RE: [PATCH 4/4] vmm: Use a static memory map

Chen, Kenneth W
2006-10-12T21:40:25Z

Christoph Lameter wrote on Thursday, October 12, 2006 12:18 PM
> IA64 currently uses a dynamically configured memory map that is taken off
> the end of VMALLOC space. This means that we do some tweaking with some
> core constants that now refer to variables and we keep having to
> get the address of the virtual memory map and the limits from memory.
> This patch makes pfn_to_page and page_to_pfn possible without referencing
> any memory location.
>
> So, the size of the virtual memory map is always less than 8 Terabyte.
>
> I think its reasonable to take these 8 Terabyte away from the 128 Terabyte
> that we currently reserve for support for VMALLOC space.
>
> Advantages:
> - virt_to_page, page_address, pfn_to_page, page_to_pfn become simple address
> calculations without a memory reference.

I like the concept a lot.

> - This patch will enable later patches to move the virtual memory map into
> another region with a larger page size. Larger page sizes will reduce
> TLB pressure.

I like that even more, which region are you going to move it to?