先解釋幾個概念：多CPU，多核，超線程
多CPU：（一台主機的）主板上有多個CPU。
多核：一個CPU有多個核心（下圖是6個物理核心）。
超線程：CPU有一個重要的參數是某個型號的CPU是否支持超線程。例如，某個CPU有4個物理核心，它支持超線程技術，那么在邏輯上可以看作8個核心（也叫4核8線程）。比如我們在中關村在線上看到某款CPU的參數如下：
表明這款CPU是支持超線程技術的。
在Windows系統下如何設置一個進程能在所有的（邏輯）核心上執行呢？
方法一：在任務管理器中設置進程的相關性。
方法二：在C#中Environment.ProcessorCount可以得到當前CPU的所有邏輯核心。
1 static void SetProcessorAffinity() 2 { 3 pfcLogger logger = new pfcLogger(); 4 5 try 6 { 7 Process proc = Process.GetCurrentProcess(); 8 long affinitymask = (long)proc.ProcessorAffinity; 9 10 switch (Environment.ProcessorCount) 11 { 12 //Environment.ProcessorCount includes any hyperthreaded processors 13 14 case 2: affinitymask = 0x0003; break; // number of logical processors: 2 15 case 4: affinitymask = 0x000F; break; // number of logical processors: 4 16 case 8: affinitymask = 0x00FF; break; // number of logical processors: 8 17 case 12: affinitymask = 0x0FFF; break; // number of logical processors: 12 18 case 16: affinitymask = 0xFFFF; break; // number of logical processors: 16 19 default: break; // keep its default processorAffinity 20 } 21 proc.ProcessorAffinity = (IntPtr)affinitymask; 22 } 23 catch (System.ComponentModel.Win32Exception cwe) 24 { 25 MessageBox.Show("Fail to set processor affinity attribute. " + cwe.Message); 26 logger.Error(DateTime.Now, null, "PackOne.Server.Startup.Program", MethodBase.GetCurrentMethod().Name, cwe); 27 } 28 catch (System.NotSupportedException nse) 29 { 30 MessageBox.Show("Fail to set processor affinity attribute. " + nse.Message); 31 logger.Error(DateTime.Now, null, "PackOne.Server.Startup.Program", MethodBase.GetCurrentMethod().Name, nse); 32 } 33 catch (System.InvalidOperationException ioe) 34 { 35 MessageBox.Show("Fail to set processor affinity attribute. " + ioe.Message); 36 logger.Error(DateTime.Now, null, "PackOne.Server.Startup.Program", MethodBase.GetCurrentMethod().Name, ioe); 37 } 38 catch (Exception e) 39 { 40 MessageBox.Show("Fail to set processor affinity attribute. " + e.Message); 41 logger.Error(DateTime.Now, null, "PackOne.Server.Startup.Program", MethodBase.GetCurrentMethod().Name, e); 42 } 43 }
說明：上面的代碼的關鍵部分是這樣：
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;
其他代碼是用於寫日志和異常處理的。
另外，如何在windows上查看某個CPU的物理核心和邏輯核心呢？
使用命令：WMIC CPU Get DeviceID,NumberOfCores,NumberOfLogicalProcessors
如果NumberOfCores = NumberOfLogicalProcessors ,則表明該CPU不支持超線程。