For the longest time I have been fighting what to do with machines that have 4GB or more of memory and large memory mapped I/O resources. As the conflict in memory space can cause a loss of 1/2GB of memory. Which does not tend to be good for performance.
Looking the large memory mapped I/O resources all have 64bit BARs. So I am just going to modify the LinuxBIOS resource allocator to put 64bit BARs on x86-64 boxes at least above the top of memory.
There are a couple of short term hacks that I can do with relocating memory but on the Opteron the more memory I add the more problems I run into. And moving BARS above 4G looks like the right term fix.
Any objections?
Eric