Bigphysarea patch and 2.6, advice requested

[Terrence Martin <tmartin@physics.ucsd.edu>]

Hi,

I have been asked to investigate the 2.6 kernel for a high performance 
computing application. One of the questions we have is whether or not 
2.6 supports the so called "bigphysarea" patch, or "hack" as it is 
sometimes referred to or has some built in mechanism to accomplish the 
same ends, large contiguous blocks of memory suitable for DMA.

The problem is that the project would like to use large contiguous areas 
of memory for the purposes of DMA for various custom made PCI cards. I 
have read in a couple of posts that when the PCI device supports 
scatter/gather that is the preferred mechanism. The issue is that there 
is a very good chance that not all of the devices have the 
scatter/gather mechanism implemented on board.

Is there anything in 2.6 that accomplishes the same ends as the 2.4 
based bigphysarea patch/hack?  What are other people doing when they 
need this functionality and also want to run 2.6?

Thanks for any insight you can provide.

Terrence Martin
UCSD Physics