Subject: Re: pageable kernel pmap entries
To: None <>
From: Eduardo E. Horvath <>
List: tech-kern
Date: 04/30/1999 09:57:07
On Thu, 29 Apr 1999, Chuck Silvers wrote:

> the idea is that you leave as much of the cached data mapped in the kernel
> as you can, and the obvious way to do that is with pageable (ie. "non-wired")
> pmap entries.  then the mappings to cached file data compete with everything
> else for pmegs on the sun4c and sun3.  I don't know how other ports will
> want to deal with this.  pagetable-based MMUs probably don't care so much...
> the only difference there is that you could reclaim the PTPs for these
> mappings, which may not be worth it, depending on how much virtual space
> you use for the mapping cache.

Oh, good.  I thought you meant paging out the page tables (which would
probably cause some problems).  Are you using pmap_enter() or
pmap_kenter()?  I think the former should work for what you want (just
don't set the `wired' bit) but the latter probably won't.

Eduardo Horvath
	"I need to find a pithy new quote." -- me