibo lin and tinfook ngai. Gpu computing architecture for irregular parallelism ubc. First, thread block compaction tbc is a microarchitecture innovation that reduces the performance penalty caused by branch divergence in gpu applications. Both hardware and software transactional memories have been proposed for the gpu architectures. Software transactional memory for gpu architectures proceedings. Data layout transformation for enhancing locality on nuca chip multiprocessors. Hardware transactional memory for gpu architectures wilson w. Transactional synchronization extensions wikipedia. Scheduling techniques for gpu architectures with processinginmemory capabilities ashutosh pattnaik1 xulong tang1 adwait jog2 onur kay. However, performance and energy overhead of kilo tm may deter gpu vendors from incorporating it into future designs. Scheduling techniques for gpu architectures with processing.

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. 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. One hardware proposal, kilo tm, can scale to s of concurrent transaction. To appear in the 12th annual ieeeacm international symposium on code generation and optimization cgo, 2014.

To make applications with dynamic data sharing among threads benefit from gpu acceleration, we propose a novel software transactional. Modern gpu architectures have a memory hierarchy that needs to be explicitly programmed to obtain good performance. Compiler, architecture and tools conference program abstracts. Improvements in hardware transactional memory for gpu architectures 3 proposed. Matt software transactional memory, herlihys hardware accelerator concept. 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. In this paper, we analyze the performance and energy ef. Transactional memory for heterogeneous cpugpu systems. Exploration of lockbased software transactional memory justin gottschlich.