[ros-kernel] Q2 Bug (210 in bugzilla) Fix or bigger bug?

[Hartmut Birr]

> > It runs in a deadlock where one user page is switched
> > between two threads over a page in/out operations. 
> > 
> What happens in this case? Is it because there is only one 
> page still free?
> Doesn't the balancer thread kick to free memory before this point.

If an application allocates to much memory, ros starts swapping.
Currently ros uses a 2MB swap file. If the application does write to the
allocated memory, it is only possible to page out 2MB of this memory and
it is usually the first allocated and modified memory. The first
modified memory is the IAT from a dll and the relocated code section.
The read only pages are also paged out. Ros runs in an situation where
some pages are switched between two applications (explorer and an
other). I've also found two bugs. One runs in an out of memory crash
like bug #232. The other is a dead lock where a thread allocate a page
for cow and the balancer try to page out the some readonly page and
waits for pageop. I will commit a fix after some testing.

- Hartmut