Re: [PATCH] x86: disable_mtrr_trim only need for x86_64

[Yinghai Lu]

On Jan 19, 2008 9:37 PM, H. Peter Anvin <hpa@xxxxxxxxx> wrote:
> Yinghai Lu wrote:
> > [PATCH] x86: disable_mtrr_trim only need for x86_64
> >
> > mtrr_trim_uncached_memory is only used in x86_64,
> >
> > so disable_mtrr_trim is not needed for x86_32
> >
> > Signed-off-by: Yinghai Lu <yinghai.lu@xxxxxxx>
>
> That seems like a bug, and if so this patch goes the wrong direction.
> (If the 32-bit code has another solution for the same problem, they
> should be unified.)
>
> The trimming of uncachable memory affects both 32- and 64-bit kernels;
> it's the same hardware, and even 32-bit kernels (with PAE) can access
> memory above 4 GB.
>

the trim fix for x86_64 is update end_pfn, and use that as max_pfn,
and max_low_pfn in setup_arch.

but i386 is setup_arch is only using max_low_pfn.

to make you happy, the simple way is update e820 table so code could
be unified between i386 and x86_64

update the e820 table by checking mtrr like checking gart hole...

is that OK?

YH
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