About limited of process memory!

Vincent....@gmail.com

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Nov 27, 2008, 8:38:07 PM11/27/08

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I have a question.
We know that single process can't access more than 3G memory under
linux, is it means that each of parent process and child processes can
access 3G memory?
Or sum of parent process and child processes can only access 3G memory?

Ian Collins

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Nov 28, 2008, 3:50:16 AM11/28/08

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Vincent....@gmail.com wrote:
> I have a question.
> We know that single process can't access more than 3G memory under
> linux,

Says who?

--
Ian Collins

Vincent....@gmail.com

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Nov 30, 2008, 9:57:25 PM11/30/08

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On Nov 28, 4:50 pm, Ian Collins <ian-n...@hotmail.com> wrote:

I read it from network and some books, can a single process access
more than 3G memory?

Steve Watt

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Nov 30, 2008, 10:43:38 PM11/30/08

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In article <6cfb9ac9-14e6-4def...@k1g2000prb.googlegroups.com>,

Vincent....@gmail.com <Vincent....@gmail.com> wrote:
>On Nov 28, 4:50 pm, Ian Collins <ian-n...@hotmail.com> wrote:
>> Vincent.Jiang....@gmail.com wrote:
>> > I have a question.
>> > We know that single process can't access more than 3G memory under
>> > linux,
>>
>> Says who?
>

>I read it from network and some books, can a single process access
>more than 3G memory?

What architecture? Some can, some can't.
--
Steve Watt KD6GGD PP-ASEL-IA ICBM: 121W 56' 57.5" / 37N 20' 15.3"
Internet: steve @ Watt.COM Whois: SW32-ARIN
Free time? There's no such thing. It just comes in varying prices...

Vincent....@gmail.com

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Dec 1, 2008, 1:53:56 AM12/1/08

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> What architecture? Some can, some can't.
> --
> Steve Watt KD6GGD PP-ASEL-IA ICBM: 121W 56' 57.5" / 37N 20' 15.3"
> Internet: steve @ Watt.COM Whois: SW32-ARIN
> Free time? There's no such thing. It just comes in varying prices...

Redhat enterprise linux4, some of them are32bit, others are 64bit.

Michael Mol

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Dec 1, 2008, 11:39:31 AM12/1/08

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On Dec 1, 1:53 am, "Vincent.Jiang....@gmail.com"

A 32-bit x86 architecture is limited by a 32-bit address space, which
gives it about 4GB. The OS reserves about 1GB of that. On 64-bit
x86, the address space is 64 bits, which gives you an addressable
range far, far greater than 4GB.

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Vincent....@gmail.com

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Dec 1, 2008, 7:38:51 PM12/1/08

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On Dec 2, 1:20 am, Andi Kleen <frei...@alancoxonachip.com> wrote:

> Virtual address space on x86-64 is 48bits, or more accurately 2x47bits
> with a large hole in the middle. Very few 64bit architectures really
> support true 64bit virtual address space.
>
> Also early x86-64 Linux versions (e.g. RHEL4) limited the
> user addressable part of the address space to 39bits
> (512GB). In later versions it is 47bits for the user space.
>
> -Andi

Thanks a lot.
Can a single Task(Process) access more than 4GB memory on x86-64?

David Schwartz

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Dec 2, 2008, 9:16:40 AM12/2/08

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On Dec 1, 4:38 pm, "Vincent.Jiang....@gmail.com"

> Thanks a lot.
> Can a single Task(Process) access more than 4GB memory on x86-64?

There is no 4GB limit on x86-64.

DS