On Thu, Jul 16, 2009 at 7:11 PM, vikesh u <[email protected]> wrote:

> hi,
>   " Every logical address in kernel mode is kernel virtual address but
> every kernel virtual address may not be a logical address."  famous saying
> [?]
>
>     I read LDD3 and understood that kernel logical address(KLA) is that
> kernel is ready to map now..i.e page to frame mapping is present already in
> RAM(i.e page tables..It is said to be built at boot time) for the memory
> less than equal to 896.
>
> For some thing above 896  there is no mapping .
>
> Now the high memory address are not directly mapped in (above the 896
> MB), kernel has to make page table for them in order to make available
> them, these addresses are called logical address. alloc_pages(..) can
> returns those address. Internally kernel makes use of kmap(..) &
> kunmap(..) to map them.


Hello Folks,

me and one of my friend have been little tossed out over the logical and
virtual address of the kernel and in the kernel mode . So he has come up
with  the above explanation . Correct us if we are wrong  ?




-- 
Regards,
~Sid~

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