Subject: Re: Speeding up fork/wait path
To: David Laight <>
From: Matt Thomas <>
List: tech-kern
Date: 11/03/2003 11:49:51
On Monday, November 3, 2003, at 09:25 AM, David Laight wrote:

>> how about we extend the pool code to handle objects larger than a 
>> page?
> It would also be advantageous to allocate more than one page when
> the required item is a significatant proportion of a page.
> There is a lot of waste for anything that is between 1/2 a page and
> 2/3 a page that would be removed if two physical pages were allocated
> each time the pool needed memory.

The problem is that ports who use a PMAP_MAP_POOLPAGE need physically
contiguous pages for any multiple-page pool allocation.  UVM needs to
be able to support that better.  (UVM should be able to "steal" an
inuse unwire page that has the proper requirements to satisfy an
allocation request and remap any uses of that page to a newly allocated
free page).
Matt Thomas                     email:
3am Software Foundry              www:
Cupertino, CA              disclaimer: I avow all knowledge of this