Set:-

    cpu_set_t mask;
    CPU_ZERO(&mask);
    pid_t pid = gettid(); // Thread. For pid, use getpid()

    CPU_SET(1, &mask);
    if(sched_setaffinity(pid, sizeof(mask), &mask) == -1) {
	    LOGE("set affinity failed, cpu: 1");
    }

    //int syscallres = syscall(__NR_sched_setaffinity, pid, sizeof(mask), &mask);
    //if (syscallres)
    //{
    //    err = errno;
    //    LOGE("Error in the syscall setaffinity: mask=%d=0x%x err=%d=0x%x", mask, mask, err, err);
    //}

Get :-

    cpu_set_t get;
    CPU_ZERO(&get);
    if (sched_getaffinity(0, sizeof(get), &get) == -1)
    {
    	LOGE("warning: cound not get thread affinity, continuing...");
    }