>Number:         7578
>Category:       kern
>Synopsis:       panic: pagedaemon: clean anon page without backing store?
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    kern-bug-people (Kernel Bug People)
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu May 13 17:20:01 1999
>Last-Modified:
>Originator:     Bill Sommerfeld
>Organization:
	
>Release:        1.4
>Environment:
	NetBSD heap.epilogue.com 1.4 NetBSD 1.4 (HEAPII) #64: Mon May 10 12:09:00 EDT 1999
	wes@heap.epilogue.com:/usr/sommerfeld/NetBSD-sys/arch/i386/compile/HEAPII i386

>Description:
	system panic'ed with above message.  i have saved teh crash
	dump and have a matching netbsd.gdb with symbols..

Here's what I can extract from the crash:

#0  0xf01cfd12 in uvm_pageout () at ../../../../uvm/uvm_pdaemon.c:309
#1  0xf01d78b7 in cpu_reboot (howto=256, bootstr=0x0)
    at ../../../../arch/i386/i386/machdep.c:1350
#2  0xf013a690 in log (level=-266535662, fmt=0xf030f1f0 "??/??l0?")
    at ../../../../kern/subr_prf.c:212
#3  0xf01cffc9 in uvmpd_scan_inactive (pglst=0xf02786c0)
    at ../../../../uvm/uvm_pdaemon.c:514
#4  0xf01d049f in uvmpd_scan () at ../../../../uvm/uvm_pdaemon.c:998
#5  0xf01cfc73 in uvm_pageout () at ../../../../uvm/uvm_pdaemon.c:294
#6  0xf01287c8 in start_pagedaemon (arg=0x0)
    at ../../../../kern/init_main.c:581

(gdb) frame 3
#3  0xf01cffc9 in uvmpd_scan_inactive (pglst=0xf02786c0)
    at ../../../../uvm/uvm_pdaemon.c:514
(gdb) print anon
$8 = {an_ref = 1, an_lock = {lock_data = 0}, u = {an_nxt = 0xf030b944,
    an_page = 0xf030b944}, an_swslot = 0}

at this point, p's just been passed to uvm_pagefree() so it's
presumably toast.

(gdb) print *p
$10 = {pageq = {tqe_next = 0xf0323584, tqe_prev = 0xf0348024}, hashq = {
    tqe_next = 0x0, tqe_prev = 0xf03dc558}, listq = {tqe_next = 0xf03473c0,
    tqe_prev = 0xf036cb08}, offset = 3735928559, uobject = 0xdeadbeef,
  uanon = 0xdeadbeef, flags = 8, version = 76, wire_count = 0, pqflags = 1,
  loan_count = 0, phys_addr = 27611136}

Anything else i should look for?

>How-To-Repeat:

Showed up during regular use.

system config:

NetBSD 1.4 (HEAPII) #64: Mon May 10 12:09:00 EDT 1999
    wes@heap.epilogue.com:/usr/sommerfeld/NetBSD-sys/arch/i386/compile/HEAPII
cpu0: family 6 model 3 step 4
cpu0: Intel Pentium II (686-class)
real mem  = 66703360
avail mem = 46407680
using 2822 buffers containing 16777216 bytes of memory
biostramp installed @ 1000
mainbus0 (root)
pci0 at mainbus0 bus 0: configuration mode 1
pci0: i/o enabled, memory enabled
pchb0 at pci0 dev 0 function 0
pchb0: vendor 0x8086 product 0x7180 (rev. 0x03)
ppb0 at pci0 dev 1 function 0: vendor 0x8086 product 0x7181 (rev. 0x03)
pci1 at ppb0 bus 1
pci1: i/o enabled, memory enabled
pcib0 at pci0 dev 4 function 0
pcib0: vendor 0x8086 product 0x7110 (rev. 0x01)
pciide0 at pci0 dev 4 function 1: Intel 82371AB IDE controller (PIIX4)
pciide0: bus-master DMA support present
pciide0: primary channel wired to compatibility mode
pciide0: disabling primary channel (no drives)
pciide0: secondary channel wired to compatibility mode
wd0 at pciide0 channel 1 drive 0: <Maxtor 91728D8>
wd0: drive supports 16-sector pio transfers, lba addressing
wd0: 16479MB, 16383 cyl, 16 head, 63 sec, 512 bytes/sect x 33750864 sectors
wd0: 32-bits data port
wd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 2
pciide0: secondary channel interrupting at irq 15
wd0(pciide0:1:0): using PIO mode 4, Ultra-DMA mode 2 (using DMA data transfers)
uhci0 at pci0 dev 4 function 2: vendor 0x8086 product 0x7112 (rev. 0x01)
uhci0: interrupting at irq 9
uhci0: USB version 1.0
usb0 at uhci0
uhub0 at usb0
uhub0: vendor 0x8086 UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub0: 2 ports with 2 removable, self powered
vendor 0x8086 product 0x7113 (miscellaneous bridge, revision 0x01) at pci0 dev 4 function 3 not configured
ahc0 at pci0 dev 6 function 0
ahc0: interrupting at irq 9
ahc0: Reading SEEPROM...done.
ahc0: aic7880 Wide Channel, SCSI Id=7, 16 SCBs
ahc0: Resetting Channel A
ahc0: Downloading Sequencer Program...Done
scsibus0 at ahc0 channel 0: 16 targets, 8 luns per target
ahc0: target 0 synchronous at 10.0MHz, offset = 0xf
ahc0: target 0 Tagged Queuing Device
sd0 at scsibus0 targ 0 lun 0: <SEAGATE, ST15150N, 5108> SCSI2 0/direct fixed
sd0: 4095MB, 3712 cyl, 21 head, 107 sec, 512 bytes/sect x 8388315 sectors
ahc0:A:1: refuses WIDE negotiation.  Using 8bit transfers
ahc0: target 1 synchronous at 10.0MHz, offset = 0xf
cd0 at scsibus0 targ 1 lun 0: <MATSHITA, CD-ROM CR-508, XS03> SCSI2 5/cdrom removable
de0 at pci0 dev 10 function 0
de0: interrupting at irq 10
de0: SMC 21041 [10Mb/s] pass 2.1
de0: address 00:e0:29:10:5c:f2
vga1 at pci0 dev 12 function 0: vendor 0x102b product 0x0519 (rev. 0x01)
wsdisplay0 at vga1: console (80x25, vt100 emulation)
wsdisplay0: screen 1 added (80x25, vt100 emulation)
wsdisplay0: screen 2 added (80x25, vt100 emulation)
wsdisplay0: screen 3 added (80x25, vt100 emulation)
wsdisplay0: screen 4 added (80x25, vt100 emulation)
wsdisplay0: screen 5 added (80x25, vt100 emulation)
wsdisplay0: screen 6 added (80x25, vt100 emulation)
wsdisplay0: screen 7 added (80x25, vt100 emulation)
isa0 at pcib0
com0 at isa0 port 0x3f8-0x3ff irq 4: ns16550a, working fifo
com1 at isa0 port 0x2f8-0x2ff irq 3: ns16550a, working fifo
pckbc0 at isa0 port 0x60-0x64 irq 1
pckbd0 at pckbc0 (kbd slot)
pckbc0: using irq 1 for kbd slot
wskbd0 at pckbd0: console keyboard
opms0 at pckbc0 (aux slot)
pckbc0: using irq 12 for aux slot
pcppi0 at isa0 port 0x61
midi0 at pcppi0: <PC speaker>
sysbeep0 at pcppi0
isapnp0 at isa0 port 0x279: ISA Plug 'n Play device support
npx0 at isa0 port 0xf0-0xff: using exception 16
fdc0 at isa0 port 0x3f0-0x3f7 irq 6 drq 2
fd0 at fdc0 drive 0: 1.44MB, 80 cyl, 2 head, 18 sec
isapnp0: read port 0x203
sb0 at isapnp0 port 0x220/16,0x330/2,0x388/4 irq 5 drq 1,5
sb0: Creative ViBRA16C PnP Audio: dsp v4.13
midi1 at sb0: <MPU-401 MIDI UART>
audio0 at sb0: full duplex
opl at sb0 not configured
joy0 at isapnp0 port 0x200/8
joy0: Creative ViBRA16C PnP Game
joy0: joystick not connected
apm0 at mainbus0: Power Management spec V1.1
apm0: A/C state: on
apm0: battery charge state: no battery
biomask 8240 netmask 8640 ttymask 9642
de0: enabling 10baseT port
wscons: wskbd0 glued to wsdisplay0 (console)
findroot: can't open dev wd0a (6)
boot device: sd0
root on sd0a dumps on sd0b
init: copying out path `/sbin/init' 11
IP Filter: initialized.  Default = pass all, Logging = enabled
de0: enabling 10baseT port

>Fix:
	unknown.				
>Audit-Trail:
>Unformatted: