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&sect=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
> 
> -------------------------------------------------------------------------
> | Brian Stark                       | Internet : bstark@siemens-psc.com |
> | Siemens PT&D, Inc.                | Voice    : +1 612 536-4697        |
> | Power Systems Control Division    | Fax      : +1 612 536-4919        |
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> 
>