0:000> !tp logStart: 132 logSize: 200 CPU utilization: 59 % Worker Thread: Total: 6 Running: 6 Idle: 0 MaxLimit: 10 MinLimit: 4 Work Request in Queue: 0 -------------------------------------- Number of Timers: 3 -------------------------------------- Completion Port Thread:Total: 2 Free: 2 MaxFree: 8 CurrentLimit: 2 MaxLimit: 10 MinLimit: 4虽然卦中的 CPU 不低但也不是我理想的阈值,不过分析也是可以分析的,知道了 CPU 的利用率,接下来我们看下这个 CPU 猛不猛,使用 !cpuid 看下核心数。
0:000> !cpuid CP F/M/S Manufacturer MHz 0 6,167,1 <unavailable> 199 1 6,167,1 <unavailable> 199 2 6,167,1 <unavailable> 199 3 6,167,1 <unavailable> 199只有四个核心,看样子这 CPU 不咋地哈,接下来的问题是谁导致了 CPU 爆高呢?
0:000> ~*e !clrstack ... OS Thread Id: 0x1dd8 (58) Child SP IP Call Site ... 00000065F623F360 00007ffc38383a06 xxx+c__DisplayClass18_0.b__0(System.Object) 00000065F623FA00 00007ffc385680e2 System.Threading.ThreadPoolWorkQueue.Dispatch() [/_/src/libraries/System.Private.CoreLib/src/System/Threading/ThreadPoolWorkQueue.cs @ 729] 00000065F623FA90 00007ffc9638e3ee System.Threading.PortableThreadPool+WorkerThread.WorkerThreadStart() [/_/src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.WorkerThread.cs @ 63] 00000065F623FBA0 00007ffc96372eaf System.Threading.Thread.StartCallback() [/_/src/coreclr/System.Private.CoreLib/src/System/Threading/Thread.CoreCLR.cs @ 105] 00000065F623FE30 00007ffc9730af03 [DebuggerU2MCatchHandlerFrame: 00000065f623fe30] OS Thread Id: 0x15a8 (59) Child SP IP Call Site 00000065F63BE6F8 00007ffca6905d14 [InlinedCallFrame: 00000065f63be6f8] Interop+Winsock.recv(System.Net.Sockets.SafeSocketHandle, Byte*, Int32, System.Net.Sockets.SocketFlags) 00000065F63BE6F8 00007ffc38521441 [InlinedCallFrame: 00000065f63be6f8] Interop+Winsock.recv(System.Net.Sockets.SafeSocketHandle, Byte*, Int32, System.Net.Sockets.SocketFlags) 00000065F63BE6C0 00007ffc38521441 ILStubClass.IL_STUB_PInvoke(System.Net.Sockets.SafeSocketHandle, Byte*, Int32, System.Net.Sockets.SocketFlags) 00000065F63BE790 00007ffc385679d1 System.Net.Sockets.Socket.Receive(Byte[], Int32, Int32, System.Net.Sockets.SocketFlags, System.Net.Sockets.SocketError ByRef) [/_/src/libraries/System.Net.Sockets/src/System/Net/Sockets/Socket.cs @ 1473] ... 00000065F63BF140 00007ffc3838ae0b xxx+c__DisplayClass18_0.b__0(System.Object) 00000065F63BF7E0 00007ffc385680e2 System.Threading.ThreadPoolWorkQueue.Dispatch() [/_/src/libraries/System.Private.CoreLib/src/System/Threading/ThreadPoolWorkQueue.cs @ 729] 00000065F63BF870 00007ffc9638e3ee System.Threading.PortableThreadPool+WorkerThread.WorkerThreadStart() [/_/src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.WorkerThread.cs @ 63] 00000065F63BF980 00007ffc96372eaf System.Threading.Thread.StartCallback() [/_/src/coreclr/System.Private.CoreLib/src/System/Threading/Thread.CoreCLR.cs @ 105] 00000065F63BFC10 00007ffc9730af03 [DebuggerU2MCatchHandlerFrame: 00000065f63bfc10]通过仔细观察各个线程的线程栈,发现最多的是 xxx+c__DisplayClass18_0.b__0 方法,从底层的 PortableThreadPool 来看,这是 C# 自己封装的线程池,说明这是由 线程池工作线程创建的,再辅助一张截图:
2.线程中方法时间复杂度高。
public static xxx Getxxx(xxx conxx) { xxx xxxInfo2 = conxxx; lock (xxx) { return hashxxxnfo.Where((xxxInfo x) => x.xxx == xxx.xxx && x.xxx == xxx.intPtr)?.FirstOrDefault(); } }4. 其他dump呢
0:000> !tp CPU utilization: 92% Worker Thread: Total: 16 Running: 16 Idle: 0 MaxLimit: 32767 MinLimit: 16 Work Request in Queue: 17 AsyncTimerCallbackCompletion TimerInfo@000000e644d32df0 Unknown Function: 00007fff29dc17d0 Context: 000000e136337f58 Unknown Function: 00007fff29dc17d0 Context: 000000e136344798 Unknown Function: 00007fff29dc17d0 Context: 000000e1363479a8 ... Unknown Function: 00007fff29dc17d0 Context: 000000e135730720 Unknown Function: 00007fff29dc17d0 Context: 000000e13573ccd8 -------------------------------------- Number of Timers: 0 -------------------------------------- Completion Port Thread:Total: 1 Free: 1 MaxFree: 32 CurrentLimit: 1 MaxLimit: 1000 MinLimit: 16从卦中看,cpu利用率更高,线程池队列还有任务堆积,用同样的方式也洞察出了它的问题代码,也是一个无脑丢。