Reducing Virtualbox CPU usage on Windows 7 guest operating system

When running Windows 7 as a guest OS on Virtualbox 5.0.16, Virtualbox would after a short while run on maximum CPU load. Looking at the Windows Task Manager it turned out that svchost.exe was running at full speed, eating up a lot of memory as well. The solution was to go to the Services tab and stop wuauserv (the Windows Update server). This would immediately bring the load down on both the guest and the host (OS X 10.11.4) operating system.

Windows Task Manager, Services tab


How to compile SimpleParse 2.1.0a1 for Python 2.6 on Windows Vista

SimpleParse is a fast Python single-pass parser generator that I use regularly. When I finally made the move onto Python 2.6 it turned out that there is no pre-compiled package for 2.6 on Windows. So, here is my procedure for compiling the source package on Windows Vista.

1. Install Cygwin if you don’t already have it on your system, and make sure that the version of Python you are installing SimpleParse for is on either the system or the Cygwin path.

2. Download and install Microsoft Visual C++ 2008 Express Edition. You should ensure that you have the latest Vista service packs installed before attempting this. If the installer quits on you then just reboot the computer and try again. Without this installed, you wil get an ‘Unable to find vcvarsall.bat’ error.

3. Download and unpack the SimpleParse 2.1.0a1 source. Using the Cygwin shell, place yourself in the root source directory.

4. If we try to run python install at this point, the Visual C++ compiler will complain:

stt/TextTools/mxTextTools/mxTextTools.c(149) : error C2133:
'mxTextSearch_Methods' : unknown size
stt/TextTools/mxTextTools/mxTextTools.c(920) : error C2133:
'mxCharSet_Methods': unknown size
stt/TextTools/mxTextTools/mxTextTools.c(2103) : error C2133:
'mxTagTable_Methods' : unknown size
error: command '"C:\Program Files\Microsoft Visual Studio 9.0\VC\BIN\cl.exe"'
failed with exit status 2

We have to add the following lines to stt/TextTools/mxTextTools/mxTextTools.c, starting at line 148 (before staticforward is used for the first time):

#ifdef _MSC_VER
#define staticforward extern

5. with is a Python 2.6 keyword, meaning it can’t be used as a variable, as is the case in the SimpleParse source code. So, we have to replace it with something else:

$ sed -r 's/with/with_t/g' < stt/TextTools/ > tmp.txt
$ cp tmp.txt stt/TextTools/

6. Finally, run python install as usual.