vmalloc and page faults (was: memory descriptor and kernel threads)

Hi,

> ... the kernel thread is as sensitive as the kernel itself
> for the page faults. It _should not_ fault, unless ofcourse if its a
> vmalloc'ed area .. and that happens every other kernel path anyway....

I have a doubt about the vmalloc'ed memory. Is the vmalloced chunk of
memory allowed to be swapped out? Can it / Does it? My doubt arises
from the fact that the memory for the loadable modules at module load
time is allocated using vmalloc() ...

Thanks,

Rajat

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Re: vmalloc and page faults (was: memory descriptor and kernel threads)

On 4/19/07, Rajat Jain wrote:
> Hi,
>
> > ... the kernel thread is as sensitive as the kernel itself
> > for the page faults. It _should not_ fault, unless ofcourse if its a
> > vmalloc'ed area .. and that happens every other kernel path anyway....
>
> I have a doubt about the vmalloc'ed memory. Is the vmalloced chunk of
> memory allowed to be swapped out? Can it / Does it?
No, it is not swappable, you get non contigous chunks of memory
allocated using kmalloc actually. Therefore, IMHO it is not swappable.
please CMIIW.

My doubt arises
> from the fact that the memory for the loadable modules at module load
> time is allocated using vmalloc() ...
Yes, looks to me too :).But here is another question to all.
Why vmalloc is used to allocate memory for modules and not kmalloc?
Even though memory we can get using vmalloc is from a scarce pool.

TIA
~psr
>
> Thanks,
>
> Rajat
>
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> To unsubscribe from this list: send an email with
> "unsubscribe kernelnewbies" to ecartis@nl.linux.org
> Please read the FAQ at http://kernelnewbies.org/FAQ
>
>


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