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Date: Wed, 30 Mar 2011 10:50:17 -0500
From: Alan Cox <alc@rice.edu>
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To: fuzhli <fuzhli1007@gmail.com>
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Cc: alc@freebsd.org, questions@freebsd.org
Subject: Re: about NKPT on amd64
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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.

Regards,
Alan