Subject: Re: how can kernel space expand to >1GB?
To: Ming Lei <mlei@Brocade.COM>
From: Jason Thorpe <>
List: tech-kern
Date: 07/31/2003 13:08:32
On Thursday, July 31, 2003, at 09:34  AM, Ming Lei wrote:

> re a way for kernel to address larger than 1GB physical memory? I know 
> there is an option to split kernel/user space? Is this the only place 
> I need to change or there are other things need to consider? Do I need 
> to recompile any application running on top of this modified kernel? 
> Share library issues?
> On i386 platform, where is the kernel space page table that use for 
> MMU mapping? How big is the actual kernel space?
> Sorry for the bunch of questions.

NetBSD can already address more than 1G of RAM.  On the i386 port, for 
example, you can currently have up to 4G of RAM installed (usable is 
usually 3.5G).

On the i386, the kernel is limited to 1G of *virtual* memory, but that 
has nothing to do with the amount of physical memory on the system.

        -- Jason R. Thorpe <>