Can i allocate 4GB virtual addresses (more than a certain limit) using vmalloc?

Peter Teoh htmldeveloper at gmail.com
Tue May 31 11:27:00 EDT 2011


To answer your subject:   I think the straight answer is "no".   Many
reason, among them:

ARM is still 32-bit, at least at the present moment:

http://www.google.com/search?q=does+arm+have+64bit&num=100

so with hardware 32-bit based, doing MMU at the 64-bit level is still
not possible (without the MMU 64-bit hardware architecture, I don't
think it is possible to do any >4GB memory translation stuff.   Am I
not wrong?

On Tue, May 31, 2011 at 1:54 PM, sandeep kumar
<coolsandyforyou at gmail.com> wrote:
> Hi all,
> The following link gives the memory map for the arm architecture.
> http://www.arm.linux.org.uk/developer/memory.txt
>
> I have the following doubts..
> 1) Any chipset(based on arm) manufacturer(qualcom,samsung..) should follow
> the same memory map.
> Is it hardly constrained or can be changed?
> Where are this constraints are implemented in the kernel source tree?
>
> 2) while i was student, i read in OS concepts that, "Virtual memory gives an
> illusion to a process,
> that it has always a larger continuous address space (even more than RAM)
> available to it."
> So i thought i could allocate howmuch ever memory i want.
> But seeing the above link,i observed there is some limitation in the address
> space created by the vmalloc().
> So i m now thinking that vmalloc has some limit.
>
> Please make me clear these things....
>
>
> With regards,
> Sandeep Kumar Anantapalli,
>
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>
>



-- 
Regards,
Peter Teoh



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