svchost/msi performance issue (CPU 100%或占用过高)

症状（Symptom ）

SVCHOST CPU占用率过高，如果停止Automatic Update服务，CPU占用率高的问题消失。

或者用下面的方法确认是否AU引起SVCHOST CPU占用率过高的问题：

1. 用下面的命令行找到运行Automatic Update服务的SVCHOST进程的PID

Tasklist –m wuaueng.dll

2. 执行下面的命令行来强制客户端发起补丁检测 (某些情况下这个命令行能够重现CPU占用率过高的问题)

Wuauclt /detectnow

3. 找到运行Automatic Update服务的SVCHOST进程的PID，看它是否会引起长时间CPU占用率过高。（短时间内的CPU高是正常的）

解决方案（Solution ）

如果是AU引起SVCHOST CPU占用率过高的问题，请您参考下面的KB：

https://support.microsoft.com/kb/916089/

https://support.microsoft.com//kb/927891

您可以尝试用下面的方法看能否解决这个问题：

1. 安装更新KB927891

https://support.microsoft.com//kb/927891

2. 如果安装了更新KB927891之后，客户端仍然有持续的100%CPU问题，请您下载安装最新的WSUS 3.0 客户端：

https://download.windowsupdate.com/v7/windowsupdate/redist/standalone/WindowsUpdateAgent30-x86.exe

针对64位操作系统：

https://download.windowsupdate.com/v7/windowsupdate/redist/standalone/WindowsUpdateAgent30-x64.exe

https://download.windowsupdate.com/v7/windowsupdate/redist/standalone/WindowsUpdateAgent30-ia64.exe

上面两个步骤应该能够缓解这个问题。关于这个问题的最新的进展请参考：

https://blogs.technet.com/wsus/archive/2007/04/28/update-on.aspx

Source: Samuel Lv Email

更新的解决办法：

The 2 updates (KB927891and WUA3.0 )to resolve AU related SVCHOST high CPU issue are available on WSUS now.

KB927891 is available on WindowsUpdate /WSUS. It is listed as Critical Updates in WSUS. Please refer to:
https://blogs.technet.com/wsus/archive/2007/05/22/latest-msi-dll-fix-927891-also-available-to-wu-wsus-today.aspx

KB936301 is listed in WSUS as Critical Updates. It is to install on WSUS 2.0 SP1 server to upgrade Selfupdate tree to “WSUS 3.0” but keep the server as WSUS 2.0, so that client can get WUA3.0 by visiting WSUS selfupdate tree. Please refer to:
https://blogs.technet.com/wsus/archive/2007/05/22/updates-for-wsus-available-today.aspx