Memoy Management

Memoy Management

[Márcio Oliveira]

Hi all,

  Somebody can help me with some memory management issues (like Out Of 
Memory) in Linux kernel 2.4 (with some backports from 2.6 kernel. eg. 
Red Hat Enterprise Kernel) and SMP machines (4 processors) with a lot of 
memory (16GB)?

Thanks a lot.

Márcio.

Re: Memoy Management

[Arjan van de Ven]

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On Wed, 2005-07-20 at 10:10 -0300, Márcio Oliveira wrote:
> Hi all,
> 
>   Somebody can help me with some memory management issues (like Out Of 
> Memory) in Linux kernel 2.4 (with some backports from 2.6 kernel. eg. 
> Red Hat Enterprise Kernel) and SMP machines (4 processors) with a lot of 
> memory (16GB)?

I'm sure RH support will be able to help you with that; I doubt many
other people care about an ancient kernel like that, and a vendor one to
boot.

(Also I assume you are using the -hugemem kernel as the documentation
recommends you to do)


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Re: Memory Management

[Márcio Oliveira]

Arjan van de Ven wrote:

>I'm sure RH support will be able to help you with that; I doubt many
>other people care about an ancient kernel like that, and a vendor one to
>boot.
>
>(Also I assume you are using the -hugemem kernel as the documentation
>recommends you to do)
>
>  
>
Arjan,

   I'd like to know/understand more about memory management  on  Linux 
Kernel and I belive this concept is applyable to the Red Hat Linux Kernel.

  I have some doubts about the ZONE divison (DMA, NORMAL, HIGHMEM), 
Shared Memory utilization, HugeTLB feature and OOM with large memory and 
the kernel management of memory on SMP machines. I believe these 
features are common to the Linux kernel in general(Red Hat, Debian, 
SuSe, kernel.org), right?
   I read a tons of docs regarding symposiums, The Linux Memory 
Management Book and lots of docs about Oracle memory management but 
memory management still not clear to me.

  If somebody can help me...

Thanks.

Re: Memory Management

[Arjan van de Ven]

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On Wed, 2005-07-20 at 11:23 -0300, Márcio Oliveira wrote:
> Arjan van de Ven wrote:
> 
> >I'm sure RH support will be able to help you with that; I doubt many
> >other people care about an ancient kernel like that, and a vendor one to
> >boot.
> >
> >(Also I assume you are using the -hugemem kernel as the documentation
> >recommends you to do)
> >
> >  
> >
> Arjan,
> 
>    I'd like to know/understand more about memory management  on  Linux 
> Kernel and I belive this concept is applyable to the Red Hat Linux Kernel.

Only on the highest of levels. The RHEL3 kernel has a VM that resembles
almost no other linux kernel in many many ways. 


>   I have some doubts about the ZONE divison (DMA, NORMAL, HIGHMEM), 
> Shared Memory utilization, HugeTLB feature and OOM with large memory and 
> the kernel management of memory on SMP machines. I believe these 
> features are common to the Linux kernel in general(Red Hat, Debian, 
> SuSe, kernel.org), right?

nope. These things are very much different between the kernels you
mention.

What do you want to use the knowledge for? Fixing the VM? Tuning your
server? The goal of your question determines what kind of answer you
want to your questions....

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Memory Management Question

[Márcio Oliveira]

Hi

Is HugeTBL proc memory parameters only to hugetlbfs "filesystem" or are 
these parameters affect ramfs, shm and tmpfs too?

What is the basic difference between ramfs, hugetlbfs, shm and tmpfs to 
the memory management / process VLM utilization?

thanks,

Márcio.