Re: ZONE_HIGHMEM > 896MB x86 32-bit

On 5/23/06, Abhishek Singh <abhishek.singh.kumar@xxxxxxxxx> wrote:
> Hi,
>
>     I am trying to understand how linux handles memory management on
> 32-bit x86. I came to know about ZONE_HIGHMEM (Memory which is not
> directly mapped by the kernel (> 896MB) ).
>
>     I am not able to get any reference for from where this limit of
> 896 MB came from.
>
>     I would be glad if somebody could explain why is this limit of 896
> MB fixed and refernces to it.
>
> Thanks in addvance,
>
> Abhishek
Check out http://kerneltrap.org/node/2450 for the answer to your question.
Quick answer is 896MB = 1 GB - 128 MB

1G and 128 MB are a part of the Linux VM design

Balbir