Messages in this thread | | | Date | Wed, 5 Mar 2003 05:10:56 -0800 | From | William Lee Irwin III <> | Subject | Re: High Mem Options |
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On Wed, 5 Mar 2003 04:57:47 -0800, William Lee Irwin III wrote: >> The cpu can't look at more than 4GB at a time. >> Protected mode doesn't help this, turning paging on and PAE on does. >> What it can do is point pagetables at different 4GB subsets of memory. >> c.f. kmap_atomic() for how to window around using what's actually a >> very small set of PTE's.
On Wed, Mar 05, 2003 at 02:02:57PM +0100, Michael Vergoz wrote: > Right, but if the pagetable pointing to a different 4GB subsets of > memory. The performance of the system can be disastrous, not?
Well, the TLB gets blown away at the drop of a hat. Things just have lower scaling factors with respect to memory than say, 64-bit, though Linux doesn't do anything about TLB coverage on 64-bit yet anyway.
It might be better to take this one to kernelnewbies@nl.linux.org
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