setting processor affinity with C++ that will run

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Closed 8 years ago.

Possible Duplicate:
CPU Affinity

I'm running on Linux and I want to write a C++ program that will set 2 specific processors that my 2 applications that will run in parallel (i.e. setting each process to run on a different core/CPU). I want to use processor affinity tool with C++. Please can anyone help with C++ code.

Answer 1

From the command line you can use taskset(1), or from within your code you can use sched_setaffinity(2).

E.g.

#ifdef __linux__    // Linux only
#include <sched.h>  // sched_setaffinity
#endif

int main(int argc, char *argv[])
{
#ifdef __linux__
    int cpuAffinity = argc > 1 ? atoi(argv[1]) : -1;

    if (cpuAffinity > -1)
    {
        cpu_set_t mask;
        int status;

        CPU_ZERO(&mask);
        CPU_SET(cpuAffinity, &mask);
        status = sched_setaffinity(0, sizeof(mask), &mask);
        if (status != 0)
        {
            perror("sched_setaffinity");
        }
    }
#endif

    // ... your program ...
}

Answer 2

You need to call sched_setaffinity or pthread_setaffinity_np

See also this question