[gentoo-user] What is HIGHPTE option in kernel?

[gentoo-user] What is HIGHPTE option in kernel?

[Ow Mun Heng]

[quote]
Allocate 3rd-level pagetables from highmem (HIGHPTE)

The VM uses one page table entry for each page of physical memory.
For systems with a lot of RAM, this can be wasteful of precious
low memory. Setting this option will put user-space page table
entries in high memory.
[/quote]

I have 1.5Gb of RAM, will this be useful for me?

-- 
Ow Mun Heng
Gentoo/Linux on DELL D600 1.4Ghz 1.5GB RAM
98% Microsoft(tm) Free!! 
Neuromancer 23:23:18 up 3:33, 5 users, load average: 0.20, 0.70, 1.11 


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Re: [gentoo-user] What is HIGHPTE option in kernel?

[Bastian Balthazar Bux]

Ow Mun Heng wrote:
> [quote]
> Allocate 3rd-level pagetables from highmem (HIGHPTE)
> 
> The VM uses one page table entry for each page of physical memory.
> For systems with a lot of RAM, this can be wasteful of precious
> low memory. Setting this option will put user-space page table
> entries in high memory.
> [/quote]
> 
> I have 1.5Gb of RAM, will this be useful for me?
> 
Not sure but:
3rd-level pagetables are for systems with a *lot* of memory that don't
want to waste space in the lowest gig of mem (to keep addresses of high
mem.).

So basically no advantage with 1.5 gig

Cheers
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Re: [gentoo-user] What is HIGHPTE option in kernel?

[Frank Schafer]

On Wed, 2005-08-31 at 23:23 +0800, Ow Mun Heng wrote:
> [quote]
> Allocate 3rd-level pagetables from highmem (HIGHPTE)
> 
> The VM uses one page table entry for each page of physical memory.
> For systems with a lot of RAM, this can be wasteful of precious
> low memory. Setting this option will put user-space page table
> entries in high memory.
> [/quote]
> 
> I have 1.5Gb of RAM, will this be useful for me?
> 
> -- 
> Ow Mun Heng
> Gentoo/Linux on DELL D600 1.4Ghz 1.5GB RAM
> 98% Microsoft(tm) Free!! 
> Neuromancer 23:23:18 up 3:33, 5 users, load average: 0.20, 0.70, 1.11 
> 
> 

No
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Re: [gentoo-user] What is HIGHPTE option in kernel?

[Ow Mun Heng]

On Wed, 2005-08-31 at 20:32 +0200, Bastian Balthazar Bux wrote:
> Ow Mun Heng wrote:
> > [quote]
> > Allocate 3rd-level pagetables from highmem (HIGHPTE)
> > 
> > The VM uses one page table entry for each page of physical memory.
> > For systems with a lot of RAM, this can be wasteful of precious
> > low memory. Setting this option will put user-space page table
> > entries in high memory.
> > [/quote]
> > 
> > I have 1.5Gb of RAM, will this be useful for me?
> > 
> Not sure but:
> 3rd-level pagetables are for systems with a *lot* of memory that don't
> want to waste space in the lowest gig of mem (to keep addresses of high
> mem.).
> 
> So basically no advantage with 1.5 gig

Ah.. I see. Thanks.

(as it turns out, seems like my make oldconfig wasn't really using the
old config. I had many iterations of my kernel being compiled with diff
stuffs. Finally found that the 4GB option wasn't turned 'on')

/me wonders when I will have >4GB of ram and load everything into RAM
(and XFS filesystems). Can you say Super TUX? hehe..

-- 
Ow Mun Heng
Gentoo/Linux on DELL D600 1.4Ghz 1.5GB RAM
98% Microsoft(tm) Free!! 
Neuromancer 09:53:42 up 11:52, 5 users, load average: 0.74, 1.25, 2.45 


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