4M page size

Petri Helenius pete at he.iki.fi
Mon Feb 21 07:22:02 PST 2005


Scott wrote:

> Petri Helenius wrote:
>
> FreeBSD/i386 uses 4MB pages to hold the kernel text and data, but there
> is no way (to my knowledge) to ask the pmap layer for a 4MB page after
> that either from the kernel or from userland.  However, it's also my
> understanding that most non-Xeon CPUs only have a 4kb TLB, and 4MB pages
> are just broken down into 4kb chunks for it.

Does this hold true for amd64 too?
And what does happen to the page size if the memory is mapped to 
userland? (probably 4k?)
(I assume mmap does 4k, not 4M pages?)

Pete



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