如何让程序运行在所有CPU核心上

先解释几个概念：多CPU，多核，超线程

多CPU：（一台主机的）主板上有多个CPU。

多核：一个CPU有多个核心（下图是6个物理核心）。

超线程：CPU有一个重要的参数是某个型号的CPU是否支持超线程。例如，某个CPU有4个物理核心，它支持超线程技术，那么在逻辑上可以看作8个核心（也叫4核8线程）。比如我们在中关村在线上看到某款CPU的参数如下：

表明这款CPU是支持超线程技术的。

在Windows系统下如何设置一个进程能在所有的（逻辑）核心上执行呢？

方法一：在任务管理器中设置进程的相关性。

方法二：在C#中Environment.ProcessorCount可以得到当前CPU的所有逻辑核心。

   static void SetProcessorAffinity()
        {
            pfcLogger logger = new pfcLogger();

            try
            {             
                Process proc = Process.GetCurrentProcess();
                long affinitymask = (long)proc.ProcessorAffinity;

                switch (Environment.ProcessorCount)
                {
                    //Environment.ProcessorCount includes any hyperthreaded processors

                    case 2: affinitymask = 0x0003; break;  // number of logical processors: 2
                    case 4: affinitymask = 0x000F; break;  // number of logical processors: 4
                    case 8: affinitymask = 0x00FF; break;  // number of logical processors: 8
                    case 12: affinitymask = 0x0FFF; break;  // number of logical processors: 12
                    case 16: affinitymask = 0xFFFF; break;  // number of logical processors: 16
                    default: break;                         // keep its default processorAffinity
                }
                proc.ProcessorAffinity = (IntPtr)affinitymask;
            }
            catch (System.ComponentModel.Win32Exception cwe)
            {
                MessageBox.Show("Fail to set processor affinity attribute. " + cwe.Message);
                logger.Error(DateTime.Now, null, "PackOne.Server.Startup.Program", MethodBase.GetCurrentMethod().Name, cwe);
            }
            catch (System.NotSupportedException nse)
            {
                MessageBox.Show("Fail to set processor affinity attribute. " + nse.Message);
                logger.Error(DateTime.Now, null, "PackOne.Server.Startup.Program", MethodBase.GetCurrentMethod().Name, nse);
            }
            catch (System.InvalidOperationException ioe)
            {
                MessageBox.Show("Fail to set processor affinity attribute. " + ioe.Message);
                logger.Error(DateTime.Now, null, "PackOne.Server.Startup.Program", MethodBase.GetCurrentMethod().Name, ioe);
            }
            catch (Exception e)
            {
                MessageBox.Show("Fail to set processor affinity attribute. " + e.Message);
                logger.Error(DateTime.Now, null, "PackOne.Server.Startup.Program", MethodBase.GetCurrentMethod().Name, e);
            }
        }

说明：上面的代码的关键部分是这样：

                Process proc = Process.GetCurrentProcess();
                long affinitymask = (long)proc.ProcessorAffinity;

                switch (Environment.ProcessorCount)
                {
                    //Environment.ProcessorCount includes any hyperthreaded processors

                    case 2: affinitymask = 0x0003; break;  // number of logical processors: 2
                    case 4: affinitymask = 0x000F; break;  // number of logical processors: 4
                    case 8: affinitymask = 0x00FF; break;  // number of logical processors: 8
                    case 12: affinitymask = 0x0FFF; break;  // number of logical processors: 12
                    case 16: affinitymask = 0xFFFF; break;  // number of logical processors: 16
                    default: break;                         // keep its default processorAffinity
                }
                proc.ProcessorAffinity = (IntPtr)affinitymask;

其他代码是用于写日志和异常处理的。

另外，如何在windows上查看某个CPU的物理核心和逻辑核心呢？

使用命令：WMIC CPU Get DeviceID,NumberOfCores,NumberOfLogicalProcessors

 如果NumberOfCores = NumberOfLogicalProcessors ,则表明该CPU不支持超线程。