This is another 4GB split patch for kernel 2.4.27.
It adds new configuration option called CONFIG_4GB.

It differs from Ingo Molnar patch in many ways and in architecture,
in way how it handles NMI issues, how it maps code, GDT, LDT and so on.
For compatibility issues it splits address space as 3:4, so user space 
applications do not see any difference in their address spaces.
In recent version of this patch I used slightly modified 
copy_{to/from}_user interface from Ingo, so these patches have something 
in common.

This patch was used in a lot of production systems with very high loads, 
so it's tested very thoroughly. Some issues/problems I found in Ingo 
patch but fixed in my one I'll post here later.

I developed this patch a year ago, but due to copyright issues I was 
unsure to post it here. Now I'm happy to contribute this code back to 
Linux community.

Kirill