Re: [PATCH] x86: mtrr cleanup for converting continuous to discrete- auto detect v2

[H. Peter Anvin]

Yinghai Lu wrote:
> On Thu, May 1, 2008 at 12:42 PM, H. Peter Anvin <hpa@xxxxxxxxx> wrote:
> > Yinghai Lu wrote:
> >
> > > loop mtrr chunk_size and gran_size from 1M to 2G to find out optimal
> > value.
> >  Why stopping at 2 GB?
>
> if you select 4g for chunk size, we don't need to convert that from
> continuous to discrete to make X server driver happen.
>
> actually the code could support any chunk_size...
>
> for example: 16 g system
> orginal:
> 0-4g WB
> 3.5g-4g UC
> 4g-8g WB
> 8g-16g WB
> 16g-16.5g WB
>
> if you set chunk size to 16g, and gran size <= 512M
> you will get
> 0-16g WB
> 3.5g-4g UC
> 16g-16.5g WB

Yes, 16 GB systems are already mainstream; 32 GB is common, so I don't 
see any reason to stop at 2 GB.  Instead, it should loop up to the 
physical address size.

	-hpa
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