OpenMP Based Fast Data Searching with Multithreading

OpenMP Based Fast Data Searching with Multithreading V.Karthikeyan, Dr. S.Ravi  and S.Flora Magdalene Abstract The multiprocessor cores with multithreaded capability are continuing to gain a significant share and offer high performance. The use of OpenMP applications on two parallel architectures can identify architectural bottlenecks and introduces high level of resource sharing in multithreading performance complications. An adaptive run-time mechanism provides additional but limited performance improvements on multithreading and is maximized the efficiency of OpenMP multithreading as required by the runtime environment and the programming interface. This paper handles the task of data searching efficiently and a comparative analysis of performance with and without OpenMP is made. Experimental result shows accelerated performance over the existing methods in terms of various performance criteria. Keywords: OpenMP (Open Multi Processing), Multithreading, Fast Data Searching, Multicore Introduction OpenMP is an adopted shared memory parallel programming interface providing high level programming constructs that enable the user to easily expose an application task and loop level parallelism. The range of OpenMP applicability is significantly extended by the addition of explicit tasking features.OpenMP is used for enhanced portability computation, where a dynamic workload distribution method is employed for good load balancing. However, the search network involved in the Viterbi beam search is reported by [5] statically partitioned into independent subtrees to reduce memory synchronization overhead. It improves the performance of a workload predictive thread assignment strategy and a false cache line sharing prevention method is required. OpenMP is a collection of compiler directives and library functions that are used to create parallel programs for shared-memory computers. It combines with C, C++ or Fortranto create a multithreaded program where the threads share the address sp ace and make easier for programmers to convert single-threaded code to multithreaded. It has two key concepts namely; Sequential equivalence: Executes using one thread or many threads. Incremental parallelism: A programming that evolves incrementally from a sequential program to a parallel program. OpenMP has an advantage in synchronization over hand-threading where it uses more expensive system calls than present in OpenMP or the code efficient versions of synchronization primitives. As a shared-memory programming paradigm, OpenMP is suitable for parallelizing applications on simultaneous multithreaded and multicore processors as reported in [11]. It is an API (application program interface) used for explicitly direct multi-threaded, shared memory parallelism to standardize programming extensions for shared memory machines is shown in Figure 1. Figure1:Model for OpenMP Program using threading At high-end, the microprocessors encompass aggressive multithreading and multicore technologies to form powerful computational building blocks for the super computers. The evaluation uses detailed performance measurements and information from hardware performance counters to architectural bottlenecks of multithreading and multicore processors that hinder the scalability of OpenMPin which OpenMP implementations can be improved to better support execution on multithreading processors. The thread scheduling based model with kernel and user space is shown in Figure 2.OpenMP applications can efficiently exploit the execution contexts of multithreading processors. The multi-threading models are; Master-Slave model, Worker-Crew model and Pipeline model Figure 2:Multithreading processors using Kernel and User space OpenMP Issues with Multithreading Approach OpenMP specification includes critical, atomic, flush and barrier directives for synchronization purposes as shown in Table 1. Table 1:OpenMP synchronization specification Effects of OpenMP for Multithreading Process The effects of OpenMP for multithreading process arelisted in Table 2. Table 2:Effects of OpenMP The multithreading is required a solution which is scalable in a number of dimensions and achieve speedups. An efficient parallel program usually limits the number of threads to the number of physical cores that create a large number of concurrent threads. It describes the low-level Linux kernel interface for threads and the programs are invoked by a fork system call which creates a process and followed by an exec system call and loads a program to starts execution. Threads typically end by executing an exit system call, which can kill one or all threads. Related Works Daniel, et al., [2010] presented the compilation of synchronous programs to multi-threaded OpenMP-based C programs and guarded actions which are a comfortable intermediate language for synchronous languages. J. Brandt and K. Schneider [2009] presented separate compilation of synchronous programs. The target deterministic single-threaded code directly executes synchronous programs on simple micro-controllers. K. Schneider [2009] proposed the problem to generate multi-threaded C-code from synchronous guarded actions, which is a comfortable intermediate format for the compilation of synchronous programs. PranavandSumit [2014] proposed the performances (speedup) of parallel algorithms on multi-core system using OpenMP. C.D. Antonopoulos, et al., [2005] proposed multigrain parallel delaunay mesh generation and opportunities for multithreaded architectures. H. Jin, et al., [1999] proposed the OpenMP implementation of NAS parallel benchmarks and its performance. M. Lee, et al., [2004] presented peak performance of SPEC OMPL benchmarks using maximum threads demonstration and compared with a traditional SMP. Zaid, et al., [2014] presented to implemented the bubble sort algorithm using multithreading (OpenMP) and tested on two standard data sets (text file) with different sizeF. Liu and V. Chaudhary [2003] presented a system-on-chip (SOC) design integrates processors into one chip and OpenMP is selected to deal with the heterogeneity of CMP.M. Sato, et al., [1999] proposed the compiler is installed to support OpenMP applications and GCC acts as a backend compiler.T. Wang, et al., [2004] presented the current flat view of OpenMP threads is not able to reflect the new features and need to be revisited to ensure continuing applicability.Cristiano et al., [2008] proposed reproducible simulation of multi-threaded workloads for architecture design exploration.Vijay Sundaresan, et al., [2006] proposed experiences with multi-threading and dynamic class loading in a java just-in-time compiler. Priya, et al., [2014] proposed to compare and analyze the parallel computing ability offered by OpenMP for Intel Cilk Plus and MPI(Message passing Interface). Sanjay and Kusum [2012] presented to analyze the parallel algorithms for computing the solution of dense system of linear equations and to approximately compute the value of OpenMP interface. S.N. TirumalaRao [2010] focuses on performance of memory mapped files on Multi-Core processors and explored the potential of Multi-Core hardware under OpenMP API and POSIX threads. Explicit Multithreading Using Multithreads The Explicit multithreading is more complex compared to OpenMP and dynamic applications need to be implemented effectively so as to allow user control on performance. The explicit multithreading based multithreads with C coding are shown in Figure 3. Figure3: Explicit multithreading based coding in C Scheduling for OpenMP OpenMP supports loop level scheduling that defines how loop iterations are assigned to each participating thread. The scheduling types are listed in Table 3. Table 3:  Scheduling Types Pseudo code: #pragma omp parallel sections { #pragma omp section do_clustering(0); #pragma omp section do_clustering(1); #pragma omp section do_clustering(2); #pragma omp section do_clustering(3); #pragma omp section do_clustering(4); } Optimizing Execution Contexts on Multithreading Process The selection of the optimal number of execution contexts for the execution of each OpenMP application is not trivial on multithread based multiprocessors. Thus, a performance-driven, adaptive mechanism which dynamically activates and deactivates the additional execution contexts on multithreading processors to automatically approximate the execution time of the best static selection of execution contexts per processor. It used a mechanism than the exhaustive search, which avoids modifications to the OpenMP compiler and runtime and identifies whether the use of the second execution context of each processor is beneficial for performance and adapts the number of threads used for the execution of each parallel region. The algorithm targets identification of the best loop scheduling policy which is based on the annotation of the beginning and end of parallel regions with calls to runtime. The calls can be inserted automatically, by a simple preprocessor. The run-time linking techniques such as dynamic interposition can be used to intercept the calls issued to the native OpenMP runtime at the boundaries of parallel regions and apply dynamic adaptation even to un modified application binaries. It modifies the semantics of the OpenMP threads environment variable,using it as a suggestion for the number of processors to be used instead of the number of threads. Results and Discussion The experimental results of data searching with OpenMP tools (multithreading) and without OpenMP (no multithreading) tools are shown in Figure 4and Figure 5 respectively. In both the cases search time for data is evaluated and established OpenMP based implementation which is fast compared to data searching done without OpenMP tools. Figure 4:Search time with OpenMP (Multithreading) Figure5:Search time without OpenMP (No Multithreading) The percentage of improvement in data searching with OpenMP (multithreading) tools is given in Table 4 and its graphical representation shown in Figure 6. Table 4:Improvement with Multithreading Figure6:Improvement in data Searching with OpenMP (in %) The time elapsed to write data in file which is experimented with OpenMP and without OpenMP (search data) shown in Figure 7 and Figure 8 respectively. Figure 7:Search datawith OpenMP Figure 8:Search datawithout OpenMP Conclusion Searching a data in large data base has been a profound area for researchers. In this research work OpenMP Tools is used to perform multithreading based search. The motive to use OpenMP is that the user can specify a paralliazation strategy for a program. Here an experiment of data searching using multithreading is conducted for a data base. The experiments are conducted with and without OpenMP and their performance is presented. The results obtained shows that the time required for searching a data using OpenMP is less compared to data searching without OpenMP. The method presented shows improved performance over existing methods in terms of performance and parallaziation can be done in future. The main limitation of the research work is that its practical implementation requires same number of multicore units as that of the number of threads. Future research shall focus on use of parallel threads for high performance systems. References Daniel Baudisch, Jens Brandt and Klaus Schneider, 2010, â€Å"Multithreaded Code from Synchronous Programs: Extracting Independent Threads for OpenMP†, EDAA. J. Brandt and K. Schneider, 2009, â€Å"Separate compilation of synchronous programs†, in Software and Compilers for Embedded Systems (SCOPES), ACM International Conference Proceeding Series, Vol. 320, pp. 1–10, Nice, France. K. Schneider, 2009, â€Å"The synchronous programming language Quartz†, Internal Report 375, Department of Computer Science, University of Kaiserslautern, Kaiserslautern, Germany. PranavKulkarni, SumitPathare, 2014, â€Å"Performance Analysis of Parallel Algorithm over Sequential using OpenMP†, IOSR Journal of Computer Engineering, Vol. 16, No. 2, pp. 58-62. C. D. Antonopoulos, X. Ding, A. Chernikov, F. Blagojevic, D. S. Nikolopoulos and N. Chrisochoides, 2005, â€Å"Multigrain Parallel Delaunay Mesh Generation: Challenges and Opportunities for Multithreaded Architectures†, in Proceeding of the 19thACM International Conference on Supercomputing (ICS’2005), Cambridge, USA. H. Jin, M. Frumkin and J. Yan, 1999, â€Å"The OpenMP Implementation of NAS Parallel Benchmarks and its Performance†, Technical Report NAS-99-011, NASA Ames Research Center. M. Lee, B. Whitney and N. Copty, 2004, â€Å"Performance and Scalability of OpenMP Programs on the Sun FireTM E25K Throughput Computing Server†, WOMPAT 2004, pp. 19-28. ZaidAbdiAlkareemAlyasseri, Kadhim Al-Attar and Mazin Nasser, 2014, â€Å"Parallelize Bubble Sort Algorithm Using OpenMP†, International Journal of Advanced Research in Computer Science and Software Engineering, Vol. 4, No. 1, pp. 103-110. F. Liu and V. Chaudhary, 2003, â€Å"Extending OpenMP for heterogeneous chip multiprocessors Parallel Processing†, Proceedings of International Conference on Parallel Processing, pp. 161-168. M. Sato, S. Satoh, K. Kusano and Y. Tanaka, 1999, â€Å"Design of OpenMP compiler for an SMP cluster†, Proc. of the 1st European Workshop on OpenMP, pp.32-39. T. Wang, F. Blagojevic and D. S. Nikolopoulos, 2004, â€Å"Runtime Support for Integrating Pre-computation and Thread-Level Parallelism on Simultaneous Multithreaded Processors†, the Seventh Workshop on Languages, Compilers, and Run-time Support for Scalable Systems, Houston, TX. Cristiano Pereira, Harish Patil and Brad Calder, 2008, â€Å"Reproducible simulation of multi-threaded workloads for architecture design exploration†, in Proceedings of the IEEE International Symposium on Workload Characterization, pp. 173-182. Vijay Sundaresan, Daryl Maier, PramodRamarao and Mark Stoodley, 2006, â€Å"Experiences with multi-threading and dynamic class loading in a java just-in-time compiler†, in International Symposium on Code Generation and Optimization, pp. 87–97, San Francisco, USA. Priya Mehta, Sarvesh Singh, Deepika Roy and M. Manju Sharma, 2014, â€Å"Comparative Study of Multi-Threading Libraries to Fully Utilize Multi Processor/Multi Core Systems†, International Journal of Current Engineering and Technology, Vol. 4, No. 4. Sanjay Kumar Sharma and Kusum Gupta, 2012, â€Å"Performance Analysis of Parallel Algorithms on Multi-core System using OpenMP†, International Journal of Computer Science, Engineering and Information Technology, Vol. 2, No. 5. S.N. TirumalaRao, E.V. Prasad, N.B. Venkateswarlu, 2010, â€Å"A Critical Performance Study of Memory Mapping on Multi-Core Processors: An Experiment with k-means Algorithm with Large Data Mining Data Sets†, International Journal of Computer Applications, Vol. 1, No. 9.

Liminality in Dracula Essay

History has taught us that rebelling against your people or religion almost always results in displeasure, as the members of the community usually frown upon it. Throughout the novel Each Man’s Son by Hugh MacLennan, there are two themes which are linked to this topic of defying your origins, though never plainly affirmed: the Celtic identity and the Puritanical predestination-like values. Not conforming to these ways of life demonstrates two themes at which Archie the fighter and Ainslie the dreamer display: the attempt to foster new values will doom you to failure and resisting your religion will only let you yearn for escape but haunt you forever. This paper, will first analyze the meaning of these two themes; second show that Archie fights against the Celtic identity and that Ainslie tries to escape the Puritanical values. First, it is suitable to grasp onto these concepts with the history from the novel concerning the Celtics and the Puritans since it frames the foundational richness of the story. In Each Man’s Son the symbolic references on the history concerning the Celtic identity is manifested as â€Å"a Homeric people† in ultimate solitude, which proves to be symbolic due to the fact that it ties meaning to the Highland people as a â€Å"desperate and poetic/race of hunters, shepherds and warriors† (MacLennan 1, 2). The novel is full of richness, which provides ironic information about the people: who were found â€Å"older than France† with â€Å"no organization† (MacLennan 25-5). This characteristic given to the men of Cape Breton is highly relevant to the plot as Archie choses to literally fight the regulatory social norms of the Celtic identity when he follows his dreams to become an American boxer. In the novel, the Celtic identity is in direct conflict with Puritan values within certain characters, especially Ainslie. Presbyterians note that they â€Å"live and die under the wrath of an arbitrary God who will forgive only a handful of His elect on the Day of Judgment† (MacLennan 2). The value of the quote symbolizes an underlining view on the Puritan religion as it describes how the Calvinists must live a basic life in order to be resurrected with eternal life. In the Bible, which Puritans follow unfailingly, it is written, â€Å"you must be born from above† meaning that you must have â€Å"been chosen according to the foreknowledge of God the Father† (John 3:7, 1 Peter 1:2 NIV). Furthermore, religion takes a crowning importance in the novel as it acts as the basic yet powerful feature of the story. Numerous characters struggle to adopt their identity, namely Doctor Ainslie for he attempts to darken his religious distinctiveness. The lacing of the Celtic identity and the Puritan religion represents tension, which Archie the fighter and Ainslie the dreamer must overcome. Second, Archie is a clear example of a character who conflicts with the Celtic identity because although he is acclaimed as the â€Å"bravest man in Cape Breton†, â€Å"fierce and unpredictable†, unlike the flock of people, he was a â€Å"hero whom nobody understood and everyone admired†; unfortunately, he is also destined to fail (MacLennan 12-8-6). â€Å"Archie is a hero† with grandiose â€Å"physical strength† who was loved â€Å"because he was giving significance, even a crude beauty, to the clumsy courage they all felt in themselves† (MacLennan 19-9). Generally Celtics feel that destiny works against them; they feel that luck must have been against them. This illustrates that the repercussion of rebelling against the Celtic identity is absolutely forbidden. The Celtic character is normally condemned to a life of simplicity, total depravity and unconditional fellowship of God and as Archie ventures the unknown he distorts the norm. Animalistic Archie emphasizes that some men will â€Å"live their whole lives like oxes and cows† and that he is â€Å"not one of them† this statement, in other words, means that Archie does not intend on living a reclusive life as he fully intends on going out into the world, in spite of the consequences, to create a new life for himself and his family. He had â€Å"left his home to find wider opportunities in the United States† (MacLennan 3). Ironically, as Archie attempts to make money and follow his dream of becoming a boxer he refuses to obey the Celtic norm and is doomed to fail; he is left defeated by his embedded Celtic identity. The final character, which shows prominent struggles, concerning following norms is Ainslie: the dreamer. This is due to the fact that he is resistant to his Puritan religion, which leaves him yearning for an escape from societal pressures. Quite like Archie, Ainslie is also hopeless, yet in different matters: his religion haunts him not only consciously but also unconsciously in dreams as he is disturbed by religious stories. Traditionally, Puritans live a life in profound guilt, constant criticism and austerity because they believe in predestination at which God has chosen the elect to enter heaven. Though he is living in the pressures of this community he continuously denies his belief in God however it is hard to believe that he is a nonbeliever for he continuously shows signs of religious identity. Ainslie craves for a purpose in his life, an attainable goal a dream to escape this community, yet as the novel unfolds he is left haunted forever by his religious mental state. Ironically, because of the fact that he resists his religion and yearns for an escape, he will be left him undeniably haunted forever. In summary, historical details, Archie and Ainslie in Each Man’s Son emphasize conflicts between the Celtic identity and the Puritan religion. Contrasting the two characters, I find it much more rewarding to explore who you are and discover your identity instead of fighting or denying it because then you will not become a failure or be tormented by it. Unlike Archie and Ainslie, I had opportunities to participate in accomplishments that have given me a positive understanding of my identity while I was growing up, which undeniably shaped who I am today. Works Cited MacLennan, Hugh. Each Man’s Son. Toronto: The New Canadian Library, 2003. Print. New International Version Holy Bible. Grand Rapids: Zondervan, 1986. Print.

Descartes Myth-Gilbert Ryle - 1044 Words

Gilbert RyleÂ’s The Concept of Mind Gilbert Ryle (1900-76) was a philosopher who taught at Oxford and who made important contributions to the philosophy of mind and to ordinary language philosophy. His most important writings included Philosophical Arguments (1945), The Concept of Mind (1949), Dilemmas (1954), Plato s Progress (1966), and On Thinking (1979). The Concept of Mind (1949) is a critique of the notion that the mind is distinct from the body, and it is a rejection of the theory that mental states are separable from physical states. According to Ryle, the classical theory of mind, as represented by Cartesian rationalism, asserts that there is a basic distinction between mind and matter. However, the classical theory makes a†¦show more content†¦Thus, the mind consists of various abilities or dispositions that explain such behaviors as learning, remembering, knowing, feeling, or willing. However, personal abilities or dispositions are not the same as mental processes or events. To refer to abilities or dispositions as if they are mental occurrences is to make a basic kind of category-mistake. The nature of a personÂ’s motives may be defined by the actions and reactions of that person in various circumstances or situations. The nature of a person s motives in a particular situation may not necessarily be determined by any hidden mental processes or intellectual acts within that person. Motives may be revealed or explained by a personÂ’s behavior in a situation. Ryle criticizes the theory that the mind is a place where mental images are apprehended, perceived, or remembered. Sensations, thoughts, and feelings do not belong to a mental world distinct from the physical world. Knowledge, memory, imagination, and other abilities or dispositions do not reside within the mind as if the mind were a space in which these dispositions could be situated or located. Furthermore, dispositions are not the same as behavioral actions; actions may, however, be explained by dispositions. Dispositions are neither visible nor hidden, because they are not in the same logical category as behavioral actions. Dispositions are not mental processes or intellectualShow MoreRelatedEssay on Gilbert Ryle’s The Concept of Mind1107 Words   |  5 PagesGilbert Ryle’s The Concept of Mind Gilbert Ryle’s The Concept of Mind (1949) is a critique of the notion that the mind is distinct from the body, and is a rejection of the philosophical theory that mental states are distinct from physical states. Ryle argues that the traditional approach to the relation of mind and body (i.e., the approach which is taken by the philosophy of Descartes) assumes that there is a basic distinction between Mind and Matter. 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How to Use the French Past Subjunctive

The past subjunctive is used for the same reasons as the present subjunctive: to express emotion, doubts, and uncertainty. There is a large variety of situations in which  subjunctive is used, just as there are many different expressions that go along with them. Note that the only difference between the present subjunctive  and the past subjunctive  is tense; usage is the same for both. Construction of the Past Subjunctive The French past subjunctive is a  compound conjugation, which means it has two parts: subjunctive  of the  auxiliary verb  (either  avoir  or  Ãƒ ªtre)past participle  of the main verb Like all French compound conjugations, the past subjunctive may be subject to a grammatical  agreement: When the auxiliary verb is  Ãƒ ªtre, the  past participle  must agree with the subject.When the auxiliary verb is  avoir, the past participle may have to agree with its  direct object. Example 1 Je ne crois pas, quil ait commencà © ce travail. I dont think he started the job yet. Je ne crois pas present tenseil ait subjunctive of  avoircommencà © past participle of commencer Example 2 Il faut que vous soyez partis avant matin. You need to be gone before morning. Il faut que present tensevous soyez subjunctive of  Ãƒ ªtrepartis past participle of partir, in agreement with the subject vous Usage of the Past Subjunctive Le passà © du subjonctif is used to express an uncertain action that supposedly happened before the moment of speaking. We employ it when the verb in the subordinate clause, the verb that follows que, happened before the verb in the main clause. The past subjunctive can be used in a subordinate clause when the main clause is either in the present tense or the past tense. When the Main Clause is in the Present Tense Je suis heureuse que tu sois venu hier. Im happy that you came yesterday.Nous avons peur quil nait  pas mangà ©. Were afraid that he didnt eat. When the Main Clause is in the Past Tense The past subjunctive may be also used in a subordinate clause when the main clause is in the past tense. Note that if the meaning of the main clause did not call for the subjunctive and if the subordinate clause happened before the verb in the main clause, the subordinate clause would have been in plus-que-parfait (the past perfect). (See example below.) For this reason, the subordinate clause should technically be in plus-que-parfait subjonctif (the pluperfect subjunctive), but that is replaced by the past subjunctive in all but the most formal French. An example of main clause—past perfect, subordinate clause—past perfect: Elle savait que je lavais vue. She knew I had seen her. Past subjunctive with main sentence in past tense: Il doutait que vous layez vu. He doubted that you had seen it.Javais peur quils soient tombà ©s.  I was afraid that they had fallen.