pthread round-robin affinity

gistfile1.txt

    static int current_cpu = -1;
    int max_cpus = 8 * sizeof(cpu_set_t);
    cpu_set_t m;
    CPU_ZERO(&m);
    sched_getaffinity(0, sizeof(cpu_set_t), &m);
    for (int i = 0; i < max_cpus; ++i) {
        int c = (current_cpu + i + 1) % max_cpus;
        if (CPU_ISSET(c, &m)) {
            CPU_ZERO(&m);
            CPU_SET(c, &m);
            int ret;
            if ((ret = pthread_attr_setaffinity_np(&attr, sizeof(cpu_set_t), &m))) {
                fprintf(stderr, "Can't set thread affinity: %s\n", strerror(ret));
                exit(1);
            }
            current_cpu = c;
            break;
        }
    }