Re: larger default page sizes...

[Christoph Lameter]

On Mon, 24 Mar 2008, David Miller wrote:

> From: Christoph Lameter <clameter@xxxxxxx>
> Date: Mon, 24 Mar 2008 11:27:06 -0700 (PDT)
> 
> > The move to 64k page size on IA64 is another way that this issue can
> > be addressed though.
> 
> This is such a huge mistake I wish platforms such as powerpc and IA64
> would not make such decisions so lightly.

Its certainly not a light decision if your customer tells you that the box 
is almost unusable with 16k page size. For our new 2k and 4k processor 
systems this seems to be a requirement. Customers start hacking SLES10 to 
run with 64k pages....

> The memory wastage is just rediculious.

Well yes if you would use such a box for kernel compiles and small files 
then its a bad move. However, if you have to process terabytes of data 
then this is significantly reducing the VM and I/O overhead.

> I already see several distributions moving to 64K pages for powerpc,
> so I want to nip this in the bud before this monkey-see-monkey-do
> thing gets any more out of hand.

powerpc also runs HPC codes. They certainly see the same results that we 
see.

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