about NKPT on amd64

Alan Cox alc at rice.edu
Wed Mar 30 16:10:06 UTC 2011

On 03/30/2011 01:47, fuzhli wrote:
> Hi, Alan
> I'm study the "Revision 187465" : "Prepare for a larger kernel virtual
> address space". After read some relative source code, I have an
> question about the macro NKPT on amd64: why 32 is enough for the
> kernel page table pages? Do it means that the range (KERNBASE,
> virtual_avail) should always less than 64MB( 32 * 2MB)?

NKPT sets the size of the kernel page table during the earliest part of
the kernel's initialization. After that, the size of the page table
grows dynamically according to usage.


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