Re: pud_bad vs pud_bad

[Ingo Molnar]

* Jeremy Fitzhardinge <jeremy@xxxxxxxx> wrote:

> Ingo Molnar wrote:
>> We'd also lose a fair bit of performance (not to mention the pagetable  
>> footprint doubling that Hugh already mentioned) on 32-bit PAE capable  
>> systems that dont actually have RAM above 4G physical.
>
> Why's that?  Do you mean directly from using PAE, or as a side-effect of 
> highmem?

just the act of using PAE was measured to cause multi-percent slowdown in 
fork() and exec() latencies, etc. The pagetables are twice as large so is 
that really surprising?

	Ingo
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