Re: panic in netbsd-5 (out of space in kmem_map)

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Thu, Dec 04, 2008 at 08:49:46AM -0800, Jeff Rizzo wrote:
> I got a familiar-seeming panic in a netbsd-5 system that was recently
> upgraded from 4.99.72.   It's an amd64 box, if that matters:
> 
> panic: malloc: out of space in kmem_map
> fatal breakpoint trap in supervisor mode
> trap type 1 code 0 rip ffffffff804ea125 cs 8 rflags 246 cr2 
> 7f7ffdb13064 cpl 0 rsp ffff80009fff9750
> Stopped in pid 13828.1 (raidctl) at     netbsd:breakpoint+0x5:  leave
> db{0}> bt 
> breakpoint() at netbsd:breakpoint+0x5
> panic() at netbsd:panic+0x260
> malloc() at netbsd:malloc+0x3a7
> raidioctl() at netbsd:raidioctl+0x478
> cdev_ioctl() at netbsd:cdev_ioctl+0x91
> VOP_IOCTL() at netbsd:VOP_IOCTL+0x6e
> vn_ioctl() at netbsd:vn_ioctl+0x6d
> sys_ioctl() at netbsd:sys_ioctl+0x134
> syscall() at netbsd:syscall+0xb6
> db{0}>
> 
> This is netbsd-5 from a couple weeks ago - does this look familiar to
> anyone?  It happened (I assume, due to timing) during the daily
> housekeeping (from /etc/daily).  Anything else I should be getting from
> ddb next time?
> 
> 
> Here's a dmesg in case it helps:
> booting hd0a:netbsd - starting in 0
> 9819544+478496+781792 [702096+455719]=0xcacd78
> Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
>     2006, 2007, 2008
>     The NetBSD Foundation, Inc.  All rights reserved.
> Copyright (c) 1982, 1986, 1989, 1991, 1993
>     The Regents of the University of California.  All rights reserved.
> 
> NetBSD 5.0_BETA (GENERIC) #1: Tue Nov 18 11:59:20 PST 2008
>    
> riz%colossus.corp.revision3.com@localhost:/home/riz/netbsd/src5/sys/arch/amd64/compile/obj.amd64/GENERIC
> total memory = 16382 MB
> avail memory = 15869 MB

You have too much RAM in this system :) More specifically, when the
file cache grows, it eats kmem_map entries, and the default computed
size is likely too low.
See
options NKMEMPAGES
options NKMEMPAGES_MIN
options NKMEMPAGES_MAX
in options(4). sysctl vm.nkmempages will show you the current value (I'm
not sure it's writable, unfortunably).
You may also be able to patch nkmempages with gdb without rebuilding a
new kernel.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--