parallel-processing

问题 I'm having some problems with C. I am trying to program a parallel port in Windows 7 Professional x64 in VS 2010 Ultimate. Since I do not have a parallel port, I'm using a converter from USB->Parallel and Windows installed the drivers correctly. I've soldered 8 LED-s on the end of the parallel connector and they are all working fine when I connect the USB into the computer. Now, I would like to control the parallel port via my program written in C which is: #include <stdio.h> #include <dos.h>

问题 I'm having some problems with C. I am trying to program a parallel port in Windows 7 Professional x64 in VS 2010 Ultimate. Since I do not have a parallel port, I'm using a converter from USB->Parallel and Windows installed the drivers correctly. I've soldered 8 LED-s on the end of the parallel connector and they are all working fine when I connect the USB into the computer. Now, I would like to control the parallel port via my program written in C which is: #include <stdio.h> #include <dos.h>

问题 GNU Parallel GNU parallel is a shell tool for executing jobs in parallel using one or more computers For example, if I want to write a multicore version of wc I could do: cat XXX | parallel --block 10M --pipe wc -l | awk 'BEGIN{count=0;}{count = count+ $1;} END{print count;}' My question is how to do sorting using parallel? I know what I should do is pipe the result of parallel to a "merge sorted files" command(just like the final merge in merge sort), but I don't know how to do that. 回答1:

问题 I guess the title gives you this thought. Another duplicate question Well, let me explain this in detail. Okay, here we go. I am using gearman to handle stack of tasks. I have a gearman client which send this task to workers. To run these task concurrently, there must be more workers to handle a task at a time. Presently, I create workers as per number of cpus. In my case, its 4 . So, 4 processes . ./worker & ./worker & ./worker & ./worker . I have same file running concurrently. But, I don't

问题 I have a nested loop: (L and A are fully defined inputs) #pragma omp parallel for schedule(guided) shared(L,A) \ reduction(+:dummy) for (i=k+1;i<row;i++){ for (n=0;n<k;n++){ #pragma omp atomic dummy += L[i][n]*L[k][n]; L[i][k] = (A[i][k] - dummy)/L[k][k]; } dummy = 0; } And its sequential version: for (i=k+1;i<row;i++){ for (n=0;n<k;n++){ dummy += L[i][n]*L[k][n]; L[i][k] = (A[i][k] - dummy)/L[k][k]; } dummy = 0; } They both give different results. And parallel version is much slower than the

问题 hi i am converting this c++ ( openmp ) parallel for to c# parallel for but it says : Error 1 Not all code paths return a value in lambda expression of type ' System.Func<int,System.Threading.Tasks.ParallelLoopState,int,int> ' here is my codes : c++ void floyd_warshall(int NumOfThreads) { int i, j, k; omp_set_num_threads(NumOfThreads); for (k = 0; k < n; ++k) #pragma omp parallel for private(i,j) for (i = 0; i < n; ++i) for (j = 0; j < n; ++j) /* If i and j are different nodes and if the paths

问题 I got access to an HPC cluster with a MPI partition. My problem is that -no matter what I try- my code (which works fine on my PC) doesn't run on the HPC cluster. The code looks like this: library(tm) library(qdap) library(snow) library(doSNOW) library(foreach) > cl<- makeCluster(30, type="MPI") > registerDoSNOW(cl) > np<-getDoParWorkers() > np > Base = "./Files1a/" > files = list.files(path=Base,pattern="\\.txt"); > > for(i in 1:length(files)){ ...some definitions and variable generation...

问题 I recently received help with optimizing my code to use generators to save on memory while running code that needs to check many permutations. To put it in perspective, I believe the generator is iterating over a list that has 2! * 2! * 4! * 2! * 2! * 8! * 4! * 10! elements in it. Unfortunately, while I now no longer run out of memory generating the permutations, it is taking >24 hours to run my code. Is it possible to parallelize this through GPU? Generating the iterator with all the above

问题 I recently received help with optimizing my code to use generators to save on memory while running code that needs to check many permutations. To put it in perspective, I believe the generator is iterating over a list that has 2! * 2! * 4! * 2! * 2! * 8! * 4! * 10! elements in it. Unfortunately, while I now no longer run out of memory generating the permutations, it is taking >24 hours to run my code. Is it possible to parallelize this through GPU? Generating the iterator with all the above

问题 We are using 6 iFrames on our page. They fetch data from couple of external web services and an internal WCF service and display the data. There is a separate aspx page built for each of the iFrames. From our perf monitoring we found out that at any point only two threads are executing in parallel. Not all 6 threads get executed. What can probably be cause for this? Is there any restriction that more than 2 threads can't be created in parallel? Is there any configuration where I can change