>Number:         4081
>Category:       kern
>Synopsis:       mount/eject combination causes load increasion with ATAPI cdrom
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people (Kernel Bug People)
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Sep  4 02:35:02 1997
>Last-Modified:
>Originator:     Thorsten Frueauf
>Organization:
private
	
>Release:        <NetBSD-current source date> NetBSD current 03.09.1997
>Environment:
	
System: NetBSD cyberlap 1.2G NetBSD 1.2G (CYBERLAP) #2: Thu Sep 4 10:37:32 CEST 1997 frueauf@cyberlap:/usr/src/sys/arch/i386/compile/CYBERLAP i386

cpu0: family 5 model 2 step c
cpu0: Intel Pentium (P54C) (586-class)
real mem  = 50065408
avail mem = 45125632
using 636 buffers containing 2605056 bytes of memory
mainbus0 (root)
pci0 at mainbus0 bus 0: configuration mode 1
Toshiba Info Systems (2nd PCI Vendor ID) product 0x0601 (host bridge, revision 0x11) at pci0 dev 0 function 0 not configured
Chips and Technologies 65550 (VGA display, revision 0x05) at pci0 dev 4 function 0 not configured
isa0 at mainbus0
com0 at isa0 port 0x3f8-0x3ff irq 4: ns16550a, working fifo
lpt0 at isa0 port 0x378-0x37b irq 7
wdc0 at isa0 port 0x1f0-0x1f7 irq 14
atapibus0 at wdc0
wd0 at wdc0 drive 0: <TOSHIBA MK2101MAN>
wd0: 2067MB, 4200 cyl, 16 head, 63 sec, 512 bytes/sec
wd0: using 16-sector 16-bit pio transfers, lba addressing
wdc1 at isa0 port 0x170-0x177 irq 15
atapibus1 at wdc1
cd0 at atapibus1 drive 0: <TOSHIBA CD-ROM XM-1402B, 7510115238, 0186> type 5 cdrom removable
sb0 at isa0 port 0x220-0x237 irq 5 drq 1: dsp v3.02
audio0 at sb0
pcicmaster0 at isa0 port 0x3e0-0x3e1
pcic0 at pcicmaster0: Intel 82365sl Rev. 1 slots 0-1 iomem d4000-d4fff irq 11
pcmcia0 at pcic0
pcmcia0: slot 0 contains <3Com Corporation, 3C589, TP/BNC LAN Card Ver. 2a, 000002>
ep0 at pcmcia0 port 0x300-0x30f irq 10 drq2 -126352896: 3Com 3C589 Ethernet
ep0: MAC address 00:60:97:40:bc:a7
ep0: 8KB byte-wide FIFO, 5:3 Rx:Tx split, utp/aui/bnc (default utp)
pcmcia0: slot 1 is empty
npx0 at isa0 port 0xf0-0xff: using exception 16
vt0 at isa0 port 0x60-0x6f irq 1
vt0: generic, 80 col, color, 8 scr, mf2-kbd, [R3.32]
pms0 at vt0 irq 12
spkr0 at vt0 port 0x61
vt0: console
fdc0 at isa0 port 0x3f0-0x3f7 irq 6 drq 2
apm0 at mainbus0: Power Management spec V1.1
apm0: battery life expectancy: 99%
apm0: A/C state: on
apm0: battery charge state: high charging
apm0: estimated 1h 31m
biomask c040 netmask c440 ttymask dcc2
boot device: wd0
root on wd0a dumps on wd0b
root file system type: ffs

>Description:
	
On a total idle system one can cause a constant 1.0 load with just
mounting an ATAPI cdrom in combination with ejecting it. The load
keeps as long at 1.0 until one trys some mount/umount combinations,
then it calms down to 0.x (normal idle).

>How-To-Repeat:
	

Try the following on a fresh rebooted system with above hardware - maybe it
is enough to just have an ATAPI cdrom:

mount -t cd9660 -o ro /dev/cd0a /cdrom
ls -la /cdrom
eject cd0
# /* now you can watch the load increasing to 1.0 - constant */
mount -t cd9660 -o ro /dev/cd0a /cdrom
ls -la /cdrom
umount /cdrom
mount -t cd9660 -o ro /dev/cd0a /cdrom
ls -la /cdrom
umount /cdrom
# /* maybe you need some more of those combinations - but suddenly you can
#    watch the load calming down to 0.x again. */

Note that `top` or `ps` do not show anything that points to a process that
could cause that load, so I think its a kernel problem.

I had also no message on the console that indicates an error. The cdrom
just works as expected - only he load increasion is confusing.

>Fix:
	
None known, sorry :-(
>Audit-Trail:
>Unformatted:
mount/eject combination causes load increasion with ATAPI cdrom