找出默认的pthread亲和策略，然后是Linux Kernel 2.6.32

Question

我正在尝试找出在HT系统中创建pthread时，科学Linux内核2.6.32遵循的默认亲和性策略是什么。有没有办法知道呢？在pthread创建过程中，没有调用亲和性，所以我猜亲和性留给了操作系统。

Answer 1

我不确定这是否有帮助，但下面是一些代码，它们将使用pthread API获取和设置线程亲和性：

// nail down this thread so it will only run on a specific CPU
cpu_set_t tCPUSet;
CPU_ZERO(&tCPUSet);
CPU_SET(ENCODE_LEFT_THREAD_CPU, &tCPUSet);
nReturnCode = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set_t), &tCPUSet);
if (nReturnCode == -1)  {
    pLogFile->Write(LOG_ERR, "ERROR: encodeLeftThread(): pthread_setaffinity() failed, %s, exiting thread... ", strerror(errno));
    nThreadReturnValue = THREAD_CPU_AFFINITY_ERRORS;
    pthread_exit((void *)&nThreadReturnValue);
}

CPU_ZERO(&tCPUSet);
nReturnCode = pthread_getaffinity_np(pthread_self(), sizeof(cpu_set_t), &tCPUSet);
if (nReturnCode == -1)  {
    pLogFile->Write(LOG_ERR, "ERROR: encodeLeftThread(): 2nd pthread_getaffinity() failed, %s, exiting thread... ", strerror(errno));
    nThreadReturnValue = THREAD_CPU_AFFINITY_ERRORS;
    pthread_exit((void *)&nThreadReturnValue);
}

sCPUs.clear();
sCPUs.append("    new left thread CPU affinity: ");
if (bInitLog)  {
    for (int i = 0; i < CPU_SETSIZE; i++)  {
        if (CPU_ISSET(i, &tCPUSet))  {
            sCPUs.append(" ");
            char c = '0' + i;
            sCPUs = sCPUs + c;
        }
    }
}
if (bInitLog) pLogFile->Write(LOG_DEBUG, "%s ", sCPUs.c_str());