The following reply was made to PR bin/29774; it has been noted by GNATS.

From: Manuel Bouyer <bouyer@antioche.eu.org>
To: gnats-bugs@NetBSD.org
Cc: gnats-admin@NetBSD.org, netbsd-bugs@NetBSD.org
Subject: Re: bin/29774: sysctl can't raise kern.mbuf.nmbclusters
Date: Wed, 23 Mar 2005 19:49:35 +0100

 --k+w/mQv8wyuph6w0
 Content-Type: text/plain; charset=us-ascii
 Content-Disposition: inline
 
 On Wed, Mar 23, 2005 at 05:39:00PM +0000, tecneeq@tecneeq.de wrote:
 > Architecture: i386
 > Machine: i386
 > >Description:
 >   I try to raise kern.mbuf.nmbclusters from 1024 to 2048 wich,
 >   according to the manpage, should be possible. It is not.
 
 sysctl(3) says:
              MBUF_NMBCLUSTERS
 		The limit on the number of mbuf clusters.  The variable
 		can only be increased, and only increased on machines
 		with direct-mapped pool pages
 
 So it's not supposed to work on all machines, and i386 doesn't have
 direct-mapped pool pages. It's a bug in sysctl(8).
 How to document it in sysctl(8) ? Change "raise only" to "machine dependant" ?
 
 
 -- 
 Manuel Bouyer <bouyer@antioche.eu.org>
      NetBSD: 26 ans d'experience feront toujours la difference
 --
 
 --k+w/mQv8wyuph6w0
 Content-Type: text/plain; charset=us-ascii
 Content-Disposition: attachment; filename=diff
 
 Index: sysctl.8
 ===================================================================
 RCS file: /cvsroot/src/sbin/sysctl/sysctl.8,v
 retrieving revision 1.117
 diff -u -r1.117 sysctl.8
 --- sysctl.8	21 Nov 2004 22:18:10 -0000	1.117
 +++ sysctl.8	23 Mar 2005 18:49:29 -0000
 @@ -254,7 +254,7 @@
  .Xr sysctl 3 .
  The changeable column indicates whether a process with appropriate
  privilege can change the value.
 -.Bl -column proc.xpidx.rlimit.coredumpsize.hardxxxxxx integerxxx
 +.Bl -column proc.xpidx.rlimit.coredumpsize.hardxxxx integerx
  .It Sy Name	Type	Changeable
  .It ddb.fromconsole	integer 	yes
  .It ddb.lines	integer	yes
 @@ -317,7 +317,7 @@
  .It kern.mbuf.mcllowat	integer	yes
  .It kern.mbuf.mclsize	integer	no
  .It kern.mbuf.msize	integer	no
 -.It kern.mbuf.nmbclusters	integer	raise only
 +.It kern.mbuf.nmbclusters	integer	machine dependant
  .It kern.monotonic_clock	integer	no
  .It kern.msgbuf	struct	no
  .It kern.msgbufsize	integer	no
 
 --k+w/mQv8wyuph6w0--