ID Number: Q70800
3.00
WINDOWS
buglist3.00 fixlist3.10
Summary:
PROBLEM ID: WIN9103008
SYMPTOMS
Running an application under the Microsoft Windows debugging kernel
causes a FatalExit message "free memory overwrite at y:x" to appear
on the debugging monitor or terminal.
CAUSE
For performance reasons, when an application releases a memory page
that was previously on the kernel free page list, Windows does not
write the kernel's memory test pattern back into the freed memory.
The kernel interprets this as a problem with the application.
RESOLUTION
Microsoft has confirmed this to be a problem in Windows version
3.0. Two ways to avoid this problem are as follows:
- During the debugging phase of application development, turn off
paging by setting Paging=0 in the [386enh] section of the
SYSTEM.INI file. Changing this setting negatively impacts system
performance.
- Modify the [kernel] section of the WIN.INI file to set
EnableFreeChecking=0.
This problem was corrected in Windows version 3.1.
Additional reference words: 3.00