Re: [Lse-tech] Re: 10.31 second kernel compile

On Sat, Mar 16, 2002 at 08:32:26PM +0100, Andi Kleen wrote:
> x86-64 aka AMD Hammer does hardware (or more likely microcode) search of 
> page tables.
> It has a 4 level page table with 4K pages. Generic Linux MM code only sees
> the first slot in 4th level page limit user space to 512GB with 3 levels. 

What about 2M pages?

> Direct mappings and kernel mappings are handled specially by architecture 
> specific code outside that first slot.
> 
> The CPU itself has I/D TLBs split into L1 and L2.

There was something in some AMD doc about preventing tlbflush on process
switch - through a context like thing perhaps? Any idea?

> 
> -Andi

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Victor Yodaiken 
Finite State Machine Labs: The RTLinux Company.
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