Subject: Re: Building an alternate backing store.
To: gabriel rosenkoetter <gr@eclipsed.net>
From: Allen Briggs <briggs@ninthwonder.com>
List: tech-kern
Date: 07/13/2000 17:56:00
> Ahem. Yes, I do mean pmap_entER().

pmap_enter() is responsible for entering and changing KVA and physical
memory address mappings.  I think it's in the p.178 - 180 range of the
4.4BSD book (I was just looking at this last weekend).

> This led me to uvm_fault.c, and from there to pmap_enter(), since
> that's how uvm_fault(), the main entry point for any page fault, goes
> about getting memory pages back where they belong from wherever
> they've gone.

pmap_enter() is just used to enter the page mapping--it doesn't
actually acquire the data from wherever it's been.  If you look
around in uvm_fault(), I think you'll find that the pager (through
uobj->pgops) is responsible.

-allen