omp_set_num_threads(NUM_THREADS);#pragmaomp parallel default(none) private(i) shared(nSum, nThreads, nStart, nEnd){#pragmaomp masternThreads = omp_get_num_threads();#pragmaomp forfor(i=nStart; i<=nEnd; ++i) {#pragmaomp atomicnSum += i; } }if(nThreads == NUM_THREADS) { printf...
Kernel Library does not set the default number of OpenMP threads to one, but depends on the OpenMP libraries used with the compiler to set the default number. For the threading layer based on the Intel compiler (libmkl_intel_thread.a), this value is the number of CPUs according to the ...
You can set the number of threads using the environment variableOMP_NUM_THREADS. To change the number of OpenMP threads, use the appropriate command in the command shell in which the program is going to run, for example: For the bash shell, enter: ...
OMP_NUM_THREADS=4 如果不定义OMP_NUM_THREADS,默认会等于CPU数量,在8核心的机器上,会打印出8行"Hello World". omp_set_num_threads(8); 设置了子线程数为8,即是可以有8个子线程并行运行。 #pragma omp parallel private(nthreads,tid) 为编译制导语句,每个线程都自己的nthreads和tid两个私有变量,线程对私有...
Returns the number of threads in the parallel region. C++Copy intomp_get_num_threads( ); Remarks For more information, see3.1.2 omp_get_num_threads function. Example C++Copy // omp_get_num_threads.cpp// compile with: /openmp#include<stdio.h>#include<omp.h>intmain(){ omp_set_num_thr...
report_num_threads(2); #pragma omp parallel num_threads(2) { report_num_threads(3); } } } return(0); } 启用嵌套并行操作时,编译和运行此程序会产生以下(经过排序的)输出: %setenv OMP_NESTED TRUE%a.outLevel 1: number of threads in the team - 2 ...
2. num_threads的设置 3. omp_set_num_threads()库函数的设置 4. OMP_NUM_THREADS环境变量的设置 5. 编译器默认实现(一般而言,默认实现的是总线程数等于处理器的核心数) 2、3、4优先级依次降低的,也就是前面的设置可以覆盖后面的设置,当然也是相对而言,num_threads子句只会影响当前的并行区域,而omp_set_nu...
omp_set_num_threads - 设置并行域中线程格式 omp_get_num_threads - 返回并行域中线程数 omp_get_dynamic - 判断是否支持动态改变线程数目 omp_get_max_threads - 获取并行域中可用的最大的并行线程数目 omp_get_num_procs - 返回系统中处理器的个数 ...
This directive tells the compiler that the structured block of code should be executed in parallel on multiple threads. Each thread will execute the same instruction stream, however not necessarily the same set of instructions. This will depend on control-flow statements s...
As each thread finishes its piece of the iteration space, it dynamically obtains the next set of iterations. When no chunk is specified, it defaults to 1. 1.10.2.3 GUIDED Schedulingschedule(guided[,chunk]) With GUIDED, the chunk size is reduced in an exponentially decreasing manner with ...