( nThreads ); std::cout << std::endl; std::cout << "With no chunksize passed:" << std::endl; // Parallelise the for loop using the dynamic schedule #pragma omp parallel for schedule(dynamic) for ( int i = 0; i < 10; ++ i ) { std::cout << "Thread " << omp_get_...
在上面的示例中,我们使用了#pragma omp parallel for指令来并行化循环,并使用reduction(+:sum)来确保对sum变量的并行更新是安全的。 动态调度:在处理不均匀工作负载的情况下,可以使用OMP的动态调度机制来平衡工作负载。例如,在下面的示例中,我们使用#pragma omp parallel for schedule(dynamic)指令来实现动态调度: #...
试想一下,如果我们将chunk等于5的话,那么openMP会为for工作共享构造分配3个线程,线程0、线程1会得到5的迭代量,线程2只能分配chunk=2的迭代量。因为12/5的余数为2。 schedule dynamic 子句 #pragma omp parallel for schedule(dynamic [,chunk]): 为多个并行的线程动态分配迭代量,这个迭代量保证并低于chunk指定的...
b[N],c[N];for(i=0;i<N;i++){a[i]=i;b[i]=i;}# num_threads的数量可以写在#pragma里面也可以放在外面,# 先指定线程数,再设定#pragmaomp parallel num_threads(2) shared(a,b) private(i){#pragmaomp for schedule(dynamic,100) nowaitfor(i=0;i<N;i++){c[i]=a[i]+b[i];}...
OMP_SCHEDULE=“guided, 4” Valid options for schedule type are: auto dynamic[,n] guided[,n] static[,n] If specifying a chunk size withn, the value ofnmust be a positive integer. The default schedule type isauto. Parent topic:Environment variables for OpenMP ...
ordered指令用于控制一段代码在for循环中的执行顺序,它保证这段代码一定是按照for中的顺序依次执行的。 #pragma omp parallel for ordered schedule(dynamic)for (int i = 0; i < 10; ++i){ Data data = ReadFile(files[i]);#pragma omp ordered PutDataToDataset(data);}123456 ...
OMP_SCHEDULE applies only to for and parallel for directives that have the schedule type runtime. The schedule type and chunk size for all such loops can be set at run time by setting this environment variable to any of the recognized schedule types and to an optional chunk_size.For...
You can use omp_sched_guided for a similar functionality. modifier Default integer. For the schedule type dynamic, guided, or static, modifier is the chunk size that is set. For the schedule type auto, modifier has no meaning. Result Type and Attributes None. Result Value None....
OMP_SCHEDULE:用于for循环并行化后的调度,它的值就是循环调度的类型; ** OMP_NUM_THREADS**:用于设置并行域中的线程数; ** OMP_DYNAMIC**:通过设定变量值,来确定是否允许动态设定并行域内的线程数; ** OMP_NESTED**:指出是否可以并行嵌套。 6. 简单的语句——开始并行!
Is loop i an iterative loop for making test runs or a distribution (slicing) loop?If used to increase test runs then the do j loop would be the one you parallize.!$OMP parallel default(shared) private(i)!$omp do schedule(dynamic)iloop:do i=1,N!$OMP CRITICALwrite(*,*) i, omp_ge...