kern/39251: panic: kernel diagnostic assertion "anon->an_ref == 0"

[Bernd Ernesti <pr200807%veego.de@localhost>]

>Number:         39251
>Category:       kern
>Synopsis:       panic: kernel diagnostic assertion "anon->an_ref == 0"
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Jul 30 06:30:00 +0000 2008
>Originator:     Bernd Ernesti
>Release:        NetBSD 4.99.71
>Organization:
>Environment:
        
        
System: NetBSD arresum.veego.de 4.99.71
Source: 29-07-2008 21:00 UTC
Architecture: i386
Machine: i386
CPU: AMD 4600+ X2 in SMP mode
>Description:
        The kernel panics with:

panic: kernel diagnostic assertion "anon->an_ref == 0" failed: file 
"/src/sys/uvm/uvm_anon.c", line 107
fatal breakpoint trap in supervisor mode
trap type 1 code 0 eip c051035c cs 8 eflags 246 cr2 b96ed000 ilevel 0
Stopped in pid 19724.1 (cc1plus) at     netbsd:breakpoint+0x4:  popl    %ebp

db{0}> mach cpu 0
using CPU 0
db{0}> bt
breakpoint(c0840833,d06c4af8,c08a4040,c090e400,c090e280,0,d06c4b0c,c044f79f,c090e3cc,d8f0ab00)
 at netbsd:breakpoint+0x4
panic(c088d1a8,c07e6bdd,c0820452,c0820431,6b,0,d06c4b2c,c03c147c,c07e6bdd,c0820431)
 at netbsd:panic+0x1b8
__kernassert(c07e6bdd,c0820431,6b,c0820452,0,0,d06c4b6c,c03c4c0d,d8450630,d03bfbf0)
 at netbsd:__kernassert+0x39
uvm_analloc(d8450630,d03bfbf0,d06c4b6c,c03be5f0,d8450630,d06e44e0,0,d06c4c70,d8450630,0)
 at netbsd:uvm_analloc+0x7c
uvmfault_promote(d06c4c98,d06c4c90,0,6,22,d06c4cc8,1000000,0,ffffffff,ffffffff) 
at netbsd:uvmfault_promote+0x16d
uvm_fault_internal(d062d008,b96ed000,2,0,3,b9300000,d06c4cdc,0,d06e44e0,c089dffc)
 at netbsd:uvm_fault_internal+0xb14
trap() at netbsd:trap+0x734
--- trap (number 6) ---
0xbbbc5614:
db{0}> show reg
ds          0x10
es          0x10
fs          0x30
gs          0x10
edi         0
esi         0xc088d1a8  copyright+0xa7348
ebp         0xd06c4aac
ebx         0x100
edx         0x8
ecx         0
eax         0x1
eip         0xc051035c  breakpoint+0x4
cs          0x8
eflags      0x246
esp         0xd06c4aac
ss          0x10
netbsd:breakpoint+0x4:  popl    %ebp

db{0}> mach cpu 1
using CPU 1
db{0}> bt
x86_stihlt(cc1ca280,0,0,0,0,0,c2f2e048,40,ce96fda0,c08a4ed8) at 
netbsd:x86_stihlt+0x5
idle_loop(0,c0419e20,cc1ca280,c01002d0,0,c01002cd,0,c01002cd,0,0) at 
netbsd:idle_loop+0x176
Bad frame pointer: 
db{0}> show reg 
ds          0x10
es          0x10
fs          0x30
gs          0x10
edi         0xc2f2e000
esi         0xcc1ca280
ebp         0xce96fcf0
ebx         0xcc1c4dc0
edx         0xcc1ca280
ecx         0xc2f2e048
eax         0
eip         0xc05103f5  x86_stihlt+0x5
cs          0x8
eflags      0x282
esp         0xce96fcf0
ss          0x10
netbsd:x86_stihlt+0x5:  leave

db{0}> show uvmexp
Current UVM status:
  pagesize=4096 (0x1000), pagemask=0xfff, pageshift=12
  512789 VM pages: 223514 active, 138610 inactive, 1743 wired, 60509 free
  pages  16223 anon, 344287 file, 3357 exec
  freemin=64, free-target=85, wired-max=170929
  faults=93891663, traps=93555851, intrs=946045, ctxswitch=12861625
  softint=6474966, syscalls=122742819, swapins=389, swapouts=412
  fault counts:
    noram=4, noanon=0, pgwait=0, pgrele=0
    ok relocks(total)=9866(9867), anget(retrys)=13503214(0), amapcopy=5851895
    neighbor anon/obj pg=11048110/74963905, gets(lock/unlock)=17759694/9867
    cases: anon=10074662, anoncow=2775671, obj=15491233, prcopy=2268417, 
przero=60010471
  daemon and swap counts:
    woke=2578, revs=2570, scans=747513, obscans=728383, anscans=0
    busy=0, freed=728383, reactivate=360, deactivate=1243021
    pageouts=0, pending=0, nswget=0
    nswapdev=1, swpgavail=1049705
    swpages=1049705, swpginuse=0, swpgonly=0, paging=0

Here is a top output while the crash happend:

load averages:  1.05,  1.07,  1.01;               up 0+02:40:30                 
           03:26:13
42 processes: 40 sleeping, 2 on CPU
CPU0 states:  4.7% user,  0.0% nice,  0.6% system,  0.0% interrupt, 94.6% idle
CPU1 states: 85.3% user,  0.0% nice,  9.7% system,  0.0% interrupt,  5.0% idle
Memory: 953M Act, 541M Inact, 6964K Wired, 13M Exec, 1345M File, 156M Free
Swap: 4100M Total, 4100M Free

>How-To-Repeat:
        I got it now twice while compillig openoffice2.
>Fix: