Re: process page tables

["rahul s" <son.r.rahul@xxxxxxxxx>]

Thanks for all the quick responses.


That clears my doubts.


-Rahul

On 10/16/07, Jacky(GuangXiang Lee) <gxli@xxxxxxxxxxx> wrote:

 

----- Original Message -----

From: 李一

To: Mulyadi Santosa

Cc: kernelnewbies@xxxxxxxxxxxx

Sent: Tuesday, October 16, 2007 2:00 PM

Subject: Re: process page tables

On 10/16/07, Mulyadi Santosa <mulyadi.santosa@xxxxxxxxx> wrote:

Hi...
> I am new to Linux MM. Can someone answer my following questions?
>
I'll try...
> 1> Where is the process page table(mm->pgd) stored? Is it stored below
> PAGE_OFFSET ?

not true. when forking a new process, several pages include pgd will be allocated from kernel cache in kernel space.then above PAGE_OFFSET.

Above PAGE_OFFSET, in other word... it's inside kernel space, just like
the task_struct descriptor.

sure
>  If yes, then wouldn't there
> be a chance of the page tables getting accidentally corrupted by the user
> process as it is in the user address space?
>

yes these pages should not be movable(swapped out).
> 2> What will happen if the page containing the process page table(mm->pgd)
> is swapped on the disk and the process is scheduled for execution ?
>
Since it's in kernel space, it won't be swapped out.

sure

Why wouldn't things in kernel space be swapped out? Dosen't make sense...

regards,

Mulyadi


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