1
голосов
3ответов
208 просмотров

What am I doing wrong in this F# code?

let parallelTest n = Color(Color.DeepPink, Triangles(sphere n));; Parallel.For(0,10,new Action(parallelTest));; Error message : error FS0001: Type mismatch. Expecting a int -> unit but given a int -> scene. The type 'unit' does not match the type 'scene' I'll glad if some body ...

30
голосов
5ответов
11468 просмотров

What are some scenarios for which MPI is a better fit than MapReduce?

As far as I understand, MPI gives me much more control over how exactly different nodes in the cluster will communicate. In MapReduce/Hadoop, each node does some computation, exchanges data with other nodes, and then collates its partition of results. Seems simple, but since you can iterate the ...

12
голосов
7ответов
3155 просмотров

Getting starting with Parallel programming

So it looks like multicore and all its associated complications are here to stay. I am planning a software project that will definitely benefit from parallelism. The problem is that I have very little experience writing concurrent software. I studied it at University and understand the concepts a...

1
голосов
2ответов
2379 просмотров

Intel Fortran Compiler "-parallel" Not Working

I have a serial Fortran code that works fine. Once I compile the same code using ifort -parallel and run it, it gives wrong results and overflow. I would expect that with "-parallel" flag, the Intel compiler is capable of selecting the loops that are safe to parallelize and I should get the exact...

4
голосов
4ответов
3368 просмотров

C# Events: How to process event in a parallel manner

I have an event which I would like to have processed in a parallel manner. My idea is to make each callback be added to the ThreadPool, effectivley having each method that registered the event handled by the ThreadPool. My try-out code looks something like the following: Delegate[] delegates = ...

1
голосов
3ответов
1492 просмотров

Parallelizing nested loops with dependencies

My question is about how best to structure my (C++) code to support parallelizing a time consuming computation. The pseudocode in question has the following structure: for a_1(y_1) in A_1 for a_2(y_2) in A_2(a_1) ... for a_n(y_n) in A_n(a_1, ..., a_{n-1}) ...

9
голосов
4ответов
2035 просмотров

Is there any Non-blocking IO open source implementation for Scala's actors?

I have quite large files that I need to deal with (500Meg+ zip files). Are there any non-blocking IO open source implementations for Scala's actors?

8
голосов
1ответов
854 просмотров

Parallel pipelining

(fileNameToCharStream "bigfile" |>> fuse [length; splitBy (fun x -> x = ' ' || x = '\n') removeEmpty |>> length; splitBy (fun x -> x = '\n') keepEmpty |>> length; ]) (*fuse "fuses" the three functions to run concurrently*) |> run 2 ...

1
голосов
1ответов
492 просмотров

Non-trivial private data in Fortran90 OpenMP

I have a section of a Fortran90 program that should be parallelized with OpenMP. !$omp parallel num_threads(8) & !$omp private(j, s, prop_states) & !$omp firstprivate(targets, pulses) ! ... modify something in pulses. targets(s)%ham contains pointers to ! elements of pulses ... do...

0
голосов
1ответов
85 просмотров

A question about parallelizing a task

I have a question about parallelization: I have two datasets. Dataset1 has m rows and k columns, Dataset2 has n rows and k columns.(m> n) My program reads those datasets from files and store them in the memory. The task is to take each instance of Dataset1(let's call this query instance) and ...

4
голосов
4ответов
1280 просмотров

MATLAB: function makes 4 recursive calls. I have a 4-core processor. Can I parallelize?

I have a 4-core processor and have a recursive Matlab function which makes four recursive calls: function J = do_stuff(I) if some_condition(I) J = blah_blah(I); else [I1,I2,I3,I4] = split4(I); J1 = do_stuff(I1); J2 = do_stuff(I2); J3 = do_stuff(I3); J4 = do_stuff(I4); ...

17
голосов
6ответов
4204 просмотров

How to create Chrome like application in Delphi which runs multiple processes inside one Window?

Is it possible to create an "application group" which would run under one window, but in separate processes, like in Chrome browser? I'd like to divide one application into multiple parts, so that one crashing or jamming process cannot take down others, but still keep the look and feel as close t...

3
голосов
1ответов
1013 просмотров

Generate vector code from Haskell?

Is it possible to get GHC to produce SIMD code for the various SSE generations? Eg. got a program like this import Data.Array.Vector main = print . sumU $ (enumFromToFracU 1 10000000 :: UArr Double) I can see the generated code (compiled for 64 bit x86) use SSE instructions in scalar mode (bo...

0
голосов
4ответов
268 просмотров

How to predict the behavior of a system based on previous behavior

I am looking for an algorithm that, based on the previous behavior of a system, predicts the future behavior. I'm building a parallel memory allocator that has a public list of empty blocks. Each thread, when it needs, can take blocks from this list and allocate from them. The blocks are group...

8
голосов
4ответов
941 просмотров

Non-linear scaling of .NET operations on multi-core machine

I've encountered a strange behavior in a .NET application that performs some highly parallel processing on a set of in-memory data. When run on a multi-core processor (IntelCore2 Quad Q6600 2.4GHz) it exhibits non-linear scaling as multiple threads are kicked off to process the data. When run a...

1
голосов
2ответов
5196 просмотров

How to determine the optimum number of worker threads

I wrote a C program which reads a dataset from a file and then applies a data mining algorithm to find the clusters and classes in the data. At the moment I am trying to rewrite this sequential program multithreaded with PThreads and I am newbie to a parallel programming and I have a question ab...

2
голосов
2ответов
1456 просмотров

Multi threaded FFTW 3.1.2 on a shared memory computer

I use FFTW 3.1.2 with Fortran to perform real to complex and complex to real FFTs. It works perfectly on one thread. Unfortunately I have some problems when I use the multi-threaded FFTW on a 32 CPU shared memory computer. I have two plans, one for 9 real to complex FFT and one for 9 complex to ...

23
голосов
4ответов
5992 просмотров

Just how good is VTK?

I have heard some good reviews of the Visualization ToolKit (VTK) from developers. But exactly how powerful is it? For example, can it handle visualization of an entire oil reservoir (in a simulator) with billions of grids points? Most industrial reservoir simulators run on parallel processors. I...

0
голосов
1ответов
830 просмотров

How to use foreach with snow for multicore in Windows XP?

Could you please give an example on how that might be done using the doSNOW ? (I asked the same question here, but only got a partial reply) Tal

1
голосов
1ответов
1493 просмотров

Parallel server-side processing of Sharepoint Web Parts

Here's the scenario. I have a number of Sharepoint Web Parts which display data to the user in a grid format. They all connect to a navigation web part which the user can use to select parameters for each of the data grids. On the back end, the grid web part calls a DI container to get an "IDataP...

6
голосов
1ответов
18644 просмотров

Oracle parallel query - How to find out actual number of spawned processes?

I am using Oracle parallel query feature on a 10G 3-node RAC where each node is a 16-CPU machine. The question is, how can I see the actual number of Oracle processes spawned to execute the query on all 3 nodes?

2
голосов
2ответов
586 просмотров

Grand Central Dispatch versus Cilk++

Anybody have any thoughts on Grand Central Dispatch (which has now been open-sourced by Apple) and Cilk++? Comparisons/contrasts? Is Cilk more Windows-only?

10
голосов
1ответов
3143 просмотров

How can you profile a parallelized Python script?

Suppose I have a python script called my_parallel_script.py that involves using multiprocessing to parallelize several things and I run it with the following command: python -m cProfile my_parallel_script.py This generates profiling output for the parent process only. Calls made in child proce...

4
голосов
1ответов
1459 просмотров

.NET MPI implementation?

What is the most mature .NET MPI implementation? A quick google search turned up the two below, but I'm not familiar with either of them. I believe the first item (mpi.net) is based on Microsoft MPI. Any thoughts? http://www.osl.iu.edu/research/mpi.net/ http://www.purempi.net/

1
голосов
2ответов
984 просмотров

ATI Stream SDK on ubuntu 9.04

I have used ATI Stream SDK on windows XP SP3 and implemented one algorithm on GPU. But Now I am interested in scaling this algorithm on multiple GPUs on mutiple machines I switched to UBUNTU to use MPI ( To send messages ). I googled this but I got references for installation on SLES and RHEL bu...

2
голосов
3ответов
596 просмотров

How to scale cholesky factorization on multiple GPUs

I have implemented Cholesky Factorization for solving large linear equation on GPU using ATI Stream SDK. Now I want to exploit computation power of more and more GPUs and I want to run this code on multiple GPUs. Currently I have One Machine and One GPU installed on it and cholesky factorization...

30
голосов
7ответов
46137 просмотров

How to make R use all processors?

I have a quad-core laptop running Windows XP, but looking at Task Manager R only ever seems to use one processor at a time. How can I make R use all four processors and speed up my R programs?

5
голосов
3ответов
1404 просмотров

How can I identify the Selenium Grid host running my test from within the test?

I am using Selenium Grid with TestNG to run my tests in parallel. I have certain tests that require a user to be logged in, so I have a user account configured for testing. I have been careful to ensure that any tests involving logging in as my test user are run on separate virtual machines so t...

3
голосов
10ответов
2037 просмотров

Best way to decouple (for parallel processing) a web application's non-immediate processes?

I'm looking for a good strategy to truly decouple, for parallel processing, my web application's (ASP.NET MVC/C#) non-immediate processes. I define non-immediate as everything that doesn't require to be done right away to render a page or update information. Those processes include sending emai...

3
голосов
7ответов
2586 просмотров

Is there a parallel processing implementation of HashMap available to Java? Is it even possible?

Searching for the magic ParallelHashMap class More succinctly, can you use multiple threads to speed up HashMap lookups? Are there any implementations out there that do this already? In my project, we need to maintain a large map of objects in memory. We never modify the map after it is created...