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* Demand paging - Kernel
@ 2003-03-15 16:29 Breno
  2003-03-17 14:35 ` Tommy Reynolds
  0 siblings, 1 reply; 6+ messages in thread
From: Breno @ 2003-03-15 16:29 UTC (permalink / raw)
  To: Kernel List

Hi

There is a possibility  to do demand paging in kernel space address ?


thanks




^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: Demand paging - Kernel
  2003-03-15 16:29 Demand paging - Kernel Breno
@ 2003-03-17 14:35 ` Tommy Reynolds
  2003-03-17 21:59   ` Horst von Brand
  0 siblings, 1 reply; 6+ messages in thread
From: Tommy Reynolds @ 2003-03-17 14:35 UTC (permalink / raw)
  To: Breno; +Cc: linux-kernel

Uttered "Breno" <brenosp@brasilsec.com.br>, spoke thus:

> There is a possibility  to do demand paging in kernel space address ?

No.  The entire kernel, and all  of its data structures, are resident in
memory  all of  the time.   Kernel demand  paging is  not possible,  not
necessary and not implemented.


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: Demand paging - Kernel
  2003-03-17 14:35 ` Tommy Reynolds
@ 2003-03-17 21:59   ` Horst von Brand
  2003-03-18 15:08     ` Tommy Reynolds
  0 siblings, 1 reply; 6+ messages in thread
From: Horst von Brand @ 2003-03-17 21:59 UTC (permalink / raw)
  To: Tommy Reynolds; +Cc: linux-kernel

Tommy Reynolds <reynolds@redhat.com> said:
> Uttered "Breno" <brenosp@brasilsec.com.br>, spoke thus:
> > There is a possibility  to do demand paging in kernel space address ?

> No.  The entire kernel, and all  of its data structures, are resident in
> memory  all of  the time.

In the current Linux kernel, that is.
 
>                            Kernel demand  paging is  not possible,

It is certainly possible (you could mark areas that don't contain currently
used stuff for pageout). It is extremely hairy to do right (just see the
mess with module loading/unloading, which is some of the same stuff, very
tamed).

>                                                                     not
> necessary and not implemented.

The cost of doing it right in a monolitic kernel would probably outweigh
the gains manyfold, and require massive redesign for Linux. In microkernels
it is a lot easier to do (but their performance sucks baby elephants
through straws, so they are moot :-)
-- 
Dr. Horst H. von Brand                   User #22616 counter.li.org
Departamento de Informatica                     Fono: +56 32 654431
Universidad Tecnica Federico Santa Maria              +56 32 654239
Casilla 110-V, Valparaiso, Chile                Fax:  +56 32 797513

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: Demand paging - Kernel
  2003-03-17 21:59   ` Horst von Brand
@ 2003-03-18 15:08     ` Tommy Reynolds
  0 siblings, 0 replies; 6+ messages in thread
From: Tommy Reynolds @ 2003-03-18 15:08 UTC (permalink / raw)
  To: Horst von Brand; +Cc: linux-kernel

Uttered Horst von Brand <vonbrand@inf.utfsm.cl>, spoke thus:

> Tommy Reynolds <reynolds@redhat.com> said:
> > Uttered "Breno" <brenosp@brasilsec.com.br>, spoke thus:
> > > There is a possibility  to do demand paging in kernel space address ?
> > No.  The entire kernel, and all  of its data structures, are resident in
> > memory  all of  the time.
> The cost of doing it right in a monolitic kernel would probably outweigh
> the gains manyfold, and require massive redesign for Linux. In microkernels
> it is a lot easier to do (but their performance sucks baby elephants
> through straws, so they are moot :-)

Dr. von Brand,

Thanks for  following up on  this.  You are  right, of course:  with the
source code and  enough patience anything could be  crafted.  I answered
in the sense of "is this currently implemented", and it's not ;-)


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: Demand paging - Kernel
  2003-03-16  2:11 Felipe Alfaro Solana
@ 2003-03-16 15:44 ` Breno
  0 siblings, 0 replies; 6+ messages in thread
From: Breno @ 2003-03-16 15:44 UTC (permalink / raw)
  To: Felipe Alfaro Solana, Kernel List

Hi Filipe

There is no reason , just i want know if possible.
thanks
----- Original Message -----
From: "Felipe Alfaro Solana" <felipe_alfaro@linuxmail.org>
To: "Breno" <brenosp@brasilsec.com.br>; "Kernel List"
<linux-kernel@vger.kernel.org>
Sent: Saturday, March 15, 2003 11:11 PM
Subject: Re: Demand paging - Kernel


> ----- Original Message -----
> From: "Breno" <brenosp@brasilsec.com.br>
> Date: Sat, 15 Mar 2003 13:29:52 -0300
> To: "Kernel List" <linux-kernel@vger.kernel.org>
> Subject: Demand paging - Kernel
>
> > There is a possibility  to do demand paging in kernel space address ?
>
> Why? I would like to know your reasons :-)
> --
> ______________________________________________
> http://www.linuxmail.org/
> Now with e-mail forwarding for only US$5.95/yr
>
> Powered by Outblaze


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: Demand paging - Kernel
@ 2003-03-16  2:11 Felipe Alfaro Solana
  2003-03-16 15:44 ` Breno
  0 siblings, 1 reply; 6+ messages in thread
From: Felipe Alfaro Solana @ 2003-03-16  2:11 UTC (permalink / raw)
  To: Breno, Kernel List

----- Original Message ----- 
From: "Breno" <brenosp@brasilsec.com.br> 
Date: 	Sat, 15 Mar 2003 13:29:52 -0300 
To: "Kernel List" <linux-kernel@vger.kernel.org> 
Subject: Demand paging - Kernel 
 
> There is a possibility  to do demand paging in kernel space address ? 
 
Why? I would like to know your reasons :-) 
-- 
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http://www.linuxmail.org/
Now with e-mail forwarding for only US$5.95/yr

Powered by Outblaze

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2003-03-18 14:57 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2003-03-15 16:29 Demand paging - Kernel Breno
2003-03-17 14:35 ` Tommy Reynolds
2003-03-17 21:59   ` Horst von Brand
2003-03-18 15:08     ` Tommy Reynolds
2003-03-16  2:11 Felipe Alfaro Solana
2003-03-16 15:44 ` Breno

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