Messages in this thread | | | Date | Wed, 5 Mar 2003 04:57:47 -0800 | From | William Lee Irwin III <> | Subject | Re: High Mem Options |
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On Wed, Mar 05, 2003 at 01:49:37PM +0100, Michael Vergoz wrote: > That i can't understand i when the system going to the protect mode. > How the system can use over 4GB memory ? > On freebsd, when you have over 4GB the system say "XGB of XGB skiped..." > (i'v got a machine with 8GB running on freebsd and without memory spare)
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.
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