Kernel Virtual Address Space

[Marc G. Fournier]

On Thu, 29 Jan 2004, Sridhar Chellappa wrote:

> As part of the Bootup sequence, I see create_pagetables allocate only 30
> Pages for Page Table entries in non-PAE mode and 120 pages in PAE mode.
> Does this mean that all the kernel mode entities get only 4 * 30 * 1024
> * 1024 = 120 MB worth of Address Space ? Can I tune the kernel virtual
> address space by just changing the "NKPT" define in pmap.h ?

I don't believe so ... on our servers, we set the KVA_PAGES value:

jupiter# grep KVA /etc/make.conf
CFLAGS= -O -mpentium -pipe -g -DKVA_PAGES=512
COPTFLAGS= -O -mpentium -pipe -DKVA_PAGES=512

we do it in make.conf, since doing it into the kernel config itself
doesn't propogate to various userland binaries that also need to know of
the change ...

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Marc G. Fournier           Hub.Org Networking Services (http://www.hub.org)
Email: scrappy at hub.org           Yahoo!: yscrappy              ICQ: 7615664