*BSD News Article 23428


Return to BSD News archive

Newsgroups: comp.os.386bsd.bugs
Path: sserve!newshost.anu.edu.au!munnari.oz.au!constellation!convex!convex!cs.utexas.edu!swrinde!gatech!howland.reston.ans.net!noc.near.net!lynx!random.ccs.northeastern.edu!news
From: jtsilla@merrimack.ccs.northeastern.edu (James Tsillas)
Subject: Re: [FreeBSD 1.0e] Kernel's bss has grown up
In-Reply-To: wollman@aix1.emba.uvm.edu's message of Sun, 7 Nov 1993 10: 14:16 GMT
Message-ID: <JTSILLA.93Nov7094722@merrimack.ccs.northeastern.edu>
Sender: news@random.ccs.northeastern.edu
Nntp-Posting-Host: merrimack.ccs.neu.edu
Organization: College of CS, Northeastern University
References: <2bd92f$4t@keltia.frmug.fr.net> <MYCROFT.93Nov6093036@duality.gnu.ai.mit.edu>
	<1993Nov7.101416.26351@emba.uvm.edu>
Date: Sun, 7 Nov 1993 14:47:22 GMT
Lines: 62


Speaking of buffer allocation.. why is there a limit in the number of
allocatable buffers in NetBSD 0.9? I have a machine with lots of memory
and would like to allocate 2 MB or more to buffer via a -DBUFPAGES=xxxx
in my param flags. This seems to work up to a point but is limited by
the following line in arch/i386/i386/machdep.c:

bufpages = min(NKMEMCLUSTERS*2/5, bufpages);  /* XXX ? - cgd */

I've since commented out this line to get my big buffer cache (and, I
think, smoother performance) without any visible trouble.

Incidently, NKMEMCLUSTERS seems to be a fixed value regardless of how
much memory you running.

Now, while on the subject.. does NetBSD 0.9 support >16 MB memories
using DMA controllers such as Adaptec.

thanks,
-Jim.



In article <1993Nov7.101416.26351@emba.uvm.edu> wollman@aix1.emba.uvm.edu (Garrett Wollman) writes:

   Newsgroups: comp.os.386bsd.bugs
   Path: random.ccs.northeastern.edu!lynx!noc.near.net!howland.reston.ans.net!europa.eng.gtefsd.com!uunet!emba-news.uvm.edu!aix1.emba.uvm.edu!wollman
   From: wollman@aix1.emba.uvm.edu (Garrett Wollman)
   Sender: news@emba.uvm.edu
   Organization: University of Vermont, EMBA Computer Facility
   References: <2bd92f$4t@keltia.frmug.fr.net> <MYCROFT.93Nov6093036@duality.gnu.ai.mit.edu>
   Date: Sun, 7 Nov 1993 10:14:16 GMT
   Lines: 23

   [Bogus `world' distribution deleted.]

   In article <MYCROFT.93Nov6093036@duality.gnu.ai.mit.edu>,
   Charles Hannum <mycroft@duality.gnu.ai.mit.edu> wrote:
   >Out of curiosity, I looked, and that claim is *not* true, except for a
   >very twisted sense of what the word `dynamic' means.

   To be completely precise, our use of the word ``dynamic'' refers to
   the fact that, while virtual address space for buffers is still
   statically allocated, the amount of space made available for this
   purpose depends on the size of main memory, and will never exceed
   (32MB)*2/5 in the present implementation.  This compares to various
   incarnations of 386BSD in which either a ridiculously small number of
   fixed-size buffers were allocated, or buffer allocation was permitted
   to use up all of available memory.

   -GAWollman

   -- 
   Garrett A. Wollman   | Shashish is simple, it's discreet, it's brief. ... 
   wollman@emba.uvm.edu | Shashish is the bonding of hearts in spite of distance.
   uvm-gen!wollman      | It is a bond more powerful than absence.  We like people
   UVM disagrees.       | who like Shashish.  - Claude McKenzie + Florent Vollant
--
	***         James Tsillas  jtsilla@ccs.neu.edu           ***
	***      Work: (508)898-2800, Home: (617)641-0513        ***
	***        "He is after me. Jim is after him."           ***
	***            - Hop on Pop, Dr. Seuss                   ***