netbsd-help: Re: Questions about MSIZE, MSGBUFSIZE, NMBCLUSTERS...
Subject: Re: Questions about MSIZE, MSGBUFSIZE, NMBCLUSTERS...
To: Brian Stark
<bstark@siemens-psc.com>
From: David Brownlee
<abs@mono.org>
List: netbsd-help
Date: 11/04/1999 18:46:44
MSGBUFSIZE affects the size of the buffer used by dmesg and
friends (the kernel boot and other messages).
See options(4), or
http://www.flame.org/cgi-bin/uncgi/hman?page=options§=4
You _may_ want NMBCLUSTERS
David/absolute
On Thu, 4 Nov 1999, Brian Stark wrote:
> Hello,
>
> I need some help from someone that understands how the message buffers
> work in the kernel.
>
> I have been getting the "ENOBUFS" error message when I run some programs
> and from what I have been able to determine, I need to increase the
> amount of message buffers in my system.
>
> At this point, I'm confused and not sure what to do. In the file
> /usr/include/machine/param.h I see several constants: MSIZE, MSGBUFSIZE
> and NMBCLUSTERS, to name a few.
>
> What is the proper course of action to eliminate my ENOBUFS error message?
>
> Do I want to increase the value of MSIZE (size of an mbuf)? On NetBSD
> 1.4.1/i386 this value is 128. On an AIX 4.2 system I have access to I
> see that this value is 256.
>
> Do I need to increase the value for MSGBUFSIZE? This value is calculated
> as follows:
>
> #define PGSHIFT 12 /* LOG2(NBPG) */
> #define NBPG (1 << PGSHIFT) /* bytes/page */
> #define MSGBUFSIZE 2*NBPG /* default message buffer size */
>
> Or, should I consider increasing the NMBCLUSTERS value? In my kernel I
> have the GATEWAY option, so the value for this on my system is 512 (as
> opposed to 256 which is used for kernel's without the GATEWAY option).
>
> Do any of these values depend on how much memory my system has? In that
> case, my system has 128MB of RAM and I have 128MB of swap space.
>
>
> Brian
>
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> | Siemens PT&D, Inc. | Voice : +1 612 536-4697 |
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>