Regarding remap_pfn_page

[mindentropy]

>So your question is rather more confined : Whether you can allocate
>physically cotigous memory of 16MB, right? Mapping is not an issue
>here. proper error handling will anyways tell you whether you
>succeeded or not. I think with kmalloc, you may not get memory larger
>than 4MB.

Yes mapping was never an issue. Contiguous physical frames is an issue. 
kmalloc limitation is 128KB. __get_page_frames  with order higher that 10 
would have higher chances of failing. I guess I need to grab as much 
contiguous memory as possible during boot time. My /proc/buddyinfo on a 512MB 
RAM machine paints a depressing picture of contiguous chunks.