Hello Lateef,
Just one more question for clarification , What is the maximum amount of physical memory addressable by the kernel without making using of temporary mappings(128M)? Is it 896MB of physical RAM?
Thanks,
Thayumanavar s.
On 9/3/05, Fawad Lateef <fawadlateef@xxxxxxxxx> wrote:
On 9/3/05, Thayumanavar Sachithanantham <thayumker@xxxxxxxxx> wrote:
> Am i correct that If we have 1 G of physical RAM on our system, 128 MB will
> be reserved for temporary mappings? But this won't be used for any purpose
> since we don't need any temporary mapping(which is required for >1 GB). Then
> is it that 128 MB physical memory doesn't serve any purpose? Please clarify.
>
> Thayumanavar S.
>
The 3G/1G split is for Virtual Addresses not physical addresses. So
128MB here mentioned is for Virtual Memory not for Physical memory,
and 0 to 896MB of physical is actually directly mapped to 1G of
virtual space ((1024M - 128M) = 896MB) ........
So 128MB of Virtual Space (not physical) is always reserved by kernel
for its page tables and mapping related stuff. And almost all the
physical memory is free to be used by the processes/tasks of
user/kernel.....
--
Fawad Lateef
