Re: kern/45946: Kernel locks up in VMEM system

[Matthias Scheler <tron%zhadum.org.uk@localhost>]

The following reply was made to PR kern/45946; it has been noted by GNATS.

From: Matthias Scheler <tron%zhadum.org.uk@localhost>
To: NetBSD GNATS <gnats-bugs%NetBSD.org@localhost>
Cc: 
Subject: Re: kern/45946: Kernel locks up in VMEM system
Date: Wed, 8 Feb 2012 13:04:52 +0000

 On Wed, Feb 08, 2012 at 08:05:03AM +0000, Matthias Scheler wrote:
 >  >  can you check the version of src/sys/arch/i386/include/param.h if it
 >  >  is 1.75 because a patch sizing the arena went in 3 1/2 days ago.
 >  >  The behavior you see is that the kmem_arena runs out of space and the
 >  >  pagedaemon tries hard too free something.
 >  
 >  I'm afraid that I already have version 1.75:
 >  
 >  tron@lyssa:~>grep NetBSD /usr/src/sys/arch/i386/include/param.h 
 >  /*      $NetBSD: param.h,v 1.75 2012/02/04 17:56:16 para Exp $  */
 >  
 >  I've also tried to reduce the amount of memory of the virtual machine
 >  to 2GB and it still locked up.
 
 Lars Heidieker suggested the following change:
 
 Index: param.h
 ===================================================================
 RCS file: /cvsroot/src/sys/arch/i386/include/param.h,v
 retrieving revision 1.75
 diff -u -r1.75 param.h
 --- param.h    4 Feb 2012 17:56:16 -0000       1.75
 +++ param.h    8 Feb 2012 13:00:59 -0000
 @@ -129,7 +129,7 @@
   * logical pages.
   */
  #define       NKMEMPAGES_MIN_DEFAULT  ((8 * 1024 * 1024) >> PAGE_SHIFT)
 -#define       NKMEMPAGES_MAX_DEFAULT  ((280 * 1024 * 1024) >> PAGE_SHIFT)
 +#define       NKMEMPAGES_MAX_DEFAULT  ((360 * 1024 * 1024) >> PAGE_SHIFT)
  
  /*
   * Mach derived conversion macros
 
 This change indeed fixes the problem on my machine with 3GB and 6 cores.
 I have however no idea what the impact on different configurations in
 particukar with only little memory will be.
 
        Kind regards
 
 -- 
 Matthias Scheler                                  http://zhadum.org.uk/