Messages in this thread | | | Date | Fri, 6 Feb 2009 00:42:41 +0100 | From | Ingo Molnar <> | Subject | Re: pud_bad vs pud_bad |
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* Jeremy Fitzhardinge <jeremy@goop.org> 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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