Re: [PATCH 1/3] x86: calculate precisely the memory needed by init_memory_mapping

From: H. Peter Anvin
Date: Mon Jun 20 2011 - 18:38:16 EST


On 06/07/2011 11:13 AM, stefano.stabellini@xxxxxxxxxxxxx wrote:
>
> - remove the extra page added on x86_32 for the fixmap because is not
> needed: the PMD entry is already allocated and contiguous for the whole
> range (a PMD page covers 4G of virtual addresses) and the pte entry is
> already allocated by early_ioremap_init.
>

Hi Stefano,

I think this is wrong. A PMD page covers *1G* of virtual addresses, and
in the 2+2 and 1+3 memory configurations, we may or may not need a
separate PMD for the fixmap.

Am I missing something?

-hpa
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