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From: htmldeveloper@gmail.com (Peter Teoh)
To: kernelnewbies@lists.kernelnewbies.org
Subject: Can i allocate 4GB virtual addresses (more than a certain limit) using vmalloc?
Date: Tue, 31 May 2011 23:27:00 +0800	[thread overview]
Message-ID: <BANLkTiktzP4PmYdbSyKY8F_a0hhEfUzZZQ@mail.gmail.com> (raw)
In-Reply-To: <BANLkTikCwSmk5SuCVmhCzyKM9dQeWY8MVw@mail.gmail.com>

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@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,
>
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies at kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>
>



-- 
Regards,
Peter Teoh

  parent reply	other threads:[~2011-05-31 15:27 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-05-31  5:54 Can i allocate 4GB virtual addresses (more than a certain limit) using vmalloc? sandeep kumar
2011-05-31  7:02 ` Mulyadi Santosa
2011-05-31  8:09   ` sandeep kumar
2011-05-31 15:19 ` Dave Hylands
2011-08-22 21:43   ` subin gangadharan
2011-08-22 22:27     ` Jonathan Neuschäfer
2011-05-31 15:27 ` Peter Teoh [this message]
2011-06-01  4:24   ` sandeep kumar

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