WinDbg调试CPU占用高的问题 试验+实战 《第七篇》
时间：2022-03-10 17:12
一、High CPU试验
1、示例代码
static void Main(string[] args)
{
Console.Clear();
Console.WriteLine("到命令行下，切换到windbg目录，执行adplus -hang -pn highcpu.exe -o c:\\dumps");
Console.WriteLine("如果要停止，按Ctrl+C结束程序");
Console.WriteLine("====================================================");
while (true)
{
Console.SetCursorPosition(0, 3);
Console.Write(DateTime.Now.Ticks.ToString());
}
Console.ReadKey();
}
2、运行控制台程序后，抓取3次Dump，最好每次间隔几分钟。
3、分别对每个Dump执行如下指令。
第一个Dump: 0:000> .load clr20\sos.dll 0:000> !runaway User Mode Time Thread Time 0:334 0 days 0:00:00.468 3:dc8 0 days 0:00:00.000 2:14d0 0 days 0:00:00.000 1:750 0 days 0:00:00.000 第二个Dump: 0:000> .load clr20\sos.dll 0:000> !runaway User Mode Time Thread Time 0:334 0 days 0:00:08.221 3:dc8 0 days 0:00:00.000 2:14d0 0 days 0:00:00.000 1:750 0 days 0:00:00.000 第三个Dump: 0:000> .load clr20\sos.dll 0:000> !runaway User Mode Time Thread Time 0:334 0 days 0:00:11.559 3:dc8 0 days 0:00:00.000 2:14d0 0 days 0:00:00.000 1:750 0 days 0:00:00.000
从上面的输出可以看到，线程0的CPU时间不断增加，CPU高占用很可能是由于线程0正在执行的代码有问题造成的。
可以用!clrstack命令查看一下当前的调用堆栈以及其上的局部变量和值。
当执行!clrstack时，报出了如下提示：
0:000> !clrstack Failed to find runtime DLL (mscorwks.dll), 0x80004005 Extension commands need mscorwks.dll in order to have something to do.
这不是我想要的，加载mscorwks失败。后来经过调试发现，原来是第一步就.load时就错了，因为我的那段代码用的是vs2010。所以应该加载.net frameword 4.0。
所以，最初应该执行的.load C:/WINDOWS/Microsoft.NET/Framework/v4.0.30319/sos.dll
然后在执行!clrstack
第三个Dump
0:000> !clrstack *** ERROR: Symbol file could not be found. Defaulted to export symbols for clr.dll - PDB symbol for clr.dll not loaded OS Thread Id: 0x334 (0) Child SP IP Call Site 001cf2b8 779e70f4 [InlinedCallFrame: 001cf2b8] 001cf2b4 6a14672e *** WARNING: Unable to verify checksum for mscorlib.ni.dll DomainNeutralILStubClass.IL_STUB_PInvoke(IntPtr, COORD) 001cf2b8 6a1b6cfd [InlinedCallFrame: 001cf2b8] Microsoft.Win32.Win32Native.SetConsoleCursorPosition(IntPtr, COORD) 001cf2ec 6a1b6cfd System.Console.SetCursorPosition(Int32, Int32) 001cf324 005500bb *** WARNING: Unable to verify checksum for ConsoleApplication3.exe ConsoleApplication3.Program.Main(System.String[]) [C:\Users\ChenZhuo\documents\visual studio 2010\Projects\ConsoleApplication3\ConsoleApplication3\Program.cs @ 22] 001cf4dc 70a33e22 [GCFrame: 001cf4dc]
第二个Dump
0:000> !clrstack *** ERROR: Symbol file could not be found. Defaulted to export symbols for clr.dll - PDB symbol for clr.dll not loaded OS Thread Id: 0x334 (0) Child SP IP Call Site 001cf2b8 779e70f4 [InlinedCallFrame: 001cf2b8] 001cf2b4 6a14672e *** WARNING: Unable to verify checksum for mscorlib.ni.dll DomainNeutralILStubClass.IL_STUB_PInvoke(IntPtr, COORD) 001cf2b8 6a1b6cfd [InlinedCallFrame: 001cf2b8] Microsoft.Win32.Win32Native.SetConsoleCursorPosition(IntPtr, COORD) 001cf2ec 6a1b6cfd System.Console.SetCursorPosition(Int32, Int32) 001cf324 005500bb *** WARNING: Unable to verify checksum for ConsoleApplication3.exe ConsoleApplication3.Program.Main(System.String[]) [C:\Users\ChenZhuo\documents\visual studio 2010\Projects\ConsoleApplication3\ConsoleApplication3\Program.cs @ 22] 001cf4dc 70a33e22 [GCFrame: 001cf4dc]
第一个Dump：
0:000> !clrstack *** ERROR: Symbol file could not be found. Defaulted to export symbols for clr.dll - PDB symbol for clr.dll not loaded OS Thread Id: 0x334 (0) Child SP IP Call Site 001cf2b8 779e70f4 [InlinedCallFrame: 001cf2b8] 001cf2b4 6a14672e *** WARNING: Unable to verify checksum for mscorlib.ni.dll DomainNeutralILStubClass.IL_STUB_PInvoke(IntPtr, COORD) 001cf2b8 6a1b6cfd [InlinedCallFrame: 001cf2b8] Microsoft.Win32.Win32Native.SetConsoleCursorPosition(IntPtr, COORD) 001cf2ec 6a1b6cfd System.Console.SetCursorPosition(Int32, Int32) 001cf324 005500bb *** WARNING: Unable to verify checksum for ConsoleApplication3.exe ConsoleApplication3.Program.Main(System.String[]) [C:\Users\ChenZhuo\documents\visual studio 2010\Projects\ConsoleApplication3\ConsoleApplication3\Program.cs @ 22] 001cf4dc 70a33e22 [GCFrame: 001cf4dc]
不知道为什么，我的第三个Dump并没有出现HighCPU的提示，也许是我的电脑配置有点高吧。不过，出问题的代码已可以看得到，就在Main方法里。只需要细细查看Main方法找到问题所在就OK了。
学习自：http://www.cnblogs.com/juqiang/archive/2008/01/11/1035689.html
WinDbg调试CPU占用高的问题 试验+实战 《第七篇》,布布扣,bubuko.com
