Subject: Re: bufpages calculation
To: None <bjh21@cam.ac.uk,tech-kern@netbsd.org,abs@netbsd.org>
From: Ben Harris <bjh21@cam.ac.uk>
List: tech-kern
Date: 09/27/2000 12:43:17
In article <E13eFIW-0001DN-00@chiark.greenend.org.uk> you write:
>In article <Pine.NEB.4.21.0009261904010.276-100000@odysseus.mono.org> you write:
>>On Mon, 25 Sep 2000, Bill Sommerfeld wrote:
>>	Currently we calculate bufpages based on physmem. Is uvmexp.free
>>	valid at that point - if so would it make more sense to calculate
>>	buffers based on that?
>
>It looks like bufpages is currently set in allocsys(), which is called quite
>early on some architectures.  arm26 and alpha certainly call it long before
>UVM is initialised.  There's no reason for bufpages to be set this early,
>though (since actually allocating them needs UVM to be up), so it should
>perhaps go somewhere else.  main() seems like the obvious place to me.

Oops.  Of course, allocsys needs to know nbuf so it can allocate buffer
headers, and nbuf depends to some degree on bufpages, so the whole business
is less than entirely simple.

-- 
Ben Harris                                                   <bjh21@netbsd.org>
Portmaster, NetBSD/arm26               <URL:http://www.netbsd.org/Ports/arm26/>